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Sample records for mesoporous sorbent materials

  1. Lanthanide Selective Sorbents: Self-Assembled Monolayers on Mesoporous Supports (SAMMS)

    Fryxell, Glen E.; Wu, Hong; Lin, Yuehe; Shaw, Wendy J.; Birnbaum, Jerome C.; Linehan, John C.; Nie, Zimin; Kemner, Kenneth M.; Kelly, Shelley

    2004-11-01

    Through the marriage of mesoporous ceramics with self-assembled monolayer chemistry, the genesis of a powerful new class of environmental sorbent materials has been realized. By coating the mesoporous ceramic backbone with a monolayer terminated with a lanthanide-specific ligand, it is possible to couple high lanthanide binding affinity with the high loading capacity (resulting from the extremely high surface area of the support). This lanthanide-specific ligand field is created by pairing a “hard” anionic Lewis base with a suitable synergistic ligand, in a favorable chelating geometry. Details of the synthesis, characterization, lanthanide binding studies, binding kinetics, competition experiments and sorbent regeneration studies are summarized.

  2. Imprint-coating synthesis of selective functionalized ordered mesoporous sorbents for separation and sensors

    Dai, Sheng; Burleigh, Mark C.; Shin, Yongsoon

    2001-01-01

    The present invention relates generally to mesoporous sorbent materials having high capacity, high selectivity, fast kinetics, and molecular recognition capability. The invention also relates to a process for preparing these mesoporous substrates through molecular imprinting techniques which differ from convention techniques in that a template molecule is bound to one end of bifunctional ligands to form a complex prior to binding of the bifunctional ligands to the substrate. The present invention also relates to methods of using the mesoporous sorbent materials, for example, in the separation of toxic metals from process effluents, paints, and other samples; detection of target molecules, such as amino acids, drugs, herbicides, fertilizers, and TNT, in samples; separation and/or detection of substances using chromatography; imaging agents; sensors; coatings; and composites.

  3. Sorption of radionuclides on mesoporous Sn(IV) silicate: a new sorbent

    Sepehrian, H. [Jaber Ibn Hayan Research Labs., Nuclear Science and Technology Research Inst., AEOI, Tehran (Iran); Dept. of Applied Chemistry, Univ. of Tarbiat Moallem, Tehran (Iran); Yavari, R.; Ghannadi Maragheh, M. [Jaber Ibn Hayan Research Labs., Nuclear Science and Technology Research Inst., AEOI, Tehran (Iran); Husain, S.W. [Dept. of Applied Chemistry, Univ. of Tarbiat Moallem, Tehran (Iran)

    2008-07-01

    Four different samples of mesoporous Sn(IV) silicate with varying mole ratio of Si/Sn have been used to study the sorption behavior of 18 radionuclides on these materials. Ion-exchange capacity, SEM, distribution coefficient and chemical stability have been studied and discussed. Separation of Tl(I) from Th(IV), Cs(I) from Th(IV) and Cs(I) from Zr(IV) have been developed on columns of this sorbent. (orig.)

  4. Sorption of radionuclides on mesoporous Sn(IV) silicate: a new sorbent

    Sepehrian, H.; Yavari, R.; Ghannadi Maragheh, M.; Husain, S.W.

    2008-01-01

    Four different samples of mesoporous Sn(IV) silicate with varying mole ratio of Si/Sn have been used to study the sorption behavior of 18 radionuclides on these materials. Ion-exchange capacity, SEM, distribution coefficient and chemical stability have been studied and discussed. Separation of Tl(I) from Th(IV), Cs(I) from Th(IV) and Cs(I) from Zr(IV) have been developed on columns of this sorbent. (orig.)

  5. Lanthanide Selective Sorbents: Self-Assembled Monolayers on Mesoporous Supports (SAMMS)

    Fryxell, Glen E.; Wu, Hong; Lin, Yuehe; Shaw, Wendy J.; Birnbaum, Jerome C.; Linehan, John C.; Nie, Zimin; Kemner, K. M.; Kelly, Shelley

    2004-11-01

    Through the marriage of mesoporous ceramics with self-assembled monolayer chemistry, the genesis of a powerful new class of environmental sorbent materials has been realized. By coating the mesoporous ceramic backbone with a monolayer terminated with a lanthanide-specific ligand, it is possible to couple high lanthanide binding affinity with the high loading capacity (resulting from the extremely high surface area of the support). This lanthanide-specific ligand field is created by pairing a ''hard'' anionic Lewis base with a suitable synergistic ligand, in a favorable chelating geometry. Details of the synthesis, characterization, lanthanide binding studies, binding kinetics, competition experiments and sorbent regeneration studies are summarized

  6. Mesoporous carbon materials

    Dai, Sheng; Fulvio, Pasquale Fernando; Mayes, Richard T.; Wang, Xiqing; Sun, Xiao-Guang; Guo, Bingkun

    2014-09-09

    A conductive mesoporous carbon composite comprising conductive carbon nanoparticles contained within a mesoporous carbon matrix, wherein the conductive mesoporous carbon composite possesses at least a portion of mesopores having a pore size of at least 10 nm and up to 50 nm, and wherein the mesopores are either within the mesoporous carbon matrix, or are spacings delineated by surfaces of said conductive carbon nanoparticles when said conductive carbon nanoparticles are fused with each other, or both. Methods for producing the above-described composite, devices incorporating them (e.g., lithium batteries), and methods of using them, are also described.

  7. High efficiency nanocomposite sorbents for CO2 capture based on amine-functionalized mesoporous capsules

    Qi, Genggeng; Wang, Yanbing; Estevez, Luis; Duan, Xiaonan; Anako, Nkechi; Park, Ah-Hyung Alissa; Li, Wen; Jones, Christopher W.; Giannelis, Emmanuel P.

    2011-01-01

    A novel high efficiency nanocomposite sorbent for CO2 capture has been developed based on oligomeric amine (polyethylenimine, PEI, and tetraethylenepentamine, TEPA) functionalized mesoporous silica capsules. The newly synthesized sorbents exhibit extraordinary capture capacity up to 7.9 mmol g-1 under simulated flue gas conditions (pre-humidified 10% CO 2). The CO2 capture kinetics were found to be fast and reached 90% of the total capacities within the first few minutes. The effects of the mesoporous capsule features such as particle size and shell thickness on CO2 capture capacity were investigated. Larger particle size, higher interior void volume and thinner mesoporous shell thickness all improved the CO2 capacity of the sorbents. PEI impregnated sorbents showed good reversibility and stability during cyclic adsorption-regeneration tests (50 cycles). © 2011 The Royal Society of Chemistry.

  8. Efficient CO2 sorbents based on silica foam with ultra-large mesopores

    Qi, Genggeng; Fu, Liling; Choi, Brian Hyun; Giannelis, Emmanuel P.

    2012-01-01

    A series of high-capacity, amine impregnated sorbents based on a cost-effective silica foam with ultra-large mesopores is reported. The sorbents exhibit fast CO2 capture kinetics, high adsorption capacity (of up to 5.8 mmol g-1 under 1 atm of dry CO2), as well as good stability over multiple adsorption-desorption cycles. A simple theoretical analysis is provided relating the support structure to sorbent performance. © 2012 The Royal Society of Chemistry.

  9. Gyroidal mesoporous carbon materials and methods thereof

    Wiesner, Ulrich B.; Werner, Joerg G.

    2017-07-25

    The present invention relates to, inter alia, gyroidal mesoporous carbon materials and methods of use and manufacture thereof. In one embodiment, the present invention relates to a mesoporous carbon composition comprising a gyroidal mesoporous carbon having an ordered gyroidal structure and mesopores having a pore size of greater than 2 nanometers (nm) in diameter, and more particularly greater than 11 nm in diameter.

  10. Ionic liquid-functionalized mesoporous sorbents and their use in the capture of polluting gases

    Lee, Jong Suk; Koros, William J.; Bhuwania, Nitesh; Hillesheim, Patrick C.; Dai, Sheng

    2016-01-12

    A composite structure for capturing a gaseous electrophilic species, the composite structure comprising mesoporous refractory sorbent particles on which an ionic liquid is covalently attached, wherein said ionic liquid includes an accessible functional group that is capable of binding to said gaseous electrophilic species. In particular embodiments, the mesoporous sorbent particles are contained within refractory hollow fibers. Also described is a method for capturing a gaseous electrophilic species by use of the above-described composite structure, wherein the gaseous electrophilic species is contacted with the composite structure. In particular embodiments thereof, cooling water is passed through the refractory hollow fibers containing the IL-functionalized sorbent particles in order to facilitate capture of the gaseous electrophilic species, and then steam is passed through the refractory hollow fibers to facilitate release of the gaseous electrophilic species such that the composite structure can be re-used to capture additional gas.

  11. Mesoporous Silicate Materials in Sensing

    Paul T. Charles

    2008-08-01

    Full Text Available Mesoporous silicas, especially those exhibiting ordered pore systems and uniform pore diameters, have shown great potential for sensing applications in recent years. Morphological control grants them versatility in the method of deployment whether as bulk powders, monoliths, thin films, or embedded in coatings. High surface areas and pore sizes greater than 2 nm make them effective as adsorbent coatings for humidity sensors. The pore networks also provide the potential for immobilization of enzymes within the materials. Functionalization of materials by silane grafting or through cocondensation of silicate precursors can be used to provide mesoporous materials with a variety of fluorescent probes as well as surface properties that aid in selective detection of specific analytes. This review will illustrate how mesoporous silicas have been applied to sensing changes in relative humidity, changes in pH, metal cations, toxic industrial compounds, volatile organic compounds, small molecules and ions, nitroenergetic compounds, and biologically relevant molecules.

  12. Micelle swelling agent derived cavities for increasing hydrophobic organic compound removal efficiency by mesoporous micelle@silica hybrid materials

    Shi, Yifeng; Li, Bin; Wang, Peng; Dua, Rubal; Zhao, Dongyuan

    2012-01-01

    Mesoporous micelle@silica hybrid materials with 2D hexagonal mesostructures were synthesized as reusable sorbents for hydrophobic organic compounds (HOCs) removal by a facile one-step aqueous solution synthesis using 3-(trimethoxysily)propyl

  13. Sorption of agrochemical model compounds by sorbent materials containing beta-cyclodextrin.

    Wilson, Lee D; Mohamed, Mohamed H; Guo, Rui; Pratt, Dawn Y; Kwon, Jae Hyuck; Mahmud, Sarker T

    2010-04-01

    Polymeric sorbent materials that incorporate beta-cyclodextrin (CD) have been prepared and their sorption behavior toward two model agrochemical contaminant compounds, p-nitrophenol (PNP) and methyl chloride examined. The sorption of PNP was studied in aqueous solution using ultraviolet-visible (UV-Vis) spectroscopy, whereas the sorption of methyl chloride from the gas phase was studied using a Langmuir adsorption method. The sorption results for PNP in solution were compared between granular activated carbon (GAC), modified GAC, CD copolymers, and CD-based mesoporous silica hybrid materials. Nitrogen porosimetry at 77 K was used to estimate the surface area and pore structure properties of the sorbent materials. The sorbents displayed variable surface areas as follows: copolymers (36.2-157 m(2)/g), CD-silica materials (307-906 m(2)/g), surface modified GAC (657 m(2)/g), and granular activated carbon (approximately 10(3) m(2)/g). The sorption capacities for PNP and methyl chloride with the different sorbents are listed in descending order as follows: GAC > copolymers > surface modified GAC > CD-silica hybrid materials. In general, the differences in the sorption properties of the sorbents were related to the following: (i) surface area of the sorbent, (ii) CD content and accessibility, (iii) and the chemical nature of the sorbent material.

  14. Miniaturized solid-phase extraction of macrolide antibiotics in honey and bovine milk using mesoporous MCM-41 silica as sorbent.

    Du, Li-Jing; Yi, Ling; Ye, Li-Hong; Chen, Yu-Bo; Cao, Jun; Peng, Li-Qing; Shi, Yu-Ting; Wang, Qiu-Yan; Hu, Yu-Han

    2018-02-16

    A simple and effective method of miniaturized solid-phase extraction (mini-SPE) was developed for the simultaneous purification and enrichment of macrolide antibiotics (MACs) (i.e. azithromycin, clarithromycin, erythromycin, lincomycin and roxithromycin) from honey and skim milk. Mesoporous MCM-41 silica was synthesized and used as sorbent in mini-SPE. Several key parameters affecting the performance of mini-SPE procedure were thoroughly investigated, including sorbent materials, amount of sorbent and elution solvents. Under the optimized condition, satisfactory linearity (r 2  > 0.99), acceptable precision (RSDs, 0.3-7.1%), high sensitivity (limit of detection in the range of 0.01-0.76 μg/kg), and good recoveries (83.21-105.34%) were obtained. With distinct advantages of simplicity, reliability and minimal sample requirement, the proposed mini-SPE procedure coupled with ultrahigh performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry could become an alternative tool to analyze the residues of MACs in complex food matrixes. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Organically functionalized mesoporous SBA-15 as sorbents for removal of selected pharmaceuticals from water

    Bui, Tung Xuan [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), 261 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of); Kang, Seo-Young [International Environmental Research Center (IERC), Gwangju Institute of Science and Technology (GIST), 261 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of); Lee, Sang-Hyup [Water Environment Center, Korea Institute of Science and Technology, Cheongryang, Seoul 130-650 (Korea, Republic of); Choi, Heechul, E-mail: hcchoi@gist.ac.kr [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), 261 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of)

    2011-10-15

    Highlights: {yields} SBA-15 grafted with aminopropyl, hydroxymethyl, and trimethylsilyl groups as sorbents. {yields} Sorbents for removal of a mixture of 12 pharmaceuticals from water. {yields} Hydroxymethyl-SBA-15 shows similar adsorption efficiency like SBA-15. {yields} Aminopropyl-SBA-15 makes increase for clofibric acid, diclofenac, decrease for atenolol, estrone, trimethoprim. {yields} Trimethylsilyl-SBA-15 makes increase for 9 compounds; 7 compounds from 70.6% to 98.9%. - Abstract: Mesoporous silica SBA-15 and its postfunctionalized counterparts with hydroxymethyl (HM-SBA-15), aminopropyl (AP-SBA-15), and trimethylsilyl (TMS-SBA-15) were prepared and characterized by powder X-ray diffraction, N{sub 2} adsorption-desorption measurement, Fourier-transform infrared spectroscopy, and elemental analysis. The removal of a mixture of 12 selected pharmaceuticals was investigated by batch adsorption experiments onto SBA-15 and the grafted materials. SBA-15 showed to have moderate adsorption affinity with amino-containing (atenolol, trimethoprim) and hydrophobic pharmaceuticals, but it displayed minimal adsorption affinity toward hydrophilic compounds. HM-SBA-15 was analogous with SBA-15 in terms of the adsorption efficiency toward all pharmaceuticals. AP-SBA-15 exhibited an increase in the adsorption of two acidic compounds (clofibric acid, diclofenac) but a decrease in the adsorption of estrone and the two amino-containing compounds. Among the grafted materials, TMS-SBA-15 had the highest adsorption affinity toward most pharmaceuticals. Moreover, the adsorption of nine pharmaceuticals to TMS-SBA-15 was significantly higher than that to SBA-15; seven of which showed the removal percentages from 70.6% to 98.9% onto TMS-SBA-15. The number of pharmaceuticals showing high adsorption efficiency onto TMS-SBA-15 did not alter significantly as the pH changed in the range of 5.5-7.6. The results suggest that TMS-SBA-15 is a promising material for the removal of pharmaceuticals

  16. Organically functionalized mesoporous SBA-15 as sorbents for removal of selected pharmaceuticals from water

    Bui, Tung Xuan; Kang, Seo-Young; Lee, Sang-Hyup; Choi, Heechul

    2011-01-01

    Highlights: → SBA-15 grafted with aminopropyl, hydroxymethyl, and trimethylsilyl groups as sorbents. → Sorbents for removal of a mixture of 12 pharmaceuticals from water. → Hydroxymethyl-SBA-15 shows similar adsorption efficiency like SBA-15. → Aminopropyl-SBA-15 makes increase for clofibric acid, diclofenac, decrease for atenolol, estrone, trimethoprim. → Trimethylsilyl-SBA-15 makes increase for 9 compounds; 7 compounds from 70.6% to 98.9%. - Abstract: Mesoporous silica SBA-15 and its postfunctionalized counterparts with hydroxymethyl (HM-SBA-15), aminopropyl (AP-SBA-15), and trimethylsilyl (TMS-SBA-15) were prepared and characterized by powder X-ray diffraction, N 2 adsorption-desorption measurement, Fourier-transform infrared spectroscopy, and elemental analysis. The removal of a mixture of 12 selected pharmaceuticals was investigated by batch adsorption experiments onto SBA-15 and the grafted materials. SBA-15 showed to have moderate adsorption affinity with amino-containing (atenolol, trimethoprim) and hydrophobic pharmaceuticals, but it displayed minimal adsorption affinity toward hydrophilic compounds. HM-SBA-15 was analogous with SBA-15 in terms of the adsorption efficiency toward all pharmaceuticals. AP-SBA-15 exhibited an increase in the adsorption of two acidic compounds (clofibric acid, diclofenac) but a decrease in the adsorption of estrone and the two amino-containing compounds. Among the grafted materials, TMS-SBA-15 had the highest adsorption affinity toward most pharmaceuticals. Moreover, the adsorption of nine pharmaceuticals to TMS-SBA-15 was significantly higher than that to SBA-15; seven of which showed the removal percentages from 70.6% to 98.9% onto TMS-SBA-15. The number of pharmaceuticals showing high adsorption efficiency onto TMS-SBA-15 did not alter significantly as the pH changed in the range of 5.5-7.6. The results suggest that TMS-SBA-15 is a promising material for the removal of pharmaceuticals from aqueous phase

  17. Ordered mesoporous silica materials with complicated structures

    Han, Yu

    2012-05-01

    Periodically ordered mesoporous silicas constitute one of the most important branches of porous materials that are extensively employed in various chemical engineering applications including adsorption, separation and catalysis. This short review gives an introduction to recently developed mesoporous silicas with emphasis on their complicated structures and synthesis mechanisms. In addition, two powerful techniques for solving complex mesoporous structures, electron crystallography and electron tomography, are compared to elucidate their respective strength and limitations. Some critical issues and challenges regarding the development of novel mesoporous structures as well as their applications are also discussed. © 2011 Elsevier Ltd.

  18. Amine-functionalized mesoporous polymer as potential sorbent for nickel preconcentration from electroplating wastewater.

    Islam, Aminul; Zaidi, Noushi; Ahmad, Hilal; Kumar, Suneel

    2015-05-01

    In this study, mesoporous glycidyl methacrylate-divinylbenzene-based chelating resin was synthesized and grafted with diethylenetriamine through epoxy ring-opening reaction. The synthesized resin was characterized by elemental analysis, infrared spectroscopy, surface area and pore size analysis, scanning electron microscopy, energy-dispersive spectroscopy, and thermogravimetry. The resin was used for the first time as an effective sorbent for the preconcentration of nickel in electroplating wastewater samples. The analytical variables like pH, flow rate for sorption/desorption, and eluate selection were systematically investigated and optimized. The uniform and monolayer sorption behavior of resin for nickel was proved by an evident fit of the equilibrium data to a Langmuir isotherm model. Under optimized conditions, the resin was observed to show a good sorption capacity of 20.25 mg g(-1) and >96% recovery of nickel even in the presence of a large number of competitive matrix ions. Its ability to extract trace amount of nickel was exhibited by low preconcentration limit (5.9 μg L(-1)). The calibration curve was found to be linear (R(2) = 0.998) in the concentration range of 6.0-400.0 μg L(-1). Coefficient of variation of less than 5 for all the analysis indicated good reproducibility. The reliability was evaluated by the analysis of standard reference material (SRM) and recovery experiments. The applicability of the resin for the systematic preconcentration of nickel is substantiated by the analysis of electroplating wastewater and river water samples. Graphical abstract ᅟ.

  19. Hydrogen sulfide removal from hot coal gas by various mesoporous silica supported Mn2O3 sorbents

    Zhang, Z.F.; Liu, B.S.; Wang, F.; Wang, W.S.; Xia, C.; Zheng, S.; Amin, R.

    2014-01-01

    Graphical abstract: - Highlights: • Mn 2 O 3 /KIT-1 presented the best desulfurization performance at 600–850 °C. • High sulfur capacity of Mn 2 O 3 /KIT-1 correlated closely with 3-D channel of KIT-1. • Desulfurization character depended strongly on framework structure of sorbents. • High steam content suppressed greatly the occurrence of sulfidation reaction. - Abstract: A series of 50 wt% Mn 2 O 3 sorbents was prepared using various mesoporous silica, MCM-41, HMS, and KIT-1 as support. The influence of textural parameters of mesoporous silica, especially type of channel on the desulfurization performance of Mn 2 O 3 sorbents was investigated at 600–850 °C using hot coal gas containing 0.33 vol.% H 2 S. The fresh and used sorbents were characterized by means of N 2 -adsorption, x-ray diffraction (XRD), high resolution transmission microscopy (HRTEM) and H 2 temperature- programmed reduction (H 2 -TPR) techniques. The results confirmed that the manganese oxide was dispersed highly in regular pore channel of the mesoporous supports due to high surface area. Compared with the Mn 2 O 3 /diatomite, all mesoporous silica supported Mn 2 O 3 sorbents exhibited high breakthrough sulfur capacity and a sharp deactivation rate after the breakthrough point. Compared to Mn 2 O 3 /MCM-41 and Mn 2 O 3 /HMS sorbent, the Mn 2 O 3 /KIT-1 showed better desulfurization performance because of the 3D wormhole-like channel. The high sulfur capacity of the Mn 2 O 3 /KIT-1 sorbent was maintained during the eight consecutive desulfurization-regeneration cycles. The Mn 2 O 3 /KIT-1 still presented high desulfurization activity when hot coal gas contained low steam (<5%)

  20. Ordered mesoporous silica materials with complicated structures

    Han, Yu; Zhang, Daliang

    2012-01-01

    Periodically ordered mesoporous silicas constitute one of the most important branches of porous materials that are extensively employed in various chemical engineering applications including adsorption, separation and catalysis. This short review

  1. Functionalization of mesoporous materials for lanthanide and actinide extraction.

    Florek, Justyna; Giret, Simon; Juère, Estelle; Larivière, Dominic; Kleitz, Freddy

    2016-10-14

    Among the energy sources currently available that could address our insatiable appetite for energy and minimize our CO2 emission, solar, wind, and nuclear energy currently occupy an increasing portion of our energy portfolio. The energy associated with these sources can however only be harnessed after mineral resources containing valuable constituents such as actinides (Ac) and rare earth elements (REEs) are extracted, purified and transformed into components necessary for the conversion of energy into electricity. Unfortunately, the environmental impacts resulting from their manufacture including the generation of undesirable and, sometimes, radioactive wastes and the non-renewable nature of the mineral resources, to name a few, have emerged as challenges that should be addressed by the scientific community. In this perspective, the recent development of functionalized solid materials dedicated to selective elemental separation/pre-concentration could provide answers to several of the above-mentioned challenges. This review focuses on recent advances in the field of mesoporous solid-phase (SP) sorbents designed for REEs and Ac liquid-solid extraction. Particular attention will be devoted to silica and carbon sorbents functionalized with commonly known ligands, such as phosphorus or amide-containing functionalities. The extraction performances of these new systems are discussed in terms of sorption capacity and selectivity. In order to support potential industrial applications of the silica and carbon-based sorbents, their main drawbacks and advantages are highlighted and discussed.

  2. Quaternary ammonium-functionalized MCM-48 mesoporous silica as a sorbent for the dispersive solid-phase extraction of endocrine disrupting compounds in water.

    Zhang, Shijuan; Lu, Fengli; Ma, Xiaoyun; Yue, Mingbo; Li, Yanxin; Liu, Jiammin; You, Jinmao

    2018-07-06

    MCM-48 mesoporous silica was functionalized with dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, a quaternary ammonium salt with a long hydrophobic chain, to prepare a new sorbent for the dispersive solid-phase extraction (DSPE) of seven endocrine disrupting compounds (EDCs) including 4-hexylphenol, 4-octylphenol, 4-nonylphenol, bisphenol A, estrone, 17β-estradiol and estriol in water. A series of differently functionalized MCM-48 materials were also synthesized, and they served as reference materials to study the mechanism. The developed DSPE method was combined with HPLC with fluorescence detection to evaluate the adsorption performance. The results indicated that the quaternary ammonium-functionalized MCM-48 mesoporous silica can be used as ideal sorbent for EDCs in water with recoveries of higher than 95% due to the electrostatic interactions and hydrophobic effect. Hydrogen bonding and π-π interactions in other synthesized materials could lead to about 25-30% increase in recoveries, but the results for polyhydroxy compounds were still not satisfying. The quaternary ammonium-functionalized MCM-48 mesoporous silica was successfully applied to the DSPE of EDCs in real water samples. The optimum extraction conditions were sorbent amount, 15 mg; desorption time; 5 min; elution volume, 0.8 mL; sample pH 3.0; and salt addition, 5 g/L. The limits of detection were in the range of 1.2-2.6 ng/L, while the limits of quantitation were in the range of 4.3-8.3 ng/L. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Micelle swelling agent derived cavities for increasing hydrophobic organic compound removal efficiency by mesoporous micelle@silica hybrid materials

    Shi, Yifeng

    2012-06-01

    Mesoporous micelle@silica hybrid materials with 2D hexagonal mesostructures were synthesized as reusable sorbents for hydrophobic organic compounds (HOCs) removal by a facile one-step aqueous solution synthesis using 3-(trimethoxysily)propyl-octadecyldimethyl-ammonium chloride (TPODAC) as a structure directing agent. The mesopores were generated by adding micelle swelling agent, 1,3,5-trimethyl benzene, during the synthesis and removing it afterward, which was demonstrated to greatly increase the HOC removal efficiency. In this material, TPODAC surfactant is directly anchored on the pore surface of mesoporous silica via SiOSi covalent bond after the synthesis due to its reactive Si(OCH 3) 3 head group, and thus makes the synthesized materials can be easily regenerated for reuse. The obtained materials show great potential in water treatment as pollutants sorbents. © 2011 Elsevier Inc. All rights reserved.

  4. Soft-Templating Synthesis of Mesoporous Silica-Based Materials for Environmental Applications

    Gunathilake, Chamila Asanka

    Dissertation research is mainly focus on: 1) the development of mesoporous silica materials with organic pendant and bridging groups (isocyanurate, amidoxime, benzene) and incorporated metal (aluminum, zirconium, calcium, and magnesium) species for high temperature carbon dioxide (CO2) sorption, 2) phosphorous-hydroxy functionalized mesoporous silica materials for water treatment, and 3) amidoxime-modified ordered mesoporous silica materials for uranium sorption under seawater conditions. The goal is to design composite materials for environmental applications with desired porosity, surface area, and functionality by selecting proper metal oxide precursors, organosilanes, tetraethylorthosilicate, (TEOS), and block copolymer templates and by adjusting synthesis conditions. The first part of dissertation presents experimental studies on the merge of aluminum, zirconium, calcium, and magnesium oxides with mesoporous silica materials containing organic pendant (amidoxime) and bridging groups (isocyanurate, benzene) to obtain composite sorbents for CO2 sorption at ambient (0-25 °C) and elevated (60-120 °C) temperatures. These studies indicate that the aforementioned composite sorbents are fairly good for CO2 capture at 25 °C via physisorption mechanism and show a remarkably high affinity toward CO2 chemisorption at 60-120 °C. The second part of dissertation is devoted to silica-based materials with organic functionalities for removal of heavy metal ions such as lead from contaminated water and for recovery of metal ions such as uranium from seawater. First, ordered mesoporous organosilica (OMO) materials with diethylphosphatoethyl and hydroxyphosphatoethyl surface groups were examined for Pb2+ adsorption and showed unprecedented adsorption capacities up to 272 mg/g and 202 mg/g, respectively However, the amidoxime-modified OMO materials were explored for uranium extraction under seawater conditions and showed remarkable capacities reaching 57 mg of uranium per gram

  5. Preparation and characterization of multifunctional magnetic mesoporous calcium silicate materials

    Zhang, Jianhua; Tao, Cuilian; Zhu, Yufang; Zhu, Min; Li, Jie; Hanagata, Nobutaka

    2013-01-01

    We have prepared multifunctional magnetic mesoporous Fe–CaSiO 3 materials using triblock copolymer (P123) as a structure-directing agent. The effects of Fe substitution on the mesoporous structure, in vitro bioactivity, magnetic heating ability and drug delivery property of mesoporous CaSiO 3 materials were investigated. Mesoporous Fe–CaSiO 3 materials had similar mesoporous channels (5–6 nm) with different Fe substitution. When 5 and 10% Fe were substituted for Ca in mesoporous CaSiO 3 materials, mesoporous Fe–CaSiO 3 materials still showed good apatite-formation ability and had no cytotoxic effect on osteoblast-like MC3T3-E1 cells evaluated by the elution cell culture assay. On the other hand, mesoporous Fe–CaSiO 3 materials could generate heat to raise the temperature of the surrounding environment in an alternating magnetic field due to their superparamagnetic property. When we use gentamicin (GS) as a model drug, mesoporous Fe–CaSiO 3 materials release GS in a sustained manner. Therefore, magnetic mesoporous Fe–CaSiO 3 materials would be a promising multifunctional platform with bone regeneration, local drug delivery and magnetic hyperthermia. (paper)

  6. Potential of hybrid functionalized meso-porous materials for the separation and immobilization of radionuclides

    Luca, V.

    2013-01-01

    Functionalized meso-porous materials are a class of hybrid organic-inorganic material in which a meso-porous metal oxide framework is functionalized with multifunctional organic molecules. These molecules may contain one or more anchor groups that form strong bonds to the pore surfaces of the metal oxide framework and free functional groups that can impart and or modify the functionality of the material such as for binding metal ions in solution. Such materials have been extensively studied over the past decade and are of particular interest in absorption applications because of the tremendous versatility in choosing the composition and architecture of the metal oxide framework and the nature of the functional organic molecule as well as the efficient mass transfer that can occur through a well-designed hierarchically porous network. A sorbent for nuclear applications would have to be highly selective for particular radio nuclides, it would need to be hydrolytically and radiolytically stable, and it would have to possess reasonable capacity and fast kinetics. The sorbent would also have to be available in a form suitable for use in a column. Finally, it would also be desirable if once saturated with radio nuclides, the sorbent could be recycled or converted directly into a ceramic or glass waste form suitable for direct repository disposal or even converted directly into a material that could be used as a transmutation target. Such a cradle-to- grave strategy could have many benefits in so far as process efficiency and the generation of secondary wastes are concerned.This paper will provide an overview of work done on all of the above mentioned aspects of the development of functionalized meso-porous adsorbent materials for the selective separation of lanthanides and actinides and discuss the prospects for future implementation of a cradle-to-grave strategy with such materials. (author)

  7. Tunable polymeric sorbent materials for fractionation of model naphthenates.

    Mohamed, Mohamed H; Wilson, Lee D; Headley, John V

    2013-04-04

    The sorption properties are reported for several examples of single-component carboxylic acids representing naphthenic acids (NAs) with β-cyclodextrin (β-CD) based polyurethane sorbents. Seven single-component examples of NAs were chosen with variable z values, carbon number, and chemical structure as follows: 2-hexyldecanoic acid (z = 0 and C = 16; S1), n-caprylic acid (z = 0 and C = 8; S2), trans-4-pentylcyclohexanecarboxylic acid (z = -2 and C = 12; S3), 4-methylcyclohexanecarboxylic acid (z = -2 and C = 8; S4), dicyclohexylacetic acid (z = -4; C = 14; S5), 4-pentylbicyclo[2.2.2]octane-1-carboxylic acid (z = -4; C = 14; S6), and lithocholic acid (z = -6; C = 24; S7). The copolymer sorbents were synthesized at three relative β-CD:diisocyanate mole ratios (i.e., 1:1, 1:2, and 1:3) using 4,4'-dicyclohexylmethane diisocyanate (CDI) and 4,4'-diphenylmethane diisocyanate (MDI). The sorption properties of the copolymer sorbents were characterized using equilibrium sorption isotherms in aqueous solution at pH 9.00 with electrospray ionization mass spectrometry. The equilibrium fraction of the unbound carboxylate anions was monitored in the aqueous phase. The sorption properties of the copolymer sorbents (i.e., Qm) were obtained from the Sips isotherm model. The Qm values generally decrease as the number of accessible β-CD inclusion sites in the copolymer framework decreases. The chemical structure of the adsorbates played an important role in their relative uptake, as evidenced by the adsorbate lipophilic surface area (LSA) and the involvement of hydrophobic effects. The copolymers exhibit molecular selective sorption of the single-component carboxylates in mixtures which suggests their application as sorbents for fractionation of mixtures of NAs. By comparison, granular activated carbon (GAC) and chitosan sorbents did not exhibit any significant molecular selective sorption relative to the copolymer materials; however, evidence of variable sorption capacity was

  8. Synthesis and catalytic applications of combined zeolitic/mesoporous materials

    Jarian Vernimmen

    2011-11-01

    Full Text Available In the last decade, research concerning nanoporous siliceous materials has been focused on mesoporous materials with intrinsic zeolitic features. These materials are thought to be superior, because they are able to combine (i the enhanced diffusion and accessibility for larger molecules and viscous fluids typical of mesoporous materials with (ii the remarkable stability, catalytic activity and selectivity of zeolites. This review gives an overview of the state of the art concerning combined zeolitic/mesoporous materials. Focus is put on the synthesis and the applications of the combined zeolitic/mesoporous materials. The different synthesis approaches and formation mechanisms leading to these materials are comprehensively discussed and compared. Moreover, Ti-containing nanoporous materials as redox catalysts are discussed to illustrate a potential implementation of combined zeolitic/mesoporous materials.

  9. Synthesis of mesoporous triple-metal nanosorbent from layered double hydroxide as an efficient new sorbent for removal of dye from water and wastewater.

    Kostić, Miloš; Radović, Miljana; Velinov, Nena; Najdanović, Slobodan; Bojić, Danijela; Hurt, Andrew; Bojić, Aleksandar

    2018-09-15

    In this study, co-precipitation synthesis of the mesoporous triple-metal nanosorbent from Fe, Cu, Ni layered double hydroxide (FeCuNi-LDH), on the basis of the data obtained from the TG analysis was carried out. The FTIR spectroscopy and XRD results confirm the formation of CuO, NiO and Fe 2 O 3 nanoparticles, while the EDX analysis does not show significant variations on the surface in elemental composition. BET analysis shows that FeCuNi-280 (FeCuNi-LDH calcinated at 280 °C) with mesoporous structure, has larger surface area compared to FeCuNi-LDH and FeCuNi-550 (FeCuNi-LDH calcinated at 550 °C). The value of pH PZC of FeCuNi-280 is found to be 8.66. Obtained FeCuNi-280 material showed the ability for efficient removal of dye Reactive Blue 19 (RB19) from water, with a very high sorption capacity of 480.79 mg/g at optimal conditions: the sorbent dose of 0.6 g/dm 3 , stirring speed of 280 rpm and pH 2. The kinetics results of the sorption process were well fitted by pseudo-second order and Chrastil model, and the sorption isotherm was well described by Sips, Langmuir and Brouers-Sotolongo model. FeCuNi-280 was easily regenerated with aqueous solution of NaOH, and reutilization was successfully done in five sorption cycles. The present study show that easy-to-prepare, relatively inexpensive nanosorbent FeCuNi-280 is among the best sorbents for the removal of RB19 dye from water solution and wastewater from textile industry in wide range of pH. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. New hybrid materials as Zn(II) sorbents in water samples

    Perez-Quintanilla, Damian; Sanchez, Alfredo; Hierro, Isabel del; Fajardo, Mariano; Sierra, Isabel

    2010-01-01

    Mesoporous silicas have been chemically modified with 5-mercapto-1-methyltetrazole (MTTZ) obtaining hybrid materials denominated MTTZ-MSU-2 and MTTZ-HMS. These materials were employed as Zn(II) sorbents from aqueous media at room temperature. The effect of several variables (stirring time, pH, presence of other metals) has been studied using batch and column techniques. Flame atomic absorption spectrometry (FAAS) was used to determinate Zn(II) concentration in the filtrate or in the eluted solution after the adsorption process. The results indicate that under pH 8, the maximum adsorption value was 0.94 ± 0.01 and 0.72 ± 0.01 mmol Zn(II)/g for MTTZ-MSU-2 and MTTZ-HMS, respectively. In tap water samples, a preconcentration factor of 200 was obtained. On the basis of these results, it can be concluded that it is possible to modify chemically MSU-2 and HMS with 5-mercapto-1-methyltetrazole and to use the resulting modified mesoporous silica as an effective adsorbent for Zn(II) in aqueous media.

  11. Mesoporous materials for clean energy technologies.

    Linares, Noemi; Silvestre-Albero, Ana M; Serrano, Elena; Silvestre-Albero, Joaquín; García-Martínez, Javier

    2014-11-21

    Alternative energy technologies are greatly hindered by significant limitations in materials science. From low activity to poor stability, and from mineral scarcity to high cost, the current materials are not able to cope with the significant challenges of clean energy technologies. However, recent advances in the preparation of nanomaterials, porous solids, and nanostructured solids are providing hope in the race for a better, cleaner energy production. The present contribution critically reviews the development and role of mesoporosity in a wide range of technologies, as this provides for critical improvements in accessibility, the dispersion of the active phase and a higher surface area. Relevant examples of the development of mesoporosity by a wide range of techniques are provided, including the preparation of hierarchical structures with pore systems in different scale ranges. Mesoporosity plays a significant role in catalysis, especially in the most challenging processes where bulky molecules, like those obtained from biomass or highly unreactive species, such as CO2 should be transformed into most valuable products. Furthermore, mesoporous materials also play a significant role as electrodes in fuel and solar cells and in thermoelectric devices, technologies which are benefiting from improved accessibility and a better dispersion of materials with controlled porosity.

  12. Interface chemistry of nanostructured materials: ion adsorption on mesoporous alumina.

    Wang, Yifeng; Bryan, Charles; Xu, Huifang; Pohl, Phil; Yang, Yi; Brinker, C Jeffrey

    2002-10-01

    This paper presents a part of our work on understanding the effect of nanoscale pore space confinement on ion sorption by mesoporous materials. Acid-base titration experiments were performed on both mesoporous alumina and alumina particles under various ionic strengths. The point of zero charge (PZC) for mesoporous alumina was measured to be approximately 9.1, similar to that for nonmesoporous alumina materials, indicating that nanoscale pore space confinement does not have a significant effect on the PZC of pore surfaces. However, for a given pH deviation from the PZC, (pH-PZC), the surface charge per mass on mesoporous alumina was as much as 45 times higher than that on alumina particles. This difference cannot be fully explained by the surface area difference between the two materials. Our titration data have demonstrated that nanoscale confinement has a significant effect, most likely via the overlap of the electric double layer (EDL), on ion sorption onto mesopore surfaces. This effect cannot be adequately modeled by existing surface complexation models, which were developed mostly for an unconfined solid-water interface. Our titration data have also indicated that the rate of ion uptake by mesoporous alumina is relatively slow, probably due to diffusion into mesopores, and complete equilibration for sorption could take 4-5 min. A molecular simulation using a density functional theory was performed to calculate ion adsorption coefficients as a function of pore size. The calculation has shown that as pore size is reduced to nanoscales (<10 nm), the adsorption coefficients of ions can vary by more than two orders of magnitude relative to those for unconfined interfaces. The prediction is supported by our experimental data on Zn sorption onto mesoporous alumina. Owing to their unique surface chemistry, mesoporous materials can potentially be used as effective ion adsorbents for separation processes and environmental cleanup.

  13. Hydrogen sulfide removal from hot coal gas by various mesoporous silica supported Mn{sub 2}O{sub 3} sorbents

    Zhang, Z.F.; Liu, B.S., E-mail: bingsiliu@tju.edu.cn; Wang, F.; Wang, W.S.; Xia, C.; Zheng, S.; Amin, R.

    2014-09-15

    Graphical abstract: - Highlights: • Mn{sub 2}O{sub 3}/KIT-1 presented the best desulfurization performance at 600–850 °C. • High sulfur capacity of Mn{sub 2}O{sub 3}/KIT-1 correlated closely with 3-D channel of KIT-1. • Desulfurization character depended strongly on framework structure of sorbents. • High steam content suppressed greatly the occurrence of sulfidation reaction. - Abstract: A series of 50 wt% Mn{sub 2}O{sub 3} sorbents was prepared using various mesoporous silica, MCM-41, HMS, and KIT-1 as support. The influence of textural parameters of mesoporous silica, especially type of channel on the desulfurization performance of Mn{sub 2}O{sub 3} sorbents was investigated at 600–850 °C using hot coal gas containing 0.33 vol.% H{sub 2}S. The fresh and used sorbents were characterized by means of N{sub 2}-adsorption, x-ray diffraction (XRD), high resolution transmission microscopy (HRTEM) and H{sub 2} temperature- programmed reduction (H{sub 2}-TPR) techniques. The results confirmed that the manganese oxide was dispersed highly in regular pore channel of the mesoporous supports due to high surface area. Compared with the Mn{sub 2}O{sub 3}/diatomite, all mesoporous silica supported Mn{sub 2}O{sub 3} sorbents exhibited high breakthrough sulfur capacity and a sharp deactivation rate after the breakthrough point. Compared to Mn{sub 2}O{sub 3}/MCM-41 and Mn{sub 2}O{sub 3}/HMS sorbent, the Mn{sub 2}O{sub 3}/KIT-1 showed better desulfurization performance because of the 3D wormhole-like channel. The high sulfur capacity of the Mn{sub 2}O{sub 3}/KIT-1 sorbent was maintained during the eight consecutive desulfurization-regeneration cycles. The Mn{sub 2}O{sub 3}/KIT-1 still presented high desulfurization activity when hot coal gas contained low steam (<5%)

  14. Matrix molecularly imprinted mesoporous sol-gel sorbent for efficient solid-phase extraction of chloramphenicol from milk.

    Samanidou, Victoria; Kehagia, Maria; Kabir, Abuzar; Furton, Kenneth G

    2016-03-31

    Highly selective and efficient chloramphenicol imprinted sol-gel silica based inorganic polymeric sorbent (sol-gel MIP) was synthesized via matrix imprinting approach for the extraction of chloramphenicol in milk. Chloramphenicol was used as the template molecule, 3-aminopropyltriethoxysilane (3-APTES) and triethoxyphenylsilane (TEPS) as the functional precursors, tetramethyl orthosilicate (TMOS) as the cross-linker, isopropanol as the solvent/porogen, and HCl as the sol-gel catalyst. Non-imprinted sol-gel polymer (sol-gel NIP) was synthesized under identical conditions in absence of template molecules for comparison purpose. Both synthesized materials were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and nitrogen adsorption porosimetry, which unambiguously confirmed their significant structural and morphological differences. The synthesized MIP and NIP materials were evaluated as sorbents for molecularly imprinted solid phase extraction (MISPE) of chloramphenicol in milk. The effect of critical extraction parameters (flow rate, elution solvent, sample and eluent volume, selectivity coefficient, retention capacity) was studied in terms of retention and desorption of chloramphenicol. Competition and cross reactivity tests have proved that sol-gel MIP sorbent possesses significantly higher specific retention and enrichment capacity for chloramphenicol compared to its non-imprinted analogue. The maximum imprinting factor (IF) was found as 9.7, whereas the highest adsorption capacity of chloramphenicol by sol-gel MIP was 23 mg/g. The sol-gel MIP was found to be adequately selective towards chloramphenicol to provide the necessary minimum required performance limit (MRPL) of 0.3 μg/kg set forth by European Commission after analysis by LC-MS even without requiring time consuming solvent evaporation and sample reconstitution step, often considered as an integral part in solid phase extraction work-flow. Intra and

  15. Synthesis of Novel Mesoporous Silica Materials with Hierarchical Pore Structures

    Yoon, Suk Bon; Choi, Wang Kyu; Choi, Byung Seon; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    Porous materials with various pore sizes in the range of micropore (< 2 nm), mesopore (2-50 nm), and macropore (> 50 nm) are attractive due to their many emerging applications such as catalysts, separation systems, and low dielectric constant materials. The discovery of new M41S mesoporous silica families with pore sizes larger than 2 nm in diameter in 1992 extended the applications into much wider pore ranges, bringing in a new prosperous era in porous material research. The synthesis of these silica materials has been mainly accomplished through a self-assembly between surfactant molecules and inorganic species under various pH conditions. Recently, core-shell nanoparticles with a silica core and mesoporous shell under basic conditions were synthesized using the silica nanoparticles as a core, and a silica precursor (TEOS) and cationic surfactant (CTABr) as a material for the formation of the mesoporous shell. The resultant materials were very monodispersive in size and showed a narrow pore size distribution in the range of ca 2-3 nm in diameter, depending on the alkyl-chain length of the surfactants used. In this work, the mesoporous shell coated-fumed silicas (denoted as MS M-5s) were synthesized by using fumed silica instead of the silica nanoparticle as a core based on previous reports. Also, the structural properties of the MS M-5s such as the specific surface area and pore volume were easily controlled by varying the amount of the silica precursor and surfactant. The resultant materials exhibited a BET surface area of ca 279-446 m{sup 2}/g and total pore volume of ca 0.64-0.74 cm{sup 3}/g and showed a narrow pore size distribution (PSD) due to the removal of the organic surfactant molecules

  16. Cumene cracking on modified mesoporous material type MCM-41

    AlMCM-41 materials, the method of its exchange mode and its grains form were investigated for the mesoporous catalytic activity in the cumene (i.e. isopropylbenzene) cracking reaction. Benzene, propylene and xylene derivatives are the main ...

  17. Evaluation of bi-functionalized mesoporous silicas as reversed phase/cation-exchange mixed-mode sorbents for multi-residue solid phase extraction of veterinary drug residues in meat samples.

    Casado, Natalia; Pérez-Quintanilla, Damián; Morante-Zarcero, Sonia; Sierra, Isabel

    2017-04-01

    A SBA-15 type mesoporous silica was synthesized and bi-functionalized with octadecylsilane (C18) or octylsilane (C8), and sulfonic acid (SO 3 - ) groups in order to obtain materials with reversed-phase/strong cation-exchange mixed-mode retention mechanism. The resulting hybrid materials (SBA-15-C18-SO 3 - and SBA-15-C8-SO 3 - ) were comprehensively characterized. They showed high surface area, high pore volume and controlled porous size. Elemental analysis of the materials revealed differences in the amount of C18 and C8. SBA-15-C18-SO 3 - contained 0.19mmol/g of C18, while SBA-15-C8-SO 3 - presented 0.54mmol/g of C8. The SO 3 - groups anchored to the silica surface of the pore walls were 0.20 and 0.09mmol/g, respectively. The bi-functionalized materials were evaluated as SPE sorbents for the multi-residue extraction of 26 veterinary drug residues in meat samples using ultra-high-performance liquid chromatography coupled to mass spectrometry detector (UHPLC-MS/MS). Different sorbent amounts (100 and 200mg) and organic solvents were tested to optimize the extraction procedure. Both silicas showed big extraction potential and were successful in the extraction of the target analytes. The mixed-mode retention mechanism was confirmed by comparing both silicas with SBA-15 mesoporous silica mono-functionalized with C18 and C8. Best results were achieved with 200mg of SBA-15-C18-SO 3 - obtaining recoveries higher than 70% for the majority of analytes. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Sorbent suppliers

    Vedder, M.

    1994-01-01

    Sorbents are used to absorb or contain spilled and leaking chemicals, oils, lubricants and other process fluids. They are commonly used around the base of machinery in industrial applications, and in remediating oil spills on land and water. Sorbents are made from biodegradable, inorganic or synthetic materials. Organic materials include corn cobs, wood pulp, paper fiber and cotton. Inorganic materials include clay, perlite, expanded silicates and expanded mica. Synthetic sorbents are made from petroleum- or plastic-based materials such as polyurethane, polyethylene or polypropylene. Sorbents are available in a variety of forms, including pads, rolls, booms, pillows and loose particulate

  19. Evaluation of silk-floss fiber and dog fur as sorbent materials for the petroleum sector

    Santos, Lucas P. dos [Universidade Federal do Parana (PGMec/UFPR), Curitiba, PR (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica; Dubiella, Juliana [Universidade Federal do Parana (DEMEC/UFPR), Curitiba, PR (Brazil). Dept. de Engenharia Mecanica. Programa Institucional de Bolsas de Iniciacao Cientifica; Perotta, Larissa [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Programa Interdisciplinar em Engenharia de Petroleo e Gas Natural; Satyanarayana, Kestur G. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Quimica; Flores-Sahagun, Thais Sydenstricker [Universidade Federal do Parana (DEMEC/UFPR), Curitiba, PR (Brazil). Dept. de Engenharia Mecanica

    2009-07-01

    In this study silk-floss and dog fur were tested as sorbent materials for oils and the results were compared with peat, a commercial sorbent. Sorption tests were carried out in dry and aqueous systems, with and without stirring for different periods of time (5-1440 min). Density, hydrophobicity, buoyancy and water uptake by the fibers of the impregnated sorbents have been determined. The use of silk-floss and dog fur was also tested in columns to purify water containing toluene, benzene, motor oil or sunflower oil. Breakthrough curves during 120 min were drawn for each material with the samples (oily water or water containing benzene or toluene) and were analyzed by ultraviolet spectroscopy. It was concluded that the silk-floss is the best sorbent material (65.3 g oil/g sorbent) followed by the dog fur (34.6 g oil/g sorbent) and peat (19.5 g oil/g sorbent), for sorption time of 1 h in dynamic condition. The efficiency of the pollutant removal from water with the use of adsorption columns was high for both materials although the use of dog fur was preferable because of the slight superiority in efficiency compared to silk-floss and also, due to the easier packing of the dog fur in the column. (author)

  20. Functionalized mesoporous silica materials for molsidomine adsorption: Thermodynamic study

    Alyoshina, Nonna A.; Parfenyuk, Elena V., E-mail: evp@iscras.ru

    2013-09-15

    A series of unmodified and organically modified mesoporous silica materials was prepared. The unmodified mesoporous silica was synthesized via sol–gel synthesis in the presence of D-glucose as pore-forming agent. The functionalized by phenyl, aminopropyl and mercaptopropyl groups silica materials were prepared via grafting. The fabricated adsorbent materials were characterized by Fourier transform infrared spectroscopy (FTIR) analysis, N{sub 2} adsorption/desorption and elemental analysis methods. Then their adsorption properties for mesoionic dug molsidomine were investigated at 290–313 K and physiological pH value. Thermodynamic parameters of molsidomine adsorption on the synthesized materials have been calculated. The obtained results showed that the adsorption process of molsidomine on the phenyl modified silica is the most quantitatively and energetically favorable. The unmodified and mercaptopropyl modified silica materials exhibit significantly higher adsorption capacities and energies for molsidomine than the aminopropyl modified sample. The effects are discussed from the viewpoint of nature of specific interactions responsible for the adsorption. - Graphical abstract: Comparative analysis of the thermodynamic characteristics of molsidomine adsorption showed that the adsorption process on mesoporous silica materials is controlled by chemical nature of surface functional groups. Molsidomine adsorption on the phenyl modified silica is the most quantitatively and energetically favorable. Taking into account ambiguous nature of mesoionic compounds, it was found that molsidomine is rather aromatic than dipolar. Display Omitted - Highlights: • Unmodified and organically modified mesoporous silica materials were prepared. • Molsidomine adsorption on the silica materials was studied. • Phenyl modified silica shows the highest adsorption capacity and favorable energy. • Molsidomine exhibits the lowest affinity to aminopropyl modified silica.

  1. Functionalized mesoporous silica materials for molsidomine adsorption: Thermodynamic study

    Alyoshina, Nonna A.; Parfenyuk, Elena V.

    2013-01-01

    A series of unmodified and organically modified mesoporous silica materials was prepared. The unmodified mesoporous silica was synthesized via sol–gel synthesis in the presence of D-glucose as pore-forming agent. The functionalized by phenyl, aminopropyl and mercaptopropyl groups silica materials were prepared via grafting. The fabricated adsorbent materials were characterized by Fourier transform infrared spectroscopy (FTIR) analysis, N 2 adsorption/desorption and elemental analysis methods. Then their adsorption properties for mesoionic dug molsidomine were investigated at 290–313 K and physiological pH value. Thermodynamic parameters of molsidomine adsorption on the synthesized materials have been calculated. The obtained results showed that the adsorption process of molsidomine on the phenyl modified silica is the most quantitatively and energetically favorable. The unmodified and mercaptopropyl modified silica materials exhibit significantly higher adsorption capacities and energies for molsidomine than the aminopropyl modified sample. The effects are discussed from the viewpoint of nature of specific interactions responsible for the adsorption. - Graphical abstract: Comparative analysis of the thermodynamic characteristics of molsidomine adsorption showed that the adsorption process on mesoporous silica materials is controlled by chemical nature of surface functional groups. Molsidomine adsorption on the phenyl modified silica is the most quantitatively and energetically favorable. Taking into account ambiguous nature of mesoionic compounds, it was found that molsidomine is rather aromatic than dipolar. Display Omitted - Highlights: • Unmodified and organically modified mesoporous silica materials were prepared. • Molsidomine adsorption on the silica materials was studied. • Phenyl modified silica shows the highest adsorption capacity and favorable energy. • Molsidomine exhibits the lowest affinity to aminopropyl modified silica

  2. Comparative study of hydrogen storage on metal doped mesoporous materials

    Carraro, P. M.; Sapag, K.; Oliva, M. I.; Eimer, G. A.

    2018-06-01

    The hydrogen adsorption capacity of mesoporous materials MCM-41 modified with Co, Fe, Ti, Mg and Ni at 77 K and 10 bar was investigated. Various techniques including XRD, N2 adsorption and DRUV-vis were employed for the materials characterization. The results showed that a low nickel loading on MCM-41 support promoted the presence of hydrogen-favorable sites, increasing the hydrogen storage capacity.

  3. Matrix molecularly imprinted mesoporous sol–gel sorbent for efficient solid-phase extraction of chloramphenicol from milk

    Samanidou, Victoria; Kehagia, Maria; Kabir, Abuzar; Furton, Kenneth G.

    2016-01-01

    Highly selective and efficient chloramphenicol imprinted sol–gel silica based inorganic polymeric sorbent (sol–gel MIP) was synthesized via matrix imprinting approach for the extraction of chloramphenicol in milk. Chloramphenicol was used as the template molecule, 3-aminopropyltriethoxysilane (3-APTES) and triethoxyphenylsilane (TEPS) as the functional precursors, tetramethyl orthosilicate (TMOS) as the cross-linker, isopropanol as the solvent/porogen, and HCl as the sol–gel catalyst. Non-imprinted sol–gel polymer (sol–gel NIP) was synthesized under identical conditions in absence of template molecules for comparison purpose. Both synthesized materials were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and nitrogen adsorption porosimetry, which unambiguously confirmed their significant structural and morphological differences. The synthesized MIP and NIP materials were evaluated as sorbents for molecularly imprinted solid phase extraction (MISPE) of chloramphenicol in milk. The effect of critical extraction parameters (flow rate, elution solvent, sample and eluent volume, selectivity coefficient, retention capacity) was studied in terms of retention and desorption of chloramphenicol. Competition and cross reactivity tests have proved that sol–gel MIP sorbent possesses significantly higher specific retention and enrichment capacity for chloramphenicol compared to its non-imprinted analogue. The maximum imprinting factor (IF) was found as 9.7, whereas the highest adsorption capacity of chloramphenicol by sol–gel MIP was 23 mg/g. The sol–gel MIP was found to be adequately selective towards chloramphenicol to provide the necessary minimum required performance limit (MRPL) of 0.3 μg/kg set forth by European Commission after analysis by LC-MS even without requiring time consuming solvent evaporation and sample reconstitution step, often considered as an integral part in solid phase extraction work

  4. Matrix molecularly imprinted mesoporous sol–gel sorbent for efficient solid-phase extraction of chloramphenicol from milk

    Samanidou, Victoria, E-mail: samanidu@chem.auth.gr [Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki (Greece); Kehagia, Maria [Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki (Greece); Kabir, Abuzar, E-mail: akabir@fiu.edu [International Forensic Research Institute, Department of Chemistry and Biochemistry, Florida International University, Miami, FL (United States); Furton, Kenneth G. [International Forensic Research Institute, Department of Chemistry and Biochemistry, Florida International University, Miami, FL (United States)

    2016-03-31

    Highly selective and efficient chloramphenicol imprinted sol–gel silica based inorganic polymeric sorbent (sol–gel MIP) was synthesized via matrix imprinting approach for the extraction of chloramphenicol in milk. Chloramphenicol was used as the template molecule, 3-aminopropyltriethoxysilane (3-APTES) and triethoxyphenylsilane (TEPS) as the functional precursors, tetramethyl orthosilicate (TMOS) as the cross-linker, isopropanol as the solvent/porogen, and HCl as the sol–gel catalyst. Non-imprinted sol–gel polymer (sol–gel NIP) was synthesized under identical conditions in absence of template molecules for comparison purpose. Both synthesized materials were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and nitrogen adsorption porosimetry, which unambiguously confirmed their significant structural and morphological differences. The synthesized MIP and NIP materials were evaluated as sorbents for molecularly imprinted solid phase extraction (MISPE) of chloramphenicol in milk. The effect of critical extraction parameters (flow rate, elution solvent, sample and eluent volume, selectivity coefficient, retention capacity) was studied in terms of retention and desorption of chloramphenicol. Competition and cross reactivity tests have proved that sol–gel MIP sorbent possesses significantly higher specific retention and enrichment capacity for chloramphenicol compared to its non-imprinted analogue. The maximum imprinting factor (IF) was found as 9.7, whereas the highest adsorption capacity of chloramphenicol by sol–gel MIP was 23 mg/g. The sol–gel MIP was found to be adequately selective towards chloramphenicol to provide the necessary minimum required performance limit (MRPL) of 0.3 μg/kg set forth by European Commission after analysis by LC-MS even without requiring time consuming solvent evaporation and sample reconstitution step, often considered as an integral part in solid phase extraction work

  5. Sorption of Aromatic Compounds with Copolymer Sorbent Materials Containing β-Cyclodextrin

    Lee D. Wilson

    2011-08-01

    Full Text Available Urethane copolymer sorbent materials that incorporate β-cyclodextrin (CD have been prepared and their sorption properties with chlorinated aromatic compounds (i.e., pentachlorophenol, 2,4-dichlorophenol and 2,4-dichlorophenoxy acetic acid have been evaluated. The sorption properties of granular activated carbon (GAC were similarly compared in aqueous solution at variable pH conditions. The sorbents displayed variable BET surface areas as follows: MDI-X copolymers (< 101 m2/g, CDI-X copolymers (< 101 m2/g, and granular activated carbon (GAC ~103 m2/g. The sorption capacities for the copolymers sorbents are listed in descending order, as follows: GAC > CDI-3 copolymer ≈ MDI-3 copolymer. The sorption capacity for the aromatic adsorbates with each sorbent are listed in descending order, as follows: 2,4-dichlorophenol > 2,4-dichlorophenoxy acetic acid > pentachlorophenol. In general, the differences in the sorption properties of the copolymer sorbents with the chlorinated organics were related to the following factors: (i surface area of the sorbent; (ii CD content and accessibility; and (iii and the chemical nature of the sorbent material.

  6. Sorption of Aromatic Compounds with Copolymer Sorbent Materials Containing β-Cyclodextrin.

    Wilson, Lee D; Mohamed, Mohamed H; Berhaut, Christopher L

    2011-08-29

    Urethane copolymer sorbent materials that incorporate β-cyclodextrin (CD) have been prepared and their sorption properties with chlorinated aromatic compounds (i.e., pentachlorophenol, 2,4-dichlorophenol and 2,4-dichlorophenoxy acetic acid) have been evaluated. The sorption properties of granular activated carbon (GAC) were similarly compared in aqueous solution at variable pH conditions. The sorbents displayed variable BET surface areas as follows: MDI-X copolymers (granular activated carbon (GAC ~10³ m²/g). The sorption capacities for the copolymers sorbents are listed in descending order, as follows: GAC > CDI-3 copolymer ≈ MDI-3 copolymer. The sorption capacity for the aromatic adsorbates with each sorbent are listed in descending order, as follows: 2,4-dichlorophenol > 2,4-dichlorophenoxy acetic acid > pentachlorophenol. In general, the differences in the sorption properties of the copolymer sorbents with the chlorinated organics were related to the following factors: (i) surface area of the sorbent; (ii) CD content and accessibility; and (iii) and the chemical nature of the sorbent material.

  7. Adsorption Of Water And Benzene Vapour In Mesoporous Materials

    Paulina Taba

    2008-11-01

    Full Text Available Mesoporous materials have attracted the attention of many researchers due to the potential applications promised by the materials. This article discusses adsorption of water and benzene vapour in mesoporous materials (mesoporous silica: MCM-41, MCM-48 and their modification. MCM-41 and MCM-48 were synthesized hydrothermally at 100 oC using cethyltrimethylammonium chloride or dodecyltrimethylammonium bromide for MCM-41 (C16 or MCM-41 (C12 respectively and a mixture of cethyltrimethylammonium bromide and Triton X-100 for MCM-48 as templates. Their modifications were conducted by silylation of MCM-41 (C16 and MCM-48 with trimethylchloro silane (MCM16-TMCS and MCM48-TMCS and t-butyldimethylchloro silane (MCM16-TBDMCS and MCM48-TBDMCS. Results showed that MCM-41 and MCM-48 materials had hydrophobic features which were shown in the small amount of water adsorption at low P/P0. The hydrophobicity of samples used in this study decrease in the sequence: MCM-41 (C16 > MCM-48 > MCM-41 (C12. The hydrophobicity increased when MCM-41 and MCM-48 were silylated with TMCS or TBDMCS. All unsilylated MCM materials show higher affinity to benzene at low P/P0 than the silylated samples. The results of water and benzene adsorption showed that silylated samples are promising candidates as selective adsorbents for organic compounds.

  8. Magnetic mesoporous material for the sequestration of algae

    Trewyn, Brian G.; Kandel, Kapil; Slowing, Igor Ivan; Lee, Show-Ling

    2014-09-09

    The present invention provides a magnetic mesoporous nanoparticle that includes a mesoporous silicate nanoparticle and iron oxide. The present invention also provides a method of using magnetic mesoporous nanoparticles to sequester microorganisms from a media.

  9. Novel sorbent materials for environmental remediation via Pyrolysis of biomass

    Zabaniotou, Anastasia

    2013-04-01

    showed the appearance of micropores to mesopores in the produced tire active carbons. Activated carbon prepared from olive kernel is a super active carbon and used as an adsorbent for the removal of pesticide from aqueous solutions (Bromopropylate). The higher removal achieved was 100% in 60 min. The produced activated carbon from agricultural residue was proved to be very effective for gas and water stream purification. Biomass can give a wide spectrum of fuels and materials in the integrated concept of biorefinery

  10. Fluorescent Functionalized Mesoporous Silica for Radioactive Material Extraction

    Li, Juan; Zhu, Kake; Shang, Jianying; Wang, Donghai; Nie, Zimin; Guo, Ruisong; Liu, Chongxuan; Wang, Zheming; Li, Xiaolin; Liu, Jun

    2012-01-01

    Mesoporous silica with covalently bound salicylic acid molecules incorporated in the structure was synthesized with a one-pot, co-condensation reaction at room temperature. The as-synthesized material has a large surface area, uniform particle size, and an ordered pore structure as determined by characterization with transmission electron microscopy, thermal gravimetric analysis, and infrared spectra, etc. Using the strong fluorescence and metal coordination capability of salicylic acid, functionalized mesoporous silica (FMS) was developed to track and extract radionuclide contaminants, such as uranyl (U(VI)) ions encountered in subsurface environments. Adsorption measurements showed a strong affinity of the FMS toward U(VI) with a Kd value of 105 mL/g, which is four orders of magnitude higher than the adsorption of U(VI) onto most of the sediments in natural environments. The new materials have a potential for synergistic environmental monitoring and remediation of the radionuclide U(VI) from contaminated subsurface environments.

  11. Sorption of Aromatic Compounds with Copolymer Sorbent Materials Containing β-Cyclodextrin

    Wilson, Lee D.; Mohamed, Mohamed H.; Berhaut, Christopher L.

    2011-01-01

    Urethane copolymer sorbent materials that incorporate β-cyclodextrin (CD) have been prepared and their sorption properties with chlorinated aromatic compounds (i.e., pentachlorophenol, 2,4-dichlorophenol and 2,4-dichlorophenoxy acetic acid) have been evaluated. The sorption properties of granular activated carbon (GAC) were similarly compared in aqueous solution at variable pH conditions. The sorbents displayed variable BET surface areas as follows: MDI-X copolymers (< 101 m2/g), CDI-X cop...

  12. A review on chemical methodologies for preparation of mesoporous silica and alumina based materials.

    Naik, Bhanudas; Ghosh, Narendra Nath

    2009-01-01

    The discovery of novel family of molecular sieves called M41S aroused a worldwide resurgence in the field of porous materials. According to IUPAC definition inorganic solids that contain pores with diameter in the size range of 20-500 A are considered mesoporous materials. Mesoporous silica and alumina based materials find applications in catalysis, adsorption, host- guest encapsulation etc. This article reviews the current state of art and outline the recent patents in mesoporous materials research in three general areas: Synthesis, various mechanisms involved for porous structure formation and applications of silica and alumina based mesoporous materials.

  13. Experimental investigation of various vegetable fibers as sorbent materials for oil spills.

    Annunciado, T R; Sydenstricker, T H D; Amico, S C

    2005-11-01

    Oil spills are a global concern due to their environmental and economical impact. Various commercial systems have been developed to control these spills, including the use of fibers as sorbents. This research investigates the use of various vegetable fibers, namely mixed leaves residues, mixed sawdust, sisal (Agave sisalana), coir fiber (Cocos nucifera), sponge-gourd (Luffa cylindrica) and silk-floss as sorbent materials of crude oil. Sorption tests with crude oil were conducted in deionized and marine water media, with and without agitation. Water uptake by the fibers was investigated by tests in dry conditions and distillation of the impregnated sorbent. The silk-floss fiber showed a very high degree of hydrophobicity and oil sorption capacity of approximately 85goil/g sorbent (in 24hours). Specific gravity measurements and buoyancy tests were also used to evaluate the suitability of these fibers for the intended application.

  14. Experimental investigation of various vegetable fibers as sorbent materials for oil spills

    Annunciado, T.R.; Sydenstricker, T.H.D.; Amico, S.C. [Federal University of Parana, Curitiba, (Brazil). Department of Mechanical Engineering

    2005-11-15

    Oil spills are a global concern due to their environmental and economical impact. various commercial systems have been developed to control these spills, including the use of fibers as sorbents. This research investigates the use of various vegetable fibers, namely mixed leaves residues, mixed sawdust, sisal (Agave sisalana), coir fiber (Cocos nucifera), sponge-gourd (Luffa cylindrica) and silk-floss as sorbent materials of crude oil. Sorption tests with crude oil were conducted in deionized and marine water media, with and without agitation. Water uptake by the fibers was investigated by tests in dry conditions and distillation of the impregnated sorbent. The silk-floss fiber showed a very high degree of hydrophobicity and oil sorption capacity of approximately 85 g oil/g sorbent (in 24 hours). Specific gravity measurements and buoyancy tests were also used to evaluate the suitability of these fibers for the intended application. (author)

  15. Mesoporous silica based MCM-41 as solid-phase extraction sorbent combined with micro-liquid chromatography-quadrupole-mass spectrometry for the analysis of pharmaceuticals in waters.

    Dahane, S; Martínez Galera, M; Marchionni, M E; Socías Viciana, M M; Derdour, A; Gil García, M D

    2016-05-15

    This paper reports the first application of the silica based mesoporous material MCM-41 as a sorbent in solid phase extraction, to pre-concentrate pharmaceuticals of very different polarity (atenolol, nadolol, pindolol, timolol, bisoprolol, metoprolol, betaxolol, ketoprofen, naproxen, ibuprofen, diclofenac, tolfenamic acid, flufenamic acid and meclofenamic acid) in surface waters. The analytes were extracted from 100mL water samples at pH 2.0 (containing 10(-3) mol/L of sodium chloride) by passing the solution through a cartridge filled with 100 mg of MCM-41. Following elution, the pharmaceuticals were determined by micro-liquid chromatography and triple quadrupole-mass spectrometry. Two selected reaction monitoring transitions were monitored per compound, the most intense one being used for quantification and the second one for confirmation. Matrix effect was found in real waters for most analytes and was overcome using the standard addition method, which compared favorably with the matrix matched calibration method. The detection limits in solvent (acetonitrile:water 10:90, v/v) ranged from 0.01 to 1.48 μg/L and in real water extracts from 0.10 to 3.85 μg/L (0.001-0.0385 μg/L in the water samples). The quantitation limits in solvent were in the range 0.02-4.93 μg/L, whereas in real water extracts were between 0.45 and 10.00 μg/L (0.0045 and 0.1000 μg/L in the water samples). When ultrapure water samples were spiked at two concentration levels of each pharmaceutical (0.1 and 0.2 μg/L) and quantified using solvent based calibration graphs, recoveries were near 100%. However, recoveries for most pharmaceuticals were comparable or better than de described above, when river water samples (spiked at the same concentration levels) were quantified by the standard addition method and slightly worse using the matrix matched calibration method. Five real samples (two rivers, one dam and two fountain water samples) were analyzed by the developed method, atenolol

  16. Actinide Sequestration Using Self-Assembled Monolayers on Mesoporous Supports

    Fryxell, Glen E.; Lin, Yuehe; Fiskum, Sandra K.; Birnbaum, Jerome C.; Wu, Hong; Kemner, K. M.; Kelly, Shelley

    2005-01-01

    Surfactant templated synthesis of mesoporous ceramics provides a versatile foundation upon which to create high efficiency environmental sorbents. These nanoporous ceramic oxides condense a huge amount of surface area into a very small volume. The ceramic oxide interface is receptive to surface functionalization through molecular self-assembly. The marriage of mesoporous ceramics with self-assembled monolayer chemistry creates a powerful new class of environmental sorbent materials called self-assembled monolayers on mesoporous supports (SAMMS). These SAMMS materials are highly efficient sorbents, whose interfacial chemistry can be fine-tuned to selectively sequester a specific target species, such as heavy metals, tetrahedral oxometallate anions and radionuclides. Details addressing the design, synthesis and characterization of SAMMS materials specifically designed to sequester actinides, of central importance to the environmental clean-up necessary after 40 years of weapons grade plutonium production, as well as evaluation of their binding affinities and kinetics are presented

  17. Removal of Heavy Metals from Aqueous Solution Using Novel Nanoengineered Sorbents: Self-Assembled Carbamoylphosphonic Acids on Mesoporous Silica

    Yantasee, Wassana; Lin, Yuehe; Fryxell, Glen E.; Busche, Brad J.; Birnbaum, Jerome C.

    2003-01-01

    Self-assembled monolayers of carbamoylphosphonic acids (acetamide phosphonic acid and propionamide phosphonic acid) on mesoporous silica supports were studied as potential absorbents for heavy and transition metal ions in aqueous wastes. The adsorption capacity, selectivity, and kinetics of the materials in sequestering metal ions, including Cd2+, Co2+, Cu2+, Cr3+, Pb2+, Ni2+, Zn2+, and Mn2+, were measured in batch experiments with excess sodium ion. The solution pH ranged from 2.2 to 5.5. The kinetics study shows that the adsorption reached equilibrium in seconds, indicating that there is little resistance to mass transfer, intraparticle diffusion, and surface chemical reaction. The competitive adsorption study found the phosphonic acid-SAMMS to have an affinity for divalent metal ions in decreasing order of Pb2+ > Cu2+ > Mn2+ > Cd2+ > Zn2+ > Co2+ > Ni2+. The measured Cd2+ adsorption isotherm was of the Langmuirian type and had a saturation binding capacity of 0.32 mmol/g

  18. Mesoporous silica as carrier of antioxidant for food packaging materials

    Buonocore, Giovanna Giuliana; Gargiulo, Nicola; Verdolotti, Letizia; Liguori, Barbara; Lavorgna, Marino; Caputo, Domenico

    2014-05-01

    Mesoporous silicas have been long recognized as very promising materials for the preparation of drug delivery systems. In this work SBA-15 mesoporous silica has been functionalized with amino-silane to be used as carrier of antioxidant compound in the preparation of active food packaging materials exhibiting tailored release properties. Active films have been prepared by loading the antioxidant tocopherol, the purely siliceous SBA-15 and the aminofunctionalized SBA-15 loaded with tocopherol into LDPE matrix trough a two-step process (mixing+extrusion). The aim of the present work is the study of the effect of the pore size and of the chemical functionality of the internal walls of the mesophase on the migration of tocopherol from active LDPE polymer films. Moreover, it has been proved that the addition of the active compound do not worsen the properties of the film such as optical characteristic and water vapor permeability, thus leading to the development of a material which could be favorably used mainly, but not exclusively, in the sector of food packaging.

  19. Mesoporous materials as fining agents in variety Cabernet Sauvignon wines

    Dumitriu Georgiana-Diana

    2016-01-01

    Full Text Available Innovative oenological products and techniques constantly need to be optimized in order to produce high quality wines that are able to fulfill the demanding consumers, with a pleasant colour, astringency, bitterness and a balanced organoleptic profile. New mesoporous materials with viability and environmental safety characteristics, might be a feasible alternative to the use of bentonite, while nowadays in the winemaking there is a major challenge caused by wastes derivate mainly from wine clarification stages. This study was aimed at investigating the influence of conventional (bentonite and activated coal and alternative (MCM-41, SBA-15, KIT-6 fining agents on enological parameters, colour, as well as on the antioxidant activity of a Cabernet Sauvignon wines. Our results show that mesoporous materials, KIT-6 and SBA-15 (6 g/L present the highest reduction on antioxidant activity with 23.08% and 24.41%, while bentonite and activated coal (1.5 g/L reduced with 20.72%, respectively 33.18%. Cluster analysis performed with the values of antioxidant activity differentiated wines treated with activated carbon from other wines.

  20. Hexamethyldisilazane Removal with Mesoporous Materials Prepared from Calcium Fluoride Sludge.

    Kao, Ching-Yang; Lin, Min-Fa; Nguyen, Nhat-Thien; Tsai, Hsiao-Hsin; Chang, Luh-Maan; Chen, Po-Han; Chang, Chang-Tang

    2018-05-01

    A large amount of calcium fluoride sludge is generated by the semiconductor industry every year. It also requires a high amount of fuel consumption using rotor concentrators and thermal oxidizers to treat VOCs. The mesoporous adsorbent prepared by calcium fluoride sludge was used for VOCs treatment. The semiconductor industry employs HMDS to promote the adhesion of photo-resistant material to oxide(s) due to the formation of silicon dioxide, which blocks porous adsorbents. The adsorption of HMDS (Hexamethyldisiloxane) was tested with mesoporous silica materials synthesized from calcium fluoride (CF-MCM). The resulting samples were characterized by XRD, XRF, FTIR, N2-adsorption-desorption techniques. The prepared samples possessed high specific surface area, large pore volume and large pore diameter. The crystal patterns of CF-MCM were similar with Mobil composite matter (MCM-41) from TEM image. The adsorption capacity of HMDS with CF-MCM was 40 and 80 mg g-1, respectively, under 100 and 500 ppm HMDS. The effects of operation parameters, such as contact time and mixture concentration, on the performance of CF-MCM were also discussed in this study.

  1. Using sorbent waste materials to enhance treatment of micro-point source effluents by constructed wetlands

    Green, Verity; Surridge, Ben; Quinton, John; Matthews, Mike

    2014-05-01

    Sorbent materials are widely used in environmental settings as a means of enhancing pollution remediation. A key area of environmental concern is that of water pollution, including the need to treat micro-point sources of wastewater pollution, such as from caravan sites or visitor centres. Constructed wetlands (CWs) represent one means for effective treatment of wastewater from small wastewater producers, in part because they are believed to be economically viable and environmentally sustainable. Constructed wetlands have the potential to remove a range of pollutants found in wastewater, including nitrogen (N), phosphorus (P), biochemical oxygen demand (BOD) and carbon (C), whilst also reducing the total suspended solids (TSS) concentration in effluents. However, there remain particular challenges for P and N removal from wastewater in CWs, as well as the sometimes limited BOD removal within these treatment systems, particularly for micro-point sources of wastewater. It has been hypothesised that the amendment of CWs with sorbent materials can enhance their potential to treat wastewater, particularly through enhancing the removal of N and P. This paper focuses on data from batch and mesocosm studies that were conducted to identify and assess sorbent materials suitable for use within CWs. The aim in using sorbent material was to enhance the combined removal of phosphate (PO4-P) and ammonium (NH4-N). The key selection criteria for the sorbent materials were that they possess effective PO4-P, NH4-N or combined pollutant removal, come from low cost and sustainable sources, have potential for reuse, for example as a fertiliser or soil conditioner, and show limited potential for re-release of adsorbed nutrients. The sorbent materials selected for testing were alum sludge from water treatment works, ochre derived from minewater treatment, biochar derived from various feedstocks, plasterboard and zeolite. The performance of the individual sorbents was assessed through

  2. A tri-continuous mesoporous material with a silica pore wall following a hexagonal minimal surface

    Han, Yu

    2009-04-06

    Ordered porous materials with unique pore structures and pore sizes in the mesoporous range (2-50nm) have many applications in catalysis, separation and drug delivery. Extensive research has resulted in mesoporous materials with one-dimensional, cage-like and bi-continuous pore structures. Three families of bi-continuous mesoporous materials have been made, with two interwoven but unconnected channels, corresponding to the liquid crystal phases used as templates. Here we report a three-dimensional hexagonal mesoporous silica, IBN-9, with a tri-continuous pore structure that is synthesized using a specially designed cationic surfactant template. IBN-9 consists of three identical continuous interpenetrating channels, which are separated by a silica wall that follows a hexagonal minimal surface. Such a tri-continuous mesostructure was predicted mathematically, but until now has not been observed in real materials. © 2009 Macmillan Publishers Limited. All rights reserved.

  3. A tri-continuous mesoporous material with a silica pore wall following a hexagonal minimal surface

    Han, Yu; Zhang, Daliang; Chng, Leng Leng; Sun, Junliang; Zhao, L. J.; Zou, Xiaodong; Ying, Jackie

    2009-01-01

    Ordered porous materials with unique pore structures and pore sizes in the mesoporous range (2-50nm) have many applications in catalysis, separation and drug delivery. Extensive research has resulted in mesoporous materials with one-dimensional, cage-like and bi-continuous pore structures. Three families of bi-continuous mesoporous materials have been made, with two interwoven but unconnected channels, corresponding to the liquid crystal phases used as templates. Here we report a three-dimensional hexagonal mesoporous silica, IBN-9, with a tri-continuous pore structure that is synthesized using a specially designed cationic surfactant template. IBN-9 consists of three identical continuous interpenetrating channels, which are separated by a silica wall that follows a hexagonal minimal surface. Such a tri-continuous mesostructure was predicted mathematically, but until now has not been observed in real materials. © 2009 Macmillan Publishers Limited. All rights reserved.

  4. Sorbent materials for rapid remediation of wash water during radiological event relief

    Jolin, William C.; Kaminski, Michael

    2016-11-01

    Procedures for removing harmful radiation from interior and exterior surfaces of homes and businesses after a nuclear or radiological disaster may generate large volumes of radiologically contaminated waste water. Rather than releasing this waste water to potentially contaminate surrounding areas, it is preferable to treat it onsite. Retention barrels are a viable option because of their simplicity in preparation and availability of possible sorbent materials. This study investigated the use of aluminosilicate clay minerals as sorbent materials to retain 137Cs, 85Sr, and 152Eu. Vermiculite strongly retained 137Cs, though other radionuclides displayed diminished affinity for the surface. Montmorillonite exhibited increased affinity to sorb 85Sr and 152Eu in the presence of higher concentrations of 137Cs. To simulate flow within retention barrels, vermiculite was mixed with sand and used in small-scale column experiments. The GoldSim contaminate fate module was used to model breakthrough and assess the feasibility of using clay minerals as sorbent materials in retention barrels. The modeled radionuclide breakthrough profiles suggest that vermiculite-sand and montmorillonite-sand filled barrels could be used for treatment of contaminated water generated from field operations.

  5. Investigation of Room Temperature Synthesis of Titanium Dioxide Nanoclusters Dispersed on Cubic MCM-48 Mesoporous Materials

    Sridhar Budhi; Chia-Ming Wu; Dan Zhao; Ranjit T. Koodali

    2015-01-01

    Titania containing cubic MCM-48 mesoporous materials were synthesized successfully at room temperature by a modified Stöber method. The integrity of the cubic mesoporous phase was retained even at relatively high loadings of titania. The TiO2-MCM-48 materials were extensively characterized by a variety of physico-chemical techniques. The physico-chemical characterization indicate that Ti4+ ions can be substituted in framework tetrahedral positions. The relative amount of Ti4+ ions in tetrahe...

  6. Feasibility Study for the Use of Green, Bio-Based, Efficient Reactive Sorbent Material to Neutralize Chemical Warfare Agents

    2012-08-02

    REPORT Feasibility study for the use of green, bio-based, efficient reactive sorbent material to neutralize chemical warfare agents 14. ABSTRACT 16...way cellulose, lignin and hemicelluloses interact as well as whole wood dissolution occurs in ILs. The present project was conducted to 1. REPORT...Feasibility study for the use of green, bio-based, efficient reactive sorbent material to neutralize chemical warfare agents Report Title ABSTRACT Over the

  7. Functionalized mesoporous materials for adsorption and release of different drug molecules: A comparative study

    Wang Gang; Otuonye, Amy N.; Blair, Elizabeth A.; Denton, Kelley; Tao Zhimin; Asefa, Tewodros

    2009-01-01

    The adsorption capacity and release properties of mesoporous materials for drug molecules can be improved by functionalizing their surfaces with judiciously chosen organic groups. Functionalized ordered mesoporous materials containing various types of organic groups via a co-condensation synthetic method from 15% organosilane and by post-grafting organosilanes onto a pre-made mesoporous silica were synthesized. Comparative studies of their adsorption and release properties for various model drug molecules were then conducted. Functional groups including 3-aminopropyl, 3-mercaptopropyl, vinyl, and secondary amine groups were used to functionalize the mesoporous materials while rhodamine 6G and ibuprofen were utilized to investigate the materials' relative adsorption and release properties. The self-assembly of the mesoporous materials was carried out in the presence of cetyltrimethylammonium bromide (CTAB) surfactant, which produced MCM-41 type materials with pore diameters of ∼2.7-3.3 nm and moderate to high surface areas up to ∼1000 m 2 /g. The different functional groups introduced into the materials dictated their adsorption capacity and release properties. While mercaptopropyl and vinyl functionalized samples showed high adsorption capacity for rhodamine 6G, amine functionalized samples exhibited higher adsorption capacity for ibuprofen. While the diffusional release of ibuprofen was fitted on the Fickian diffusion model, the release of rhodamine 6G followed Super Case-II transport model. - Graphical abstract: The adsorption capacity and release properties of mesoporous materials for various drug molecules are tuned by functionalizing the surfaces of the materials with judiciously chosen organic groups. This work reports comparative studies of the adsorption and release properties of functionalized ordered mesoporous materials containing different hydrophobic and hydrophilic groups that are synthesized via a co-condensation and post-grafting methods for

  8. Recent progress in mesoporous titania materials: adjusting morphology for innovative applications

    Juan L Vivero-Escoto, Ya-Dong Chiang, Kevin C-W Wu and Yusuke Yamauchi

    2012-01-01

    Full Text Available This review article summarizes recent developments in mesoporous titania materials, particularly in the fields of morphology control and applications. We first briefly introduce the history of mesoporous titania materials and then review several synthesis approaches. Currently, mesoporous titania nanoparticles (MTNs have attracted much attention in various fields, such as medicine, catalysis, separation and optics. Compared with bulk mesoporous titania materials, which are above a micrometer in size, nanometer-sized MTNs have additional properties, such as fast mass transport, strong adhesion to substrates and good dispersion in solution. However, it has generally been known that the successful synthesis of MTNs is very difficult owing to the rapid hydrolysis of titanium-containing precursors and the crystallization of titania upon thermal treatment. Finally, we review four emerging fields including photocatalysis, photovoltaic devices, sensing and biomedical applications of mesoporous titania materials. Because of its high surface area, controlled porous structure, suitable morphology and semiconducting behavior, mesoporous titania is expected to be used in innovative applications.

  9. A controlled release of ibuprofen by systematically tailoring the morphology of mesoporous silica materials

    Qu Fengyu; Zhu Guangshan; Lin Huiming; Zhang Weiwei; Sun Jinyu; Li Shougui; Qiu Shilun

    2006-01-01

    A series of mesoporous silica materials with similar pore sizes, different morphologies and variable pore geometries were prepared systematically. In order to control drug release, ibuprofen was employed as a model drug and the influence of morphology and pore geometry of mesoporous silica on drug release profiles was extensively studied. The mesoporous silica and drug-loaded samples were characterized by X-ray diffraction, Fourier transform IR spectroscopy, N 2 adsorption and desorption, scanning electron microscopy, and transmission electron microscopy. It was found that the drug-loading amount was directly correlated to the Brunauer-Emmett-Teller surface area, pore geometry, and pore volume; while the drug release profiles could be controlled by tailoring the morphologies of mesoporous silica carriers. - Graphical abstract: The release of ibuprofen is controlled by tailoring the morphologies of mesoporous silica. The mesoporous silica and drug-loaded samples are characterized by powder X-ray diffraction, Fourier transform IR spectroscopy, N 2 adsorption and desorption, scanning electron microscopy, and transmission electron microscopy. The drug-loading amount is directly correlated to the Brunauer-Emmett-Teller surface area, pore geometry, and pore volume; while the drug release profiles can be controlled by tailoring the morphologies of mesoporous silica carriers

  10. A highly efficient and selective polysilsesquioxane sorbent for heavy metal removal

    Duan, Xiaonan; Qi, Genggeng; Wang, Peng; Giannelis, Emmanuel P.

    2012-01-01

    Suited for heavy stuff: An efficient mesoporous sorbent based on a pure ethylendiamine-bridged polysilsesquioxane is presented. This material, with both a high amine loading and a high surface area, is applied for heavy metal ion removal. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. A highly efficient and selective polysilsesquioxane sorbent for heavy metal removal

    Duan, Xiaonan

    2012-02-29

    Suited for heavy stuff: An efficient mesoporous sorbent based on a pure ethylendiamine-bridged polysilsesquioxane is presented. This material, with both a high amine loading and a high surface area, is applied for heavy metal ion removal. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Comparative DNA isolation behaviours of silica and polymer based sorbents in batch fashion: monodisperse silica microspheres with bimodal pore size distribution as a new sorbent for DNA isolation.

    Günal, Gülçin; Kip, Çiğdem; Eda Öğüt, S; İlhan, Hasan; Kibar, Güneş; Tuncel, Ali

    2018-02-01

    Monodisperse silica microspheres with bimodal pore-size distribution were proposed as a high performance sorbent for DNA isolation in batch fashion under equilibrium conditions. The proposed sorbent including both macroporous and mesoporous compartments was synthesized 5.1 μm in-size, by a "staged shape templated hydrolysis and condensation method". Hydrophilic polymer based sorbents were also obtained in the form of monodisperse-macroporous microspheres ca 5.5 μm in size, with different functionalities, by a developed "multi-stage microsuspension copolymerization" technique. The batch DNA isolation performance of proposed material was comparatively investigated using polymer based sorbents with similar morphologies. Among all sorbents tried, the best DNA isolation performance was achieved with the monodisperse silica microspheres with bimodal pore size distribution. The collocation of interconnected mesoporous and macroporous compartments within the monodisperse silica microspheres provided a high surface area and reduced the intraparticular mass transfer resistance and made easier both the adsorption and desorption of DNA. Among the polymer based sorbents, higher DNA isolation yields were achieved with the monodisperse-macroporous polymer microspheres carrying trimethoxysilyl and quaternary ammonium functionalities. However, batch DNA isolation performances of polymer based sorbents were significantly lower with respect to the silica microspheres.

  13. Application of a hybrid ordered mesoporous silica as sorbent for solid-phase multi-residue extraction of veterinary drugs in meat by ultra-high-performance liquid chromatography coupled to ion-trap tandem mass spectrometry.

    Casado, Natalia; Morante-Zarcero, Sonia; Pérez-Quintanilla, Damián; Sierra, Isabel

    2016-08-12

    A quick, sensitive and selective analytical reversed-phase multi-residue method using ultra-high performance liquid chromatography coupled to an ion-trap mass spectrometry detector (UHPLC-IT-MS/MS) operating in both positive and negative ion mode was developed for the simultaneous determination of 23 veterinary drug residues (β-blockers, β-agonists and Non-Steroidal Anti-inflammatory Drugs (NSAIDs)) in meat samples. The sample treatment involved a liquid-solid extraction followed by a solid-phase extraction (SPE) procedure. SBA-15 type mesoporous silica was synthetized and modified with octadecylsilane, and the resulting hybrid material (denoted as SBA-15-C18) was applied and evaluated as SPE sorbent in the purification of samples. The materials were comprehensively characterized, and they showed a high surface area, high pore volume and a homogeneous distribution of the pores. Chromatographic conditions and extraction procedure were optimized, and the method was validated according to the Commission Decision 2002/657/EC. The method detection limits (MDLs) and the method quantification limits (MQLs) were determined for all the analytes in meat samples and found to range between 0.01-18.75μg/kg and 0.02-62.50μg/kg, respectively. Recoveries for 15 of the target analytes ranged from 71 to 98%. In addition, for comparative purpose SBA-15-C18 was evaluated towards commercial C18 amorphous silica. Results revealed that SBA-15-C18 was clearly more successful in the multi-residue extraction of the 23 mentioned analytes with higher recovery values. The method was successfully tested to analyze prepacked preparations of mince bovine meat. Traces of propranolol, ketoprofen and diclofenac were detected in some samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Preparation of mesoporous carbon/polypyrrole composite materials and their supercapacitive properties

    WU-JUN ZOU

    2011-08-01

    Full Text Available We synthesized mesoporous carbons/polypyrrole composites, using a chemical oxidative polymerization and calcium carbonate as a sacrificial template. N2 adsorption-desorption method, Fourier infrared spectroscopy, and transmission electron microscopy were used to characterize the structure and morphology of the composites. The measurement results indicated that as-synthesized carbon with the disordered mesoporous structure and a pore size of approximately 5 nm was uniformly coated by polypyrrole. The electrochemical behavior of the resulting composite was examined by cyclic voltammetry and cycle life measurements, and the obtained results showed that the specific capacitance of the resulting composite electrode was as high as 313 F g−1, nearly twice the capacitance of pure mesoporous carbon electrode (163 F g–1. This reveals that the electrochemical performance of these materials is governed by a combination of the electric double layer capacitance of mesoporous carbon and pseudocapacitance of polypyrrole.

  15. Facile synthesis of a boronate affinity sorbent from mesoporous nanomagnetic polyhedral oligomeric silsesquioxanes composite and its application for enrichment of catecholamines in human urine

    He, Haibo, E-mail: hbhe2006@shu.edu.cn [Department of Chemistry, Shanghai University, Shanghai 200444 (China); Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072 (China); Zhou, Ziqing; Dong, Chen; Wang, Xin [Department of Chemistry, Shanghai University, Shanghai 200444 (China); Yu, Qiong-wei [Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072 (China); Lei, Yunyi; Luo, Liqiang [Department of Chemistry, Shanghai University, Shanghai 200444 (China); Feng, Yuqi [Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072 (China)

    2016-11-09

    A boronate-decorated nanomagnetic organic-inorganic hybrid material was facilely synthesized by utilizing the nanomagnetic polyhedral oligomeric silsesquioxanes (POSS) composite (Fe{sub 3}O{sub 4}@POSS) as the base platform. A simple copolymerization occurred between 3-acrylamidophenylboronic acid (AAPBA) and the residual end vinyl groups supplied by the substrate. Here the special emphasis was placed on the octavinyl POSS, which not only acted as the building blocks for a hybrid architecture but also facilitated the process of grafting boronate groups onto the surface of POSS based nanomagnetic composite (Fe{sub 3}O{sub 4}@POSS). The successful immobilization of affinity ligand-AAPBA on the Fe{sub 3}O{sub 4}@POSS was confirmed by Fourier transform infrared (FT-IR), elemental analysis, inductively coupled plasma atomic emission spectrometer (ICP-AES), field emission scanning electron microscope. A magnetic solid-phase extraction (MSPE) for cis-diols enrichment was developed using the as-prepared Fe{sub 3}O{sub 4}@POSS-AAPBA material as an affinity sorbent and three catecholamines (CAs), namely noradrenaline, epinephrine and isoprenaline, as model analytes. Under the optimal extraction conditions, sensitive and simultaneous analysis of three CAs from the urine sample was achieved by high-performance liquid chromatography with UV detection (HPLC-UV). The limits of detection (LOD, S/N = 3) and the limits of quantitation (LOQ, S/N = 10) for the target analytes were 0.81–1.32 ng mL{sup −1} and 2.70–4.40 ng mL{sup −1}, respectively. Also good recoveries (85.5–101.7%) and repeatability (RSD≤10.1%) were obtained by this method. This work not only showed a facility for the utilization of Fe{sub 3}O{sub 4}@POSS as a substrate for constructing a boronate functionalized nanomagnetic sorbent, but also demonstrated the capability of the derived material for recognition of trace amount of cis-diols biomolecules presented in complicated biological matrices

  16. F- and H-Area Seepage Basins Water Treatment System Process Optimization and Alternative Chemistry Ion Exchange/Sorbent Material Screening Clearwell Overflow Study

    Serkiz, S.M.

    2000-08-30

    This study investigated alternative ion exchange/sorbent materials and polishing chemistries designed to remove specific radionuclides not removed during the neutralization/precipitation/clarification process.

  17. Study of inorganic sorbents as materials for underground repositories in China

    Zhixiong, W.

    1989-01-01

    Since 1983, the construction of nuclear power plants has been taking place in Zhejiang and Guangdong provinces of China. The project is a part of the radwaste disposal plan of China. The project under the contract with IAEA studies absorption kinetics and mechanism of backfill material and selection of proper backfill material for the radwaste disposal plan. There are varieties of clay minerals as inorganic sorbents in China, such as zeolite, illite montomorillonite, kolinite, and so on. Bentonite is the first selected material for the research project. Bentonite is a common montonorillonite clay with good mechanical properties and chemical stability under certain conditions in a repository capacity. There are many huge bentonite deposits in China. China's LILW disposal will be possibly selected in the bentonite district. The investigation of China's bentonite will include the properties of China's sites, the study of migration of radionuclides and the geochemistry of actinides elements. Various bentonites of China have been studied to select one of good quality. The project is significant to assess the barrier ability of bentonite. The project also made the primary work for zeolite as a sorbent which has been used for the disposal of LILW liquid in China. Clinopliotite has been used in China's hydraulic fracture test of the radwaste liquid

  18. Mesoporous material grafted with luminescent molecules for the design of selective metal ion chemosensor

    Zhang Huidong; Zhang Ping; Ye Kaiqi; Sun Yinghui; Jiang Shimei; Wang Yue; Pang Wenqin

    2006-01-01

    Luminescent Schiff-base groups have been successfully grafted on the surface of mesoporous material MCM-48. The grafted Schiff-base groups were employed to prepare luminescent Schiff-base-Zn complex that was covalently bound to the MCM-48 surface. These luminescent mesoporous materials were characterized with X-ray, UV-VIS and emission spectroscopic methods. Experimental results demonstrated that MCM-48 modified with functional groups exhibited novel luminescent property. The chemosensing property of modified MCM-48 sample was investigated. It was demonstrated that the fluorescence of MCM-48 solid with Schiff-base groups could be completely quenched by Cu 2+ cation and this mesoporous material was suitable for sensing Cu 2+ cation in aqueous media

  19. A novel, efficient and facile method for the template removal from mesoporous materials

    Chen, Lu

    2014-11-12

    © 2014, Jilin University, The Editorial Department of Chemical Research in Chinese Universities and Springer-Verlag GmbH. A new catalytic-oxidation method was adopted to remove the templates from SBA-15 and MCM-41 mesoporous materials via Fenton-like techniques under microwave irradiation. The mesoporous silica materials were treated with different Fenton agents based on the template’s property and textural property. The samples were characterized by powder X-ray diffraction(XRD) measurement, N2 adsorption-desorption isotherms, infrared spectroscopy, 29Si MAS NMR and thermo gravimetric analysis(TGA). The results reveal that this is an efficient and facile approach to the thorough template-removal from mesoporous silica materials, as well as to offering products with more stable structures, higher BET surface areas, larger pore volumes and larger quantity of silanol groups.

  20. Facile route for synthesis of mesoporous Cr2O3 sheet as anode materials for Li-ion batteries

    Cao, Zhiqin; Qin, Mingli; Jia, Baorui; Zhang, Lin; Wan, Qi; Wang, Mingshan; Volinsky, Alex A.; Qu, Xuanhui

    2014-01-01

    Mesoporous Cr 2 O 3 with a high specific surface area of 162 m 2 g −1 is prepared by the solution combustion method. The mesoporous Cr 2 O 3 has a sheet structure, which consists of nanoparticles with an average size of 20 nm. As an anode electrode material for rechargeable lithium-ion batteries, the mesoporous Cr 2 O 3 nanoparticles display enhanced electrochemical performance. Stable and reversible capacity of 480 mA h g −1 after 55 cycles is demonstrated. The enhanced electrochemical performance of the Cr 2 O 3 can be attributed to the high surface area and morphological characteristics of mesoporous materials

  1. A Preliminary Study of Biodegradable Waste as Sorbent Material for Oil-Spill Cleanup

    Idris, J.; Eyu, G. D.; Mansor, A. M.; Ahmad, Z.; Chukwuekezie, C. S.

    2014-01-01

    Oil spill constitutes a major source of fresh and seawater pollution as a result of accidental discharge from tankers, marine engines, and underwater pipes. Therefore, the need for cost-effective and environmental friendly sorbent materials for oil spill cleanup cannot be overemphasized. The present work focuses on the preliminary study of empty palm fruit bunch fibre as a promising sorbent material. The morphology of the unmodified empty palm fruit bunch, EPFB fibre, was examined using an optical microcopy, scanning electron microcopy coupled with EDX and X-ray diffraction. The effects of oil volume, fibre weight, and time on oil absorption of EPFB fibre were evaluated with new engine oil from the model oil. The results show that EPFB fibre consists of numerous micro pores, hydrophobic, and partially crystalline and amorphous with approximately 13.5% carbon. The oil absorbency of the fibre increased with the increase in oil volume, immersion time, and fibre weight. However, sorption capacity decreased beyond 3 g in 100 mL. Additionally unmodified EPFB fibre showed optimum oil sorption efficiency of approximately 2.8 g/g within three days of immersion time. PMID:24693241

  2. New sorbent materials for selective extraction of cocaine and benzoylecgonine from human urine samples.

    Bujak, Renata; Gadzała-Kopciuch, Renata; Nowaczyk, Alicja; Raczak-Gutknecht, Joanna; Kordalewska, Marta; Struck-Lewicka, Wiktoria; Waszczuk-Jankowska, Małgorzata; Tomczak, Ewa; Kaliszan, Michał; Buszewski, Bogusław; Markuszewski, Michał J

    2016-02-20

    An increase in cocaine consumption has been observed in Europe during the last decade. Benzoylecgonine, as a main urinary metabolite of cocaine in human, is so far the most reliable marker of cocaine consumption. Determination of cocaine and its metabolite in complex biological samples as urine or blood, requires efficient and selective sample pretreatment. In this preliminary study, the newly synthesized sorbent materials were proposed for selective extraction of cocaine and benzoylecgonine from urine samples. Application of these sorbent media allowed to determine cocaine and benzoylecgonine in urine samples at the concentration level of 100ng/ml with good recovery values as 81.7%±6.6 and 73.8%±4.2, respectively. The newly synthesized materials provided efficient, inexpensive and selective extraction of both cocaine and benzoylecgonine from urine samples, which can consequently lead to an increase of the sensitivity of the current available screening diagnostic tests. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Unexpected nitrile formation in bio-based mesoporous materials (Starbons®).

    Attard, Jennifer; Milescu, Roxana; Budarin, Vitaliy; Matharu, Avtar S; Clark, James H

    2018-01-16

    The bio-based mesoporous materials made from polysaccharides, Starbons® can be modified by two different routes to give high levels of N-content, unexpectedly including significant quantities of nitrile groups which can improve the materials performance in applications including metal capture.

  4. Formation of Micro and Mesoporous Amorphous Silica-Based Materials from Single Source Precursors

    Mohd Nazri Mohd Sokri

    2016-03-01

    Full Text Available Polysilazanes functionalized with alkoxy groups were designed and synthesized as single source precursors for fabrication of micro and mesoporous amorphous silica-based materials. The pyrolytic behaviors during the polymer to ceramic conversion were studied by the simultaneous thermogravimetry-mass spectrometry (TG-MS analysis. The porosity of the resulting ceramics was characterized by the N2 adsorption/desorption isotherm measurements. The Fourier transform infrared spectroscopy (FT-IR and Raman spectroscopic analyses as well as elemental composition analysis were performed on the polymer-derived amorphous silica-based materials, and the role of the alkoxy group as a sacrificial template for the micro and mesopore formations was discussed from a viewpoint to establish novel micro and mesoporous structure controlling technologies through the polymer-derived ceramics (PDCs route.

  5. Performance of LiCl Impregnated Mesoporous Material Coating over Corrugated Heat Exchangers in a Solid Sorption Chiller

    Hongzhi Liu

    2018-06-01

    Full Text Available The composite material made by impregnating 40 wt. % lithium chloride (LiCl into the mesopores of a kind of natural porous rock (Wakkanai Siliceous Shale: WSS micropowders (short for “WSS + 40 wt. % LiCl” had been developed previously, and can be regenerated below 100 °C with a cooling coefficient of performance (COP of approximately 0.3 when adopted as a sorbent in a sorption cooler. In this study, experiments have been carried out on an intermittent solid sorption chiller with the WSS + 40 wt. % LiCl coating over two aluminum corrugated heat exchangers. Based on the experimental condition (regeneration temperature of 80 °C, condensation temperature of 30 °C in the desorption process; sorption temperature of 30 °C and evaporation temperature of 12 °C in the sorption process, the water sorption amount changes from 20 wt. % to 70 wt. % in one sorption cooling cycle. Moreover, a specific cooling power (SCP of 86 W/kg, a volumetric specific cooling power (VSCP of 42 W/dm3, and a specific sorption power of 170 W/kg can be achieved with a total sorption and desorption time of 20 min. The obtained cooling COP is approximately 0.16.

  6. Study of Horseradish Peroxidase Fixed on Mesoporous Materials as a Chemical Reaction Catalyst

    Gao, Mengdan; Dai, Rongji

    2017-12-01

    Nanostructured mesoporous materials is a new type of porous materials, which has been widely used. It has excellent capability in enzymes immobilization, but modification on the chemical bonds of the enzyme reduce the enzymatic activity and rarely used in chemical reactions. The horseradish peroxidase was immobilized on the mesoporous materials with appropriate aperture and its activity and stability was evaluated when catalyzing the nitration reaction of amines and oxidation reaction of thiourea. The optimum mesoporous material to fix the horseradish peroxidase can be obtained by mixing polyoxyethylene - polyoxypropylene-pol, yoxyethylene(P123), 1,3,5-trimethylbenzene(TMB), and tetramethoxysilane (TMOS) at a ratio of 10:1:1, whose surface area and pore volume and pore diameter calculated by BET and BJH model were 402.903m2/g, 1.084cm2/g, 1.084cm2/g respectively. The horseradish peroxidase, immobilized on the mesoporous materials, was applied for catalyzing the nitration reaction of anilines and oxidation reaction of thiourea, produced a high product yield and can be recycled. Thus, it is a strong candidate as a catalysts for oxidation reactions, to be produced at industral scale, due to its high efficiency and low cost.

  7. Importance of Micropore-Mesopore Interfaces in Carbon Dioxide Capture by Carbon-Based Materials.

    Durá, Gema; Budarin, Vitaliy L; Castro-Osma, José A; Shuttleworth, Peter S; Quek, Sophie C Z; Clark, James H; North, Michael

    2016-08-01

    Mesoporous carbonaceous materials (Starbons®) derived from low-value/waste bio-resources separate CO2 from CO2 /N2 mixtures. Compared to Norit activated charcoal (AC), Starbons® have much lower microporosities (8-32 % versus 73 %) yet adsorb up to 65 % more CO2 . The presence of interconnected micropores and mesopores is responsible for the enhanced CO2 adsorption. The Starbons® also showed three-four times higher selectivity for CO2 adsorption rather than N2 adsorption compared to AC. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Carbon-coated mesoporous SnO2 nanospheres as anode material for lithium ion batteries

    Wang, Fei; Song, Xiaoping; Yao, Gang; Zhao, Mingshu; Liu, Rui; Xu, Minwei; Sun, Zhanbo

    2012-01-01

    In this paper mesoporous SnO 2 nanospheres with an average diameter of about 83 nm, composed of many tiny primary particles (∼10 nm) and holes, are synthesized on a large scale by a simple hydrothermal route. The as-prepared mesoporous SnO 2 nanospheres were uniformly coated with carbon by a further hydrothermal treatment in glucose aqueous solution. As anode materials for lithium-ion batteries, the core–shell SnO 2 /C nanocomposites exhibit a markedly improved cycling performance.

  9. A novel, efficient and facile method for the template removal from mesoporous materials

    Chen, Lu; Jiang, Shang; Wang, Runwei; Zhang, Zongtao; Qiu, Shilun

    2014-01-01

    © 2014, Jilin University, The Editorial Department of Chemical Research in Chinese Universities and Springer-Verlag GmbH. A new catalytic-oxidation method was adopted to remove the templates from SBA-15 and MCM-41 mesoporous materials via Fenton

  10. Oxidative dehydrogenation of ethane over vanadium supported on mesoporous materials of M41S family

    Čapek, J.; Adam, J.; Grygar, Tomáš; Bulánek, R.; Vradman, L.; Košová-Kučerová, G.; Čičmanec, P.; Knotek, P.

    2008-01-01

    Roč. 342, 1-2 (2008), s. 99-106 ISSN 0926-860X Grant - others:GA ČR(CZ) GP104/07/P038 Program:GP Institutional research plan: CEZ:AV0Z40320502 Keywords : oxidative dehydrogenation * ethane * vanadium * mesoporous materials Subject RIV: CA - Inorganic Chemistry Impact factor: 3.190, year: 2008

  11. Validity of the t-plot method to assess microporosity in hierarchical micro/mesoporous materials.

    Galarneau, Anne; Villemot, François; Rodriguez, Jeremy; Fajula, François; Coasne, Benoit

    2014-11-11

    The t-plot method is a well-known technique which allows determining the micro- and/or mesoporous volumes and the specific surface area of a sample by comparison with a reference adsorption isotherm of a nonporous material having the same surface chemistry. In this paper, the validity of the t-plot method is discussed in the case of hierarchical porous materials exhibiting both micro- and mesoporosities. Different hierarchical zeolites with MCM-41 type ordered mesoporosity are prepared using pseudomorphic transformation. For comparison, we also consider simple mechanical mixtures of microporous and mesoporous materials. We first show an intrinsic failure of the t-plot method; this method does not describe the fact that, for a given surface chemistry and pressure, the thickness of the film adsorbed in micropores or small mesopores (plot method to estimate the micro- and mesoporous volumes of hierarchical samples is then discussed, and an abacus is given to correct the underestimated microporous volume by the t-plot method.

  12. (18)O(2) label mechanism of sulfur generation and characterization in properties over mesoporous Sm-based sorbents for hot coal gas desulfurization.

    Liu, B S; Wan, Z Y; Wang, F; Zhan, Y P; Tian, M; Cheung, A S C

    2014-02-28

    Using a sol-gel method, SmMeOx/MCM-41 or SBA-15 (Me=Fe, Co and Zn) and corresponding unsupported sorbents were prepared. The desulfurization performance of these sorbents was evaluated over a fixed-bed reactor and the effects of reaction temperature, feed and sorbent composition on desulfurization performance were studied. Samarium-based sorbents used to remove H2S from hot coal gas were reported for the first time. The results of successive sulfidation/regeneration cycles revealed that SmFeO3/SBA-15 sorbent was suitable for desulfurization of hot coal gas in the chemical industry. The formation of elemental sulfur during both sulfidation and regeneration processes depended strongly on the catalytic action of Sm2O2S species, which was confirmed for the first time via high sensitive time of flight mass spectrometer (TOF-MS) using 6%vol(18)O2/Ar regeneration gas and can reduce markedly procedural complexity. The sorbents were characterized using N2-adsorption, high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), temperature-programmed reduction of H2 (H2-TPR), thermogravimetry (TG) and time-of-flight mass spectrometry (TOF-MS) techniques. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Influence of metal loading on hydrocracking of rapeseed oil using bifunctional micro-/mesoporous composite materials

    Gille, T.; Busse, O.; Reschetilowski, W. [Technische Univ. Dresden (Germany). Inst. of Industrial Chemistry

    2013-11-01

    Hydrocracking of rapeseed oil has been investigated in a fixed bed reactor under integral conditions. A synthesized micro-/mesoporous composite material Al-MCM-41/ZSM-5 modified by different metal loadings (NiMo, PtNiMo, Pt) was used as catalyst system. It could be demonstrated that the support material and their metal loading influence the product selectivity as well as the deactivation tendencies of the catalyst sample. (orig.)

  14. Nanocasting of Periodic Mesoporous Materials as an Effective Strategy to Prepare Mixed Phases of Titania

    Luther Mahoney

    2015-12-01

    Full Text Available Mesoporous titanium dioxide materials were prepared using a nanocasting technique involving silica SBA-15 as the hard-template. At an optimal loading of titanium precursor, the hexagonal periodic array of pores in SBA-15 was retained. The phases of titanium dioxide could be easily varied by the number of impregnation cycles and the nature of titanium alkoxide employed. Low number of impregnation cycles produced mixed phases of anatase and TiO2(B. The mesoporous TiO2 materials were tested for solar hydrogen production, and the material consisting of 98% anatase and 2% TiO2(B exhibited the highest yield of hydrogen from the photocatalytic splitting of water. The periodicity of the pores was an important factor that influenced the photocatalytic activity. This study indicates that mixed phases of titania containing ordered array of pores can be prepared by using the nanocasting strategy.

  15. Controlled synthesis of the tricontinuous mesoporous material IBN-9 and its carbon and platinum derivatives

    Zhao, Yunfeng

    2011-08-23

    Controlled synthesis of mesoporous materials with ultracomplicated pore configurations is of great importance for both fundamental research of nanostructures and the development of novel applications. IBN-9, which is the only tricontinuous mesoporous silica with three sets of interpenetrating three-dimensional channel systems, appears to be an excellent model mesophase for such study. The extensive study of synthesis space diagrams proves mesophase transition among the cylindrical MCM-41, tricontinuous IBN-9 and bicontinuous MCM-48, and also allows a more precise control of phase-pure synthesis. On the other hand, rational design of structure-directing agents offers a possibility to extend the synthesis conditions of IBN-9, as well as tailor its pore size. Moreover, an unprecedented helical structure consisting of twisted 3-fold interwoven mesoporous channels is reported here for the first time. The unique tricontinuous mesostructure of IBN-9 has been well-replicated by other functional materials (e.g., carbon and platinum) via a "hard- templating" synthesis route. The obtained carbon material possesses large surface area (∼1900 m2/g), high pore volume (1.56 cm 3/g), and remarkable gas adsorption capability at both cryogenic temperatures and room temperature. The platinum material has an ordered mesostructure composed of highly oriented nanocrystals. © 2011 American Chemical Society.

  16. The carbonaceous sorbent based on the secondary silica-containing material from oil extraction industry

    Starostina, I. V.; Stolyarov, D. V.; Anichina, Ya N.; Porozhnyuk, E. V.

    2018-01-01

    The object of research in this work is the silica-containing waste of oil extraction industry - the waste kieselghur (diatomite) sludge from precoat filtering units, used for the purification of vegetable oils from organic impurities. As a result of the thermal modification of the sludge, which contains up to 70% of organic impurities, a finely-dispersed low-porous carbonaceous mineral sorption material is formed. The modification of the sludge particles surface causes the substantial alteration of its physical, chemical, adsorption and structural properties - the organic matter is charred, the particle size is reduced, and on the surface of diatomite particles a carbon layer is formed, which deposits in macropores and partially occludes them. The amount of mesopores is increased, along with the specific surface of the obtained product. The optimal temperature of sludge modification is 500°C. The synthesized carbonaceous material can be used as an adsorbing agent for the purification of wastewater from heavy metal ions. The sorption capacity of Cu2+ ions amounted to 14.2 mg·g-1 and for Ni2+ ions - 17.0 mg·g-1. The obtained values exceed the sorption capacity values of the initial kieselghur, used as a filtering charge, for the researched metal ions.

  17. Nanocomposite of cobalt oxide and ordered mesoporous carbon as the electrode materials for supercapacitor

    Xu, J.; Liu, P.; Zhao, J.; Feng, J.; Tang, B. [Shanghai Univ. of Engineering Science (China). College of Chemistry and Chemical Engineering

    2010-07-01

    An incipient wetness impregnation method was used to prepare a cobalt oxide ordered mesoporous carbon composite for use as an electrode in supercapacitor applications. The composite was then incorporated inside periodic nanoholes in the ordered mesoporous carbon (OMC). X-ray diffraction (XRD), transmission electron microscopy (TEM) and N{sub 2} adsorption-desorption isotherm analyses were used to characterize the structures of the samples. The specific capacitance of the synthesized materials was estimated using cyclic voltammetric (CV) analyses. The study showed that composites prepared using the new method exhibited a higher reversible specific capacitance of 594.8 F per g at a scan rate of 5 mV per second. The composite also showed good cyclic stability. Results suggested that the composite can be used as an electrode material in supercapacitors.

  18. Selective Preparation of trans-Carveol over Ceria Supported Mesoporous Materials MCM-41 and SBA-15

    Nariman F. Salakhutdinov

    2013-05-01

    Full Text Available Ce-modified mesoporous silica materials MCM-41 and SBA-15, namely 32 wt % Ce–Si–MCM-41, 16 wt % Ce–H–MCM-41 and 20 wt % Ce–Si–SBA-15, were prepared, characterized and studied in the selective preparation of trans-carveol by α-pinene oxide isomerization. The characterizations of these catalysts were performed using scanning electron microscopy, X-ray photoelectron spectroscopy, nitrogen adsorption and FTIR pyridine adsorption. Selective preparation of trans-carveol was carried out in the liquid phase in a batch reactor. The activity and the selectivity of catalyst were observed to be influenced by their acidity, basicity and morphology of the mesoporous materials. The formation of trans-carveol is moreover strongly influenced by the basicity of the used solvent and in order to achieve high yields of this desired alcohol it is necessary to use polar basic solvent.

  19. Cooperation of micro- and meso-porous carbon electrode materials in electric double-layer capacitors

    Zheng, Cheng [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, Jilin Province (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Qi, Li; Wang, Hongyu [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, Jilin Province (China); Yoshio, Masaki [Advanced Research Center, Saga University, 1341 Yoga-machi, Saga 840-0047 (Japan)

    2010-07-01

    The capacitive characteristics of micro- and meso-porous carbon materials have been compared in cyclic voltammetric studies and galvanostatic charge-discharge tests. Meso-porous carbon can keep certain high capacitance values at high scan rates, whereas micro-porous carbon possesses very high capacitance values at low scan rates but fades quickly as the scan rate rises up. For better performance of electric double-layer capacitors (EDLCs), the cooperative application of both kinds of carbon materials has been proposed in the following two ways: mixing both kinds of carbons in the same electrode or using the asymmetric configuration of carbon electrodes in the same EDLC. The cooperative effect on the electrochemical performance has also been addressed. (author)

  20. Composite materials based on inorganic sorbents and extractants - new sorbents for several radionuclides removal from liquid radioactive wastes

    Kopyrin, A.A.

    1999-01-01

    A short review of recent investigation concerned with liquid radioactive waste treatment by means of composite materials. It is considered different aspects of technology of selective radionuclides removal and its direction connected with usage of composites. Results of research works in this line carried out under the direction of author are presented. (author)

  1. Hydrocracking of ethyl laurate on bifunctional micro-/mesoporous composite materials

    Adam, M.; Busse, O.; Reschetilowski, W. [Technische Univ. Dresden (Germany). Inst. for Industrial Chemistry

    2011-07-01

    Hydrocracking of ethyl laurate (dodecanoic acid ethyl ester) as a representative model compound of vegetable oil has been investigated in a fixed bed reactor under integral conditions. A synthesized micro-/mesoporous composite support material Al-MCM-41/ZSM-5 modified by different metal loadings (NiMo, NiW, PtNiW) was used as catalyst system. It could be demonstrated that the metal loading and reducibility influence product selectivity as well as deactivation behavior of catalyst samples. (orig.)

  2. Mesoporous CuO–ZnO binary metal oxide nanocomposite for decontamination of sulfur mustard

    Praveen Kumar, J.; Prasad, G.K.; Ramacharyulu, P.V.R.K.; Garg, P.; Ganesan, K.

    2013-01-01

    Mesoporous CuO–ZnO binary metal oxide nanocomposites were studied as sorbent decontaminants against sulfur mustard, a well known chemical warfare agent. They were prepared by precipitation pyrolysis method and characterized by means of X-ray diffraction, transmission electron microscopy, nitrogen adsorption, Fourier transform infrared spectroscopy techniques. Obtained data indicated the presence of mesopores with diameter ranging from 2 to 80 nm and the materials exhibited relatively high surface area 86 m 2 g −1 when compared to the individual metal oxide nanoparticles. Reactive sites of mesoporous CuO–ZnO binary metal oxide nanocomposites were studied by infrared spectroscopy technique using pyridine as a probe molecule. These materials demonstrated superior decontamination properties against sulfur mustard when compared to single component metal oxides and decontaminated it to divinyl sulfide, chloroethyl vinyl sulfide, hemisulfur mustard, etc. - Graphical abstract: Mesoporous CuO–ZnO binary metal oxide nanocomposites were studied as sorbent decontaminants against sulfur mustard, a well known chemical warfare agent. These materials demonstrated superior decontamination properties against sulfur mustard and decontaminated it to divinyl sulfide, chloroethyl vinyl sulfide, hemisulfur mustard, etc. - Highlights: • Preparation of mesoporous CuO–ZnO binary metal oxide nanocomposite. • CuO–ZnO with better surface area was synthesized by precipitation pyrolysis. • Decontamination of HD using mesoporous CuO–ZnO binary metal oxide nanocomposite. • HD decontaminated by elimination and hydrolysis reactions

  3. Mesoporous CuO–ZnO binary metal oxide nanocomposite for decontamination of sulfur mustard

    Praveen Kumar, J.; Prasad, G.K., E-mail: gkprasad2001@yahoo.com; Ramacharyulu, P.V.R.K.; Garg, P.; Ganesan, K.

    2013-11-01

    Mesoporous CuO–ZnO binary metal oxide nanocomposites were studied as sorbent decontaminants against sulfur mustard, a well known chemical warfare agent. They were prepared by precipitation pyrolysis method and characterized by means of X-ray diffraction, transmission electron microscopy, nitrogen adsorption, Fourier transform infrared spectroscopy techniques. Obtained data indicated the presence of mesopores with diameter ranging from 2 to 80 nm and the materials exhibited relatively high surface area 86 m{sup 2} g{sup −1} when compared to the individual metal oxide nanoparticles. Reactive sites of mesoporous CuO–ZnO binary metal oxide nanocomposites were studied by infrared spectroscopy technique using pyridine as a probe molecule. These materials demonstrated superior decontamination properties against sulfur mustard when compared to single component metal oxides and decontaminated it to divinyl sulfide, chloroethyl vinyl sulfide, hemisulfur mustard, etc. - Graphical abstract: Mesoporous CuO–ZnO binary metal oxide nanocomposites were studied as sorbent decontaminants against sulfur mustard, a well known chemical warfare agent. These materials demonstrated superior decontamination properties against sulfur mustard and decontaminated it to divinyl sulfide, chloroethyl vinyl sulfide, hemisulfur mustard, etc. - Highlights: • Preparation of mesoporous CuO–ZnO binary metal oxide nanocomposite. • CuO–ZnO with better surface area was synthesized by precipitation pyrolysis. • Decontamination of HD using mesoporous CuO–ZnO binary metal oxide nanocomposite. • HD decontaminated by elimination and hydrolysis reactions.

  4. Aerogel sorbents

    Begag, Redouane; Rhine, Wendell E.; Dong, Wenting

    2018-04-03

    The current invention describes methods and compositions of various sorbents based on aerogels of various silanes and their use as sorbent for carbon dioxide. Methods further provide for optimizing the compositions to increase the stability of the sorbents for prolonged use as carbon dioxide capture matrices.

  5. Functionalisation of mesoporous materials for application as additives in high temperature PEM fuel cell membranes

    Sharifi, Monir

    2012-03-06

    The presented thesis contains six original research articles dedicated to the preparation and characterization of organic-inorganic mesoporous materials as additives for polymer electroly1e membrane fuel cells (PEMFCs). The mesoporous materials Si-MCM-41 and benzene-PMO (periodic mesoporous organosilica) were chosen for the investigations. These materials were modified with functional groups for enhanced proton conductivity and water-keeping properties. In order to improve these materials Broenstedt acidic groups were introduced in the framework of mesoporous Si-MCM-41. Therefore, some silicium atoms in the framework were substituted by aluminium using different aluminium sources. Here NaAlO{sub 2} exhibits clearly the best results because the entire aluminium incorporated within the framework is tetragonally coordinated as observed by {sup 2}7AI MAS NMR. The increase of the proton conductivities results from an improved hydrophilicity, a decreased particle size, and newly introduced Broenstedt acidity in the mesoporous Al-MCM-41. However, mesoporous Si-MCM-41 materials functionalised by co-condensation with sulphonic acid groups exhibit the best results concerning proton conductivity, compared to those prepared by grafting. Hence, these materials where characterized in more detail by SANS and by MAS NMR measurements. The first one indicated that by co-condensation the entire inner pore surface is altered by functional groups which are, thus, distributed much more homogeneously than samples functionalised by grafting. This result explains the improved proton conductivities. Additionally, {sup 2}9Si NMR spectra proved that samples prepared by co-condensation lead to a successful and almost complete incorporation of mercaptopropyltrimethoxysilan (MPMS) into the mesoporous framework. Furthermore, it was shown by {sup 1}3C MAS NMR spectroscopy that the majority of the organic functional groups remained intact after H{sub 2}0{sub 2}-oxidation. However, proton

  6. Design of engineered sorbent barriers

    Jones, E.O.; Freeman, H.D.

    1988-08-01

    A sorbent barrier uses sorbent material such as activated carbon or natural zeolites to prevent the migration of radionuclides from a low-level waste site to the aquifer. The sorbent barrier retards the movement of radioactive contaminants, thereby providing time for the radionuclides to decay. Sorbent barriers can be a simple, effective, and inexpensive method for reducing the migration of radionuclides to the environment. Designing a sorbent barrier consists of using soil and sorbent material properties and site conditions as input to a model which will determine the necessary sorbent barrier thickness to meet contaminant limits. The paper will cover the following areas: techniques for measuring sorption properties of barrier materials and underlying soils, use of a radionuclide transport model to determine the required barrier thickness and performance under a variety of site conditions, and cost estimates for applying the barrier. 8 refs., 6 figs., 1 tab

  7. Design of engineered sorbent barriers

    Jones, E.O.; Freeman, H.D.

    1988-01-01

    A sorbent barrier uses sorbent material such as activated carbon or natural zeolites to prevent the migration of radionuclides from a low-level waste site to the aquifer. The sorbent barrier retards the movement of radioactive contaminants, thereby providing time for the radionuclides to decay. Sorbent barriers can be a simple, effective, and inexpensive method for reducing the migration of radionuclides to the environment. Designing a sorbent barrier consists of using soil and sorbent material properties and site conditions as input to a model which will determine the necessary sorbent barrier thickness to meet contaminant limits. The paper covers the following areas: techniques for measuring sorption properties of barrier materials and underlying soils, use of a radionuclide transport model to determine the required barrier thickness and performance under a variety of site conditions, and cost estimates for applying the barrier

  8. Steam-assisted crystallization of TPA+-exchanged MCM-41 type mesoporous materials with thick pore walls

    Chen, Hong Li; Zhang, Kun; Wang, Yi Meng

    2012-01-01

    Highlights: ► Mesoporous Ti-containing silica with thicker pore walls was synthesized. ► Ion-exchange and steam-assisted crystallization led to MCM-41/MFI composite. ► The introduction of Ti inhibited the formation of separated MFI particles. ► Lower temperature favored retaining mesoporous characteristics and morphology. -- Abstract: Hierarchical MCM-41/MFI composites were synthesized through ion-exchange of as-made MCM-41 type mesoporous materials with tetrapropylammonium bromide and subsequent steam-assisted recrystallization. The obtained samples were characterized by powder X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis, FT-IR, 1 H– 13 C CP/MAS and nitrogen adsorption–desorption. The XRD patterns show that the MCM-41/MFI composite possesses both ordered MCM-41 phase and zeolite MFI phase. SEM and TEM images indicate that the recrystallized materials retained the mesoporous characteristics and the morphology of as-made mesoporous materials without the formation of bulky zeolite, quite different from the mechanical mixture of MCM-41 and MFI structured zeolite. Among others, lower recrystallization temperature and the introduction of the titanium to the parent materials are beneficial to preserve the mesoporous structure during the recrystallization process.

  9. Selective Preparation of Furfural from Xylose over Sulfonic Acid Functionalized Mesoporous Sba-15 Materials

    Panpan Li

    2011-04-01

    Full Text Available Sulfonic acid functionalized mesoporous SBA-15 materials were prepared using the co-condensation and grafting methods, respectively, and their catalytic performance in the dehydration of xylose to furfural was examined. SBA-15-SO3H(C prepared by the co-condensation method showed 92–95% xylose conversion and 74% furfural selectivity, and 68–70% furfural yield under the given reaction conditions. The deactivation and regeneration of the SBA-15-SO3H(C catalyst for the dehydration of xylose was also investigated. The results indicate that the used and regeneration catalysts retained the SBA-15 mesoporous structure, and the S content of SBA-15-SO3H(C almost did not change. The deactivation of the catalysts is proposed to be associated with the accumulation of byproducts, which is caused by the loss reaction of furfural. After regeneration by H2O2, the catalytic activity of the catalyst almost recovered.

  10. Hydrodeoxygenation of Pyrolysis Bio-Oil Over Ni Impregnated Mesoporous Materials.

    Lee, In-Gu; Lee, Heejin; Kang, Bo Sung; Kim, Young-Min; Kim, Sang Chai; Jung, Sang-Chul; Ko, Chang Hyun; Park, Young-Kwon

    2018-02-01

    The catalytic hydrodeoxygenation (HDO) of bio-oil over Ni-supported mesoporous materials was performed using a high pressure autoclave reactor. The actual pyrolysis oil of cork oak wood was used as a sample, and Ni/Al-SBA-15 and Ni/Al-MSU-F were used as catalysts. In addition, supercritical ethanol was added as solvent. Both Ni-supported mesoporous catalysts showed efficient HDO reaction ability. A higher heating value and pH of bio-oil were achieved by the HDO reaction over both catalysts and upgraded bio-oil had a lower viscosity. Compared to Ni/Al-MSU-F, Ni/Al- SBA-15 produced more upgraded bio-oil with a lower oxygen content and higher heating value via a catalytic HDO process.

  11. Hierarchically mesoporous silica materials prepared from the uniaxially stretched polypropylene membrane and surfactant templates

    Wang Xiaocong; Ma Jin; Liu Jin; Zhou Chen; Zhao, Yan; Yi Shouzhi; Yang Zhenzhong

    2006-01-01

    Hierarchically mesoporous silica materials with a bimodal distribution were template-prepared from uniaxially stretched polypropylene membrane in the presence of a surfactant via a sol-gel process. Their regularity and morphologies were characterized by transmission electron microscopy (TEM), x-ray diffraction and Brunauer-Emmett-Teller (BET) surface area analysis. The larger channel pores formed by removing the microfibrils of uniaxially stretched polypropylene membrane have a broad pore size distribution, and their size is around 13 nm. In contrast, the smaller mesopores formed by surfactant templates have a narrow distribution; their size is about 3.9 nm. The size of the smaller pores could be tuned from 2 to 6 nm by selecting different surfactants and by changing the concentration of reactants

  12. Optical oxygen sensing materials based on a novel dirhenium(I) complex assembled in mesoporous silica

    Liu Yanhong; Li Bin; Cong Yan; Zhang Liming; Fan Di; Shi Linfang

    2011-01-01

    A new dirhenium(I) complex fac-[{Re(CO) 3 (4,7-dinonadecyl-1,10-phenanthro -line)} 2 (4,4'-bipyridyl)] (trifluoromethanesulfonate) 2 (denoted as D-Re(I) ) is assembled in MCM-41 and SBA-15 type mesoporous silica support. The emission peaks of D-Re(I) in D-Re(I)/MCM-41 and D-Re(I)/SBA-15 are observed at 522 and 517 nm, respectively. Their long excited lifetimes, which are of the order of microseconds, indicate the presence of phosphorescence emission arising from the metal to ligand charge-transfer (MLCT) transition. The luminescence intensities of D-Re(I)/MCM-41 and D-Re(I)/SBA-15 decrease remarkably with increase in the oxygen concentration, meaning that they can be used as optical oxygen sensing materials based on luminescence quenching. The ratios I 0 /I 100 of D-Re(I)/MCM-41 and D-Re(I)/SBA-15 are estimated to be 5.6 and 20.1, respectively. The obtained Stern-Volmer oxygen quenching plots of the mesoporous sensing materials could be fitted well to the two-site Demas model and Lehrer model. - Research highlights: → Dirhenium(I) complex assembled in mesoporous molecular sieves for oxygen sensor design. → Large α-diimine ligand L used to improve oxygen sensing properties. → High sensitivity (I 0 /I 100 ) up to 20.1.

  13. Amorphous Mn oxide-ordered mesoporous carbon hybrids as a high performance electrode material for supercapacitors.

    Nam, Inho; Kim, Nam Dong; Kim, Gil-Pyo; Park, Junsu; Yi, Jongheop

    2012-07-01

    A supercapacitor has the advantages of both the conventional capacitors and the rechargeable batteries. Mn oxide is generally recognized one of the potential materials that can be used for a supercapacitor, but its low conductivity is a limiting factor for electrode materials. In this study, a hybrid of amorphous Mn oxide (AMO) and ordered mesoporous carbon (OMC) was prepared and characterized using X-ray diffraction, transmission electron microscopy, N2/77 K sorption techniques, and electrochemical analyses. The findings indicate that the electrochemical activities of Mn oxide were facilitated when it was in the hybrid state because OMC acted as a pathway for both the electrolyte ions and the electrons due to the characteristics of the ordered mesoporous structure. The ordered mesoporous structure of OMC was well maintained even after hybridization with amorphous Mn oxide. The electrochemical-activity tests revealed that the AMO/OMC hybrid had a higher specific capacitance and conductivity than pure Mn oxide. In the case where the Mn/C weight ratio was 0.75, the composite showed a high capacitance of 153 F/g, which was much higher than that for pure Mn oxide, due to the structural effects of OMC.

  14. Construction of order mesoporous (Eu–La)/ZnO composite material and its luminescent characters

    Bao, Na; Liu, Yu; Li, Zi-Wei [School of Chemistry & Environmental Engineering, Changchun University of Science and Technology, Changchun 130022 (China); Yu, Hui, E-mail: yh2001101@163.com [School of Chemistry & Environmental Engineering, Changchun University of Science and Technology, Changchun 130022 (China); Bai, Hao-tian [School of Chemistry & Environmental Engineering, Changchun University of Science and Technology, Changchun 130022 (China); Xia, Long, E-mail: xialong_aron@163.com [School of Materials Science and Engineering, Harbin Institute of Technology at Weihai, Weihai 264209 (China); Feng, Da-wei [Changchun University of Science and Technology Science Park, Changchun 130022 (China); Guangdong College of Business and Technology, Zhaoqing 526020 (China); Zhang, Hong-bo; Dong, Xiang-ting; Wang, Tian-yang; Han, Ji; Wu, Rong-yi; Zhang, Qi [School of Chemistry & Environmental Engineering, Changchun University of Science and Technology, Changchun 130022 (China)

    2016-09-15

    For the first time, the order mesoporous zinc oxide was synthesized by a soft template synthesis method. The Eu and La phosphate were introduced into the prepared mesoporous zinc oxide by the high temperature solid phase method, and got the mesoporous rare earth/zinc oxide composite materials. The luminescence characters of the materials were studied. The influences of La to Eu luminescent properties had been studied, and the optimum proportion of Eu and La was discussed. The influences of La and Eu to ZnO luminescence properties were also been studied. La phosphate had the large influence to Eu luminescent. ZnO had a strong emission peak at 469 nm, which overlapped with the {sup 7}F{sub 0}–{sup 5}D{sub 2} transition excitation peak of Eu at 465 nm. It indicated that the effective energy transfer happened between ZnO and Eu, which strongly enhanced the luminescence intensity of Eu. At the same time, the Eu and La phosphates could regulate the defect density of ZnO, which could regulate the luminescent intensity of ZnO, and realized the adjustment of luminescent color between green and red light.

  15. Waste Derived Sorbents and Their Potential Roles in Heavy Metal Remediation Applications

    Chiang Y. W.

    2013-04-01

    Full Text Available Inorganic waste materials that have the suitable inherent characteristics could be used as precursors for the synthesis of micro- and mesoporous materials, which present great potential to be re-utilized as sorbent materials for heavy metal remediation. Three inorganic waste materials were studied in the present work: water treatment residuals (WTRs from an integrated drinking water/wastewater treatment plant, and fly ash and bottom ash samples from a municipal solid waste incinerator (MSWI. These wastes were converted into three sorbent materials: ferrihydrite-like materials derived from drying of WTRs, hydroxyapatite-like material derived from ultrasound assisted synthesis of MSWI fly ash with phosphoric acid solution, and a zeolitic material derived from alkaline hydrothermal conversion of MSWI bottom ash. The performance of these materials, as well as their equivalent commercially available counterparts, was assessed for the adsorption of multiple heavy metals (As, Cd, Co, Ni, Pb, Zn from synthetic solutions, contaminated sediments and surface waters; and satisfactory results were obtained. In addition, it was observed that the combination of sorbents into sorbent mixtures enhanced the performance levels and, where applicable, stabilized inherently mobile contaminants from the waste derived sorbents.

  16. Enantioselectively controlled release of chiral drug (metoprolol) using chiral mesoporous silica materials

    Guo Zhen; Liu Xianbin; Ng, Siu-Choon; Chen Yuan; Yang Yanhui; Du Yu

    2010-01-01

    Chiral porous materials have attracted burgeoning attention on account of their potential applications in many areas, such as enantioseparation, chiral catalysis, chemical sensors and drug delivery. In this report, chiral mesoporous silica (CMS) materials with various pore sizes and structures were prepared using conventional achiral templates (other than chiral surfactant) and a chiral cobalt complex as co-template. The synthesized CMS materials were characterized by x-ray diffraction, nitrogen physisorption, scanning electron microscope and transmission electron microscope. These CMS materials, as carriers, were demonstrated to be able to control the enantioselective release of a representative chiral drug (metoprolol). The release kinetics, as modeled by the power law equation, suggested that the release profiles of metoprolol were remarkably dependent on the pore diameter and pore structure of CMS materials. More importantly, R- and S-enantiomers of metoprolol exhibited different release kinetics on CMS compared to the corresponding achiral mesoporous silica (ACMS), attributable to the existence of local chirality on the pore wall surface of CMS materials. The chirality of CMS materials on a molecular level was further substantiated by vibrational circular dichroism measurements.

  17. Enantioselectively controlled release of chiral drug (metoprolol) using chiral mesoporous silica materials

    Guo Zhen; Liu Xianbin; Ng, Siu-Choon; Chen Yuan; Yang Yanhui [School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459 (Singapore); Du Yu, E-mail: du_yu@jlu.edu.cn, E-mail: yhyang@ntu.edu.sg [College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China)

    2010-04-23

    Chiral porous materials have attracted burgeoning attention on account of their potential applications in many areas, such as enantioseparation, chiral catalysis, chemical sensors and drug delivery. In this report, chiral mesoporous silica (CMS) materials with various pore sizes and structures were prepared using conventional achiral templates (other than chiral surfactant) and a chiral cobalt complex as co-template. The synthesized CMS materials were characterized by x-ray diffraction, nitrogen physisorption, scanning electron microscope and transmission electron microscope. These CMS materials, as carriers, were demonstrated to be able to control the enantioselective release of a representative chiral drug (metoprolol). The release kinetics, as modeled by the power law equation, suggested that the release profiles of metoprolol were remarkably dependent on the pore diameter and pore structure of CMS materials. More importantly, R- and S-enantiomers of metoprolol exhibited different release kinetics on CMS compared to the corresponding achiral mesoporous silica (ACMS), attributable to the existence of local chirality on the pore wall surface of CMS materials. The chirality of CMS materials on a molecular level was further substantiated by vibrational circular dichroism measurements.

  18. Polyaniline nanofiber/large mesoporous carbon composites as electrode materials for supercapacitors

    Liu, Huan; Xu, Bin; Jia, Mengqiu, E-mail: jiamq@mail.buct.edu.cn; Zhang, Mei; Cao, Bin; Zhao, Xiaonan; Wang, Yu

    2015-03-30

    Highlights: • The composites of polyaniline nanofiber and large mesoporous carbon were prepared for supercapacitors. • The large mesoporous carbons were simply prepared by nano-CaCO{sub 3} template method. • The composites exhibit high capacitance and good rate capability and cycle stability. - Abstract: A composite of polyaniline nanofiber/large mesoporous carbon (PANI-F/LMC) hybrid was prepared by an in situ chemical oxidative polymerization of aniline monomer with nano-CaCO{sub 3} templated LMC as host matrix for supercapacitors. The morphology, composition and electronic structure of the composites (PANI-F/LMC) together with pure PANI nanofibers and the LMC were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), FT-IR, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It is found that the PANI nanofibers were incorporated into the large mesochannels of LMC with interpenetrating framework formed. Such unique structure endows the PANI-F/LMC composite with a high capacitance of 473 F g{sup −1} at a current load of 0.1 A g{sup −1} with good rate performance and cycling stability, suggesting its potential application in the electrode material for supercapacitors.

  19. Polyaniline nanofiber/large mesoporous carbon composites as electrode materials for supercapacitors

    Liu, Huan; Xu, Bin; Jia, Mengqiu; Zhang, Mei; Cao, Bin; Zhao, Xiaonan; Wang, Yu

    2015-01-01

    Highlights: • The composites of polyaniline nanofiber and large mesoporous carbon were prepared for supercapacitors. • The large mesoporous carbons were simply prepared by nano-CaCO 3 template method. • The composites exhibit high capacitance and good rate capability and cycle stability. - Abstract: A composite of polyaniline nanofiber/large mesoporous carbon (PANI-F/LMC) hybrid was prepared by an in situ chemical oxidative polymerization of aniline monomer with nano-CaCO 3 templated LMC as host matrix for supercapacitors. The morphology, composition and electronic structure of the composites (PANI-F/LMC) together with pure PANI nanofibers and the LMC were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), FT-IR, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It is found that the PANI nanofibers were incorporated into the large mesochannels of LMC with interpenetrating framework formed. Such unique structure endows the PANI-F/LMC composite with a high capacitance of 473 F g −1 at a current load of 0.1 A g −1 with good rate performance and cycling stability, suggesting its potential application in the electrode material for supercapacitors

  20. Assessment of surface acidity in mesoporous materials containing aluminum and titanium

    Araújo, Rinaldo S.; Maia, Débora A. S.; Azevedo, Diana C. S.; Cavalcante, Célio L., Jr.; Rodríguez-Castellón, E.; Jimenez-Lopez, A.

    2009-04-01

    The surface acidity of mesoporous molecular sieves of aluminum and titanium was evaluated using four different techniques: n-butylamine volumetry, cyclohexylamine thermodesorption, temperature-programmed desorption of ammonia and adsorption of pyridine. The nature, strength and concentration of the acid sites were determined and correlated to the results of a probe reaction of anthracene oxidation to 9,10-anthraquinone (in liquid phase). In general, the surface acidity was highly influenced by the nature, location and coordination of the metal species (Al and Ti) in the mesoporous samples. Moderate to strong Brönsted acid sites were identified for the Al-MCM-41 sample in a large temperature range. For mesoporous materials containing Ti, the acidity was represented by a combination of weak to moderate Brönsted and Lewis acid sites. The Ti-HMS sample exhibits a higher acidity of moderate strength together with a well-balanced concentration of Brönsted and Lewis acid sites, which enhanced both conversion and selectivity in the oxidation reaction of anthracene.

  1. Fenton detemplation of ordered (meso)porous materials

    Melian-Cabrera, I.; Osman, A. H.; van Eck, E. R. H.; Kentgens, Arno P.M.; Polushkin, E.; Kapteijn, F.; Moulijn, J. A.; Xu, R; Gao, Z; Chen, J; Yan, W

    2007-01-01

    This article describes a new methodology (Fenton detemplation), which consists of removing the template by chemical oxidation and develop the material's porosity. The oxidizing agents are OH radicals, which are generated from H(2)O(2) in the presence of catalytic amounts of Fe cations. This is known

  2. Mercury removal sorbents

    Alptekin, Gokhan

    2016-03-29

    Sorbents and methods of using them for removing mercury from flue gases over a wide range of temperatures are disclosed. Sorbent materials of this invention comprise oxy- or hydroxyl-halogen (chlorides and bromides) of manganese, copper and calcium as the active phase for Hg.sup.0 oxidation, and are dispersed on a high surface porous supports. In addition to the powder activated carbons (PACs), this support material can be comprised of commercial ceramic supports such as silica (SiO.sub.2), alumina (Al.sub.2O.sub.3), zeolites and clays. The support material may also comprise of oxides of various metals such as iron, manganese, and calcium. The non-carbon sorbents of the invention can be easily injected into the flue gas and recovered in the Particulate Control Device (PCD) along with the fly ash without altering the properties of the by-product fly ash enabling its use as a cement additive. Sorbent materials of this invention effectively remove both elemental and oxidized forms of mercury from flue gases and can be used at elevated temperatures. The sorbent combines an oxidation catalyst and a sorbent in the same particle to both oxidize the mercury and then immobilize it.

  3. Soft templating strategies for the synthesis of mesoporous materials: inorganic, organic-inorganic hybrid and purely organic solids.

    Pal, Nabanita; Bhaumik, Asim

    2013-03-01

    With the discovery of MCM-41 by Mobil researchers in 1992 the journey of the research on mesoporous materials started and in the 21st century this area of scientific investigation have extended into numerous branches, many of which contribute significantly in emerging areas like catalysis, energy, environment and biomedical research. As a consequence thousands of publications came out in large varieties of national and international journals. In this review, we have tried to summarize the published works on various synthetic pathways and formation mechanisms of different mesoporous materials viz. inorganic, organic-inorganic hybrid and purely organic solids via soft templating pathways. Generation of nanoscale porosity in a solid material usually requires participation of organic template (more specifically surfactants and their supramolecular assemblies) called structure-directing agent (SDA) in the bottom-up chemical reaction process. Different techniques employed for the syntheses of inorganic mesoporous solids, like silicas, metal doped silicas, transition and non-transition metal oxides, mixed oxides, metallophosphates, organic-inorganic hybrids as well as purely organic mesoporous materials like carbons, polymers etc. using surfactants are depicted schematically and elaborately in this paper. Moreover, some of the frontline applications of these mesoporous solids, which are directly related to their functionality, composition and surface properties are discussed at the appropriate places. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Synthesis and characterization of mesoporous Mn-MCM-41 materials

    Saladino, Maria Luisa; Kraleva, Elka; Todorova, Silvia; Spinella, Alberto; Nasillo, Giorgio; Caponetti, Eugenio

    2011-01-01

    Highlights: · Manganese MCM-41 as catalyst. · Influence of pH on the structure of MCM-41. · Influence of manganese on the structure and activity of Mn-MCM-41. - Abstract: MCM-41 has been synthesized at two different pH using cetyl-trimethylammonium bromide (CTAB) surfactant as template and adding the silica precursor to aqueous solutions containing CTAB. The obtained solids were calcined at 600 deg. C for 4 h. Mn-MCM-41 powders with different Mn/Si molar ratios were prepared using the incipient wetness method, followed by calcination at 550 deg. C for 5 h. At the end of the impregnation process the powders colour changed from white to brown whose intensity depends on manganese quantity. The materials characterization was performed by X-ray diffraction, N 2 adsorption, 29 Si Cross Polarization-Magic Angle Spinning NMR, and X-ray Photoelectron Spectroscopy. The effects of the manganese quantity and of the structural characteristic of the MCM-41 support were studied. The catalytic activity of the prepared systems was evaluated in a complete n-hexane oxidation.

  5. In vitro catheter and sorbent-based method for clearance of radiocontrast material during cerebral interventions

    Angheloiu, George O.; Hänscheid, Heribert; Reiners, Christoph; Anderson, William D.; Kellum, John A.

    2013-01-01

    Background: Contrast-induced acute kidney injury is a severe condition resulting from the use of radiology contrast in patients with predisposing factors. Hypothesis: We hypothesized that a novel system including a device containing polymer resin sorbent beads and a custom-made suctioning catheter could efficiently remove contrast from an in vitro novel model of circulatory system (MOCS) mimicking the cerebral circulation. Methods: A custom-made catheter was built and optimized for cerebral venous approach. The efficiency of a system made of a polymer resin sorbent beads column (CST 401, Cytosorbents) and this particular catheter was tested in the MOCS running a solution composed of 0.9% saline and radio-contrast. During two series of 18 cycles of first-pass experiments we assessed the catheter's suctioning efficiency and the system's ability to clear radio-contrast injected into the MOCS's cerebral arterial segment. We also assessed the functioning and reliability of the MOCS. Results: Mean suctioning efficiency of the catheter was 84% ± 24%. The polymer sorbent column contrast removal rate was initially 96% and gradually decreased with subsequent cycles in a linear fashion during an experiment lasting approximately 90 minutes. The MOCS had a reliability of 0.9946×min −1 where 1 × min −1 was the optimum value. Conclusion: A system including a polymer resin sorbent beads column and a custom-made suctioning catheter had an excellent initial efficiency in quickly removing contrast from an artificial MOCS mimicking the cerebral circulation. MOCS is an inexpensive and relatively reliable custom-made system that can be used for training or testing purposes

  6. In vitro catheter and sorbent-based method for clearance of radiocontrast material during cerebral interventions

    Angheloiu, George O., E-mail: goangheloiu@drmc.org [Heart and Vascular Institute, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Department of Cardiology, Dubois Regional Medical Center, Dubois, PA (United States); Hänscheid, Heribert; Reiners, Christoph [Department of Nuclear Medicine, University of Würzburg, Würzburg (Germany); Anderson, William D. [Cardiology Department, Exempla Healthcare, Denver, CO (United States); Kellum, John A. [CRISMA Center, Department of Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA (United States)

    2013-07-15

    Background: Contrast-induced acute kidney injury is a severe condition resulting from the use of radiology contrast in patients with predisposing factors. Hypothesis: We hypothesized that a novel system including a device containing polymer resin sorbent beads and a custom-made suctioning catheter could efficiently remove contrast from an in vitro novel model of circulatory system (MOCS) mimicking the cerebral circulation. Methods: A custom-made catheter was built and optimized for cerebral venous approach. The efficiency of a system made of a polymer resin sorbent beads column (CST 401, Cytosorbents) and this particular catheter was tested in the MOCS running a solution composed of 0.9% saline and radio-contrast. During two series of 18 cycles of first-pass experiments we assessed the catheter's suctioning efficiency and the system's ability to clear radio-contrast injected into the MOCS's cerebral arterial segment. We also assessed the functioning and reliability of the MOCS. Results: Mean suctioning efficiency of the catheter was 84% ± 24%. The polymer sorbent column contrast removal rate was initially 96% and gradually decreased with subsequent cycles in a linear fashion during an experiment lasting approximately 90 minutes. The MOCS had a reliability of 0.9946×min{sup −1} where 1 × min{sup −1} was the optimum value. Conclusion: A system including a polymer resin sorbent beads column and a custom-made suctioning catheter had an excellent initial efficiency in quickly removing contrast from an artificial MOCS mimicking the cerebral circulation. MOCS is an inexpensive and relatively reliable custom-made system that can be used for training or testing purposes.

  7. A new nano-sorbent for fast and efficient removal of heavy metals from aqueous solutions based on modification of magnetic mesoporous silica nanospheres

    Vojoudi, Hossein; Badiei, Alireza; Bahar, Shahriyar; Mohammadi Ziarani, Ghodsi; Faridbod, Farnoush; Ganjali, Mohammad Reza

    2017-11-01

    In the present study, a new and efficient nanosorbent for the fast removal of heavy metal ions was prepared. The proposed nanosorbent was fabricated using Fe3O4 magnetic core shelled by mesoporous silica, and cetyltrimethylammonium bromide (CTAB) as surfactant template through a sol-gel process. The magnetic nanomaterial was further modified with bis(3-triethoxysilylpropyl)tetrasulfide (MSCMNPs-S4). The final nanosphers were characterized by FT-IR, XRD, TGA, BET, SEM, TEM, DLS, VSM, EDX, and UV-Vis. The potential of the resultant mesoporous magnetite nanomaterials was investigated as a convenient and effective adsorbent for the removal of toxic heavy metal ions from aqueous solutions in a batch system. The effect of essential parameters on the removal efficiency including initial pH of sample solution, adsorbent amount, metal ion concentration, contact time and type and quantity of the eluent on the adsorption characteristics of the MSCMNPs-S4 were studied. Under the optimized conditions, the proposed nanosorbent exhibited high adsorption capacity of 303.03, 256.41 and 270.27 mg g-1 and maximum removal percentages of 98.8%, 96.4%, 95.7% for Hg(II), Pd(II) and Pb(II) ions, respectively. The mechanism of the adsorbtion was found to be in good agreement with the Langmuir isotherm model. Furthermore, the reusability investigation indicated that the MSCMNPs-S4 could be used frequently at least for five cycles without any significant loss in its performance.

  8. Investigating the Effects of Loading Factors on the In Vitro Pharmaceutical Performance of Mesoporous Materials as Drug Carriers for Ibuprofen

    Junmin Lai

    2017-02-01

    Full Text Available The aim of the study was to investigate the effects of the loading factors, i.e., the initial drug loading concentration and the ratio of the drug to carriers, on the in vitro pharmaceutical performance of drug-loaded mesoporous systems. Ibuprofen (IBU was used as a model drug, and two non-ordered mesoporous materials of commercial silica Syloid® 244FP (S244FP and Neusilin® US2 (NS2 were selected in the study. The IBU-loaded mesoporous samples were prepared by a solvent immersion method with a rotary evaporation drying technique and characterized by polarized light microscopy (PLM, Fourier transform infrared (FTIR spectroscopy, X-ray powder diffraction (XRPD and differential scanning calorimetry (DSC. Dissolution experiments were performed in simulated gastric media at 37 °C under non-sink conditions. The concentration of IBU in solution was determined by HPLC. The study showed that the dissolution rate of IBU can be improved significantly using the mesoporous S224FP carriers due to the conversion of crystalline IBU into the amorphous form. Both of the loading factors affected the IBU dissolution kinetics. Due to the molecular interaction between the IBU and NS2 carriers, the loading factors had little effects on the drug release kinetics with incomplete drug desorption recovery and insignificant dissolution enhancement. Care and extensive evaluation must therefore be taken when mesoporous materials are chosen as carrier delivery systems.

  9. Mesoporous LiMnPO4/C nanoparticles as high performance cathode material for lithium ion batteries

    Wen, Fang; Shu, Hongbo; Zhang, Yuanyuan; Wan, Jiajia; Huang, Weihua; Yang, Xiukang; Yu, Ruizhi; Liu, Li; Wang, Xianyou

    2016-01-01

    LiMnPO 4 has been considered as one of the most promising high voltage cathode materials for next-generation lithium ion batteries. However, LiMnPO 4 suffers from intrinsic drawbacks of extremely low electronic conductivity and ionic diffusivity between LiMnPO 4 /MnPO 4 . In this paper, mesoporous LiMnPO 4 nanoparticles are synthesized successfully via a facile glycine-assisted solvothermal rout. The as-prepared mesoporous LiMnPO 4 /C nanoparticles present well-defined abundant mesoporous structure (diameter of 3 ∼ 10 nm), uniform carbon layer (thickness of 3 ∼ 4 nm), high specific surface area (90.1 m 2 /g). As a result, the mesoporous LiMnPO 4 /C nanoparticles achieve excellent electrochemical performance as cathode materials for lithium ion batteries. It demonstrates a high discharge capacity of 167.7, 161.6, 156.4, 148.4 and 128.7 mAh/g at 0.1, 0.5, 1, 2 and 5C, and maintains a discharge capacity of 130.0 mAh/g after 100 cycles at 1C. The good electrochemical performance is attributed to its special interpenetrating mesoporous structure in LiMnPO 4 nanoparticles, which significantly enhances the ionic and electronic transport and additional capacitive behavior to compensate the sluggish kinetics.

  10. The micro and meso-porous materials. Characterization; Les materiaux micro et mesoporeux. Caracterisation

    Thibault-Starzyk, F.

    2004-10-01

    The micro and meso-porous materials, called zeolites, are very important in the modern chemical industry and in petrochemistry. This book deals in particular with the study and the characterization of zeolites. Its aim is to give to generalist chemists the tools for approaching experimentally these particular materials. The main methods of study and characterization are gathered in eight chapters, and the authors stress on the specificities due to the porous system: -structural analysis by the diffraction methods; -infrared spectroscopy; -NMR; -micro-calorimetry; -adsorption thermodynamics; -methods using the programed temperature; -modeling; -reactivity: kinetics and chemical engineering. This book appeals to students, engineers or searchers, without previous knowledge on these materials, but having a bachelor's degree or a master degree in general chemistry. (O.M.)

  11. Neodymium Recovery by Chitosan/Iron(III Hydroxide [ChiFer(III] Sorbent Material: Batch and Column Systems

    Hary Demey

    2018-02-01

    Full Text Available A low cost composite material was synthesized for neodymium recovery from dilute aqueous solutions. The in-situ production of the composite containing chitosan and iron(III hydroxide (ChiFer(III was improved and the results were compared with raw chitosan particles. The sorbent was characterized using Fourier transform infrared spectroscopy (FTIR and scanning electron microscopy-energy dispersive X-ray analyses (SEM-EDX. The equilibrium studies were performed using firstly a batch system, and secondly a continuous system. The sorption isotherms were fitted with the Langmuir, Freundlich, and Sips models; experimental data was better described with the Langmuir equation and the maximum sorption capacity was 13.8 mg g-1 at pH 4. The introduction of iron into the biopolymer matrix increases by four times the sorption uptake of the chitosan; the individual sorption capacity of iron (into the composite was calculated as 30.9 mg Nd/g Fe. The experimental results of the columns were fitted adequately using the Thomas model. As an approach to Nd-Fe-B permanent magnets effluents, a synthetic dilute effluent was simulated at pH 4, in order to evaluate the selectivity of the sorbent material; the overshooting of boron in the column system confirmed the higher selectivity toward neodymium ions. The elution step was carried out using MilliQ-water with the pH set to 3.5 (dilute HCl solution.

  12. Desorption Kinetics and Mechanisms of CO2 on Amine-Based Mesoporous Silica Materials

    Yang Teng

    2017-01-01

    Full Text Available Tetraethylenepentamine (TEPA-based mesoporous MCM-41 is used as the adsorbent to determine the CO2 desorption kinetics of amine-modified materials after adsorption. The experimental data of CO2 desorption as a function of time are derived by zero-length column at different temperatures (35, 50, and 70 °C and analyzed by Avrami’s fractional-order kinetic model. A new method is used to distinguish the physical desorption and chemical desorption performance of surface-modified mesoporous MCM-41. The activation energy Ea of CO2 physical desorption and chemical desorption calculated from Arrhenius equation are 15.86 kJ/mol and 57.15 kJ/mol, respectively. Furthermore, intraparticle diffusion and Boyd’s film models are selected to investigate the mechanism of CO2 desorption from MCM-41 and surface-modified MCM-41. For MCM-41, there are three rate-limiting steps during the desorption process. Film diffusion is more prominent for the CO2 desorption rates at low temperatures, and pore diffusion mainly governs the rate-limiting process under higher temperatures. Besides the surface reaction, the desorption process contains four rate-limiting steps on surface-modified MCM-41.

  13. Carboxylic acid-grafted mesoporous material and its high catalytic activity in one-pot three-component coupling reaction

    Ruth Gomes

    2014-11-01

    Full Text Available A new carboxylic acid functionalized mesoporous organic polymer has been synthesized via in situ radical polymerization of divinylbenzene and acrylic acid using a mesoporous silica as a seed during the polymerization process under solvothermal conditions. The mesoporous material MPDVAA-1 has been thoroughly characterized employing powder XRD, solid state 13C cross polarization magic angle spinning-nuclear magnetic resonance, FT-IR spectroscopy, N2 sorption, HR-TEM, and NH3 temperature programmed desorption-thermal conductivity detector (TPD-TCD analysis to understand its porosity, chemical environment, bonding, and surface properties. The mesoporous polymer was used as a catalyst for a three comp onent Biginelli condensation between various aldehydes, β-keto esters, and urea/thioureas to give 3,4-dihydropyrimidine-2(1H-ones. The reactions were carried out under conventional heating as well as solvent-free microwave irradiation of solid components, and in both the cases, the mesoporous polymer MPDVAA-1 proved to be a powerful, robust, and reusable catalyst with high catalytic efficiency.

  14. Cu(II) recognition materials: Fluorophores grafted on mesoporous silica supports

    Kledzik, Krzysztof; Orlowska, Maja; Patralska, Dorota; Gwiazda, Marcin; Jezierska, Julia; Pikus, Stanislaw; Ostaszewski, Ryszard; Klonkowski, Andrzej M.

    2007-01-01

    There were designed and synthesized naphthalene and pyrene derivatives consisting of fluorophore group and of receptor fragment with donor N and O atoms. These fluorosensors were covalently attached by grafting carboxyl group to surfaces of silica xerogel or mesoporous silicas (MCM-41 and MCM-48) functionalized either with 3-aminopropyl or 3-glycidoxypropyl groups. The pyrene derivatives 2 and 3 covalently grafted on MCM-48 silica functionalized with 3-aminopropyl groups are potential recognition elements of a fluorescence chemical sensor. Fluorescence emission of the prepared recognition materials is quenched specifically owing to photoinduced electron transfer (PET) effect after coordination reactions with Cu(II) ions. Moreover, both the materials exhibit selectivity for Cu(II) ions in aqueous solutions in presence of such metal ions as: alkali, alkaline earth and transition. During UV irradiation the studied recognition elements undergo slowly photochemical degradation

  15. Mesoporous nitrogen-rich carbon materials as cathode catalysts in microbial fuel cells

    Ahn, Yongtae

    2014-12-01

    The high cost of the catalyst material used for the oxygen reduction reaction in microbial fuel cell (MFC) cathodes is one of the factors limiting practical applications of this technology. Mesoporous nitrogen-rich carbon (MNC), prepared at different temperatures, was examined as an oxygen reduction catalyst, and compared in performance to Pt in MFCs and electrochemical cells. MNC calcined at 800 °C produced a maximum power density of 979 ± 131 mW m-2 in MFCs, which was 37% higher than that produced using MNC calined at 600 °C (715 ± 152 mW m-2), and only 14% lower than that obtained with Pt (1143 ± 54 mW m-2). The extent of COD removal and coulombic efficiencies were the same for all cathode materials. These results show that MNC could be used as an alternative to Pt in MFCs. © 2014 Elsevier B.V. All rights reserved.

  16. Modified mesoporous silica materials for on-line separation and preconcentration of hexavalent chromium using a microcolumn coupled with flame atomic absorption spectrometry

    Wang Zheng, E-mail: wangzheng@mail.sic.ac.cn [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Fang Dongmei; Li Qing [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); East China University of Science and Technology, Shanghai 200237 (China); Zhang Lingxia; Qian Rong; Zhu Yan; Qu Haiyun [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Du Yiping [East China University of Science and Technology, Shanghai 200237 (China)

    2012-05-06

    Highlights: Black-Right-Pointing-Pointer A modified SBA-15 mesoporous silica material (NH{sub 2}-SBA-15) was synthesized as sorbent. Black-Right-Pointing-Pointer The material was used for the first time in a flow injection on-line solid phase extraction (SPE) coupled with flame atomic absorption spectrometry (FAAS) to detect trace Cr (VI). Black-Right-Pointing-Pointer The NH{sub 2}-SBA-15 enables retain Cr (VI) with an enrichment factor of 44. Black-Right-Pointing-Pointer The micro-column of NH{sub 2}-SBA-15 underwent more than 100 adsorption/desorption cycles. - Abstract: A modified SBA-15 mesoporous silica material NH{sub 2}-SBA-15 was synthesized successfully by grafting {gamma}-aminopropyl-triethoxysilane. The material was characterized using transmission electron microscopy (TEM) and Fourier transform infrared/Raman (FT-IR/Raman) spectroscopy, and used for the first time in a flow injection on-line solid phase extraction (SPE) coupled with flame atomic absorption spectrometry (FAAS) to detect trace Cr (VI). Effective sorption of Cr (VI) was achieved at pH 2.0 with no interference from Cr (III) and other ions and 0.5 mol L{sup -1} NH{sub 3}{center_dot}H{sub 2}O solution was found optimal for the complete elution of Cr (VI). An enrichment factor of 44 and was achieved under optimized experimental conditions at a sample loading of 2.0 mL min{sup -1} sample loading (300 s) and an elution flow rate of 2.0 mL min{sup -1} (24 s). The precision of the 11 replicate Cr (VI) measurements was 2.1% at the 100 {mu}g L{sup -1} level with a detection limit of 0.2 {mu}g L{sup -1} (3 s, n = 10) using the FAAS. The developed method was successfully applied to trace chromium determination in waste water. The accuracy was validated using a certified reference material of riverine water (GBW08607).

  17. Mesoporous electrode material from alumina-stabilized anatase TiO.sub.2./sub. for lithium ion batteries

    Attia, Adel; Zukalová, Markéta; Rathouský, Jiří; Zukal, Arnošt; Kavan, Ladislav

    2005-01-01

    Roč. 9, č. 3 (2005), s. 134-145 ISSN 1432-8488 R&D Projects: GA ČR(CZ) GA203/03/0824 Institutional research plan: CEZ:AV0Z40400503 Keywords : titanium dioxide * alumina * lithium battery * mesoporous materials Subject RIV: CG - Electrochemistry Impact factor: 1.158, year: 2005

  18. Electrospun PVDF fibers and a novel PVDF/CoFe2O4 fibrous composite as nanostructured sorbent materials for oil spill cleanup

    Dorneanu, Petronela Pascariu; Cojocaru, Corneliu; Olaru, Niculae; Samoila, Petrisor; Airinei, Anton; Sacarescu, Liviu

    2017-12-01

    In this work, pure polyvinylidene fluoride (PVDF) and PVDF/cobalt ferrite (CoFe2O4) magnetic fibrous composite were successfully prepared by electrospinning method for oil spill sorption applications. The pure spinel phase of CoFe2O4 and PVDF/CoFe2O4 composites were confirmed by X-ray diffraction analysis (XRD). Electrospun sorbent materials were characterized by scanning and transmission electron microscopy (SEM and TEM) as well as by contact angle measurements. In addition, the composite sorbent (PVDF/CoFe2O4) was characterized by magnetic measurements. It revealed good magnetic properties that are of real interest to facilitate the separation of the oil-loaded sorbent under the external magnetic field. Finally, the produced electrospun sorbents were tested for sorption of oily liquids, such as: decane, dodecane and commercial motor oils. We obtained good oil sorption capacity (between 9.751-23.615 g/g of pure PVDF) and (8.133-18.074 g/g for the magnetic composite) depending on the nature of oil tested. The present electrospun magnetic PVDF/CoFe2O4 fibrous composite could be potentially useful for the efficient removal of oil in water and recovery of sorbent material.

  19. A mini review of designed mesoporous materials for energy-storage applications: from electric double-layer capacitors to hybrid supercapacitors

    Lim, Eunho; Jo, Changshin; Lee, Jinwoo

    2016-04-01

    In recent years, porous materials have attracted significant attention in various research fields because of their structural merits. In particular, well-designed mesoporous structures with two- or three-dimensionally interconnected pores have been recognized as electrode materials of particular interest for achieving high-performance electrochemical capacitors (ECs). In this mini review, recent progress in the design of mesoporous electrode materials for ECs, from electric double-layer capacitors (EDLCs) and pseudocapacitors (PCs) to hybrid supercapacitors (HSCs), and research challenges for the development of new mesoporous electrode materials has been discussed.

  20. Spectral studies on the interaction of acetylacetone with aluminum-containing MCM-41 mesoporous materials

    Zanjanchi, M.A.; Vaziri, M.

    2008-01-01

    Diffuse reflectance spectroscopy (DRS) was used to study the interaction of acetylacetone (acac) with the mesoporous aluminum-containing MCM-41 materials. A room temperature synthesis method was used for preparation of purely siliceous MCM-41 and for aluminum-containing MCM-41 materials. Samples with Si/Al ratios of 50, 20, 10 and 5 were synthesized. The synthesized mesoporous materials possess highly ordered structure and high surface area as evidenced from X-ray diffraction and nitrogen physisorption measurements, respectively. The treatment of the as-synthesized aluminum-containing MCM-41 samples with acac shows a distinct band at ∼290 nm. This band is assigned to six coordinated aluminum atoms in the structure which is produced by diffusion of acac molecules through surfactant micelles and their interaction with aluminum atoms. The 290-nm band disappears upon several successive washing of the sample with ethanol. The treatment of the calcined aluminum-containing MCM-41 sample with acac produces the same 290-nm band where its intensity increases with the aluminum content of the sample. The intensity of this band is reduced upon successive ethanol washing, but remains nearly constant after three times washing. This irremovable aluminum species can be assigned to framework aluminum. The measured acidity for our aluminum-containing MCM-41 samples correlates linearly with the intensity of 290-nm band for the ethanol treated samples. This supports the idea that the Bronsted acidity in aluminum-modified MCM-41 samples is a function of the amount of tetrahedral framework aluminum in the structure

  1. Natural material-decorated mesoporous silica nanoparticle container for multifunctional membrane-controlled targeted drug delivery

    Hu Y

    2017-11-01

    Full Text Available Yan Hu,1 Lei Ke,2 Hao Chen,1 Ma Zhuo,1 Xinzhou Yang,1 Dan Zhao,1 Suying Zeng,1 Xincai Xiao1 1Department of Pharmaceutics, School of Pharmaceutical Science, South-Central University for Nationalities, 2Department of Medicinal Chemistry, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People’s Republic of China Abstract: To avoid the side effects caused by nonspecific targeting, premature release, weak selectivity, and poor therapeutic efficacy of current nanoparticle-based systems used for drug delivery, we fabricated natural material-decorated nanoparticles as a multifunctional, membrane-controlled targeted drug delivery system. The nanocomposite material coated with a membrane was biocompatible and integrated both specific tumor targeting and responsiveness to stimulation, which improved transmission efficacy and controlled drug release. Mesoporous silica nanoparticles (MSNs, which are known for their biocompatibility and high drug-loading capacity, were selected as a model drug container and carrier. The membrane was established by the polyelectrolyte composite method from chitosan (CS which was sensitive to the acidic tumor microenvironment, folic acid-modified CS which recognizes the folate receptor expressed on the tumor cell surface, and a CD44 receptor-targeted polysaccharide hyaluronic acid. We characterized the structure of the nanocomposite as well as the drug release behavior under the control of the pH-sensitive membrane switch and evaluated the antitumor efficacy of the system in vitro. Our results provide a basis for the design and fabrication of novel membrane-controlled nanoparticles with improved tumor-targeting therapy. Keywords: multifunctional, membrane-controlled, natural materials, mesoporous silica nanoparticles, targeted drug delivery

  2. Polyaniline nanofiber/large mesoporous carbon composites as electrode materials for supercapacitors

    Liu, Huan; Xu, Bin; Jia, Mengqiu; Zhang, Mei; Cao, Bin; Zhao, Xiaonan; Wang, Yu

    2015-03-01

    A composite of polyaniline nanofiber/large mesoporous carbon (PANI-F/LMC) hybrid was prepared by an in situ chemical oxidative polymerization of aniline monomer with nano-CaCO3 templated LMC as host matrix for supercapacitors. The morphology, composition and electronic structure of the composites (PANI-F/LMC) together with pure PANI nanofibers and the LMC were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), FT-IR, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It is found that the PANI nanofibers were incorporated into the large mesochannels of LMC with interpenetrating framework formed. Such unique structure endows the PANI-F/LMC composite with a high capacitance of 473 F g-1 at a current load of 0.1 A g-1 with good rate performance and cycling stability, suggesting its potential application in the electrode material for supercapacitors.

  3. Performance of a Novel Hydrophobic Mesoporous Material for High Temperature Catalytic Oxidation of Naphthalene

    Guotao Zhao

    2014-01-01

    Full Text Available A high surface area, hydrophobic mesoporous material, MFS, has been successfully synthesized by a hydrothermal synthesis method using a perfluorinated surfactant, SURFLON S-386, as the single template. N2 adsorption and TEM were employed to characterize the pore structure and morphology of MFS. Static water adsorption test indicates that the hydrophobicity of MFS is significantly higher than that of MCM-41. XPS and Py-GC/MS analysis confirmed the existence of perfluoroalkyl groups in MFS which led to its high hydrophobicity. MFS was used as a support for CuO in experiments of catalytic combustion of naphthalene, where it showed a significant advantage over MCM-41 and ZSM-5. SEM was helpful in understanding why CuO-MFS performed so well in the catalytic combustion of naphthalene. Experimental results indicated that MFS was a suitable support for catalytic combustion of large molecular organic compounds, especially for some high temperature catalytic reactions when water vapor was present.

  4. Facile and tunable synthesis of hierarchical mesoporous silica materials ranging from flower structure with wrinkled edges to hollow structure with coarse surface

    Hao, Nanjing, E-mail: nanjing.hao@dartmouth.edu [Dartmouth College, Thayer School of Engineering (United States); Li, Laifeng; Tang, Fangqiong, E-mail: tangfq@mail.ipc.ac.cn [Chinese Academy of Sciences, Technical Institute of Physics and Chemistry (China)

    2016-11-15

    Mesoporous silica materials have attracted great attention in many fields. However, facile and tunable synthesis of hierarchical mesoporous silica structures is still a big challenge, and thus the development of them still lags behind. Herein, well-defined mesoporous silica flower structure with wrinkled edges and mesoporous silica hollow structure with coarse surface were synthesized simply by using poly(vinylpyrrolidone) and hexadecylamine as cotemplates in different water/ethanol solvent systems. The shape evolution from flower to hollow can be easily realized by tuning the volume ratio of water to ethanol, and the yields of both materials can reach gram scale. The formation mechanisms of mesoporous silica flower and hollow structures were also experimentally investigated and discussed. These novel hierarchical structures having unique physicochemical properties may bring many interesting insights into scientific research and technological application.

  5. Synthesis of acid-base bifunctional mesoporous materials by oxidation and thermolysis

    Yu, Xiaofang [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China); Zou, Yongcun [State Key Laboratory of Inoranic Synthesis and Preparative Chemistryg, College of Chemistry, Jilin University, Changchun 130012 (China); Wu, Shujie; Liu, Heng [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China); Guan, Jingqi, E-mail: guanjq@jlu.edu.cn [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China); Kan, Qiubin, E-mail: qkan@jlu.edu.cn [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China)

    2011-06-15

    Graphical abstract: A novel and efficient method has been developed for the synthesis of acid-base bifunctional catalyst. The obtained sample of SO{sub 3}H-MCM-41-NH{sub 2} containing amine and sulfonic acids exhibits excellent catalytic activity in aldol condensation reaction. Research highlights: {yields} Synthesize acid-base bifunctional mesoporous materials SO{sub 3}H-MCM-41-NH{sub 2}. {yields} Oxidation and then thermolysis to generate acidic site and basic site. {yields} Exhibit good catalytic performance in aldol condensation reaction between acetone and various aldehydes. -- Abstract: A novel and efficient method has been developed for the synthesis of acid-base bifunctional catalyst SO{sub 3}H-MCM-41-NH{sub 2}. This method was achieved by co-condensation of tetraethylorthosilicate (TEOS), 3-mercaptopropyltrimethoxysilane (MPTMS) and (3-triethoxysilylpropyl) carbamicacid-1-methylcyclohexylester (3TAME) in the presence of cetyltrimethylammonium bromide (CTAB), followed by oxidation and then thermolysis to generate acidic site and basic site. X-ray diffraction (XRD) and transmission electron micrographs (TEM) show that the resultant materials keep mesoporous structure. Thermogravimetric analysis (TGA), X-ray photoelectron spectra (XPS), back titration, solid-state {sup 13}C CP/MAS NMR and solid-state {sup 29}Si MAS NMR confirm that the organosiloxanes were condensed as a part of the silica framework. The bifunctional sample (SO{sub 3}H-MCM-41-NH{sub 2}) containing amine and sulfonic acids exhibits excellent acid-basic properties, which make it possess high activity in aldol condensation reaction between acetone and various aldehydes.

  6. The impact of framework organic functional groups on the hydrophobicity and overall stability of mesoporous silica materials

    Smeulders, Geert; Meynen, Vera; Silvestre-Albero, Ana; Houthoofd, Kristof; Mertens, Myrjam; Silvestre-Albero, Joaquin; Martens, Johan A.; Cool, Pegie

    2012-01-01

    Graphical abstract: The stability (hydrothermal, mechanical and chemical) of PMOs is studied in a systematic way and ranks them between classic and other hybrid mesoporous silica materials. Highlights: ► The stability (hydrothermal, mechanical and chemical) of PMOs is studied. ► Compared stability of PMOs with classic and other hybrid mesoporous silica materials. ► Immersion calorimetry to study the effect of hydrophobicity. ► PMOs show superior stability. - Abstract: The hydrothermal, mechanical and chemical stability of various mesoporous materials have been studied in detail, using X-ray diffraction and nitrogen sorption. Pure siliceous nanoporous powders (MCM-41 and SBA-15) are evaluated against their hybrid counterparts; namely 2 types of periodic mesoporous organosilicas (benzene and ethane bridged PMOs) and an organosilane grafted MCM-41 material. In primary tests, the stability of the hybrid materials is found to be superior compared to that of the pure siliceous ones. The stability of the materials was correlated to their hydrophobicity via immersion calorimetry, applied for the first time in this context. Based on these results, a clear correlation between the hydrophobicity of a material and its stability has been revealed. In addition, with 29 Si-MAS-NMR and vacuum experiments, the mechanism of the structural deterioration in the three different stability treatments could be unambiguously identified as the hydrolyzation of the siloxane bonds. The homogeneity of the hydrophobic groups throughout the entire network was found to be of great importance, irrespective of the hydrophobic nature at the surface as determined by calorimetric measurements. The results reveal that the most stable material can withstand (a) a pressure of 740 MPa during 5 min, (b) a 2 h stirring in a 2 M NaOH solution and (c) a 3 day steaming treatment at 393 K.

  7. The impact of framework organic functional groups on the hydrophobicity and overall stability of mesoporous silica materials

    Smeulders, Geert, E-mail: geert.smeulders@ua.ac.be [University of Antwerpen (Ukraine), Laboratory of Adsorption and Catalysis, Universiteitsplein 1, 2610 Wilrijk (Belgium); Meynen, Vera [University of Antwerpen (Ukraine), Laboratory of Adsorption and Catalysis, Universiteitsplein 1, 2610 Wilrijk (Belgium); Silvestre-Albero, Ana [Universidad de Alicante, Laboratorio de Materiales Avanzados, Apartado 99, 03080 Alicante (Spain); Houthoofd, Kristof [KULeuven, Centre for Surface Chemistry and Catalysis, Kasteelpark Arenberg 23, 3001 Heverlee (Belgium); Mertens, Myrjam [Flemish Institute for Technological Research (VITO N.V.), Boeretang 200, 2400 Mol (Belgium); Silvestre-Albero, Joaquin [Universidad de Alicante, Laboratorio de Materiales Avanzados, Apartado 99, 03080 Alicante (Spain); Martens, Johan A. [KULeuven, Centre for Surface Chemistry and Catalysis, Kasteelpark Arenberg 23, 3001 Heverlee (Belgium); Cool, Pegie [University of Antwerpen (Ukraine), Laboratory of Adsorption and Catalysis, Universiteitsplein 1, 2610 Wilrijk (Belgium)

    2012-02-15

    Graphical abstract: The stability (hydrothermal, mechanical and chemical) of PMOs is studied in a systematic way and ranks them between classic and other hybrid mesoporous silica materials. Highlights: Black-Right-Pointing-Pointer The stability (hydrothermal, mechanical and chemical) of PMOs is studied. Black-Right-Pointing-Pointer Compared stability of PMOs with classic and other hybrid mesoporous silica materials. Black-Right-Pointing-Pointer Immersion calorimetry to study the effect of hydrophobicity. Black-Right-Pointing-Pointer PMOs show superior stability. - Abstract: The hydrothermal, mechanical and chemical stability of various mesoporous materials have been studied in detail, using X-ray diffraction and nitrogen sorption. Pure siliceous nanoporous powders (MCM-41 and SBA-15) are evaluated against their hybrid counterparts; namely 2 types of periodic mesoporous organosilicas (benzene and ethane bridged PMOs) and an organosilane grafted MCM-41 material. In primary tests, the stability of the hybrid materials is found to be superior compared to that of the pure siliceous ones. The stability of the materials was correlated to their hydrophobicity via immersion calorimetry, applied for the first time in this context. Based on these results, a clear correlation between the hydrophobicity of a material and its stability has been revealed. In addition, with {sup 29}Si-MAS-NMR and vacuum experiments, the mechanism of the structural deterioration in the three different stability treatments could be unambiguously identified as the hydrolyzation of the siloxane bonds. The homogeneity of the hydrophobic groups throughout the entire network was found to be of great importance, irrespective of the hydrophobic nature at the surface as determined by calorimetric measurements. The results reveal that the most stable material can withstand (a) a pressure of 740 MPa during 5 min, (b) a 2 h stirring in a 2 M NaOH solution and (c) a 3 day steaming treatment at 393 K.

  8. Hierarchically ordered mesoporous carbon/graphene composites as supercapacitor electrode materials.

    Song, Yanjie; Li, Zhu; Guo, Kunkun; Shao, Ting

    2016-08-25

    Hierarchically ordered mesoporous carbon/graphene (OMC/G) composites have been fabricated by means of a solvent-evaporation-induced self-assembly (EISA) method. The structures of these composites are characterized by X-ray diffraction, transmission electron microscopy, Raman spectroscopy and nitrogen adsorption-desorption at 77 K. These results indicate that OMC/G composites possess the hierarchically ordered hexagonal p6mm mesostructure with the lattice unit parameter and pore diameter close to 10 nm and 3 nm, respectively. The specific surface area of OMC/G composites after KOH activation is high up to 2109.2 m(2) g(-1), which is significantly greater than OMC after activation (1474.6 m(2) g(-1)). Subsequently, the resulting OMC/G composites as supercapacitor electrode materials exhibit an outstanding capacitance as high as 329.5 F g(-1) in 6 M KOH electrolyte at a current density of 0.5 A g(-1), which is much higher than both OMC (234.2 F g(-1)) and a sample made by mechanical mixing of OMC with graphene (217.7 F g(-1)). In addition, the obtained OMC/G composites display good cyclic stability, and the final capacitance retention is approximately 96% after 5000 cycles. These ordered mesopores in the OMC/G composites are beneficial to the accessibility and rapid diffusion of the electrolyte, while graphene in OMC/G composites can also facilitate the transport of electrons during the processes of charging and discharging owing to its high conductivity, thereby leading to an excellent energy storage performance. The method demonstrated in this work would open up a new route to design and develop graphene-based architectures for supercapacitor applications.

  9. Mesoporous TiO2 : an alternative material for PEM fuel cells catalyst support

    Do, T.B. [Michigan Univ., Ann Arbor, MI (United States). Dept. of Materials Science; Ruthkosky, M.; Cai, M. [General Motors, Warren, MI (United States). Research and Development Center

    2008-07-01

    This paper discussed the feasibility of using an alternative catalyst support material to replace carbon in proton exchange membrane (PEM) fuel cells. The alternative catalyst support material requires a high surface area with a large porosity but must have comparable conductivity with carbon. A mesoporous titanium oxide (TiO2) material produced by coprecipitation was introduced. The conductivity of the material is about one order of that of carbon. The 8 mole per cent Nb-doped TiO2 was formed and deposited on the surface of a nano polystyrene (PS) template via the hydrolysis of a co-solution of Ti(OC4H9)4 and Nb(OC2H5)5. The removal of PS by heat treatment produced porous structure of TiO2 with the appearance of 3 different pore types, notably open pore, ink-pot pores and closed pores. TiO2 formed from the rutile phase, allowing a lower activation temperature at 850 degrees C in a hydrogen atmosphere. The pore structures were retained after this heat treatment. The BET surface area was 116 m{sup 2}/g, porosity was 22 per cent and the average pore size was 159 angstrom. The conductivity improved considerably from almost non-conductive to one order of that of carbon.

  10. Synthesis, Characterization and Application of the novel, regular mesoporous materials MCM-41 and MCM-48

    Schmidt, R

    1995-07-01

    In the application of zeolites to catalytic cracking of heavy oil fractions the need of regular solids with large pore sizes has become very obvious. The scope of this thesis was to synthesize and characterize the novel mesoporous materials MCM-41 and MCM-48 with the major emphasis laid on MCM-41. MCM-41 materials with bulk Si/Al ratios of 4, 9, 18 and {infinity} were synthesized and characterized by XRD and HREM. The catalytic cracking behaviour of Al-containing MCM-41 materials was investigated by pulse reactor studies using decalin as model feed and by Micro Activity Tests using atmospheric residue or n-hexadecane as feed. Aluminium containing MCM-41 was found to be active for the cracking of heavy oil fractions. Purely siliceous MCM-41 materials with pore sizes ranging from 18 Aa to 40 Aa were synthesized and their properties studied by means of NMR spectroscopy. The MCM-48, which is a cubic member of the M41S family with a three dimensional pore system, was studied by means of a combination of X-ray powder diffraction and HREM technique. 210 refs., 76 figs., 9 tabs.

  11. Ordered mesoporous carbide-derived carbon as new high performance electrode material in supercapacitors

    Korenblit, Yair; Yushin, Gleb [Georgia Inst. of Technology, Atlanta, GA (United States); Rose, Marcus; Kockrick, Emanuel; Borchardt, Lars; Kaskel, Stefan [Technische Univ. Dresden (Germany); Kvit, Alexander [Wisconsin Univ., Madison, WI (United States)

    2010-07-01

    The preparation and application of templated ordered mesoporous CDC overcome the present limitations of slow intraparticle ion transport and poor control over the biomodal pore size distribution in the carbons currently used, and shows a route for further performance enhancement. The ordered mesoporous channels in SiC CDC serve as ion-highways and allow for very fast ionic transport into the bulk of the CDC particles, thus leading to an excellent frequency response and outstanding capacitance retention at high current densities. The ordered mesopores in SiC allow for a greatly increased specific surface area and specific capacitance of SiC CDC, nearly doubling the previously reported values. The use of CDC produced from other carbides, including mesoporous TiC or VC is expected to further enhance the energy storage characteristics of EDLC electrodes, while optimization of the mesopore size is expected to enhance the power characteristics of EDLC. (orig.)

  12. Carbon nanocomposite sorbent and methods of using the same for separation of one or more materials from a gas stream

    Olson, Edwin S.; Pavlish, John Henry

    2017-05-30

    The present invention relates to carbon nanocomposite sorbents. The present invention provides carbon nanocomposite sorbents, methods for making the same, and methods for separation of a pollutant from a gas that includes that pollutant. Various embodiments provide a method for reducing the mercury content of a mercury-containing gas.

  13. Hierarchical micro- and mesoporous carbide-derived carbon as a high-performance electrode material in supercapacitors.

    Rose, Marcus; Korenblit, Yair; Kockrick, Emanuel; Borchardt, Lars; Oschatz, Martin; Kaskel, Stefan; Yushin, Gleb

    2011-04-18

    Ordered mesoporous carbide-derived carbon (OM-CDC) materials produced by nanocasting of ordered mesoporous silica templates are characterized by a bimodal pore size distribution with a high ratio of micropores. The micropores result in outstanding adsorption capacities and the well-defined mesopores facilitate enhanced kinetics in adsorption processes. Here, for the first time, a systematic study is presented, in which the effects of synthesis temperature on the electrochemical performance of these materials in supercapacitors based on a 1 M aqueous solution of sulfuric acid and 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid are reported. Cyclic voltammetry shows the specific capacitance of the OM-CDC materials exceeds 200 F g(-1) in the aqueous electrolyte and 185 F g(-1) in the ionic liquid, when measured in a symmetric configuration in voltage ranges of up to 0.6 and 2 V, respectively. The ordered mesoporous channels in the produced OM-CDC materials serve as ion-highways and allow for very fast ionic transport into the bulk of the OM-CDC particles. At room temperature the enhanced ion transport leads to 75% and 90% of the capacitance retention at current densities in excess of ∼10 A g(-1) in ionic liquid and aqueous electrolytes, respectively. The supercapacitors based on 250-300 μm OM-CDC electrodes demonstrate an operating frequency of up to 7 Hz in aqueous electrolyte. The combination of high specific capacitance and outstanding rate capabilities of the OM-CDC materials is unmatched by state-of-the art activated carbons and strictly microporous CDC materials. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Synthesis and electrochemical performance of mesoporous SiO{sub 2}–carbon nanofibers composite as anode materials for lithium secondary batteries

    Hyun, Yura; Choi, Jin-Yeong [Department of Chemistry, Keimyung University (Korea, Republic of); Park, Heai-Ku [Department of Chemical Engineering, Keimyung University (Korea, Republic of); Bae, Jae Young [Department of Chemistry, Keimyung University (Korea, Republic of); Lee, Chang-Seop, E-mail: surfkm@kmu.ac.kr [Department of Chemistry, Keimyung University (Korea, Republic of)

    2016-10-15

    Highlights: • Mesoporous SiO{sub 2}–carbon nanofibers composite synthesized on Ni foam without any binder. • This composite was directly applied as anode material of Li secondary batteries. • Showed the highest initial (2420 mAh/g) and discharging (2092 mAh/g) capacity. • This material achieved a retention rate of 86.4% after 30 cycles. - Abstract: In this study, carbon nanofibers (CNFs) and mesoporous SiO{sub 2}–carbon nanofibers composite were synthesized and applied as the anode materials in lithium secondary batteries. CNFs and mesoporous SiO{sub 2}–CNFs composite were grown via chemical vapor deposition method with iron-copper catalysts. Mesoporous SiO{sub 2} materials were prepared by sol–gel method using tetraethylorthosilicate as the silica source and cetyltrimethylammoniumchloride as the template. Ethylene was used as the carbon source and passes into a quartz reactor of a tube furnace heated to 600 °C, and the temperature was maintained at 600 °C for 10 min to synthesize CNFs and mesoporous SiO{sub 2}–CNFs composite. The electrochemical characteristics of the as-prepared CNFs and mesoporous SiO{sub 2}–CNFs composite as the anode of lithium secondary batteries were investigated using a three-electrode cell. In particular, the mesoporous SiO{sub 2}–CNFs composites synthesized without binder after depositing mesoporous SiO{sub 2} on Ni foam showed the highest charging and discharging capacity and retention rate. The initial capacity (2420 mAh/g) of mesoporous SiO{sub 2}–CNFs composites decreased to 2092 mAh/g after 30 cycles at a retention rate of 86.4%.

  15. Synthesis and characterization of mesoporous materials for CO_2 capture: influence of nickel oxide

    Nascimento, Alexsandra Rodrigues do

    2014-01-01

    Several materials are currently under study for the CO_2 capture process, like the metal oxides and mixed metal oxides, zeolites, carbonaceous materials, metal-organic frameworks (MOF's) organosilica and modified silica surfaces. In this work, evaluated the adsorption capacity of CO_2 in mesoporous materials of different structures, such as MCM-48 and SBA-15 without impregnating and impregnated with nickel in the proportions 5 %, 10 % and 20 % (m/m), known as 5Ni-MCM-48, 10Ni-MCM-48, 20Ni-MCM-48 and 5Ni-SBA-15, 10Ni-SBA-15, 20Ni-SBA-15. The materials were characterized by means of X-ray diffraction (XRD), thermal analysis (TG and DTG), Fourier transform infrared spectroscopy (FT-IR), N_2 adsorption and desorption (BET) and scanning electron microscopy (SEM) with EDS. The adsorption process was performed varying the pressure of 100 - 4000 kPa and keeping the temperature constant and equal to 298 K. At a pressure of 100 kPa, higher concentrations of adsorption occurred for the materials 5Ni-MCM-48 (0.795 mmol g"-"1) and SBA-15 (0.914 mmol g"-"1) is not impregnated, and at a pressure of 4000 kPa for MCM-48 materials (14.89 mmol g"-"1) and SBA-15 (9.97 mmol g"-"1) not impregnated. The results showed that the adsorption capacity varies positively with the specific area, however, has a direct dependency on the type and geometry of the porous structure of channels. The data were fitted using the Langmuir and Freundlich models and were evaluated thermodynamic parameters Gibbs free energy and entropy of the adsorption system. (author)

  16. Mesoporous ethanesilica materials with bimodal and trimodal pore-size distributions synthesised in the presence of cobalt ions

    Alufelwi M. Tshavhungwe

    2010-07-01

    Full Text Available Mesoporous organosilica materials containing ethane groups in their framework were formed with two and three pore sizes (i.e. bimodal and trimodal pores when synthesised by the sol-gel method in the presence of cobalt ions. The compounds 1,2-bistrimethoxysilylethane and tetraethylorthosilicate were used as silicon sources and the reactions were done in the presence of a surfactant, which served as a template. Diffuse reflectance infrared Fourier transform spectroscopy revealed that organic functional groups were incorporated into the ethanesilica. Powder X-ray diffraction and nitrogen adsorption data indicated that the mesophase and textural properties (surface area, pore volume, pore diameter of the materials were dependent on the ageing temperature, the amount/ratio of silica precursors and cobalt ion incorporation. Secondary mesopores were drastically reduced by changing the ratio of silicon precursors.

  17. A new certified reference material for benzene measurement in air on a sorbent tube: development and proficiency testing

    Caurant, A. [Laboratoire National de Metrologie et d' Essais, Paris (France); Universite Paris 12 et CNRS (UMR 7583), Faculte des Sciences et Technologie, Laboratoire Inter-universitaire des Systemes Atmospheriques, Unite Mixte de Recherche Universite Paris 7 (France); Lalere, B.; Schbath, M.C.; Stumpf, C.; Sutour, C.; Mace, T.; Vaslin-Reimann, S. [Laboratoire National de Metrologie et d' Essais, Paris (France); Quisefit, J.P.; Doussin, J.F. [Universite Paris 12 et CNRS (UMR 7583), Faculte des Sciences et Technologie, Laboratoire Inter-universitaire des Systemes Atmospheriques, Unite Mixte de Recherche Universite Paris 7 (France)

    2010-11-15

    A certified matrix reference material (CRM) for the measurement of benzene in ambient air has been developed at Laboratoire National de Metrologie et d'Essais. The production of these CRMs was conducted using a gravimetric method fully traceable to the International System of Units. The CRMs were prepared by sampling an accurate mass of a gaseous primary reference material of benzene, using a high-precision laminar flowmeter and a mass flow controller, with a PerkinElmer sampler filled with Carbopack trademark X sorbent. The relative standard deviations obtained for the preparation of a batch of 20 tubes loaded with 500 ng of benzene were below 0.2%. Each CRM is considered independent from the others and with its own certified value and an expanded uncertainty estimated to be within 0.5%, lower than the uncertainties of benzene CRMs already available worldwide. The stability of these materials was also established up to 12 months. These CRMs were implemented during proficiency testing, to evaluate the analytical performances of seven French laboratories involved in benzene air monitoring. (orig.)

  18. Ordered molecular arrays as templates: A new approach to synthesis of mesoporous materials

    Behrens, P.; Stucky, G.

    There has been a growing interest in the extension of the microporous molecular sieve synthesis and applications to mesoscopic dimensions. Typical areas for the application of mesoscopic zeolite-type structures are in separation (e.g., protein separation and selective adsorption of large organic molecules from waste waters) and catalysis (e.g., processing of tar sand and of the high distillates of crude oils to valuable low-boiling products). Another is in the supramolecular assembly of molecular array and polymers for electronic and optical applications. In a new concept in the synthesis of porous material the templating agent is no longer a single, solvated, organic molecule or metal ion, but rather a self-assembled molecular array. This template leads to mesoporous materials with adjustable pore sizes between 16 and greater than 100 Angstrom, covering well the mesophorous range of greatest interest. The periodic arrangement of pores is very regular, and the pore size distribution measured by absorption is nearly as sharp as that of conventional zeolites.

  19. Outstanding low temperature HC-SCR of NOx over platinum-group catalysts supported on mesoporous materials expecting diesel-auto emission regulation

    Komatsu, Tamikuni; Tomokuni, Keizou; Yamada, Issaku

    2006-01-01

    Outstanding low temperature HC-SCR of NOx over platinum-group catalysts supported on mesoporous materials, which does not rely on the conventional NOx-absorption-reduction-catalysts, is presented for the purpose of de-NOx of diesel-auto emissions. The established catalysts basically consist of mesoporous silica or metal-substituted mesoporous silicates for supports and platinum for active species, which is operated under lean- and rich-conditions. The new catalysts are very active at 150-200 o C and free from difficult problems of SOx-deactivation and hydrothermal ageing of the NOx-absorption-reduction catalyst. (author)

  20. Magnetic solid-phase extraction based on mesoporous silica-coated magnetic nanoparticles for analysis of oral antidiabetic drugs in human plasma

    Souza, Karynne Cristina de; Andrade, Gracielle Ferreira [Centro de Desenvolvimento da Tecnologia Nuclear, CDTN/CNEN, Rua Professor Mário Werneck, s/n. Campus Universitário, Belo Horizonte, MG CEP 30.123-970 (Brazil); Vasconcelos, Ingrid; Oliveira Viana, Iara Maíra de; Fernandes, Christian [Departamento de Produtos Farmacêuticos, Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil); Martins Barros de Sousa, Edésia, E-mail: sousaem@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear, CDTN/CNEN, Rua Professor Mário Werneck, s/n. Campus Universitário, Belo Horizonte, MG CEP 30.123-970 (Brazil)

    2014-07-01

    In the present work, magnetic nanoparticles embedded into mesoporous silica were prepared in two steps: first, magnetite was synthesized by oxidation–precipitation method, and next, the magnetic nanoparticles were coated with mesoporous silica by using nonionic block copolymer surfactants as structure-directing agents. The mesoporous SiO{sub 2}-coated Fe{sub 3}O{sub 4} samples were functionalized using octadecyltrimethoxysilane as silanizing agent. The pure and functionalized silica nanoparticles were physicochemically and morphologically characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N{sub 2} adsorption, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The resultant magnetic silica nanoparticles were applied as sorbents for magnetic solid-phase extraction (MSPE) of oral antidiabetic drugs in human plasma. Our results revealed that the magnetite nanoparticles were completely coated by well-ordered mesoporous silica with free pores and stable pore walls, and that the structural and magnetic properties of the Fe{sub 3}O{sub 4} nanoparticles were preserved in the applied synthesis route. Indeed, the sorbent material was capable of extracting the antidiabetic drugs from human plasma, being useful for the sample preparation in biological matrices. - Highlights: • SBA-15/Fe{sub 3}O{sub 4} was synthesized and functionalized with octadecyltrimethoxysilane. • Magnetite nanoparticles were completely coated by well-ordered mesoporous silica. • The samples were used as sorbent for magnetic solid-phase extraction (MSPE). • The sorbent material was capable of extracting drugs from human plasma. • The extraction ability makes the material a candidate to be employed as MSPE.

  1. Synthesis of Hydrophobic Mesoporous Material MFS and Its Adsorption Properties of Water Vapor

    Guotao Zhao

    2014-01-01

    Full Text Available Fluorine-containing hydrophobic mesoporous material (MFS with high surface area is successfully synthesized with hydrothermal synthesis method by using a perfluorinated surfactant SURFLON S-386 template. The adsorption properties of water vapor on the synthesized MFS are also investigated by using gravimetric method. Results show that SEM image of the MFS depicted roundish morphology with the average crystal size of 1-2 μm. The BET surface area and total pore volume of the MFS are 865.4 m2 g−1 and 0.74 cm3 g−1 with a narrow pore size distribution at 4.9 nm. The amount of water vapor on the MFS is about 0.41 mmol g−1 at 303 K, which is only 52.6% and 55.4% of MCM-41 and SBA-15 under the similar conditions, separately. The isosteric adsorption heat of water on the MFS is gradually about 27.0–19.8 kJ mol−1, which decreases as the absorbed water vapor amount increases. The value is much smaller than that on MCM-41 and SBA-15. Therefore, the MFS shows more hydrophobic surface properties than the MCM-41 and SBA-15. It may be a kind of good candidate for adsorption of large molecule and catalyst carrier with high moisture resistance.

  2. Heat storage properties of organic phase-change materials confined in the nanospace of mesoporous SBA-15 and CMK-3.

    Kadoono, Tomosuke; Ogura, Masaru

    2014-03-28

    A novel type of material encapsulating phase-change materials (PCMs) is reported concerning their implication for use as thermal energy storage devices. The composites of siliceous SBA-15 or carbonaceous CMK-3 mesoporous assemblies and organic PCMs could be used to make leak-free devices that retain their capabilities over many thermal cycles for heat storage/release. A confinement effect was observed that alters the thermal properties of the encapsulated PCM, especially in CMK-3 without any similar effects in other carbon materials.

  3. Mesoporous amine-bridged polysilsesquioxane for CO2 capture

    Qi, Genggeng; Fu, Liling; Duan, Xiaonan; Choi, Brian Hyun; Abraham, Michael; Giannelis, Emmanuel P.

    2011-01-01

    A novel class of amine-supported sorbents based on amine-bridged mesoporous polysilsesquioxane was developed via a simple one-pot sol-gel process. The new sorbent allows the incorporation of a large amount of active groups without sacrificing

  4. Synthesis and characterization of silica mesoporous material produced by hydrothermal continues pH adjusting path way

    A. Salemi Golezani

    2016-08-01

    Full Text Available Mesoporous silica molecular sieves MCM-41 were synthesized under hydrothermal conditions. For this purpose, a solution with a molar coefficient of water, cetyltri-methyl ammonium bromide surfactants as template and sodium silicate as the source of SiO2 are used. Phase formation, morphology and gas absorption properties were investigated by XRD and BET analysis, respectively. The results showed that silica mesoporous material has been successfully synthesized. A favorable special surface and porosity volume together with regular arrangement of nano metric-hexagonal porosities were obtained from this synthesis. Thickness of the wall and average diameter of the pores are 0.8 nm and 4 nm, respectively.

  5. Mesoporous MnO2/carbon aerogel composites as promising electrode materials for high-performance supercapacitors.

    Li, Gao-Ren; Feng, Zhan-Ping; Ou, Yan-Nan; Wu, Dingcai; Fu, Ruowen; Tong, Ye-Xiang

    2010-02-16

    MnO(2) as one of the most promising candidates for electrochemical supercapacitors has attracted much attention because of its superior electrochemical performance, low cost, and environmentally benign nature. In this Letter, we explored a novel route to prepare mesoporous MnO(2)/carbon aerogel composites by electrochemical deposition assisted by gas bubbles. The products were characterized by energy-dispersive spectrometry (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The MnO(2) deposits are found to have high purity and have a mesoporous structure that will optimize the electronic and ionic conductivity to minimize the total resistance of the system and thereby maximize the performance characteristics of this material for use in supercapacitor electrodes. The results of nitrogen adsorption-desorption experiments and electrochemical measurements showed that these obtained mesoporous MnO(2)/carbon aerogel composites had a large specific surface area (120 m(2)/g), uniform pore-size distribution (around 5 nm), high specific capacitance (515.5 F/g), and good stability over 1000 cycles, which give these composites potential application as high-performance supercapacitor electrode materials.

  6. Sorbent Film-Coated Passive Samplers for Explosives Vapour Detection Part A: Materials Optimisation and Integration with Analytical Technologies.

    McEneff, Gillian L; Murphy, Bronagh; Webb, Tony; Wood, Dan; Irlam, Rachel; Mills, Jim; Green, David; Barron, Leon P

    2018-04-11

    A new thin-film passive sampler is presented as a low resource dependent and discrete continuous monitoring solution for explosives-related vapours. Using 15 mid-high vapour pressure explosives-related compounds as probes, combinations of four thermally stable substrates and six film-based sorbents were evaluated. Meta-aramid and phenylene oxide-based materials showed the best recoveries from small voids (~70%). Analysis was performed using liquid chromatography-high resolution accurate mass spectrometry which also enabled tentative identification of new targets from the acquired data. Preliminary uptake kinetics experiments revealed plateau concentrations on the device were reached between 3-5 days. Compounds used in improvised explosive devices, such as triacetone triperoxide, were detected within 1 hour and were stably retained by the sampler for up to 7 days. Sampler performance was consistent for 22 months after manufacture. Lastly, its direct integration with currently in-service explosives screening equipment including ion mobility spectrometry and thermal desorption mass spectrometry is presented. Following exposure to several open environments and targeted interferences, sampler performance was subsequently assessed and potential interferences identified. High-security building and area monitoring for concealed explosives using such cost-effective and discrete passive samplers can add extra assurance to search routines while minimising any additional burden on personnel or everyday site operation.

  7. Quasi 2D Mesoporous Carbon Microbelts Derived from Fullerene Crystals as an Electrode Material for Electrochemical Supercapacitors.

    Tang, Qin; Bairi, Partha; Shrestha, Rekha Goswami; Hill, Jonathan P; Ariga, Katsuhiko; Zeng, Haibo; Ji, Qingmin; Shrestha, Lok Kumar

    2017-12-27

    Fullerene C 60 microbelts were fabricated using the liquid-liquid interfacial precipitation method and converted into quasi 2D mesoporous carbon microbelts by heat treatment at elevated temperatures of 900 and 2000 °C. The carbon microbelts obtained by heat treatment of fullerene C 60 microbelts at 900 °C showed excellent electrochemical supercapacitive performance, exhibiting high specific capacitances ca. 360 F g -1 (at 5 mV s -1 ) and 290 F g -1 (at 1 A g -1 ) because of the enhanced surface area and the robust mesoporous framework structure. Additionally, the heat-treated carbon microbelt showed good rate performance, retaining 49% of capacitance at a high scan rate of 10 A g -1 . The carbon belts exhibit super cyclic stability. Capacity loss was not observed even after 10 000 charge/discharge cycles. These results demonstrate that the quasi 2D mesoporous carbon microbelts derived from a π-electron-rich carbon source, fullerene C 60 crystals, could be used as a new candidate material for electrochemical supercapacitor applications.

  8. Mesoporous Zn2SnO4 as effective electron transport materials for high-performance perovskite solar cells

    Bao, Sha; Wu, Jihuai; He, Xin; Tu, Yongguang; Wang, Shibo; Huang, Miaoliang; Lan, Zhang

    2017-01-01

    Highlights: •Large grain and mesoporous Zn 2 SnO 4 are synthesized by a facile hydrothermal method. •Perovskite device with Zn 2 SnO 4 electron transport layer get efficiency of 17.21%. •While the device with TiO 2 electron transport layer obtain an efficiency of 14.83%. •Superior photovoltaic performance stems from the intrinsic characteristics of Zn 2 SnO 4 . -- Abstract: Electron transport layer with higher carrier mobility and suitable band gap structure plays a significant role in determining the photovoltaic performance of perovskite solar cells (PSCs). Here, we report a synthesis of high crystalline zinc stannate (Zn 2 SnO 4 ) by a facile hydrothermal method. The as-synthesized Zn 2 SnO 4 possesses particle size of 20 nm, large surface area, mesoporous hierarchical structure, and can be used as a promising electron-transport materials to replace the conventional mesoporous TiO 2 material. A perovskite solar cell with structure of FTO/blocking layer/Zn 2 SnO 4 /CH 3 NH 3 PbI 3 /Spiro-OMeOTAD/Au is fabricated, and the preparation condition is optimized. The champion device based on Zn 2 SnO 4 electron transport material achieves a power conversion efficiency of 17.21%, while the device based on TiO 2 electron transport material gets an efficiency of 14.83% under the same experimental conditions. The results render Zn 2 SnO 4 an effective candidate as electron transport material for high performance perovskite solar cells and other devices.

  9. Probing properties, stability, and performances of hierarchical meso-porous materials with nano-scale interfaces

    Baldinozzi, Gianguido; Gosset, Dominique; Simeone, David; Muller, Guillaume; Laberty-Robert, Christel; Sanchez, Clement

    2012-01-01

    Nano-crystals growth mechanism embedded into meso-porous thin films has been determined directly from grazing incidence X-ray diffraction data. We have shown, for the first time, that surface capillary forces control the growth mechanism of nano-crystals into these nano-architectures. Moreover, these data allow an estimation of the surface tension of the nano-crystals organized into a 3-D nano-architecture. The analysis of the variations in the strain field of these nano-crystals gives information on the evolution of the microstructure of these meso-porous films, that is, the contacts among nano-crystals. This work represents the first application of grazing incidence X-ray for understanding stability and performances of meso-porous thin films. This approach can be used to understand the structural stability of these nano-architectures at high temperature. (authors)

  10. Use of natural clays as sorbent materials for rare earth ions: Materials characterization and set up of the operative parameters.

    Iannicelli-Zubiani, Elena Maria; Cristiani, Cinzia; Dotelli, Giovanni; Gallo Stampino, Paola; Pelosato, Renato; Mesto, Ernesto; Schingaro, Emanuela; Lacalamita, Maria

    2015-12-01

    Two mineral clays of the montmorillonite group were tested as sorbents for the removal of Rare Earths (REs) from liquid solutions. Lanthanum and neodymium model solutions were used to perform uptake tests in order to: (a) verify the clays sorption capability, (b) investigate the sorption mechanisms and (c) optimize the experimental parameters, such as contact time and pH. The desorption was also studied, in order to evaluate the feasibility of REs recovery from waters. The adsorption-desorption procedure with the optimized parameters was also tested on a leaching solution obtained by dissolution of a dismantled NdFeB magnet of a hard-disk. The clays were fully characterized after REs adsorption and desorption by means of X-ray powder diffraction (XRPD) and X-ray photoelectron spectroscopy (XPS); the liquid phase was characterized via Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) analyses. The experimental results show that both clays are able to capture and release La and Nd ions, with an ion exchange mechanism. The best total efficiency (capture ≈ 50%, release ≈ 70%) is obtained when the uptake and release processes are performed at pH=5 and pH=1 respectively; in real leached scrap solutions, the uptake is around 40% but release efficiency is strongly decreased passing from a mono-ion system to a real system (from 80% to 5%). Furthermore, a strong matrix effect is found, with the matrix largely affecting both the uptake and the release of neodymium. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. First-Principles Integrated Adsorption Modeling for Selective Capture of Uranium from Seawater by Polyamidoxime Sorbent Materials.

    Ladshaw, Austin P; Ivanov, Alexander S; Das, Sadananda; Bryantsev, Vyacheslav S; Tsouris, Costas; Yiacoumi, Sotira

    2018-04-18

    Nuclear power is a relatively carbon-free energy source that has the capacity to be utilized today in an effort to stem the tides of global warming. The growing demand for nuclear energy, however, could put significant strain on our uranium ore resources, and the mining activities utilized to extract that ore can leave behind long-term environmental damage. A potential solution to enhance the supply of uranium fuel is to recover uranium from seawater using amidoximated adsorbent fibers. This technology has been studied for decades but is currently plagued by the material's relatively poor selectivity of uranium over its main competitor vanadium. In this work, we investigate the binding schemes between uranium, vanadium, and the amidoxime functional groups on the adsorbent surface. Using quantum chemical methods, binding strengths are approximated for a set of complexation reactions between uranium and vanadium with amidoxime functionalities. Those approximations are then coupled with a comprehensive aqueous adsorption model developed in this work to simulate the adsorption of uranium and vanadium under laboratory conditions. Experimental adsorption studies with uranium and vanadium over a wide pH range are performed, and the data collected are compared against simulation results to validate the model. It was found that coupling ab initio calculations with process level adsorption modeling provides accurate predictions of the adsorption capacity and selectivity of the sorbent materials. Furthermore, this work demonstrates that this multiscale modeling paradigm could be utilized to aid in the selection of superior ligands or ligand compositions for the selective capture of metal ions. Therefore, this first-principles integrated modeling approach opens the door to the in silico design of next-generation adsorbents with potentially superior efficiency and selectivity for uranium over vanadium in seawater.

  12. Ibuprofen in mesopores of Mobil Crystalline Material 41 (MCM-41): a deeper understanding.

    Skorupska, Ewa; Jeziorna, Agata; Paluch, Piotr; Potrzebowski, Marek J

    2014-05-05

    In this work, we compared two methods (incipient wetness and melting) for the encapsulation of ibuprofen in the pores of Mobil Crystalline Material 41 (MCM-41) through NMR (nuclear magnetic resonance) spectroscopy. (1)H NMR spectra were recorded under very fast MAS (sample spinning 60 kHz) conditions in both 1D and 2D mode (NOESY sequence). We also performed (13)C cross-polarization magic angle spinning (CP/MAS) experiments, (13)C single pulse experiments (SPE), and (1)H-(13)C HSQC HR/MAS (heteronuclear single quantum coherence high resolution) HR/MAS correlations. Evaluation of the encapsulation methods included an analysis of the filling factor of the drug into the pores. The stability of Ibu/MCM in an environment of ethanol or water vapor was tested. Our study showed that melting a mixture of Ibu and MCM is a much more efficient method of confining the drug in the pores compared to incipient wetness. The optimal experiments for the former method achieved a filling factor of approximately 60%. We concluded that the major limitation to the applicability of the incipient wetness method (filling factor ca. 20%) is the high affinity of solvent (typically ethanol) for MCM-41. We found that even ethanol vapor can remove Ibu from the pores. When a sample of Ibu/MCM was stored for a few hours in a closed vessel with ethanol vapor, Ibu was transported from the pores to the outer walls of MCM. We observed a similar phenomenon with water vapor, although this process is slower compared to the analogous procedure using ethanol. Our study clearly demonstrates that existing methods used to encapsulate drugs in mesoporous silica nanoparticles (MSNs) require reevaluation.

  13. A novel molybdenum disulfide nanosheet self-assembled flower-like monolithic sorbent for solid-phase extraction with high efficiency and long service life.

    Ran, Fanpeng; Liu, Hongmei; Wang, Xiaoqi; Guo, Yong

    2017-07-21

    A novel material consisting of molybdenum disulfide (MoS 2 ) nanosheet that self-assemble into flower-like microspheres which aggregate to form a monolithic matrix with a micro or nano-scaled mesopore structure was successfully synthesized and used as an efficient sorbent for solid-phase extraction (SPE) due to its large specific adsorption area and good stability. The extraction properties of the as-prepared sorbent were evaluated by high-performance liquid chromatography with variable wavelength detection (HPLC-VWD) by analyzing four flavonoids (apigenin, quercetin, luteolin, and kaempferol). Under optimal conditions, the LODs and LOQs were found to be in the ranges of 0.1-0.25 and 0.4-0.5μgL -1 , respectively, and wide linear ranges were obtained with correlation coefficients (R) ranging from 0.9991 to 0.9996. Compared with commercial C18 and Alumina-N sorbents, the as-prepared sorbent showed high extraction efficiency at different concentrations of flavonoids. After 100 uses, the extraction ability of the self-assembled MoS 2 nanosheet monolithic sorbent had no evident decline, denoting a long service life. Finally, the SPE-HPLC-VWD method using the as-prepared sorbent was applied to flavonoid analysis in beverage samples with satisfactory results. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Fabrication of mesoporous metal oxide coated-nanocarbon hybrid materials via a polyol-mediated self-assembly process

    Feng, Bingmei; Wang, Huixin; Wang, Dongniu; Yu, Huilong; Chu, Yi; Fang, Hai-Tao

    2014-11-01

    After clarifying the formation mechanism of a typical metal glycolate precipitate, Ti glycolate, in a polyol-mediated synthesis using acetone as a precipitation medium, we describe a simple template-free approach based on an ethylene glycol-mediated synthesis to fabricate mesoporous metal oxide coated-nanocarbon hybrid materials including TiO2 coated-carbon nanotube (CNT), SnO2 coated-CNT, Cu2O/CuO coated-CNT and TiO2 coated-graphene sheet (GS). In the approach, metal oxide precursors, metal glycolates, were first deposited on CNTs or GSs, and subsequently transformed to the metal oxide coatings by pyrolysis or hydrolysis. By a comparison between the characterization of two TiO2-CNT hybrid materials using carboxylated CNTs and pristine CNTs without carboxyl groups, the driving force for initiating the deposition of metal glycolates on the carboxylated CNTs is confirmed to be the hydrogen bonding between the carboxyl groups and the polymer chains in metal glycolate sols. The electrochemical performances of the mesoporous TiO2 coated-carboxylated CNTs and TiO2-pristine CNT hybrid materials were investigated. The results show that the mesoporous TiO2 coated-carboxylated CNT with a uniform core-shell nanostructure exhibits substantial improvement in the rate performance in comparison with its counterpart from 0.5 C to 100 C because of its higher electronic conductivity and shorter diffusion path for the lithium ion. At the extremely high rate of 100 C, the specific capacity of TiO2 of the former reaches 85 mA h g-1, twice as high as that of the latter.After clarifying the formation mechanism of a typical metal glycolate precipitate, Ti glycolate, in a polyol-mediated synthesis using acetone as a precipitation medium, we describe a simple template-free approach based on an ethylene glycol-mediated synthesis to fabricate mesoporous metal oxide coated-nanocarbon hybrid materials including TiO2 coated-carbon nanotube (CNT), SnO2 coated-CNT, Cu2O/CuO coated-CNT and TiO2

  15. Mesoporous Co3O4 nanosheets-3D graphene networks hybrid materials for high-performance lithium ion batteries

    Sun, Hongyu; Liu, Yanguo; Yu, Yanlong; Ahmad, Mashkoor; Nan, Ding; Zhu, Jing

    2014-01-01

    Graphical abstract: - Highlights: • The mesoporous Co 3 O 4 nanosheets-3D graphene networks have been found to display better LIB performance as compare with Co 3 O 4 /CNT and Co 3 O 4 structures. • Electrochemical impedance spectroscopy shows that the addition of 3DGN largely enhanced the electrochemical activity of Co 3 O 4 during the cycling processes. • The large specific surface area and porous nature of the Co 3 O 4 nanosheets are very convenient and accessible for electrolyte diffusion and intercalation of Li + ions into the active phases. - Abstract: Mesoporous Co 3 O 4 nanosheets-3D graphene networks (3DGN) hybrid materials have been synthesized by combining chemical vapor deposition (CVD) and hydrothermal method and investigated as anode materials for Li-ion batteries (LIBs). Microscopic characterizations have been performed to confirm the 3DGN and mesoporous Co 3 O 4 nanostructures. The specific surface area and pore size of the hybrid structures have been found ∼ 34.5 m 2 g −1 and ∼ 3.8 nm respectively. It has been found that the Co 3 O 4 /3DGNs composite displays better LIB performance with enhanced reversible capacity, good cyclic performance and rate capability as compare with Co 3 O 4 /CNT and Co 3 O 4 structures. Electrochemical impedance spectroscopy (EIS) results show that the addition of 3DGN not only preserves high conductivity of the composite electrode, but also largely enhanced the electrochemical activity of Co 3 O 4 during the cycling processes. The improved electrochemical performance is considered due to the addition of 3DGNs which prevent the cracking of electrode. In addition, the large specific surface area and porous nature of the Co 3 O 4 nanosheets are also very convenient and accessible for electrolyte diffusion and intercalation of Li + ions into the active phases. Therefore, this combination can be considered to be an attractive candidate as an anode material for LIBs

  16. Templating mesoporous zeolites

    Egeblad, Kresten; Christensen, Christina Hviid; Kustova, Marina

    2008-01-01

    The application of templating methods to produce zeolite materials with hierarchical bi- or trimodal pore size distributions is reviewed with emphasis on mesoporous materials. Hierarchical zeolite materials are categorized into three distinctly different types of materials: hierarchical zeolite...... crystals, nanosized zeolite crystals, and supported zeolite crystals. For the pure zeolite materials in the first two categories, the additional meso- or macroporosity can be classified as being either intracrystalline or intercrystalline, whereas for supported zeolite materials, the additional porosity...... originates almost exclusively from the support material. The methods for introducing mesopores into zeolite materials are discussed and categorized. In general, mesopores can be templated in zeolite materials by use of solid templating, supramolecular templating, or indirect templating...

  17. Low-cost route for synthesis of mesoporous silica materials with high silanol groups and their application for Cu(II) removal

    Wang Yangang; Huang Sujun; Kang Shifei; Zhang Chengli; Li Xi

    2012-01-01

    Graphical abstract: A simple and low-cost route to synthesize mesoporous silica materials with high silanol groups has been demonstrated by means of a sol–gel process using citric acid as the template and acid catalyst, further studies on the adsorption of Cu(II) onto the representative amine-functionalized mesoporous silica showed that it had a high Cu(II) removal efficiency. Highlights: ► A low-cost route to synthesize mesoporous silica with high silanol groups was demonstrated. ► Citric acid as the template and acid catalyst for the reaction of tetraethylorthosilicate. ► Water extraction method was an effective technique to remove template which can be recycled. ► The mesoporous silica with high silanol groups was easily modified by functional groups. ► A high Cu(II) removal efficiency on the amine-functionalized mesoporous silica. - Abstract: We report a simple and low-cost route for the synthesis of mesoporous silica materials with high silanol groups by means of a sol–gel process using citric acid as the template, tetraethylorthosilicate (TEOS) as the silica source under aqueous solution system. The citric acid can directly work as an acid catalyst for the hydrolysis of TEOS besides the function as a pore-forming agent in the synthesis. It was found that by using a water extraction method the citric acid template in as-prepared mesoporous silica composite can be easily removed and a high degree of silanol groups were retained in the mesopores, moreover, the citric acid template in the filtrate can be recycled after being dried. The structural properties of the obtained mesoporous silica materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and nitrogen adsorption–desorption analysis. Furthermore, an adsorption of Cu(II) from aqueous solution on the representative amine-functionalized mesoporous silica was investigated

  18. The Effect of Mesoporous Carbon Nitride Modification by Titanium Oxide Nanoparticles on Photocatalytic Degradation of 1,3-Dinitrobenzene

    Seyyed Ershad Moradi

    2015-11-01

    Full Text Available In the present work, well ordered, mesoporous carbon nitride (MCN sorbent with uniform mesoporous wall, high surface area and pore volume has been fabricated using the simple polymerization reaction between ethylene diamine and carbon tetrachloride in mesoporous silica media, and then modified by TiO2 nanoparticles (Ti-MCN. The structural order and textural properties of the nanoporous materials were studied by XRD, elemental analysis, and nitrogen adsorption–desorption experiments. Photodegradation experiments for 1,3-dinitrobenzene were conducted in batch mode, the Ti-MCN catalysts were found to be more active compared to the free TiO2 nanoparticles for 1,3-dinitrobenzene degradation.

  19. Post-combustion carbon capture - solid sorbents and membranes

    Davidson, R.M.

    2009-01-15

    This report follows on from that on solvent scrubbing for post-combustion carbon capture from coal-fired power plants by considering the use of solid sorbents and membranes instead of solvents. First, mesoporous and microporous adsorbents are discussed: carbon-based adsorbents, zeolites, hydrotalcites and porous crystals. Attempts have been made to improve the performance of the porous adsorbent by functionalising them with nitrogen groups and specifically, amine groups to react with CO{sub 2} and thus enhance the physical adsorption properties. Dry, regenerable solid sorbents have attracted a good deal of research. Most of the work has been on the carbonation/calcination cycle of natural limestone but there have also been studies of other calcium-based sorbents and alkali metal-based sorbents. Membranes have also been studied as potential post-combustion capture devices. Finally, techno-economic studies predicting the economic performance of solid sorbents and membranes are discussed. 340 refs., 21 figs., 8 tabs.

  20. Novel sorbents for environmental remediation

    Manariotis, Ioannis D.; Karapanagioti, Hrissi K.; Werner, David

    2014-05-01

    Nowadays, one of the major environmental problems is the pollution of aquatic systems and soil by persistent pollutants. Persistent pollutants have been found widespread in sediments, surface waters, and drinking water supplies. The removal of pollutants can be accomplished prior to their discharge to receiving bodies or by immobilizing them onto soil. Sorption is the most commonly applied process, and activated carbons have been widely used. Rapid progress in nanotechnology and a new focus on biomass-based instead of non-renewable starting materials have produced a wide range of novel engineered sorbents including biosorbents, biochars, carbon-based nanoparticles, bio-nano hybrid materials, and iron-impregnated activated carbons. Sorbent materials have been used in environmental remediation processes and especially in agricultural soil, sediments and contaminated soil, water treatment, and industrial wastewater treatment. Furthermore, sorbents may enhance the synergistic action of other processes, such as volatilization and biodegradation. Novel sorbents have been employed for the removal or immobilization of persistent pollutants such as and include heavy metals (As, Cr, Cu, Pb, Cd, and Hg), halogenated organic compounds, endocrine disrupting chemicals, metalloids and non-metallic elements, and other organic pollutants. The development and evaluation of novel sorbents requires a multidisciplinary approach encompassing environmental, nanotechnology, physical, analytical, and surface chemistry. The necessary evaluations encompass not only the efficiency of these materials to remove pollutants from surface waters and groundwater, industrial wastewater, polluted soils and sediments, etc., but also the potential side-effects of their environmental applications. The aim of this work is to present the results of the use of biochar and impregnated carbon sorbents for the removal of organic pollutants and metals. Furthermore, the new findings from the forthcoming session

  1. Facile synthesis of mesoporous NiFe2O4/CNTs nanocomposite cathode material for high performance asymmetric pseudocapacitors

    Kumar, Nagesh; Kumar, Amit; Huang, Guan-Min; Wu, Wen-Wei; Tseng, Tseung Yuen

    2018-03-01

    Morphology and synergistic effect of constituents are the two very important factors that greatly influence the physical, chemical and electrochemical properties of a composite material. In the present work, we report the enhanced electrochemical performance of mesoporous NiFe2O4 and multiwall carbon nanotubes (MWCNTs) nanocomposites synthesized via hexamethylene tetramine (HMT) assisted one-pot hydrothermal approach. The synthesized cubic phase spinel NiFe2O4 nanomaterial possesses high specific surface area (148 m2g-1) with narrow mesopore size distribution. The effect of MWCNTs addition on the electrochemical performance of nanocomposite has been probed thoroughly in a normal three electrode configuration using 2 M KOH electrolyte at room temperature. Experimental results show that the addition of mere 5 mg MWCNTs into fixed NiFe2O4 precursors amount enhances the specific capacitance up to 1291 F g-1 at 1 A g-1, which is the highest reported value for NiFe2O4 nanocomposites so far. NiFe2O4/CNT nanocomposite exhibits small relaxation time constant (1.5 ms), good rate capability and capacitance retention of 81% over 500 charge-discharge cycles. This excellent performance can be assigned to high surface area, mesoporous structure of NiFe2O4 and conducting network formed by MWCNTs in the composite. Further, to evaluate the device performance of the composite, an asymmetric pseudocapacitor has been designed using NiFe2O4/CNT nanocomposite as a positive and N-doped graphene as a negative electrode material, respectively. Our designed asymmetric pseudocapacitor gives maximum energy density of 23 W h kg-1 at power density of 872 W kg-1. These promising results assert the potential of synthesized nanocomposite in the development of efficient practical high-capacitive energy storage devices.

  2. Aminopropyl-modified mesoporous molecular sieves as efficient adsorbents for removal of auxins

    Moritz, Michał; Geszke-Moritz, Małgorzata

    2015-01-01

    Graphical abstract: Adsorption of indole-3-acetic acid (IAA) on aminopropyl-modified mesoporous sieves. - Highlights: • Four types of mesoporous molecular sieves were used as sorbents for removal of auxins. • SBA-15, MCF, PHTS and SBA-16 were grafted with (3-aminopropyl)triethoxysilane. • The adsorption capacity of modified materials was higher as compared to pure silicas. • Surface modification and pore volume play important role in adsorption process. - Abstract: In the present study, mesoporous siliceous materials grafted with 3-aminopropyltriethoxysilane (APTES) were examined as sorbents for removal of chosen plant growth factors (auxins) such as 1-naphthaleneacetic acid (NAA), indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA). Four different types of mesoporous molecular sieves including SBA-15, PHTS, SBA-16 and MCF have been prepared via non-ionic surfactant-assisted soft templating method. Silica molecular sieves were thoroughly characterized by nitrogen adsorption–desorption analysis, powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FT-IR). The maximum adsorption capacity (Q max ) for NAA, IAA and IBA was in the range from 51.0 to 140.8 mg/g and from 4.3 to 7.3 mg/g for aminopropyl-modified adsorbents and pure silicas, respectively. The best adsorption performance was observed for IAA entrapment using both APTES-functionalized SBA-15 and MCF matrices (Q max of 140.8 and 137.0 mg/g, respectively) which can be ascribed to their larger pore volumes and pore diameters. Moreover, these silicas were characterized by the highest adsorption efficiency exceeding 90% at low pollutant concentration. The experimental points for adsorption of plant growth factors onto aminopropyl-modified mesoporous molecular sieves fitted well to the Langmuir equation

  3. Aminopropyl-modified mesoporous molecular sieves as efficient adsorbents for removal of auxins

    Moritz, Michał, E-mail: michal.moritz@put.poznan.pl [Poznan University of Technology, Faculty of Chemical Technology, Institute of Chemistry and Technical Electrochemistry, Berdychowo 4, 60-965 Poznań (Poland); Geszke-Moritz, Małgorzata, E-mail: Malgorzata.Geszke-Moritz@amu.edu.pl [NanoBioMedical Centre, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland)

    2015-03-15

    Graphical abstract: Adsorption of indole-3-acetic acid (IAA) on aminopropyl-modified mesoporous sieves. - Highlights: • Four types of mesoporous molecular sieves were used as sorbents for removal of auxins. • SBA-15, MCF, PHTS and SBA-16 were grafted with (3-aminopropyl)triethoxysilane. • The adsorption capacity of modified materials was higher as compared to pure silicas. • Surface modification and pore volume play important role in adsorption process. - Abstract: In the present study, mesoporous siliceous materials grafted with 3-aminopropyltriethoxysilane (APTES) were examined as sorbents for removal of chosen plant growth factors (auxins) such as 1-naphthaleneacetic acid (NAA), indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA). Four different types of mesoporous molecular sieves including SBA-15, PHTS, SBA-16 and MCF have been prepared via non-ionic surfactant-assisted soft templating method. Silica molecular sieves were thoroughly characterized by nitrogen adsorption–desorption analysis, powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FT-IR). The maximum adsorption capacity (Q{sub max}) for NAA, IAA and IBA was in the range from 51.0 to 140.8 mg/g and from 4.3 to 7.3 mg/g for aminopropyl-modified adsorbents and pure silicas, respectively. The best adsorption performance was observed for IAA entrapment using both APTES-functionalized SBA-15 and MCF matrices (Q{sub max} of 140.8 and 137.0 mg/g, respectively) which can be ascribed to their larger pore volumes and pore diameters. Moreover, these silicas were characterized by the highest adsorption efficiency exceeding 90% at low pollutant concentration. The experimental points for adsorption of plant growth factors onto aminopropyl-modified mesoporous molecular sieves fitted well to the Langmuir equation.

  4. Collection and identification of human remains volatiles by non-contact, dynamic airflow sampling and SPME-GC/MS using various sorbent materials.

    DeGreeff, Lauryn E; Furton, Kenneth G

    2011-09-01

    Human remains detection canines are used in locating deceased humans in diverse scenarios and environments based on odor produced during the decay process of the human body. It has been established that human remains detection canines are capable of locating human remains specifically, as opposed to living humans or animal remains, thus suggesting a difference in odor between the different sources. This work explores the collection and determination of such odors using a dynamic headspace concentration device. The airflow rate and three sorbent materials-Dukal cotton gauze, Johnson & Johnson cotton-blend gauze, and polyester material-used for odor collection were evaluated using standard compounds. It was determined that higher airflow rates and openly woven material, e.g., Dukal cotton gauze, yielded significantly less total volatile compounds due to compound breakthrough through the sorbent material. Collection from polymer- and cellulose-based materials demonstrated that the molecular backbone of the material is a factor in compound collection as well. Volatiles, including cyclic and straight-chain hydrocarbons, organic acids, sulfides, aldehydes, ketones, and alcohols, were collected from a population of 27 deceased bodies from two collection locations. The common compounds between the subjects were compared and the odor profiles were determined. These odor profiles were compared with those of animal remains and living human subjects collected in the same manner. Principal component analysis showed that the odor profiles of the three sample types were distinct.

  5. Micro-mesoporous carbon spheres derived from carrageenan as electrode material for supercapacitors

    Fan, Yang; Yang, Xin; Zhu, Bing; Liu, Pei-Fang; Lu, Hai-Ting

    2014-12-01

    The polysaccharide carrageenan is used as a natural precursor to prepare micro-mesoporous carbon spheres. The carbon spheres were synthesized by hydrothermal carbonization of carrageenan, and subsequent chemical activation by KOH at different temperatures. The obtained micro-mesoporous carbon spheres have high surface area (up to 2502 m2 g-1) and large pore volume (up to 1.43 cm3 g-1). Moreover, the micro- and mesoporosity can be finely tuned be modifying the activation temperatures in the range of 700-900 °C. The carbon spheres activated at 900 °C present high specific capacitance of 230 F g-1 at a current density of 1 A g-1 and good ion transport kinetics. The good capacitive performance can be ascribed to the high specific surface area, well-controlled micro- and mesoporosity and narrow pore size distribution.

  6. Mesoporous silica materials modified with alumina polycations as catalysts for the synthesis of dimethyl ether from methanol

    Macina, Daniel; Piwowarska, Zofia; Tarach, Karolina; Góra-Marek, Kinga [Jagiellonian University, Faculty of Chemistry, Ingardena 3, 30-060 Kraków (Poland); Ryczkowski, Janusz [Maria Curie Skłodowska University, Faculty of Chemistry, Maria Curie-Skłodowska 2, 20-031 Lublin (Poland); Chmielarz, Lucjan, E-mail: chmielar@chemia.uj.edu.pl [Jagiellonian University, Faculty of Chemistry, Ingardena 3, 30-060 Kraków (Poland)

    2016-02-15

    Highlights: • Deposition of alumina ologoctaions on mesoporous silicas modified with surface −SO{sub 3}H groups. • Alumina aggregates generated acid properties in the silica supports. • Alumina modified SBA-15 and MCF were active and selective catalysts in DME synthesis. - Abstract: Mesoporous silica materials (SBA-15 and MCF) were used as catalytic supports for the deposition of aggregated alumina species using the method consisting of the following steps: (i) anchoring 3-(mercaptopropyl)trimethoxysilane (MPTMS) on the silica surface followed by (ii) oxidation of −SH to−SO{sub 3}H groups and then (iii) deposition of aluminum Keggin oligocations by ion-exchange method and (iv) calcination. The obtained samples were tested as catalysts for synthesis of dimethyl ether from methanol. The modified silicas were characterized with respect to the ordering of their porous structure (XRD), textural properties (BET), chemical composition (EDS, CHNS), structure ({sup 27}Al NMR, FTIR) and location of alumina species (EDX-TEM), surface acidity (NH{sub 3}-TPD, Py-FTIR) and thermal stability (TGA). The obtained materials were found to be active and selective catalysts for methanol dehydration to dimethyl ether (DME) in the MTD process (methanol-to-dimethyl ether).

  7. Facile synthesis of single-crystal mesoporous CoNiO2 nanosheets assembled flowers as anode materials for lithium-ion batteries

    Liu, Yanguo; Zhao, Yanyan; Yu, Yanlong; Ahmad, Mashkoor; Sun, Hongyu

    2014-01-01

    Highlights: • Mesoporous CoNiO 2 microflowers have been synthesized. • Li-ion batteries performance of CoNiO 2 has been investigated. • CoNiO 2 structure delivers high capacity, good cycling stability and high rate capability. • The electrochemical performance is attributed to the mesoporous nature and the 3D structure. • CoNiO 2 can be considered to be an attractive candidate as an electrode material for LIBs. - Abstract: Mesoporous CoNiO 2 microflowers assembled with single-crystal nanosheets were successfully synthesized by a hydrothermal method and subsequent annealing process and their lithium storage capacity were investigated. The structural and compositional analysis of the mesoporous CoNiO 2 microflowers has been studied by X-ray diffraction, field emission scanning electron microscopy and high-resolution transmission electron microscopy. The Bruauer–Emmett–Teller specific surface area of CoNiO 2 microflowers has been calculated by the nitrogen isotherm curve and pore size distribution has been determined by the Barret–Joyner–Halenda method. It has been found that the as-prepared CoNiO 2 electrodes delivered satisfied capacity, good cycling stability and rate capability. The improved electrochemical performance is attributed to the mesoporous nature and the 3D assembled structure. Therefore, such a structure can be considered to be an attractive candidate as an electrode material for lithium-ion batteries

  8. Synthesis and characterization of V, Mo and Nb incorporated micro-mesoporous MCM-41 materials

    Solmaz, Arzu, E-mail: arzu.solmaz@rshm.gov.tr [Gazi University, Faculty of Engineering, Chemical Engineering Department, 06570 Ankara (Turkey); Balci, Suna, E-mail: sunabalci@gazi.edu.tr [Gazi University, Faculty of Engineering, Chemical Engineering Department, 06570 Ankara (Turkey); Dogu, Timur, E-mail: tdogu@metu.edu.tr [Middle East Technical University, Faculty of Engineering, Chemical Engineering Department, 06531 Ankara (Turkey)

    2011-01-01

    Highly microporous metal-MCM-41 ordered mesoporous structure catalysts having different metal/Si (V, Mo, Nb) atomic ratios and combinations of metal sources were hydrothermally synthesized. The structural properties estimated using different techniques were found to be in agreement with each other. Metals were successfully incorporated into MCM-41 without deteriorating the ordered hexagonal structure. The metal ions in the synthesis solutions probably settled on the hydrophilic end of the template hence the metal incorporation resulted improvements in the micropore structure. Low loading of metals caused an increase in the surface area and pore volume values of the catalysts. The highest total (1310 m{sup 2} g{sup -1}) and micropore surface area values (1083 m{sup 2} g{sup -1}) were obtained by Nb incorporation. The micro- and mesopore dimensions of MCM-41 increased from 0.5 to 1.1 nm and from 2.5 to 2.8 nm, respectively, with metal incorporation. Low V/Si ratios and presence of Nb in the starting solution enhanced narrow mesopore size distribution. The pore dimension and wall thickness values estimated from nitrogen adsorption and X-ray diffraction methods were consistent with the corresponding values obtained using transmission electron microscopy.

  9. CaO-based CO2 sorbents: from fundamentals to the development of new, highly effective materials.

    Kierzkowska, Agnieszka M; Pacciani, Roberta; Müller, Christoph R

    2013-07-01

    The enormous anthropogenic emission of the greenhouse gas CO2 is most likely the main reason for climate change. Considering the continuing and indeed growing utilisation of fossil fuels for electricity generation and transportation purposes, development and implementation of processes that avoid the associated emissions of CO2 are urgently needed. CO2 capture and storage, commonly termed CCS, would be a possible mid-term solution to reduce the emissions of CO2 into the atmosphere. However, the costs associated with the currently available CO2 capture technology, that is, amine scrubbing, are prohibitively high, thus making the development of new CO2 sorbents a highly important research challenge. Indeed, CaO, readily obtained through the calcination of naturally occurring limestone, has been proposed as an alternative CO2 sorbent that could substantially reduce the costs of CO2 capture. However, one of the major drawbacks of using CaO derived from natural sources is its rapidly decreasing CO2 uptake capacity with repeated carbonation-calcination reactions. Here, we review the current understanding of fundamental aspects of the cyclic carbonation-calcination reactions of CaO such as its reversibility and kinetics. Subsequently, recent attempts to develop synthetic, CaO-based sorbents that possess high and cyclically stable CO2 uptakes are presented. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Electrochemical behavior of two and one electron redox systems adsorbed on to micro- and mesoporous silicate materials: Influence of the channels and the cationic environment of the host materials

    Senthil Kumar, K.; Natarajan, P.

    2009-01-01

    Electrochemical behavior of two electron redox system, phenosafranine (PS + ) adsorbed on to micro- and mesoporous materials is investigated by cyclic voltammetry and differential pulse voltammetry using modified micro- and mesoporous host electrodes. Two redox peaks were observed when phenosafranine is adsorbed on the surface of microporous materials zeolite-Y and ZSM-5. However, only a single redox peak was observed in the modified electrode with phenosafranine encapsulated into the mesoporous material MCM-41 and when adsorbed on the external surface of silica. The observed redox peaks for the modified electrodes with zeolite-Y and ZSM-5 host are suggested to be primarily due to consecutive two electron processes. The peak separation ΔE and peak potential of phenosafranine adsorbed on zeolite-Y and ZSM-5 were found to be influenced by the pH of the electrolyte solution. The variation of the peak current in the cyclic voltammogram and differential pulse voltammetry with scan rate shows that electrodic processes are controlled by the nature of the surface of the host material. The heterogeneous electron transfer rate constants for phenosafranine adsorbed on to micro- and mesoporous materials were calculated using the Laviron model. Higher rate constant observed for the dye encapsulated into the MCM-41 indicates that the one-dimensional channel of the mesoporous material provides a more facile micro-environment for phenosafranine for the electron transfer reaction as compared to the microporous silicate materials. The stability of the modified electrode surface was investigated by multisweep cyclic voltammetry.

  11. MoO2-ordered mesoporous carbon nanocomposite as an anode material for lithium-ion batteries.

    Zeng, Lingxing; Zheng, Cheng; Deng, Cuilin; Ding, Xiaokun; Wei, Mingdeng

    2013-03-01

    In the present work, the nanocomposite of MoO2-ordered mesoporous carbon (MoO2-OMC) was synthesized for the first time using a carbon thermal reduction route and the mesoporous carbon as the nanoreactor. The synthesized nanocomposite was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), N2 adsorption-desorption, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) measurements. Furthermore, this nanocomposite was used as an anode material for Li-ion intercalation and exhibited large reversible capacity, high rate performance, and good cycling stability. For instance, a high reversible capacity of 689 mAh g(-1) can remain after 50 cycles at a current density of 50 mA g(-1). It is worth mentioning that the MoO2-OMC nanocomposite electrode can attain a high reversible capacity of 401 mAh g(-1) at a current density as high as 2 A g(-1). These results might be due to the intrinsic characteristics of nanocomposite, which offered a better accommodation of the strain and volume changes and a shorter path for Li-ion and electron transport, leading to the improved capacity and enhanced rate capability.

  12. Mesoporous MFe{sub 2}O{sub 4} (M = Mn, Co, and Ni) for anode materials of lithium-ion batteries: Synthesis and electrochemical properties

    Duan, Lianfeng, E-mail: duanlf@mail.ccut.edu.cn [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Key Laboratory of Advanced Structural Materials, Ministry of Education, and Department of Materials Science and Engineering, Changchun University of Technology, Changchun 130012 (China); Wang, Yuanxin; Wang, Linan [Key Laboratory of Advanced Structural Materials, Ministry of Education, and Department of Materials Science and Engineering, Changchun University of Technology, Changchun 130012 (China); Zhang, Feifei [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, Limin [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2015-01-15

    Highlights: • MFe{sub 2}O{sub 4} (M = Mn, Co, and Ni) are synthesized by a template-free hydrothermal method. • The mesoporous morphology is formed by self-assembly of crystal nucleus. • The mesporous MnFe{sub 2}O{sub 4} have the active phase and the synergy for Li-ion storage. - Abstract: The MFe{sub 2}O{sub 4} (M = Mn, Co, and Ni) mesoporous spheres with an average diameter of 250 nm were synthesized through a template-free hydrothermal method. The mesoporous MnFe{sub 2}O{sub 4} with a large surface area of 87.5 m{sup 2}/g and an average pore size of 27.52 nm were obtained. As the anode materials for Li-ion batteries, the mesoporous MnFe{sub 2}O{sub 4} exhibits excellent initial charge and discharge capacities of 1010 and 642.5 mA h/g. After 50 cycles, the discharge capacity could still remain at 379 mA h/g. The results showed that the active phase and the synergy between different metal oxides greatly improved the electrochemical performance, and the mesoporous composite could stabilize the structure of the electrodes.

  13. Introduction to the first International Workshop on the Application of Microporous and Mesoporous Materials as Catalytic Hosts for Fe, Cu an Co

    Donk, van S.; Weckhuysen, B.M.; Kapteijn, F.; Kooyman, P.J.; Hensen, E.J.M.

    2005-01-01

    This Special Issue of Catalysis Today includes a selection of research presented at the first International Workshop on the ‘Application of Microporous and Mesoporous Materials as Catalytic Hosts for Fe, Cu and Co’, held in Scheveningen, The Netherlands, 1–4 March 2005. This 3-day event welcomed

  14. Synthesis of an Ionic Liquid and Its Application as Template for the Preparation of Mesoporous Material MCM-41: A Comprehensive Experiment for Undergraduate Students

    Hu, Jun; Yin, Jinxiang; Lin, Tianshu; Li, Guangtao

    2012-01-01

    A new solvent-free microwave experiment to synthesize the ionic liquid 1-hexadecyl-3-methylimidazolium bromide (HDMIm-Br) in high yield is presented. The structure is confirmed by IR and [superscript 1]H NMR spectra. HDMIm-Br is then used to prepare an organic-inorganic mesoporous material MCM-41. The microscopic arrangements of mesoporous…

  15. NMR studies of organic liquids confined in mesoporous materials: (1) Pore size distribution and (2) Phase behaviour and dynamic studies in restricted geometry

    Foerland, Kjersti

    2005-01-01

    In the thesis NMR spectroscopy is used for studying liquids confined in various porous materials. In the first part, pore size distributions of mesoporous silicas and controlled pore glasses were determined by measuring the 1H NMR signal from the non-frozen fraction of the confined liquid as a function of temperature, using benzene, acetonitrile and HMDS as probe molecules. In the second part, the molecular dynamics of acetonitrile, hexamethyldisilane, cyclohexane and cyclopentane confined in mesoporous materials were studied as a function of temperature. 6 papers are included with titles: 1) Pore-size determination of mesoporous materials by 1H NMR spectroscopy. 2) Pore-size distribution in mesoporous materials as studied by 1H NMR. 3) Dynamic 1H and 2H NMR investigations of acetonitrile confined in porous silica. 4) NMR investigations of hexamethyldisilane confined in controlled pore glasses: Pore size distribution and molecular dynamics studies. 5) 1H and 2H NMR studies of cyclohexane nano crystals in controlled pore glasses. 6) 1H NMR relaxation and diffusion studies of cyclohexane and cyclopentane confined in MCM-41

  16. NMR studies of organic liquids confined in mesoporous materials: (1) Pore size distribution and (2) Phase behaviour and dynamic studies in restricted geometry

    Foerland, Kjersti

    2005-07-01

    In the thesis NMR spectroscopy is used for studying liquids confined in various porous materials. In the first part, pore size distributions of mesoporous silicas and controlled pore glasses were determined by measuring the 1H NMR signal from the non-frozen fraction of the confined liquid as a function of temperature, using benzene, acetonitrile and HMDS as probe molecules. In the second part, the molecular dynamics of acetonitrile, hexamethyldisilane, cyclohexane and cyclopentane confined in mesoporous materials were studied as a function of temperature. 6 papers are included with titles: 1) Pore-size determination of mesoporous materials by 1H NMR spectroscopy. 2) Pore-size distribution in mesoporous materials as studied by 1H NMR. 3) Dynamic 1H and 2H NMR investigations of acetonitrile confined in porous silica. 4) NMR investigations of hexamethyldisilane confined in controlled pore glasses: Pore size distribution and molecular dynamics studies. 5) 1H and 2H NMR studies of cyclohexane nano crystals in controlled pore glasses. 6) 1H NMR relaxation and diffusion studies of cyclohexane and cyclopentane confined in MCM-41.

  17. Mesoporous aluminum phosphite

    El Haskouri, Jamal; Perez-Cabero, Monica; Guillem, Carmen; Latorre, Julio; Beltran, Aurelio; Beltran, Daniel; Amoros, Pedro

    2009-01-01

    High surface area pure mesoporous aluminum-phosphorus oxide-based derivatives have been synthesized through an S + I - surfactant-assisted cooperative mechanism by means of a one-pot preparative procedure from aqueous solution and starting from aluminum atrane complexes and phosphoric and/or phosphorous acids. A soft chemical extraction procedure allows opening the pore system of the parent as-prepared materials by exchanging the surfactant without mesostructure collapse. The nature of the pore wall can be modulated from mesoporous aluminum phosphate (ALPO) up to total incorporation of phosphite entities (mesoporous aluminum phosphite), which results in a gradual evolution of the acidic properties of the final materials. While phosphate groups in ALPO act as network building blocks (bridging Al atoms), the phosphite entities become basically attached to the pore surface, what gives practically empty channels. The mesoporous nature of the final materials is confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and N 2 adsorption-desorption isotherms. The materials present regular unimodal pore systems whose order decreases as the phosphite content increases. NMR spectroscopic results confirm the incorporation of oxo-phosphorus entities to the framework of these materials and also provide us useful information concerning the mechanism through which they are formed. - Abstract: TEM image of the mesoporous aluminum phosphite showing the hexagonal disordered pore array that is generated by using surfactant micelles as template. Also a scheme emphasizing the presence of an alumina-rich core and an ALPO-like pore surface is presented.

  18. Development of Novel Sorbents for Uranium Extraction from Seawater

    Lin, Wenbin [Univ. of Chicago, IL (United States); Taylor-Pashow, Kathryn [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2014-01-08

    As the uranium resource in terrestrial ores is limited, it is difficult to ensure a long-term sustainable nuclear energy technology. The oceans contain approximately 4.5 billion tons of uranium, which is one thousand times the amount of uranium in terrestrial ores. Development of technologies to recover the uranium from seawater would greatly improve the uranium resource availability, sustaining the fuel supply for nuclear energy. Several methods have been previously evaluated including solvent extraction, ion exchange, flotation, biomass collection, and adsorption; however, none have been found to be suitable for reasons such as cost effectiveness, long term stability, and selectivity. Recent research has focused on the amidoxime functional group as a promising candidate for uranium sorption. Polymer beads and fibers have been functionalized with amidoxime functional groups, and uranium adsorption capacities as high as 1.5 g U/kg adsorbent have recently been reported with these types of materials. As uranium concentration in seawater is only ~3 ppb, great improvements to uranium collection systems must be made in order to make uranium extraction from seawater economically feasible. This proposed research intends to develop transformative technologies for economic uranium extraction from seawater. The Lin group will design advanced porous supports by taking advantage of recent breakthroughs in nanoscience and nanotechnology and incorporate high densities of well-designed chelators into such nanoporous supports to allow selective and efficient binding of uranyl ions from seawater. Several classes of nanoporous materials, including mesoporous silica nanoparticles (MSNs), mesoporous carbon nanoparticles (MCNs), meta-organic frameworks (MOFs), and covalent-organic frameworks (COFs), will be synthesized. Selective uranium-binding liagnds such as amidoxime will be incorporated into the nanoporous materials to afford a new generation of sorbent materials that will be

  19. Development of Novel Sorbents for Uranium Extraction from Seawater

    Lin, Wenbin; Taylor-Pashow, Kathryn

    2014-01-01

    As the uranium resource in terrestrial ores is limited, it is difficult to ensure a long-term sustainable nuclear energy technology. The oceans contain approximately 4.5 billion tons of uranium, which is one thousand times the amount of uranium in terrestrial ores. Development of technologies to recover the uranium from seawater would greatly improve the uranium resource availability, sustaining the fuel supply for nuclear energy. Several methods have been previously evaluated including solvent extraction, ion exchange, flotation, biomass collection, and adsorption; however, none have been found to be suitable for reasons such as cost effectiveness, long term stability, and selectivity. Recent research has focused on the amidoxime functional group as a promising candidate for uranium sorption. Polymer beads and fibers have been functionalized with amidoxime functional groups, and uranium adsorption capacities as high as 1.5 g U/kg adsorbent have recently been reported with these types of materials. As uranium concentration in seawater is only ~3 ppb, great improvements to uranium collection systems must be made in order to make uranium extraction from seawater economically feasible. This proposed research intends to develop transformative technologies for economic uranium extraction from seawater. The Lin group will design advanced porous supports by taking advantage of recent breakthroughs in nanoscience and nanotechnology and incorporate high densities of well-designed chelators into such nanoporous supports to allow selective and efficient binding of uranyl ions from seawater. Several classes of nanoporous materials, including mesoporous silica nanoparticles (MSNs), mesoporous carbon nanoparticles (MCNs), meta-organic frameworks (MOFs), and covalent-organic frameworks (COFs), will be synthesized. Selective uranium-binding liagnds such as amidoxime will be incorporated into the nanoporous materials to afford a new generation of sorbent materials that will be

  20. Sol-gel derived sorbents

    Sigman, Michael E.; Dindal, Amy B.

    2003-11-11

    Described is a method for producing copolymerized sol-gel derived sorbent particles for the production of copolymerized sol-gel derived sorbent material. The method for producing copolymerized sol-gel derived sorbent particles comprises adding a basic solution to an aqueous metal alkoxide mixture for a pH.ltoreq.8 to hydrolyze the metal alkoxides. Then, allowing the mixture to react at room temperature for a precalculated period of time for the mixture to undergo an increased in viscosity to obtain a desired pore size and surface area. The copolymerized mixture is then added to an immiscible, nonpolar solvent that has been heated to a sufficient temperature wherein the copolymerized mixture forms a solid upon the addition. The solid is recovered from the mixture, and is ready for use in an active sampling trap or activated for use in a passive sampling trap.

  1. Translational and rotational dynamics of water in mesoporous silica materials: MCM-41-S and MCM-48-S

    Faraone, Antonio; Liu Li; Mou, C.-Y.; Shih, P.-C.; Copley, John R.D.; Chen, S.-H.

    2003-01-01

    We investigated the translational and rotational dynamics of water molecules in mesoporous silica materials MCM-41-S and MCM-48-S using the incoherent quasielastic neutron scattering technique. The range of wave vector transfers Q covered in the measurements was from 0.27 to 1.93 Aa -1 broad enough to detect both the translational and rotational contributions to the scattering. We used the relaxing-cage models for both translational and rotational motions which we developed earlier, to analyze the QENS spectra and investigated water dynamics in a supercooled range from 250 to 280 K. The results show a marked slowing down of both the translational and rotational relaxation times, and an increasing effect of confinement on the translational motion, as the temperature is lowered

  2. Novel Shape-Stabilized Phase Change Materials Composed of Polyethylene Glycol/Nonsurfactant-Templated Mesoporous Silica: Preparation and Thermal Properties

    Chen, Yan; Zhu, Yingying; Wang, Jinbao; Lv, Mengjiao; Zhang, Xiongjie; Gao, Junkai; Zhang, Zijun; Lei, Hao

    2017-12-01

    A novel shape-stabilized phase change material (PEG/TAMS), fabricated using tannic acid-templated mesoporous silica (TAMS) as a support for polyethylene glycol, was developed for thermal energy storage. The method used to synthesize TAMS was simple, cost effective, environmentally friendly, and free of surfactant. The characterization results indicated that PEG was physically absorbed to TAMS and that TAMS had no influence on the crystal structure of PEG. According to the TGA thermograms, PEG/TAMS has excellent thermal stability and can be applied over a wide temperature range. Additionally, the differential scanning calorimetry results suggested that PEG/TAMS has good thermal properties and that its fusion and solidification enthalpies reached 114.7 J/g and 102.4 J/g, respectively. The results indicated that PEG/TAMS has great potential for practical applications.

  3. Synthesis and characterization of mesoporous ceria/alumina nanocomposite materials via mixing of the corresponding ceria and alumina gel precursors.

    Khalil, Kamal M S

    2007-03-01

    Mesoporous ceria/alumina, CeO(2)/Al(2)O(3), composites containing 10, 20 and 30% (w/w) ceria were prepared by a novel gel mixing method. In the method, ceria gel (formed via hydrolysis of ammonium cerium(IV) nitrate by aqueous ammonium carbonate solution) and alumina gel (formed via controlled hydrolysis of aluminum tri-isopropoxide) were mixed together. The mixed gel was subjected to subsequent drying and calcination for 3 h at 400, 600, 800 and 1000 degrees C. The uncalcined (dried at 110 degrees C) and the calcined composites were investigated by different techniques including TGA, DSC, FTIR, XRD, SEM and nitrogen adsorption/desorption isotherms. Results indicated that composites calcined for 3 h at 800 degrees C mainly kept amorphous alumina structure and gamma-alumina formed only upon calcinations at 1000 degrees C. On the other hand, CeO(2) was found to crystallize in the common ceria, cerinite, phase and it kept this structure over the entire calcination range (400-1000 degrees C). Therefore, high surface areas, stable surface textures, and non-aggregated nano-sized ceria dispersions were obtained. A systematic texture change based on ceria ratio was observed, however in all cases mesoporous composite materials exposing thermally stable texture and structure were obtained. The presented method produces composite ceria/alumina materials that suit different applications in the field of catalysis and membranes technology, and throw some light on physicochemical factors that determine textural morphology and thermal stability of such important composite.

  4. Novel Sorbent to Clean Up Biogas for CHPs

    Alptekin, Gökhan O. [TDA Research, Incorporated, Wheat Ridge, CO (United States); Jayataman, Ambalavanan [TDA Research, Incorporated, Wheat Ridge, CO (United States); Schaefer, Matthew [TDA Research, Incorporated, Wheat Ridge, CO (United States); Ware, Michael [TDA Research, Incorporated, Wheat Ridge, CO (United States); Hunt, Jennifer [FuelCell Energy, Inc., Danbury, CT (United States); Dobek, Frank [FuelCell Energy, Inc., Danbury, CT (United States)

    2015-05-30

    In this project, TDA Research Inc. (TDA) has developed low-cost (on a per unit volume of gas processed basis), high-capacity expendable sorbents that can remove both the H2S and organic sulfur species in biogas to the ppb levels. The proposed sorbents will operate downstream of a bulk desulfurization system as a polishing bed to provide an essentially sulfur-free gas to a fuel cell (or any other application that needs a completely sulfur-free feed). Our sorbents use a highly dispersed mixed metal oxides active phase with desired modifiers prepared over on a mesoporous support. The support structure allows the large organic sulfur compounds (such as the diethyl sulfide and dipropyl sulfide phases with a large kinetic diameter) to enter the sorbent pores so that they can be adsorbed and removed from the gas stream.

  5. Non-carbon sorbents for mercury removal from flue gases

    Alptekin, G.O.; Dubovik, M.; Cesario, M. [TDA Research Inc., Wheat Ridge, CO (United States)

    2005-07-01

    TDA Research Inc. is developing a new sorbent that can effectively remove mercury from flue gases. It is made of non-carbon based materials and will therefore not alter the properties of the fly ash. The sorbent can be produced as an injectable powder. The paper summarises the initial testing results of the new sorbent. The sorbent exhibited 7.5 to 11.0 mg/g mercury absorption capacity under representative flue gas streams depending on the operating temperature and gas hourly space velocity. The sorbent also showed resistance to sulfur poisoning by sulfur dioxide. 6 refs., 3 figs., 1 tab.

  6. Ultrathin mesoporous Co_3O_4 nanosheets-constructed hierarchical clusters as high rate capability and long life anode materials for lithium-ion batteries

    Wu, Shengming; Xia, Tian; Wang, Jingping; Lu, Feifei; Xu, Chunbo; Zhang, Xianfa; Huo, Lihua; Zhao, Hui

    2017-01-01

    Graphical abstract: Ultrathin mesoporous Co_3O_4 nanosheets-constructed hierarchical clusters (UMCN-HCs) have been successfully synthesized via a facile hydrothermal method followed by a subsequent thermolysis treatment. When tested as anode materials for LIBs, UMCN-HCs achieve high reversible capacity, good long cycling life, and rate capability. - Highlights: • UMCN-HCs show high capacity, excellent stability, and good rate capability. • UMCN-HCs retain a capacity of 1067 mAh g"−"1 after 100 cycles at 100 mA g"−"1. • UMCN-HCs deliver a capacity of 507 mAh g"−"1 after 500 cycles at 2 A g"−"1. - Abstract: Herein, Ultrathin mesoporous Co_3O_4 nanosheets-constructed hierarchical clusters (UMCN-HCs) have been successfully synthesized via a facile hydrothermal method followed by a subsequent thermolysis treatment at 600 °C in air. The products consist of cluster-like Co_3O_4 microarchitectures, which are assembled by numerous ultrathin mesoporous Co_3O_4 nanosheets. When tested as anode materials for lithium-ion batteries, UMCN-HCs deliver a high reversible capacity of 1067 mAh g"−"1 at a current density of 100 mA g"−"1 after 100 cycles. Even at 2 A g"−"1, a stable capacity as high as 507 mAh g"−"1 can be achieved after 500 cycles. The high reversible capacity, excellent cycling stability, and good rate capability of UMCN-HCs may be attributed to their mesoporous sheet-like nanostructure. The sheet-layered structure of UMCN-HCs may buffer the volume change during the lithiation-delithiation process, and the mesoporous characteristic make lithium-ion transfer more easily at the interface between the active electrode and the electrolyte.

  7. Structural and magnetic properties of the nanocomposite materials based on a mesoporous silicon dioxide matrix

    Grigor’eva, N. A., E-mail: natali@lns.pnpi.spb.ru [St. Petersburg State University (Russian Federation); Eckerlebe, H. [Helmholtz-Zentrum Geesthacht (Germany); Eliseev, A. A.; Lukashin, A. V.; Napol’skii, K. S. [Moscow State University (Russian Federation); Kraje, M. [Reactor Institute Delft (Netherlands); Grigor’ev, S. V. [St. Petersburg State University (Russian Federation)

    2017-03-15

    The structural and magnetic properties of the mesoporous systems based on silicon dioxide with a regular hexagonal arrangement of pores several microns in length and several nanometers in diameter, which are filled with iron compound nanofilaments in various chemical states, are studied in detail. The studies are performed using the following mutually complementary methods: transmission electron microscopy, SQUID magnetometry, electron spin resonance, Mössbauer spectroscopy, polarized neutron small-angle diffraction, and synchrotron radiation diffraction. It is shown that the iron nanoparticles in pores are mainly in the γ phase of Fe{sub 2}O{sub 3} with a small addition of the α phase and atomic iron clusters. The effective magnetic field acting on a nanofilament from other nanofilaments is 11 mT and has a dipole nature, the ferromagnetic–paramagnetic transition temperature is in the range 76–94 K depending on the annealing temperature of the samples, and the temperature that corresponds to the change in the magnetic state of the iron oxide nanofilaments is T ≈ 50–60 K at H = 0 and T ≈ 80 K at H = 300 mT. It is also shown that the magnetization reversal of an array of nanofilaments is caused by the magnetostatic interaction between nanofilaments at the fields that are lower than the saturation field.

  8. Immobilization of Lactobacillus rhamnosus in mesoporous silica-based material: An efficiency continuous cell-recycle fermentation system for lactic acid production.

    Zhao, Zijian; Xie, Xiaona; Wang, Zhi; Tao, Yanchun; Niu, Xuedun; Huang, Xuri; Liu, Li; Li, Zhengqiang

    2016-06-01

    Lactic acid bacteria immobilization methods have been widely used for lactic acid production. Until now, the most common immobilization matrix used is calcium alginate. However, Ca-alginate gel disintegrated during lactic acid fermentation. To overcome this deficiency, we developed an immobilization method in which Lactobacillus rhamnosus cells were successfully encapsulated into an ordered mesoporous silica-based material under mild conditions with a high immobilization efficiency of 78.77% by using elemental analysis. We also optimized the cultivation conditions of the immobilized L. rhamnosus and obtained a high glucose conversion yield of 92.4%. Furthermore, L. rhamnosus encapsulated in mesoporous silica-based material exhibited operational stability during repeated fermentation processes and no decrease in lactic acid production up to 8 repeated batches. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  9. Mesoporous amine-bridged polysilsesquioxane for CO2 capture

    Qi, Genggeng

    2011-01-01

    A novel class of amine-supported sorbents based on amine-bridged mesoporous polysilsesquioxane was developed via a simple one-pot sol-gel process. The new sorbent allows the incorporation of a large amount of active groups without sacrificing surface area or pore volume available for CO2 capture, leading to a CO2 capture capacity of 3.2 mmol g−1 under simulated flue gas conditions. The sorbent is readily regenerated at 100°C and exhibits good stability over repetitive adsorption-desorption cycling.

  10. Enhanced thermal properties of novel shape-stabilized PEG composite phase change materials with radial mesoporous silica sphere for thermal energy storage

    Min, Xin; Fang, Minghao; Huang, Zhaohui; Liu, Yan?gai; Huang, Yaoting; Wen, Ruilong; Qian, Tingting; Wu, Xiaowen

    2015-01-01

    Radial mesoporous silica (RMS) sphere was tailor-made for further applications in producing shape-stabilized composite phase change materials (ss-CPCMs) through a facile self-assembly process using CTAB as the main template and TEOS as SiO2 precursor. Novel ss-CPCMs composed of polyethylene glycol (PEG) and RMS were prepared through vacuum impregnating method. Various techniques were employed to characterize the structural and thermal properties of the ss-CPCMs. The DSC results indicated that...

  11. Immobilization of cholesterol esterase in mesoporous silica materials and its hydrolytic activity toward diethyl phthalate

    Orita, Toru, E-mail: nqj45366@nifty.com [Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-cho, Tsu, Mie 514-8570 (Japan); Taiyo Kagaku Co. Ltd., 800 Yamada-cho, Yokkaichi, Mie 512-1111 (Japan); Tomita, Masahiro [Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-cho, Tsu, Mie 514-8570 (Japan); Saito, Takao; Nishida, Nasakazu; Kato, Katsuya [National Institute of Advanced Industrial Science and Technology, 2266-78 Anagahora, Moriyamaku, Nagoya, Aichi 463-8560 (Japan)

    2012-05-01

    Cholesterol esterase (CE, cholesteryl ester hydrolase, EC 3.1.1.13) from porcine pancreas (molecular weight 400-500 kDa) exhibits hydrolytic activity toward various toxic organic phthalate esters. CE was confined in the nanospace (diameter 3-30 nm) of five types of mesoporous silica (MPS) that differ in structural properties such as pore diameter, pore volume, and particle morphology. These structural properties were characterized by transmission electron microscopy, small-angle X-ray diffraction, N{sub 2} adsorption-desorption experiments, solid-state {sup 13}C nuclear magnetic resonance (NMR), and solid-state {sup 29}Si NMR. Catalytic activities of immobilized and free CE were evaluated by the hydrolysis of diethyl phthalate in phosphate buffer solutions containing an organic cosolvent. Optimal activity recovery was achieved when CE was immobilized in n-decane-functionalized MPS, which had a large pore size (22.5 nm). The immobilization also protected against effects of temperature within the range 30 Degree-Sign C-60 Degree-Sign C; CE immobilized in n-decyl-functionalized MPS exhibited better thermal stability than in non-functionalized MPS or free CE. Moreover, it retained approximately 60% of its catalytic activity even after six catalytic cycles. - Highlights: Black-Right-Pointing-Pointer The highest activity of immobilized CE was shown in MPS with a pore size of 22.5 nm. Black-Right-Pointing-Pointer Catalytic efficiency improved when MPS was functionalized by n-decyl substitution. Black-Right-Pointing-Pointer Immobilized CE exhibited good thermal stability and reusability. Black-Right-Pointing-Pointer Organic co-solvent and the substrate structures affected enzyme activities.

  12. Nanoscale materials in chemistry

    Klabunde, Kenneth J; Richards, Ryan

    2009-01-01

    ...: Disordered, Porous Nanostructures Stephanie L. Brock 209 9 Ordered Microporous and Mesoporous Materials Freddy Kleitz 243 10 Applications of Microporous and Mesoporous Materials Anirban Ghosh,...

  13. Mesoporous Silica: A Suitable Adsorbent for Amines

    Abdollahzadeh-Ghom Sara

    2009-01-01

    Full Text Available Abstract Mesoporous silica with KIT-6 structure was investigated as a preconcentrating material in chromatographic systems for ammonia and trimethylamine. Its adsorption capacity was compared to that of existing commercial materials, showing its increased adsorption power. In addition, KIT-6 mesoporous silica efficiently adsorbs both gases, while none of the employed commercial adsorbents did. This means that KIT-6 Mesoporous silica may be a good choice for integrated chromatography/gas sensing micro-devices.

  14. Phenol-formaldehyde carbon with ordered/disordered bimodal mesoporous structure as high-performance electrode materials for supercapacitors

    Cai, Tingwei; Zhou, Min; Han, Guangshuai; Guan, Shiyou

    2013-11-01

    A novel phenol-formaldehyde carbon with ordered/disordered bimodal mesoporous structure is synthesized by the facile evaporation induced self-assembly strategy under a basic aqueous condition with SiO2 particles as template. The prepared bimodal mesoporous carbons (BMCs) are composed of ordered mesoporous and disordered mesoporous with diameter of about 3.5 nm and 7.0 nm, respectively. They can be employed as supercapacitor electrodes in H2SO4 aqueous electrolyte after the simple acid-treatment. BMC exhibits an exceptional specific capacitance of 344 F g-1 at the current density of 0.1 A g-1, although it has a relatively low surface area of 722 m2 g-1. And the BMC electrode displays an excellent cycling stability over 10,000 cycles.

  15. Silica-Silver Nanocomposites as Regenerable Sorbents for Hg0 Removal from Flue Gases.

    Cao, Tiantian; Li, Zhen; Xiong, Yong; Yang, Yue; Xu, Shengming; Bisson, Teresa; Gupta, Rajender; Xu, Zhenghe

    2017-10-17

    Silica-silver nanocomposites (Ag-SBA-15) are a novel class of multifunctional materials with potential applications as sorbents, catalysts, sensors, and disinfectants. In this work, an innovative yet simple and robust method of depositing silver nanoparticles on a mesoporous silica (SBA-15) was developed. The synthesized Ag-SBA-15 was found to achieve a complete capture of Hg 0 at temperatures up to 200 °C. Silver nanoparticles on the SBA-15 were shown to be the critical active sites for the capture of Hg 0 by the Ag-Hg 0 amalgamation mechanism. An Hg 0 capture capacity as high as 13.2 mg·g -1 was achieved by Ag(10)-SBA-15, which is much higher than that achievable by existing Ag-based sorbents and comparable with that achieved by commercial activated carbon. Even after exposure to more complex simulated flue gas flow for 1 h, the Ag(10)-SBA-15 could still achieve an Hg 0 removal efficiency as high as 91.6% with a Hg 0 capture capacity of 457.3 μg·g -1 . More importantly, the spent sorbent could be effectively regenerated and reused without noticeable performance degradation over five cycles. The excellent Hg 0 removal efficiency combined with a simple synthesis procedure, strong tolerance to complex flue gas environment, great thermal stability, and outstanding regeneration capability make the Ag-SBA-15 a promising sorbent for practical applications to Hg 0 capture from coal-fired flue gases.

  16. Evaluation of Cortaderia selloana (Capim-dos-pampas) blankets as sorbent materials for oil spills in simulated hydro equipment; Estudo do desempenho de tecidos e mantas para utilizacao como sorventes para petroleo

    Bonetti, T.F.; Sydenstricker, T.H.D. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil)], e-mail: thais@demec.ufpr.br; Amico, S.C. [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil)

    2006-07-01

    Oil spills in aquatic environments may cause serious economy losses and severe environmental impact which both drive the development of commercial systems (e.g. sorbents) to control these accidents. One way of using sorbents is to encapsulate them with an involucre or cover, i.e. producing blankets. The focus of this research is to evaluate the key characteristics of interest (aerial density, water and oil sorption, mechanical strength and cost) of different materials to use as covers for blankets and to prepare blankets and compare their performance when made with various core materials, such as Cortaderia selloana fibers and different commercial sorbents. A simulated aqueous body with stream was used for the sorption experiments, where the oil and water phases were circulated and forced to pass under the blankets. On the sorption tests, the fibers of Cortaderia selloana reached a performance lower to that of commercial sorbents, mainly due to their low density and high volume (difficult packing), nevertheless a clear trend was noted, heavier blankets with higher sorption periods lead to higher sorption. (author)

  17. Sea urchin-like mesoporous carbon material grown with carbon nanotubes as a cathode catalyst support for fuel cells

    Kuo, Ping-Lin; Hsu, Chun-Han; Li, Wan-Ting; Jhan, Jing-Yi; Chen, Wei-Fu [Department of Chemical Engineering, National Cheng Kung University, Tainan 70101 (China)

    2010-12-15

    A sea urchin-like carbon (UC) material with high surface area (416 m{sup 2} g{sup -1}), adequate electrical conductivity (59.6 S cm{sup -1}) and good chemical stability was prepared by growing carbon nanotubes onto mesoporous carbon hollow spheres. A uniform dispersion of Pt nanoparticles was then anchored on the UC, where the Pt nanoparticles were prepared using benzylamine as the stabilizer. For this Pt loaded carbon, cyclic voltammogram measurements showed an exceptionally high electrochemically active surface area (EAS) (114.8 m{sup 2} g{sup -1}) compared to the commonly used commercial E-TEK catalyst (65.2 m{sup 2} g{sup -1}). The durability test demonstrates that the carbon used as a support exhibited minor loss in EAS of Pt. Compared to the E-TEK (20 wt%) cathode catalyst, this Pt loaded UC catalyst has greatly enhanced catalytic activity toward the oxygen reduction reaction, less cathode flooding and considerably improved performance, resulting in an enhancement of ca. 37% in power density compared with that of E-TEK. Based on the results obtained, the UC is an excellent support for Pt nanoparticles used as cathode catalysts in proton exchange membrane fuel cells. (author)

  18. Facile Synthesis of A 3D Flower-Like Mesoporous Ni@C Composite Material for High-Energy Aqueous Asymmetric Supercapacitors.

    Liu, Song; An, Cuihua; Zang, Lei; Chang, Xiaoya; Guo, Huinan; Jiao, Lifang; Wang, Yijing

    2018-04-16

    A 3D flower-like mesoporous Ni@C composite material has been synthesized by using a facile and economical one-pot hydrothermal method. This unique 3D flower-like Ni@C composite, which exhibited a high surface area (522.4 m 2  g -1 ), consisted of highly dispersed Ni nanoparticles on mesoporous carbon flakes. The effect of calcination temperature on the electrochemical performance of the Ni@C composite was systematically investigated. The optimized material (Ni@C 700) displayed high specific capacity (1306 F g -1 at 2 A g -1 ) and excellent cycling performance (96.7 % retention after 5000 cycles). Furthermore, an asymmetric supercapacitor (ASC) that contained Ni@C 700 as cathode and mesoporous carbon (MC) as anode demonstrated high energy density (60.4 W h kg -1 at a power density of 750 W kg -1 ). © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Self-immobilization of acidogenic mixed consortia on mesoporous material (SBA-15) and activated carbon to enhance fermentative hydrogen production

    Mohan, S. Venkata; Mohanakrishna, G.; Sarma, P.N. [Bioengineering and Environmental Centre, Indian Institute of Chemical Technology, Hyderabad 500607 (India); Reddy, S. Sreevardhan; Raju, B. David; Rao, K.S. Rama [Catalysis and Physical Chemistry Division, Indian Institute of Chemical Technology, Hyderabad 500607 (India)

    2008-11-15

    The influence of self-immobilization of enriched acidogenic mixed consortia on fermentative hydrogen (H{sub 2}) production was studied on different supporting materials [SBA-15 (mesoporous) and activated carbon (granular; GAC and powder; PAC)] using chemical wastewater as substrate. Batch fermentation experiments were performed with same substrate at different organic loading rates (OLRs) under acidophilic microenvironment (pH 5.5) and room temperature (28 {+-} 2 C). Experimental data evidenced the effectiveness of attached growth on both the H{sub 2} yields and substrate degradation efficiency, particularly at higher loading rates. Among the three materials evaluated, immobilization on SBA-15 material showed comparatively effective performance in enhancing both H{sub 2} yield and substrate degradation. Suspended growth (SG-control) culture showed inhibition in terms of both H{sub 2} production and substrate degradation especially at applied higher loading rates. Immobilization on SBA-15 resulted in nine times higher H{sub 2} production (7.29 mol/kg COD{sub R}-day at OLR of 0.83 kg COD/m{sup 3}-day) than the lowest yield observed (suspended growth at OLR of 2.55 kg COD/m{sup 3}-day). Maximum substrate degradation rate (SDR) of 0.96 kg COD/m{sup 3}-day (OLR 2.55 kg COD/m{sup 3}-day) was also observed with SBA-15 immobilization, which is 1.62 times higher than the lowest substrate degradation observed with SG-control experiments with the same OLR. Attached growth on GAC and PAC also showed remarkable improvement in the process performance at higher OLRs compared to SG-control. (author)

  20. Tributyl phosphate removal from reprocessing off-gas streams using a selected sorbent

    Parker, G.B.

    1980-01-01

    Laboratory experiments used small laboratory-scale columns packed with selected sorbent materials to remove tributyl phosphate (TBP) and iodine at conditions approaching those in actual reprocessing off-gas streams. The sorbent materials for TBP removal were placed upstream of iodine sorbent materials to protect the iodine sorbent from the deleterious effects of TBP. Methyl iodide in an airstream containing 30% TBP in normal paraffin hydrocarbons (NPH) and water vapor was metered to two packed columns of sorbents simultaneously (in parallel). One column contained a segment of 8-in. x 14-in. mesh alumina sorbent for TBP removal, the other did not. The measure of the effectiveness of TBP sorbent materials for TBP removal was determined by comparing the iodine retention of the iodine sorbent materials in the two parallel columns. Results from an 18 wt % Ag substituted mordenite iodine sorbent indicated that the iodine retention capacity of the sorbent was reduced 60% by the TBP and that the column containing iodine sorbent material protected by the alumina TBP sorbent retained 30 times more iodine than the column without TBP sorbent. TBP concentration was up to 500 mg/m 3 . Similar experiments using a 7 wt % Ag impregnated silica gel indicated that the TBP vapor had little effect on the iodine retention of the silica gel material. The stoichiometric maximum amount of iodine was retained by the silica gel material. Further experiments were conducted assessing the effects of NO 2 on iodine retention of this 7 wt % Ag sorbent. After the two columns were loaded with iodine in the presence of TBP (in NPH), one column was subjected to 2 vol % NO 2 in air. From visual comparison of the two columns, it appeared that the NO 2 regenerated the silica gel iodine sorbent and that iodine was washed off the silica gel iodine sorbent leaving the sorbent in the original state

  1. Simple test guidelines for screening oilspill sorbents for toxicity

    Blenkinsopp, S.A.; Sergy, G.; Doe, K.; Jackman, P.; Huybers, A.

    1998-01-01

    Environment Canada's Emergencies Science Division has established a program to develop a standard test method suitable for evaluating the toxicity of common sorbent materials. Sorbents are used to absorb or adsorb spilled oil and other hazardous materials. They vary widely in composition and packaging. They are often treated with oleophilic and hydrophobic compounds to improve performance and have been used in large quantities during oil spills. Until now, their potential toxicity has never been considered. Three tests have been evaluated to determine how appropriate they are in screening the toxicity of sorbents. Seven toxicity test recommendations for sorbents were presented. 7 refs., 3 tabs., 2 figs

  2. Desulfurization sorbent regeneration

    Jalan, V.M.; Frost, D.G.

    1982-07-07

    A spent solid sorbent resulting from the removal of hydrogen sulfide from a fuel gas flow is regenerated with a steam-air mixture. The mixture of steam and air may also include additional nitrogen or carbon dioxide. The gas mixture contacts the spent sorbent containing metal sulfide at a temperature above 500/sup 0/C to regenerate the sulfide to metal oxide or carbonate. Various metal species including the period four transition metals and the lanthanides are suitable sorbents that may be regenerated by this method. In addition, the introduction of carbon dioxide gas permits carbonates such as those of strontium, barium and calcium to be regenerated. The steam permits regeneration of spent sorbent without formation of metal sulfate. Moreover, the regeneration will proceed with low oxygen concentrations and will occur without the increase in temperature to minimize the risk of sintering and densification of the sorbent. This method may be used for high-temperature fuel cells.

  3. CO2 Capacity Sorbent Analysis Using Volumetric Measurement Approach

    Huang, Roger; Richardson, Tra-My Justine; Belancik, Grace; Jan, Darrell; Knox, Jim

    2017-01-01

    In support of air revitalization system sorbent selection for future space missions, Ames Research Center (ARC) has performed CO2 capacity tests on various solid sorbents to complement structural strength tests conducted at Marshall Space Flight Center (MSFC). The materials of interest are: Grace Davison Grade 544 13X, Honeywell UOP APG III, LiLSX VSA-10, BASF 13X, and Grace Davison Grade 522 5A. CO2 capacity was for all sorbent materials using a Micromeritics ASAP 2020 Physisorption Volumetric Analysis machine to produce 0C, 10C, 25C, 50C, and 75C isotherms. These data are to be used for modeling data and to provide a basis for continued sorbent research. The volumetric analysis method proved to be effective in generating consistent and repeatable data for the 13X sorbents, but the method needs to be refined to tailor to different sorbents.

  4. Cellular membrane trafficking of mesoporous silica nanoparticles

    Fang, I-Ju [Iowa State Univ., Ames, IA (United States)

    2012-01-01

    This dissertation mainly focuses on the investigation of the cellular membrane trafficking of mesoporous silica nanoparticles. We are interested in the study of endocytosis and exocytosis behaviors of mesoporous silica nanoparticles with desired surface functionality. The relationship between mesoporous silica nanoparticles and membrane trafficking of cells, either cancerous cells or normal cells was examined. Since mesoporous silica nanoparticles were applied in many drug delivery cases, the endocytotic efficiency of mesoporous silica nanoparticles needs to be investigated in more details in order to design the cellular drug delivery system in the controlled way. It is well known that cells can engulf some molecules outside of the cells through a receptor-ligand associated endocytosis. We are interested to determine if those biomolecules binding to cell surface receptors can be utilized on mesoporous silica nanoparticle materials to improve the uptake efficiency or govern the mechanism of endocytosis of mesoporous silica nanoparticles. Arginine-glycine-aspartate (RGD) is a small peptide recognized by cell integrin receptors and it was reported that avidin internalization was highly promoted by tumor lectin. Both RGD and avidin were linked to the surface of mesoporous silica nanoparticle materials to investigate the effect of receptor-associated biomolecule on cellular endocytosis efficiency. The effect of ligand types, ligand conformation and ligand density were discussed in Chapter 2 and 3. Furthermore, the exocytosis of mesoporous silica nanoparticles is very attractive for biological applications. The cellular protein sequestration study of mesoporous silica nanoparticles was examined for further information of the intracellular pathway of endocytosed mesoporous silica nanoparticle materials. The surface functionality of mesoporous silica nanoparticle materials demonstrated selectivity among the materials and cancer and normal cell lines. We aimed to determine

  5. Type I Collagen and Strontium-Containing Mesoporous Glass Particles as Hybrid Material for 3D Printing of Bone-Like Materials.

    Montalbano, Giorgia; Fiorilli, Sonia; Caneschi, Andrea; Vitale-Brovarone, Chiara

    2018-04-28

    Bone tissue engineering offers an alternative promising solution to treat a large number of bone injuries with special focus on pathological conditions, such as osteoporosis. In this scenario, the bone tissue regeneration may be promoted using bioactive and biomimetic materials able to direct cell response, while the desired scaffold architecture can be tailored by means of 3D printing technologies. In this context, our study aimed to develop a hybrid bioactive material suitable for 3D printing of scaffolds mimicking the natural composition and structure of healthy bone. Type I collagen and strontium-containing mesoporous bioactive glasses were combined to obtain suspensions able to perform a sol-gel transition under physiological conditions. Field emission scanning electron microscopy (FESEM) analyses confirmed the formation of fibrous nanostructures homogeneously embedding inorganic particles, whereas bioactivity studies demonstrated the large calcium phosphate deposition. The high-water content promoted the strontium ion release from the embedded glass particles, potentially enhancing the osteogenic behaviour of the composite. Furthermore, the suspension printability was assessed by means of rheological studies and preliminary extrusion tests, showing shear thinning and fast material recovery upon deposition. In conclusion, the reported results suggest that promising hybrid systems suitable for 3D printing of bioactive scaffolds for bone tissue engineering have been developed.

  6. Surface PEGylation of mesoporous silica materials via surface-initiated chain transfer free radical polymerization: Characterization and controlled drug release.

    Huang, Long; Liu, Meiying; Mao, Liucheng; Huang, Qiang; Huang, Hongye; Wan, Qing; Tian, Jianwen; Wen, Yuanqing; Zhang, Xiaoyong; Wei, Yen

    2017-12-01

    As a new type of mesoporous silica materials with large pore diameter (pore size between 2 and 50nm) and high specific surface areas, SBA-15 has been widely explored for different applications especially in the biomedical fields. The surface modification of SBA-15 with functional polymers has demonstrated to be an effective way for improving its properties and performance. In this work, we reported the preparation of PEGylated SBA-15 polymer composites through surface-initiated chain transfer free radical polymerization for the first time. The thiol group was first introduced on SBA-15 via co-condensation with γ-mercaptopropyltrimethoxysilane (MPTS), that were utilized to initiate the chain transfer free radical polymerization using poly(ethylene glycol) methyl ether methacrylate (PEGMA) and itaconic acid (IA) as the monomers. The successful modification of SBA-15 with poly(PEGMA-co-IA) copolymers was evidenced by a series of characterization techniques, including 1 H NMR, FT-IR, TGA and XPS. The final SBA-15-SH- poly(PEGMA-co-IA) composites display well water dispersity and high loading capability towards cisplatin (CDDP) owing to the introduction of hydrophilic PEGMA and carboxyl groups. Furthermore, the CDDP could be released from SBA-15-SH-poly(PEGMA-co-IA)-CDDP complexes in a pH dependent behavior, suggesting the potential controlled drug delivery of SBA-15-SH-poly(PEGMA-co-IA). More importantly, the strategy should be also useful for fabrication of many other functional materials for biomedical applications owing to the advantages of SBA-15 and well monomer adoptability of chain transfer free radical polymerization. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Controlled synthesis of the tricontinuous mesoporous material IBN-9 and its carbon and platinum derivatives

    Zhao, Yunfeng; Zhang, Daliang; Zhao, Lan; Wang, Guangchao; Zhu, Yihan; Cairns, Amy; Sun, Junliang; Zou, Xiaodong; Han, Yu

    2011-01-01

    materials (e.g., carbon and platinum) via a "hard- templating" synthesis route. The obtained carbon material possesses large surface area (∼1900 m2/g), high pore volume (1.56 cm 3/g), and remarkable gas adsorption capability at both cryogenic temperatures

  8. Nitrogen enriched mesoporous organic polymer anchored copper(II) material: an efficient and reusable catalyst for the synthesis of esters and amides from aromatic systems.

    Molla, Rostam Ali; Iqubal, Md Asif; Ghosh, Kajari; Kamaluddin; Islam, Sk Manirul

    2015-04-14

    A new copper-grafted mesoporous poly-melamine-formaldehyde (Cu-mPMF) has been synthesized from melamine and paraformaldehyde in DMSO medium, followed by grafting of Cu(ii) at its surface. Cu-mPMF has been characterized by elemental analysis, powder XRD, HR TEM, FE-SEM, N2 adsorption study, FT-IR, UV-vis DRS, TGA-DTA, EPR spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The Cu-grafted mesoporous material showed very good catalytic activity in methyl esterification of benzylic alcohols and amidation of nitriles. Moreover, the catalyst is easily recoverable and can be reused seven times without appreciable loss of catalytic activity in the above reactions. The highly dispersed and strongly bound Cu(ii) sites in the Cu-grafted mesoporous polymer could be responsible for the observed high activities of the Cu-mPMF catalyst. Due to strong binding with the functional groups of the polymer, no evidence of leached copper from the catalyst during the course of reaction emerged, suggesting true heterogeneity in the catalytic process.

  9. Electroactive mesoporous yttria stabilized zirconia containing platinum or nickel oxide nanoclusters: a new class of solid oxide fuel cell electrode materials

    Mamak, M.; Coombs, N.; Ozin, G.A. [Toronto Univ., ON (Canada). Dept. of Chemistry

    2001-02-01

    The electroactivity of surfactant-templated mesoporous yttria stabilized zirconia, containing nanoclusters of platinum or nickel oxide, is explored by alternating current (AC) complex impedance spectroscopy. The observed oxygen ion and mixed oxygen ion-electron charge-transport behavior for these materials, compared to the sintered-densified non-porous crystalline versions, is ascribed to the unique integration of mesoporosity and nanocrystallinity within the binary and ternary solid solution microstructure. These attributes inspire interest in this new class of materials as candidates for the development of improved performance solid oxide fuel cell electrodes. (orig.)

  10. One-pot hydrothermal synthesis of mesoporous Zn(x)Cd(1-x)S/reduced graphene oxide hybrid material and its enhanced photocatalytic activity.

    Wang, Xinwei; Tian, Hongwei; Cui, Xiaoqiang; Zheng, Weitao; Liu, Yichun

    2014-09-14

    We successfully synthesized mesoporous Zn(x)Cd(1-x)S/reduced graphene oxide (Z(x)CSG) hybrid materials as photocatalysts using a facile one-pot hydrothermal reaction, in which graphene oxide (GO) was easily reduced (RGO), and simultaneously Zn(x)Cd(1-x)S (Z(x)CS) nanoparticles (NPs) with a mesoporous structure were uniformly dispersed on the RGO sheets. By well tuning the band gap from 3.42 to 2.21 eV by changing the molar ratio of Zn/Cd (or Zn content), Z(x)CSG with an optimal zinc content has been found to have a significant absorption in the visible light (VL) region. In addition, under VL irradiation (λ > 420 nm), Z(x)CSG also showed zinc content-dependent photocatalytic efficiencies for the degradation of methylene blue (MB). Our findings are that, among Z(x)CSG, Z(0.4)CSG displayed not only a superior photodegradation efficiency of MB (98%), but also good removal efficiency of total organic carbon (TOC) (67%). Furthermore, Z(0.4)CSG had a high photocatalytic stability, and could be used repeatedly. The enhanced photocatalytic activity for Z(0.4)CSG could be attributed to a synergistic effect between mesoporous Z(x)CS NPs and RGO, including the optimal band gap and the moderate conduction band position for ZxCS (compared to CdS), efficient separation and transfer ability of photogenerated electron/hole pairs in the presence of RGO sheets, and relatively high surface area for both mesoporous Z(x)CS NPs and RGO.

  11. Mesoporous carbon-coated LiFePO4 nanocrystals co-modified with graphene and Mg2+ doping as superior cathode materials for lithium ion batteries.

    Wang, Bo; Xu, Binghui; Liu, Tiefeng; Liu, Peng; Guo, Chenfeng; Wang, Shuo; Wang, Qiuming; Xiong, Zhigang; Wang, Dianlong; Zhao, X S

    2014-01-21

    In this work, mesoporous carbon-coated LiFePO4 nanocrystals further co-modified with graphene and Mg(2+) doping (G/LFMP) were synthesized by a modified rheological phase method to improve the speed of lithium storage as well as cycling stability. The mesoporous structure of LiFePO4 nanocrystals was designed and realized by introducing the bead milling technique, which assisted in forming sucrose-pyrolytic carbon nanoparticles as the template for generating mesopores. For comparison purposes, samples modified only with graphene (G/LFP) or Mg(2+) doping (LFMP) as well as pure LiFePO4 (LFP) were also prepared and investigated. Microscopic observation and nitrogen sorption analysis have revealed the mesoporous morphologies of the as-prepared composites. X-ray diffraction (XRD) and Rietveld refinement data demonstrated that the Mg-doped LiFePO4 is a single olivine-type phase and well crystallized with shortened Fe-O and P-O bonds and a lengthened Li-O bond, resulting in an enhanced Li(+) diffusion velocity. Electrochemical properties have also been investigated after assembling coin cells with the as-prepared composites as the cathode active materials. Remarkably, the G/LFMP composite has exhibited the best electrochemical properties, including fast lithium storage performance and excellent cycle stability. That is because the modification of graphene provided active sites for nuclei, restricted the in situ crystallite growth, increased the electronic conductivity and reduced the interface reaction current density, while, Mg(2+) doping improved the intrinsically electronic and ionic transfer properties of LFP crystals. Moreover, in the G/LFMP composite, the graphene component plays the role of "cushion" as it could quickly realize capacity response, buffering the impact to LFMP under the conditions of high-rate charging or discharging, which results in a pre-eminent rate capability and cycling stability.

  12. Sorbent Scoping Studies

    Chancellor, Christopher John

    2016-01-01

    The Los Alamos National Laboratory-Carlsbad Operations (LANL-CO) office was tasked by the DOE CBFO, Office of the Manager to perform a review of the acceptable knowledge (AK) to identify the oxidizers and sorbents in transuranic (TRU) waste streams, to conduct scoping studies on the oxidizers and sorbents identified in AK review to inform the Quality Level 1 (QL1) testing, and to conduct a series of QL1 tests to provide the scientific data to support a basis of knowledge document for determining the criteria for (1) accepting waste at the Waste Isolation Pilot Plant (WIPP) without treatment, (2) determining waste that will require treatment, and (3) if treatment is required, how the treatment must be performed. The purpose of this report is to present the results of the AK review of sorbents present in active waste streams, provide a technical analysis of the sorbent list, report the results of the scoping studies for the fastest-burning organic sorbent, and provide the list of organic and inorganic sorbents to be used in the development of a Test Plan for Preparation and Testing of Sorbents Mixed with Oxidizer found in Transuranic Waste (DWT-TP-001). The companion report, DWT-RPT-001, Oxidizer Scoping Studies, has similar information for oxidizers identified during the AK review of TRU waste streams. The results of the oxidizer and sorbent scoping studies will be used to inform the QL1 test plan. The QL1 test results will support the development of a basis of knowledge document that will evaluate oxidizing chemicals and sorbents in TRU waste and provide guidance for treatment.

  13. Sorbent Scoping Studies

    Chancellor, Christopher John [Los Alamos National Lab. (LANL), Carlsbad, NM (United States). Difficult Waste Team

    2016-11-14

    The Los Alamos National Laboratory–Carlsbad Operations (LANL-CO) office was tasked by the DOE CBFO, Office of the Manager to perform a review of the acceptable knowledge (AK) to identify the oxidizers and sorbents in transuranic (TRU) waste streams, to conduct scoping studies on the oxidizers and sorbents identified in AK review to inform the Quality Level 1 (QL1) testing, and to conduct a series of QL1 tests to provide the scientific data to support a basis of knowledge document for determining the criteria for (1) accepting waste at the Waste Isolation Pilot Plant (WIPP) without treatment, (2) determining waste that will require treatment, and (3) if treatment is required, how the treatment must be performed. The purpose of this report is to present the results of the AK review of sorbents present in active waste streams, provide a technical analysis of the sorbent list, report the results of the scoping studies for the fastest-burning organic sorbent, and provide the list of organic and inorganic sorbents to be used in the development of a Test Plan for Preparation and Testing of Sorbents Mixed with Oxidizer found in Transuranic Waste (DWT-TP-001). The companion report, DWT-RPT-001, Oxidizer Scoping Studies, has similar information for oxidizers identified during the AK review of TRU waste streams. The results of the oxidizer and sorbent scoping studies will be used to inform the QL1 test plan. The QL1 test results will support the development of a basis of knowledge document that will evaluate oxidizing chemicals and sorbents in TRU waste and provide guidance for treatment.

  14. Improvement of the Derjaguin-Broekhoff-de Boer theory for capillary condensation/evaporation of nitrogen in mesoporous systems and its implications for pore size analysis of MCM-41 silicas and related materials.

    Kowalczyk, Piotr; Jaroniec, Mietek; Terzyk, Artur P; Kaneko, Katsumi; Do, Duong D

    2005-03-01

    In this work, we propose an improvement of the classical Derjaguin-Broekhoff-de Boer (DBdB) theory for capillary condensation/evaporation in mesoporous systems. The primary idea of this improvement is to employ the Gibbs-Tolman-Koenig-Buff equation to predict the surface tension changes in mesopores. In addition, the statistical film thickness (so-called t-curve) evaluated accurately on the basis of the adsorption isotherms measured for the MCM-41 materials is used instead of the originally proposed t-curve (to take into account the excess of the chemical potential due to the surface forces). It is shown that the aforementioned modifications of the original DBdB theory have significant implications for the pore size analysis of mesoporous solids. To verify our improvement of the DBdB pore size analysis method (IDBdB), a series of the calcined MCM-41 samples, which are well-defined materials with hexagonally ordered cylindrical mesopores, were used for the evaluation of the pore size distributions. The correlation of the IDBdB method with the empirically calibrated Kruk-Jaroniec-Sayari (KJS) relationship is very good in the range of small mesopores. So, a major advantage of the IDBdB method is its applicability for small mesopores as well as for the mesopore range beyond that established by the KJS calibration, i.e., for mesopore radii greater than approximately 4.5 nm. The comparison of the IDBdB results with experimental data reported by Kruk and Jaroniec for capillary condensation/evaporation as well as with the results from nonlocal density functional theory developed by Neimark et al. clearly justifies our approach. Note that the proposed improvement of the classical DBdB method preserves its original simplicity and simultaneously ensures a significant improvement of the pore size analysis, which is confirmed by the independent estimation of the mean pore size by the powder X-ray diffraction method.

  15. Synthesis and application of mesoporous molecular sieve for miniaturized matrix solid-phase dispersion extraction of bioactive flavonoids from toothpaste, plant, and saliva.

    Cao, Wan; Cao, Jun; Ye, Li-Hong; Xu, Jing-Jing; Hu, Shuai-Shuai; Peng, Li-Qing

    2015-12-01

    This article describes the use of the mesoporous molecular sieve KIT-6 as a sorbent in miniaturized matrix solid-phase dispersion (MSPD) in combination with ultra-performance LC for the determination of bioactive flavonoids in toothpaste, Scutellariae Radix, and saliva. In this study, for the first time, KIT-6 was used as a sorbent material for this mode of extraction. Compared with common silica-based sorbents (C18 and activated silica gel), the proposed KIT-6 dispersant with a three-dimensional cubic Ia3d structure and highly ordered arrays of mesoporous channels exhibits excellent adsorption capability of the tested compounds. In addition, several experimental variables, such as the mass ratio of sample to dispersant, grinding time, and elution solvent, were optimized to maximize the extraction efficiency. The proposed analytical method is simple, fast, and entails low consumption of samples, dispersants and elution solvents, thereby meeting "green chemistry" requirements. Under the optimized conditions, the recoveries of three bioactive flavonoids obtained by analyzing the spiked samples were from 89.22 to 101.17%. Also, the LODs and LOQs for determining the analytes were in the range of 0.02-0.04 μg/mL and 0.07-0.13 μg/mL, respectively. Finally, the miniaturized matrix solid-phase dispersion method was successfully applied to the analysis of target solutes in real samples, and satisfactory results were obtained. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Thermal decomposition pathway of undoped and doped zinc layered gallate nanohybrid with Fe 3+, Co 2+ and Ni 2+ to produce mesoporous and high pore volume carbon material

    Ghotbi, Mohammad Yeganeh; bin Hussein, Mohd Zobir; Yahaya, Asmah Hj; Abd Rahman, Mohd Zaki

    2009-12-01

    A series of brucite-like materials, undoped and doped zinc layered hydroxide nitrate with 2% (molar) Fe 3+, Co 2+ and Ni 2+ were synthesized. Organic-inorganic nanohybrid material with gallate anion as a guest, and zinc hydroxide nitrate, as an inorganic layered host was prepared by the ion-exchange method. The nanohybrid materials were heat-treated at various temperatures, 400-700 °C. X-ray diffraction, thermal analysis and also Fourier transform infrared results showed that incorporation of the doping agents within the zinc layered hydroxide salt layers has enhanced the heat-resistivity of the nanohybrid materials in the thermal decomposition pathway. Porous carbon materials can be obtained from the heat-treating the nanohybrids at 600 and 700 °C. Calcination of the nanohybrids at 700 °C under nitrogen atmosphere produces mesoporous and high pore volume carbon materials.

  17. Sorbent selection and design considerations for uranium trapping

    Schultz, R.M.; Hobbs, W.E.; Norton, J.L.; Stephenson, M.J.

    1981-07-01

    The efficient removal of UF 6 from effluent streams can be accomplished through the selection of the best solid sorbent and the implementation of good design principles. Pressure losses, sorbent capacity, reaction kinetics, sorbent regeneration/uranium recovery requirements and the effects of other system components are the performance factors which are summarized. The commonly used uranium trapping materials highlighted are sodium fluoride, H-151 alumina, XF-100 alumina, and F-1 alumina. Sorbent selection and trap design have to be made on a case-by-case basis but the theoretical modeling studies and the evaluation of the performance factors presented can be used as a guide for other chemical trap applications

  18. Characterization of mesoporous VOx/MCM-41 composite materials obtained via post-synthesis impregnation

    Bukallah, Saeed B.; Bumajdad, Ali; Khalil, Kamal M.S.; Zaki, Mohamed I.

    2010-01-01

    Spherical-particle MCM-41 was synthesized at room temperature, and, then, impregnated with aqueous solutions of NH 4 VO 3 to produce variously loaded VO x /MCM-41 composite materials. Bulk and surface properties of the materials thus produced were characterized by means of X-ray powder diffractometry (XRD), infrared spectroscopy (FTIR), N 2 sorptiometry and X-ray photoelectron spectroscopy (XPS). Results obtained indicated that subsequent calcination at 550 deg. C (for 2 h) of the blank and impregnated MCM-41 particles, results in materials assuming the same bulk structure of MCM-41, and exposing uniformly mesporous, high area surfaces (P w = 2.0-2.3 nm; 974-829 m 2 /g), except for the material obtained at 20 wt%-V 2 O 5 that was shown to suffer a considerable loss on surface area (down to 503 m 2 /g). XPS results implied that the immobilization of the VO x species occurs via interaction with surface OH/H 2 O groups of MCM-41, leading to the formation of vanadate (VO 3 - ) surface species, as well as minor V-O-Si and V 2 O 5 -like species. However, in all cases, the vanadium sites remained pentavalent and exposed on the surface.

  19. Solid-phase extraction of the alcohol abuse biomarker phosphatidylethanol using newly synthesized polymeric sorbent materials containing quaternary heterocyclic groups.

    Duarte, Mariana; Jagadeesan, Kishore Kumar; Billing, Johan; Yilmaz, Ecevit; Laurell, Thomas; Ekström, Simon

    2017-10-13

    Phosphatidylethanol (PEth) is an interesting biomarker finding increased use for detecting long term alcohol abuse with high specificity and sensitivity. Prior to detection, sample preparation is an unavoidable step in the work-flow of PEth analysis and new protocols may facilitate it. Solid-phase extraction (SPE) is a versatile sample preparation method widely spread in biomedical laboratories due to its simplicity of use and the possibility of automation. In this work, SPE was used for the first time to directly extract PEth from spiked human plasma and spiked human blood. A library of polymeric SPE materials with different surface functionalities was screened for PEth extraction in order to identify the surface characteristics that control PEth retention and recovery. The plasma samples were diluted 1:10 (v/v) in water and spiked at different concentrations ranging from 0.3 to 5μM. The library of SPE materials was then evaluated using the proposed SPE method and detection was done by LC-MS/MS. One SPE material efficiently retained and recovered PEth from spiked human plasma. With this insight, four new SPE materials were formulated and synthesized based on the surface characteristics of the best SPE material found in the first screening. These new materials were tested with spiked human blood, to better mimic a real clinical sample. All the newly synthetized materials outperformed the pre-existing commercially available materials. Recovery values for the new SPE materials were found between 29.5% and 48.6% for the extraction of PEth in spiked blood. A material based on quaternized 1-vinylimidazole with a poly(trimethylolpropane trimethacrylate) backbone was found suitable for PEth extraction in spiked blood showing the highest analyte recovery in this experiment, 48.6%±6.4%. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Plutonium sorption to nanocast mesoporous carbon

    Parsons-Moss, Tashi; Wang, Deborah; Jones, Stephen; Olive, Daniel; Nitsche, Heino [California Univ., Berkeley, CA (United States). Dept. of Chemistry; Lawrence Berkeley National Laboratory, Berkeley, CA (United States). Nuclear Science Div.; Tueysuez, Harun [Lawrence Berkeley National Laboratory, Berkeley, CA (United States). Nuclear Science Div.; Max-Planck-Institut fuer Kohlenforschung, Muelheim an der Ruhr (Germany)

    2014-09-01

    Nanocast ordered mesoporous carbons are attractive as sorbents because of their extremely high surface areas and large pore volumes. This paper compares Pu uptake, added as Pu(VI), to both untreated and chemically oxidized CMK-(carbon molecular sieves from KAIST) type mesoporous carbon with that to a commercial amorphous activated carbon. The CMK was synthesized via nanocasting by using cubic ordered mesoporous silica KIT-6 as a hard template, and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption. A portion of the CMK was oxidized by treatment with nitric acid, and will be called OX CMK. The three carbon powders have similar particle morphology, and high BET surface areas. The activated carbon is disordered, while the CMK materials show large domains of ordered cubic mesostructure. The CMK material seems to have more oxygen-containing functional groups than the activated carbon, and the oxidation of the CMK increased the density of these groups, especially - COOH, thus lowering the point of zero charge (PZC) of the material. Batch studies of all 3 materials with plutonium solutions, in a 0.1 M NaClO{sub 4} matrix were performed to investigate pH dependence, sorption kinetics, Pu uptake capacities, competition with ethylenediaminetetraacetic acid (EDTA) in solution, and Pu desorption. Both CMK materials demonstrated high Pu sorption from solutions of pH 3 or greater, and the oxidized CMK also showed high sorption from pH 2 solutions. The activated carbon bound less Pu, and at a much slower rate than CMK. All other batch experiments were carried out in pH 4 solutions. The Pu uptake from low-concentration solutions was faster for the oxidized CMK than for untreated CMK, but in more concentrated samples (∝ 250 μM Pu), the Pu uptake kinetics and apparent capacity were the same for oxidized and untreated CMK. The 23-h Pu uptake capacity of the CMK

  1. Gold and palladium adsorption from leached electronic scrap using ordered mesoporous carbon nanoscaffolds

    McDowell, Rocklan; Dutech, Guy

    2014-09-01

    Ordered mesoporous carbon (OMC) nanoscaffolds are engineered agglomerates of carbon nanotubes held together by small carbon nanofibers with uniform pore sizes, high pore volume, and high channel permeability. These materials exhibit very high affinity for the adsorption of gold from aqueous acidic mixtures. The efficiency of gold recovery is comparable to those typically accomplished using biopolymer-based adsorbents. The adsorption efficiency for other precious metals such as palladium and platinum is lower. Studies on the precious metal (Au, Pd) adsorption on OMC materials from actual liquors of leached electronics will be presented. Adsorption properties will be compared for several different sorbents used for the recovery of precious metals. The leach liquor compositions for three different types of electronic scrap materials (personal computer board, cell phone and tv input/output board) will be presented. The sorption efficiencies for Au, Pd, together with a spectrum of competing and non-competing metals, from such leach mixtures will be compared.

  2. Gold and palladium adsorption from leached electronic scrap using ordered mesoporous carbon nanoscaffolds

    McDowell, Rocklan; Dutech, Guy

    2014-01-01

    Ordered mesoporous carbon (OMC) nanoscaffolds are engineered agglomerates of carbon nanotubes held together by small carbon nanofibers with uniform pore sizes, high pore volume, and high channel permeability. These materials exhibit very high affinity for the adsorption of gold from aqueous acidic mixtures. The efficiency of gold recovery is comparable to those typically accomplished using biopolymer-based adsorbents. The adsorption efficiency for other precious metals such as palladium and platinum is lower. Studies on the precious metal (Au, Pd) adsorption on OMC materials from actual liquors of leached electronics will be presented. Adsorption properties will be compared for several different sorbents used for the recovery of precious metals. The leach liquor compositions for three different types of electronic scrap materials (personal computer board, cell phone and tv input/output board) will be presented. The sorption efficiencies for Au, Pd, together with a spectrum of competing and non-competing metals, from such leach mixtures will be compared.

  3. A multi-controlled drug delivery system based on magnetic mesoporous Fe3O4 nanopaticles and a phase change material for cancer thermo-chemotherapy

    Zhang, Qi; Liu, Jian; Yuan, Kunjie; Zhang, Zhengguo; Zhang, Xiaowen; Fang, Xiaoming

    2017-10-01

    Herein a novel multi-controlled drug release system for doxorubicin (DOX) was developed, in which monodisperse mesoporous Fe3O4 nanoparticles were combined with a phase change material (PCM) and polyethylene glycol 2000 (PEG2000). It is found that the PCM/PEG/DOX mixture containing 20% PEG could be dissolved into water at 42 °C. The mesoporous Fe3O4 nanoparticles prepared by the solvothermal method had sizes of around 25 nm and exhibited a mesoporous microstructure. A simple solvent evaporation process was employed to load the PCM/PEG/DOX mixture on the mesoporous Fe3O4 nanoparticles completely. In the Fe3O4@PCM/PEG/DOX system, the pores of the Fe3O4 nanoparticles were observed to be filled with the mixture of PCM/PEG/DOX. The Fe3O4@PCM/PEG/DOX system showed a saturation magnetization value of 50.0 emu g-1, lower than 71.1 emu g-1 of the mesoporous Fe3O4 nanoparticles, but it was still high enough for magnetic targeting and hyperthermia application. The evaluation on drug release performance indicated that the Fe3O4@PCM/PEG/DOX system achieved nearly zero release of DOX in vitro in body temperature, while around 80% of DOX could be released within 1.5 h at the therapeutic threshold of 42 °C or under the NIR laser irradiation for about 4 h. And a very rapid release of DOX was achieved by this system when applying an alternating magnetic field. By comparing the systems with and without PEG2000, it is revealed that the presence of PEG2000 makes DOX easy to be released from 1-tetradecanol to water, owing to its functions of increasing the solubility of DOX in 1-tetradecanol as well as decreasing the surface tension between water and 1-tetradecanol. The novel drug release system shows great potential for the development of thermo-chemotherapy of cancer treatment.

  4. Development of TRPN dendrimer-modified disordered mesoporous silica for CO{sub 2} capture

    Zhang, Xiaoyun; Zhang, Sisi; Qin, Hongyan; Wu, Wei, E-mail: wuweiupc@upc.edu.cn

    2014-08-15

    Highlights: • A novel series of TRPN dendrimers are synthesized. • Structurally disordered mesoporous silica was used to develop the CO{sub 2} adsorbent. • The CO{sub 2} adsorption capacity is relatively high. • The sorbent exhibits a high stability after 12 cycling runs. • The sorbent achieves complete desorption at low temperature (60 °C). - Abstract: A novel series of tri(3-aminopropyl) amine (TRPN) dendrimers were synthesized and impregnated on structurally disordered mesoporous silica (DMS) to generate CO{sub 2} adsorbents (TS). The physicochemical and adsorption properties of the adsorbents before and after dendrimer modification were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and N{sub 2} adsorption–desorption (N{sub 2}-BET) techniques. CO{sub 2} adsorption–desorption tests indicated that the sorbent demonstrates high CO{sub 2} adsorption capacity (138.1 mg g{sup −1} for G1 sample TS-G1-3CN-50 and 91.7 mg g{sup −1} for G2 sample TS-G2-6CN-50), and can completely desorb CO{sub 2} under vacuum at 60 °C. Its CO{sub 2} adsorption capacity at 25 °C increases with the amine loading, achieving the highest adsorption capacity (140.6 mg g{sup −1} for TS-G1-3CN) at 60%. The developed TS materials exhibited excellent cycling stability. After 12 consecutive adsorption–desorption runs, TS-G1-3CN-50 shows an adsorption capacity of 136.0 mg g{sup −1}, retaining 98.5% of its original value.

  5. Mesoporous binary metal oxide nanocomposites: Synthesis, characterization and decontamination of sulfur mustard

    Praveen Kumar, J., E-mail: praveenjella10@gmail.com; Prasad, G.K.; Ramacharyulu, P.V.R.K.; Singh, Beer; Gopi, T.; Krishna, R.

    2016-04-15

    Mesoporous MnO{sub 2}–ZnO, Fe{sub 2}O{sub 3}–ZnO, NiO–ZnO, and CeO{sub 2}–ZnO binary metal oxide nanocomposites were studied as sorbent decontaminants against sulfur mustard. They were synthesized by precipitation pyrolysis method and characterized by means of transmission electron microscopy, scanning electron microscopy coupled with energy dispersive analysis of X rays, X ray diffraction, and nitrogen adsorption techniques. The transmission electron microscopy and nitrogen adsorption data indicated the presence of pores with diameter ranging from 10 to 70 nm in the binary metal oxide nanocomposites and these materials exhibited surface area values in the range of 76–134 m{sup 2}/g. These binary metal oxide nanocomposites demonstrated large decontamination efficiencies against sulfur mustard when compared to their single component metal oxide nanoparticles. The binary metal oxide nanocomposites effectively decontaminated sulfur mustard into relatively non toxic products such as chloro ethyl vinyl sulfide, divinyl sulfide, 1,4-oxathiane, etc. The promising decontamination properties of binary metal oxide nanocomposites against sulfur mustard were attributed to the basic sites, Lewis acid sites, and the presence of these sites was confirmed by CO{sub 2} and NH{sub 3} temperature programmed desorption. - Graphical abstract: Mesoporous MnO{sub 2}–ZnO, Fe{sub 2}O{sub 3}–ZnO, NiO–ZnO, and CeO{sub 2}–ZnO binary metal oxide nanocomposites were studied as sorbent decontaminants against sulfur mustard. - Highlights: • Binary metal oxide nanocomposites were synthesized by co-precipitation method. • They were studied as sorbent decontaminants against sulfur mustard. • They decontaminated sulfur mustard into non toxic products. • MnO{sub 2}–ZnO and CeO{sub 2}–ZnO nanocomposites showed greater decontamination efficiency.

  6. Catalytic Activity of Cobalt Grafted on Ordered Mesoporous Silica Materials in N2O Decomposition and CO Oxidation.

    Kuboňová, L.; Peikertová, P.; Mamulová Kutláková, K.; Jirátová, Květa; Słowik, G.; Obalová, L.; Cool, P.

    2017-01-01

    Roč. 437, AUG 2017 (2017), s. 57-72 ISSN 2468-8231 R&D Projects: GA ČR GA14-13750S Institutional support: RVO:67985858 Keywords : mesoporous ordered silica * cobalt * N2O decomposition Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering

  7. Cyclic voltammetry modeling of proton transport effects on redox charge storage in conductive materials: application to a TiO2 mesoporous film.

    Kim, Y S; Balland, V; Limoges, B; Costentin, C

    2017-07-21

    Cyclic voltammetry is a particularly useful tool for characterizing charge accumulation in conductive materials. A simple model is presented to evaluate proton transport effects on charge storage in conductive materials associated with a redox process coupled with proton insertion in the bulk material from an aqueous buffered solution, a situation frequently encountered in metal oxide materials. The interplay between proton transport inside and outside the materials is described using a formulation of the problem through introduction of dimensionless variables that allows defining the minimum number of parameters governing the cyclic voltammetry response with consideration of a simple description of the system geometry. This approach is illustrated by analysis of proton insertion in a mesoporous TiO 2 film.

  8. Solid amine sorbents for CO2 capture by chemical adsorption: A review

    Elif Erdal Ünveren

    2017-03-01

    Full Text Available Amines are well-known for their reversible reactions with CO2, which make them ideal for CO2 capture from several gas streams, including flue gas. In this respect, selective CO2 absorption by aqueous alkanolamines is the most mature technology but the process is energy intensive and has also corrosion problems. Both disadvantages can be diminished to a certain extent by chemical adsorption of CO2 selectively. The most important element of the chemical adsorption of CO2 involves the design and development of a suitable adsorbent which consist of a porous support onto which an amine is attached or immobilized. Such an adsorbent is often called as solid amine sorbent. This review covers solid amine-based studies which are developed and published in recent years. First, the review examines several different types of porous support materials, namely, three mesoporous silica (MCM-41, SBA-15 and KIT-6 and two polymeric supports (PMMA and PS for CO2 adsorption. Emphasis is given to the synthesis, modifications and characterizations -such as BET and PXRD data-of them. Amination of these supports to obtain a solid amine sorbent through impregnation or grafting is reviewed comparatively. Focus is given to the adsorption mechanisms, material characteristics, and synthesis methods which are discussed in detail. Significant amount of original data are also presented which makes this review unique. Finally, relevant CO2 adsorption (or equilibrium capacity data, and cyclic adsorption/desorption performance and stability of important classes of solid amine sorbents are critically reviewed. These include severa PEI or TEPA impregnated adsorbents and APTES-grafted systems.

  9. The Synthesis, Characterization and Catalytic Reaction Studies of Monodisperse Platinum Nanoparticles in Mesoporous Oxide Materials

    Rioux, Robert M. [Univ. of California, Berkeley, CA (United States)

    2006-01-01

    A catalyst design program was implemented in which Pt nanoparticles, either of monodisperse size and/or shape were synthesized, characterized and studied in a number of hydrocarbon conversion reactions. The novel preparation of these materials enables exquisite control over their physical and chemical properties that could be controlled (and therefore rationally tuned) during synthesis. The ability to synthesize rather than prepare catalysts followed by thorough characterization enable accurate structure-function relationships to be elucidated. This thesis emphasizes all three aspects of catalyst design: synthesis, characterization and reactivity studies. The precise control of metal nanoparticle size, surface structure and composition may enable the development of highly active and selective heterogeneous catalysts.

  10. Ionic Liquid Directed Mesoporous Carbon Nanoflakes as an Effiencient Electrode material

    Kong, Lirong; Chen, Wei

    2015-12-01

    Supercapacitors are considered to be the most promising approach to meet the pressing requirements for energy storage devices. The electrode materials for supercapacitors have close relationship with their electrochemical properties and thus become the key point to improve their energy storage efficiency. Herein, by using poly (vinylidene fluoride-co-hexafluoropropylene) and ionic liquid as the dual templates, polyacrylonitrile as the carbon precursor, a flake-like carbon material was prepared by a direct carbonization method. In this method, poly (vinylidene fluoride-co-hexafluoropropylene) worked as the separator for the formation of isolated carbon flakes while aggregated ionic liquid worked as the pore template. The obtained carbon flakes exhibited a specific capacitance of 170 F/g at 0.1 A/g, a high energy density of 12.2 Wh/kg and a high power density of 5 kW/kg at the current of 10 A/g. It also maintained a high capacitance retention capability with almost no declination after 500 charge-discharge cycles. The ionic liquid directed method developed here also provided a new idea for the preparation of hierarchically porous carbon nanomaterials.

  11. UTILIZATION OF RICE HUSK AS RAW MATERIAL IN SYNTHESIS OF MESOPOROUS SILICATES MCM-41

    Suyanta Suyanta

    2011-12-01

    Full Text Available The research about synthesis and characterization of MCM-41 from rice husk has been done. Silica (SiO2 was extracted from rice husk by refluxing with 3M hydrochloric solution at 80 °C for 3 h. The acid-leached rice husk was filtered, washed, dried and calcined at 650 °C for 6 h lead the rough powder of rice husk silica with light brown in color. Characterization was carried out by X-ray diffraction (XRD and FTIR spectroscopy method. Rice husk silica was dissolved into the sodium hydroxide solution leading to the solution of sodium silicate, and used as silica source for the synthesis of MCM-41. MCM-41 was synthesized by hydrothermal process to the mixture prepared from 29 g of distilled water, 8.67 g of cetyltrimethyl ammonium bromide (CTMAB, 9.31 g of sodium silicate solution, and amount mL of 1 M H2SO4. Hydrothermal process was carried out at 100 °C in a teflon-lined stainless steel autoclave heated in the oven for 36 h. The solid phase was filtered, then washed with deionised water, and dried in the oven at 100 °C for 2 h. The surfactant CTMAB was removed by calcination at 550 °C for 10 h with heating rate 2 °C/min. The as-synthesized and calcined crystals were characterized by using FTIR spectroscopy, X-ray diffraction and N2 physisorption methods. In order to investigate the effect of silica source, the same procedure was carried out by using pure sodium silicate as silica source. It was concluded that silica extracted from rice husk can be used as raw materials in the synthesis of MCM-41, there is no significant difference in crystallinity and pore properties when was compared to material produced from commercial sodium silicate.

  12. Post combustion carbon capture - solid sorbents and membranes

    Davidson, R.M. [IEA Clean Coal Centre, London (United Kingdom)

    2009-04-15

    This report follows on from that on solvent scrubbing for post-combustion carbon capture from coal-fired power plants by considering the use of solid sorbents and membranes instead of solvents. First, mesoporous and microporous adsorbents are discussed: carbon-based adsorbents, zeolites, hydrotalcites and porous crystals. Attempts have been made to improve the performance of the porous adsorbent by functionalising them with nitrogen groups and specifically, amine groups to react with CO{sub 2} and thus enhance the physical adsorption properties. Dry, regenerable solid sorbents have attracted a good deal of research. Most of the work has been on the carbonation/calcination cycle of natural limestone but there have also been studies of other calcium-based sorbents and alkali metal-based sorbents. Membranes have also been studied as potential post-combustion capture devices. Finally, techno-economic studies predicting the economic performance of solid sorbents and membranes are discussed. The report is available from IEA Clean Coal Centre as report no. CCC/144. See Coal Abstracts entry April 2009 00406. 340 refs., 21 figs., 8 tabs.

  13. Novel sponge-like molecularly imprinted mesoporous silica material for selective isolation of bisphenol A and its analogues from sediment extracts

    Yang, Jiajia [Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Yun; Wang, Jincheng [Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); Sun, Xiaoli [Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Shah, Syed Mazhar [Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); Cao, Rong [Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Chen, Jiping, E-mail: chenjp@dicp.ac.cn [Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China)

    2015-01-01

    Highlights: • Novel sponge-like molecularly imprinted mesoporous silica was synthesized. • Extraordinarily large specific surface area and highly interconnected 3-D porous network. • High specific adsorption capacity and fast adsorption kinetics for BPA. • Good class-selectivity and clean-up effect for bisphenols in sediment under SPE mode. • Good recoveries and sensitivity for bisphenols using the MISMS–SPE coupled with HPLC–DAD method. - Abstract: Bisphenol A (BPA) imprinted sponge mesoporous silica was synthesized using a combination of semi-covalent molecular imprinting and simple self-assembly process. The molecularly imprinted sponge mesoporous silica (MISMS) material obtained was characterized by FT-IR, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption–desorption measurements. The results show that the MISMS possessed a large specific surface area (850.55 m{sup 2} g{sup −1}) and a highly interconnected 3-D porous network. As a result, the MISMS demonstrated a superior specific adsorption capacity of 169.22 μmol g{sup −1} and fast adsorption kinetics (reaching equilibrium within 3 min) for BPA. Good class selectivity for BPA and its analogues (bisphenol F, bisphenol B, bisphenol E and bisphenol AF) was also demonstrated by the sorption experiment. The MISMS as solid-phase extraction (SPE) material was then evaluated for isolation and clean-up of these bisphenols (BPs) from sediment samples. An accurate and sensitive analytical method based on the MISMS–SPE coupled with HPLC–DAD has been successfully established for simultaneous determination of five BPs in river sediments with detection limits of 0.43–0.71 ng g{sup −1} dry weight (dw). The recoveries of BPs for lyophilizated sediment samples at two spiking levels (50 and 500 ng g{sup −1} dw for each BP) were in the range of 75.5–105.5% with RSD values below 7.5%.

  14. Novel sponge-like molecularly imprinted mesoporous silica material for selective isolation of bisphenol A and its analogues from sediment extracts

    Yang, Jiajia; Li, Yun; Wang, Jincheng; Sun, Xiaoli; Shah, Syed Mazhar; Cao, Rong; Chen, Jiping

    2015-01-01

    Highlights: • Novel sponge-like molecularly imprinted mesoporous silica was synthesized. • Extraordinarily large specific surface area and highly interconnected 3-D porous network. • High specific adsorption capacity and fast adsorption kinetics for BPA. • Good class-selectivity and clean-up effect for bisphenols in sediment under SPE mode. • Good recoveries and sensitivity for bisphenols using the MISMS–SPE coupled with HPLC–DAD method. - Abstract: Bisphenol A (BPA) imprinted sponge mesoporous silica was synthesized using a combination of semi-covalent molecular imprinting and simple self-assembly process. The molecularly imprinted sponge mesoporous silica (MISMS) material obtained was characterized by FT-IR, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption–desorption measurements. The results show that the MISMS possessed a large specific surface area (850.55 m 2 g −1 ) and a highly interconnected 3-D porous network. As a result, the MISMS demonstrated a superior specific adsorption capacity of 169.22 μmol g −1 and fast adsorption kinetics (reaching equilibrium within 3 min) for BPA. Good class selectivity for BPA and its analogues (bisphenol F, bisphenol B, bisphenol E and bisphenol AF) was also demonstrated by the sorption experiment. The MISMS as solid-phase extraction (SPE) material was then evaluated for isolation and clean-up of these bisphenols (BPs) from sediment samples. An accurate and sensitive analytical method based on the MISMS–SPE coupled with HPLC–DAD has been successfully established for simultaneous determination of five BPs in river sediments with detection limits of 0.43–0.71 ng g −1 dry weight (dw). The recoveries of BPs for lyophilizated sediment samples at two spiking levels (50 and 500 ng g −1 dw for each BP) were in the range of 75.5–105.5% with RSD values below 7.5%

  15. Al-doped TiO{sub 2} mesoporous material supported Pd with enhanced catalytic activity for complete oxidation of ethanol

    Zhu, Jing, E-mail: mlczjsls123@163.com; Mu, Wentao, E-mail: mwt15035687833@163.com; Su, Liqing, E-mail: suliqing0163@163.com; Li, Xingying, E-mail: lixingying0479@link.tyut.edu.cn; Guo, Yuyu, E-mail: guoyuyu0455@link.tyut.edu.cn; Zhang, Shen, E-mail: zhangshen0472@link.tyut.edu.cn; Li, Zhe, E-mail: lizhe@tyut.edu.cn

    2017-04-15

    Pd catalysts supported on Al-doped TiO{sub 2} mesoporous materials were evaluated in complete oxidation of ethanol. The catalysts synthesized by wet impregnation based on evaporation-induced self-assembly were characterized by X-ray diffraction, measurement of pore structure, XPS, FT-IR, temperature programmed reduction and TEM. Characteristic results showed that the aluminium was doped into the lattice of mesoporous anatase TiO{sub 2} to form Al-O-Ti defect structure. Catalytic results revealed that Al-doped catalysts were much more active than the pristine one, especially at low temperature (≤200 °C). This should be ascribed to the introduction of aluminium ions that suppressed the strong metal-support interaction and increased the active sites of Pd oxides, enhanced the stabilized anatase TiO{sub 2}, improved well dispersed high valence palladium species with high reducibility and enriched chemisorption oxygen. - Graphical abstract: Al-doped Pd/TiO{sub 2} exhibited optimal catalytic performance for ethanol oxidation and CO{sub 2} yield by the suppression of SMSI. - Highlights: • Palladium catalysts supported on Al-doped TiO{sub 2} mesoporous materials were studied. • The introduction of Al can enhance anatase stabilization and increase defect TiO{sub 2}. • The Pd/Al-TiO{sub 2} catalysts show higher ethanol conversion and CO{sub 2} yield than Pd/TiO{sub 2}. • The influence of Al on SMSI and catalytic performance were evaluated by TPR and XPS.

  16. A green strategy for lithium isotopes separation by using mesoporous silica materials doped with ionic liquids and benzo-15-crown-5

    Wen Zhou; Xiao-Li Sun; Lin Gu; Fei-Fei Bao; Xin-Xin Xu; Chun-Yan Pang; Zaijun Li; Zhi-Guo Gu; Jiangnan University, Wuxi

    2014-01-01

    Three new mesoporous silica materials IL15SGs (HF15SG, TF15SG and DF15SG) doped with benzo-15-crown-5 and imidazolium based ionic liquids (C 8 mim + PF 6 - , C 8 mim + BF 4 - or C 8 mim + NTf 2 - ) have been prepared by a simple approach to separating lithium isotopes. The formed mesoporous structures of silica gels have been confirmed by transmission electron microscopy image and N 2 gas adsorption-desorption isotherm. Imidazolium ionic liquids acted as templates to prepare mesoporous materials, additives to stabilize extractant within silica gel, and synergetic agents to separate the lithium isotopes. Factors such as lithium salt concentration, initial pH, counter anion of lithium salt, extraction time, and temperature on the lithium isotopes separation were examined. Under optimized conditions, the extraction efficiency of HF15SG, TF15SG and DF15SG were found to be 11.43, 10.59 and 13.07 %, respectively. The heavier isotope 7 Li was concentrated in the solution phase while the lighter isotope 6 Li was enriched in the gel phase. The solid-liquid extraction maximum single-stage isotopes separation factor of 6 Li- 7 Li in the solid-liquid extraction was up to 1.046 ± 0.002. X-ray crystal structure analysis indicated that the lithium salt was extracted into the solid phase with crown ether forming [(Li 0.5 ) 2 (B 15 ) 2 (H 2 O)] + complexes. IL15SGs were also easily regenerated by stripping with 20 mmol L -1 HCl and reused in the consecutive removal of lithium ion in five cycles. (author)

  17. Synthesis of Hierarchically Structured Hybrid Materials by Controlled Self-Assembly of Metal-Organic Framework with Mesoporous Silica for CO2 Adsorption.

    Chen, Chong; Li, Bingxue; Zhou, Lijin; Xia, Zefeng; Feng, Nengjie; Ding, Jing; Wang, Lei; Wan, Hui; Guan, Guofeng

    2017-07-12

    The HKUST-1@SBA-15 composites with hierarchical pore structure were constructed by in situ self-assembly of metal-organic framework (MOF) with mesoporous silica. The structure directing role of SBA-15 had an obvious impact on the growth of MOF crystals, which in turn affected the morphologies and structural properties of the composites. The pristine HKUST-1 and the composites with different content of SBA-15 were characterized by XRD, N 2 adsorption-desorption, SEM, TEM, FT-IR, TG, XPS, and CO 2 -TPD techniques. It was found that the composites were assembled by oriented growth of MOF nanocrystals on the surfaces of SBA-15 matrix. The interactions between surface silanol groups and metal centers induced structural changes and resulted in the increases in surface areas as well as micropore volumes of hybrid materials. Besides, the additional constraints from SBA-15 also restrained the expansion of HKUST-1, contributing to their smaller crystal sizes in the composites. The adsorption isotherms of CO 2 on the materials were measured and applied to calculate the isosteric heats of adsorption. The HS-1 composite exhibited an increase of 15.9% in CO 2 uptake capacity compared with that of HKUST-1. Moreover, its higher isosteric heats of CO 2 adsorption indicated the stronger interactions between the surfaces and CO 2 molecules. The adsorption rate of the composite was also improved due to the introduction of mesopores. Ten cycles of CO 2 adsorption-desorption experiments implied that the HS-1 had excellent reversibility of CO 2 adsorption. This study was intended to provide the possibility of assembling new composites with tailored properties based on MOF and mesoporous silica to satisfy the requirements of various applications.

  18. Direct large-scale synthesis of 3D hierarchical mesoporous NiO microspheres as high-performance anode materials for lithium ion batteries.

    bai, Zhongchao; Ju, Zhicheng; Guo, Chunli; Qian, Yitai; Tang, Bin; Xiong, Shenglin

    2014-03-21

    Hierarchically porous materials are an ideal material platform for constructing high performance Li-ion batteries (LIBs), offering great advantages such as large contact area between the electrode and the electrolyte, fast and flexible transport pathways for the electrolyte ions and the space for buffering the strain caused by repeated Li insertion/extraction. In this work, NiO microspheres with hierarchically porous structures have been synthesized via a facile thermal decomposition method by only using a simple precursor. The superstructures are composed of nanocrystals with high specific surface area, large pore volume, and broad pore size distribution. The electrochemical properties of 3D hierarchical mesoporous NiO microspheres were examined by cyclic voltammetry and galvanostatic charge-discharge studies. The results demonstrate that the as-prepared NiO nanospheres are excellent electrode materials in LIBs with high specific capacity, good retention and rate performance. The 3D hierarchical mesoporous NiO microspheres can retain a reversible capacity of 800.2 mA h g(-1) after 100 cycles at a high current density of 500 mA g(-1).

  19. Co{sub 3}O{sub 4} nanoparticles embedded in ordered mesoporous carbon with enhanced performance as an anode material for Li-ion batteries

    Park, Junsu; Kim, Gil-Pyo [Seoul National University (SNU), World Class University (WCU) Program of Chemical Convergence for Energy and Environment C2E2, School of Chemical and Biological Engineering, College of Engineering, Institute of Chemical Processes (Korea, Republic of); Umh, Ha Nee [Kwangwoon University, Department of Chemical Engineering (Korea, Republic of); Nam, Inho; Park, Soomin [Seoul National University (SNU), World Class University (WCU) Program of Chemical Convergence for Energy and Environment C2E2, School of Chemical and Biological Engineering, College of Engineering, Institute of Chemical Processes (Korea, Republic of); Kim, Younghun [Kwangwoon University, Department of Chemical Engineering (Korea, Republic of); Yi, Jongheop, E-mail: jyi@snu.ac.kr [Seoul National University (SNU), World Class University (WCU) Program of Chemical Convergence for Energy and Environment C2E2, School of Chemical and Biological Engineering, College of Engineering, Institute of Chemical Processes (Korea, Republic of)

    2013-09-15

    A Co{sub 3}O{sub 4}/ordered mesoporous carbon (OMC) nanocomposite, in which Co{sub 3}O{sub 4} nanoparticles (NPs), with an average size of about 10 nm homogeneously embedded in the OMC framework, are prepared for use as an anode material in Li-ion batteries. The composite is prepared by a one-pot synthesis based on the solvent evaporation-induced co-self-assembly of a phenolic resol, a triblock copolymer F127, and Co(NO{sub 3}){sub 2}{center_dot}6H{sub 2}O, followed by carbonization and oxidation. The resulting material has a high reversible capacity of {approx}1,025 mA h g{sup -1} after 100 cycles at a current density of 0.1 A g{sup -1}. The enhanced cycling stability and rate capability of the composite can be attributed to the combined mesoporous nanostructure which provides efficient pathways for Li-ion transport and the homogeneous distribution of the Co{sub 3}O{sub 4} NPs in the pore wall of the OMC, which prevents aggregation. These findings suggest that the OMC has promise for use as a carbon metric for metals and metal oxides as an anode material in high performance Li-ion batteries.

  20. High electrochemical performance of RuO_2–Fe_2O_3 nanoparticles embedded ordered mesoporous carbon as a supercapacitor electrode material

    Xiang, Dong; Yin, Longwei; Wang, Chenxiang; Zhang, Luyuan

    2016-01-01

    The electrode materials RuO_2 or RuO_2–Fe_2O_3 nanoparticle embedded OMC (ordered mesoporous carbon) are prepared by the method of impregnation and heating in situ. The mesoporous structure optimized the electron and proton conducting pathways, leading to the enhanced capacitive performances of the composite materials. The average nanoparticle size of RuO_2 and RuO_2–Fe_2O_3 is 2.54 and 1.96 nm, respectively. The fine RuO_2–Fe_2O_3 nanoparticles are dispersed evenly in the pore channel wall of the two-dimensional mesoporous carbon without blocking the mesoporous channel, and they have a higher specific surface area, a larger pore volume, a proper pore size and a small charge transfer impedance value. The special electrochemical capacitance of RuO_2–Fe_2O_3/OMC tested in acid electrolyte (H_2SO_4) is measured to be as high as 1668 F g"−"1, which is higher than that of RuO_2/OMC. Meanwhile, the supercapacitor properties of the RuO_2–Fe_2O_3/OMC composites show a good cycling performance of 93% capacitance retention (3000 cycles), a better reversibility, a higher energy density (134 Wh kg"−"1) and power density (4000 W kg"−"1). The composite electrode of RuO_2–Fe_2O_3/OMC, which combines a double layer capacitance with pseudo-capacitance, is proved to be suitable for ideal high performance electrode material of a hybrid supercapacitor application. - Highlights: • The nanocomposites of RuO_2–Fe_2O_3/OMC are prepared by impregnation and heating in situ. • The fine RuO_2–Fe_2O_3 nanoparticles distribute in the pore channel wall of OMC. • We discuss a reversible redox reaction mechanism of RuO_2–Fe_2O_3/OMC in acid solutions. • RuO_2–Fe_2O_3 nanoparticles embedded OMC shows a higher supercapacitive performance.

  1. Dynamic mean field theory for lattice gas models of fluid mixtures confined in mesoporous materials.

    Edison, J R; Monson, P A

    2013-11-12

    We present the extension of dynamic mean field theory (DMFT) for fluids in porous materials (Monson, P. A. J. Chem. Phys. 2008, 128, 084701) to the case of mixtures. The theory can be used to describe the relaxation processes in the approach to equilibrium or metastable equilibrium states for fluids in pores after a change in the bulk pressure or composition. It is especially useful for studying systems where there are capillary condensation or evaporation transitions. Nucleation processes associated with these transitions are emergent features of the theory and can be visualized via the time dependence of the density distribution and composition distribution in the system. For mixtures an important component of the dynamics is relaxation of the composition distribution in the system, especially in the neighborhood of vapor-liquid interfaces. We consider two different types of mixtures, modeling hydrocarbon adsorption in carbon-like slit pores. We first present results on bulk phase equilibria of the mixtures and then the equilibrium (stable/metastable) behavior of these mixtures in a finite slit pore and an inkbottle pore. We then use DMFT to describe the evolution of the density and composition in the pore in the approach to equilibrium after changing the state of the bulk fluid via composition or pressure changes.

  2. Synthesis of non-siliceous mesoporous oxides.

    Gu, Dong; Schüth, Ferdi

    2014-01-07

    Mesoporous non-siliceous oxides have attracted great interest due to their unique properties and potential applications. Since the discovery of mesoporous silicates in 1990s, organic-inorganic assembly processes by using surfactants or block copolymers as soft templates have been considered as a feasible path for creating mesopores in metal oxides. However, the harsh sol-gel conditions and low thermal stabilities have limited the expansion of this method to various metal oxide species. Nanocasting, using ordered mesoporous silica or carbon as a hard template, has provided possibilities for preparing novel mesoporous materials with new structures, compositions and high thermal stabilities. This review concerns the synthesis, composition, and parameter control of mesoporous non-siliceous oxides. Four synthesis routes, i.e. soft-templating (surfactants or block copolymers as templates), hard-templating (mesoporous silicas or carbons as sacrificial templates), colloidal crystal templating (3-D ordered colloidal particles as a template), and super lattice routes, are summarized in this review. Mesoporous metal oxides with different compositions have different properties. Non-siliceous mesoporous oxides are comprehensively described, including a discussion of constituting elements, synthesis, and structures. General aspects concerning pore size control, atomic scale crystallinity, and phase control are also reviewed.

  3. Research Update: Mesoporous sensor nanoarchitectonics

    Katsuhiko Ariga

    2014-03-01

    Full Text Available In this short review, we have selected three main subjects: (i mesoporous materials, (ii sensing applications, and (iii the concept of nanoarchitectonics, as examples of recent hot topics in nanomaterials research. Mesoporous materials satisfy the conditions necessary not only for a wide range of applications but also for ease of production, by a variety of simple processes, which yield bulk quantities of materials without loss of their well-defined nanometric structural features. Sensing applications are of general importance because many events arise from interaction with external stimuli. In addition to these important features, nanoarchitectonics is a concept aimed at production of novel functionality of whole units according to concerted interactions within nanostructures. For the combined subject of mesoporous sensor nanoarchitectonics, we present recent examples of research in the corresponding fields categorized according to mechanism of detection including optical, electrical, and piezoelectric sensing.

  4. Highly stable and regenerable Mn-based/SBA-15 sorbents for desulfurization of hot coal gas

    Zhang, F.M.; Liu, B.S.; Zhang, Y.; Guo, Y.H.; Wan, Z.Y.; Subhan, Fazle

    2012-01-01

    Highlights: ► A series of mesoporous Cu x Mn y O z /SBA-15 sorbents were fabricated for hot coal gas desulfurization. ► 1Cu9Mn/SBA-15 sorbent with high breakthrough sulfur capacity is high stable and regenerable. ► Utilization of SBA-15 constrained the sintering and pulverization of sorbents. - Abstract: A series of mesoporous xCuyMn/SBA-15 sorbents with different Cu/Mn atomic ratios were prepared by wet impregnation method and their desulfurization performance in hot coal gas was investigated in a fixed-bed quartz reactor in the range of 700–850 °C. The successive nine desulfurization–regeneration cycles at 800 °C revealed that 1Cu9Mn/SBA-15 presented high performance with durable regeneration ability due to the high dispersion of Mn 2 O 3 particles incorporated with a certain amount of copper oxides. The breakthrough sulfur capacity of 1Cu9Mn/SBA-15 observed 800 °C is 13.8 g S/100 g sorbents, which is remarkably higher than these of 40 wt%LaFeO 3 /SBA-15 (4.8 g S/100 g sorbents) and 50 wt%LaFe 2 O x /MCM-41 (5.58 g S/100 g sorbents) used only at 500–550 °C. This suggested that the loading of Mn 2 O 3 active species with high thermal stability to SBA-15 support significantly increased sulfur capacity at relatively higher sulfidation temperature. The fresh and used xCuyMn/SBA-15 sorbents were characterized by means of BET, XRD, XPS, XAES, TG/DSC and HRTEM techniques, confirmed that the structure of the sorbents remained intact before and after hot coal gas desulfurization.

  5. Multiwalled carbon nanotubes as a sorbent material for the solid phase extraction of lead from urine and subsequent determination by electrothermal atomic absorption spectrometry

    Peña Crecente, Rosa M.; Lovera, Carlha Gutiérrez; García, Julia Barciela; Méndez, Jennifer Álvarez; Martín, Sagrario García; Latorre, Carlos Herrero, E-mail: carlos.herrero@usc.es

    2014-11-01

    The determination of lead in urine is a way of monitoring the chemical exposure to this metal. In the present paper, a new method for the Pb determination by electrothermal atomic absorption spectrometry (ETAAS) in urine at low levels has been developed. Lead was separated from the undesirable urine matrix by means of a solid phase extraction (SPE) procedure. Oxidized multiwalled carbon nanotubes have been used as a sorbent material. Lead from urine was retained at pH 4.0 and was quantitatively eluted using a 0.7 M nitric acid solution and was subsequently measured by ETAAS. The effects of parameters that influence the adsorption–elution process (such as pH, eluent volume and concentration, sampling and elution flow rates) and the atomic spectrometry conditions have been studied by means of different factorial design strategies. Under the optimized conditions, the detection and quantification limits obtained were 0.08 and 0.26 μg Pb L{sup −1}, respectively. The results demonstrate the absence of a urine matrix effect and this is the consequence of the SPE process carried out. Therefore, the developed method is useful for the analysis of Pb at low levels in real samples without the influence of other urine components. The proposed method was applied to the determination of lead in urine samples of unexposed healthy people and satisfactory results were obtained (in the range 3.64–22.9 μg Pb L{sup −1}). - Highlights: • Lead determination in urine using a solid phase extraction procedure followed by ETAAS • Carbon nanotubes as SPE adsorbent for Pb in urine • Matrix elimination for the Pb determination in urine by using SPE based on carbon nanotubes • The detection limit was 0.08 μg Pb L{sup −1}.

  6. Synthesis Mechanism and Thermal Optimization of an Economical Mesoporous Material Using Silica: Implications for the Effective Removal or Delivery of Ibuprofen.

    Shanmuga Kittappa

    Full Text Available Mesoporous silica materials (MSMs were synthesized economically using silica (SiO2 as a precursor via a modified alkaline fusion method. The MSM prepared at 500°C (MSM-500 had the highest surface area, pore size, and volume, and the results of isotherms and the kinetics of ibuprofen (IBP removal indicated that MSM-500 had the highest sorption capacity and fastest removal speed vs. SBA-15 and zeolite. Compared with commercial granular activated carbon (GAC, MSM-500 had a ~100 times higher sorption rate at neutral pH. IBP uptake by MSM-500 was thermodynamically favorable at room temperature, which was interpreted as indicating relatively weak bonding because the entropy (∆adsS, -0.07 J mol(-1 K(-1 was much smaller. Five times recycling tests revealed that MSM-500 had 83-87% recovery efficiencies and slower uptake speeds due to slight deformation of the outer pore structure. In the IBP delivery test, MSM-500 drug loading was 41%, higher than the reported value of SBA-15 (31%. The in vitro release of IBP was faster, almost 100%, reaching equilibrium within a few hours, indicating its effective loading and unloading characteristics. A cost analysis study revealed that the MSM was ~10-70 times cheaper than any other mesoporous silica material for the removal or delivery of IBP.

  7. Laboratory studies and model simulations of sorbent material behavior for an in-situ passive treatment barrier

    Aloysius, D.; Fuhrmann, M.

    1995-01-01

    This paper presents a study combining laboratory experiments and model simulations in support of the design and construction of a passive treatment barrier (or filter wall) for retarding the migration of Sr-90 within a water-bearing surficial sand and gravel layer. Preliminary evaluation was used to select materials for column testing. A one-dimensional finite-difference model was used to simulate the laboratory column results and extrapolation of the calibrated model was then used to assess barrier performance over extended time frames with respect to Sr-90 breakthrough and loading on the filter media. The final results of the study showed that 20 by 50 mesh clinoptilolite will attenuate Sr-90 with a maximum life expentancy of approximately 10 years. This time period is based on allowable limits of Sr-90 activity on the filter media and is also a function of site-specific conditions

  8. Ti2Nb10O29-x mesoporous microspheres as promising anode materials for high-performance lithium-ion batteries

    Deng, Shengjue; Luo, Zhibin; Liu, Yating; Lou, Xiaoming; Lin, Chunfu; Yang, Chao; Zhao, Hua; Zheng, Peng; Sun, Zhongliang; Li, Jianbao; Wang, Ning; Wu, Hui

    2017-09-01

    Ti2Nb10O29 has recently been reported as a promising anode material for lithium-ion batteries. However, its poor electronic conductivity and insufficient Li+-ion diffusion coefficient significantly limit its rate capability. To tackle this issue, a strategy combining nanosizing and crystal-structure modification is employed. Ti2Nb10O29-x mesoporous microspheres with a sphere-size range of 0.5-4 μm are prepared by a one-step solvothermal method followed by thermal treatment in N2. These Ti2Nb10O29-x mesoporous microspheres exhibit primary nanoparticles, a large specific surface area (22.9 m2 g-1) and suitable pore sizes, leading to easy electron/Li+-ion transport and good interfacial reactivity. Ti2Nb10O29-x shows a defective shear ReO3 crystal structure with O2- vacancies and an increased unit cell volume, resulting in its increased Li+-ion diffusion coefficient. Besides Ti4+ and Nb5+ ions, Ti2Nb10O29-x comprises Nb4+ ions with unpaired 4d electrons, which significantly increase its electronic conductivity. As a result of these improvements, the Ti2Nb10O29-x mesoporous microspheres reveal superior electrochemical performances in term of large reversible specific capacity (309 mAh g-1 at 0.1 C), outstanding rate capability (235 mAh g-1 at 40 C) and durable cyclic stability (capacity retention of 92.1% over 100 cycles at 10 C).

  9. Application of clay minerals from Cayo Guan, Cuba, as sorbents of heavy metals and ceramic raw materials

    Fonseca, D.; Barba, F.; Callejas, P.; Recio, P.

    2012-01-01

    It has been studied by Analysis Heating Microscope Optical the behaviour of some kaolinitic clays from a reservoir of Cayo Guan rich in iron oxides and low silica content proving to be a refractory materials whose softening appears after 1500 degree centigrade. It has obtained the workability diagram of the different clay minerals calculating the plasticity by the method of Casagrande spoon; only one of the samples is in the area suitable for extrusion. Vitrification diagrams report that the capacity of water absorption is 2 +, Cr 3 +. The results of the immobilization of these elements have been compared with those obtained with thermally activated vermiculite at 800 degree centigrade, showing that the treated samples show sorption of both cadmium and chromium below the vermiculite, but the non-treated ones are suitable to remove chromium; this is because these clays do not contain in its composition exchangeable ions (Ca 2 +, Mg 2 +, Na + , K + ), and even if they are chemically activated only the presence of Fe ions is which produces form bindings (Cr x .Fe 1 -x) (OH) 3 which favor Cr sorption. (Author) 26 refs.

  10. A novel approach to mitigating sulphur dioxide emissions and producing a mercury sorbent material using oil-sands fluid coke

    Morris, E.; Jia, C.Q.; Tong, S.

    2008-01-01

    Pyrometallurgical smelting operations are a major source of sulphur dioxide (SO 2 ) which is a precursor to acid rain and increased levels of UV-B penetration in boreal lakes. Mercury is also released in copper smelter off-gas, which can bioaccumulate and cause neurological disorders and death in humans. Fluid coke is produced in massive quantities as a by-product of bitumen upgrading at Syncrude Canada's facility in Fort McMurray, Alberta. Oilsands fluid coke can be used to reduce SO 2 and produce elemental sulphur as a co-product. This process was dubbed SOactive. The reaction physically activates the fluid coke to produce a sulphur-impregnated activated carbon (SIAC) which is known as ECOcarbon. Some studies have indicated that SIAC is well suited for the removal of vapour phase mercury, mainly due to the formation of stable mercuric sulphide species. This paper discussed the findings made to date in relation to the SOactive process and the characterization of ECOcarbons. The paper discussed the use of fluid coke for reducing SO 2 emissions while producing elemental sulphur as well as coke-SO 2 -oxygen (O 2 ) and coke-SO 2 -water (H 2 O) systems. The paper also examined the production of SIAC products for use in capturing vapour phase mercury. The paper presented the materials and methodology, including an illustration of the apparatus used in reduction of SO 2 and activation of fluid coke. It was concluded that more work is still needed to analyse the effect of O 2 and SO 2 reduction and SIAC properties under smelter flue gas conditions. 10 refs., 1 tab., 8 figs

  11. Sorption studies of radionuclides on a modified mesoporous cerium(IV) silicate

    Sepehrian, H.; Tarbiat Moallem University, Tehran; Ghannadi-Maragheh, M.; Yavari, R.; Khanchi, A.R.; Waqif-Husain, S.

    2008-01-01

    Five different samples of a new sorbent, modified mesoporous cerium(IV) silicate have been prepared with various mole ratios of Si/Ce and Cetyltrimethylammonium bromide (CTMABr) as template. XRD, nitrogen sorption, SEM, IR, thermogravimetry and sorption of radionuclides have been studied. Separation of Hg(II)-Th(IV), Hg(II)-Zr(IV) and Rb(I)-Zr(IV) have been developed on columns of this novel sorbent. (author)

  12. Space-filling polyhedral sorbents

    Haaland, Peter

    2016-06-21

    Solid sorbents, systems, and methods for pumping, storage, and purification of gases are disclosed. They derive from the dynamics of porous and free convection for specific gas/sorbent combinations and use space filling polyhedral microliths with facial aplanarities to produce sorbent arrays with interpenetrating interstitial manifolds of voids.

  13. Analysis of Ethane and Diethylbenzene Bridged Sorbents

    2017-12-13

    Textiles modified in this manner have been shown to reduce or eliminate transport of chemical warfare agents and simulants across the fabric barrier...B.J. Johnson; B.J. Melde; M.H. Moore; A.P. Malanoski; J.R. Taft, "Improving sorbents for glycerol capture in biodiesel refinement," Materials 10

  14. Enhanced thermal properties of novel shape-stabilized PEG composite phase change materials with radial mesoporous silica sphere for thermal energy storage.

    Min, Xin; Fang, Minghao; Huang, Zhaohui; Liu, Yan'gai; Huang, Yaoting; Wen, Ruilong; Qian, Tingting; Wu, Xiaowen

    2015-08-11

    Radial mesoporous silica (RMS) sphere was tailor-made for further applications in producing shape-stabilized composite phase change materials (ss-CPCMs) through a facile self-assembly process using CTAB as the main template and TEOS as SiO2 precursor. Novel ss-CPCMs composed of polyethylene glycol (PEG) and RMS were prepared through vacuum impregnating method. Various techniques were employed to characterize the structural and thermal properties of the ss-CPCMs. The DSC results indicated that the PEG/RMS ss-CPCM was a promising candidate for building thermal energy storage applications due to its large latent heat, suitable phase change temperature, good thermal reliability, as well as the excellent chemical compatibility and thermal stability. Importantly, the possible formation mechanisms of both RMS sphere and PEG/RMS composite have also been proposed. The results also indicated that the properties of the PEG/RMS ss-CPCMs are influenced by the adsorption limitation of the PEG molecule from RMS sphere with mesoporous structure and the effect of RMS, as the impurities, on the perfect crystallization of PEG.

  15. Carbon dioxide adsorption on micro-mesoporous composite materials of ZSM-12/MCM-48 type: The role of the contents of zeolite and functionalized amine

    2CEM, São Cristovão/SE (Brazil))" data-affiliation=" (Federal University of Sergipe, Materials Science and Engineering Postgraduate Program P2CEM, São Cristovão/SE (Brazil))" >Santos, S.C.G.; Pedrosa, A.M.Garrido; Souza, M.J.B.; Cecilia, J.A.; Rodríguez-Castellón, E.

    2015-01-01

    Highlights: • Synthesis of the micro-mesoporous composite materials of ZSM-12/MCM-48 type. • Application of these adsorbents in the carbon dioxide adsorption. • Effects of the contents of zeolite and amino group in the material surface on the CO 2 capture efficiency. - Abstract: In this study ZSM-12/MCM-48 adsorbents have been synthesized at three ZSM-12 content, and also were functionalizated with amine groups by grafting. All the adsorbents synthesized were evaluated for CO 2 capture. The X-ray diffraction analysis of the ZSM-12/MCM-48 composite showed the main characteristic peaks of ZSM-12 and MCM-48, and after the functionalization, the structure of MCM-48 on the composite impregnated was affected due amine presence. For the composites without amine, the ZSM-12 content was the factor determining in the adsorption capacity of CO 2 and for the composites with amine the amount of amine was that influenced in the adsorption capacity

  16. Efficient luminescent materials based on the incorporation of a Eu(III)tris-(bipyridine-carboxylate) complex in mesoporous hybrid silicate hosts

    Botelho, M.B.S. [Instituto de Física de São Carlos, Universidade de São Paulo, 13566-590 São Carlos, SP (Brazil); Universidade de Brasilia, 70910-900 Brasilia, DF (Brazil); Queiroz, T.B. de [Instituto de Física de São Carlos, Universidade de São Paulo, 13566-590 São Carlos, SP (Brazil); Eckert, H. [Instituto de Física de São Carlos, Universidade de São Paulo, 13566-590 São Carlos, SP (Brazil); Institut für Physikalische Chemie, Westfälische Wilhelms Universität Münster, D-48149 Münster (Germany); Camargo, A.S.S. de, E-mail: andreasc@ifsc.usp.br [Instituto de Física de São Carlos, Universidade de São Paulo, 13566-590 São Carlos, SP (Brazil)

    2016-02-15

    The study of the photoluminescent characteristics of host–guest systems based on highly emissive trivalent rare earth complexes such as Eu{sup 3+} – tris-bipyridine-carboxylate, immobilized in solid state host matrices, is motivated by their potential applications in optoelectronic devices and bioanalytical systems. Besides offering the possibility of designing a favorable environment to improve the photophysical properties of the guest molecules, encapsulation in porous solids also serves to protect such molecules, prevents leakage (especially critical for bio-applications) and ultimately leads to more robust and versatile materials. Among the most interesting possible host matrices are mesoporous silica and hybrids (organo-silicates) in the form of powders (MCM-41 like) and transparent bulk or film xerogels. In this work we report the synthesis of highly efficient red emitting materials based on the wet impregnation of such host matrices with the new complex Eu[4-(4′-tert-butyl-biphenyl-4-yl)-2,2′-bipyridine-6-carboxyl]{sub 3} (“[{sup t}Bu–COO]{sub 3}Eu”) whose synthesis and photophysical characterization was recently reported. Prior to the incorporation, the host matrices were thoroughly characterized by solid state {sup 29}Si and {sup 1}H NMR, N{sub 2} adsorption/desorption isotherms, and scanning electron microscopy (SEM). Incorporation and retention of the complex molecules are found to be significantly higher in the phenyl-modified hybrid samples than in the regular mesoporous silica, suggesting efficient immobilization of the complex by π–π interactions. Long excited state lifetimes (up to 1.7 ms comparable to 1.8 ms for the complex in solution), and high quantum yields (up to 65%, versus 85% for the complex in solution) were measured for the bulk xerogel materials, suggesting the potential use of thin films for lighting and bioanalytical applications. - Highlights: • New Eu(III) complex in mesoporous hybrid matrices leads to highly

  17. Efficient luminescent materials based on the incorporation of a Eu(III)tris-(bipyridine-carboxylate) complex in mesoporous hybrid silicate hosts

    Botelho, M.B.S.; Queiroz, T.B. de; Eckert, H.; Camargo, A.S.S. de

    2016-01-01

    The study of the photoluminescent characteristics of host–guest systems based on highly emissive trivalent rare earth complexes such as Eu 3+ – tris-bipyridine-carboxylate, immobilized in solid state host matrices, is motivated by their potential applications in optoelectronic devices and bioanalytical systems. Besides offering the possibility of designing a favorable environment to improve the photophysical properties of the guest molecules, encapsulation in porous solids also serves to protect such molecules, prevents leakage (especially critical for bio-applications) and ultimately leads to more robust and versatile materials. Among the most interesting possible host matrices are mesoporous silica and hybrids (organo-silicates) in the form of powders (MCM-41 like) and transparent bulk or film xerogels. In this work we report the synthesis of highly efficient red emitting materials based on the wet impregnation of such host matrices with the new complex Eu[4-(4′-tert-butyl-biphenyl-4-yl)-2,2′-bipyridine-6-carboxyl] 3 (“[ t Bu–COO] 3 Eu”) whose synthesis and photophysical characterization was recently reported. Prior to the incorporation, the host matrices were thoroughly characterized by solid state 29 Si and 1 H NMR, N 2 adsorption/desorption isotherms, and scanning electron microscopy (SEM). Incorporation and retention of the complex molecules are found to be significantly higher in the phenyl-modified hybrid samples than in the regular mesoporous silica, suggesting efficient immobilization of the complex by π–π interactions. Long excited state lifetimes (up to 1.7 ms comparable to 1.8 ms for the complex in solution), and high quantum yields (up to 65%, versus 85% for the complex in solution) were measured for the bulk xerogel materials, suggesting the potential use of thin films for lighting and bioanalytical applications. - Highlights: • New Eu(III) complex in mesoporous hybrid matrices leads to highly emissive material • Matrix

  18. PROCEEDINGS: MULTIPOLLUTANT SORBENT REACTIVITY ...

    The report is a compilation of technical papers and visual aids presented by representatives of industry, academia, and government agencies at a workshop on multipollutant sorbent reactivity that was held at EPA's Environmental Research Center in Research Triangle Park, NC, on July 19-20, 1994. There were 16 technical presentations in three sessions, and a panel discussion between six research experts. The workshop was a forum for the exchange of ideas and information on the use of sorbents to control air emissions of acid gases (sulfur dioxide, nitrogen oxides, and hydrogen chloride); mercury and dioxins; and toxic metals, primarily from fossil fuel combustion. A secondary purpose for conducting the workshop was to help guide EPA's research planning activities. A general theme of the workshop was that a strategy of controlling many pollutants with a single system rather than systems to control individual pollutants should be a research goal. Some research needs cited were: hazardous air pollutant removal by flue gas desulfurization systems, dioxin formation and control, mercury control, waste minimization, impact of ash recycling on metals partitioning, impact of urea and sorbents on other pollutants, high temperature filtration, impact of coal cleaning on metals partitioning, and modeling dispersion of sorbents in flue gas. information

  19. Sorbent-based Oxygen Production for Energy Systems

    Sethi, Vijay [Western Research Inst. (WRI), Laramie, WY (United States)

    2017-01-31

    Project DE-FE0024075 deals with the development of a moderate-temperature sorbent-based oxygen production technology. Sorbent-based oxygen production process utilizes oxygen-storage properties of Perovskites to (1) adsorb oxygen from air in a solid sorbent, and (2) release the adsorbed oxygen into a sweep gas such as CO2 and/or steam for gasification systems or recycled flue gas for oxy-combustion systems. Pure oxygen can be produced by the use of vacuum instead of a sweep gas to affect the pressure swing. By developing more efficient and stable, higher sorption capacity, newer class of materials operating at moderate temperatures this process represents a major advancement in air separation technology. Newly developed perovskite ceramic sorbent materials with order-disorder transition have a higher O2 adsorption capacity, potentially 200 °C lower operating temperatures, and up to two orders of magnitude faster desorption rates than those used in earlier development efforts. The performance advancements afforded by the new materials lead to substantial savings in capital investment and operational costs. Cost of producing oxygen using sorbents could be as much as 26% lower than VPSA and about 13% lower than a large cryogenic air separation unit. Cost advantage against large cryogenic separation is limited because sorbent-based separation numbers up sorbent modules for achieving the larger capacity.

  20. Moderate Temperature Synthesis of Mesoporous Carbon

    Dua, Rubal; Wang, Peng

    2013-01-01

    Methods and composition for preparation of mesoporous carbon material are provided. For example, in certain aspects methods for carbonization and activation at selected temperature ranges are described. Furthermore, the invention provides products prepared therefrom.

  1. Moderate Temperature Synthesis of Mesoporous Carbon

    Dua, Rubal

    2013-01-03

    Methods and composition for preparation of mesoporous carbon material are provided. For example, in certain aspects methods for carbonization and activation at selected temperature ranges are described. Furthermore, the invention provides products prepared therefrom.

  2. Enhanced electrochemical performance of mesoporous NiCo{sub 2}O{sub 4} as an excellent supercapacitive alternative energy storage material

    Bhojane, Prateek [Center for Materials Science and Engineering, Indian Institute of Technology Indore, Simrol Campus, Khandwa Road, Indore 452020 (India); Sen, Somaditya [Center for Materials Science and Engineering, Indian Institute of Technology Indore, Simrol Campus, Khandwa Road, Indore 452020 (India); Department of Physics, Indian Institute of Technology Indore, Simrol Campus, Khandwa Road, Indore 452020 (India); Shirage, Parasharam M., E-mail: paras.shirage@gmail.com [Center for Materials Science and Engineering, Indian Institute of Technology Indore, Simrol Campus, Khandwa Road, Indore 452020 (India); Department of Physics, Indian Institute of Technology Indore, Simrol Campus, Khandwa Road, Indore 452020 (India)

    2016-07-30

    Highlights: • A facile technique to grow mesopores NiCo{sub 2}O{sub 4} flakes. • High specific capacitance. • High capacitance retention at higher cycles. • A promising candidate for energy storage device. - Abstract: Here we report the supercapacitive properties of mesoporous nickel cobalt oxide (NiCo{sub 2}O{sub 4}) synthesized by fast, inexpensive and facile chemical bath method, by avoiding high pressure, high temperature and chemical complexity. Physico-chemical characterization techniques such as X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Raman Spectra, and nitrogen adsorption–desorption isotherm analysis is performed to characterize the electrode material. Brunauer-Emmett-Teller (BET) measurements reveal the surface area 52.86 m{sup 2} g{sup −1} and from Barrett-Joyner-Halenda (BJH), typical pores size ranges between 10 and 50 nm, also confirms the mesoporosity. The electrochemical properties are measured by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charging/discharging. The synthesized material exhibits remarkably enhanced electrochemical performance with specific capacitance of 1130 F g{sup −1} at 1 mV s{sup −1} sweep rate and 1125 F g{sup −1} at current density of 0.05 A g{sup −1}, highest without supporting base like carbon cloth, Ni-foam, Ti- foil used for direct growth (deposition) of electrode material. It is superior to those of its individual and hybrid components prepared by similar technique. Ragone plot shows high specific energy density (49.25 Wh kg{sup −1}) and corresponding specific power density (1851.31 W kg{sup −1}) even at high current density of 0.5 A g{sup −1}.

  3. Microwave synthesis of nanostructured oxide sorbents doped with lanthanides

    Mitrofanov, Andrey A., E-mail: mitrofanov-a@icloud.com; Silyavka, Elena S.; Shilovskikh, Vladimir V.; Kolonitckii, Petr D.; Sukhodolov, Nikolai G.; Selyutin, Artem A., E-mail: selutin@inbox.ru [Saint Petersburg State University, 7/9, Universitetskaya nab., St. Petersburg, 199034 (Russian Federation)

    2016-06-17

    A number of nanostructured mesoporous oxide systems based on aluminum oxide, doped with lanthanide ions have been obtained in this study. Structure and morphology of oxides obtained have been examined by X-ray diffraction analysis, thermogravimetric analysis, scanning electron microscopy. The surface area of the samples was determined by the BET method. The dependence of the adsorption of insulin on synthesized oxides from the concentration was investigated. The containing of insulin in solutions after adsorption was determined by the Bradford method. The isotherms of adsorption of insulin on resulting oxide sorbents were plotted, the dependence capacity of the sorption of insulin from the lanthanide dopant was determined.

  4. The antimicrobial efficiency of silver activated sorbents

    Đolić, Maja B.; Rajaković-Ognjanović, Vladana N.; Štrbac, Svetlana B.; Rakočević, Zlatko Lj.; Veljović, Đorđe N.; Dimitrijević, Suzana I.; Rajaković, Ljubinka V.

    2015-01-01

    Highlights: • Different sorbents were activated by Ag + -ions and modified sorbents were determined by sorption capacities, in range of values: 42.06–3.28 mg/g. • Granulated activated carbon (GAC), natural zeolit (Z) and titanium dioxide (T) activated by Ag + -ions were tested against E. coli, S. aureus and C. albicans. • The most successful bacteria removal was obtained using Ag/Z against S. aureus and E. coli, while the yeast cell reduction reached unsatisfactory effect for all three activated sorbents. • XRD, XPS and FE-SEM analysis showed that the chemical state of the silver activating agent affects the antimicrobial activity, as well as the structural properties of the material. • An overall microbial cell reduction, which is performed by separated antimicrobial tests on the Ag + -activated surface and Ag + -ions in aquatic solutions, is a consequence of both mechanisms. - Abstract: This study is focused on the surface modifications of the materials that are used for antimicrobial water treatment. Sorbents of different origin were activated by Ag + -ions. The selection of the most appropriate materials and the most effective activation agents was done according to the results of the sorption and desorption kinetic studies. Sorption capacities of selected sorbents: granulated activated carbon (GAC), zeolite (Z), and titanium dioxide (T), activated by Ag + -ions were following: 42.06, 13.51 and 17.53 mg/g, respectively. The antimicrobial activity of Ag/Z, Ag/GAC and Ag/T sorbents were tested against Gram-negative bacteria E. coli, Gram-positive bacteria S. aureus and yeast C. albicans. After 15 min of exposure period, the highest cell removal was obtained using Ag/Z against S. aureus and E. coli, 98.8 and 93.5%, respectively. Yeast cell inactivation was unsatisfactory for all three activated sorbents. The antimicrobial pathway of the activated sorbents has been examined by two separate tests – Ag + -ions desorbed from the activated surface to the

  5. High performance of mesoporous γ-Fe2O3 nanoparticle/Ketjen Black composite as anode material for lithium ion batteries

    Dong, Hui; Xu, Yunlong; Ji, Mandi; Zhang, Huang; Zhao, Zhen; Zhao, Chongjun

    2015-01-01

    Highlights: • A mesoporous γ-Fe 2 O 3 /KB composite was synthesized via solvothermal method. • KB was used as a carbon template to improve electrochemical performance of γ-Fe 2 O 3 . • 3D network structure can relieve volume change and improve the ionic transport. • The composite exhibited an ultrahigh capacity and high rate performance. - Abstract: A type of γ-Fe 2 O 3 nanoparticle/Ketjen Black (KB) composite material is synthesized by a solvothermal method combined with precursor thermal transformation. The structure and morphology are characterized by XRD, raman spectra, TG, nitrogen sorption, SEM, TEM and EDS. The results show that the composite has a uniform nanoporous network and well-dispersed γ-Fe 2 O 3 particles with a size of ca. 5 nm are embedded in the mesopores of KB. The γ-Fe 2 O 3 /KB exhibits superior eletrochemical performances to the bare γ-Fe 2 O 3 , especially at high current rate. The discharge capacity of the composite is 1100 mAh·g −1 at the first cycle and remains 988.8 mAh·g −1 after 100 cycles at 0.2 C. Moreover, it also maintains a high discharge capacity of 697.8 mAh·g −1 at 2 C and 410.1 mAh·g −1 at 5 C after 100 cycles, respectively. Such improved electrochemical performances could be attributed to the superior conductivity and favorable structure of KB, which contributes to the improvement in electronic conductivity and structure stability of γ-Fe 2 O 3 during the lithium ion insertion/desertion process

  6. Engineered sorbent barriers for low-level waste disposal

    Mitchell, S.J.; Freeman, H.D.; Buelt, J.L.

    1987-01-01

    The Engineered Sorbent Barriers Program at Pacific Northwest Laboratory is developing sorbent materials to prevent the migration of radionuclides from low-level waste sites. These materials would allow water to pass, preventing the bathtub effect at humid sites. Screening studies identified promising sorbent materials for three key radionuclides: for cesium, greensand; for cobalt, activated charcoal; and for strontium, synthetic zeolite of clinoptilolite. Mixtures of these sorbent materials were tested in 0.6-m-diameter columns using radioactive leachates. To simulate expected worst-case conditions, the leachate solution contained the radionuclides, competing cations, and a chelating agent, adjusted to a pH of 5. A sorbent barrier comprised of greensand (1 wt%), activated charcoal (6 wt%), synthetic zeolite (20 wt%), and soil (73 wt%) achieved the decontamination factors necessary to meet the regulatory performance requirements established for this study. Sorbent barriers can be applied to shallow land burial, as backfill around the waste or engineered structures, or as backup to other liner systems. 2 references, 6 figures, 3 tables

  7. Engineered sorbent barriers for low-level waste disposal.

    Freeman, H.D.; Mitchell, S.J.; Buelt, J.L.

    1986-12-01

    The Engineered Sorbent Barriers Program at Pacific Northwest Laboratory is investigating sorbent materials to prevent the migration of soluble radio nuclides from low-level waste sites. These materials would allow water to pass, preventing the bathtub effect at humid sites. Laboratory studies identifield promising sorbent materials for three key radionuclides: for cesium, greensand; for cobalt, activated charcoal; and for strontium, synthetic zeolite or clinoptilolite. Mixtures of these sorbent materials were tested in 0.6-m-diameter columns using radioactive leachates. To simulate expected worst-case conditions, the leachate solution contained the radionuclides, competing cations, and a chelating agent and was adjusted to a pH of 5. A sorbent barrier comprised of greensand (1 wt%), activated charcoal (6 wt%), synthetic zeolite (20 wt%), and local soil (73 wt%) achieved the decontamination factors necessary to meet the regulatory performance requirements established for this study. Sorbent barriers can be applied to shallow-land burial, as backfill around the waste or engineered structures, or as backup to other liner systems. 7 refs., 14 figs., 12 tabs.

  8. Engineered sorbent barriers for low-level waste disposal

    Freeman, H.D.; Mitchell, S.J.; Buelt, J.L.

    1986-12-01

    The Engineered Sorbent Barriers Program at Pacific Northwest Laboratory is investigating sorbent materials to prevent the migration of soluble radio nuclides from low-level waste sites. These materials would allow water to pass, preventing the bathtub effect at humid sites. Laboratory studies identifield promising sorbent materials for three key radionuclides: for cesium, greensand; for cobalt, activated charcoal; and for strontium, synthetic zeolite or clinoptilolite. Mixtures of these sorbent materials were tested in 0.6-m-diameter columns using radioactive leachates. To simulate expected worst-case conditions, the leachate solution contained the radionuclides, competing cations, and a chelating agent and was adjusted to a pH of 5. A sorbent barrier comprised of greensand (1 wt%), activated charcoal (6 wt%), synthetic zeolite (20 wt%), and local soil (73 wt%) achieved the decontamination factors necessary to meet the regulatory performance requirements established for this study. Sorbent barriers can be applied to shallow-land burial, as backfill around the waste or engineered structures, or as backup to other liner systems. 7 refs., 14 figs., 12 tabs

  9. Novel strategy for the preparation of graphene-encapsulated mesoporous metal oxides with enhanced lithium storage

    Lin, Rong; Yue, Wenbo; Niu, Fangzhou; Ma, Jie

    2016-01-01

    As potential anode materials for lithium-ion batteries, mesoporous metal oxides show high reversible capacities but relatively poor cycle stability due to the structural collapse during cycles. Graphene-encapsulated mesoporous metal oxides may increase the electronic conductivity of the composite as well as stabilize the mesostructure of metal oxides, thereby enhancing the electrochemical performance of mesoporous metal oxides. Herein we describe a novel strategy for the preparation of graphene-encapsulated mesoporous metal oxides (SnO_2, Mn_3O_4), which exhibit superior electrochemical performance compared to pure mesoporous metal oxides. Moreover, some mesoporous metal oxides may be further reduced to low-valence metal oxides when calcined in presence of graphene. Mesoporous metal oxides with high isoelectric points are not essential for this synthesis method since metal oxides are connected with graphene through mesoporous silica template, thus expanding the types of graphene-encapsulated mesoporous metal oxides.

  10. Mesoporous Transition Metal Oxides for Supercapacitors

    Wang, Yan; Guo, Jin; Wang, Tingfeng; Shao, Junfeng; Wang, Dong; Yang, Ying-Wei

    2015-01-01

    Recently, transition metal oxides, such as ruthenium oxide (RuO2), manganese dioxide (MnO2), nickel oxides (NiO) and cobalt oxide (Co3O4), have been widely investigated as electrode materials for pseudo-capacitors. In particular, these metal oxides with mesoporous structures have become very hot nanomaterials in the field of supercapacitors owing to their large specific surface areas and suitable pore size distributions. The high specific capacities of these mesoporous metal oxides are result...

  11. Mesoporous Carbon Produced from Tri-constituent Mesoporous Carbon-silica Composite for Water Purification

    Yu, Yanjie

    2012-01-01

    Highly ordered mesoporous carbon-silica nanocomposites with interpenetrating carbon and silica networks were synthesized by the evaporation-induced tri-constituent co- assembly approach. The removal of silica by concentrated NaOH solution produced mesoporous carbons, which contained not only the primary large pores, but also the secondary mesopores in the carbon walls. The thus synthesized mesoporous carbon was further activated by using ZnCl2. The activated mesoporous carbon showed an improved surface area and pore volume. The synthesized mesoporous carbon was tested for diuron removal from water and the results showed that the carbon gave a fast diuron adsorption kinetics and a high diuron removal capacity, which was attributable to the primary mesopore channels being the highway for mass transfer, which led to short diffusion path length and easy accessibility of the interpenetrated secondary mesopores. The optimal adsorption capacity of the porous carbon was determined to be 390 mg/g, the highest values ever reported for diuron adsorption on carbon-based materials.

  12. Mesoporous Carbon Produced from Tri-constituent Mesoporous Carbon-silica Composite for Water Purification

    Yu, Yanjie

    2012-05-01

    Highly ordered mesoporous carbon-silica nanocomposites with interpenetrating carbon and silica networks were synthesized by the evaporation-induced tri-constituent co- assembly approach. The removal of silica by concentrated NaOH solution produced mesoporous carbons, which contained not only the primary large pores, but also the secondary mesopores in the carbon walls. The thus synthesized mesoporous carbon was further activated by using ZnCl2. The activated mesoporous carbon showed an improved surface area and pore volume. The synthesized mesoporous carbon was tested for diuron removal from water and the results showed that the carbon gave a fast diuron adsorption kinetics and a high diuron removal capacity, which was attributable to the primary mesopore channels being the highway for mass transfer, which led to short diffusion path length and easy accessibility of the interpenetrated secondary mesopores. The optimal adsorption capacity of the porous carbon was determined to be 390 mg/g, the highest values ever reported for diuron adsorption on carbon-based materials.

  13. Sorbents for mercury removal from flue gas

    Granite, Evan J.; Hargis, Richard A.; Pennline, Henry W.

    1998-01-01

    A review of the various promoters and sorbents examined for the removal of mercury from flue gas is presented. Commercial sorbent processes are described along with the chemistry of the various sorbent-mercury interactions. Novel sorbents for removing mercury from flue gas are suggested. Since activated carbons are expensive, alternate sorbents and/or improved activated carbons are needed. Because of their lower cost, sorbent development work can focus on base metal oxides and halides. Additionally, the long-term sequestration of the mercury on the sorbent needs to be addressed. Contacting methods between the flue gas and the sorbent also merit investigation.

  14. New polymer bounces into sorbent market

    Roy, K.A.

    1991-01-01

    Spectacular spills like the Exxon Valdez capture headlines and dominate conversation, but most releases involve quantities too small to attract media attention. For these spills, companies often rely on sorbents to collect the oil and dispose it. These devices come in a variety of shapes, sizes and absorbent materials, including a new generation of products that offers solid results-literally. This paper reports on the Solidifier which absorbs oil, as well as chlorinated solvents, hydrocarbons and PCBs, and, as the name implies, solidifies into a rubber-like material. A polymer used extensively in the rubber industry is the key to the sorbent's success. Oil and other contaminants, act like catalysts. They dissolve into the polymer, causing its molecules to bond together and form a rubber-like mass. No. 2 diesel fuel oil can be bounced on the floor after it solidifies

  15. Synthesis and electrochemical characterization of mesoporous Li2FeSiO4/C composite cathode material for Li-ion batteries

    Kumar, Ajay; Jayakumar, O. D.; Bazzi, Khadije; Nazri, Gholam-Abbas; Naik, Vaman M.; Naik, Ratna

    2015-03-01

    Lithium iron silicate (Li2FeSiO4) has the potential as cathode for Li ion batteries due to its high theoretical capacity (~ 330 mAh/g) and improved safety. The application of Li2FeSiO4 as cathode material has been challenged by its poor electronic conductivity and slow lithium ion diffusion in the solid phase. In order to solve these problems, we have synthesized mesoporous Li2FeSiO4/C composites by sol-gel method using the tri-block copolymer (P123) as carbon source. The phase purity and morphology of the composite materials were characterized by x-ray diffraction, SEM and TEM. The XRD pattern confirmed the formation of ~ 12 nm size Li2FeSiO4 crystallites in composites annealed at 600 °C for 6 h under argon atmosphere. The electrochemical properties are measured using the composite material as positive electrode in a standard coin cell configuration with lithium as the active anode and the cells were tested using AC impedance spectroscopy, cyclic voltammetry, and galvanostatic charge/discharge cycling. The Li2FeSiO4/C composites showed a discharge capacity of ~ 240 mAh/g at a rate of C/30 at room temperature. The effect of different annealing temperature and synthesis time on the electrochemical performance of Li2FeSiO4/C will be presented.

  16. Solid-Phase Extraction of Hemoglobin from Human Whole Blood with a Coordination-Polymer-Derived Composite Material Based on ZnO and Mesoporous Carbon.

    Jia, Yuan; Xu, Xinxin; Ou, Jinzhao; Liu, Xiaoxia

    2017-11-13

    A composite material, ZnO@MC, has been synthesized successfully by calcination using a one-dimensional zinc-based coordination polymer as the precursor. In ZnO@MC, ZnO particles with a size of about 5-8 nm are dispersed evenly in a mesoporous carbon matrix. Adsorption experiments at pH 6.8 with 2 mg ZnO@MC as adsorbent illustrated an adsorption efficiency of 92.3 % in 5 mL hemoglobin (Hb) solution with a concentration of 100 mg L -1 . In contrast, the adsorption of bovine serum albumin can almost be ignored under the same conditions. The selectivity originates from a strong Zn II -histidine interaction between ZnO@MC and hemoglobin. The adsorption behavior of hemoglobin on ZnO@MC fits the Temkin model perfectly with a capacity as high as 11646 mg g -1 . The hemoglobin adsorbed on the composite material can be eluted easily with sodium dodecyl sulfate stripping reagent with an extraction efficiency of 87.7 %. Circular dichroism spectra and protein activity studies suggest the structure and biological activity of hemoglobin is the same before and after the adsorption/desorption experiment. Finally, the ZnO@MC composite material was employed to extract hemoglobin from human whole blood without any pretreatment, and gave a very satisfactory result. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Phosphoryl functionalized mesoporous silica for uranium adsorption

    Xue, Guo; Yurun, Feng; Li, Ma; Dezhi, Gao; Jie, Jing; Jincheng, Yu; Haibin, Sun; Hongyu, Gong; Yujun, Zhang

    2017-01-01

    Highlights: • Phosphoryl functionalized mesoporous silica (TBP-SBA-15) is synthesized. • The amino and phosphoryl groups are successfully grafted on SBA-15. • TBP-SBA-15 has high and rapid uranium adsorption capacity in broad pH range. • The U(VI) adsorption of TBP-SBA-15 is spontaneous and belongs to chemical adsorption. - Abstract: Phosphoryl functionalized mesoporous silica (TBP-SBA-15) was synthesized by modified mesoporous silica with γ-amino propyl triethoxy silane and tributyl phosphate. The obtained samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), small angle X-ray diffraction (SAXRD), thermo-gravimetric/differential thermalanalyzer (TG/DTA), N_2 adsorption–desorption (BET) and Fourier transform infrared spectroscopy (FT-IR) techniques. Results showed that TBP-SBA-15 had large surface areas with ordered channel structure. Moreover, the effects of adsorption time, sorbent dose, solution pH, initial uranium concentration and temperature on the uranium adsorption behaviors were investigated. TBP-SBA-15 showed a high uranium adsorption capacity in a broad range of pH values. The U(VI) adsorption rate of TBP-SBA-15 was fast and nearly achieved completion in 10 min with the sorbent dose of 1 g/L. The U(VI) adsorption of TBP-SBA-15 followed the pseudo-second-order kinetic model and Freundlich isotherm model, indicating that the process was belonged to chemical adsorption. Furthermore, the thermodynamic parameters (ΔG"0, ΔH"0 and ΔS"0) confirmed that the adsorption process was endothermic and spontaneous.

  18. Phosphoryl functionalized mesoporous silica for uranium adsorption

    Xue, Guo; Yurun, Feng; Li, Ma; Dezhi, Gao; Jie, Jing; Jincheng, Yu; Haibin, Sun [Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials of Ministry of Education, Shandong University, Jinan 250061 (China); Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Hongyu, Gong, E-mail: gong_hongyu@163.com [Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials of Ministry of Education, Shandong University, Jinan 250061 (China); Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Yujun, Zhang, E-mail: yujunzhangcn@163.com [Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials of Ministry of Education, Shandong University, Jinan 250061 (China); Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, Shandong University, Jinan 250061 (China)

    2017-04-30

    Highlights: • Phosphoryl functionalized mesoporous silica (TBP-SBA-15) is synthesized. • The amino and phosphoryl groups are successfully grafted on SBA-15. • TBP-SBA-15 has high and rapid uranium adsorption capacity in broad pH range. • The U(VI) adsorption of TBP-SBA-15 is spontaneous and belongs to chemical adsorption. - Abstract: Phosphoryl functionalized mesoporous silica (TBP-SBA-15) was synthesized by modified mesoporous silica with γ-amino propyl triethoxy silane and tributyl phosphate. The obtained samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), small angle X-ray diffraction (SAXRD), thermo-gravimetric/differential thermalanalyzer (TG/DTA), N{sub 2} adsorption–desorption (BET) and Fourier transform infrared spectroscopy (FT-IR) techniques. Results showed that TBP-SBA-15 had large surface areas with ordered channel structure. Moreover, the effects of adsorption time, sorbent dose, solution pH, initial uranium concentration and temperature on the uranium adsorption behaviors were investigated. TBP-SBA-15 showed a high uranium adsorption capacity in a broad range of pH values. The U(VI) adsorption rate of TBP-SBA-15 was fast and nearly achieved completion in 10 min with the sorbent dose of 1 g/L. The U(VI) adsorption of TBP-SBA-15 followed the pseudo-second-order kinetic model and Freundlich isotherm model, indicating that the process was belonged to chemical adsorption. Furthermore, the thermodynamic parameters (ΔG{sup 0}, ΔH{sup 0} and ΔS{sup 0}) confirmed that the adsorption process was endothermic and spontaneous.

  19. Liquid Photonic Crystals for Mesopore Detection.

    Zhu, Biting; Fu, Qianqian; Chen, Ke; Ge, Jianping

    2018-01-02

    Nitrogen adsorption-desorption for mesopore characterization requires the using of expensive instrumentation, time-consuming processes, and the consumption of liquid nitrogen. Herein, a new method is developed to measure the pore parameters through mixing a mesoporous substance with a supersaturated SiO 2 colloidal solution at different temperatures, and subsequent rapid measurement of reflection changes of the precipitated liquid photonic crystals. The pore volumes and diameters of mesoporous silica were measured according to the positive correlation between unit mass reflection change (Δλ/m) and pore volume (V), and the negative correlation between average absorption temperature (T) and pore diameter (D). This new approach may provide an alternative method for fast, convenient and economical characterization of mesoporous materials. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Carbon dioxide adsorption on micro-mesoporous composite materials of ZSM-12/MCM-48 type: The role of the contents of zeolite and functionalized amine

    Santos, S.C.G. [Federal University of Sergipe, Materials Science and Engineering Postgraduate Program P" 2CEM, São Cristovão/SE (Brazil); Pedrosa, A.M.Garrido [Federal University of Sergipe, Departament of Chemistry (DQI), São Cristovão/SE (Brazil); Souza, M.J.B., E-mail: mjbsufs@gmail.com [Federal University of Sergipe, Department of Chemical Engineering (DEQ), Av. Marechal Rondon S/N, 49100-000, São Cristovão/SE (Brazil); Cecilia, J.A.; Rodríguez-Castellón, E. [University of Málaga, Department of Inorganic Chemistry, Crystallography and Mineralogy, Faculty of Sciences, 29071, Málaga (Spain)

    2015-10-15

    Highlights: • Synthesis of the micro-mesoporous composite materials of ZSM-12/MCM-48 type. • Application of these adsorbents in the carbon dioxide adsorption. • Effects of the contents of zeolite and amino group in the material surface on the CO{sub 2} capture efficiency. - Abstract: In this study ZSM-12/MCM-48 adsorbents have been synthesized at three ZSM-12 content, and also were functionalizated with amine groups by grafting. All the adsorbents synthesized were evaluated for CO{sub 2} capture. The X-ray diffraction analysis of the ZSM-12/MCM-48 composite showed the main characteristic peaks of ZSM-12 and MCM-48, and after the functionalization, the structure of MCM-48 on the composite impregnated was affected due amine presence. For the composites without amine, the ZSM-12 content was the factor determining in the adsorption capacity of CO{sub 2} and for the composites with amine the amount of amine was that influenced in the adsorption capacity.

  1. Preparation and physical characterization of calcium sulfate cement/silica-based mesoporous material composites for controlled release of BMP-2

    Tan H

    2015-07-01

    Full Text Available Honglue Tan,1 Shengbing Yang,2 Pengyi Dai,1 Wuyin Li,1 Bing Yue2 1Luoyang Orthopedics and Traumatology Institution, Luoyang Orthopedic-Traumatological Hospital, Luoyang, 2Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China Abstract: As a commonly used implant material, calcium sulfate cement (CSC, has some shortcomings, including low compressive strength, weak osteoinduction capability, and rapid degradation. In this study, silica-based mesoporous materials such as SBA-15 were synthesized and combined with CSC to prepare CSC/SBA-15 composites. The properties of SBA-15 were characterized by X-ray diffraction, transmission electron microscopy, and nitrogen adsorption–desorption isotherms. SBA-15 was blended into CSC at 0, 5, 10, and 20 wt%, referred to as CSC, CSC-5S (5% mass ratio, CSC-10S (10% mass ratio, and CSC-20S (20% mass ratio, respectively. Fourier-transform infrared spectroscopy and compression tests were used to determine the structure and mechanical properties of the composites, respectively. The formation of hydroxyapatite on composite surfaces was analyzed using scanning electron microscopy and X-ray diffraction after soaking in simulated body fluid. BMP-2 was loaded into the composites by vacuum freeze-drying, and its release characteristics were detected by Bradford protein assay. The in vitro degradation of the CSC/SBA-15 composite was investigated by measuring weight loss. The results showed that the orderly, nanostructured, mesoporous SBA-15 possessed regular pore size and structure. The compressive strength of CSC/SBA-15 increased with the increase in SBA-15 mass ratio, and CSC-20S demonstrated the maximum strength. Compared to CSC, hydroxyapatite that formed on the surfaces of CSC/SBA-15 was uniform and compact. The degradation rate of CSC/SBA-15 decreased with increasing

  2. Functionalized bimodal mesoporous silicas as carriers for controlled aspirin delivery

    Gao, Lin; Sun, Jihong; Li, Yuzhen

    2011-08-01

    The bimodal mesoporous silica modified with 3-aminopropyltriethoxysilane was performed as the aspirin carrier. The samples' structure, drug loading and release profiles were characterized with X-ray diffraction, scanning electron microscopy, N 2 adsorption and desorption, Fourier transform infrared spectroscopy, TG analysis, elemental analysis and UV-spectrophotometer. For further exploring the effects of the bimodal mesopores on the drug delivery behavior, the unimodal mesoporous material MCM-41 was also modified as the aspirin carrier. Meantime, Korsmeyer-Peppas equation ft= ktn was employed to analyze the dissolution data in details. It is indicated that the bimodal mesopores are beneficial for unrestricted drug molecules diffusing and therefore lead to a higher loading and faster releasing than that of MCM-41. The results show that the aspirin delivery properties are influenced considerably by the mesoporous matrix, whereas the large pore of bimodal mesoporous silica is the key point for the improved controlled-release properties.

  3. Mesoporous zeolite and zeotype single crystals synthesized in fluoride media

    Egeblad, Kresten; Kustova, Marina; Klitgaard, Søren Kegnæs

    2007-01-01

    We report the synthesis and characterization of a series of new mesoporous zeolite and zeotype materials made available by combining new and improved procedures for directly introducing carbon into reaction mixtures with the fluoride route for conventional zeolite synthesis. The mesoporous...... materials were all prepared by hydrothermal crystallization of gels adsorbed on carbon matrices which were subsequently removed by combustion. The procedures presented here resulted in mesoporous zeolite and zeotypes materials with MFI, MEL, BEA, AFI and CHA framework structures. All samples were...... characterized by XRPD, SEM, TEM and N-2 physisorption measurements. For the zeolite materials it A as found that mesoporous MFI and MEL structured single crystals could indeed be crystallized from fluoride media using an improved carbon-templating approach. More importantly, it was found that mesoporous BEA...

  4. Tunable conductivity in mesoporous germanium

    Beattie, Meghan N.; Bioud, Youcef A.; Hobson, David G.; Boucherif, Abderraouf; Valdivia, Christopher E.; Drouin, Dominique; Arès, Richard; Hinzer, Karin

    2018-05-01

    Germanium-based nanostructures have attracted increasing attention due to favourable electrical and optical properties, which are tunable on the nanoscale. High densities of germanium nanocrystals are synthesized via electrochemical etching, making porous germanium an appealing nanostructured material for a variety of applications. In this work, we have demonstrated highly tunable electrical conductivity in mesoporous germanium layers by conducting a systematic study varying crystallite size using thermal annealing, with experimental conductivities ranging from 0.6 to 33 (×10‑3) Ω‑1 cm‑1. The conductivity of as-prepared mesoporous germanium with 70% porosity and crystallite size between 4 and 10 nm is shown to be ∼0.9 × 10‑3 Ω‑1 cm‑1, 5 orders of magnitude smaller than that of bulk p-type germanium. Thermal annealing for 10 min at 400 °C further reduced the conductivity; however, annealing at 450 °C caused a morphological transformation from columnar crystallites to interconnecting granular crystallites and an increase in conductivity by two orders of magnitude relative to as-prepared mesoporous germanium caused by reduced influence of surface states. We developed an electrostatic model relating the carrier concentration and mobility of p-type mesoporous germanium to the nanoscale morphology. Correlation within an order of magnitude was found between modelled and experimental conductivities, limited by variation in sample uniformity and uncertainty in void size and fraction after annealing. Furthermore, theoretical results suggest that mesoporous germanium conductivity could be tuned over four orders of magnitude, leading to optimized hybrid devices.

  5. Functionalized Mesoporous Silica Membranes for CO2 Separation Applications

    Hyung-Ju Kim

    2015-01-01

    Full Text Available Mesoporous silica molecular sieves are emerging candidates for a number of potential applications involving adsorption and molecular transport due to their large surface areas, high pore volumes, and tunable pore sizes. Recently, several research groups have investigated the potential of functionalized mesoporous silica molecular sieves as advanced materials in separation devices, such as membranes. In particular, mesoporous silica with a two- or three-dimensional pore structure is one of the most promising types of molecular sieve materials for gas separation membranes. However, several important challenges must first be addressed regarding the successful fabrication of mesoporous silica membranes. First, a novel, high throughput process for the fabrication of continuous and defect-free mesoporous silica membranes is required. Second, functionalization of mesopores on membranes is desirable in order to impart selective properties. Finally, the separation characteristics and performance of functionalized mesoporous silica membranes must be further investigated. Herein, the synthesis, characterization, and applications of mesoporous silica membranes and functionalized mesoporous silica membranes are reviewed with a focus on CO2 separation.

  6. Research Progress on Synthesis of Lignin-derived Mesoporous Carbon Materials via Template Strategy%模板法制备木质素基中孔炭材料研究进展

    宋曜光; 刘军利; 许伟; 孙康

    2018-01-01

    Lignin is one of the three recalcitrant components of lignocellulosic renewable biomass and the most abundant heterogeneous aromatic structural biopolymer on the earth. Lignin has a high carbon content over 50 %,and is one of the potential ideal precursors for carbon materials.Mesoporous carbon with high specific surface area and big pore size has wide applications on biomedical devices, catalysis, supercapacitors and so on. Therefore, the synthesis of mesoporous carbon materials has successfully concentrated attention and efforts by scientists worldwide. Nano-casting techniques are available method to prepare mesoporous carbons. Herein, some common strategies for pore dimension adjusting such as hard template route, soft template route and dual template route were reviewed.Finally,the recent research progress on the preparation of lignin-derived mesoporous carbon materials by using template strategy was emphatically introduced.%木质素是3种木质纤维类可再生生物质资源之一,同时是自然界中含量最丰富的芳香类天然高分子聚合物,其含碳量超过50 %,是制备炭材料的理想前驱体.中孔炭材料具有比表面积高、孔径大等特点,在医学器件、催化、超级电容器等方面有着广泛的应用,模板法是制备中孔炭材料的常用方法.主要介绍以木质素为碳前驱体通过硬模板法、软模板法以及双模板法制备中孔炭材料并调控孔结构,重点介绍了制备最新进展.

  7. Dual layer hollow fiber sorbents for trace H2S removal from gas streams

    Bhandari, Dhaval A.; Bessho, Naoki; Koros, William J.

    2013-01-01

    Hollow fiber sorbents are pseudo monolithic materials with potential use in various adsorption based applications. Dual layer hollow fiber sorbents have the potential to allow thermal regeneration without direct contact of the regeneration fluid with the sorbent particles. This paper considers the application of dual layer hollow fiber sorbents for a case involving trace amounts of H2S removal from a simulated gas stream and offers a comparison with single layer hollow fiber sorbents. The effect of spin dope composition and core layer zeolite loading on the gas flux, H2S transient sorption capacity and pore structure are also studied. This work can be used as a guide to develop and optimize dual layer hollow fiber sorbent properties beyond the specific example considered here. © 2013 Elsevier Ltd.

  8. Dual layer hollow fiber sorbents for trace H2S removal from gas streams

    Bhandari, Dhaval A.

    2013-05-01

    Hollow fiber sorbents are pseudo monolithic materials with potential use in various adsorption based applications. Dual layer hollow fiber sorbents have the potential to allow thermal regeneration without direct contact of the regeneration fluid with the sorbent particles. This paper considers the application of dual layer hollow fiber sorbents for a case involving trace amounts of H2S removal from a simulated gas stream and offers a comparison with single layer hollow fiber sorbents. The effect of spin dope composition and core layer zeolite loading on the gas flux, H2S transient sorption capacity and pore structure are also studied. This work can be used as a guide to develop and optimize dual layer hollow fiber sorbent properties beyond the specific example considered here. © 2013 Elsevier Ltd.

  9. Engineered sorbent barriers for low-level waste disposal

    Mitchell, S.J.; Freeman, H.D.; Buelt, J.L.

    1986-01-01

    Pacific Northwest Laboratory is developing sorbent materials to prevent the migration of radionuclides from low-level waste sites. These materials would allow water to pass, preventing the bathtub effect at humid sites. Screening studies identified promising sorbent materials for three key radionuclides: for cesium, greensand; for cobalt, activated charcoal; and for strontium, synthetic zeolite or clinoptilolite. Mixtures of these sorbent materials were tested in 0.6-m-diameter columns using radioactive leachates. To simulate expected worst-case conditions, the leachate solution contained the radionuclides, competing cations, and a chelating agent, adjusted to a pH of 5. A sorbent barrier comprised of greensand (1 wt %), activated charcoal (6 wt %), synthetic zeolite (20 wt %), and soil (73 wt %) achieved the decontamination factors necessary to meet the regulatory performance requirements established for this study. Sorbent barriers can be applied to shallow land burial, as backfill around the waste or engineered structures, or as backup to other liner systems. 2 refs., 6 figs., 3 tabs

  10. Research on using Mineral Sorbents for A Sorption Process in the Environment Contaminated with Petroleum Substances

    Pijarowski Piotr Marek

    2014-06-01

    Full Text Available A research on diatomite sorbents was carried out to investigate their ability to remove hazardous substances from oil spillages. We used two types of sorbents available on the market with differences in material density and particles size of composition. As sorbents we used Ekoterm oil and unleaded petrol 95 coming from refinery PKN Orlen S.A. Two types of sorbents with similar chemical composition but different granulometric composition were used. They are marked as D1 and C1 samples. The fastest absorbent was C1, but D1 sample was the most absorptive.

  11. Comparison of different mesoporous silicas for off-line solid phase extraction of 17β-estradiol from waters and its determination by HPLC-DAD.

    Gañán, Judith; Pérez-Quintanilla, Damián; Morante-Zarcero, Sonia; Sierra, Isabel

    2013-09-15

    Functionalized (SBA-C₁₈ and SM-C₁₈) and non-functionalized (SBA-15 and SM) mesoporous silicas were then examined as sorbents for solid-phase extraction of 17β-estradiol in aqueous media. Experiments were run in order to test critical factors affecting the procedure extraction efficiency, including the type of sorbent, the analyte concentration, the solvent and volume used for elution and the sample volume. Among the prepared materials, SBA-C₁₈ had the highest adsorption affinity towards 17β-estradiol and under optimized conditions (200mg of sorbent, 150 mL of water sample, elution with 3 × 2 mL of methanol) this sorbent proved good extraction capacity and elution efficiency for this hormone from aqueous media (recovery near 100%). To evaluate the analytical applicability of the proposed method, it was applied to the determination of 17β-estradiol in drinking water by high performance liquid chromatography with a photodiode array detector. Calibration curves were shown to be linear between 1.25 and 100 mg L(-1)with correlation coefficients ≥0.999 (n=5) for 17β-estradiol. The instrumental detection and quantitation limits calculated were 0.38 and 1.25 mg L(-1), respectively. The relative standard deviation obtained values were ≤3% and the mean recoveries obtained were of 82%. The results suggest that SBA-C18 is a promising material for the off-line solid phase extraction of 17β-estradiol from waters. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Hierarchical zeolites: progress on synthesis and characterization of mesoporous zeolite single crystal catalysts

    Kustova, Marina; Egeblad, Kresten; Christensen, Claus H.

    2007-01-01

    Recently, a new family of crystalline zeolitic materials was reported, the so-called mesoporous zeolite single crystals featuring individual zeolite single crystals with an additional noncrystalline mesopore system interconnected with the usual micropore system of the zeolite, resulting...... measurements. Additionally, the results of diffusion of n-hexadecane in conventional and mesoporous zeolites are presented. Isomerization and cracking of n-hexadecane was chosen as model test reaction for these materials. All results support that mesoporous zeolites are superior catalysts due to improved mass...... transport. Importantly, the mesoporous zeolites show significant improved resistance to poisoning by carbon formation....

  13. Peat hybrid sorbents for treatment of wastewaters and remediation of polluted environment

    Klavins, Maris; Burlakovs, Juris; Robalds, Artis; Ansone-Bertina, Linda

    2015-04-01

    For remediation of soils and purification of polluted waters, wastewaters, sorbents might be considered as an prospective group of materials and amongst them peat have a special role due to low cost, biodegradability, high number of functional groups, well developed surface area and combination of hydrophilic/hydrophobic structural elements. Peat as sorbent have good application potential for removal of trace metals, and we have demonstrated peat sorption capacities, sorption kinetics, thermodynamics in respect to metals with different valencies - Tl(I), Cu(II), Cr(III). However peat sorption capacity in respect to nonmetallic (anionic species) elements is low. Also peat mechanical properties do not support application in large scale column processes. To expand peat application possibilities the approach of biomass based hybrid sorbents has been elaborated. The concept "hybrid sorbent" in our understanding means natural, biomass based sorbent modified, covered with another sorbent material, thus combining two types of sorbent properties, sorbent functionalities, surface properties etc. As the "covering layer" both inorganic substances, mineral phases (iron oxohydroxides, oxyapatite) both organic polymers (using graft polymerization) were used. The obtained sorbents were characterised by their spectral properties, surface area, elemental composition. The obtained hybrid sorbents were tested for sorption of compounds in anionic speciation forms, for example of arsenic, antimony, tellurium and phosphorous compounds in comparison with weakly basic anionites. The highest sorption capacity was observed when peat sorbents modified with iron compounds were used. Sorption of different arsenic speciation forms onto iron-modified peat sorbents was investigated as a function of pH and temperature. It was established that sorption capacity increases with a rise in temperature, and the calculation of sorption process thermodynamic parameters indicates the spontaneity of sorption

  14. Template synthesis and characterization of nanostructured hierarchical mesoporous ribbon-like NiO as high performance electrode material for supercapacitor

    Yao, Mingming; Hu, Zhonghua; Xu, Zijie; Liu, Yafei; Liu, Peipei; Zhang, Qiang

    2015-01-01

    The ribbon-like NiO was synthesized by a hard-template method combining the calcination, using mesoporous carbon as a hard templat and guanidine hydrochloride as precipitant of weak base, respectively. The nanostructured hierarchical mesoporous ribbon-like NiO exhibits the high specific capacitance of 1260 F g −1 at the current density of 1 A g −1 , and 95% capacity retention at a current density of 10 A g −1 in a testing range of 5000 cycles. - Highlights: • Ribbon-like NiO was prepared by using mesoporous carbon as a hard template. • Typical ribbon-like NiO possesses the hierarchical mesoporous nanostructure. • High specific capacitance of 1260 F g −1 is obtained at a current density of 1 A g −1 . • Excellent electrochemical stability of 95% after 5000 charge–discharge cycles. - Abstract: In this paper, nanostructured hierarchical mesoporous ribbon-like NiO was synthesized by a hard-template method combining the calcination process. Nickel sulfate hexahydrate, guanidine hydrochloride and mesoporous carbon were used as nickel precursors, precipitant of weak base and template, respectively. The resultant NiO samples were characterized by Raman spectroscopy, energy dispersive spectrometer, X-ray diffraction, N 2 adsorption and desorption, scanning electron microscopy and transmission electron microscopy. The electrochemical performances were evaluated by cyclic voltammetry (CV), cyclic chronopotentiometry (CP) and electrochemical impedance spectroscopy (EIS) in 6 M KOH solution. The typical hierarchical mesoporous ribbon-like NiO shows a good electrochemical performance: a high specific capacitance of 1260 F g −1 at 1 A g −1 , 748 F g −1 at high current density of 20 A g −1 and 95% capacity retention at a current density of 10 A g −1 in a testing range of 5000 cycles

  15. Soft-Template-Synthesized Mesoporous Carbon for Oral Drug Delivery

    Saha, Dipendu [ORNL; Warren, Kaitlyn E [ORNL; Naskar, Amit K [ORNL

    2014-01-01

    Template-synthesized mesoporous carbons were successfully used in in vitro investigations of controlled delivery of three model drugs, captopril, furosemide, and ranitidine hydrochloride. Captopril and furosemide exhibited desorption kinetics over 30 40 h, and ranitidine HCl had a complete release time of 5 10 h. As evident from the slow release kinetics, we contend that our mesoporous carbon is an improved drug-delivery medium compared to state-of-the-art porous silica-based substrates. The mesoporous carbons, synthesized from phloroglucinol and lignin, a synthetic and a sustainable precursor, respectively, exhibit BET surface area of 200 400 m2 g-1 and pore volume of 0.2 0.6 cm3 g-1. The phloroglucinol-based carbon has narrower pore widths and higher pore volume than the lignin-derived counterpart and maintains a longer release time. Numerical modeling of the release kinetics data reveals that the diffusivities of all the drugs from lignin-based carbon media are of equivalent magnitude (10-22 to 10-24 m2 s-1). However, a tailored reduction of pore width in the sorbent reduces the diffusivity of smaller drug molecules (captopril) by an order of magnitude. Thus, engineered pore morphology in our synthesized carbon sorbent, along with its potential to tailor the chemistry of its interaction with sorbet, can be exploited for optimal delivery system of a preferred drug within its therapeutic level and below the level of toxicity.

  16. Oil spill sorbents: Testing protocol and certification listing program

    Cooper, D.; Gausemel, I.

    1993-01-01

    Environment Canada's Emergencies Engineering Division is spearheading a program in conjunction with the Canadian General Standards Board that would see the development of a certification and listing program in addition to a national standard for the testing of sorbent materials. Funding for this program is provided by Environment Canada (EC), Canadian Coast Guard (CCG), Marine Spill Response Corporation (MSRC), US Coast Guard (USCG), and US Minerals Management Service (MMS). The test methods are based upon those defined by the American Society for Testing and Materials and previous test methods developed by Environment Canada for our series of reports entitled Selection Criteria and Laboratory Evaluation of Oil Spill Sorbents. This series, which was started in 1975, encompasses a number of commercially available oil spill sorbents tested with different petroleum products and hydrocarbon solvents. The testing program will categorize the sorbents according to their operating characteristics. The main categories are oil spills on water, oil spills on land, and industrial use. The characteristics to be evaluated with the new test protocols include initial and maximum sorption capacities, water pickup, buoyancy, reuse potential, retention profile, disintegration (material integrity), and ease of application and retrieval. In the near future are plans to incorporate changes to the test that would involve increasing the list of test liquids to encompass spills in an industrial setting, in addition to testing sorbent booms and addressing the disposal problem

  17. Nanostructured Mesoporous Silicas for Bone Tissue Regeneration

    Isabel Izquierdo-Barba

    2008-01-01

    Full Text Available The research on the development of new biomaterials that promote bone tissue regeneration is receiving great interest by the biomedical scientific community. Recent advances in nanotechnology have allowed the design of materials with nanostructure similar to that of natural bone. These materials can promote new bone formation by inducing the formation of nanocrystalline apatites analogous to the mineral phase of natural bone onto their surfaces, i.e. they are bioactive. They also stimulate osteoblast proliferation and differentiation and, therefore, accelerate the healing processes. Silica-based ordered mesoporous materials are excellent candidates to be used as third generation bioceramics that enable the adsorption and local control release of biological active agents that promote bone regeneration. This local delivery capability together with the bioactive behavior of mesoporous silicas opens up promising expectations in the bioclinical field. In this review, the last advances in nanochemistry aimed at designing and tailoring the chemical and textural properties of mesoporous silicas for biomedical applications are described. The recent developed strategies to synthesize bioactive glasses with ordered mesopore arrangements are also summarized. Finally, a deep discussion about the influence of the textural parameters and organic modification of mesoporous silicas on molecules adsorption and controlled release is performed.

  18. Core-shelled mesoporous CoFe2O4-SiO2 material with good adsorption and high-temperature magnetic recycling capabilities

    Li, Zhi'ang; Wang, Jianlin; Liu, Min; Chen, Tong; Chen, Jifang; Ge, Wen; Fu, Zhengping; Peng, Ranran; Zhai, Xiaofang; Lu, Yalin

    2018-04-01

    Residues of organic dye in industrial effluents cause severe water system pollution. Although several methods, such as biodegradation and activated carbon adsorption, are available for treating these effluents before their discharge into waterbodies, secondary pollution by adsorbents and degrading products remains an issue. Therefore, new materials should be identified to solve this problem. In this work, CoFe2O4-SiO2 core-shell structures were synthesized using an improved Stöber method by coating mesoporous silica onto CoFe2O4 nanoparticles. The specific surface areas of the synthesized particles range from 30 m2/g to 150 m2/g and vary according to the dosage amount of tetraethoxysilane. Such core-shelled nanoparticles have the following advantages for treating industrial effluents mixed with dye: good adsorption capability, above-room-temperature magnetic recycling capability, and heat-enduring stability. Through adsorption of methylene blue, a typical dyeing material, the core-shell-structured particles show a good adsorption capability of approximately 33 mg/L. The particles are easily and completely collected by magnets, which is possible due to the magnetic property of core CoFe2O4. Heat treatment can burn out the adsorbed dyes and good adsorption performance is sustained even after several heat-treating loops. This property overcomes the common problem of particles with Fe3O4 as a core, by which Fe3O4 is oxidized to nonmagnetic α-Fe2O3 at the burning temperature. We also designed a miniature of effluent-treating pipeline, which demonstrates the potential of the application.

  19. Hollow mesoporous CuCo2O4 microspheres derived from metal organic framework: A novel functional materials for simultaneous H2O2 biosensing and glucose biofuel cell.

    Cui, Shiqiang; Gu, Shuqing; Ding, Yaping; Zhang, Jiangjiang; Zhang, Zhen; Hu, Zongqian

    2018-02-01

    Hollow mesoporous CuCo 2 O 4 (meso-CuCo 2 O 4 ) microspheres were successfully synthesized by decomposing metal-organic frameworks (MOFs) as the template. The as-prepared CuCo 2 O 4 microspheres were first simultaneously used for H 2 O 2 biosensing and glucose biofuel cell (GFC) as the enzyme mimic. The resulting of meso-CuCo 2 O 4 displayed not only excellent catalytic performances to H 2 O 2 including a super-fast response time (within 2s), a super-high sensitivity (654.23 μA mM -1 cm -2 ) and a super-low detection limit (3nM at S/N = 3) on the sensor, but also great values in GFC as anode material with an open circuit voltage of 0.85V, a maximum power density of 0.33 mWcm -2 and a limiting current density of 1.27 mAcm -2 , respectively. The preeminent catalytic abilities to H 2 O 2 and glucose may be attributed to the surpassing intrinsic catalytic activity of CuCo 2 O 4 and large specific area of mesoporous structure. These significant findings deriving from this work not only provided a novel exploration for the fabrication of hollow spherical mesoporous bimetallic oxides, but also promoted the development of the supersensitive detection of H 2 O 2 and non-enzymatic biofuel cell. Copyright © 2017. Published by Elsevier B.V.

  20. Adsorption of H2O and CO2 on supported amine sorbents

    Veneman, Rens; Frigka, Natalia; Zhao, Wenying; Li, Zhenshan; Kersten, Sascha R.A.; Brilman, Derk Willem Frederik

    2015-01-01

    In this work the adsorption of H2O and CO2 on Lewatit VP OC 1065 was studied in view of the potential application of this sorbent in post combustion CO2 capture. Both CO2 and H2O were found to adsorb on the amine active sites present on the pore surface of the sorbent material. However, where the

  1. Synthesis and test of sorbents based on calcium aluminates for SE-SR

    Barelli, L.; Bidini, G.; Di Michele, A.; Gallorini, F.; Petrillo, C.; Sacchetti, F.

    2014-01-01

    Highlights: • Synthesis strategy of CaO incorporation into calcium aluminates was approached. • Three innovative sorbents (M1, M2, M3) were synthesized and characterized. • Sorption capacity of developed sorbents was evaluated in multi-cycle processes. • M3 sorbent showed best performance, much higher than conventional CaO ones. • M3 sorbent functionality in SE-SR process was verified. - Abstract: Greenhouse gases emission of power generation plants will be continuously tightened to achieve European targets in terms of CO 2 emissions. In particular, the switching to a sustainable power generation using fossil fuels will be strongly encouraged in the future. In this context, sorption-enhanced steam reforming (SE-SR) is a promising process because it can be implemented as a CCS pre-combustion methodology. The purpose of this study is to develop and test innovative materials in order to overcome main limitations of standard CaO sorbent, usually used in the SE-SR process. The investigated innovative sorbents are based on incorporation of CaO particles into inert materials which significantly reduce the performance degradation. In particular, sorbent materials based on calcium aluminates were considered, investigating different techniques of synthesis. All synthesized materials were packed, together with the catalyst, in a fixed bed reactor and tested in sorption/regeneration cycles. Significant improvements were obtained respect to standard CaO regarding sorption capacity stability exhibited by the sorbent

  2. Quantitative analysis of flavanones from citrus fruits by using mesoporous molecular sieve-based miniaturized solid phase extraction coupled to ultrahigh-performance liquid chromatography and quadrupole time-of-flight mass spectrometry.

    Cao, Wan; Ye, Li-Hong; Cao, Jun; Xu, Jing-Jing; Peng, Li-Qing; Zhu, Qiong-Yao; Zhang, Qian-Yun; Hu, Shuai-Shuai

    2015-08-07

    An analytical procedure based on miniaturized solid phase extraction (SPE) and ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry was developed and validated for determination of six flavanones in Citrus fruits. The mesoporous molecular sieve SBA-15 as a solid sorbent was characterised by Fourier transform-infrared spectroscopy and scanning electron microscopy. Additionally, compared with reported extraction techniques, the mesoporous SBA-15 based SPE method possessed the advantages of shorter analysis time and higher sensitivity. Furthermore, considering the different nature of the tested compounds, all of the parameters, including the SBA-15 amount, solution pH, elution solvent, and the sorbent type, were investigated in detail. Under the optimum condition, the instrumental detection and quantitation limits calculated were less than 4.26 and 14.29ngmL(-1), respectively. The recoveries obtained for all the analytes were ranging from 89.22% to 103.46%. The experimental results suggested that SBA-15 was a promising material for the purification and enrichment of target flavanones from complex citrus fruit samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. IMMOBILIZATION OF MICROALGAE ON THE SURFACE OF NEW CROSS-LINKED POLYETHYLENIMINE-BASED SORBENTS.

    Vasilieva, Svetlana; Shibzukhova, Karina; Morozov, Alexey; Solovchenko, Alexei; Bessonov, Ivan; Kopitsyna, Maria; Lukyanov, Alexander; Chekanov, Konstantin; Lobakova, Elena

    2018-04-11

    We report on the use of the polyethylenimine-based (PEI) sorbents for immobilization and harvesting of microalgae (MA) cells. Specific materials assessed were porous solid polymers from highly-branched PEI synthesized by cross-linking with epichlorohydrin (ECH) or diethylene glycol diglycidyl ether (DGDE). We estimated the effect of PEI/cross-linker ratio on the MA attachment and biocompatibility of the sorbents with the MA cells. A decrease in the cross-linker percentage resulted in the enhancement of the immobilization efficiency but impaired the cell viability as was manifested by inhibition of the photosynthetic activity of the MA cells. The rate of Chlorella vulgaris cell attachment to the sorbents with ECH was faster as compared to that of the PEI-DGDE-based polymers. The cells immobilized on the PEI-ECH sorbents showed a more profound decline in their viability (assessed via photosynthetic activity). The sorbents with 60% of DGDE were characterized by high immobilization efficiency. These sorbents supported a prolonged cultivation of the immobilized MA without impairing their viability and metabolic activity. We conclude that the sorbents with a lower percentage of DGDE (<30%) and sorbents with ECH are suitable for harvesting of the MA cells intended for immediate downstream processing, potentially without the cell desorption. To the best of our knowledge, this is the first report on successful application of PEI-based sorbents in microalgal biotechnology. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Cheap carbon sorbents produced from lignite by catalytic pyrolysis

    Kuznetsov, B.N.; Schchipko, M.L. [Inst. of Chemistry of Natural Organic Materials, Akademgorodok, Krasnoyarsk (Russian Federation)

    1995-12-01

    Some data are presented describing the new technology of carbon sorbent production from powdered lignite in the installation with fluidized bed of catalyst. It was shown the different types of char products with extended pore structure and high sorption ability can be produced from cheap and accessible lignite of Kansk-Achinsk coal pit in pilot installation with fluidized bed of Al-Cu-Cr oxide catalyst or catalytically active slag materials. In comparison with the conventional technologies of pyrolysis the catalytic pyrolysis allows to increase by 3-5 times the process productivity and to decrease significantly the formation of harmful compounds. The latter is accomplished by complete oxidation of gaseous pyrolysis products in the presence of catalysts and by avoiding the formation of pyrolysis tars - the source of cancerogenic compounds. The technology of cheap powdered sorbent production from lignites makes possible to obtain from lignite during the time of pyrolysis only a few seconds char products with porosity up to 0.6 cm{sup 3} /g, and specific surface area more than 400 m{sup 3} /g. Some methods of powdered chars molding into carbon materials with the different shape were proved for producing of firmness sorbents. Cheap carbon sorbents obtained by thermocatalytic pyrolysis can be successfully used in purification of different industrial pollutants as one-time sorbent or as adsorbents of long-term application with periodic regeneration.

  5. Ecologically pure sorbents for power system of Myanmar

    Nikitina, I. S.; Moryganova, Y. A.; Maung, Ko Ko; Arefeva, E. A.

    2017-11-01

    Currently, one of the most important problems of the thermal power plant, and many industrial enterprises in different countries is a wastewater treatment for oil products. When choosing the good sorbents is necessary to consider not only the properties and efficiency of the recommended materials, but also the cost, the possibility of environmentally friendly disposal of used sorbents and the possibility of using secondary resources. The purpose of this paper is to study the possibility of using agricultural waste in Myanmar as the sorbents in wastewater treatment containing oil products. The results of experiments have confirmed that rice hulls, and coconut fiber can be effectively used as the sorbents in wastewater treatment containing oil products at concentrations up to 10 mg/l. According to comparative analysis with the conventional sorbent-activated birch carbon (BAC-A) in the Russian power industry has shown that coconut fiber has very good sorption capacity and it is available to use as the raw materials for industries, which does not require to regenerate after using it and can be directly recycled in the factory.

  6. Dual layer hollow fiber sorbents: Concept, fabrication and characterization

    Bhandari, Dhaval

    2013-02-01

    Hollow fiber sorbents are pseudo-monolithic separations materials created with fiber spinning technology using a polymer \\'binder\\', impregnated with high loadings of sorbent \\'fillers\\' [1]. To increase purified gas recovery during the sorption step and to ensure consistent sorption capacity over repeated cycles, a dense, thin polymer barrier layer on the fiber sorbents is needed to allow only thermal interactions between the sorbate loaded layer and the thermal regeneration fluid. This paper considers materials and methods to create delamination-free dual layer fiber sorbents, with a porous core and a barrier sheath layer formed using a simultaneous co-extrusion process. Low permeability polymers were screened for sheath layer creation, with the core layer comprising cellulose acetate polymer as binder and zeolite NaY as sorbent fillers. Appropriate core and sheath layer dope compositions were determined by the cloud-point method and rheology measurements. The morphology of the as-spun fibers was characterized in detail by SEM, EDX and gas permeation analysis. A simplified qualitative model is described to explain the observed fiber morphology. The effects of core, sheath spin dope and bore fluid compositions, spinning process parameters such as air-gap height, spin dope and coagulation bath temperatures, and elongation draw ratio are examined in detail. © 2012 Elsevier B.V. All rights reserved.

  7. Sorbent application on the base of chitosan for radionuclides separation

    Pivarciova, L.

    2016-01-01

    Radioactive waste contains enormous amounts of radionuclides, which pollute the environment and can cause serious chemical and radiological toxicity threats to lower and higher living organism. Alternative process for the removal of heavy metal ions and radionuclides is sorption, which utilizes various certain natural materials of biological origin. Amino-polysaccharide-based sorbents e.g. chitosan represent suitable materials for binding of metal oxo-anion species because of numerous functional groups -OH and -NH_2 because of their suitable H-bond donor and acceptor sites. The sorbents on the base chitosan prepared through chemical modification were used for removal and separation certain radionuclides from aqueous media. The aim of this work was the study of physicochemical properties of prepared sorbents. The specific surface of sorbents was characterized with BET methods. Point of zero charge was identified with potentiometric titration. The size of particles and shape of sorbents were determined by scanning electron microscope. The sorption experiments for selected radionuclides were conducted under static and dynamic conditions. The effect of various parameters on the sorption "9"9"mTc, "6"0Co and the effect of pH on the separation of radionuclide mixture in the solution were studied. (author)

  8. Ultrathin mesoporous Co{sub 3}O{sub 4} nanosheets-constructed hierarchical clusters as high rate capability and long life anode materials for lithium-ion batteries

    Wu, Shengming [Key Laboratory of Functional Inorganic Materials Chemistry, Ministry of Education, School of Chemistry, Chemical Engineering and Materials, Heilongjiang University, Heilongjiang, Harbin 150080 (China); Xia, Tian, E-mail: xiatian@hlju.edu.cn [Key Laboratory of Functional Inorganic Materials Chemistry, Ministry of Education, School of Chemistry, Chemical Engineering and Materials, Heilongjiang University, Heilongjiang, Harbin 150080 (China); Wang, Jingping [Key Laboratory of Superlight Material and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Heilongjiang, Harbin 150001 (China); Lu, Feifei [Key Laboratory of Functional Inorganic Materials Chemistry, Ministry of Education, School of Chemistry, Chemical Engineering and Materials, Heilongjiang University, Heilongjiang, Harbin 150080 (China); Xu, Chunbo [Key Laboratory of Superlight Material and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Heilongjiang, Harbin 150001 (China); Zhang, Xianfa; Huo, Lihua [Key Laboratory of Functional Inorganic Materials Chemistry, Ministry of Education, School of Chemistry, Chemical Engineering and Materials, Heilongjiang University, Heilongjiang, Harbin 150080 (China); Zhao, Hui, E-mail: zhaohui98@yahoo.com [Key Laboratory of Functional Inorganic Materials Chemistry, Ministry of Education, School of Chemistry, Chemical Engineering and Materials, Heilongjiang University, Heilongjiang, Harbin 150080 (China)

    2017-06-01

    Graphical abstract: Ultrathin mesoporous Co{sub 3}O{sub 4} nanosheets-constructed hierarchical clusters (UMCN-HCs) have been successfully synthesized via a facile hydrothermal method followed by a subsequent thermolysis treatment. When tested as anode materials for LIBs, UMCN-HCs achieve high reversible capacity, good long cycling life, and rate capability. - Highlights: • UMCN-HCs show high capacity, excellent stability, and good rate capability. • UMCN-HCs retain a capacity of 1067 mAh g{sup −1} after 100 cycles at 100 mA g{sup −1}. • UMCN-HCs deliver a capacity of 507 mAh g{sup −1} after 500 cycles at 2 A g{sup −1}. - Abstract: Herein, Ultrathin mesoporous Co{sub 3}O{sub 4} nanosheets-constructed hierarchical clusters (UMCN-HCs) have been successfully synthesized via a facile hydrothermal method followed by a subsequent thermolysis treatment at 600 °C in air. The products consist of cluster-like Co{sub 3}O{sub 4} microarchitectures, which are assembled by numerous ultrathin mesoporous Co{sub 3}O{sub 4} nanosheets. When tested as anode materials for lithium-ion batteries, UMCN-HCs deliver a high reversible capacity of 1067 mAh g{sup −1} at a current density of 100 mA g{sup −1} after 100 cycles. Even at 2 A g{sup −1}, a stable capacity as high as 507 mAh g{sup −1} can be achieved after 500 cycles. The high reversible capacity, excellent cycling stability, and good rate capability of UMCN-HCs may be attributed to their mesoporous sheet-like nanostructure. The sheet-layered structure of UMCN-HCs may buffer the volume change during the lithiation-delithiation process, and the mesoporous characteristic make lithium-ion transfer more easily at the interface between the active electrode and the electrolyte.

  9. Sol–gel one-pot synthesis in soft conditions of mesoporous silica materials ready for drug delivery system

    Tourne-Peteilh, C.; Begu, S.; Lerner, D.A.; Galarneau, A.; Lafont, U.; Devoiselle, J.M.

    2011-01-01

    The present work reveals a new and simple strategy, a one-step sol–gel procedure, to encapsulate a low water-soluble drug in silica mesostructured microparticles and to improve its release in physiological media. The synthesis of these new materials is based on the efficient solubilisation of a

  10. Acidic and catalytic properties of hierarchical zeolites and hybrid ordered mesoporous materials assembled from MFI protozeolitic units

    Serrano, D. P.; García, R. A.; Vicente, G.; Linares, M.; Vitvarová, Dana; Čejka, Jiří

    2011-01-01

    Roč. 279, č. 2 (2011), s. 366-380 ISSN 0021-9517 Institutional research plan: CEZ:AV0Z40400503 Keywords : hierarchical zeolites * hybrid zeolitic-mesostructured materials * Bronsted and Lewis acid centres Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 6.002, year: 2011

  11. Performance of Zn-Fe-Mn/MCM-48 sorbents for high temperature H2S removal and analysis of regeneration process

    Huang, Z. B.; Liu, B. S.; Wang, F.; Amin, R.

    2015-10-01

    MCM-48 was synthesized using a rapid and facile process at room temperature. A series of 50%Zn-Fe-Mn/MCM-48 sorbents were prepared and their performance of hot coal gas desulfurization was investigated. High breakthrough sulfur capacity (13.2 g-S/100 g sorbent) and utilization (66.1%) of 50%1Zn2Fe2Mn/MCM-48 sorbent at 550 °C was achieved. The characterization results of XRD, BET, TPR and FT-IR revealed that MCM-48 had excellent thermal stability at less than 700 °C, ZnMn2O4 and (Mn, Zn)Fe2O4 were mainly active particles in fresh sorbents which were highly dispersed on support. The MCM-48 mesoporous structure remained intact after eight successive desulfurization/regeneration cycles. The regeneration process of 50%1Zn2Fe2Mn/MCM-48 sorbent was analyzed, it indicated that the breakthrough sulfur capacity decline of sorbent was due to the migration of Zn onto the sorbent surface and Zn accumulated on the surface and vaporized to the exterior from the surface. In the TPO test, the oxidation of Zn was different for 50%Zn/MCM-48 at 700 °C. It revealed that the temperature of regeneration for ZnO sorbent should be higher than 700 °C.

  12. Direct access to mesoporous crystalline TiO2/carbon composites with large and uniform pores for use as anode materials in lithium ion batteries

    Lee, J.; Jung, Y.S.; Warren, S.C.; Kamperman, M.M.G.; Oh, S.M.; DiSalvo, F.J.; Wiesner, U.

    2011-01-01

    Mesoporous and highly crystalline TiO2 (anatase)/carbon composites with large (>5¿nm) and uniform pores were synthesized using PI-b-PEO block copolymers as structure directing agents. Pore sizes could be tuned by utilizing block copolymers with different molecular weights. The resulting

  13. Crystalline mesoporous zirconia catalysts having stable tetragonal pore wall structure

    Sachtler, W.M.H.; Huang, Y.Y.

    1998-07-28

    Methods are disclosed for the preparation of new sulfated mesoporous zirconia materials/catalysts with crystalline pore walls of predominantly tetragonal crystal structure, characterized by nitrogen physical sorption measurement, X-ray diffraction, transmission electron microscopy and catalytic tests using n-butane isomerization to iso-butane and alkylation of 1-naphthol with 4-tert-butylstyrene as probe reactions. Sulfate deposition is preferred for the transformation of a mesoporous precursor with amorphous pore walls into a material with crystalline pore walls maintaining the mesoporous characteristics. 17 figs.

  14. Anionic sorbents for arsenic and technetium species

    Lucero, Daniel A.; Moore, Robert Charles; Bontchev, Ranko Panayotov; Hasan, Ahmed Ali Mohamed; Zhao, Hongting; Salas, Fred Manuel; Holt, Kathleen Caroline

    2003-01-01

    Two sorbents, zirconium coated zeolite and magnesium hydroxide, were tested for their effectiveness in removing arsenic from Albuquerque municipal water. Results for the zirconium coated zeolite indicate that phosphate present in the water interfered with the sorption of arsenic. Additionally, there was a large quantity of iron and copper present in the water, corrosion products from the piping system, which may have interfered with the uptake of arsenic by the sorbent. Magnesium hydroxide has also been proven to be a strong sorbent for arsenic as well as other metals. Carbonate, present in water, has been shown to interfere with the sorption of arsenic by reacting with the magnesium hydroxide to form magnesium carbonate. The reaction mechanism was investigated by FT-IR and shows that hydrogen bonding between an oxygen on the arsenic species and a hydrogen on the Mg(OH)2 is most likely the mechanism of sorption. This was also confirmed by RAMAN spectroscopy and XRD. Technetium exists in multiple oxidation states (IV and VII) and is easily oxidized from the relatively insoluble Tc(IV) form to the highly water soluble and mobile Tc(VII) form. The two oxidation states exhibit different sorption characteristics. Tc(VII) does not sorb to most materials whereas Tc(IV) will strongly sorb to many materials. Therefore, it was determined that it is necessary to first reduce the Tc (using SnCl2) before sorption to stabilize Tc in the environment. Additionally, the effect of carbonate and phosphate on the sorption of technetium by hydroxyapatite was studied and indicated that both have a significant effect on reducing Tc sorption

  15. Selective adsorption and release of cationic organic dye molecules on mesoporous borosilicates

    Paul, Manidipa; Pal, Nabanita; Bhaumik, Asim

    2012-01-01

    Mesoporous materials can play a pivotal role as a host material for delivery application to a specific part of a system. In this work we explore the selective adsorption and release of cationic organic dye molecules such as safranine T (ST) and malachite green (MG) on mesoporous borosilicate materials. The mesoporous silica SBA-15 and borosilicate materials (MBS) were prepared using non-ionic surfactant Pluronic P123 as template via evaporation induced self-assembly (EISA) method. After template removal the materials show high surface areas and in some cases ordered mesopores of dimensions ca. 6–7 nm. High surface area, mesoporosity and the presence of heteroatom (boron) help this mesoporous borosilicate material to adsorb high amount of cationic dye molecules at its surface from the respective aqueous solutions. Furthermore, the mesoporous borosilicate samples containing higher percentage adsorbed dyes show excellent release of ST or MG dye in simulated body fluid (SBF) solution at physiological pH = 7.4 and temperature 310 K. The adsorption and release efficiency of mesoporous borosilicate samples are compared with reference boron-free mesoporous pure silica material to understand the nature of adsorbate–adsorbent interaction at the surfaces. - Graphical abstract: Highly ordered 2D-hexagonal mesoporous borosilicate materials have been synthesized by using Pluronic P123 as template. The materials show very good adsorption and release of organic cationic dye molecules under physiological conditions. Highlights: ► Highly ordered 2D-hexagonal mesoporous borosilicate. ► Nonionic Pluoronic P123 templated mesoporous material. ► Adsorption of organic dyes at the mesopore surface. ► Controlled release of dyes under physiological pH and temperature. ► Release of safranine T (ST) and malachite green (MG) dyes in simulated body fluids.

  16. Mixed and Doped Solid Sorbents for CO2 Capture Applications

    Duan, Yuhua [National Energy Technology Lab. (NETL), Albany, OR (United States)

    2016-06-14

    The objectives of this presentation are to capture CO2 we need materials with optimal performance and low costs; establish a theoretical procedure to identify most potential candidates of CO2 solid sorbents from a large solid material databank; computational synthesis new materials to fit industrial needs; and explore the optimal working conditions for the promised CO2 solid sorbents, especially from room to warm T ranges with optimal energy usage.

  17. Catalytic properties and acidity of modified MCM-41 mesoporous materials with low Si/Al ratio: heptane isomerisation

    Ahmed Belhakem

    2006-06-01

    Full Text Available The catalytic properties and acidity of modified MCM-41 with a low Si/Al ratio and 0-95% NH4+ exchange were investigated. The samples were characterised by X-ray diffraction, scanning and transmission electron microscopy, and nitrogen adsorption. The acidity was studied by pyridine adsorption, temperature programmed desorption (TPD of ammonia, and infrared (IR spectroscopy. Adsorption of pyridine and IR spectroscopy indicated various types of Lewis and Brönsted acid sites. The density distribution of acid sites was determined by TPD. Both Lewis and Brönsted acid sites were found to be active in the heptane isomerisation. The presence of aluminium (low Si/Al combined to the ionic exchange between Na+ and NH4+ increases the acidity of MCM-41 materials. A close correlation between acidity and isomerisation was observed. Coke deposition, which reduces the activity, was also studied.

  18. Mesoporous titanium phosphates and related molecular sieves ...

    Unknown

    phosphate using a dilute H2O2 oxidant supports the tetrahedral coordination of Ti in ... production of H2 by photo-reduction of water under UV light irradiation. ... have been extensively studied and used as acid catalysts, adsorbents and ion ... mesoporous silica materials is also of outstanding interest because of their ...

  19. Experimental research on combustion fluorine retention using calcium-based sorbents during coal combustion (II)

    Qi, Q.; Ma, X.; Liu, J.; Wu, X.; Zhou, J.; Cen, K. [Liaoning Technical University, Fuxin (China). College of Resource and Environment Engineering

    2008-12-15

    Fluoride pollution produced by coal burning can be controlled with the calcium-based sorbent combustion fluorine technique in which calcium-based sorbents are mixed with the coal or sprayed into the combustion chamber. In a fixed bed tube furnace combustion experiment using one calcium-based natural mineral, limestone and one calcium-based building material, it was shown that the calcium-based sorbent particle grain size and pore structure have a big influence on the combustion fluorine retention effect. Reducing the calcium-based sorbent particle grain size and improving the calcium sorbent structure characteristics at very high temperature to enhance the fluorine retention effect is the important approach to the fluorine retention agent development. 8 refs., 1 fig., 5 tabs.

  20. Mesoporous yttria-zirconia and metal-yttria-zirconia solid solutions for fuel cells

    Mamak, M.; Coombs, N.; Ozin, G. [Toronto Univ., ON (Canada). Dept. of Chemistry

    2000-02-03

    A new class of binary mesoporous yttria-zirconia (YZ) and ternary mesoporous metal-YZ materials (M = electroactive Ni/Pt) is presented here that displays the highest surface area of any known form of yttria-stabilized zirconia. These mesoporous materials form as solid solutions and retain their structural integrity to 800 C, which bodes well for their possible utilization in fuel cells. (orig.)

  1. Octahedral molecular sieve sorbents and catalysts

    Li, Liyu [Richland, WA; King, David L [Richland, WA

    2010-04-20

    Octahedral molecular sieve sorbents and catalysts are disclosed, including silver hollandite and cryptomelane. These materials can be used, for example, to catalyze the oxidation of CO.sub.x (e.g., CO), NO.sub.x (e.g., NO), hydrocarbons (e.g., C.sub.3H.sub.6) and/or sulfur-containing compounds. The disclosed materials also may be used to catalyze other reactions, such as the reduction of NO.sub.2. In some cases, the disclosed materials are capable of sorbing certain products from the reactions they catalyze. Silver hollandite, in particular, can be used to remove a substantial portion of certain sulfur-containing compounds from a gas or liquid by catalysis and/or sorption. The gas or liquid can be, for example, natural gas or a liquid hydrocarbon.

  2. Mesoporous silica formulation strategies for drug dissolution enhancement: a review.

    McCarthy, Carol A; Ahern, Robert J; Dontireddy, Rakesh; Ryan, Katie B; Crean, Abina M

    2016-01-01

    Silica materials, in particular mesoporous silicas, have demonstrated excellent properties to enhance the oral bioavailability of poorly water-soluble drugs. Current research in this area is focused on investigating the kinetic profile of drug release from these carriers and manufacturing approaches to scale-up production for commercial manufacture. This review provides an overview of different methods utilized to load drugs onto mesoporous silica carriers. The influence of silica properties and silica pore architecture on drug loading and release are discussed. The kinetics of drug release from mesoporous silica systems is examined and the manufacturability and stability of these formulations are reviewed. Finally, the future prospects of mesoporous silica drug delivery systems are considered. Substantial progress has been made in the characterization and development of mesoporous drug delivery systems for drug dissolution enhancement. However, more research is required to fully understand the drug release kinetic profile from mesoporous silica materials. Incomplete drug release from the carrier and the possibility of drug re-adsorption onto the silica surface need to be investigated. Issues to be addressed include the manufacturability and regulation status of formulation approaches employing mesoporous silica to enhance drug dissolution. While more research is needed to support the move of this technology from the bench to a commercial medicinal product, it is a realistic prospect for the near future.

  3. 软模法磁性有序介孔炭的合成与表征%Synthesis and characterization of magnetic ordered mesoporous carbon materials using soft templating method

    王加; 林汉森; 王秀芳

    2012-01-01

    Magnetic ordered mesoporous carbon is synthesized through soft templating method by using triblock-copolymer Pluronic F127 as soft template,resorcinol-formaldehyde (RF) as carbon precursor and ferric nitrate as an iron source. HC1 is used as the catalyst for RF polymerization. The resultant materials are characterized by X-ray diffraction, N2 sorption and vibrating-sample magnetometer measurements. The results show that magnetic ordered mesoporous carbons are obtained when the Fe/R ratio is 0. 025. For those with Fe/R ratios greater than this value,the ordering,the BET surface area,pore volume and pore size decrease. N2 sorption isotherms of all the samples show representative type IV curves with HI hysteresis loops, which indicates a typical mesoporous material. Magnetic hysteresis loops show that the remanent magnetization of Fe/OMC samples increases with the increase of the content of Fe. This research can provide scientific proof for the optimized synthesis and application in magnetic separation for magnetic ordered mesoporous carbons.%以三嵌段共聚物为软模,间苯二酚-甲醛为炭前躯体,硝酸铁为铁源合成了磁性有序介孔炭,用XRD、氮气吸附、磁性测试等方法对样品进行表征.结果表明,当硝酸铁与间苯二酚摩尔比为0.025、0.05及0.10时得到的介孔炭具有有序性,随着铁质量分数的增加,有序性降低,比表面积、孔容都相应减小.基本磁化曲线结果表明,随着铁质量分数的增加,饱和磁化强度随之增加(0.01~0.10 emu/g),材料具有较好的磁性,容易从溶液中分离,表现出良好的分离性能.为磁性有序介孔炭的优化合成及磁性分离应用提供科学依据.

  4. 21 CFR 876.5600 - Sorbent regenerated dialysate delivery system for hemodialysis.

    2010-04-01

    ... dialyzer. The device is used with the extracorporeal blood system and the dialyzer of the hemodialysis... dialysate conditions. The sorbent cartridge may include absorbent, ion exchange and catalytic materials. (b...

  5. Mesoporous Transition Metal Oxides for Supercapacitors.

    Wang, Yan; Guo, Jin; Wang, Tingfeng; Shao, Junfeng; Wang, Dong; Yang, Ying-Wei

    2015-10-14

    Recently, transition metal oxides, such as ruthenium oxide (RuO₂), manganese dioxide (MnO₂), nickel oxides (NiO) and cobalt oxide (Co₃O₄), have been widely investigated as electrode materials for pseudo-capacitors. In particular, these metal oxides with mesoporous structures have become very hot nanomaterials in the field of supercapacitors owing to their large specific surface areas and suitable pore size distributions. The high specific capacities of these mesoporous metal oxides are resulted from the effective contacts between electrode materials and electrolytes as well as fast transportation of ions and electrons in the bulk of electrode and at the interface of electrode and electrolyte. During the past decade, many achievements on mesoporous transition metal oxides have been made. In this mini-review, we select several typical nanomaterials, such as RuO₂, MnO₂, NiO, Co₃O₄ and nickel cobaltite (NiCo₂O₄), and briefly summarize the recent research progress of these mesoporous transition metal oxides-based electrodes in the field of supercapacitors.

  6. Mesoporous Transition Metal Oxides for Supercapacitors

    Wang, Yan; Guo, Jin; Wang, Tingfeng; Shao, Junfeng; Wang, Dong; Yang, Ying-Wei

    2015-01-01

    Recently, transition metal oxides, such as ruthenium oxide (RuO2), manganese dioxide (MnO2), nickel oxides (NiO) and cobalt oxide (Co3O4), have been widely investigated as electrode materials for pseudo-capacitors. In particular, these metal oxides with mesoporous structures have become very hot nanomaterials in the field of supercapacitors owing to their large specific surface areas and suitable pore size distributions. The high specific capacities of these mesoporous metal oxides are resulted from the effective contacts between electrode materials and electrolytes as well as fast transportation of ions and electrons in the bulk of electrode and at the interface of electrode and electrolyte. During the past decade, many achievements on mesoporous transition metal oxides have been made. In this mini-review, we select several typical nanomaterials, such as RuO2, MnO2, NiO, Co3O4 and nickel cobaltite (NiCo2O4), and briefly summarize the recent research progress of these mesoporous transition metal oxides-based electrodes in the field of supercapacitors. PMID:28347088

  7. Mesoporous Transition Metal Oxides for Supercapacitors

    Yan Wang

    2015-10-01

    Full Text Available Recently, transition metal oxides, such as ruthenium oxide (RuO2, manganese dioxide (MnO2, nickel oxides (NiO and cobalt oxide (Co3O4, have been widely investigated as electrode materials for pseudo-capacitors. In particular, these metal oxides with mesoporous structures have become very hot nanomaterials in the field of supercapacitors owing to their large specific surface areas and suitable pore size distributions. The high specific capacities of these mesoporous metal oxides are resulted from the effective contacts between electrode materials and electrolytes as well as fast transportation of ions and electrons in the bulk of electrode and at the interface of electrode and electrolyte. During the past decade, many achievements on mesoporous transition metal oxides have been made. In this mini-review, we select several typical nanomaterials, such as RuO2, MnO2, NiO, Co3O4 and nickel cobaltite (NiCo2O4, and briefly summarize the recent research progress of these mesoporous transition metal oxides-based electrodes in the field of supercapacitors.

  8. Biocompatibility of Soft-Templated Mesoporous Carbons

    Gencoglu, Maria F. [Michigan Technological Univ., Houghton, MI (United States). Dept. of Chemical Engineering; Spurri, Amanda [Widener Univ., Chester, PA (United States). Dept. of Chemical Engineering; Franko, Mitchell [Widener Univ., Chester, PA (United States). Dept. of Chemical Engineering; Chen, Jihua [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS); Hensley, Dale K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS); Heldt, Caryn L. [Michigan Technological Univ., Houghton, MI (United States). Dept. of Chemical Engineering; Saha, Dipendu [Widener Univ., Chester, PA (United States). Dept. of Chemical Engineering

    2014-08-21

    We report that soft-templated mesoporous carbon is morphologically a non-nano type of carbon. It is a relatively newer variety of biomaterial, which has already demonstrated its successful role in drug delivery applications. To investigate the toxicity and biocompatibility, we introduced three types of mesoporous carbons with varying synthesis conditions and pore textural properties. We compared the Brunauer–Emmett–Teller (BET) surface area and pore width and performed cytotoxicity experiments with HeLa cells, cell viability studies with fibroblast cells and hemocomapatibility studies. Cytotoxicity tests reveal that two of the carbons are not cytotoxic, with cell survival over 90%. The mesoporous carbon with the highest surface area showed slight toxicity (~70% cell survival) at the highest carbon concentration of 500 μg/mL. Fibroblast cell viability assays suggested high and constant viability of over 98% after 3 days with no apparent relation with materials property and good visible cell-carbon compatibility. No hemolysis (<1%) was confirmed for all the carbon materials. Protein adsorption experiments with bovine serum albumin (BSA) and fibrinogen revealed a lower protein binding capacity of 0.2–0.6 mg/m2 and 2–4 mg/m2 for BSA and fibrinogen, respectively, with lower binding associated with an increase in surface area. The results of this study confirm the biocompatibility of soft-templated mesoporous carbons.

  9. Sorbents based on xerogels of zirconium, aluminum and manganese oxyhydroxides

    R.V. Smotraiev

    2016-05-01

    Full Text Available The actual problem of water supply in the world and in Ukraine, in particular, is a high level of pollution in water resources and an insufficient level of drinking water purification. With industrial wastewater, a significant amount of pollutants falls into water bodies, including suspended particles, sulfates, iron compounds, heavy metals, etc. Aim: The aim of this work is to determine the impact of aluminum and manganese ions additives on surface and sorption properties of zirconium oxyhydroxide based sorbents during their production process. Materials and Methods: The sorbents based on xerogels of zirconium, aluminum and manganese oxyhydroxides were prepared by sol-gel method during the hydrolysis of metal chlorides (zirconium oxychloride ZrOCl2, aluminum chloride AlCl3 and manganese chloride MnCl2 with carbamide. Results: The surface and sorption properties of sorbents based on xerogels of zirconium, aluminum and manganese oxyhydroxides were investigated. X-ray amorphous structure and evolved hydroxyl-hydrate cover mainly characterize the obtained xerogels. The composite sorbents based on xerogels of zirconium oxyhydroxide doped with aluminum oxyhydroxide (aS = 537 m2/g and manganese oxyhydroxide (aS = 356 m2/g have more developed specific surface area than single-component xerogels of zirconium oxyhydroxide (aS = 236 m2/g and aluminum oxyhydroxide (aS = 327 m2/g. The sorbent based on the xerogel of zirconium and manganese oxyhydroxides have the maximum SO42--ions sorption capacity. It absorbs 1.5 times more SO42–-ions than the industrial anion exchanger AN-221. The sorbents based on xerogels of zirconium oxyhydroxide has the sorption capacity of Fe3+-ions that is 1.5…2 times greater than the capacity of the industrial cation exchanger KU-2-8. The Na+-ions absorption capacity is 1.47…1.56 mmol/g for each sorbent. Conclusions: Based on these data it can be concluded that the proposed method is effective for sorbents production based on

  10. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    David A. Green; Brian S. Turk; Raghubir Gupta; Alejandro Lopez-Ortiz

    2001-01-01

    Four grades of sodium bicarbonate and two grades of trona were characterized in terms of particle size distribution, surface area, pore size distribution, and attrition. Surface area and pore size distribution determinations were conducted after calcination of the materials. The sorbent materials were subjected to thermogravimetric testing to determine comparative rates and extent of calcination (in inert gas) and sorption (in a simulated coal combustion flue gas mixture). Selected materials were exposed to five calcination/sorption cycles and showed no decrease in either sorption capacity or sorption rate. Process simulations were conducted involving different heat recovery schemes. The process is thermodynamically feasible. The sodium-based materials appear to have suitable physical properties for use as regenerable sorbents and, based on thermogravimetric testing, are likely to have sorption and calcination rates that are rapid enough to be of interest in full-scale carbon sequestration processes.

  11. Textural Properties of Hybrid Biomedical Materials Made from Extracts of Tournefortia hirsutissima L. Imbibed and Deposited on Mesoporous and Microporous Materials

    Miguel Ángel Hernández

    2016-01-01

    Full Text Available Our research group has developed a group of hybrid biomedical materials potentially useful in the healing of diabetic foot ulcerations. The organic part of this type of hybrid materials consists of nanometric deposits, proceeding from the Mexican medicinal plant Tournefortia hirsutissima L., while the inorganic part is composed of a zeolite mixture that includes LTA, ZSM-5, clinoptilolite, and montmorillonite (PZX as well as a composite material, made of CaCO3 and montmorillonite (NABE. The organic part has been analyzed by GC-MS to detect the most abundant components present therein. In turn, the inorganic supports were characterized by XRD, SEM, and High Resolution Adsorption (HRADS of N2 at 76 K. Through this latter methodology, the external surface area of the hybrid materials was evaluated; besides, the most representative textural properties of each substrate such as total pore volume, pore size distribution, and, in some cases, the volume of micropores were calculated. The formation and stabilization of nanodeposits on the inorganic segments of the hybrid supports led to a partial blockage of the microporosity of the LTA and ZSM5 zeolites; this same effect occurred with the NABE and PZX substrates.

  12. Functionalized bimodal mesoporous silicas as carriers for controlled aspirin delivery

    Gao Lin; Sun Jihong; Li Yuzhen

    2011-01-01

    The bimodal mesoporous silica modified with 3-aminopropyltriethoxysilane was performed as the aspirin carrier. The samples' structure, drug loading and release profiles were characterized with X-ray diffraction, scanning electron microscopy, N 2 adsorption and desorption, Fourier transform infrared spectroscopy, TG analysis, elemental analysis and UV-spectrophotometer. For further exploring the effects of the bimodal mesopores on the drug delivery behavior, the unimodal mesoporous material MCM-41 was also modified as the aspirin carrier. Meantime, Korsmeyer-Peppas equation f t =kt n was employed to analyze the dissolution data in details. It is indicated that the bimodal mesopores are beneficial for unrestricted drug molecules diffusing and therefore lead to a higher loading and faster releasing than that of MCM-41. The results show that the aspirin delivery properties are influenced considerably by the mesoporous matrix, whereas the large pore of bimodal mesoporous silica is the key point for the improved controlled-release properties. - Graphical abstract: Loading (A) and release profiles (B) of aspirin in N-BMMs and N-MCM-41 indicated that BMMs have more drug loading capacity and faster release rate than that MCM-41. Highlights: → Bimodal mesoporous silicas (BMMs) and MCM-41 modified with amino group via post-treatment procedure. → Loading and release profiles of aspirin in modified BMMs and MCM-41. → Modified BMMs have more drug loading capacity and faster release rate than that modified MCM-41.

  13. An organosilane-directed growth-induced etching strategy for preparing hollow/yolk–shell mesoporous organosilica nanospheres with perpendicular mesochannels and amphiphilic frameworks

    Zou, Houbing

    2014-06-27

    We have developed an organosilane-directed growth-induced etching strategy to prepare hollow periodic mesoporous organosilica (PMO) nanospheres with perpendicular mesoporous channels and a clear hollow interior as well as an amphiphilic framework. This facile strategy is simple, efficient, and highly controllable. Silica nanospheres were utilized as hard templates to obtain hollow PMO nanospheres through a one-step route, with the structure parameter highly controlled by adjusting the synthesis conditions. Different organosilanes were used to obtain bridged hollow PMO nanospheres of different organic groups and showed different directed capacities. The integrity of the bridged organic group was confirmed by Fourier-transform infrared (FT-IR) spectroscopy and solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Transmission electron microscopy (TEM) observations showed that the growth of the PMO shell and the dissolution of the silica nanosphere core occurred simultaneously for each nanosphere, while 29Si NMR spectra revealed that the dissolved silica species from the silica nanospheres transformed into PMO shells by co-condensation with hydrolyzed organosilane oligomers. As a result, the obtained hollow nanospheres were amphiphilic, which can even be used as a particle emulsifier for O-W or W-O emulsion in various systems. These materials can also be served as an efficient sorbent for removal of hydrophobic contaminants in water. Using the proposed formation mechanism, this strategy can be extended to transform silica-coated composite materials into yolk-shell structures with a functional interior core and a perpendicular mesoporous amphiphilic shell. As a nanoreactor, the -Ph- bridged amphiphilic shell showed a faster diffusion rate for organic reactants in water than the hydrophilic silica shell, and thus better catalytic activity for reduction of 4-nitrophenol. This journal is © the Partner Organisations 2014.

  14. Primary secondary amine as a sorbent material in dispersive solid-phase extraction clean-up for the determination of indicator polychlorinated biphenyls in environmental water samples by gas chromatography with electron capture detection.

    Guo, Yuanming; Hu, Hongmei; Li, Tiejun; Xue, Lijian; Zhang, Xiaoning; Zhong, Zhi; Zhang, Yurong; Jin, Yanjian

    2017-08-01

    A simple, rapid, and novel method has been developed and validated for determination of seven indicator polychlorinated biphenyls in water samples by gas chromatography with electron capture detection. 1 L of water samples containing 30 g of anhydrous sodium sulfate was first liquid-liquid extracted with an automated Jipad-6XB vertical oscillator using n-hexane/dichloromethane (1:1, v/v). The concentrated extract was cleaned up by dispersive solid-phase extraction with 100 mg of primary secondary amine as sorbent material. The linearity of this method ranged from 1.25 to 100 μg/L, with regression coefficients ranging between 0.9994 and 0.9999. The limits of detection were in the ng/L level, ranging between 0.2 and 0.3 ng/L. The recoveries of seven spiked polychlorinated biphenyls with external calibration method at different concentration levels in tap water, lake water, and sea water were in the ranges of 85-112, 76-116, and 72-108%, respectively, and with relative standard deviations of 3.3-4.5, 3.4-5.6, and 3.1-4.8% (n = 5), respectively. The performance of the proposed method was compared with traditional liquid-liquid extraction and solid-phase extraction clean-up methods, and comparable efficiencies were obtained. It is concluded that this method can be successfully applied for the determination of polychlorinated biphenyls in different water samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. High capacity carbon dioxide sorbent

    Dietz, Steven Dean; Alptekin, Gokhan; Jayaraman, Ambalavanan

    2015-09-01

    The present invention provides a sorbent for the removal of carbon dioxide from gas streams, comprising: a CO.sub.2 capacity of at least 9 weight percent when measured at 22.degree. C. and 1 atmosphere; an H.sub.2O capacity of at most 15 weight percent when measured at 25.degree. C. and 1 atmosphere; and an isosteric heat of adsorption of from 5 to 8.5 kilocalories per mole of CO.sub.2. The invention also provides a carbon sorbent in a powder, a granular or a pellet form for the removal of carbon dioxide from gas streams, comprising: a carbon content of at least 90 weight percent; a nitrogen content of at least 1 weight percent; an oxygen content of at most 3 weight percent; a BET surface area from 50 to 2600 m.sup.2/g; and a DFT micropore volume from 0.04 to 0.8 cc/g.

  16. Decontamination formulation with sorbent additive

    Tucker; Mark D. , Comstock; Robert H.

    2007-10-16

    A decontamination formulation and method of making that neutralizes the adverse health effects of both chemical and biological compounds, especially chemical warfare (CW) and biological warfare (BW) agents, and toxic industrial chemicals. The formulation provides solubilizing compounds that serve to effectively render the chemical and biological compounds, particularly CW and BW compounds, susceptible to attack, and at least one reactive compound that serves to attack (and detoxify or kill) the compound. The formulation includes at least one solubilizing agent, a reactive compound, a bleaching activator, a sorbent additive, and water. The highly adsorbent, water-soluble sorbent additive (e.g., sorbitol or mannitol) is used to "dry out" one or more liquid ingredients, such as the liquid bleaching activator (e.g., propylene glycol diacetate or glycerol diacetate) and convert the activator into a dry, free-flowing powder that has an extended shelf life, and is more convenient to handle and mix in the field.

  17. Technology assessment guide for application of engineered sorbent barriers to low-level radioactive waste disposal sites

    Freeman, H.D.; Jones, E.O.; Depner, J.P.

    1989-06-01

    An engineered sorbent barrier (ESB) uses sorbent materials (such as activated carbon or natural zeolites) to restrict migration of radionuclides from low-level waste sites. The permeability of the ESB allows moisture to pass while the sorbent material traps or absorbs contaminants. In contrast, waste sites with impermeable barriers could fill with water, especially those waste sites in humid climates. A sorbent barrier can be a simple, effective, and inexpensive method for restricting radionuclide migration. This report provides information and references to be used in assessing the sorbent barrier technology for low-level waste disposal. The ESB assessment is based on sorbent material and soil properties, site conditions, and waste properties and inventories. These data are used to estimate the thickness of the barrier needed to meet all performance requirements for the waste site. This document addresses the following areas: (1) site information required to assess the need and overall performance of a sorbent barrier; (2) selection and testing of sorbent materials and underlying soils; (3) use of radionuclide transport models to estimate the required barrier thickness and long-term performance under a variety of site conditions; (4) general considerations for construction and quality assurance; and (5) cost estimates for applying the barrier. 37 refs., 6 figs., 2 tabs.

  18. Recent progress in electrocatalysts with mesoporous structures for application in polymer electrolyte membrane fuel cells

    Xing, Wei; Wu, Zucheng; Tao, Shanwen

    2016-01-01

    Recently mesoporous materials have drawn great attention in fuel cell related applications, such as preparation of polymer electrolyte membranes and catalysts, hydrogen storage and purification. In this mini-review, we focus on recent developments in mesoporous electrocatalysts for polymer electrolyte membrane fuel cells, including metallic and metal-free catalysts for use as either anode or cathode catalysts. Mesoporous Pt-based metals have been synthesized as anode catalysts with improved a...

  19. Synthesis of mesoporous silica microsphere from dual surfactant

    Venkatathri Narayanan

    2008-12-01

    Full Text Available A new procedure is reported to synthesis mesoporous silica micro sphere for the first time. In these method two surfactants namely Span 80 and Tween 80 were used. Small angle X ray diffraction and N2 adsorption analysis shows the synthesized material has mesoporous property. The material has spherical morphology with 1-10 µm particle size. Beside the material found to have microcapsule property as observed from the Transmission electron microscopy. The Fourier transform Infrared spectroscopic analysis reveals that the materials are similar to other mesoporous materials. We also encapsulated an UV-absorber Ibuprofen inside the microcapsule, by mixing it before the synthesis. This shows a possibility of the materials in cosmetic applications.

  20. Drug Loading of Mesoporous Silicon

    Moffitt, Anne; Coffer, Jeff; Wang, Mengjia

    2011-03-01

    The nanostructuring of crystalline solids with low aqueous solubilities by their incorporation into mesoporous host materials is one route to improve the bioavailability of such solids. Earlier studies suggest that mesoporous Si (PSi), with pore widths in the range of 5-50 nm, is a candidate for such an approach. In this presentation, we describe efforts to load curcumin into free-standing microparticles of PSi. Curcumin is a compound extracted from turmeric root, which is an ingredient of curry. Curucmin has shown activity against selected cancer cell lines, bacteria, and other medical conditions. However, curcumin has a very low bioavailability due to its extremely low water solubility (0.6 μ g/mL). Incorporation of curcumin was achieved by straightforward loading of the molten solid at 185circ; C. Loading experiments were performed using PSi particles of two different size ranges, 45-75 μ m and 150-250 μ m. Longer loading times and ratio of curcumin to PSi leads to a higher percentage of loaded curcumin in both PSi particle sizes (as determined by weight difference). The extent of curcumin crystallinity was assessed by x-ray diffraction (XRD). The solubility and release kinetics of loaded curcumin from the PSi was determined by extraction into water at 37circ; C, with analysis using UV-VIS spectrometry. NSF-REU and TCU.

  1. Carbon-Containing Waste of Coal Enterprises in Magnetic Sorbents Technology

    Kvashevaya, Ekaterina; Ushakova, Elena; Ushakov, Andrey

    2017-11-01

    The article shows the issues state of coal-mining enterprises carbonaceous wastes utilization, including by obtaining oil-sorbent. The characteristics of the feedstock are presented; experiment methods of obtaining a binder based on the livestock enterprises waste, of forming binder with filler (sawdust, coal waste); of pyrogenetic processing to obtain a sorbent are described. Possible options for the introduction of magnetite (a magnetic component) in the composition of the oil sorbent are considered: on the surface, in the volume of the granule and the magnetite core. In the course of the work it was found that the optimum content of coal dust in the sorbent granules is 75% by weight, and the most effective way of obtaining the magnetic sorbent is to apply the carbon material directly to the "core" of magnetite. However, in this case, the problem of finding an effective binder for magnetite arises. The option of applying magnetite on the surface of a carbon sorbent is not effective. Thus, at present, we use a mixture of coal waste, which binds to the uniform distribution of magnetite in the volume. The developed magnetic sorbents can be used in various weather conditions, including strong winds and icing of water bodies, as well as for small and medium currents.

  2. Mesoporous Zeolite Single Crystals for Catalytic Hydrocarbon Conversion

    Schmidt, I.; Christensen, Claus H.; Kustova, Marina

    2005-01-01

    Recently, mesoporous zeolite single crystals were discovered. They constitute a novel family of materials that features a combined micropore and mesopore architecture within each individual crystal. Here, we briefly summarize recent catalytic results from cracking and isomerization of alkalies......, alkylation of aromatics and present new results on isomerization of aromatics. Specifically, the shape-selective isomerization of meta-xylenc into para-xylene and ortho-xylene is studied. In all these reactions, rnesoporous zeolite single crystals prove to be unique catalysts since they provide easy...... transport to and from active sites and at the same time maintain the shape-selectivity required. Thus, all these results support the idea that the beneficial effect of the mesopores system in the mesoporous zeolite single crystals call be solely attributed to enhanced mass transport....

  3. Aluminum-rich mesoporous MFI - type zeolite single crystals

    Kustova, Marina; Kustov, Arkadii; Christensen, Christina Hviid

    2005-01-01

    Zeolitcs are crystalline materials, which are widely used as solid acid catalysts and supports in many industrial processes. Recently, mesoporous MFI-type zeolite single crystals were synthesized by use of carbon particles as a mesopore template and sodium aluminate as the aluminum Source....... With this technique, only zeolites with relatively low Al contents were reported (Si/Al ratio about 100). In this work, the preparation of aluminum-rich mesoporous MFI-type zeolite single crystals (Si/Al similar to 16-50) using aluminum isopropoxide as the aluminum Source is reported for the first time. All samples...... are characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), ammonia temperature programmed desorption (NH3-TPD), and N-2 adsorption measurements. The obtained zeolites combine the high crystallinity and the characteristic micropores of zeolites with an intracrystalline mesopore system...

  4. In Situ Growth of Mesoporous Silica with Drugs on Titanium Surface and Its Biomedical Applications.

    Wan, Mimi; Zhang, Jin; Wang, Qi; Zhan, Shuyue; Chen, Xudong; Mao, Chun; Liu, Yuhong; Shen, Jian

    2017-06-07

    Mesoporous silica has been developed for the modification of titanium surfaces that are used as implant materials. Yet, the traditional modification methods failed to effectively construct mesoporous silica on the titanium surface evenly and firmly, in which the interaction between mesoporous silica and titanium was mainly physical. Here, in situ growth of mesoporous silica on a titanium surface was performed using a simple evaporation-induced self-assembly strategy. Meantime, in situ introduction of drugs (heparin and vancomycin) to mesoporous silica was also adopted to improve the drug-loading amount. Both the above-mentioned processes were completed at the same time. Transmission electron microscopy, N 2 adsorption-desorption isotherms, Fourier transform infrared spectroscopy, scanning electron microscopy, and water contact angle measurements were used to characterize the structure of the mesoporous silica film. Results indicated that the mesoporous silica film that in situ grew on the titanium surface was smooth, thin, transparent, and stable. Cytotoxicity, proliferation performance of osteoblast cells, and in vitro and in vivo studies of the antibacterial activity of the coating were tested. This is the first study to modify the titanium surface by the in situ growth of a mesoporous silica coating with two kinds of drugs. The stability of the mesoporous silica coating can be attributed to the chemical bonding between dopamine and silicon hydroxyl of the mesoporous silica coating, and the smooth surface of mesoporous silica is a result of the method of in situ growth. The large amount of drug-loading also could be ascribed to the in situ introduction of drugs during the synthetic process. The strategy proposed in this work will bring more possibilities for the preparation of advanced functional materials based on the combination of mesoporous structure and metallic materials.

  5. Lime-Based Sorbents for High-Temperature CO2 Capture—A Review of Sorbent Modification Methods

    Manovic, Vasilije; Anthony, Edward J.

    2010-01-01

    This paper presents a review of the research on CO2 capture by lime-based looping cycles undertaken at CanmetENERGY’s (Ottawa, Canada) research laboratories. This is a new and very promising technology that may help in mitigation of global warming and climate change caused primarily by the use of fossil fuels. The intensity of the anticipated changes urgently requires solutions such as more cost-effective technologies for CO2 capture. This new technology is based on the use of lime-based sorbents in a dual fluidized bed combustion (FBC) reactor which contains a carbonator—a unit for CO2 capture, and a calciner—a unit for CaO regeneration. However, even though natural materials are cheap and abundant and very good candidates as solid CO2 carriers, their performance in a practical system still shows significant limitations. These limitations include rapid loss of activity during the capture cycles, which is a result of sintering, attrition, and consequent elutriation from FBC reactors. Therefore, research on sorbent performance is critical and this paper reviews some of the promising ways to overcome these shortcomings. It is shown that reactivation by steam/water, thermal pre-treatment, and doping simultaneously with sorbent reforming and pelletization are promising potential solutions to reduce the loss of activity of these sorbents over multiple cycles of use. PMID:20948952

  6. Lime-Based Sorbents for High-Temperature CO2 Capture—A Review of Sorbent Modification Methods

    Edward J. Anthony

    2010-08-01

    Full Text Available This paper presents a review of the research on CO2 capture by lime-based looping cycles undertaken at CanmetENERGY’s (Ottawa, Canada research laboratories. This is a new and very promising technology that may help in mitigation of global warming and climate change caused primarily by the use of fossil fuels. The intensity of the anticipated changes urgently requires solutions such as more cost-effective technologies for CO2 capture. This new technology is based on the use of lime-based sorbents in a dual fluidized bed combustion (FBC reactor which contains a carbonator—a unit for CO2 capture, and a calciner—a unit for CaO regeneration. However, even though natural materials are cheap and abundant and very good candidates as solid CO2 carriers, their performance in a practical system still shows significant limitations. These limitations include rapid loss of activity during the capture cycles, which is a result of sintering, attrition, and consequent elutriation from FBC reactors. Therefore, research on sorbent performance is critical and this paper reviews some of the promising ways to overcome these shortcomings. It is shown that reactivation by steam/water, thermal pre-treatment, and doping simultaneously with sorbent reforming and pelletization are promising potential solutions to reduce the loss of activity of these sorbents over multiple cycles of use.

  7. Ultrasound-driven design of new mesoporous metal catalysts

    Schaeferhans, Jana; Pazos Perez, Nicolas; Andreeva, Daria [Physikalische Chemie II, Univ. Bayreuth (Germany); Skorb, Ekaterina [Max-Planck-Institut fuer Kolloid- und Grenzflaechenforschung, Golm (Germany)

    2011-07-01

    Mesoporous metal nanocomposites were formed by a ''green chemistry'' method with ultrasound irradiation. The sonication technique combines the fabrication of a mesoporous support consisting of metallic particles (Al, Mg) several tens of micrometers in size and the subsequent incorporation of metal (Ag, Au, Pt etc.) nanoparticles into its pores. Next to filling the mesoporous support with particles we are also able to form mesoporous alloys e.g. AlNi or CoAlFe. The resulting material is analyzed by transmission electron microscopy, powder X-ray diffraction, small-angle neutron scattering and the Brunauer-Emmett-Teller and the Barrett-Joyner-Halenda method. Surface areas up to 200 m{sup 2}/g with a narrow pore size distribution around 3 nm can be achieved. The mesoporous structures are analyzed by confocal light microscopy after coloring the particles with dye. We explain the formation of the mesoporous inner structures by the following mechanism: Thermal etching and recrystallization of metals by ultrasound-stimulated high-speed jets of liquid form the porous structure that is stabilized by surface oxidation through free radicals generated during cavitation. We expect this approach to be universal and opening perspectives for a whole new class of catalytic materials that can be prepared in a fairly easy and cost effective way.

  8. Theoretical Predictions of the thermodynamic Properties of Solid Sorbents Capture CO2 Applications

    Duan, Yuhua; Sorescu, Dan; Luebke David; Pennline, Henry

    2012-05-02

    We are establishing a theoretical procedure to identify most potential candidates of CO{sub 2} solid sorbents from a large solid material databank to meet the DOE programmatic goal for energy conversion; and to explore the optimal working conditions for the promising CO{sub 2} solid sorbents, especially from room to warm T ranges with optimal energy usage, used for both pre- and post-combustion capture technologies.

  9. Application of clay minerals from Cayo Guan, Cuba, as sorbents of heavy metals and ceramic raw materials; Aplicaciones de los minerales arcillosos de Cayo Guan, Cuba, como adsorbentes de metales pesados y materia prima ceramica

    Fonseca, D.; Barba, F.; Callejas, P.; Recio, P.

    2012-11-01

    It has been studied by Analysis Heating Microscope Optical the behaviour of some kaolinitic clays from a reservoir of Cayo Guan rich in iron oxides and low silica content proving to be a refractory materials whose softening appears after 1500 degree centigrade. It has obtained the workability diagram of the different clay minerals calculating the plasticity by the method of Casagrande spoon; only one of the samples is in the area suitable for extrusion. Vitrification diagrams report that the capacity of water absorption is <0.6 % when the temperature of 1400 degree centigrade is achieved. We have designed a program to calculate compositions of porcelain stoneware prepared from these modified clays adding low-cost raw materials that facilitate the formation of glassy phase ((potassium feldspar and glass cullet) and/or increase the silica (sand and diatomaceous earth used as filters in the brewing industry). With one of these compositions, prepared in the laboratory (60 % of clay, 30 % feldspar and 10 % of diatomaceous earth), calcined at 1250 degree centigrade with a heating rate of 15 degree centigrade/min, the results were: water absorption 0.8 %, and linear shrinkage 21 % without any deformation observed. These clays have been treated with acid to eliminate its high iron content and study its application as an sorbent of heavy metals as Cd{sup 2}+, Cr{sup 3}+. The results of the immobilization of these elements have been compared with those obtained with thermally activated vermiculite at 800 degree centigrade, showing that the treated samples show sorption of both cadmium and chromium below the vermiculite, but the non-treated ones are suitable to remove chromium; this is because these clays do not contain in its composition exchangeable ions (Ca{sup {sub 2}} +, Mg{sup 2} +, Na{sup +}, K{sup +}), and even if they are chemically activated only the presence of Fe ions is which produces form bindings (Cr{sub x}.Fe{sub 1}-x) (OH){sub 3} which favor Cr sorption

  10. Qualification of the ALKASORB sorbent for the sorption-enhanced water-gas shift process

    Van Selow, E.R.; Cobden, P.D.; Dijk, Van H.A.J.; Walspurger, S.; Verbraeken, P.A.; Jansen, D.

    2013-07-01

    For the sorption-enhanced water-gas shift (SEWGS) process, a new sorbent material has been qualified in a reactor of 2 m length under conditions close to industrial designs. The sorbent ALKASORB is a potassium-carbonate promoted hydrotalcite-based compound. ALKASORB is shown to have many favourable properties in comparison to the reference sorbent, in particular with respect to mechanical stability. The cyclic capacity of the new compound is substantially higher than the cyclic capacity of the reference sorbent, and it allows a reduction of the steam requirement of 50%. The sorbent has demonstrated catalytic activity for the water-gas shift reaction that is sufficient to omit a separate catalyst. It is demonstrated that the sorbent remains chemically and mechanically stable during operation of at least 2000 adsorption-desorption cycles, even in the presence of H2S in the feed. H2S is shown not to influence CO2 adsorption capacity and is co-captured with the CO2. In contrast to the reference material that showed mechanical degradation during extended adsorption-desorption cycles, the new material is stable and allows to obtain carbon capture levels exceeding 95% more efficiently and more economically since the required size of the vessels will be smaller.

  11. Modeling of boldine alkaloid adsorption onto pure and propyl-sulfonic acid-modified mesoporous silicas. A comparative study

    Geszke-Moritz, Małgorzata, E-mail: Malgorzata.Geszke-Moritz@amu.edu.pl [NanoBioMedical Centre, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Moritz, Michał, E-mail: michal.moritz@put.poznan.pl [Poznan University of Technology, Faculty of Chemical Technology, Institute of Chemistry and Technical Electrochemistry, Berdychowo 4, 60-965 Poznań (Poland)

    2016-12-01

    The present study deals with the adsorption of boldine onto pure and propyl-sulfonic acid-functionalized SBA-15, SBA-16 and mesocellular foam (MCF) materials. Siliceous adsorbents were characterized by nitrogen sorption analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier-transform infrared (FT-IR) spectroscopy and thermogravimetric analysis. The equilibrium adsorption data were analyzed using the Langmuir, Freundlich, Redlich-Peterson, and Temkin isotherms. Moreover, the Dubinin-Radushkevich and Dubinin-Astakhov isotherm models based on the Polanyi adsorption potential were employed. The latter was calculated using two alternative formulas including solubility-normalized (S-model) and empirical C-model. In order to find the best-fit isotherm, both linear regression and nonlinear fitting analysis were carried out. The Dubinin-Astakhov (S-model) isotherm revealed the best fit to the experimental points for adsorption of boldine onto pure mesoporous materials using both linear and nonlinear fitting analysis. Meanwhile, the process of boldine sorption onto modified silicas was described the best by the Langmuir and Temkin isotherms using linear regression and nonlinear fitting analysis, respectively. The values of adsorption energy (below 8 kJ/mol) indicate the physical nature of boldine adsorption onto unmodified silicas whereas the ionic interactions seem to be the main force of alkaloid adsorption onto functionalized sorbents (energy of adsorption above 8 kJ/mol). - Graphical abstract: Modeling of boldine adsorption onto unmodified and propyl-sulfonic acid-modified mesoporous adsorbents. - Highlights: • The process of boldine adsorption onto SBA-15, SBA-16 and MCF silicas was examined. • Siliceous adsorbents were functionalized with propyl-sulfonic acid groups. • The equilibrium adsorption data were analyzed using several isotherm models. • Both linear regression and nonlinear fitting analysis were carried out.

  12. Investigation of mesoporous structures for thermoelectric applications

    Cojocaru, A.; Carstensen, J.; Foell, H.; Boor, J.; Schmidt, V.

    2011-01-01

    Mesoporous silicon is an attractive material for thermoelectric application. For pore wall thicknesses around <100 nm, phonons can not penetrate the porous layer while electrons still can, due to there smaller mean free path length. The resulting good electrical and bad thermal conductivity is a premise for efficient thermoelectric devices. This paper presents results regarding homogeneity, high porosity, and optimal pore wall thicknesses for porous silicon based thermoelectric devices.

  13. Acylation Reactions over Zeolites and Mesoporous Catalysts

    Voláková, Martina; Vitvarová, Dana; Čejka, Jiří

    2009-01-01

    Roč. 2, č. 6 (2009), s. 486-499 ISSN 1864-5631 R&D Projects: GA ČR GA104/07/0383; GA ČR GD203/08/H032; GA MPO FT-TA5/005 Institutional research plan: CEZ:AV0Z40400503 Keywords : acylation * ketones * mesoporous materials * shape-selectivity * zeolites Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.767, year: 2009

  14. Sorbent Nanotechnologies for Water Cleaning

    Ahmed, Snober

    Despite decades of regulatory efforts to mitigate water pollution, many chemicals, particularly heavy metals, still present risks to human health. In addition to direct exposure, certain metals such as mercury threaten public health due to its persistence, bioaccumulation and bioamplification throughout the food chain. A number of U.S. Federal and State regulations have been established to reduce the levels of mercury in water. Activated carbon (AC) has been widely explored for the removal of mercury. However, AC suffers from many limitations inherent to its chemical properties, and it becomes increasingly challenging to meet current and future regulations by simply modifying AC to enhance its performance. Recently, the performance of nanosorbents have been studied in order to removal pollutants. Nanosorbents utilize the ultra-high reactive surface of nanoparticles for rapid, effective and even permanent sequestration of heavy metals from water and air, thus showed promising results as compared to AC. The goal of this thesis research is to develop nanomaterial-based sorbents for the removal of mercury from water. It describes the development of a new solid-support assisted growth of selenium nanoparticles, their use for water remediation, and the development of a new nanoselenium-based sorbent sponge for fast and efficient mercury removal. The nanoselenium sorbent not only shows irreversible interaction with mercury but also exhibits remarkable properties by overcoming the limitations of AC. The nanoselenium sponge was shown to remove mercury to undetectable levels within one minute. This new sponge technology would have an impact on inspiring new stringent regulations and lowering costs to help industries meet regulatory requirements, which will ultimately help improve air and water quality, aquatic life and public health.

  15. Sorbent Structural Impacts Due to Humidity on Carbon Dioxide Removal Sorbents for Advanced Exploration Systems

    Watson, David; Knox, James C.; West, Phillip; Stanley, Christine M.; Bush, Richard

    2015-01-01

    The Life Support Systems Project (LSSP) under the Advanced Exploration Systems (AES) program builds upon the work performed under the AES Atmosphere Resource Recovery and Environmental Monitoring (ARREM) project focusing on the numerous technology development areas. The CO2 removal and associated air drying development efforts are focused on improving the current state-of-the-art system on the International Space Station (ISS) utilizing fixed beds of sorbent pellets by seeking more robust pelletized sorbents, evaluating structured sorbents, and examining alternate bed configurations to improve system efficiency and reliability. A component of the CO2 removal effort encompasses structural stability testing of existing and emerging sorbents. Testing will be performed on dry sorbents and sorbents that have been conditioned to three humidity levels. This paper describes the sorbent structural stability screening efforts in support of the LSS Project within the AES Program.

  16. Multifunctional EuYVO4 nanoparticles coated with mesoporous silica

    Justino, Larissa G.; Nigoghossian, Karina; Capote, Ticiana S.O.; Scarel-Caminaga, Raquel M.; Ribeiro, Sidney J.L.; Caiut, José Maurício A.

    2016-01-01

    Mesoporous structures are interesting materials for the incorporation of dyes, drugs, and luminescent systems, leading to materials with important multifunctionalities. In a very unique way, these guest/host materials combine the high stability of inorganic systems, new guest-structuring features, and adsorption mechanisms in their well-defined pores. This work evaluates the luminescent properties of rare earth-doped YVO 4 nanoparticles coated with a mesoporous silica shell. The use of two different synthesis methodologies allowed for particle size control. The crystalline phase emerged without further heat treatment. The mesoporous shell decreased undesirable quenching effects on YVO 4 :Eu 3+ nanoparticles and rendered them biocompatible. The materials prepared herein could have interesting applications as luminescent markers or drug release systems.

  17. Surface modification to improve the sorption property of U(VI) on mesoporous silica

    Lijuan Song; Yulong Wang; Lu Zhu; Bolong Guo; Suwen Chen; Wangsuo Wu

    2014-01-01

    Polyoxometalates K 7 [α-PW 11 O 39 ]·14H 2 O (PW11) modified mesoporous silica (MCM-48) with cubic structure, was prepared by impregnation and calcination methods. The modified mesoporous silica sorbent (PW11/MCM-48) was studied as a potential adsorbent for U(VI) from aqueous solutions. MCM-48 and PW11/MCM-48 were confirmed by X-ray diffraction and nitrogen physisorption techniques. The results indicate the original keggin structure of PW11 and mesoporous structure of MCM-48 are maintained after supporting PW11 on mesoporous silica MCM-48. The effects of contact time, solid-to-liquid ratio (m/V), solution pH and ionic strength on U(VI) sorption behaviors of the pure and modified mesoporous silicas were also studied. Typical sorption isotherms such as Langmuir and Freundlich isotherms were determined for sorption process. The results suggest that the sorption of U(VI) on MCM-48 or PW11/MCM-48 are strongly dependent on pH values but independent of ionic strength. The sorption capacity of PW11/MCM-48 for U(VI) is about ten times more than that of MCM-48. (author)

  18. Sorbents for waste water purification from radionuclides and other toxic substances

    Maddalone, R.F.; MakKlenason, L.Ts.

    1996-01-01

    The TRW firm (USA) developed the system for sorption and disposal of radionuclides, heavy metals and organic substances, based on utilization of carbon sorbents. The sorbent is produced through processing natural coal by alkali-salt solution and has a large specific pores surface (up to 1000 m 2 /g). The sorbent carboxyl ionogenic groups are able of absorbing heavy metals cations from waste waters. Sorption by uranium constituted 30 mg/l. The sorbent with absorbed substances may be burnt (it contains no sulfur) or delivered for vitrification. The volume of disposed materials constitutes in comparison with existing techniques for uranium isotopes 420000 : 1. The costs are reduced up to 0.26 doll/m 2 of reprocessed water. 2 refs., 2 figs., 4 tabs

  19. Application of fibrous complexing sorbents for trace elements preconcentration and separation

    Zakhartchenko, E.A.; Myasoedova, G.V.

    2003-01-01

    This article demonstrates the application of the 'filled' fibrous sorbents for preconcentration and separation of platinum metals, as well as heavy metals and radionuclides. The POLYORGS complexing sorbents and ion-exchangers were used as fillers. Dynamic preconcentration conditions should be set for complete sorption of the elements: diameter and mass of the sorbent disk or the column as well as flow rate of the solution. These conditions depend on specific features of materials to be analysed and the requirements of the experimental task or detection method. Extensive alteration of features as well as perfect kinetic properties and high selectivity of the 'filled' sorbents confirm their applicability for trace elements preconcentration and separation in technology and analytical chemistry. (authors)

  20. Zinc-oxide-based sorbents and processes for preparing and using same

    Gangwal, Santosh Kumar; Turk, Brian Scott; Gupta, Raghubir Prasael

    2010-03-23

    Zinc oxide-based sorbents, and processes for preparing and using them are provided. The sorbents are preferably used to remove one or more reduced sulfur species from gas streams. The sorbents comprise an active zinc component, optionally in combination with one or more promoter components and/or one or more substantially inert components. The active zinc component is a two phase material, consisting essentially of a zinc oxide (ZnO) phase and a zinc aluminate (ZnAl.sub.2O.sub.4) phase. Each of the two phases is characterized by a relatively small crystallite size of typically less than about 500 Angstroms. Preferably the sorbents are prepared by converting a precursor mixture, comprising a precipitated zinc oxide precursor and a precipitated aluminum oxide precursor, to the two-phase, active zinc oxide containing component.

  1. Vapor phase versus liquid phase grafting of meso-porous alumina

    Sripathi, V.G.P.; Mojet, Barbara; Nijmeijer, Arian; Benes, Nieck Edwin

    2013-01-01

    Functionalization of meso-porous c-alumina has been performed by grafting of 3-Aminopropyltrimethoxysilane (3APTMS) simultaneously from either the liquid phase or from the vapor phase. In both cases, after grafting nitrogen physisorption indicates that the materials remain meso-porous with

  2. Hierarchically Porous Carbon Materials for CO 2 Capture: The Role of Pore Structure

    Estevez, Luis [Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, United States; Barpaga, Dushyant [Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, United States; Zheng, Jian [Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, United States; Sabale, Sandip [Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, United States; Patel, Rajankumar L. [Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, United States; Zhang, Ji-Guang [Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, United States; McGrail, B. Peter [Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, United States; Motkuri, Radha Kishan [Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, United States

    2018-01-17

    With advances in porous carbon synthesis techniques, hierarchically porous carbon (HPC) materials are being utilized as relatively new porous carbon sorbents for CO2 capture applications. These HPC materials were used as a platform to prepare samples with differing textural properties and morphologies to elucidate structure-property relationships. It was found that high microporous content, rather than overall surface area was of primary importance for predicting good CO2 capture performance. Two HPC materials were analyzed, each with near identical high surface area (~2700 m2/g) and colossally high pore volume (~10 cm3/g), but with different microporous content and pore size distributions, which led to dramatically different CO2 capture performance. Overall, large pore volumes obtained from distinct mesopores were found to significantly impact adsorption performance. From these results, an optimized HPC material was synthesized that achieved a high CO2 capacity of ~3.7 mmol/g at 25°C and 1 bar.

  3. Mesoporous Silica Molecular Sieve based Nanocarriers: Transpiring Drug Dissolution Research.

    Pattnaik, Satyanarayan; Pathak, Kamla

    2017-01-01

    Improvement of oral bioavailability through enhancement of dissolution for poorly soluble drugs has been a very promising approach. Recently, mesoporous silica based molecular sieves have demonstrated excellent properties to enhance the dissolution velocity of poorly water-soluble drugs. Current research in this area is focused on investigating the factors influencing the drug release from these carriers, the kinetics of drug release and manufacturing approaches to scale-up production for commercial manufacture. This comprehensive review provides an overview of different methods adopted for synthesis of mesoporous materials, influence of processing factors on properties of these materials and drug loading methods. The drug release kinetics from mesoporous silica systems, the manufacturability and stability of these formulations are reviewed. Finally, the safety and biocompatibility issues related to these silica based materials are discussed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  4. Application of engineered sorbent barriers Summary of Laboratory Data for FY 1988

    Freeman, H.D.; Jones, E.O.

    1989-09-01

    Laboratory studies were conducted in FY 1988 Pacific Northwest Laboratory to determine the effect of contact time, pH, solution to solid ratio, and particle size on the performance of a number of materials in adsorbing radioactive cobalt, strontium, and cesium. The laboratory studies were conducted to provide background information useful in designing an engineered sorbent barrier, which restricts the migration of radionuclides from low-level waste sites. Understanding how the variables affect the adsorption of ions on the sorbent materials is the key to estimating the performance of sorbent barriers under a variety of conditions. The scope of the studies was limited to three radionuclides and four sorbent materials, but the general approach can be used to evaluate other radionuclides and conditions. The sorbent materials evaluated in this study included clinoptilolite, activated carbon, bentonite clay, and Savannah River soil. The clinoptilolite and activated carbon were identified in previous studies as the most cost-effective materials for sorption of the three radionuclides under consideration. The bentonite clay was evaluated as a component of the barrier that could be used to modify the permeability of the barrier system. The Savannah River soil was used to represent soil from a humid site. 3 refs., 14 figs., 1 tab.

  5. Sorbents for effective removal of radioactive antimony during chemical decontamination

    Nishad, Padala Abdul; Bhaskarapillai, Anupkumar; Velmurugan, Sankaralingam

    2014-01-01

    Removal of radioactive antimony is a challenging problem. Often, during decontamination, they get mobilized around the system and redeposit in different areas thus offsetting the reduction in the radiation field obtained by removing other activities such as 60 Co. Thus, there is a clear need for better antimony removing materials/strategies for effective reactor decontamination. In this regard, six commercially available sorbents namely, Tulsion A33 (strong base anion (-OH) resin), Amberlite IRC-718 (chelating resin), Radex ® Sb-1000, nano TiO 2 -special grade (Inorganic type IX), Chitosan (biosorbent) and Aeroxide p25 (nano TiO 2 , Inorganic type IX) were evaluated for their antimony sorption properties. Radex ® and TiO 2 based materials were found to be more effective in removing both Sb(V) and Sb(III). Solution pH was seen to significantly influence the antimony sorption and the effect was more prominent in anion resin, when tested under column conditions. Apart from the commercial sorbents, we have synthesised a robust high performing sorbent (TA-Chitosan beads) in the form of stable beads, using nano-TiO 2 and chitosan. The beads were found to retain the antimony sorption properties of the nano-TiO 2 , while adapting a physical format suitable for large scale operations. The sorbent exhibited almost complete sorption of antimony both in low (ppb level) as well as high concentrations of antimony. The suitability of the beads for use in column mode has been established and its radiation stability was probed in detail. The beads were found to be stable to irradiations as ascertained from the TOC values and unchanged sorption properties. The sorption properties of the CHITA beads in typical decontamination formulation containing mixture of complexing agents have been investigated in detail. (author)

  6. Hierarchical Mesoporous Lithium-Rich Li[Li0.2Ni0.2Mn0.6]O2 Cathode Material Synthesized via Ice Templating for Lithium-Ion Battery.

    Li, Yu; Wu, Chuan; Bai, Ying; Liu, Lu; Wang, Hui; Wu, Feng; Zhang, Na; Zou, Yufeng

    2016-07-27

    Tuning hierarchical micro/nanostructure of electrode materials is a sought-after means to reinforce their electrochemical performance in the energy storage field. Herein, we introduce a type of hierarchical mesoporous Li[Li0.2Ni0.2Mn0.6]O2 microsphere composed of nanoparticles synthesized via an ice templating combined coprecipitation strategy. It is a low-cost, eco-friendly, and easily operated method using ice as a template to control material with homogeneous morphology and rich porous channels. The as-prepared material exhibits remarkably enhanced electrochemical performances with higher capacity, more excellent cycling stability and more superior rate property, compared with the sample prepared by conventional coprecipitation method. It has satisfactory initial discharge capacities of 280.1 mAh g(-1) at 0.1 C, 207.1 mAh g(-1) at 2 C, and 152.4 mAh g(-1) at 5 C, as well as good cycle performance. The enhanced electrochemical performance can be ascribed to the stable hierarchical microsized structure and the improved lithium-ion diffusion kinetics from the highly porous structure.

  7. Sorbents for the oxidation and removal of mercur

    Olson, Edwin S.; Holmes, Michael J.; Pavlish, John Henry

    2017-09-12

    A promoted activated carbon sorbent is described that is highly effective for the removal of mercury from flue gas streams. The sorbent comprises a new modified carbon form containing reactive forms of halogen and halides. Optional components may be added to increase reactivity and mercury capacity. These may be added directly with the sorbent, or to the flue gas to enhance sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The sorbent can be regenerated and reused. Sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active sorbent into the mercury contaminated gas stream are described.

  8. Sorbents for the oxidation and removal of mercury

    Olson, Edwin S [Grand Forks, ND; Holmes, Michael J [Thompson, ND; Pavlish, John H [East Grand Forks, MN

    2008-10-14

    A promoted activated carbon sorbent is described that is highly effective for the removal of mercury from flue gas streams. The sorbent comprises a new modified carbon form containing reactive forms of halogen and halides. Optional components may be added to increase reactivity and mercury capacity. These may be added directly with the sorbent, or to the flue gas to enhance sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The sorbent can be regenerated and reused. Sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active sorbent into the mercury contaminated gas stream are described.

  9. Sorbents for the oxidation and removal of mercury

    Olson, Edwin S [Grand Forks, ND; Holmes, Michael J [Thompson, ND; Pavlish, John H [East Grand Forks, MN

    2012-05-01

    A promoted activated carbon sorbent is described that is highly effective for the removal of mercury from flue gas streams. The sorbent comprises a new modified carbon form containing reactive forms of halogen and halides. Optional components may be added to increase reactivity and mercury capacity. These may be added directly with the sorbent, or to the flue gas to enhance sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The sorbent can be regenerated and reused. Sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active sorbent into the mercury contaminated gas stream are described.

  10. Amine-modified ordered mesoporous silica: The effect of pore size on CO{sub 2} capture performance

    Wang, Lin; Yao, Manli [Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004 (China); Hu, Xin [College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004 (China); Hu, Gengshen, E-mail: gshu@zjnu.edu.cn [Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004 (China); Lu, Jiqing; Luo, Mengfei [Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004 (China); Fan, Maohong, E-mail: mfan@uwyo.edu [Department of Chemical and Petroleum Engineering, University of Wyoming, Laramie, WY 82071 (United States)

    2015-01-01

    Highlights: • Larger pore size could decrease the mass transfer resistance and increase the interaction between CO{sub 2} and TEPA. • The CO{sub 2} uptakes of sorbents were enhanced in the presence of moisture. • The sorbents are stable and regenerable under test conditions. - Abstract: The objective of current research is to investigate the effect of pore size of mesoporous silica supports on the CO{sub 2} capture performance of solid amine sorbents. Two ordered mesoporous silicas (OMS) with different pore sizes (5.6 nm and 7.6 nm) were synthesized as tetraethylenepentamine (TEPA) supports. A serious of techniques, such as physical adsorption, infrared spectroscopy and thermal gravimetric analysis were used to characterize the solid amine sorbents. The CO{sub 2} capture performances of the sorbents were evaluated using breakthrough method with a fixed-bed reactor equipped with an online mass spectrometer. The experimental results indicate that the pore size has significant influence on CO{sub 2} capture performance. Larger pore size could decrease the mass transfer resistance and increase the interaction between CO{sub 2} and TEPA. Therefore, OMS-7.6 is better than OMS-5.6 as amine support. The highest CO{sub 2} sorption capacities achieved with OMS-7.6 with 50 wt% TEPA loading (OMS-7.6-50) in the absence and presence of moisture are 3.45 mmol/g and 4.28 mmol/g, respectively, under the conditions of 10.0% CO{sub 2}/N{sub 2} mixture at 75 °C. Cyclic CO{sub 2} adsorption–desorption experiments indicate that the solid amine sorbents are fairly stable and regenerable.

  11. Sorption of short-lived radionuclides in a layer of sorbent with spherical granules

    Karlin, Yu.V.

    1993-01-01

    Sorption methods have found wide application in the purification of liquid radioactive wastes. The working element in sorption methods for this purpose is usually a sorption column with a fixed layer of sorbent. Continuous-action equipment with a moving layer of sorbent is very seldom used. When a fixed layer of sorbent is used its wear and prolonged mixing in the sorption column are reduced to a minimum, and maximum purification is achieved due to the advantages of the dynamic method of sorption over the static method. The time of protective action of the sorbent layer is determined by the time taken for the radionuclide to pass through the sorption column, and for the majority of radionuclides is determined by numerous parameters, including the type of sorbent and radionuclide, the rate of flow through the sorbent, the size of the sorbent granules, etc. The physical and chemical aspects of this process have been investigated in detail, and numerous methods for modeling it mathematically have been developed and have been used to develop methods of designing sorption column apparatus. The specific nature of the radionuclides as unstable materials enables the hypothetical case of a open-quotes perpetualclose quotes sorption filter to be represented. In fact, to achieve this it is only necessary to assume that the half-life of the radionuclide is so small that the rate of decay of the radionuclide in the sorption column (both in the sorbed state and in the aqueous phase of the sorption layer) is equal to the rate that it is fed into the column in the flow of liquid radioactive waste. In this case the sorption front of the radionuclide in the column wall remains fixed after a certain initial period. In this paper, a mathematical model of such a hypothetical filter for the case of spherical sorbent granules is considered

  12. Reactivity improvement of Ca(OH)2 sorbent using diatomaceous earth (DE) from Aceh Province

    Mariana, M.; Mahidin, M.; Mulana, F.; Agam, T.; Hafdiansyah, F.

    2018-04-01

    In this study, the diatomaceous earth (DE) from Aceh Province was used to increase the reactivity of Ca(OH)2sorbent. The high silica (SiO2) content of about 97% in the diatomaceous earth allows the increasing reactivity of Ca(OH)2sorbent by forming calcium silicate hydrate (CSH). The CSH improved the porosity characteristic of the sorbent. The improvement process was performed by mixing Ca(OH)2sorbent, diatomaceous earth and water in a beaker glass at the Ca(OH)2/DE weight ratio of 1:10 for 2 hand then dried at 120 °C for 24 h. The dried sorbent was calcined at 500 °C and 800 °C for 2 h. The activated sorbent was characterized using Scanning Electron Microscopy (SEM) for the morphological properties; X- Ray Diffraction (XRD) for the materials characteristics. The adsorption capacity of thesorbent was tested by methylene blue adsorption. The results showed that the Ca(OH)2/DEsorbent had a higher porosity than the Ca(OH)2 adsorbent.The results also showed that Ca(OH)2/DE which was calcined at higher temperature of 800 °C had a higher adsorption capacity compared to Ca(OH)2/DE which was calcined at lower temperature of 500 °C.

  13. Activation and characterization of waste coffee grounds as bio-sorbent

    Mariana; Marwan; Mulana, F.; Yunardi; Ismail, T. A.; Hafdiansyah, M. F.

    2018-03-01

    As the city well known for its culture of coffee drinkers, modern and traditional coffee shops are found everywhere in Banda Aceh, Indonesia. High number of coffee shops in the city generates large quantities of spent coffee grounds as waste without any effort to convert them as other valuable products. In an attempt to reduce environmental problems caused by used coffee grounds, this research was conducted to utilize waste coffee grounds as an activated carbon bio-sorbent. The specific purpose of this research is to improve the performance of coffee grounds bio-sorbent through chemical and physical activation, and to characterize the produced bio-sorbent. Following physical activation by carbonization, a chemical activation was achieved by soaking the carbonized waste coffee grounds in HCl solvent and carbonization process. The activated bio-sorbent was characterized for its morphological properties using Scanning Electron Microscopy (SEM), its functional groups by Fourier Transform Infra-Red Spectrophotometer (FTIR), and its material characteristics using X-Ray Diffraction (XRD). Characterization of the activated carbon prepared from waste coffee grounds shows that it meets standard quality requirement in accordance with Indonesian National Standard, SNI 06-3730-1995. Activation process has modified the functional groups of the waste coffee grounds. Comparing to natural waste coffee grounds, the resulted bio-sorbent demonstrated a more porous surface morphology following activation process. Consequently, such bio-sorbent is a potential source to be used as an adsorbent for various applications.

  14. Sorption of methylxanthines by different sorbents

    Dmitrienko, S. G.; Andreeva, E. Yu.; Tolmacheva, V. V.; Terent'eva, E. A.

    2013-05-01

    Sorption of caffeine, theophylline, theobromine, diprophylline, and pentoxyphylline on different sorbents (supercross-linked polystyrene, surface-modified copolymer of styrene and divinylbenzene Strata-X, and carbon nanomaterials Taunit and Diasorb-100-C16T) was studied in a static mode in an effort to find new sorbents suitable for sorption isolation and concentration of methylxanthines. The peculiarities of sorption of methylxanthines were explained in relation to the solution acidity, the nature of the sorbates and their concentration, the nature of the solvent, and the structural characteristics of the sorbents.

  15. Catalytic properties of Thallium-containing mesoporous silicas

    A. Baradji

    2017-02-01

    Full Text Available The benzylation of benzene by benzyl chloride over a series of Thallium-containing mesoporous silicas with different Tl contents has been investigated. These materials (Tl-HMS-n have been characterized by chemical analysis, N2 adsorption/desorption isotherm and X-ray diffraction (XRD. The mesoporous Thallium-containing materials showed both high activity and high selectivity for the benzylation of benzene. More interesting is the observation that these catalysts are always active and selective for large molecules like naphthenic compounds such as methoxynaphthalene.

  16. Bulk Concentration Dependence of Electrolyte Resistance Within Mesopores of Carbon Electrodes in Electric Double-Layer Capacitors

    Kim, Jaekwang; Kim, Daeun; Lee, Ilbok; Son, Hyungbin; Lee, Donghyun; Yoon, Songhun [Chung-Ang University, Seoul (Korea, Republic of); Shim, Hyewon [Korea Institute of Nuclear Nonproliferation and Control, Daejeon (Korea, Republic of); Lee, Jinwoo [POSTECH, Pohang (Korea, Republic of)

    2016-02-15

    Hexagonally ordered mesoporous carbon materials were prepared and used as electrode materials in an electric double-layer capacitor. Using this electrode, the change of electrolyte resistance within the mesopores was investigated according to the bulk electrolyte concentration. Using three different electrochemical transient experiments-imaginary capacitance analysis, chronoamperometry, and hronopotentiometry-the time constant associated with electrolyte transport was determined, which was then used to obtain the electrolyte resistance within the mesopores. With decreasing electrolyte concentration, the increase in electrolyte resistance was smaller than the increase in the resistivity of the bulk electrolyte, which is indicative of a different environment for ionic transport within the mesopores. On using the confinement effect within the mesopores, the predicted higher concentration within mesopore probably results in lower electrolyte resistance, especially under low bulk concentrations.

  17. Mesoporous Prussian blue analogues: template-free synthesis and sodium-ion battery applications.

    Yue, Yanfeng; Binder, Andrew J; Guo, Bingkun; Zhang, Zhiyong; Qiao, Zhen-An; Tian, Chengcheng; Dai, Sheng

    2014-03-17

    The synthesis of mesoporous Prussian blue analogues through a template-free methodology and the application of these mesoporous materials as high-performance cathode materials in sodium-ion batteries is presented. Crystalline mesostructures were produced through a synergistically coupled nanocrystal formation and aggregation mechanism. As cathodes for sodium-ion batteries, the Prussian blue analogues all show a reversible capacity of 65 mA h g-1 at low current rate and show excellent cycle stability. The reported method stands as an environmentally friendly and low-cost alternative to hard or soft templating for the fabrication of mesoporous materials.

  18. Mesoporous titanium phosphate molecular sieves with ion-exchange capacity.

    Bhaumik, A; Inagaki, S

    2001-01-31

    Novel open framework molecular sieves, titanium(IV) phosphates named, i.e., TCM-7 and -8 (Toyota Composite Materials, numbers 7 and 8), with new mesoporous cationic framework topologies obtained by using both cationic and anionic surfactants are reported. The (31)P MAS NMR, UV-visible absorption, and XANES data suggest the tetrahedral state of P and Ti, and stabilization of the tetrahedral state of Ti in TCM-7/8 is due to the incorporation of phosphorus (at Ti/P = 1:1) vis-à-vis the most stable octahedral state of Ti in the pure mesoporous TiO(2). Mesoporous TCM-7 and -8 show anion exchange capacity due to the framework phosphonium cation and cation exchange capacity due to defective P-OH groups. The high catalytic activity in the liquid-phase partial oxidation of cyclohexene with a dilute H(2)O(2) oxidant supports the tetrahedral coordination of Ti in these materials.

  19. Near-field radiative heat transfer in mesoporous alumina

    Li Jing; Feng Yan-Hui; Zhang Xin-Xin; Huang Cong-Liang; Wang Ge

    2015-01-01

    The thermal conductivity of mesoporous material has aroused the great interest of scholars due to its wide applications such as insulation, catalyst, etc. Mesoporous alumina substrate consists of uniformly distributed, unconnected cylindrical pores. Near-field radiative heat transfer cannot be ignored, when the diameters of the pores are less than the characteristic wavelength of thermal radiation. In this paper, near-field radiation across a cylindrical pore is simulated by employing the fluctuation dissipation theorem and Green function. Such factors as the diameter of the pore, and the temperature of the material are further analyzed. The research results show that the radiative heat transfer on a mesoscale is 2∼4 orders higher than on a macroscale. The heat flux and equivalent thermal conductivity of radiation across a cylindrical pore decrease exponentially with pore diameter increasing, while increase with temperature increasing. The calculated equivalent thermal conductivity of radiation is further developed to modify the thermal conductivity of the mesoporous alumina. The combined thermal conductivity of the mesoporous alumina is obtained by using porosity weighted dilute medium and compared with the measurement. The combined thermal conductivity of mesoporous silica decreases gradually with pore diameter increasing, while increases smoothly with temperature increasing, which is in good agreement with the experimental data. The larger the porosity, the more significant the near-field effect is, which cannot be ignored. (paper)

  20. Mesoporous Silica from Rice Husk Ash

    S.A. Mandavgane

    2010-12-01

    Full Text Available Mesoporous silica is used as a raw material in several areas: in preparation of catalysts, in inks, as aconcrete hardening accelerator, as a component of detergents and soaps, as a refractory constituent etc.Sodium silicate is produced by reacting rice hull ash (RHA with aqueous NaOH and silica is precipitatedfrom the sodium silicate by acidification. In the present work, conversion of about 90% of silica containedin RHA into sodium silicate was achieved in an open system at temperatures of about 100 °C. The resultsshowed that silica obtained from RHA is mesoporous, has a large surface area and small particle size.Rice Husk is usually mixed with coal and this mixture is used for firing boilers. The RHA therefore, usuallycontains carbon particles. Activated carbon embedded on silica has been prepared using the carbon alreadypresent in RHA. This carbon shows good adsorption capacity. ©2010 BCREC UNDIP. All rights reserved(Received: 25th April 2010, Revised: 17th June 2010, Accepted: 24th June 2010[How to Cite: V.R. Shelke, S.S. Bhagade, S.A. Mandavgane. (2010. Mesoporous Silica from Rice Husk Ash. Bulletin of Chemical Reaction Engineering and Catalysis, 5 (2: 63-67. doi:10.9767/bcrec.5.2.793.63-67

  1. Mesoporous Silica from Rice Husk Ash

    V.R. Shelke

    2011-01-01

    Full Text Available Mesoporous silica is used as a raw material in several areas: in preparation of catalysts, in inks, as a concrete hardening accelerator, as a component of detergents and soaps, as a refractory constituent etc. Sodium silicate is produced by reacting rice hull ash (RHA with aqueous NaOH and silica is precipitated from the sodium silicate by acidification. In the present work, conversion of about 90% of silica contained in RHA into sodium silicate was achieved in an open system at temperatures of about 100 °C. The results showed that silica obtained from RHA is mesoporous, has a large surface area and small particle size. Rice Husk is usually mixed with coal and this mixture is used for firing boilers. The RHA therefore, usually contains carbon particles. Activated carbon embedded on silica has been prepared using the carbon already present in RHA. This carbon shows good adsorption capacity. ©2010 BCREC UNDIP. All rights reserved(Received: 25th April 2010, Revised: 17th June 2010, Accepted: 24th June 2010[How to Cite: V.R. Shelke, S.S. Bhagade, S.A. Mandavgane. (2010. Mesoporous Silica from Rice Husk Ash. Bulletin of Chemical Reaction Engineering and Catalysis, 5 (2: 63-67. doi:10.9767/bcrec.5.2.793.63-67][DOI: http://dx.doi.org/10.9767/bcrec.5.2.793.63-67

  2. Mesoporous metal catalysts formed by ultrasound

    Schaeferhans, Jana; Pazos Perez, Nicolas; Andreeva, Daria [Physikalische Chemie II, Universitaet Bayreuth (Germany)

    2010-07-01

    We study the ultrasound-driven formation of mesoporous metal sponges. The collapse of acoustic cavitations leads to very high temperatures and pressures on very short scales. Therefore, structures may be formed and quenched far from equilibrium. Mechanism of metal modification by ultrasound is complex and involves a variety of aspects. We propose that modification of metal particles and formation of mesoporous inner structures can be achieved due to thermal etching of metals by ultrasound stimulated high speed jets of liquid. Simultaneously, oxidation of metal surfaces by free radicals produced in water during cavitation stabilizes developed metal structures. Duration and intensity of the ultrasonication treatment is able to control the structure and morphology of metal sponges. We expect that this approach to the formation of nanoscale composite sponges is universal and opens perspective for a whole new class of catalytic materials that can be prepared in a one-step process. The developed method makes it possible to control the sponge morphology and can be used for formation of modern types of catalysts. For example, the sonication technique allows to combine the fabrication of mesoporous support and distribution of metal (Cu, Pd, Au, Pt etc.) nanoparticles in its pores into a single step.

  3. Enhanced capture of elemental mercury by bamboo-based sorbents

    Tan, Zengqiang [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Xiang, Jun, E-mail: xiangjun@mail.hust.edu.cn [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Su, Sheng, E-mail: susheng_sklcc@hotmail.com [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Zeng, Hancai; Zhou, Changsong; Sun, Lushi; Hu, Song; Qiu, Jianrong [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer The KI-modified BC has excellent capacity for elemental mercury removal. Black-Right-Pointing-Pointer The chemisorption plays a dominant role for the modified BC materials. Black-Right-Pointing-Pointer The BC-I has strong anti-poisoning ability with the presence of NO or SO{sub 2}. - Abstract: To develop cost-effective sorbent for gas-phase elemental mercury removal, the bamboo charcoal (BC) produced from renewable bamboo and KI modified BC (BC-I) were used for elemental mercury removal. The effect of NO, SO{sub 2} on gas-phase Hg{sup 0} adsorption by KI modified BC was evaluated on a fixed bed reactor using an online mercury analyzer. BET surface area analysis, temperature programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS) were used to determine the pore structure and surface chemistry of the sorbents. The results show that KI impregnation reduced the sorbents' BET surface area and total pore volume compared with that of the original BC. But the BC-I has excellent adsorption capacity for elemental mercury at a relatively higher temperature of 140 Degree-Sign C and 180 Degree-Sign C. The presence of NO or SO{sub 2} could inhibit Hg{sup 0} capture, but BC-I has strong anti-poisoning ability. The specific reaction mechanism has been further analyzed.

  4. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    David A. Green; Brian S. Turk; Raghubir P. Gupta; Alejandro Lopez-Ortiz; Douglas P. Harrison; Ya Liang

    2001-07-01

    Sodium based sorbents including sodium carbonate may be used to capture carbon dioxide from flue gas. A relatively concentrated carbon dioxide stream may be recoverable for sequestration when the sorbent is regenerated. Electrobalance tests indicated that sodium carbonate monohydrate was formed in a mixture of helium and water vapor at temperatures below 65 C. Additional compounds may also form, but this could not be confirmed. In the presence of carbon dioxide and water vapor, both the initial reaction rate of sodium carbonate with carbon dioxide and water and the sorbent capacity decreased with increasing temperature, consistent with the results from the previous quarter. Increasing the carbon dioxide concentration at constant temperature and water vapor concentration produced a measurable increase in rate, as did increasing the water vapor concentration at constant carbon dioxide concentration and temperature. Runs conducted with a flatter TGA pan resulted in a higher initial reaction rate, presumably due to improved gas-solid contact, but after a short time, there was no significant difference in the rates measured with the different pans. Analyses of kinetic data suggest that the surface of the sodium carbonate particles may be much hotter than the bulk gas due to the highly exothermic reaction with carbon dioxide and water, and that the rate of heat removal from the particle may control the reaction rate. A material and energy balance was developed for a cyclic carbonation/calcination process which captures about 26 percent of the carbon dioxide present in flue gas available at 250 C.

  5. Cleanup of Savannah River Plant solvent using solid sorbents

    Mailen, J.C.; Tallent, O.K.

    1985-04-01

    The degradation products produced in Purex solvent by exposure to nitric acid and radiation can be divided into two groups: those which are removed by scrubbing with sodium carbonate solutions and those which are not; these latter materials are called secondary degradation products. This study investigated the use of solid sorbents for removal of the secondary degradation products from first-cycle Savannah River Plant solvent that had been previously washed with sodium carbonate solution. Silica gel, activated charcoal, macroreticular resin, attapulgite clay and activated alumina were the sorbents investigated in preliminary testing. Activated alumina was found to be most effective for improving phase separation of the solvent from sodium carbonate solutions and for increasing the interfacial tension. The activated alumina was also the sorbent most useful for removing complexants which retain plutonium at low acidity, but it was less effective in removing anionic surfactants and ruthenium. We found that the capacity of the activated alumina was greatly improved by drying the solvent before treatment

  6. Low-Cost Sorbents: A Literature Summary

    Bailey, Susan

    1997-01-01

    The capital and regeneration costs of activated carbon and ion exchange media suggest that better process economics may be achieved with disposable sorbents for the treatment of metals-contaminated...

  7. Effect of silica/titania ratio on enhanced photooxidation of industrial hazardous materials by microwave treated mesoporous SBA-15/TiO{sub 2} nanocomposites

    Mehta, Akansha; Mishra, Amit; Sharma, Manisha; Singh, Satnam; Basu, Soumen, E-mail: soumen.basu@thapar.edu [Thapar University, School of Chemistry and Biochemistry (India)

    2016-07-15

    In this study microwave assisted technique has been adopted for the synthesis of different weight ratios of TiO{sub 2} dispersed on Santa barbara amorphous-15 (SBA-15) support. Morphological study revealed TiO{sub 2} particles (4–10 nm) uniformly distributed on SBA-15 while increases in SBA-15 content results in higher specific surface area (524–237 m{sup 2}/g). The diffraction intensity of 101 plane of anatase polymorph was seen increasing with increase in TiO{sub 2} ratio. All the photocatalysts were having a mesoporous nature and follow the Langmuir IV isotherm, SBA-15 posses the highest pore volume (0.93 cm{sup 3} g{sup −1}) which consistently decreased with TiO{sub 2} content and was lowest (0.50 cm{sup 3} g{sup −1}) in case of 5 wt% of TiO{sub 2} followed by P25 (0.45 cm{sup 3} g{sup −1}) while pore diameter increased after TiO{sub 2} incorporation due to pore strain. The photocatalytic activity of the nanocomposites were analysed for the photodegradation of alizarin dye and pentachlorophenol under UV light irradiation. The reaction kinetics suggested the highest efficiency (98 % for alizarin and 94 % for PCP) of 5 wt% TiO{sub 2} compared to other photocatalysts, these nanocomposites were reused for several cycles, which is most important for heterogeneous photocatalytic degradation reaction.Graphical abstractThis study demonstrates the synthesis of silica embedded TiO{sub 2} nanocomposites by microwave assisted technique and their catalytic influence on degradation of organic dyes and pollutants. Higher loading of titania (SBA-15/TiO{sub 2}, 1:5) results better catalytic performance than commercial nano TiO{sub 2} (P25).

  8. Rational design of mesoporous metals and related nanomaterials by a soft-template approach.

    Yamauchi, Yusuke; Kuroda, Kazuyuki

    2008-04-07

    We review recent developments in the preparation of mesoporous metals and related metal-based nanomaterials. Among the many types of mesoporous materials, mesoporous metals hold promise for a wide range of potential applications, such as in electronic devices, magnetic recording media, and metal catalysts, owing to their metallic frameworks. Mesoporous metals with highly ordered networks and narrow pore-size distributions have traditionally been produced by using mesoporous silica as a hard template. This method involves the formation of an original template followed by deposition of metals within the mesopores and subsequent removal of the template. Another synthetic method is the direct-template approach from lyotropic liquid crystals (LLCs) made of nonionic surfactants at high concentrations. Direct-template synthesis creates a novel avenue for the production of mesoporous metals as well as related metal-based nanomaterials. Many mesoporous metals have been prepared by the chemical or electrochemical reduction of metal salts dissolved in aqueous LLC domains. As a soft template, LLCs are more versatile and therefore more advantageous than hard templates. It is possible to produce various nanostructures (e.g., lamellar, 2D hexagonal (p6mm), and 3D cubic (Ia\\3d)), nanoparticles, and nanotubes simply by controlling the composition of the reaction bath.

  9. Hydrothermal synthesis of mesoporous metal oxide arrays with enhanced properties for electrochemical energy storage

    Xiao, Anguo; Zhou, Shibiao; Zuo, Chenggang; Zhuan, Yongbing; Ding, Xiang

    2015-01-01

    Highlights: • NiO mesoporous nanowall arrays are prepared via hydrothermal method. • Mesoporous nanowall arrays are favorable for fast ion/electron transfer. • NiO mesoporous nanowall arrays show good supercapacitor performance. - Abstract: Mesoporous nanowall NiO arrays are prepared by a facile hydrothermal synthesis method with a following annealing process. The NiO nanowall shows continuous mesopores ranging from 5 to 10 nm and grows vertically on the substrate forming a porous net-like structure with macropores of 20–300 nm. A plausible mechanism is proposed for the growth of mesoporous nanowall NiO arrays. As cathode material of pseudocapacitors, the as-prepared mesoporous nanowall NiO arrays show good pseudocapacitive performances with a high capacitance of 600 F g −1 at 2 A g −1 and impressive high-rate capability with a specific capacitance of 338 F g −1 at 40 A g −1 . In addition, the mesoporous nanowall NiO arrays possess good cycling stability. After 6000 cycles at 2 A g −1 , a high capacitance of 660 F g −1 is attained, and no obvious degradation is observed. The good electrochemical performance is attributed to its highly porous morphology, which provides large reaction surface and short ion diffusion paths, leading to enhanced electrochemical properties

  10. Mesoporous carbon prepared from carbohydrate as hard template for hierarchical zeolites

    Egeblad, Kresten; Christensen, Claus H.

    2007-01-01

    treatment of a mixture of sucrose and ammonia followed by carbonization of the mixture in N-2 at high temperatures. The porous carbon produced by this method was subsequently applied as a hard template in the synthesis of mesoporous silicalite-1 and removed by combustion after synthesis. X-ray diffraction......A mesoporous carbon prepared from sucrose was successfully employed as a hard template to produce hierarchical silicalite-1, thus providing a very simple and inexpensive route to desirable zeolite catalysts from widely available raw materials. The porous carbon was prepared by hydrothermal...... the porous carbon template as well as the mesoporous zeolite single-crystal material....

  11. The spectroscopic study of building composites containing natural sorbents.

    Król, M; Mozgawa, W

    2011-08-15

    This work presents the results of FT-IR spectroscopic studies of heavy metal cations (Ag(+), Pb(2+), Zn(2+), Cd(2+) and Cr(3+)) immobilization from aqueous solutions on natural sorbents. The sorption has been conducted on sodium forms of zeolite (clinoptilolite) and clay minerals (mixtures containing mainly montmorillonite and kaolinite) which have been separated from natural Polish deposit. In the next part of the work both sorbents were used to obtain new building composites. It was proven those heavy metal cations' sorption causes changes in IR spectra of the zeolite and clay minerals. These alterations are dependent on the way the cations were sorbed. In the case of zeolite, variations of the bands corresponding to the characteristic ring vibrations have been observed. These rings occur in pseudomolecular complexes 4-4-1 (built of alumino- and silicooxygen tetrahedra) which constitute the secondary building units (SBU) and form spatial framework of the zeolite. The most significant changes have been determined in the region of pseudolattice vibrations (650-700 cm(-1)). In the instance of clay minerals, changes in the spectra occur at two ranges: 1200-800 cm(-1)--the range of the bands assigned to asymmetric Si-O(Si,Al) and bending Al-OH vibrations and 3800-3000 cm(-1)--the range of the bands originating from OH(-) groups stretching vibrations. Next results indicate possibilities of applying the used natural sorbents for the obtainment of new building materials having favourable composition and valuable properties. The zeolite was used for obtaining autoclaved materials with an addition of CaO, and the clay minerals for ceramic sintered materials with an addition of quartz and clinoptilolite were produced. FT-IR studies were also conducted on the obtained materials. Copyright © 2010 Elsevier B.V. All rights reserved.

  12. Large pore bi-functionalised mesoporous silica for metal ion pollution treatment

    Burke, Aoife M.; Hanrahan, John P.; Healy, David A.; Sodeau, John R.; Holmes, Justin D.; Morris, Michael A.

    2009-01-01

    Here we demonstrate aminopropyl and mercatopropyl functionalised and bi-functionalised large pore mesoporous silica spheres to extract various metal ions from aqueous solutions towards providing active sorbents for mitigation of metal ion pollution. Elemental analysis (EA) and FTIR techniques were used to quantify the attachment of the aminopropyl and mercatopropyl functional groups to the mesoporous silica pore wall. Functionalisation was achieved by post-synthesis reflux procedures. For all functionalised silicas the functionalisation refluxing does not alter particle morphology/agglomeration of the particles. It was found that sorptive capacities of the mesoporous silica towards the functional groups were unaffected by co-functionalisation. Powder X-ray diffraction (PXRD) and nitrogen adsorption techniques were used to establish the pore diameters, packing of the pores and specific surface areas of the modified mesoporous silica spheres. Atomic absorption (AA) spectroscopy and inductively coupled plasma-atomic emission spectrometry (ICP-AES) techniques were used to measure the extraction efficiencies of each metal ion species from solution at varying pHs. Maximum sorptive capacities (as metal ions) were determined to be 384 μmol g -1 for Cr, 340 μmol g -1 for Ni, 358 μmol g -1 for Fe, 364 μmol g -1 for Mn and 188 μmol g -1 for Pd

  13. Large pore bi-functionalised mesoporous silica for metal ion pollution treatment

    Burke, Aoife M.; Hanrahan, John P. [Department of Chemistry, Materials Section and Supercritical Fluid Centre, University College Cork, Cork (Ireland); Environmental Research Institute (ERI), Lee Road, Cork (Ireland); Healy, David A.; Sodeau, John R. [Department of Chemistry, Centre of Research in Atmospheric Chemistry, University College Cork, Cork (Ireland); Holmes, Justin D. [Department of Chemistry, Materials Section and Supercritical Fluid Centre, University College Cork, Cork (Ireland); Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Dublin 2 (Ireland); Morris, Michael A. [Department of Chemistry, Materials Section and Supercritical Fluid Centre, University College Cork, Cork (Ireland); Environmental Research Institute (ERI), Lee Road, Cork (Ireland); Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Dublin 2 (Ireland)], E-mail: m.morris@ucc.ie

    2009-05-15

    Here we demonstrate aminopropyl and mercatopropyl functionalised and bi-functionalised large pore mesoporous silica spheres to extract various metal ions from aqueous solutions towards providing active sorbents for mitigation of metal ion pollution. Elemental analysis (EA) and FTIR techniques were used to quantify the attachment of the aminopropyl and mercatopropyl functional groups to the mesoporous silica pore wall. Functionalisation was achieved by post-synthesis reflux procedures. For all functionalised silicas the functionalisation refluxing does not alter particle morphology/agglomeration of the particles. It was found that sorptive capacities of the mesoporous silica towards the functional groups were unaffected by co-functionalisation. Powder X-ray diffraction (PXRD) and nitrogen adsorption techniques were used to establish the pore diameters, packing of the pores and specific surface areas of the modified mesoporous silica spheres. Atomic absorption (AA) spectroscopy and inductively coupled plasma-atomic emission spectrometry (ICP-AES) techniques were used to measure the extraction efficiencies of each metal ion species from solution at varying pHs. Maximum sorptive capacities (as metal ions) were determined to be 384 {mu}mol g{sup -1} for Cr, 340 {mu}mol g{sup -1} for Ni, 358 {mu}mol g{sup -1} for Fe, 364 {mu}mol g{sup -1} for Mn and 188 {mu}mol g{sup -1} for Pd.

  14. Exploring Mass Transfer in Mesoporous Zeolites by NMR Diffusometry

    Ryong Ryoo

    2012-04-01

    Full Text Available With the advent of mesoporous zeolites, the exploration of their transport properties has become a task of primary importance for the auspicious application of such materials in separation technology and heterogeneous catalysis. After reviewing the potential of the pulsed field gradient method of NMR (PFG NMR for this purpose in general, in a case study using a specially prepared mesoporous zeolite NaCaA as a host system and propane as a guest molecule, examples of the attainable information are provided.

  15. Shape-Enhanced Photocatalytic Activities of Thoroughly Mesoporous ZnO Nanofibers

    Ren, Xiaolong; Hou, Huilin; Liu, Zhixiong; Gao, Fengmei; Zheng, Jinju; Wang, Lin; Li, Wenge; Ying, Pengzhan; Yang, Weiyou; Wu, Tao

    2016-01-01

    1D mesoporous materials have attracted extensive interest recently, owning to their fascinating properties and versatile applications. However, it remains as a grand challenge to develop a simple and efficient technique to produce oxide nanofibers

  16. Regenerable sorbents for mercury capture in simulated coal combustion flue gas.

    Rodríguez-Pérez, Jorge; López-Antón, M Antonia; Díaz-Somoano, Mercedes; García, Roberto; Martínez-Tarazona, M Rosa

    2013-09-15

    This work demonstrates that regenerable sorbents containing nano-particles of gold dispersed on an activated carbon are efficient and long-life materials for capturing mercury species from coal combustion flue gases. These sorbents can be used in such a way that the high investment entailed in their preparation will be compensated for by the recovery of all valuable materials. The characteristics of the support and dispersion of gold in the carbon surface influence the efficiency and lifetime of the sorbents. The main factor that determines the retention of mercury and the regeneration of the sorbent is the presence of reactive gases that enhance mercury retention capacity. The capture of mercury is a consequence of two mechanisms: (i) the retention of elemental mercury by amalgamation with gold and (ii) the retention of oxidized mercury on the activated carbon support. These sorbents were specifically designed for retaining the mercury remaining in gas phase after the desulfurization units in coal power plants. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Assessment of raw luffa as a natural hollow oleophilic fibrous sorbent for oil spill cleanup

    Ola Abdelwahab

    2014-03-01

    Full Text Available Oil spills have a global concern due to its environmental and economical impact. Various commercial systems have been developed to control these spills, including the use of fibers as sorbents. However, plant biomass is renewable resource that can be converted into useful materials and energy. Luffa, an agricultural waste, was used as a sorbent material. The present study examines the adsorption capacity of raw luffa fibers for different types of oil and water pickup. The investigation revealed that the efficiency of fibers to remove crude oil from sea water was related to the surface properties of the fibers, concentration of the oil, amount of the fibers, as well as the temperature of the crude oil. The results show high sorption efficiency of luffa fibers for different kinds of oil. This sorbent also exhibited a good reusability since the decrease in sorption efficiency did not exceed 50% of the initial value after three sorption cycles.

  18. Strategic Design and Optimization of Inorganic Sorbents for Cesium, Strontium and Actinides

    Maginn, Edward J.

    2009-01-01

    The primary objective of the Notre Dame component of the project was computational in nature. The goal was to provide a design tool for the synthesis of optimized sorbents for the removal of cesium, strontium and actinides from nuclear waste solutions. Molecular modeling enables us to observe and better understand the molecular level interactions that govern the selectivity of specific radionuclides in a particular sorbent. The research focused on the development and validation of a suitable and transferable model for all the cations and ion exchangers of interest, nd then subsequent simulations which determined the siting and mobility of water and cations. Speciic accomplishments include: (1) improving existing intermolecular force fields to accurately model the sorbents of interest; (2) utilizing energy-minimizations and molecular dynamics simulations for structural prediction of CST and niobium-substituted CST materials; (3) determining Na+/water positions in polyoxoniobate materials using molecular dynamics simulations; and (4) developing Hybrid Monte Carlo methods for improved structural prediction.

  19. Adsorption of vitamin E on mesoporous titania nanocrystals

    Shih, C.J.; Lin, C.T.; Wu, S.M.

    2010-01-01

    Tri-block nonionic surfactant and titanium chloride were used as starting materials for the synthesis of mesoporous titania nanocrystallite powders. The main objective of the present study was to examine the synthesis of mesoporous titania nanocrystals and the adsorption of vitamin E on those nanocrystals using X-ray diffraction (XRD), transmission electron microscopy, and nitrogen adsorption and desorption isotherms. When the calcination temperature was increased to 300 o C, the reflection peaks in the XRD pattern indicated the presence of an anatase phase. The crystallinity of the nanocrystallites increased from 80% to 98.6% with increasing calcination temperature from 465 o C to 500 o C. The N 2 adsorption data and XRD data taken after vitamin E adsorption revealed that the vitamin E molecules were adsorbed in the mesopores of the titania nanocrystals.

  20. Electrochemical Hydrogen Storage in a Highly Ordered Mesoporous Carbon

    Dan eLiu

    2014-10-01

    Full Text Available A highly order mesoporous carbon has been synthesized through a strongly acidic, aqueous cooperative assembly route. The structure and morphology of the carbon material were investigated using TEM, SEM and nitrogen adsorption-desorption isotherms. The carbon was proven to be meso-structural and consisted of graphitic micro-domain with larger interlayer space. AC impedance and electrochemical measurements reveal that the synthesized highly ordered mesoporous carbon exhibits a promoted electrochemical hydrogen insertion process and improved capacitance and hydrogen storage stability. The meso-structure and enlarged interlayer distance within the highly ordered mesoporous carbon are suggested as possible causes for the enhancement in hydrogen storage. Both hydrogen capacity in the carbon and mass diffusion within the matrix were improved.

  1. Syntheses and applications of periodic mesoporous organosilica nanoparticles

    Croissant, Jonas G.

    2015-11-06

    Periodic Mesoporous Organosilica (PMO) nanomaterials are envisioned to be one of the most prolific subjects of research in the next decade. Similar to mesoporous silica nanoparticles (MSN), PMO nanoparticles (NPs) prepared from organo-bridged alkoxysilanes have tunable mesopores that could be utilized for many applications such as gas and molecule adsorption, catalysis, drug and gene delivery, electronics, and sensing; but unlike MSN, the diversity in chemical nature of the pore walls of such nanomaterials is theoretically unlimited. Thus, we expect that PMO NPs will attract considerable interest over the next decade. In this review, we will present a comprehensive overview of the synthetic strategies for the preparation of nanoscaled PMO materials, and then describe their applications in catalysis and nanomedicine. The remarkable assets of the PMO structure are also detailed, and insights are provided for the preparation of more complex PMO nanoplatforms.

  2. Adsorption of vitamin E on mesoporous titania nanocrystals

    Shih, C.J., E-mail: cjshih@kmu.edu.tw [Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Lin, C.T.; Wu, S.M. [School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China)

    2010-07-15

    Tri-block nonionic surfactant and titanium chloride were used as starting materials for the synthesis of mesoporous titania nanocrystallite powders. The main objective of the present study was to examine the synthesis of mesoporous titania nanocrystals and the adsorption of vitamin E on those nanocrystals using X-ray diffraction (XRD), transmission electron microscopy, and nitrogen adsorption and desorption isotherms. When the calcination temperature was increased to 300 {sup o}C, the reflection peaks in the XRD pattern indicated the presence of an anatase phase. The crystallinity of the nanocrystallites increased from 80% to 98.6% with increasing calcination temperature from 465 {sup o}C to 500 {sup o}C. The N{sub 2} adsorption data and XRD data taken after vitamin E adsorption revealed that the vitamin E molecules were adsorbed in the mesopores of the titania nanocrystals.

  3. Development and thermochemical characterizations of vermiculite/SrBr_2 composite sorbents for low-temperature heat storage

    Zhang, Y.N.; Wang, R.Z.; Zhao, Y.J.; Li, T.X.; Riffat, S.B.; Wajid, N.M.

    2016-01-01

    Novel EVM/SrBr_2 composite sorbents with different salt contents were developed for low-temperature thermal energy storage (TES). Simulative sorption experiment was conducted to obtain the sorption kinetics diagram and identify threshold salt content that composite sorbents can hold without solution leakage. Distribution of salt embedded in EVM was observed by extreme-resolution scanning electron microscopy (ER-SEM). Thermochemical characterizations including desorption performance and desorption heat were fully investigated by analyzing simultaneous thermal analyzer (STA) results. Results reveal that sorption process of composite sorbents is divided into three parts: water adsorption of EVM, water adsorption of SrBr_2 crystal and liquid-gas absorption of SrBr_2 solution. Since SrBr_2 solution can be hold in macrospores of EVM, water uptake and energy storage density are greatly increased. It appears that the composite sorbent of EVMSrBr_240 is a promising material for thermal energy storage, with water uptake of 0.53 g/g, mass energy storage density of 0.46 kWh/kg and volume energy storage density of 105.36 kWh/m"3. - Highlights: • Vermiculite/SrBr_2 composite sorbents were developed for thermal energy storage. • Water uptake of composite sorbents is divided into three phases. • Energy storage density of each sorption phase is evaluated via calculations. • EVMSrBr_240 is chosen as optimal sorbent without solution leakage.

  4. Soft templated mesoporous carbons: Tuning the porosity for the adsorption of large organic pollutants

    Libbrecht, Wannes; Verberckmoes, An; Thybaut, Joris; Van Der Voort, Pascal; De Clercq, Jeriffa

    2017-01-01

    Mesoporous carbons have been the subject of various studies, both fundamental and applied. Fundamental studies revealed numerous synthesis routes which can adjust material characteristics as specific surface area, pore volume, pore size or morphology and elemental composition. The indirect synthesis or hard template method was developed first. An extensive collection of template materials exist, which can be impregnated with carbon precursors to provide various hard templated mesoporous carbo...

  5. Ordered mesoporous silica-based inorganic nanocomposites

    Wang Qingqing; Shantz, Daniel F.

    2008-01-01

    This article reviews the synthesis and characterization of nanoparticles and nanowires grown in ordered mesoporous silicas (OMS). Summarizing work performed over the last 4 years, this article highlights the material properties of the final nanocomposite in the context of the synthesis methodology employed. While certain metal-OMS systems (e.g. gold in MCM-41) have been extensively studied this article highlights that there is a rich set of chemistries that have yet to be explored. The article concludes with some thoughts on future developments and challenges in this area. - Graphical abstract: HAADF TEM image of gold nanoparticles in amine-functionalized MCM-41 (from Ref. [22])

  6. Application of mesoporous carbon and modified mesoporous carbon for treatment of DMF sewage

    Liu, Fang, E-mail: liufangfw@163.com; Gao, Ya; Zhang, Shuang; Yan, Xi; Fan, Fengtao; Zhao, Chaocheng; Sun, Juan [China University of Petroleum(East China), Department of Chemical Engineering (China)

    2016-02-15

    Mesoporous carbon (MC) was prepared in soft template, and potassium ferricyanide was added into MC to prepare the modified mesoporous carbon (MMC). TEM, SEM, FT-IR, and N{sub 2} adsorption–desorption were used to characterize the textural properties of mesoporous materials. The BET specific surface area, pore volume, and the pore size of MC and MMC were 607.6321 and 304.7475 m{sup 2}/g, 0.313552 and 0.603573 cm{sup 3}/g, and 5.4356 and 7.9227 nm, respectively. The adsorption capabilities of MC and MMC were compared with the silica mesoporous material MCM-41. The influences of different adsorption conditions were optimized. For MC, the optimums of adsorbent dose, DMF initial concentration, rotating speed, and pH were 0.002 mg/50 mL, 200 mg/L, 200 r/min, and 4, respectively. MMC showed the highest DMF adsorption capacity at adsorbent dose 0.002 g/50 mL, DMF initial concentration 1000 mg/L, rotating speed 1000 r/min, pH more than 9, and contact time of less than 20 min. Meanwhile for MC, MMC, Pseudo-second-order equation was used to fit adsorption kinetics data. And adsorption process could be well fitted by Langmuir and Freundlich adsorption isotherms of MC, MMC. The results showed that MMC was a perfect adsorbent for DMF, and it was easy to separation and recycle. The recycling property of MMC was still relatively better than other two adsorbents.

  7. Durable zinc oxide-containing sorbents for coal gas desulfurization

    Siriwardane, Ranjani V.

    1996-01-01

    Durable zinc-oxide containing sorbent pellets for removing hydrogen sulfide from a gas stream at an elevated temperature are made up to contain titania as a diluent, high-surface-area silica gel, and a binder. These materials are mixed, moistened, and formed into pellets, which are then dried and calcined. The resulting pellets undergo repeated cycles of sulfidation and regeneration without loss of reactivity and without mechanical degradation. Regeneration of the pellets is carried out by contacting the bed with an oxidizing gas mixture.

  8. Pore Characteristics and Hydrothermal Stability of Mesoporous Silica: Role of Oleic Acid

    Junhyun Choi

    2014-01-01

    Full Text Available Silicate mesoporous materials were synthesized with nonionic surfactant and their surfaces were modified by oleic acid adsorption. Infrared spectrometer, nitrogen adsorption-desorption isotherm, scanning electron microscopy, and thermogravimetric analyses were used to investigate the structure of oleic acid modified mesoporous material. The effects of heat treatment at various temperatures on oleic acid modified materials were also studied. Oleic acids on silica surfaces were found to be bonded chemically and/or physically and be capable of enduring up to 180°C. The adsorbed oleic acid improved the hydrothermal stability of mesoporous silica and assisted mesopore structure to grow more in hydrothermal treatment process by preventing the approach of water.

  9. General strategy for fabricating thoroughly mesoporous nanofibers

    Hou, Huilin; Wang, Lin; Gao, Fengmei; Wei, Guodong; Tang, Bin; Yang, Weiyou; Wu, Tao

    2014-01-01

    mesoporous nanofibers with high purity and uniformity. Here, we report a general, simple and cost-effective strategy, namely, foaming-assisted electrospinning, for producing mesoporous nanofibers with high purity and enhanced specific surface areas. As a

  10. "Bricks and mortar" self-assembly approach to graphitic mesoporous carbon nanocomposites

    Fulvio, P. F.; Mayes, R.; Wang, X. Q.; Mahurin, S., M.; Bauer, J. C.; Presser, V.; McDonough, J.; Gogotsi, Y.; Dai, S.

    2011-04-20

    Mesoporous carbon materials do not have sufficient ordering at the atomic scale to exhibit good electronic conductivity. To date, mesoporous carbons having uniform mesopores and high surface areas have been prepared from partially-graphitizable precursors in the presence of templates. High temperature thermal treatments above 2000 °C, which are usually required to increase conductivity, result in a partial or total collapse of the mesoporous structures and reduced surface areas induced by growth of graphitic domains, limiting their applications in electric double layer capacitors and lithium-ion batteries. In this work, we successfully implemented a “brick-and-mortar” approach to obtain ordered graphitic mesoporous carbon nanocomposites with tunable mesopore sizes below 850 °C without using graphitization catalysts or high temperature thermal treatments. Phenolic resin-based mesoporous carbons act as mortar to highly conductive carbon blacks and carbon onions (bricks). The capacitance and resistivity of final materials can be tailored by changing the mortar to brick ratios.

  11. Application of inorganic sorbents for sewage purification from copper

    Yelizarova, I.A.; Tomchuk, T.K.; Kalinin, N.F.; Vol'khin, V.V.; Levichek, M.S.; Gulyaeva, E.I.

    1986-01-01

    Article presents the results of elaboration of synthesis methods of sorbent on the base of phosphate and magnesium hydroxide. As a result of study the technology of sorbent production with optimal properties was elaborated.

  12. Immobilized humic substances and immobilized aggregates of humic substances as sorbent for solid phase extraction.

    Erny, Guillaume L; Gonçalves, Bruna M; Esteves, Valdemar I

    2013-09-06

    In this work, humic substances (HS) immobilized, as a thin layer or as aggregates, on silica gel were tested as material for solid phase extraction. Some triazines (simazine, atrazine, therbutylazine, atrazine-desethyl-desisopropyl-2-hydroxy, ametryn and terbutryn), have been selected as test analytes due to their environmental importance and to span a large range of solubility and octanol/water partition coefficient (logP). The sorbent was obtained immobilizing a thin layer of HS via physisorption on a pre-coated silica gel with a cationic polymer (polybrene). While the sorbent could be used as it is, it was demonstrated that additional HS could be immobilized, via weak interactions, to form stable humic aggregates. However, while a higher quantity of HS could be immobilized, no significant differences were observed in the sorption parameters. This sorbent have been tested for solid phase extraction to concentrate triazines from aqueous matrixes. The sorbent demonstrated performances equivalent to commercial alternatives as a concentration factor between 50 and 200, depending on the type of triazines, was obtained. Moreover the low cost and the high flow rate of sample through the column allowed using high quantity of sorbent. The analytical procedure was tested with different matrixes including tap water, river water and estuarine water. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Long Life Moving-Bed Zinc Titanate Sorbent

    Copeland, Robert J.; Cesario, Mike; Feinberg, Daniel A.; Sibold, Jack; Windecker, Brian; Yang, Jing

    1997-01-01

    The objective of this work was to develop and test long-life sorbents for hot gas cleanup. Specifically, we measured the sulfur loading at space velocities typically used for absorption of H 2 S and regenerated the sorbent with diluted air for multiple cycles. Based on the experimental results, we prepared a conceptual design of the sorbent-fabrication system, and estimated the cost of sorbent production and of sulfur removal

  14. Experimentation of netlike hydro gel nitrogen containing polymer sorbents for biological liquids purification

    Karieva, Z.M.; Karimova, N. Kh.

    2003-01-01

    The high efficiency of hydrogels synthesized earlier in comparison with Pharmacopoeia sorbents are interesting to study comprehensively for the number of the toxins of biological liquids. Taking into considerations the high electoral sorption ability of ethynilpiperidol polymers to the hydro phobic interaction it may be suggested that they have a high detoxication ability. The detoxication characteristics of studied polymers have advantages over the known sorbents. Experiences with animals showed that in identical conditions of experiment in application of netlike polymers the survival grew 90%. Synthesis and investigations of netlike hydrogels polymer materials on nitrogen containing monomers of ethynil piperidol were given in the work. (author)

  15. Bone tissue engineering using silica-based mesoporous nanobiomaterials:Recent progress.

    Shadjou, Nasrin; Hasanzadeh, Mohammad

    2015-10-01

    Bone disorders are of significant concern due to increase in the median age of our population. It is in this context that tissue engineering has been emerging as a valid approach to the current therapies for bone regeneration/substitution. Tissue-engineered bone constructs have the potential to alleviate the demand arising from the shortage of suitable autograft and allograft materials for augmenting bone healing. Silica based mesostructured nanomaterials possessing pore sizes in the range 2-50 nm and surface reactive functionalities have elicited immense interest due to their exciting prospects in bone tissue engineering. In this review we describe application of silica-based mesoporous nanomaterials for bone tissue engineering. We summarize the preparation methods, the effect of mesopore templates and composition on the mesopore-structure characteristics, and different forms of these materials, including particles, fibers, spheres, scaffolds and composites. Also, the effect of structural and textural properties of mesoporous materials on development of new biomaterials for production of bone implants and bone cements was discussed. Also, application of different mesoporous materials on construction of manufacture 3-dimensional scaffolds for bone tissue engineering was discussed. It begins by giving the reader a brief background on tissue engineering, followed by a comprehensive description of all the relevant components of silica-based mesoporous biomaterials on bone tissue engineering, going from materials to scaffolds and from cells to tissue engineering strategies that will lead to "engineered" bone. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. MCM-41介孔碳材料的合成及其电化学性能%Synthesis of MCM-41 Mesoporous Carbon Materials and Their Electrochemical Performance

    宋伟明; 徐立洋; 孙立; 邓启刚; 冯建; 程晓宇

    2017-01-01

    以十六烷基三甲基溴化铵(CTAB)为模板剂,可溶性淀粉(Starch)为碳源,通过软模板法一步合成了高度有序的介孔碳材料.通过热重分析(TG)、X射线衍射(XRD)、N2吸附-脱附和透射电子显微镜(TEM)对材料的结构进行了表征.结果表明:当m(模板剂CTAB)∶m(可溶性淀粉)=1.0∶1.5,650℃焙烧碳化3h,并用氢氟酸去除二氧化硅后,所得到的MCM-41有序介孔碳材料(OMC-650)的比表面积为985 m2/g,平均孔径为2.5nm,且孔径分布均匀.XRD和FEM分析结果表明,OMC-650具有典型的MCM-41结构特征,有序性良好.以OMC-650作为工作电极,氧化汞为参比电极,铂为辅助电极,用6 mol/L KOH做电解液,测其比电容为150 F/g,且经过1 000次充放电循环后,其比电容仍为138 F/g,为原电容的92%,说明所合成的材料具有良好的电容稳定性.%A highly ordered mesoporous carbon material was synthesized by a soft template method with hexadecyltrimethylammonium bromide (CTAB) as a template and soluble starch (Starch) as a carbon source.The structures of the resultant materials were characterized by thermal gravimetric analysis (TG),X-ray diffraction (XRD),N2 adsorption-desorption isotherms and transmission electron microscopy (TEM).The results showed that MCM-41 ordered mesoporous carbon material (OMC-650) was obtained when the mass ratio of CTAB to Starch was 1.0∶1.5,carbonized for 3 h at 650 ℃,and then removing the silica with hydrofluoric acid.OMC-650 possessed specific surface area of 985 m2/g and average pore diameter of 2.5 nm and exhibited a uniform distribution.XRD and TEM analysis showed that OMC-650 possesses a typical MCM-41 structural feature with high ordered structure.The electrochemical tests were conducted in a three-electrode system in 6 mol/L KOH solution.When OMC-650 was used as a working electrode,mercury oxide electrode was used as a reference electrode,and Pt wire electrode served as an auxiliary electrode.The specific capacitance of

  17. Efficiency of sugarcane bagasse-based sorbents for oil removal from engine washing wastewater.

    Guilharduci, Viviane Vasques da Silva; Martelli, Patrícia Benedini; Gorgulho, Honória de Fátima

    2017-01-01

    This work evaluates the efficiency of sugarcane bagasse-based sorbents in the sorption of oil from engine washing wastewater. The sorbents were obtained from sugarcane bagasse in the natural form (SB-N) and modified with either acetic anhydride (SB-Acet) or 3-aminopropyltriethoxysilane (SB-APTS). The results showed that the sorption capacity of these materials decreased in the following order: SB-APTS > SB-N > SB-Acet. The superior oil sorption capacity observed for SB-APTS was attributed to the polar amino end groups in the silane structure, which acted to increase the hydrophilic character of the fibers. However, all the sorbents obtained in this study were able to clean a real sample of wastewater from engine washing, leading to significant reductions in suspended matter, sediment, anionic surfactants, and turbidity.

  18. Alkaline sorbent injection for mercury control

    Madden, Deborah A.; Holmes, Michael J.

    2002-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  19. Topical Report 5: Sorbent Performance Report

    Krutka, Holly; Sjostrom, Sharon

    2011-05-31

    ADA-ES has completed an extensive sorbent screening program funded primarily through DOE NETL cooperative agreement DE-NT0005649 with support from EPRI and industry cost-share participants. Tests were completed on simulated and actual flue gas. The overall project objective is to address the viability and accelerate development of a solid-based postcombustion CO2 capture technology that can be retrofit to the existing fleet of coal-fired power plants. An important component of the viability assessment was to evaluate the state of development of sorbents and measure key performance characteristics under realistic operating conditions.

  20. Desulfurization Sorbents for Transport-Bed Applications

    Gupta, Raghubir P.; Turk, Brian S.; Vierheilig, Albert A.

    1997-01-01

    This project extends the prior work on the development of fluidizable zinc titanate particles using a spray-drying technique to impart high reactivity and attrition resistance. The specific objectives are: (1) To develop highly reactive and attrition-resistant zinc titanate sorbents in 40- to 150-(micro)m particle size range for transport reactor applications; (2) To transfer sorbent production technology to private sector; and (3) To provide technical support to Sierra Pacific Clean Coal Technology Demonstration plant and FETC's Hot-Gas Desulfurization Process Development Unit (PDU), both employing a transport reactor system

  1. Influence of lignin on properties of wood-inorganic sorbents

    Remez, V.P.; Charina, M.V.; Klass, S.M.; Shubin, A.S.; Tkachev, K.V.; Isaeva, O.F.

    1986-01-01

    Present article is devoted to influence of lignin on properties of wood-inorganic sorbents. The influence of component composition of matrix on sorption properties of sorbents and their stability in different mediums is studied. The dependence of sorption capacity of sorbent on component matrix composition and its porous structure is defined.

  2. Anaerobic co-digestion of cork based oil sorbent and cow manure or sludge

    Cavaleiro, A.J.; Neves, T.M.; Guedes, A.P.; Alves, M.M.; Pinto, P.; Silva, S.P.; Machado de Sousa, Diana

    2015-01-01

    Cork, a material with great economic, social and environmental importance in Portugal, is also a good oil sorbent that can be used in the remediation of oil spills. The oil-impregnated cork can be easily removed, but requires further treatment. In the case of vegetable oil spills, anaerobic

  3. Adsorption of gaseous RuO4 by various sorbents. II

    Vujisic, L.; Nikolic, R.

    1983-01-01

    Sorption of gaseous RuO 4 on impregnated Alcoa Alumina H-151, impregnated charcoal, silica gel and HEPA filter was investigated. The results obtained on various sorbents are compared and discussed in connection with possibilities to use the chosen material in air cleaning systems

  4. Cubic mesoporous Ag@CN: a high performance humidity sensor.

    Tomer, Vijay K; Thangaraj, Nishanthi; Gahlot, Sweta; Kailasam, Kamalakannan

    2016-12-01

    The fabrication of highly responsive, rapid response/recovery and durable relative humidity (%RH) sensors that can precisely monitor humidity levels still remains a considerable challenge for realizing the next generation humidity sensing applications. Herein, we report a remarkably sensitive and rapid %RH sensor having a reversible response using a nanocasting route for synthesizing mesoporous g-CN (commonly known as g-C 3 N 4 ). The 3D replicated cubic mesostructure provides a high surface area thereby increasing the adsorption, transmission of charge carriers and desorption of water molecules across the sensor surfaces. Owing to its unique structure, the mesoporous g-CN functionalized with well dispersed catalytic Ag nanoparticles exhibits excellent sensitivity in the 11-98% RH range while retaining high stability, negligible hysteresis and superior real time %RH detection performances. Compared to conventional resistive sensors based on metal oxides, a rapid response time (3 s) and recovery time (1.4 s) were observed in the 11-98% RH range. Such impressive features originate from the planar morphology of g-CN as well as unique physical affinity and favourable electronic band positions of this material that facilitate water adsorption and charge transportation. Mesoporous g-CN with Ag nanoparticles is demonstrated to provide an effective strategy in designing high performance %RH sensors and show great promise for utilization of mesoporous 2D layered materials in the Internet of Things and next generation humidity sensing applications.

  5. Mesoporous silica nanoparticles as vectors for gene therapy

    Crapina, Laura Cipriano; Bizeto, Marcos, E-mail: lauracrapina@hotmail.com [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil)

    2016-07-01

    Full text: Mesoporous silica nanoparticles present unique physical-chemical properties, such as high surface area, tunable pore size, easy surface chemical modification, good biocompatibility and low toxicology. Those properties make this class of inorganic materials promising for several potential applications in the biomedical field. This work seeks to develop mesoporous silica nanoparticles with characteristics suitable to the transport of nucleic acids, such as plasmid DNA and microRNA, with the aim of substituting viral vectors in gene therapy. A successful nanocarrier must have positive charge at physiological conditions and pore diameter larger than 30 Å. The mesoporous silica was synthesized according to the method described by Bein and collaborators [1]. Based on a cocondensation synthetic route, positively charged nanoparticles were obtained through the insertion of N-3-(trimethoxysilyl)propyldiethylenetriamine in the silica walls. Pore expansion was achieved through the incorporation of 1,2,4- trimethylbenzene into the hexadecyltrimethylammonium micellar aggregates, which are a structure-directing agent for the mesopores. The resulting nanoparticles were characterized by DLS, ζ potential, XRD, FTIR, SEM, TEM, TGA and elemental analysis. In addition, the capability of nucleic acid adsorption was tested and confirmed by gel electrophoresis. Discovery of a non-viral therapeutic agent would aid the viability of gene therapy, which is a treatment for chronic ischemia, metabolic and genetic disorders. Reference: [1] K. Moeller, J. Kobler, T. Bein, Journal of Materials Chemistry, 17, 624-631, (2007). (author)

  6. A flexible, bolaamphiphilic template for mesoporous silicas.

    Yuen, Alexander K L; Heinroth, Falk; Ward, Antony J; Masters, Anthony F; Maschmeyer, Thomas

    2013-08-28

    A novel symmetrical bolaamphiphile, containing two N-methylimidazolium head-groups bridged by a 32-methylene linker, was synthesized and characterized. A variety of mesoporous silicas was prepared using the bolaamphiphile as a "soft template". The effects of absolute surfactant concentration and synthesis conditions upon the morphologies of these silicas were investigated. For a given surfactant concentration, particle morphology; pore size; and pore ordering were modified through control of the template to silica-precursor ratio and synthesis conditions. Observed morphologies included: lenticular core-shell nanoparticles and decorticated globules, truncated hexagonal plates, and sheets. In all cases the mesopores are aligned along the shortest axis of the nanomaterial. Decorticated materials displayed surface areas of up to 1200 m(2) g(-1) and pore diameters (D(BJH)) of 24-28 Å. Small-angle X-ray diffraction and transmission electron microscopy measurements revealed that the majority of the materials has elliptical pores arranged in rectangular lattices (c2mm). Adoption of this symmetry group is a result of the template aggregate deformation from a regular hexagonal phase of cylindrical rods to a ribbon phase under the synthetic conditions.

  7. Evaluation of Dry Sorbent Injection Technology for Pre-Combustion CO{sub 2} Capture

    Richardson, Carl [URS Group, Inc., Austin, TX (United States); Steen, William [URS Group, Inc., Austin, TX (United States); Triana, Eugenio [URS Group, Inc., Austin, TX (United States); Machalek, Thomas [URS Group, Inc., Austin, TX (United States); Davila, Jenny [URS Group, Inc., Austin, TX (United States); Schmit, Claire [URS Group, Inc., Austin, TX (United States); Wang, Andrew [URS Group, Inc., Austin, TX (United States); Temple, Brian [URS Group, Inc., Austin, TX (United States); Lu, Yongqi [Illinois State Geological Survey - University of Illinois at Urbana-Champaign (United States); Lu, Hong [Illinois State Geological Survey - University of Illinois at Urbana-Champaign (United States); Zhang, Luzheng [Illinois State Geological Survey - University of Illinois at Urbana-Champaign (United States); Ruhter, David [Illinois State Geological Survey - University of Illinois at Urbana-Champaign (United States); Rostam-Abadi, Massoud [Illinois State Geological Survey - University of Illinois at Urbana-Champaign (United States); Sayyah, Maryam [Illinois State Geological Survey - University of Illinois at Urbana-Champaign (United States); Ito, Brandon [Illinois State Geological Survey - University of Illinois at Urbana-Champaign (United States); Suslick, Kenneth [Illinois State Geological Survey - University of Illinois at Urbana-Champaign (United States)

    2013-09-30

    This document summarizes the work performed on Cooperative Agreement DE-FE0000465, “Evaluation of Dry Sorbent Technology for Pre-Combustion CO{sub 2} Capture,” during the period of performance of January 1, 2010 through September 30, 2013. This project involves the development of a novel technology that combines a dry sorbent-based carbon capture process with the water-gas-shift reaction for separating CO{sub 2} from syngas. The project objectives were to model, develop, synthesize and screen sorbents for CO{sub 2} capture from gasified coal streams. The project was funded by the DOE National Energy Technology Laboratory with URS as the prime contractor. Illinois Clean Coal Institute and The University of Illinois Urbana-Champaign were project co-funders. The objectives of this project were to identify and evaluate sorbent materials and concepts that were suitable for capturing carbon dioxide (CO{sub 2}) from warm/hot water-gas-shift (WGS) systems under conditions that minimize energy penalties and provide continuous gas flow to advanced synthesis gas combustion and processing systems. Objectives included identifying and evaluating sorbents that efficiently capture CO{sub 2} from a gas stream containing CO{sub 2}, carbon monoxide (CO), and hydrogen (H{sub 2}) at temperatures as high as 650 °C and pressures of 400-600 psi. After capturing the CO{sub 2}, the sorbents would ideally be regenerated using steam, or other condensable purge vapors. Results from the adsorption and regeneration testing were used to determine an optimal design scheme for a sorbent enhanced water gas shift (SEWGS) process and evaluate the technical and economic viability of the dry sorbent approach for CO{sub 2} capture. Project work included computational modeling, which was performed to identify key sorbent properties for the SEWGS process. Thermodynamic modeling was used to identify optimal physical properties for sorbents and helped down-select from the universe of possible sorbent

  8. Alendronate functionalized mesoporous hydroxyapatite nanoparticles for drug delivery

    Li, Dongdong; Zhu, Yuntao; Liang, Zhiqiang

    2013-01-01

    Highlights: ► The synthesized mesoporous hydroxyapatite has nanostructure and bioactivity. ► The materials have high surface area and amino group. ► The materials show higher drug loading and slower release rate than pure HAP. - Abstract: Mesoporous nanosized hydroxyapatite (HAP) functionalized by alendronate (ALN) was synthesized using cationic surfactant CTAB as template. The structural, morphological and textural properties were fully characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and N 2 adsorption/desorption. Then the obtained materials were performed as drug delivery carriers using ibuprofen (IBU) as a model drug to investigate their drug storage/release properties in simulated body fluid (SBF). The materials showed relatively slower release rate compared with HAP due to the ionic interaction between -NH 3 + on the matrix and -COO − belongs to IBU. The system provides a new concept for improving the drug loading or slowing down the release rate

  9. Stochastic analysis of capillary condensation in disordered mesopores.

    Gommes, Cedric J; Roberts, Anthony P

    2018-05-08

    Most mesoporous materials of practical interest are inherently disordered, which has a significant impact on the condensation and evaporation of vapours in their pores. Traditionally, the effect of disorder is theoretically analyzed in a perturbative approach whereby slight elements of disorder (constriction, corrugation) are added to geometrically ideal pores. We propose an alternative approach, which consists of using a stochastic geometrical model to describe both the porous material and the condensate within the pores. This is done through a multiphase generalisation of the standard Gaussian random field model of disordered materials. The model parameters characterising the condensate provide a low-dimensional approximation of its configuration space, and we use a Derjaguin-Broekhoff-de Boer approximation to calculate the free-energy landscape. Our analysis notably questions the existence of vapour-like metastable states in realistically disordered mesoporous materials. Beyond capillary condensation, our general methodology is applicable to a broad array of confined phenomena.

  10. 一步法合成载铁有序介孔碳材料的形成机理%Mechanism of the synthesis of ordered Fe-containing mesoporous carbon composite materials in one-pot

    凌晓凤; 顾娟; 李健生; 孙秀云; 韩卫清; 沈锦优; 王连军

    2012-01-01

    采用软模板路线以三嵌段共聚物F127为模板剂,间苯二酚-甲醛缩聚所形成酚醛树脂(RF)为碳源,与酚羟基有络合作用的无机铁盐为金属前体,在无外加酸碱催化剂的条件下,利用铁盐的水解反应形成酚醛缩聚所需酸性环境,多组分共组装一步合成了载铁有序介孔碳材料(Fe/OMC)。对Fe/OMC合成各阶段过程进行了分析,利用X射线衍射、透射电子显微镜等手段对材料进行表征,比较了不同老化时间、硝酸铁投加量及酚醛比例等合成条件对材料结构的影响规律。结果表明,在较长的老化时间(≥60 h)、适宜的n(Fe)/n(R)比(0.05~0.2)和n(R)/n(F)比[(1/1.5)~(1/2)]条件下,均可形成有序的介孔结构。在此基础上,提出了载铁有序介孔碳材料的形成机理。%Ordered Fe-containing mesoporous carbon composite materials(Fe/OMC)have been synthesized via soft-templating routes by using triblock copolymer F127 as a template agent,resorcinol(R)-formaldehyde(F)as a carbon precursor,inorganic iron salts having complex reaction with phenols as a metal precursor in one-pot.The main strategy of this approach was to utilize the acidity self-generated from the hydrolysis of inorganic salts in the aqueous solutions as the catalyst for RF polymerization,where no addition of mineral acids was necessary.The resultant Fe/OMC materials were characterized by X-ray diffraction,Transmission electron microscopy.The influences of the aging time,the dosage of iron nitrate and the molar ratio of R/F on the structure of the obtained materials were investigated.Results show that the ordered mesoporous structure can be obtained under the synthetic condition of the aging time≥60 h,n(Fe)/n(R)=0.05— 0.2,n(R)/n(F)=1/1.5— 1/2.0.Moreover,a possible mechanism of the synthesis of Fe/OMC was proposed.

  11. EVALUATION OF SOLID SORBENTS AS A RETROFIT TECHNOLOGY FOR CO2 CAPTURE FROM COAL-FIRED POWER PLANTS

    Holly Krutka; Sharon Sjostrom

    2011-07-31

    Through a U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) funded cooperative agreement DE-NT0005649, ADA Environmental Solutions (ADA) has begun evaluating the use of solid sorbents for CO{sub 2} capture. The project objective was to address the viability and accelerate development of a solid-based CO{sub 2} capture technology. To meet this objective, initial evaluations of sorbents and the process/equipment were completed. First the sorbents were evaluated using a temperature swing adsorption process at the laboratory scale in a fixed-bed apparatus. A slipstream reactor designed to treat flue gas produced by coal-fired generation of nominally 1 kWe was designed and constructed, which was used to evaluate the most promising materials on a more meaningful scale using actual flue gas. In a concurrent effort, commercial-scale processes and equipment options were also evaluated for their applicability to sorbent-based CO{sub 2} capture. A cost analysis was completed that can be used to direct future technology development efforts. ADA completed an extensive sorbent screening program funded primarily through this project, DOE NETL cooperative agreement DE-NT0005649, with support from the Electric Power Research Institute (EPRI) and other industry participants. Laboratory screening tests were completed on simulated and actual flue gas using simulated flue gas and an automated fixed bed system. The following types and quantities of sorbents were evaluated: 87 supported amines; 31 carbon based materials; 6 zeolites; 7 supported carbonates (evaluated under separate funding); and 10 hydrotalcites. Sorbent evaluations were conducted to characterize materials and down-select promising candidates for further testing at the slipstream scale. More than half of the materials evaluated during this program were supported amines. Based on the laboratory screening four supported amine sorbents were selected for evaluation at the 1 kW scale at two different

  12. Arsenic removal using natural biomaterial-based sorbents.

    Ansone, Linda; Klavins, Maris; Viksna, Arturs

    2013-10-01

    Arsenic contamination of water is a major problem worldwide. A possible solution can be approached through developing new sorbents based on cost-effective and environmentally friendly natural biomaterials. We have developed new sorbents based on biomaterial impregnation with iron oxyhydroxide. In this study, raw peat material, iron-modified peat, iron-modified biomass (shingles, straw, sands, cane and moss) as well as iron humate were used for the removal of arsenate from contaminated water. The highest sorption capacity was observed in iron-modified peat, and kinetic studies indicated that the amount of arsenic sorbed on this material exceeds 90 % in 5 h. Arsenate sorption on iron-modified peat is characterised by the pseudo-second-order mechanism. The results of arsenic sorption in the presence of competing substances indicated that sulphate, nitrate, chloride and tartrate anions have practically no influence on As(V) sorption onto Fe-modified peat, whereas the presence of phosphate ions and humic acid significantly lowers the arsenic removal efficiency.

  13. Use of rice husk ash as only source of silica in the formation of mesoporous materials Emprego da cinza da casca de arroz como única fonte de sílica na formação de materiais mesoporosos

    A. J. Schwanke

    2013-03-01

    Full Text Available This paper reports the synthesis of molecular sieves similar to MCM-41 using rice husk ash as only source of silica. For comparison purposes, a standard synthesis was performed using aerosil 200 commercial silica. The rice husk silica was obtained by heating treatment at 600 ºC and leaching for 2 h in reflux with HCl 1mol.L-1 and used in the synthesis. The samples prepared were characterized by N2 adsorption, X-ray diffraction (XRD, scanning electronic microscopy (SEM and thermogravimetric analysis (TG. By type-IV adsorption isotherms, the formation of mesoporous materials was observed. XRD showed the formation of hexagonal unidirectional pore materials similar to MCM-41. By SEM, it could be observed that the rice husk has fibrous aspect and that synthesis using calcined and leached rice husk did not react entirely because silica was only partially dissolved.Este trabalho relata o estudo da síntese de peneiras moleculares semelhantes à MCM-41, empregando cinza da casca de arroz como única fonte de sílica. Para critérios de comparação uma síntese foi realizada com sílica comercial aerosil 200. A sílica da casca de arroz foi obtida mediante tratamento térmico a 600 ºC e lixiviação em refluxo por 2 h com HCl 1 mol/L e empregada na síntese. As amostras preparadas foram caracterizadas por adsorção de N2, difração de raios X, microscopia eletrônica de varredura (MEV e termogravimetria. Por meio das isotermas de adsorção, do tipo IV, observa-se a formação de material mesoporoso. Nos difratogramas de raios X é identificada a formação hexagonal unidirecional de poros, indicando que material apresenta semelhanças com a MCM-41. Por MEV observa-se que a casca de arroz possui aspecto fibroso e que a síntese empregando a casca de arroz calcinada e lixiviada não reagiu na sua totalidade devido a dissolução parcial da sílica.

  14. Synthesis and application of nano-, meso- and macroporous sorbents based on lignin for detoxication of biological fluids

    Chopabayeva, Nazira N.; Mukanov, Kanatbek N.; Tasmagambet, Amandyk T.

    2014-05-01

    Novel nano-, meso- and macroporous sorbents based on hydrolysis lignin have been synthesized by catalytic o-alkylation of biolpolymer with epoxy resin ED-20 and subsequent amination of formed α-oxyde derivative. Composition, structure, morphology and physical, chemical properties of ion-exchangers were investigated by FTIR, SEM, TEM, porosimetry and potentiometric titration method. It has been established that alkaline activated lignin shows an increase of SBET to 20.9 m2/g while modification leads to decrease of SBET more than double (from 9.2 to 5.2 m2/g) that of an untreared sample (14.5 m2/g). Synthesized sorbents are characterized by approximately identical mesoporous structure and mainly contained a pore size of 10-14 nm. The results clearly demonstrate the efficiency of lignin based sorbents for the removal of water and lipid soluble toxic metabolites from blood serum of diabetic retinopathy patients. Samples reduced the high level of total cholesterol, including its most atherogenic fractions (LDL-C, VLDL-C), triglyceride to the level of optimum compensated diabetes without significant removal of HDL-C. Concentration of glucose was decreased to physiological norms.

  15. Shape-Enhanced Photocatalytic Activities of Thoroughly Mesoporous ZnO Nanofibers

    Ren, Xiaolong

    2016-06-24

    1D mesoporous materials have attracted extensive interest recently, owning to their fascinating properties and versatile applications. However, it remains as a grand challenge to develop a simple and efficient technique to produce oxide nanofibers with mesoporous architectures, controlled morphologies, large surface areas, and optimal performances. In this work, a facile foaming-assisted electrospinning strategy with foaming agent of tea saponin is used to produce thoroughly mesoporous ZnO nanofibers with high purity and controlled morphology. Interestingly, mesoporous fibers with elliptical cross-section exhibit the significantly enhanced photocatalytic activity for hydrogen production, as compared to the counterparts with circular and rectangular cross-sections, and they also perform better than the commercial ZnO nanopowders. The unexpected shape dependence of photocatalytic activities is attributed to the different stacking modes of the mesoporous fibers, and a geometrical model is developed to account for the shape dependence. This work represents an important step toward producing thoroughly mesoporous ZnO nanofibers with tailored morphologies, and the discovery that fibers with elliptical cross-section render the best performance provides a valuable guideline for improving the photocatalytic performance of such mesoporous nanomaterials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Core/shell magnetic mesoporous silica nanoparticles with radially oriented wide mesopores

    Nikola Ž. Knežević

    2014-06-01

    Full Text Available Core/shell nanoparticles, containing magnetic iron-oxide (maghemite core and mesoporous shell with radial porous structure, were prepared by dispersing magnetite nanoparticles and adding tetraethylorthosilicate to a basic aqueous solution containing structure-templating cetyltrimethylammonium bromide and a pore-swelling mesithylene. The material is characterized by SEM and TEM imaging, nitrogen sorption and powder X-ray diffraction. Distinctive features of the prepared material are its high surface area (959 m2/g, wide average pore diameter (12.4 nm and large pore volume (2.3 cm3/g. The material exhibits radial pore structure and the high angle XRD pattern characteristic for maghemite nanoparticles, which are obtained upon calcination of the magnetite-containing material. The observed properties of the prepared material may render the material applicable in separation, drug delivery, sensing and heterogeneous catalysis.

  17. Radon adsorption in fibrous carbon sorbents

    Anshakov, O.M.; Kish, A.O.; Chudakov, V.A.; Matvejchuk, S.V.; Sokolovskij, A.S.; Ugolev, I.I.

    2006-01-01

    Radon sorption in woven fibrous sorbents 'AUT-M' and 'Busofit' and nonwoven fiber in the temperature range 0-50 degrees centigrade was studied. Adsorption heat of radon from the ambient air in different types of carbon fiber was determined. (authors)

  18. Graphene encapsulated Fe3O4 nanorods assembled into a mesoporous hybrid composite used as a high-performance lithium-ion battery anode material

    Huang, Wei; Xiao, Xinxin; Engelbrekt, Christian

    2017-01-01

    The discovery of new anode materials and engineering their fine structures are the core elements in the development of new-generation lithium ion batteries (LIBs). To this end, we herein report a novel nanostructured composite consisting of approximately 75% Fe3O4 nanorods and 25% reduced graphene...

  19. The influence of reactivation by hydration of spent SO{sub 2} sorbents on their impact fragmentation in fluidized bed combustors

    Montagnaro, F.; Salatino, P.; Santoro, L.; Scala, F. [University of Naples Federico II, Naples (Italy)

    2010-09-01

    The relationship between calcination/sulphation and attrition/fragmentation of calcium-based SO{sub 2} sorbents in fluidized bed (FB) combustors has long been recognized, but only recently did attrition by impact receive due consideration. There is limited available information in the literature on the propensity of exhausted calcium-based sorbents to undergo high-velocity impact fragmentation after they have been reactivated by steam or water hydration. The present study addresses the relationship between hydration-induced reactivation of spent Ca-based sorbents and attrition by impact loading. The sorbent used in this work (a high-calcium Italian limestone) was pre-processed (sulphation at 850{sup o}C in a lab-scale FB, water hydration for 3 h at 25{sup o}C in a thermostatic bath, steam hydration for 3 h at 250 degrees C in a tubular reactor, dehydration at 850{sup o}C in the FB) and subjected to impact tests in a purposely designed impact test rig, operated with particle impact velocities ranging from 4 to 45 m s{sup -1}. The particle size distribution of the debris was worked out to define a fragmentation index and a probability density function of the size of generated fragments. The effect of hydration/reactivation of spent sorbent on propensity to undergo impact fragmentation was assessed, and results are discussed in the light of a mechanistic framework. It was observed that the prevailing particle breakage pattern was splitting/chipping for water-reactivated samples, disintegration for steam-reactivated samples. Characterization of sorbent microstructure by porosimetry and microscopic investigation on the reactivated samples highlighted a clear relationship between the extent of fragmentation and the cumulative specific volume of mesopores.

  20. Microporous-mesoporous carbons for energy storage synthesized by activation of carbonaceous material by zinc chloride, potassium hydroxide or mixture of them

    Härmas, M.; Thomberg, T.; Kurig, H.; Romann, T.; Jänes, A.; Lust, E.

    2016-09-01

    Various electrochemical methods have been applied to establish the electrochemical characteristics of the electrical double layer capacitor (EDLC) consisting of the 1 M triethylmethylammonium tetrafluoroborate solution in acetonitrile and activated carbon based electrodes. Activated microporous carbon materials used for the preparation of electrodes have been synthesized from the hydrothermal carbonization product (HTC) prepared via hydrothermal carbonization process of D-(+)-glucose solution in H2O, followed by activation with ZnCl2, KOH or their mixture. Highest porosity and Brunauer-Emmett-Teller specific surface area (SBET = 2150 m2 g-1), micropore surface area (Smicro = 2140 m2 g-1) and total pore volume (Vtot = 1.01 cm3 g-1) have been achieved for HTC activated using KOH with a mass ratio of 1:4 at 700 °C. The correlations between SBET, Smicro, Vtot and electrochemical characteristics have been studied to investigate the reasons for strong dependence of electrochemical characteristics on the synthesis conditions of carbon materials studied. Wide region of ideal polarizability (ΔV ≤ 3.0 V), very short characteristic relaxation time (0.66 s), and high specific series capacitance (134 F g-1) have been calculated for the mentioned activated carbon material, demonstrating that this system can be used for completing the EDLC with high energy- and power densities.

  1. Synthesis, characterization, and application of surface-functionalized ordered mesoporous nanoparticles

    Chung, Po-Wen [Iowa State Univ., Ames, IA (United States)

    2009-01-01

    The dissertation begins with Chapter 1, which is a general introduction of the fundamental synthesis of mesoporous silica materials, the selective functionlization of mesoporous silica materials, and the synthesis of nanostructured porous materials via nanocasting. In Chapter 2, the thermo-responsive polymer coated mesoporous silica nanoparticles (MSN) was synthesized via surface-initated polymerization and exhibited unique partition activities in a biphasic solution with the thermally induced change. In Chapter 3, the monodispersed spherical MSN with different mesoporous structure (MCM-48) was developed and employed as a template for the synthesis of mesoporous carbon nanoparticles (MCN) via nanocasting. MCN was demonstrated for the delivery of membrane impermeable chemical agents inside the cells. The cellular uptake efficiency and biocompabtibility of MCN with human cervical cancer cells were also investigated. In addition to the biocompabtibility of MCN, MCN was demonstrated to support Rh-Mn nanoparticles for catalytic reaction in Chapter 4. Owing to the unique mesoporosity, Rh-Mn nanoparticles can be well distributed inside the mesoporous structure and exhibited interesting catalytic performance on CO hydrogenation. In Chapter 5, the synthesis route of the aforementioned MCM-48 MSN was discussed and investigated in details and other metal oxide nanoparticles were also developed via nanocasting by using MCM-48 MSN as a template. At last, there is a general conclusion summarized in Chapter 6.

  2. Concentration and immobilization of 137Cs from liquid radioactive waste using sorbents based on hydrated titanium and zirconium oxides

    Voronina, A. V.; Noskova, A. Y.; Gritskevich, E. Y.; Mashkovtsev, M. A.; Semenishchev, V. S.

    2017-09-01

    The possibility of use of sorbents based on hydrated titanium and zirconium oxides (T-3A, T-35, NPF-HTD) for concentration and immobilization of 137Cs from liquid radioactive waste of various chemical composition (fresh water, seawater, solutions containing NaNO3, ammonium acetate, EDTA) was evaluated. It was shown that the NPF-HTD and T-35 sorbents separate 137Cs from fresh water and seawater with distribution coefficients as high as 6.2.104 and 6.1.104, 4.0.105 and 1.6.105 L kg-1 respectively; in 1 M ammonium acetate these values were 2.0.103 and 1.0.103 L kg-1. The NPF-HTD sorbent showed the highest selectivity for cesium in NaNO3 solution: cesium distribution coefficients in 1M NaNO3 was 1.4.106 L kg-1. All studied sorbents are suitable for deactivation of solutions containing EDTA. Cesium distribution coefficients were around 102-103 L kg-1 depending on EDTA concentration. Chemical stability of the sorbents was also studied. It was shown that 137Cs leaching rate from all sorbents meet the requirements for matrix materials.

  3. Structurally stabilized organosilane-templated thermostable mesoporous titania.

    Amoli, Vipin; Tiwari, Rashmi; Dutta, Arghya; Bhaumik, Asim; Sinha, Anil Kumar

    2014-01-13

    Structurally thermostable mesoporous anatase TiO2 (m-TiO2) nanoparticles, uniquely decorated with atomically dispersed SiO2, is reported for the first time. The inorganic Si portion of the novel organosilane template, used as a mesopores-directing agent, is found to be incorporated in the pore walls of the titania aggregates, mainly as isolated sites. This is evident by transmission electron microscopy and high-angle annular dark field scanning transmission electron microscopy, combined with electron dispersive X-ray spectroscopy. This type of unique structure provides exceptional stability to this new material against thermal collapse of the mesoporous structure, which is reflected in its high surface area (the highest known for anatase titania), even after high-temperature (550 °C) calcination. Control of crystallite size, pore diameter, and surface area is achieved by varying the molar ratios of the titanium precursor and the template during synthesis. These mesoporous materials retain their porosity and high surface area after template removal and further NaOH/HCl treatment to remove silica. We investigate their performance for dye-sensitized solar cells (DSSCs) with bilayer TiO2 electrodes, which are prepared by applying a coating of m-TiO2 onto a commercial titania (P25) film. The high surface area of the upper mesoporous layer in the P25-m-TiO2 DSSC significantly increases the dye loading ability of the photoanode. The photocurrent and fill factor for the DSSC with the bilayer TiO2 electrode are greatly improved. The large increase in photocurrent current (ca. 56%) in the P25-m-TiO2 DSSC is believed to play a significant role in achieving a remarkable increase in the photovoltaic efficiency (60%) of the device, compared to DSSCs with a monolayer of P25 as the electrode. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Hierarchical activated mesoporous phenolic-resin-based carbons for supercapacitors.

    Wang, Zhao; Zhou, Min; Chen, Hao; Jiang, Jingui; Guan, Shiyou

    2014-10-01

    A series of hierarchical activated mesoporous carbons (AMCs) were prepared by the activation of highly ordered, body-centered cubic mesoporous phenolic-resin-based carbon with KOH. The effect of the KOH/carbon-weight ratio on the textural properties and capacitive performance of the AMCs was investigated in detail. An AMC prepared with a KOH/carbon-weight ratio of 6:1 possessed the largest specific surface area (1118 m(2) g(-1)), with retention of the ordered mesoporous structure, and exhibited the highest specific capacitance of 260 F g(-1) at a current density of 0.1 A g(-1) in 1 M H2 SO4 aqueous electrolyte. This material also showed excellent rate capability (163 F g(-1) retained at 20 A g(-1)) and good long-term electrochemical stability. This superior capacitive performance could be attributed to a large specific surface area and an optimized micro-mesopore structure, which not only increased the effective specific surface area for charge storage but also provided a favorable pathway for efficient ion transport. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Production of ultra-low-sulfur gasoline: an equilibrium and kinetic analysis on adsorption of sulfur compounds over Ni/MMS sorbents.

    Subhan, Fazle; Liu, B S; Zhang, Q L; Wang, W S

    2012-11-15

    High performance nickel-based micro-mesoporous silica (Ni/MMS) sorbent was prepared by incipient wetness impregnation with ultrasonic aid (IWI-u) for adsorptive desulfurization (ADS) of commercial gasoline and simulated fuels. The sorbents were characterized with BET, XRD, TPR, SEM, HRTEM and TG/DTG. These results show that 20 wt%Ni/MMS (IWI-u) can still retain the framework of MMS and nickel particles were homogeneously distributed in the MMS channels without any aggregation, which improved significantly the ADS performance of the sorbents. The studies on the ADS kinetics indicate that the adsorption behavior of thiophene (T), benzothiophene (BT) and dibenzothiophene (DBT) over 20 wt%Ni/MMS (IWI-u) can be described appropriately by pseudo second-order kinetic model. The intraparticle diffusion model verified that the steric hindrance and intraparticle diffusion were the rate controlling step of the adsorption process of DBT molecules. Langmuir model can be used to describe the adsorption isotherms for T, BT and DBT due to low coverage. The regeneration sorbent maintains the sulfur removal efficiency of 85.9% for 6 cycles. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Enhanced capture of elemental mercury by bamboo-based sorbents

    Tan, Zengqiang; Xiang, Jun; Su, Sheng; Zeng, Hancai; Zhou, Changsong; Sun, Lushi; Hu, Song; Qiu, Jianrong

    2012-01-01

    Highlights: ► The KI-modified BC has excellent capacity for elemental mercury removal. ► The chemisorption plays a dominant role for the modified BC materials. ► The BC-I has strong anti-poisoning ability with the presence of NO or SO 2 . - Abstract: To develop cost-effective sorbent for gas-phase elemental mercury removal, the bamboo charcoal (BC) produced from renewable bamboo and KI modified BC (BC-I) were used for elemental mercury removal. The effect of NO, SO 2 on gas-phase Hg 0 adsorption by KI modified BC was evaluated on a fixed bed reactor using an online mercury analyzer. BET surface area analysis, temperature programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS) were used to determine the pore structure and surface chemistry of the sorbents. The results show that KI impregnation reduced the sorbents’ BET surface area and total pore volume compared with that of the original BC. But the BC-I has excellent adsorption capacity for elemental mercury at a relatively higher temperature of 140 °C and 180 °C. The presence of NO or SO 2 could inhibit Hg 0 capture, but BC-I has strong anti-poisoning ability. The specific reaction mechanism has been further analyzed.

  7. Layer-by-Layer Motif Architectures: Programmed Electrochemical Syntheses of Multilayer Mesoporous Metallic Films with Uniformly Sized Pores.

    Jiang, Bo; Li, Cuiling; Qian, Huayu; Hossain, Md Shahriar A; Malgras, Victor; Yamauchi, Yusuke

    2017-06-26

    Although multilayer films have been extensively reported, most compositions have been limited to non-catalytically active materials (e.g. polymers, proteins, lipids, or nucleic acids). Herein, we report the preparation of binder-free multilayer metallic mesoporous films with sufficient accessibility for high electrocatalytic activity by using a programmed electrochemical strategy. By precisely tuning the deposition potential and duration, multilayer mesoporous architectures consisting of alternating mesoporous Pd layers and mesoporous PdPt layers with controlled layer thicknesses can be synthesized within a single electrolyte, containing polymeric micelles as soft templates. This novel architecture, combining the advantages of bimetallic alloys, multilayer architectures, and mesoporous structures, exhibits high electrocatalytic activity for both the methanol oxidation reaction (MOR) and the ethanol oxidation reaction (EOR). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Aspirin degradation in surface-charged TEMPO-oxidized mesoporous crystalline nanocellulose.

    Carlsson, Daniel O; Hua, Kai; Forsgren, Johan; Mihranyan, Albert

    2014-01-30

    TEMPO-mediated surface oxidation of mesoporous highly crystalline Cladophora cellulose was used to introduce negative surface charges onto cellulose nanofibrils without significantly altering other structural characteristics. This enabled the investigation of the influence of mesoporous nanocellulose surface charges on aspirin chemical stability to be conducted. The negative surface charges (carboxylate content 0.44±0.01 mmol/g) introduced on the mesoporous crystalline nanocellulose significantly accelerated aspirin degradation, compared to the starting material which had significantly less surface charge (0.06±0.01 mmol/g). This effect followed from an increased aspirin amorphisation ability in mesopores of the oxidized nanocellulose. These results highlight the importance of surface charges in formulating nanocellulose for drug delivery. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Poly(ethyleneimine) infused and functionalized Torlon®-silica hollow fiber sorbents for post-combustion CO2 capture

    Li, Fuyue Stephanie

    2014-03-01

    Organic-inorganic hybrid materials functionalized with amine-containing reagents are emerging as an important class of materials for capturing carbon dioxide from flue gas. Polymeric silica hollow fiber sorbents are fabricated through the proven dry-jet/wet-quench spinning process. In our study, a new technique for functionalizing polymeric silica hollow fiber sorbents with poly(ethyleneimine), followed by a post-spinning infusion step was studied. This two step process introduces a sufficient amount of poly(ethyleneimine) to the polymeric silica hybrid material support to improve the CO2 sorption capacity due to the added amine groups. The poly(ethyleneimine) infused and functionalized hollow fiber sorbents are also characterized by a thermal gravimetric analyzer (TGA) to assess their CO2 sorption capacities. © 2014 Elsevier Ltd. All rights reserved.

  10. Synthesis of mesoporous TiO2 in aqueous alcoholic medium and evaluation of its photocatalytic activity

    Kumaresan, L.; Prabhu, A.; Palanichamy, M.; Murugesan, V.

    2011-01-01

    Research highlights: → Mesoporous TiO 2 synthesized using P123 as soft template in sol-gel method. → Nanoparticle aggregates are better for photocatalytic activity than free nanoparticles. → Particle to particle transport of electrons in the conduction band of aggregates are important factor. - Abstract: Mesoporous TiO 2 was synthesized using triblock copolymer as the structure directing template in ethanol/water, isopropanol/water or 1-butanol/water medium by sol-gel method. The presence of intense peak at low angle in the XRD patterns confirmed the orderly arrangement of mesopores in the material. Among the three different alcohols, ethanol had influenced better in controlling the particle size than others. The enhanced specific surface area also revealed the formation of mesopores. Aggregates of particles were clearly seen in the TEM images and the size of the particles was approximately 10 nm. The photocatalytic activity of mesoporous TiO 2 was evaluated using aqueous alachlor as a model pollutant. The activity of mesoporous TiO 2 synthesized in ethanol/water mole ratio of 50 was higher than other mesoporous TiO 2 and commercial TiO 2 (Degussa P-25). The transport of excited electrons from one particle to its neighboring nanoparticles of mesoporous TiO 2 is suggested to be the cause for enhanced photocatalytic activity.

  11. The solid-liquid extraction separation of lithium isotopes by porous composite materials doped with ionic liquids and 2,2'-binaphthyldiyl-17-crown-5

    Xiao-Li Sun; Ling Gu; Dan Qiu; Dong-Hong Ren; Zaijun Li; Zhi-Guo Gu; Jiangnan University, Wuxi

    2015-01-01

    A green and efficient solid-liquid extraction method of lithium isotopes separation by porous composite materials doped with imidazolium ionic liquids and 2,2'-binaphthyldiyl-17-crown-5 has been reported in this paper. The composite materials of mesoporous silica and impregnated resin were synthesized by sol-gel and direct impregnation process, respectively. Various extraction parameters such as the concentration of lithium salt, anion of lithium salt, initial pH, time and temperature were investigated. Under optimized conditions, the maximum single-stage separation factor of 6 Li/ 7 Li was 1.048 ± 0.002, the maximum extraction efficiency was 15.86 %. The sorbents can be regenerated easily with HCl solution and reused repeatedly. (author)

  12. Mesoporous block-copolymer nanospheres prepared by selective swelling.

    Mei, Shilin; Jin, Zhaoxia

    2013-01-28

    Block-copolymer (BCP) nanospheres with hierarchical inner structure are of great interest and importance due to their possible applications in nanotechnology and biomedical engineering. Mesoporous BCP nanospheres with multilayered inner channels are considered as potential drug-delivery systems and templates for multifunctional nanomaterials. Selective swelling is a facile pore-making strategy for BCP materials. Herein, the selective swelling-induced reconstruction of BCP nanospheres is reported. Two poly(styrene-block-2-vinylpyridine) (PS-b-P2VP) samples with different compositions (PS(23600)-b-P2VP(10400) and PS(27700)-b-P2VP(4300)) are used as model systems. The swelling reconstruction of PS-b-P2VP in ethanol, 1-pyrenebutyric acid (PBA)/ethanol, or HCl/ethanol (pH = 2.61) is characterized by scanning electron microscopy and transmission electron microscopy. It is observed that the length of the swellable block in BCP is a critical factor in determining the behavior and nanostructures of mesoporous BCP nanospheres in selective swelling. Moreover, it is demonstrated that the addition of PBA modifies the swelling structure of PS(23600)-b-P2VP(10400) through the interaction between PBA and P2VP blocks, which results in BCP nanospheres with patterned pores of controllable size. The patterned pores can be reversibly closed by annealing the mesoporous BCP nanospheres in different selective solvents. The controllable and reversible open/closed reconstruction of BCP nanospheres can be used to enclose functional nanoparticles or drugs inside the nanospheres. These mesoporous BCP nanospheres are further decorated with gold nanoparticles by UV photoreduction. The enlarged decoration area in mesoporous BCP nanospheres will enhance their activity and sensitivity as a catalyst and electrochemical sensor. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Innovative Route to Prepare of Au/C Catalysts by Replication of Gold-containing Mesoporous Silicas

    Kerdi, Fatmé ; Caps, Valerie; Tuel, Alain

    2011-01-01

    precursor and the composite material is heated at 900 °C under vacuum or nitrogen. Silica is then removed by acid leaching, leading to partially encapsulated gold particles in mesoporous carbon. Carbon prevents aggregation of gold particles at high

  14. Preparation of mesoporous silica films SBA-15 over different substrates

    Campos, V.O.; Sousa, E.M.B. de; Macedo, W.A.A.

    2010-01-01

    Mesoporous materials have been target of frequent interest due to its wide application possibilities, for example development of gas sensors, catalysis, molecules transportation, pharmaceuticals release, synthesis of auto-organized nanostructures, among others. The possibilities of application are enhanced when such materials are disposed in the form of thin and ultrathin films. In this work the preparation of mesoporous SBA-15 silica films is explored by means of the dipcoating technique of a sol-gel on different substrates (glass slides, stainless steel, copper), using the surfactant poly(ethylene glycol)-block-poly(propylene glycol)- block-poly(ethylene glycol), known as P123, a block copolymer. Synthesis parameters surfactant concentration, aging time and temperature were investigated. In this work we present the morphological and structural characterization of the prepared films, which were obtained using atomic force microscopy and x-ray fluorescence and diffraction. (author)

  15. Designing advanced functional periodic mesoporous organosilicas for biomedical applications

    Dolores Esquivel

    2014-03-01

    Full Text Available Periodic mesoporous organosilicas (PMOs, reported for the first time in 1999, constitute a new branch of organic-inorganic hybrid materials with high-ordered structures, uniform pore size and homogenous distribution of organic bridges into a silica framework. Unlike conventional mesoporous silicas, these materials offer the possibility to adjust the surface (hydrophilicity/hydrophobicity and physical properties (morphology, porosity as well as their mechanical stability through the incorporation of different functional organic moieties in their pore walls. A broad variety of PMOs has been designed for their subsequent application in many fields. More recently, PMOs have attracted growing interest in emerging areas as biology and biomedicine. This review provides a comprehensive overview of the most recent breakthroughs achieved for PMOs in biological and biomedical applications.

  16. Adsorption of Ammonia on Regenerable Carbon Sorbents

    Wójtowicz, Marek A.; Cosgrove, Jesph E.; Serio, Michael A..; Wilburn, Monique

    2015-01-01

    Results are presented on the development of reversible sorbents for the combined carbon dioxide, moisture, and trace-contaminant (TC) removal for use in Extravehicular Activities (EVAs), and more specifically in the Primary Life Support System (PLSS). The currently available life support systems use separate units for carbon dioxide, trace contaminants, and moisture control, and the long-term objective is to replace the above three modules with a single one. Data on sorption and desorption of ammonia, which is a major TC of concern, are presented in this paper. The current TC-control technology involves the use of a packed bed of acid-impregnated granular charcoal, which is non-regenerable, and the carbon-based sorbent under development in this project can be regenerated by exposure to vacuum at room temperature. In this study, several carbon sorbents were fabricated and tested for ammonia sorption. Ammonia-sorption capacity was related to carbon pore structure characteristics, and the temperature of oxidative carbon-surface treatment was optimized for enhanced ammonia-sorption performance.

  17. Sorbents based on carbonized rice peel

    Mansurova, R. M.; Taipova, R. A.; Zhylybaeva, N. K.; Mansurov, Z. A.; Bijsenbaev, M. A.

    2004-01-01

    The process receiving of sorbents based on carbonized rice peel (RP) was received and their sorption properties were investigated. Processing carbonization of samples leading on station, this was developed in laboratory of hybrid technology. Carbonization of samples was realized in nitric atmosphere on 400-8000 deg. C. On raising temperature of carbonization content of carbon in samples is rice, hydrogen and oxygen is reduce as a result isolation of volatility products is discover. The samples carbonized on 650 deg. C (910 m 2 /g) owners with maximum removed surface is discover. On carbonization temperature 600-800 deh. C the sorption of ions, which carbonized by sorbents based on rice peel is run to 95-100 %. Electron-microscopic investigation of samples leaded on EM-125 mechanism by accelerating pressure 100 kV. From electron-microscopic print of original samples of RP it is evident, that sample consists of carbonic fractions of different species: carbonic fiber of rounded fractions, fractions of ellipsoid form and of more thickly carbonic structure. Increasing sizes of pores and modification structure of synthesized sorbent is occur during carbonization process. The RP-samples, which carbonized by 650 deg. C has the higher specific surface. Samples consist of thin carbonic scum and reducing specific surface, by higher temperature

  18. Bioactive SrO-SiO2 glass with well-ordered mesopores: characterization, physiochemistry and biological properties.

    Wu, Chengtie; Fan, Wei; Gelinsky, Michael; Xiao, Yin; Simon, Paul; Schulze, Renate; Doert, Thomas; Luo, Yongxiang; Cuniberti, Gianaurelio

    2011-04-01

    For a biomaterial to be considered suitable for bone repair it should ideally be both bioactive and have a capacity for controllable drug delivery; as such, mesoporous SiO(2) glass has been proposed as a new class of bone regeneration material by virtue of its high drug-loading ability and generally good biocompatibility. It does, however, have less than optimum bioactivity and controllable drug delivery properties. In this study, we incorporated strontium (Sr) into mesoporous SiO(2) in an effort to develop a bioactive mesoporous SrO-SiO(2) (Sr-Si) glass with the capacity to deliver Sr(2+) ions, as well as a drug, at a controlled rate, thereby producing a material better suited for bone repair. The effects of Sr(2+) on the structure, physiochemistry, drug delivery and biological properties of mesoporous Sr-Si glass were investigated. The prepared mesoporous Sr-Si glass was found to have an excellent release profile of bioactive Sr(2+) ions and dexamethasone, and the incorporation of Sr(2+) improved structural properties, such as mesopore size, pore volume and specific surface area, as well as rate of dissolution and protein adsorption. The mesoporous Sr-Si glass had no cytotoxic effects and its release of Sr(2+) and SiO(4)(4-) ions enhanced alkaline phosphatase activity - a marker of osteogenic cell differentiation - in human bone mesenchymal stem cells. Mesoporous Sr-Si glasses can be prepared to porous scaffolds which show a more sustained drug release. This study suggests that incorporating Sr(2+) into mesoporous SiO(2) glass produces a material with a more optimal drug delivery profile coupled with improved bioactivity, making it an excellent material for bone repair applications. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  19. Phosphorus removal from aqueous solution using iron coated natural and engineered sorbents

    Boujelben, N.; Bouzid, J.; Elouear, Z.; Feki, M.; Jamoussi, F.; Montiel, A.

    2008-01-01

    New filtration materials covered with metallic oxides are good adsorbents for both cation and anion forms of pollutants. Sfax is one of the most important industrial towns in Tunisia. Its phosphate manufacture in particular is causing considerable amounts of water pollution. Therefore, there is a need to find out a new way of getting rid of this excessive phosphate from water. This work is aimed to examining the potential of three sorbent materials (synthetic iron oxide coated sand (SCS), naturally iron oxide coated sand (NCS) and iron oxide coated crushed brick (CB)) for removing phosphate ions from aqueous solutions. According to our literature survey CB was not used as adsorbent previously. Phosphate ions are used here as species model for the elimination of other similar pollutants (arsenates, antimonates). Optical microscope and scanning electron microscope (SEM) analyses were used to investigate the surface properties and morphology of the coated sorbents. Infra-red spectroscopy and X-ray diffraction techniques were also used to characterize the sorbent structures. Results showed that iron coated crushed brick possess more micro pores and a higher surface area owing to its clay nature. The comparative sorption of PO 4 3- from aqueous solutions by SCS, CB and NCS was investigated by batch experiments. The estimated optimum pH of phosphate ion retention for the considered sorbents was 5. The equilibrium data were analysed using the Langmuir and Freundlich isotherms. The sorption capacities of PO 4 3- at pH 5 were 1.5 mg/g for SCS, 1.8 mg/g for CB and 0.88 mg/g for NCS. The effect of temperature on sorption phenomenon was also investigated. The results indicated that adsorption is an endothermic process for phosphate ions removal. This study demonstrates that all the considered sorbents can be used as an alternative emerging technology for water treatment without any side effect or treatment process alteration

  20. Functionalized Organosilicate Sorbents for Air Purification

    2013-12-23

    Average mesopore diameters are similar to E50 (81 Å). There is a significant reduction in the pore diameter distribution near the micropore range...capacity. This tends to indicate bulk and internal diffusion limitations. Under humid conditions the phenomenon is exacerbated; breakthrough occurs more...One possibility is that octane sorption is limited by internal pore diffusion rates resulting from condensation in smaller pores first which may

  1. Advanced sorbent development progam; development of sorbents for moving-bed and fluidized-bed applications

    Ayala, R.E.; Venkataramani, V.S.

    1998-01-01

    The integrated gasification combined cycle (IGCC) power system using high-temperature coal gas cleanup is one of the most promising advanced technologies for the production of electric power from coal in an environmentally acceptable manner. Unlike conventional low-temperature cleanup systems that require costly heat exchangers, high-temperature coal gas cleanup systems can be operated near 482-538 C (900-1000F) or higher, conditions that are a closer match with the gasifier and turbine components in the IGCC system, thus resulting is a more efficient overall system. GE is developing a moving-bed, high-temperature desulfurization system for the IGCC power cycle in which zinc-based regenerable sorbents are currently being used as desulfurization sorbents. Zinc titanate and other proprietary zinc-based oxides are being considered as sorbents for use in the Clean Coal Technology Demonstration Program at Tampa Electric Co.s (TECo) Polk Power Station. Under cold startup conditions at TECo, desulfurization and regeneration may be carried out at temperatures as low as 343 C (650 F), hence a versatile sorbent is desirable to perform over this wide temperature range. A key to success in the development of high-temperature desulfurization systems is the matching of sorbent properties for the selected process operating conditions, namely, sustainable desulfurization kinetics, high sulfur capacity, and mechanical durability over multiple cycles. Additionally, the sulfur species produced during regeneration of the sorbent must be in a form compatible with sulfur recovery systems, such as sulfuric acid or elemental sulfur processes. The overall objective of this program is to develop regenerable sorbents for hydrogen sulfide removal from coal-derived fuel gases in the temperature range 343-538 C (650-1000 F). Two categories of reactor configurations are being considered: moving-bed reactors and fluidized-bed (bubbling and circulating) reactors. In addition, a cost assessment and

  2. High temperature capture of CO2 on lithium-based sorbents from rice husk ash.

    Wang, Ke; Guo, Xin; Zhao, Pengfei; Wang, Fanzi; Zheng, Chuguang

    2011-05-15

    Highly efficient Li(4)SiO(4) (lithium orthosilicate)-based sorbents for CO(2) capture at high temperature, was developed using waste materials (rice husk ash). Two treated rice husk ash (RHA) samples (RHA1 and RHA2) were prepared and calcined at 800°C in the presence of Li(2)CO(3). Pure Li(4)SiO(4) and RHA-based sorbents were characterized by X-ray fluorescence, X-ray diffraction, scanning electron microscopy, nitrogen adsorption, and thermogravimetry. CO(2) sorption was tested through 15 carbonation/calcination cycles in a fixed bed reactor. The metals of RHA were doped with Li(4)SiO(4) resulting to inhibited growth of the particles and increased pore volume and surface area. Thermal analyses indicated a much better CO(2) absorption in Li(4)SiO(4)-based sorbent prepared from RHA1 (higher metal content sample) because the activation energies for the chemisorption process and diffusion process were smaller than that of pure Li(4)SiO(4). RHA1-based sorbent also maintained higher capacities during the multiple cycles. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Recovery of Lithium from Geothermal Brine with Lithium-Aluminum Layered Double Hydroxide Chloride Sorbents.

    Paranthaman, Mariappan Parans; Li, Ling; Luo, Jiaqi; Hoke, Thomas; Ucar, Huseyin; Moyer, Bruce A; Harrison, Stephen

    2017-11-21

    We report a three-stage bench-scale column extraction process to selectively extract lithium chloride from geothermal brine. The goal of this research is to develop materials and processing technologies to improve the economics of lithium extraction and production from naturally occurring geothermal and other brines for energy storage applications. A novel sorbent, lithium aluminum layered double hydroxide chloride (LDH), is synthesized and characterized with X-ray powder diffraction, scanning electron microscopy, inductively coupled plasma optical emission spectrometry (ICP-OES), and thermogravimetric analysis. Each cycle of the column extraction process consists of three steps: (1) loading the sorbent with lithium chloride from brine; (2) intermediate washing to remove unwanted ions; (3) final washing for unloading the lithium chloride ions. Our experimental analysis of eluate vs feed concentrations of Li and competing ions demonstrates that our optimized sorbents can achieve a recovery efficiency of ∼91% and possess excellent Li apparent selectivity of 47.8 compared to Na ions and 212 compared to K ions, respectively in the brine. The present work demonstrates that LDH is an effective sorbent for selective extraction of lithium from brines, thus offering the possibility of effective application of lithium salts in lithium-ion batteries leading to a fundamental shift in the lithium supply chain.

  4. Multifunctional EuYVO{sub 4} nanoparticles coated with mesoporous silica

    Justino, Larissa G. [Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901 Ribeirão Preto, SP (Brazil); Nigoghossian, Karina [Inst. of Chemistry – São Paulo State University- UNESP, 14801-970 Araraquara, SP (Brazil); Capote, Ticiana S.O.; Scarel-Caminaga, Raquel M. [Department of Morphology, Dental School at Araraquara, Univ. Estadual Paulista – UNESP, Araraquara, SP (Brazil); Ribeiro, Sidney J.L. [Inst. of Chemistry – São Paulo State University- UNESP, 14801-970 Araraquara, SP (Brazil); Caiut, José Maurício A., E-mail: caiut@ffclrp.usp.br [Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901 Ribeirão Preto, SP (Brazil)

    2016-11-15

    Mesoporous structures are interesting materials for the incorporation of dyes, drugs, and luminescent systems, leading to materials with important multifunctionalities. In a very unique way, these guest/host materials combine the high stability of inorganic systems, new guest-structuring features, and adsorption mechanisms in their well-defined pores. This work evaluates the luminescent properties of rare earth-doped YVO{sub 4} nanoparticles coated with a mesoporous silica shell. The use of two different synthesis methodologies allowed for particle size control. The crystalline phase emerged without further heat treatment. The mesoporous shell decreased undesirable quenching effects on YVO{sub 4}:Eu{sup 3+} nanoparticles and rendered them biocompatible. The materials prepared herein could have interesting applications as luminescent markers or drug release systems.

  5. Ordered mesoporous carbon for electrochemical sensing: A review

    Ndamanisha, Jean Chrysostome [Faculty of Chemistry, Northeast Normal University, Changchun 130024 (China); Universite du Burundi, Institut de pedagogie appliquee, B.P. 5223, Bujumbura (Burundi); Guo Liping, E-mail: guolp078@nenu.edu.cn [Faculty of Chemistry, Northeast Normal University, Changchun 130024 (China)

    2012-10-17

    Highlights: Black-Right-Pointing-Pointer The preparation and functionalization of ordered mesoporous carbon. Black-Right-Pointing-Pointer Their applications as electrochemical sensors with high electrocatalytic activity. Black-Right-Pointing-Pointer A promising electrode material based on its interesting properties. - Abstract: With its well-ordered pore structure, high specific surface area and tunable pore diameters in the mesopore range, ordered mesoporous carbon (OMC) is suitable for applications in catalysis and sensing. We report recent applications of OMC in electrochemical sensors and biosensors. After a brief description of the electrochemical properties, the functionalization of the OMC for improvement of the electrocatalytic properties is then presented. We show how the ordered mesostructure of OMC is very important in those applications. The high density of edge plane-like defective sites (EDSs), oxygen-containing groups and a large surface area on OMC may provide many favorable sites for electron transfer to compounds, which makes OMC a potential novel material for an investigation of the electrochemical behavior of substances. Moreover, the structural capabilities of OMC at the scale of a few nanometers agree with immobilization of other electrocataytic substances. Interesting properties of this material may open up a new approach to study the electrochemical determination of other biomolecules.

  6. Cationic polymers and porous materials

    Han, Yu

    2017-04-27

    According to one or more embodiments, cationic polymers may be produced which include one or more monomers containing cations. Such cationic polymers may be utilized as structure directing agents to form mesoporous zeolites. The mesoporous zeolites may include micropores as well as mesopores, and may have a surface area of greater than 350 m2/g and a pore volume of greater than 0.3 cm3/g. Also described are core/shell zeolites, where at least the shell portion includes a mesoporous zeolite material.

  7. Cationic polymers and porous materials

    Han, Yu; Tian, Qiwei; Dong, Xinglong; Liu, Zhaohui; Basset, Jean-Marie; Saih, Youssef; Sun, Miao; Xu, Wei; Shaikh, Sohel

    2017-01-01

    According to one or more embodiments, cationic polymers may be produced which include one or more monomers containing cations. Such cationic polymers may be utilized as structure directing agents to form mesoporous zeolites. The mesoporous zeolites may include micropores as well as mesopores, and may have a surface area of greater than 350 m2/g and a pore volume of greater than 0.3 cm3/g. Also described are core/shell zeolites, where at least the shell portion includes a mesoporous zeolite material.

  8. In situ synthesis of N and Cu functionalized mesoporous FDU-14 resins and carbons for electrochemical hydrogen storage

    Kong, AiGuo; Wang, WenJuan; Yang, Fan; Ding, HanMing; Shan, YongKui [Department of Chemistry, East China Normal University, ShangHai 200062 (China)

    2010-07-15

    N and Cu cooperatively functionalized mesoporous resin and carbon materials with bicontinuous cubic structure (FDU-14) were obtained by a novel synthesis method. In this method, block copolymers were used as the templates as well as the precursors for the preparation of these modifying mesoporous materials. The CuC{sub 2}O{sub 4} in the channels of mesoporous FDU-14 resins was gotten by in situ oxidation of the templates in a catalytic redox system containing Cu{sup 2+}, Al{sup 3+}, NO{sub 3}{sup -}, PO{sub 4}{sup 3-}, SO{sub 4}{sup 2-} ions. Simultaneously, the phenol-formaldehyde resin frameworks were in situ functionalized by the amine group resulting from the reduction of NO{sub 3}{sup -}, leading to the formation of N and CuC{sub 2}O{sub 4} modified mesoporous FDU-14 resin materials. Its pyrolysis at the different temperatures resulted in the production of N and Cu cooperatively functionalized mesoporous FDU-14 resin and carbon materials. The structure and composition of these materials were characterized by the X-ray power diffraction, transmission electron microscopy, N{sub 2} adsorption-desorption analysis, X-ray photoelectron spectroscopy, infrared spectroscopy, thermogravimetry analysis, and inductive coupled plasma emission spectroscopy. The electrochemical measurement indicated that N and Cu cooperatively functionalized mesoporous FDU-14 carbon materials possessed the enhanced electrochemical hydrogen storage performance. (author)

  9. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

    Jha, M.C.; Berggren, M.H.

    1989-05-02

    AMAX Research Development Center (AMAX R D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  10. Properties and reactivity of reactivated calcium-based sorbents

    Davini, P. [Pisa University, Pisa (Italy). Dept. of Chemical Engineering

    2002-04-01

    Calcium-based sorbents used in the process of high temperature desulfurisation of flue gases are partly regenerable by hydration with steam; the best results are obtained for treatment temperatures of approximately 300{degree}C. The regeneration process, and the consequent increase in the sorbent consumption can be correlated to the surface characteristics (BET surface area, porosity and pore size distribution) of the sorbents themselves. In particular, the presence of suitable pore structure, also having pores large enough to let molecules easily penetrate the inner part of the sorbent particles, is very important. 27 refs., 9 figs., 2 tabs.

  11. Application of TIO2 as A sorbent for radioactive waste

    Zamroni, H.; Las, T.; Kamarz, H.

    1997-01-01

    The sorption properties of the neodymium has been studied by using TiO 2 sorbent. The experiment was carried out by batch methods to investigate the kinetic sorption, effect of pH and effect of NaNO 3 concentration in the solution. Neodymium uses for a model of trivalent actinide treated by TiO 2 which was known as materials having high thermal and radiation stabilities as well as potentially used for immobilization of waste with cement or vitrification. the results show that the optimum of kinetic sorption was obtained after one day experiment to reach the equilibrium in sorption on pH 4, and the increasing of NaNO 3 concentrations will increase the sorption of neodymium in solution (author)

  12. Engineering metal (hydr)oxide sorbents for removal of arsenate and similar weak-acid oxyanion contaminants: A critical review with emphasis on factors governing sorption processes.

    Hristovski, Kiril D; Markovski, Jasmina

    2017-11-15

    To create an integrative foundation for engineering of the next generation inexpensive sorbent systems, this critical review addresses the existing knowledge gap in factor/performance relationships between weak-acid oxyanion contaminants and metal (hydr)oxide sorbents. In-depth understanding of fundamental thermodynamics and kinetics mechanisms, material fabrication, and analytical and characterization techniques, is necessary to engineer sorbent that exhibit high capacity, selectivity, stability, durability and mass transport of contaminants under a wide range of operating and water matrix conditions requirements. From the perspective of thermodynamics and kinetics, this critical review examines the factors affecting sorbent performances and analyzes the existing research to elucidate future directions aimed at developing novel sorbents for removal of weak-acid oxyanion contaminants from water. Only sorbents that allow construction of simple and inexpensive water treatment systems adapted to overcome fiscal and technological barriers burdening small communities could pave the road for providing inexpensive potable water to millions of people. Novel sorbents, which exhibit (1) poor performances in realistic operating and water matrix conditions and/or (2) do not comply with the purely driven economics factors of production scalability or cost expectations, are predestined to never be commercialized. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Micelle-Template Synthesis of Nitrogen-Doped Mesoporous Graphene as an Efficient Metal-Free Electrocatalyst for Hydrogen Production

    Huang, Xiaodan; Zhao, Yufei; Ao, Zhimin; Wang, Guoxiu

    2014-12-01

    Synthesis of mesoporous graphene materials by soft-template methods remains a great challenge, owing to the poor self-assembly capability of precursors and the severe agglomeration of graphene nanosheets. Herein, a micelle-template strategy to prepare porous graphene materials with controllable mesopores, high specific surface areas and large pore volumes is reported. By fine-tuning the synthesis parameters, the pore sizes of mesoporous graphene can be rationally controlled. Nitrogen heteroatom doping is found to remarkably render electrocatalytic properties towards hydrogen evolution reactions as a highly efficient metal-free catalyst. The synthesis strategy and the demonstration of highly efficient catalytic effect provide benchmarks for preparing well-defined mesoporous graphene materials for energy production applications.

  14. Functionalized magnetic mesoporous silica nanoparticles for U removal from low and high pH groundwater

    Li, Dien, E-mail: dien.li@srs.gov [Savannah River National Laboratory, Aiken, SC 29808 (United States); Egodawatte, Shani [Department of Chemistry, University of Iowa, Iowa City, IA 52242 (United States); Kaplan, Daniel I. [Savannah River National Laboratory, Aiken, SC 29808 (United States); Larsen, Sarah C. [Department of Chemistry, University of Iowa, Iowa City, IA 52242 (United States); Serkiz, Steven M. [Savannah River National Laboratory, Aiken, SC 29808 (United States); Department of Physics and Astronomy, Clemson University, Clemson, SC 29634 (United States); Seaman, John C. [Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802 (United States)

    2016-11-05

    Highlights: • Magnetic mesoporous silica nanoparticles were functionalized with organic molecules. • The functionalized nanoparticles had high surface areas and consistent pore sizes. • The functionalized nanoparticles were easily separated due to their magnetism. • They exhibited high capacity for uranium removal from low- or high-pH groundwater. - Abstract: U(VI) species display limited adsorption onto sediment minerals and synthetic sorbents in pH <4 or pH >8 groundwater. In this work, magnetic mesoporous silica nanoparticles (MMSNs) with magnetite nanoparticle cores were functionalized with various organic molecules using post-synthetic methods. The functionalized MMSNs were characterized using N{sub 2} adsorption-desorption isotherms, thermogravimetric analysis (TGA), transmission electron microscopy (TEM), {sup 13}C cross polarization and magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectroscopy, and powder X-ray diffraction (XRD), which indicated that mesoporous silica (MCM-41) particles of 100–200 nm formed around a core of magnetic iron oxide, and the functional groups were primarily grafted into the mesopores of ∼3.0 nm in size. The functionalized MMSNs were effective for U removal from pH 3.5 and 9.6 artificial groundwater (AGW). Functionalized MMSNs removed U from the pH 3.5 AGW by as much as 6 orders of magnitude more than unfunctionalized nanoparticles or silica and had adsorption capacities as high as 38 mg/g. They removed U from the pH 9.6 AGW as much as 4 orders of magnitude greater than silica and 2 orders of magnitude greater than the unfunctionalized nanoparticles with adsorption capacities as high as 133 mg/g. These results provide an applied solution for treating U contamination that occurs at extreme pH environments and a scientific foundation for solving critical industrial issues related to environmental stewardship and nuclear power production.

  15. Magnetic ordered mesoporous Fe3O4/CeO2 composites with synergy of adsorption and Fenton catalysis

    Li, Keyan; Zhao, Yongqin; Song, Chunshan; Guo, Xinwen

    2017-12-01

    Magnetic Fe3O4/CeO2 composites with highly ordered mesoporous structure and large surface area were synthesized by impregnation-calcination method, and the mesoporous CeO2 as support was synthesized via the hard template approach. The composition, morphology and physicochemical properties of the materials were characterized by XRD, SEM, TEM, XPS, Raman spectra and N2 adsorption/desorption analysis. The mesoporous Fe3O4/CeO2 composite played a dual-function role as both adsorbent and Fenton-like catalyst for removal of organic dye. The methylene blue (MB) removal efficiency of mesoporous Fe3O4/CeO2 was much higher than that of irregular porous Fe3O4/CeO2. The superior adsorption ability of mesoporous materials was attributed to the abundant oxygen vacancies on the surface of CeO2, high surface area and ordered mesoporous channels. The good oxidative degradation resulted from high Ce3+ content and the synergistic effect between Fe and Ce. The mesoporous Fe3O4/CeO2 composite presented low metal leaching (iron 0.22 mg L-1 and cerium 0.63 mg L-1), which could be ascribed to the strong metal-support interactions for dispersion and stabilization of Fe species. In addition, the composite can be easily separated from reaction solution with an external magnetic field due to its magnetic property, which is important to its practical applications.

  16. Development of a Catalyst/Sorbent for Methane Reforming

    B.H. Shans; T.D. Wheelock; Justinus Satrio; Karl Albrecht; Tanya Harris Janine Keeley; Ben Silva; Aaron Shell; Molly Lohry; Zachary Beversdorf

    2008-12-31

    This project led to the further development of a combined catalyst and sorbent for improving the process technology required for converting CH{sub 4} and/or CO into H{sub 2} while simultaneously separating the CO{sub 2} byproduct all in a single step. The new material is in the form of core-in-shell pellets such that each pellet consists of a CaO core surrounded by an alumina-based shell capable of supporting a Ni catalyst. The Ni is capable of catalyzing the reactions of steam with CH{sub 4} or CO to produce H{sub 2} and CO{sub 2}, whereas the CaO is capable of absorbing the CO{sub 2} as it is produced. The absorption of CO{sub 2} eliminates the reaction inhibiting effects of CO{sub 2} and provides a means for recovering the CO{sub 2} in a useful form. The present work showed that the lifecycle performance of the sorbent can be improved either by incorporating a specific amount of MgO in the material or by calcining CaO derived from limestone at 1100 C for an extended period. It also showed how to prepare a strong shell material with a large surface area required for supporting an active Ni catalyst. The method combines graded particles of {alpha}-alumina with noncrystalline alumina having a large specific surface area together with a strength promoting additive followed by controlled calcination. Two different additives produced good results: 3 {micro}m limestone and lanthanum nitrate which were converted to their respective oxides upon calcination. The oxides partially reacted with the alumina to form aluminates which probably accounted for the strength enhancing properties of the additives. The use of lanthanum made it possible to calcine the shell material at a lower temperature, which was less detrimental to the surface area, but still capable of producing a strong shell. Core-in-shell pellets made with the improved shell materials and impregnated with a Ni catalyst were used for steam reforming CH{sub 4} at different temperatures and pressures. Under all

  17. Molecular simulation of adsorption and transport in hierarchical porous materials.

    Coasne, Benoit; Galarneau, Anne; Gerardin, Corine; Fajula, François; Villemot, François

    2013-06-25

    Adsorption and transport in hierarchical porous solids with micro- (~1 nm) and mesoporosities (>2 nm) are investigated by molecular simulation. Two models of hierarchical solids are considered: microporous materials in which mesopores are carved out (model A) and mesoporous materials in which microporous nanoparticles are inserted (model B). Adsorption isotherms for model A can be described as a linear combination of the adsorption isotherms for pure mesoporous and microporous solids. In contrast, adsorption in model B departs from adsorption in pure microporous and mesoporous solids; the inserted microporous particles act as defects, which help nucleate the liquid phase within the mesopore and shift capillary condensation toward lower pressures. As far as transport under a pressure gradient is concerned, the flux in hierarchical materials consisting of microporous solids in which mesopores are carved out obeys the Navier-Stokes equation so that Darcy's law is verified within the mesopore. Moreover, the flow in such materials is larger than in a single mesopore, due to the transfer between micropores and mesopores. This nonzero velocity at the mesopore surface implies that transport in such hierarchical materials involves slippage at the mesopore surface, although the adsorbate has a strong affinity for the surface. In contrast to model A, flux in model B is smaller than in a single mesopore, as the nanoparticles act as constrictions that hinder transport. By a subtle effect arising from fast transport in the mesopores, the presence of mesopores increases the number of molecules in the microporosity in hierarchical materials and, hence, decreases the flow in the micropores (due to mass conservation). As a result, we do not observe faster diffusion in the micropores of hierarchical materials upon flow but slower diffusion, which increases the contact time between the adsorbate and the surface of the microporosity.

  18. Removal of metals from industrial wastewater and urban runoff by mineral and bio-based sorbents.

    Gogoi, Harshita; Leiviskä, Tiina; Heiderscheidt, Elisangela; Postila, Heini; Tanskanen, Juha

    2018-03-01

    The study was performed to evaluate chemically modified biosorbents, hydrochloric acid treated peat (HCl-P) and citric acid treated sawdust (Citric acid-SD) for their metal removal capacity from dilute industrial wastewater and urban runoff and compare their efficiency with that of commercially available mineral sorbents (AQM PalPower M10 and AQM PalPower T5M5 magnetite). Batch and column experiments were conducted using real water samples to assess the sorbents' metal sorption capacity. AQM PalPower M10 (consisting mainly of magnesium, iron and silicon oxides) exhibited excellent Zn removal from both industrial wastewater and spiked runoff water samples even at low dosages (0.1 g/L and 0.05 g/L, respectively). The high degree of Zn removal was associated with the release of hydroxyl ions from the sorbent and subsequent precipitation of zinc hydroxide. The biosorbents removed Ni and Cr better than AQM PalPower M10 from industrial wastewater and performed well in removing Cr and Cu from spiked runoff water, although at higher dosages (0.3-0.75 g/L). The main mechanism of sorption by biosorbents was ion exchange. The sorbents required a short contact time to reach equilibrium (15-30 min) in both tested water samples. AQM PalPower T5M5 magnetite was the worst performing sorbent, leaching Zn into both industrial and runoff water and Ni into runoff water. Column tests revealed that both HCl-P and AQM PalPower M10 were able to remove metals, although some leaching was witnessed, especially As from AQM PalPower M10. The low hydraulic conductivity observed for HCl-P may restrict the possibilities of using such small particle size peat material in a filter-type passive system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. A Low Cost, High Capacity Regenerable Sorbent for Pre-combustion CO{sub 2} Capture

    Alptekin, Gokhan

    2012-09-30

    The overall objective of the proposed research is to develop a low cost, high capacity CO{sub 2} sorbent and demonstrate its technical and economic viability for pre-combustion CO{sub 2} capture. The specific objectives supporting our research plan were to optimize the chemical structure and physical properties of the sorbent, scale-up its production using high throughput manufacturing equipment and bulk raw materials and then evaluate its performance, first in bench-scale experiments and then in slipstream tests using actual coal-derived synthesis gas. One of the objectives of the laboratory-scale evaluations was to demonstrate the life and durability of the sorbent for over 10,000 cycles and to assess the impact of contaminants (such as sulfur) on its performance. In the field tests, our objective was to demonstrate the operation of the sorbent using actual coal-derived synthesis gas streams generated by air-blown and oxygen-blown commercial and pilot-scale coal gasifiers (the CO{sub 2} partial pressure in these gas streams is significantly different, which directly impacts the operating conditions hence the