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Sample records for mesoporous phenol-formaldehyde resins

  1. Chromatographic zinc isotope separation by phenol formaldehyde benzo crown resin.

    Science.gov (United States)

    Ding, Xingcheng; Nomura, Masao; Suzuki, Tatsuya; Sugiyama, Yuichi; Kaneshiki, Toshitaka; Fujii, Yasuhiko

    2006-04-28

    New types of phenol formaldehyde resin having benzo crown as a functional group were synthesized and applied to zinc isotope chromatographic operation. Zinc adsorption and isotope separation capacities were dramatically improved by using phenol formaldehyde benzo-15-crown-5 resin. Zinc batch adsorption tests were performed by various dehydrated organic solvents. Separation coefficient, epsilon 8.1 x 10(-4) and height equivalent to a theoretical plate (HETP) 0.105 cm for the isotopic pair of 68Zn/64Zn in phenol formaldehyde benzo-15-crown-5 resin were obtained in the case of acetone as the solvent at 298+/-1K.

  2. RELATION BETWEEN MECHANICAL PROPERTIES AND PYROLYSIS TEMPERATURE OF PHENOL FORMALDEHYDE RESIN FOR GAS SEPARATION MEMBRANES

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    MONIKA ŠUPOVÁ

    2012-03-01

    Full Text Available The aim of this paper has been to characterize the relation between the pyrolysis temperature of phenol-formaldehyde resin, the development of a porous structure, and the mechanical properties for the application of semipermeable membranes for gas separation. No previous study has dealt with this problem in its entirety. Phenol-formaldehyde resin showed an increasing trend toward micropore porosity in the temperature range from 500 till 1000°C, together with closure of mesopores and macropores. Samples cured and pyrolyzed at 1000°C pronounced hysteresis of desorption branch. The ultimate bending strength was measured using a four-point arrangement that is more suitable for measuring of brittle materials. The chevron notch technique was used for determination the fracture toughness. The results for mechanical properties indicated that phenol-formaldehyde resin pyrolyzates behaved similarly to ceramic materials. The data obtained for the material can be used for calculating the technical design of gas separation membranes.

  3. Nanoparticles-based phenol-formaldehyde hybrid resins.

    Science.gov (United States)

    Hernández-Padrón, Genoveva; García-Garduño, Margarita; Canseco, Miguel A; Castaño, Victor M

    2008-06-01

    The synthesis, characterization and corrosion properties of a novel material, produced by the reaction of silica nanoparticles with a functionalized Phenol-Formaldehyde Resin (PFR), are presented. Carboxylic groups were attached in situ to the PFR skeleton to produce a functionalized resin (PFR-SA), which is then reacted with sol-gel-prepared silica nanoparticles, yielding a novel hybrid (organic/inorganic) material (PFR-SA-nanoSiO2). This hybrid material was characterized by FT-IR, FT-Raman, TGA, DSC, SEM and corrosion tests, whose results showed significant improvement of the thermal properties in comparison with the PFR coating. In addition, the new material was efficient and durable against corrosion of metals, with the anticorrosive performance of PFR-SA and PFR-SA/nanoSiO2 coating films being superior to those of the original PFR coating.

  4. Preparation of phenol formaldehyde resin from phenolated wood

    Institute of Scientific and Technical Information of China (English)

    LIGai-yun; QINTe-fu; TohmuraShin-ichiro; IkedaAtsushi

    2004-01-01

    The technique for preparing phenol formaldehyde resin from phenolated wood (PWF) and its characters were studied and analyzed. Poplar (Populus spp.) wood meal was liquefied by phenol in the presence of sulfuric acid as a catalyst. After the liquefied products were cooled, alkaline catalyst and formaldehyde were added. The mixture was kept at (60±2)℃ for lh and then was heated to (85±2)℃ for lh. The influence of molar ratio of formaldehyde to phenol (F/P) was investigated. The results showed when the molar ratio of formaldehyde to phenol was over 1.8, the PWF adhesives had high bond quality, bond durability and extremely low aldehydes emissions.

  5. 介孔分子筛/线性酚醛树脂杂化材料的制备及表征%Preparation and Characterization of Mesoporous Silica/ Novolac Type Phenol-Formaldehyde Resin Hybrid Materials

    Institute of Scientific and Technical Information of China (English)

    余传柏; 韦春; 刘红霞; 蒙礼统

    2012-01-01

    Mesoporous silica/novolac type phenol-formaldehyde resin hybrid materials were prepared via in situ polymerization at the silica SBA-15,which was treated with γ-glycidyl oxypropyl trimethoxysilane(KH560) as coupling agent.SBA-15,SBA-15-KH560 and E-SBA-15/PF were characterized and analyzed with X-ray diffraction(XRD),N2 adsorption isotherm,Fourier transform infrared spectroscopic(FT-IR) and thermogravimetric analysis(TGA) respectively.The results indicate that KH560 was chemically grafted onto SBA-15,and PF distributed into the inner and outer path of the SBA-15.An interpenetrating network of organic-inorganic was formed in this hybrid materials.The regular structure of SBA-15 was little influenced with KH560,but it was greatly modified viain situ polymertization.%利用水热法合成介孔分子筛(SBA-15),选择KH560对其表面进行修饰后采用原位聚合的方法制备了介孔分子筛/线性酚醛树脂(SBA-15/PF)有机无机杂化材料。通过傅立叶红外光谱(FT-IR)、X射线衍射(XRD)、N2吸附和热失重分析(TGA)等表征手段对杂化材料的制备过程进行跟踪研究。结果表明,KH-560已嫁接到SBA-15的内外表面,线性酚醛树脂分布于介孔分子筛孔道内外,并与SBA-15存在键接作用,形成有机无机互穿网络结构;表面修饰过程对SBA-15有序结构影响较小,而原位聚合会破坏介孔分子筛部分有序结构。

  6. Study on binder system of CO2-cured phenol-formaldehyde resin used in foundry

    Institute of Scientific and Technical Information of China (English)

    Liu Weihua; Li Yingmin; Qu Xueliang; Liu Xiuling

    2008-01-01

    A new aqueous alkaline resol phenol-formaldehyde resin has been prepared from phenol and formaldehyde using NaOH as catalyst;the optimum synthetic process has been determined.With addition of some cross-linking agents,after passing carbon dioxide gas through the resin bonded sand,high as-gassed strength and 24 h strength are achieved.The bonding bridge of the resin bonded sand fracture has been analyzed by using SEM.

  7. Characterization of Substituted Phenol-Formaldehyde Resins Using Solid-State Carbon-13 NMR

    Science.gov (United States)

    1989-05-22

    cashew nut shell liquid , 3-n-pentadecylphenol and phenol with formaldehyde. The resulting resins were crosslinked and then investigated using...should be sent SYNOPSIS Crosslinked substituted phenol-formaldehyde resins were synthesized from cashew nut shell liquid , 3-n-pentadecylphenol and... nut shell liquid (CNSL) and are the basis for binder resins and friction particles in composite friction materials. CNSL is isolated from cashew nut

  8. Analysis of Pyrolysates for Phenol Formaldehyde Resin by Py-GC/MS

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Pyrolysis of phenol formaldehyde resin has been investigated by Pyrolysis Gas Chromatography- Mass Spectroscopy at the different temperatures from 500℃ to 750℃. Its composition of pyrolysates has been analyzed. Several compounds, especially benzene, toluene, p-xylene could only be formed above 500-550℃. However, peak intensities for some phenol derivatives were decreased at the higher temperature. During pyrolysis,for thermo-setting phenol formaldehyde resins, polymeric chain scissions take place as a successive removal of the monomer units from the polymeric chain. The chain scissions are followed by secondary reactions, which leads to a variety of compounds. Addition reactions can also take place among the double-bond compounds during pyrolysis.

  9. Phenol-Formaldehyde Resin-Based Carbons for CO2 Separation at Sub-Atmospheric Pressures

    OpenAIRE

    2016-01-01

    The challenge of developing effective separation and purification technologies that leave much smaller energy footprints is greater for carbon dioxide (CO2) than for other gases. In addition to its involvement in climate change, CO2 is present as an impurity in biogas and bio-hydrogen (biological production by dark fermentation), in post-combustion processes (flue gas, CO2-N2) and many other gas streams. Selected phenol-formaldehyde resin-based activated carbons prepared in our laboratory hav...

  10. HPLC Characterization of Phenol-Formaldehyde Resole Resin Used in Fabrication of Shuttle Booster Nozzles

    Science.gov (United States)

    Young, Philip R.

    1999-01-01

    A reverse phase High Performance Liquid Chromatographic method was developed to rapidly fingerprint a phenol-formaldehyde resole resin similar to Durite(R) SC-1008. This resin is used in the fabrication of carbon-carbon composite materials from which Space Shuttle Solid Rocket Booster nozzles are manufactured. A knowledge of resin chemistry is essential to successful composite processing and performance. The results indicate that a high quality separation of over 35 peaks in 25 minutes were obtained using a 15 cm Phenomenex LUNA C8 bonded reverse phase column, a three-way water-acetonitrile-methanol nonlinear gradient, and LTV detection at 280 nm.

  11. Fabrication of Glass Fiber Reinforced Composites Based on Bio-Oil Phenol Formaldehyde Resin

    Directory of Open Access Journals (Sweden)

    Yong Cui

    2016-11-01

    Full Text Available In this study, bio-oil from fast pyrolysis of renewable biomass was added by the mass of phenol to synthesize bio-oil phenol formaldehyde (BPF resins, which were used to fabricate glass fiber (GF reinforced BPF resin (GF/BPF composites. The properties of the BPF resin and the GF/BPF composites prepared were tested. The functional groups and thermal property of BPF resin were thoroughly investigated by Fourier transform infrared (FTIR spectra and dynamic thermomechanical analysis (DMA. Results indicated that the addition of 20% bio-oil exhibited favorable adaptability for enhancing the stiffness and heat resistance of phenol formaldehyde (PF resin. Besides, high-performance GF/BPF composites could be successfully prepared with the BPF resin based on hand lay-up process. The interface characteristics of GF/BPF composites were determined by the analysis of dynamic wettability (DW and scanning electron microscopy (SEM. It exhibited that GF could be well wetted and embedded in the BPF resin with the bio-oil addition of 20%.

  12. CHARACTERIZATION OF ALKALINE LIGNINS FOR USE IN PHENOL-FORMALDEHYDE AND EPOXY RESINS

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    Nour Eddine El Mansouri

    2011-05-01

    Full Text Available Besides polyurethanes and polyesters, phenolic and epoxy resins are the most prominent applications for technical lignins in thermosetting materials. To evaluate the potential application of lignin raw materials in phenol formaldehyde and epoxy resins, three types of alkaline lignins were characterized in terms of their structures and thermal properties. The lignin samples analyzed were kraft lignin (LIG-1, soda–rice straw lignin (LIG-2, and soda-wheat straw lignin (LIG-3. FTIR and 1H-NMR methods were used to determine their structure. Gel permeation chromatography (GPC was used to determine the molecular weight distribution (MWD. Differential scanning calorimetry (DSC was used to measure the glass transition temperature (Tg, and thermogravimetric analysis (TGA to determine the thermal stability of lignin samples. Results showed that kraft lignin (LIG-1 has moderate hydroxyl-group content, is rich in G-type units, and has good thermal stability. These properties make it more suitable for direct use in phenol formaldehyde resins, and it is therefore a good raw material for this purpose. The alkaline soda-rice straw lignin (LIG-2 with a high hydroxyl-group content and excellent thermal stability is most suited to preparing lignin-based epoxy resins.

  13. Study on the microstructure evolution of phenol-formaldehyde resin modified by ceramic additive

    Institute of Scientific and Technical Information of China (English)

    JIANG Haiyun; WANG Jigang; DUAN Zhichao; LI Fan

    2007-01-01

    Boron carbide (B4C) was selected as the additive for the modification of a phenol-formaldehyde (PF) resin, and the micro-structural evolution of the modified resin at high temperature was investigated.Results showed that the distribution of B4C particles became uniform at elevated temperatures.The primary oxidation of B4C started to occur at 450℃,and lots of B2O3 was formed above 650℃.By the modification reactions of B,C,the volatiles including CO was converted into amorphous carbon and remained in the resin matrix,which was responsible for maintaining the stability of the resin at high temperatures.

  14. Complexation Between Borate ion and Hydroxyl Groups of Phenol-Formaldehyde Resol Resin

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The complexation reaction between borate ions and phenol-formaldehyde resol resin in aqueous solution was studied by pH measurement, small model molecules and infrared spectroscopy.The results show that the complexation can proceed completely and rapidly at room temperature.Borate ion attacks phenol hydroxyl groups and adjacent position hydroxymethyl groups on the phenol ring of the resin, and forms the coordinate bond between boron atom in borate ion and oxygen atom in the hydroxyl groups. The complexation is a quantitative reaction. The complex is a six member ring containing two oxygens and one boron. The complexation can release hydrogen ions resulting in the decreasing pH in the resin solution.

  15. Synthesis of fluorescent and low cytotoxicity phenol formaldehyde resin (PFR)@Ag composites for cell imaging and antibacterial activity.

    Science.gov (United States)

    Yang, Ping; Dong, Hao; Xia, Jun; Xu, Andong; Shi, Jianjun; He, Jie; Ding, Jianzhong; Li, Dewei

    2015-12-01

    Ag nanoparticles (NPs) were loaded onto the surface of phenol formaldehyde resin (PFR) NPs without any reducing agent. The as-synthesized PFR@Ag composites have low cytotoxicity, which makes them promising antibacterial agents. Furthermore, the good fluorescence of PFR could be used for cell imaging.

  16. Phenol-formaldehyde resins: A quantitative NMR study of molecular structure and molecular dynamics

    Science.gov (United States)

    Ottenbourgs, Benjamin Tony

    Phenol-formaldehyde (PF) resins have been the subject of this work. 13C liquid-state and solid-state NMR has been used to investigate the molecular structure of mainly novolak and partially of resole resins. 1H wideline in combination with 13C solid-state NMR relaxometry has been applied to study the curing and the molecular dynamics of phenolic resins. It was the intention to provide an insight in the relationship between resin composition, resin structure and subsequent resin properties (by means of the molecular dynamics). An improved 13C liquid-state NMR quantification technique of novolaks in THF-CDCl3 solutions is demonstrated. Full quantitative 13C liquid-state spectra of phenol-formaldehyde resins with high signal- to-noise ratio were obtained by using chromium acetylacetonate under optimized spectral conditions within a few hours spectrometer time. Attached proton test (APT) spectra enabled proper peak assignments in the region with significant overlap. For several novolaks, prepared under different catalytic conditions, the degree of polymerization, degree of branching, number average molecular weight, isomeric distribution, and the number of unreacted ortho and para phenol ring positions was determined with a reduced margin of error, by analyzing and integrating the 13C spectra. The power of 13C solid-state NMR in the analysis of cured PF resins is shown. Particular importance was ascribed to the question of the quantifiability of the experiments when it was desired to measure the degree of conversion by means of a 13C CP/MAS contact time study. The network structure present, and thus also the mechanical properties, is critically dependent upon the final degree of conversion obtained after curing. The degree of conversion, which depended on the cure conditions (cure temperature, cure pressure and cure time), was limited by vitrification as was demonstrated by DSC experiments. Changes in the spin-lattice relaxation time T 1H were observed, providing

  17. Synthesis of nanosized tungsten carbide from phenol formaldehyde resin coated precursors

    Institute of Scientific and Technical Information of China (English)

    LUO Ji; GUO Zhimeng; GAO Yuxi; LIN Tao

    2008-01-01

    Nanosized tungsten carbide was synthesized from phenol formaldehyde resin (PF) coated tungsten precursors.The process has three steps in which nanosized tungsten particles were first coated with PF,then the precursors were carburized at 950℃,and finally the carburized powders were treated in flowing wet hydrogen atmosphere at 940℃ to remove the uncombined carbon.The obtained powders were characterizedusing X-ray diffraction analysis (XRD),field-emission scanning electron microscopy (FESEM),small angle X-ray scattering (SAXS),andcombustion-gas-volume method.The results indicated that single-phase WC could be synthesized using excessive PF as carburizer at a muchlower temperature compared with using mixed carbon black.After wet hydrogen treating,the mean size of the obtained WC particles was 94.5nm and the total carbon content was 6.18 wt.%.

  18. A Microfluidic Chip Using Phenol Formaldehyde Resin for Uniform-Sized Polycaprolactone and Chitosan Microparticle Generation

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    Wan-Chen Hsieh

    2013-06-01

    Full Text Available This study develops a new solvent-compatible microfluidic chip based on phenol formaldehyde resin (PFR. In addition to its solvent-resistant characteristics, this microfluidic platform also features easy fabrication, organization, decomposition for cleaning, and reusability compared with conventional chips. Both solvent-dependent (e.g., polycaprolactone and nonsolvent-dependent (e.g., chitosan microparticles were successfully prepared. The size of emulsion droplets could be easily adjusted by tuning the flow rates of the dispersed/continuous phases. After evaporation, polycaprolactone microparticles ranging from 29.3 to 62.7 μm and chitosan microparticles ranging from 215.5 to 566.3 μm were obtained with a 10% relative standard deviation in size. The proposed PFR microfluidic platform has the advantages of active control of the particle size with a narrow size distribution as well as a simple and low cost process with a high throughput.

  19. Fluorescent glutathione probe based on MnO2-phenol formaldehyde resin nanocomposite.

    Science.gov (United States)

    Wang, Xudong; Wang, Dan; Guo, Yali; Yang, Chengduan; Liu, Xiaoyu; Iqbal, Anam; Liu, Weisheng; Qin, Wenwu; Yan, Dan; Guo, Huichen

    2016-03-15

    MnO2-phenol formaldehyde resin (MnO2-PFR) nanocomposite is successfully prepared by a simple chemical reduction process. The resultant MnO2-PFR nanocomposite is well characterized. The absorption band of non-fluorescent MnO2 nanosheets overlaps well with the fluorescence emission of PFR nanoparticles. The green fluorescence of PFR in this nanocomposite can be effectively quenched by fluorescence resonance energy transfer from PFR to MnO2. In the presence of glutathione (GSH), the fluorescence of PFR could be recovered due to MnO2 was reduced to Mn(2+) by GSH. The nanocomposite can be use for detecting glutathione in blood serum.

  20. Ordered SiO2 (phenolic-formaldehyde resin) in situ nanocomposites

    Science.gov (United States)

    Hernández-Padrón, G.; Rojas, F.; Castaño, V. M.

    2004-01-01

    Nanocomposite materials consisting of monodisperse SiO2 particles embedded in a polymerized resin matrix were produced by the adhesion of silica globules on the surface of a chemically modified phenolic-formaldehyde resin (MPFR) substrate that incorporates carboxylic groups in its molecules. Two routes were followed to obtain SiO2 nanoparticles-MPFR materials. The first procedure consisted of the growth of an SiO2 phase concurrently with the presence of MPFR molecules. The second procedure involved the preparation of a monodisperse SiO2 sol that was subsequently mixed with an MPFR solution. The thermal curing of the MPFR resin phase at 80 °C brought about thin SiO2-MPFR flakes from samples obtained from procedure 1 whilst monolithic pieces arose from samples from procedure 2. During the curing process, silanol surface groups of the silica globules reacted with carboxylic groups of the MPFR molecules to create a reinforced SiO2-MPFR substance that displayed ester bonds across the interface. Thermal treatments of specimens prepared by procedure 2 were performed at 150, 250, 400, 600 and 800 °C to monitor the integrity of the resultant hybrid substrates. To assess the characteristics of SiO2-MPFR materials, some of the main chemical, structural and textural characteristics of several specimens have been determined via FTIR, SEM and N2 adsorption studies.

  1. PEMBUATAN AYAKAN MOLEKULER BERBASIS KARBON UNTUK PEMISAHAN N2/O2 DARI PIROLISIS RESIN PHENOL FORMALDEHYDE

    Directory of Open Access Journals (Sweden)

    Imam Prasetyo

    2012-02-01

    Full Text Available Proses pemisahan campuran gas dengan menggunakan carbon molecular sieve (CMS atau ayakan molekuler berbasis karbon merupakan teknologi proses pemisahan yang mulai banyak diterapkan di dalam industri kimia. Dalam penelitian ini, CMS untuk pemisahan N2 dari udara dibuat dari pirolisis bahan polimer sintetis yaitu resin phenol formaldehyde (PF. Prekursor yang berupa resin tersebut dipanaskan dalam retort pada suhu 400-950oC selama 0,5-3 jam yang disertai dengan pengaliran gas N2 ke dalam retort dengan laju 100 mL/jam. Dengan proses pirolisis, atom-atom non-karbon penyusun bahan polimer akan terurai dan menguap sehingga hanya menyisakan arang karbon dengan struktur kerangka atom karbon yang sesuai dengan struktur kerangka dasar rantai polimer. Kemudian karbon hasil prolisis tersebut dipanaskan lebih lanjut pada suhu 750-950oC sambil dialiri gas CO2 selama 1 jam. Pada kondisi ini karbon akan mengalami proses gasifikasi parsial sehingga terbentuk karbon dengan porositas tinggi. Melalui rekayasa proses polimerisasi dan karbonisasi dihasilkan material karbon berpori yang mayoritas porinya adalah mikropori dengan ukuran pori efektif < 2 nm yang dapat dikategorikan sebagai CMS yang dapat dipergunakan untuk memisahkan campuran gas N2-O2.  Pada penelitian ini dihasilkan CMS dengan selektifitas kinetis DN2/DO2 sekitar 3.

  2. Phenol-Formaldehyde Resin-Based Carbons for CO2 Separation at Sub-Atmospheric Pressures

    Directory of Open Access Journals (Sweden)

    Noelia Álvarez-Gutiérrez

    2016-03-01

    Full Text Available The challenge of developing effective separation and purification technologies that leave much smaller energy footprints is greater for carbon dioxide (CO2 than for other gases. In addition to its involvement in climate change, CO2 is present as an impurity in biogas and bio-hydrogen (biological production by dark fermentation, in post-combustion processes (flue gas, CO2-N2 and many other gas streams. Selected phenol-formaldehyde resin-based activated carbons prepared in our laboratory have been evaluated under static conditions (adsorption isotherms as potential adsorbents for CO2 separation at sub-atmospheric pressures, i.e., in post-combustion processes or from biogas and bio-hydrogen streams. CO2, H2, N2, and CH4 adsorption isotherms at 25 °C and up to 100 kPa were obtained using a volumetric equipment and were correlated by applying the Sips model. Adsorption equilibrium was then predicted for multicomponent gas mixtures by extending the multicomponent Sips model and the Ideal Adsorbed Solution Theory (IAST in conjunction with the Sips model. The CO2 uptakes of the resin-derived carbons from CO2-CH4, CO2-H2, and CO2-N2 at atmospheric pressure were greater than those of the reference commercial carbon (Calgon BPL. The performance of the resin-derived carbons in terms of equilibrium of adsorption seems therefore relevant to CO2 separation in post-combustion (flue gas, CO2-N2 and in hydrogen fermentation (CO2-H2, CO2-CH4.

  3. Arsenate sorption by hydrous ferric oxide incorporated onto granular activated carbon with phenol formaldehyde resins coating.

    Science.gov (United States)

    Zhuang, J M; Hobenshield, E; Walsh, T

    2008-04-01

    A simple and effective method was developed using phenol formaldehyde (PF) resins to immobilize hydrous ferric oxide (HFO) onto granular activated carbon (GAC). The resulting sorbent possesses advantages for both the ferric oxide and the GAC, such as a great As-affinity of ferric oxide, large surface area of GAC, and enhanced physical strength. The studies showed that within one hour this sorbent was able to remove 85% of As(V) from water containing an initial As(V) concentration of 1.74 mg l(-1). The As(V) adsorption onto the sorbent was found to follow a pseudo-second order kinetics model. The adsorption isotherms were interpreted in terms of the Langmuir and Freundlich models. The equilibrium data fitted very well to both models. Column tests showed that this sorbent was able to achieve residual concentrations of As(V) in a range of 0.1-2.0 microg l(-1) while continuously treating about 180 bed volume (BV, 130 ml-BV) of arsenate water with an initial As(V) concentration of 1886 microg l(-1) at a filtration rate of 13.5 ml min(-1), i.e., an empty bed contact time (EBCT) of 9.6 min and a gram sorbent contact time (GSCT) of 0.15 min. After passing 635 BV of arsenate water, the exhausted sorbent was then tested by the Toxicity Characteristic Leaching Procedure (TCLP, US EPA Method 1311) test, and classified as non-hazardous for disposal. Hence, this HFO-PF-coated GAC has the capability to remove As(V) from industrial wastewater containing As(V) levels of about 2 mg l(-1).

  4. Antifriction and Construction Materials Based on Modified Phenol-Formaldehyde Resins Reinforced with Mineral and Synthetic Fibrous Fillers

    Science.gov (United States)

    Burmistr, M. V.; Boiko, V. S.; Lipko, E. O.; Gerasimenko, K. O.; Gomza, Yu. P.; Vesnin, R. L.; Chernyayev, A. V.; Ananchenko, B. A.; Kovalenko, V. L.

    2014-05-01

    Novel polymer composite materials (PCM) based on resole phenol-formaldehyde resins modified with polyamide and reinforced with a combination of organic and inorganic fibrous fillers have been developed. PCM are characterized by a Charpy impact strength of up to 250 kJ/m2, an ultimate strength in static bending of up to 468 MPa, an ultimate strength in compression of up to 178 MPa, a Martens thermal stability of up to 300 °C, a friction coefficient of up to 0.12, and mass wear of up to 0.76 mg/(cm2 · km). They can be used for the fabrication of products intended for antifriction and constructional purposes.

  5. One-pot synthesis of biocompatible Te-phenol formaldehyde resin core-shell nanowires with uniform size and unique fluorescent properties by a synergized soft-hard template process

    Energy Technology Data Exchange (ETDEWEB)

    Qian Haisheng; Zhu Enbo; Zheng Shunji; Yang Xingyun; Li Liangchao; Tong Guoxiu [Department of Chemistry, College of Chemistry and Life Science, Zhejiang Normal University, Jinhua 321004 (China); Li Zhengquan; Hu Yong; Guo Changfa [Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004 (China); Guo Huichen, E-mail: shqian@zjnu.cn, E-mail: ghch-2004@hotmail.com [State Key Laboratory of Veterinary Etiological Biology and Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 11, Lanzhou, Gansu 730046 (China)

    2010-12-10

    One-pot hydrothermal process has been developed to synthesize uniform Te-phenol formaldehyde resin core-shell nanowires with unique fluorescent properties. A synergistic soft-hard template mechanism has been proposed to explain the formation of the core-shell nanowires. The Te-phenol formaldehyde resin core-shell nanowires display unique fluorescent properties, which give strong luminescent emission in the blue-violet and green regions with excitation wavelengths of 270 nm and 402 nm, respectively.

  6. Microwave Cure of Phenol-Formaldehyde Adhesive

    OpenAIRE

    高谷, 政広; 田平, 英敏; 岡本, 忠

    2006-01-01

    [Synopsis] Phenol-formaldehyde resin has been used as a versatile material for adhesives and coatings of a wide range of adherends because of its excellent performance in water- resistance, strength against abrasion, and so on. However, it has a drawback of slow rate of cure and relevant emission of formaldehyde gas after bonding. We studied the curing performance under irradiation of microwave for the purpose of looking for a way of accelerating the cure rate of phenol formaldehyde resin. Th...

  7. STUDY ON THE THERMAL ANALYSIS OF THE P-Mo PHENOLIC-FORMALDEHYDE RESIN%磷钼酚醛树脂的热分析研究

    Institute of Scientific and Technical Information of China (English)

    赵会明; 郑怀礼

    2001-01-01

    The influence of amount of the curing agent on P-Mo Phenolic-formaldehyde resin is studied by thermal-weight analysis.The immobilizafion agent of P-Mo Phenolic-formaldehyde resin is hexamethylenetetramine. The apparent kinetic for action of immobilization agent is also studied. The ratio of P-Mo phenolic-formaldehyde resin to immobilization agent is 100: 10, the lost ratio of weight is 30.3% at700℃.The temperature of thermal decomposability is 791.7℃. The apparent active energy is 21.11 kJ/mol.%以六次甲基四胺为磷钼酚醛树脂的固化剂,采用热重分析法研究了固化剂用量对磷钼酚醛树脂性能的影响和磷钼酚醛树脂的固化反应表观动力学。结果表明,磷钼酚醛树脂与固化剂配比为100:10时,700℃下失重率为30.3%,热分解温度为791.7℃,磷钼酚醛树脂固化反应的表观活化能为21.11KJ/mol。

  8. Synthesis of multifunctional Ag@Au@phenol formaldehyde resin particles loaded with folic acids for photothermal therapy.

    Science.gov (United States)

    Yang, Ping; Xu, Qi-Zhi; Jin, Sheng-Yu; Lu, Yang; Zhao, Yang; Yu, Shu-Hong

    2012-07-23

    Multifunctional Ag@Au@ phenol formaldehyde resin (PFR) particles loaded with folic acids (FA) have been designed for killing tumor cells through photothermy conversion under the irradiation of near-infrared (NIR) light. Possessing the virtue of good fluorescence, low toxicity, and good targeting, the nanocomposite consists of an Ag core, an Au layer, a PFR shell, and folic acids on the PFR shell. The Ag@PFR core-shell structure can be prepared with a simple hydrothermal method after preheating. We then filled the PFR shell with a layer of Au by heating and modified the shell with polyelectrolyte to change its surface charge state. To capture tumor cells actively, FA molecules were attached onto the surface of the Ag@Au@PFR particles in the presence of 1-ethyl-3-(3-dimethly aminopropyl) carbodiimide (EDAC) and N-hydroxysuccinimide (NHS). Owing to the excellent property of Au NPs and Ag NPs as photothermal conversion agents, the Ag@Au@ PFR@FA particles can be utilized to kill tumor cells when exposed to NIR light.

  9. Adhesion properties of styrene-butadiene rubber (SBR/Standard Malaysian Rubber (SMR L-based adhesives in the presence of phenol formaldehyde resin

    Directory of Open Access Journals (Sweden)

    2007-10-01

    Full Text Available The adhesion properties, i. e. viscosity, tack and peel strength of styrene-butadiene rubber (SBR/Standard Malaysian Rubber (SMR L-based pressure-sensitive adhesive was studied using phenol formaldehyde resin as the tackifying resin. Toluene was used as the solvent throughout the experiment. SBR composition in SBR/SMR L blend used was 0, 20, 40, 60, 80, 100%. Three different resin loadings, i. e. 40, 80 and 120 parts per hundred parts of rubber (phr were used in the adhesive formulation. The viscosity of adhesive was determined by a HAAKE Rotary Viscometer whereas loop tack and peel strength of paper/polyethylene terephthalate (PET film were measured using a Lloyd Adhesion Tester operating at 30 cm/min. Results indicate that the viscosity of adhesive decreases with increasing % SBR whereas loop tack passes through a maximum value at 20% SBR for all resin loadings. Except for the control sample (without resin, the peel strength shows a maximum value at 60% SBR for the three modes of peel tests. For a fixed % SBR, adhesive sample containing 40 phr phenol formaldehyde resin always exhibits the highest loop tack and peel strength, an observation which is associated to the optimum wettability of adhesive on the substrate.

  10. Liquefaction of cornstalk in hot-compressed phenol-water medium to phenolic feedstock for the synthesis of phenol-formaldehyde resin.

    Science.gov (United States)

    Wang, Mingcun; Xu, Chunbao Charles; Leitch, Mathew

    2009-04-01

    Cornstalk powders were effectively liquefied in a hot-compressed phenol-water medium (1:4 wt/wt). The optimum liquefaction temperature was around 350 degrees C, where the liquid yield attained a maximum at about 70 wt%. The addition of sodium carbonate showed negligible effect over the Liquefaction product yields. When liquefied in phenol-water medium, essentially no phenol was combined with the liquid products, and the cornstalk-derived bio-oils were partially degraded monomeric and oligomeric products with a broad molecular distribution. Resol type bio-based phenol formaldehyde resins were readily synthesized from the cornstalk-derived bio-oils catalyzed by sodium hydroxide.

  11. PF和PUF树脂分子结构对比研究%Comparison of the Molecular Structure between Phenol-formaldehyde and Phenol-urea-formaldehyde Resins

    Institute of Scientific and Technical Information of China (English)

    杜官本; 雷洪; PIZZI Antonio

    2013-01-01

    To confirm the existence of co-condensation in phenol-urea-formaldehyde (PUF) resin and understand the development of molecular structure during the polymerization, the characteristic structure of PUF was analyzed based on the study of structure of phenol-formaldehyde (PF) resin with the help of two main instruments 13C NMR and MALDI-TOF-MS. Analysis results confirmed that the co-condensation among phenol, urea and formaldehyde indeed occurred and formed at the beginning of polymerization. The results also confirmed that structure of copolymer mainly derived from PF resin.%为了判断苯酚-尿素-甲醛(PUF)树脂中原料共缩聚反应是否发生,并确认共缩聚分子形成特点,借助13C核磁共振(13C NMR)和基质辅助激光解析电离飞行时间质谱(MALDI-TOF-MS)两种主要分析仪器,对比研究了苯酚-甲醛(PF)树脂和PUF树脂的结构特点,结果证实了PUF树脂中苯酚、尿素和甲醛3种原料之间共缩聚反应的存在,认为PUF树脂结构以PF树脂为主体,且共缩聚结构主要形成于合成反应初期.

  12. 酚醛树脂基复合材料增韧改性研究进展%Research progress of toughening modification for phenol formaldehyde resin composite

    Institute of Scientific and Technical Information of China (English)

    韩建祥; 胡孝勇

    2013-01-01

    对PF(酚醛树脂)复合材料的性能进行了综述,并概述了PF的合成机制.围绕PF存在的缺点,结合国内外对PF的改性研究,总结出PF的力学性能复合改性、耐热氧复合改性等方法;通过这些改性方法的实施,可使PF复合材料的综合性能进一步提升,最终可得到能满足桥梁100年使用要求的PF复合材料.%The properties of PF (phenol formaldehyde resin) composite were summarized, and the synthesis mechanisms of PF were also summarized. The PF' s composite modification methods in mechanical properties and heat-oxygen resistance were summarized based on PF's disadvantages and PF's modified research at home and abroad. Through implementing these modified methods,the combination property of PF composite was further improved. Finally,the PF composites,which could meet application requirements of bridge life at 100 years,could be obtained.

  13. Synthesis of Fe3O4@phenol formaldehyde resin core-shell nanospheres loaded with Au nanoparticles as magnetic FRET nanoprobes for detection of thiols in living cells.

    Science.gov (United States)

    Yang, Ping; Xu, Qi-Zhi; Jin, Sheng-Yu; Zhao, Yang; Lu, Yang; Xu, Xue-Wei; Yu, Shu-Hong

    2012-01-23

    A magnetic, sensitive, and selective fluorescence resonance energy transfer (FRET) probe for detection of thiols in living cells was designed and prepared. The FRET probe consists of an Fe(3)O(4) core, a green-luminescent phenol formaldehyde resin (PFR) shell, and Au nanoparticles (NPs) as FRET quenching agent on the surface of the PFR shell. The Fe(3)O(4) NPs were used as the core and coated with green-luminescent PFR nanoshells by a simple hydrothermal approach. Au NPs were then loaded onto the surface of the PFR shell by electric charge absorption between Fe(3)O(4)@PFR and Au NPs after modifying the Fe(3)O(4)@PFR nanocomposites with polymers to alter the charge of the PFR shell. Thus, a FRET probe can be designed on the basis of the quenching effect of Au NPs on the fluorescence of Fe(3)O(4)@PFR nanocomposites. This magnetic and sensitive FRET probe was used to detect three kinds of primary biological thiols (glutathione, homocysteine, and cysteine) in cells. Such a multifunctional fluorescent probe shows advantages of strong magnetism for sample separation, sensitive response for sample detection, and low toxicity without injury to cellular components.

  14. [The early detection of allergic dermatoses and mycoses of the feet in workers in contact with phenol-formaldehyde resins].

    Science.gov (United States)

    Bannikov, E A; Anton'ev, A A; Makarova, L E; Beker, V P; Kiseleva, L L

    1990-01-01

    Hypersensitivity to phenolformaldehyde resins was detected in 16.2% of workers exposed to them, allergic dermatitis and eczemas in 21.5%, mycoses of the soles in 13.5%, premorbid shifts in half of the examinees. Mycoses of the soles prevailed in subjects with a history of dermatitis and in patients suffering from allergic dermatoses.

  15. Selective Removal of Toxic Metals like Copper and Arsenic from Drinking Water Using Phenol-Formaldehyde Type Chelating Resins

    Directory of Open Access Journals (Sweden)

    Debasis Mohanty

    2009-01-01

    Full Text Available The concentration of different toxic metals has increased beyond environmentally and ecologically permissible levels due to the increase in industrial activity. More than 100 million people of Bangladesh and West Bengal in India are affected by drinking ground water contaminated with arsenic and some parts of India is also affected by poisoning effect of copper, cadmium and fluoride. Different methods have been evolved to reduce the arsenic concentration in drinking water to a maximum permissible level of 10 μg/L where as various methods are also available to separate copper from drinking water. Of the proven methods available today, removal of arsenic by polymeric ion exchangers has been most effective. While chelating ion exchange resins having specific chelating groups attached to a polymer have found extensive use in sorption and pre concentration of Cu2+ ions. Both the methods are coupled here to separate and preconcentrate toxic metal cation Cu2+ and metal anion arsenate(AsO4– at the same time. We have prepared a series of low-cost polymeric resins, which are very efficient in removing copper ion from drinking water and after coordinating with copper ion they act as polymeric ligand exchanger, which are efficiently removing arsenate from drinking water. For this purpose Schiff bases were prepared by condensing o-phenylenediamine with o-, m-, and p-hydroxybenzaldehydes. Condensing these phenolic Schiff bases with formaldehyde afforded the chelating resins in high yields. These resins are loaded with Cu2+, Ni2+ 2+, and Fe3+ ions. The resins and the polychelates are highly insoluble in water. In powdered form the metal ion-loaded resins are found to very efficiently remove arsenate ion from water at neutral pH. Resins loaded with optimum amount of Cu2+ ion is more effective in removing arsenate ions compared to those with Fe3+ ion, apparently because Cu2+ is a stronger Lewis acid than Fe3+. Various parameters influencing the removal of the

  16. Model-free Kinetic Study of Phenol Formaldehyde Resin Cure%酚醛树脂固化的非模型拟合动力学研究

    Institute of Scientific and Technical Information of China (English)

    叶晓川; 曾黎明; 张超; 陈雷

    2012-01-01

    The curing behavior of novolac type phenolic resin was studied through differential scanning calorimetry (DSC) using model-free (isoconversion) kinetic methods. In the model-free kinetic study, Friedman, Flynn-Wall-Ozawa, and Kissinger-Akahira-Sunose methods were used to calculate the curing activation energy. The dependence curve of activation energy on conversion and the piecewise model fitting results both displayed a change in the kinetic reaction mechanism from the autocatalytic to n-order regime. According to the isothermal prediction results, the model-free kinetic methods show excellent prediction ability. Also, Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose methods were found to show similar results in analyzing the curing behavior of this novolac resin.%根据不等温差示扫描量热曲线,采用非模型拟合动力学法对酚醛树脂的固化动力学进行了研究.基于Friedman,Flynn-Wall-Ozawa和Kissinger-Akahira-Sunose 3种模型计算得到了固化速率及活化能与固化度的关系,进而对此树脂体系的固化反应阶段及固化行为进行了分析,并对等温固化行为进行预测.结果表明,固化反应逐渐从自催化反应机理转变为n阶反应机理,与模型拟合法研究的结果基本吻合.对Friedman,Flynn-Wall-Ozawa,Kissinger-Akahira-Sunose 3种动力学方法进行比较发现,3种方法都显示了较好的拟合结果.其中,Flynn-Wall-Ozawa和Kissinger-Akahira-Sunose两种方法的结果十分接近,并能对固化行为进行准确地反映.

  17. 热塑性酚醛树脂合成中废水游离酚含量的测定方法%The Method for Determination of Free Phenol Content in Waste Water During Thermal Plastic Phenol-Formaldehyde Resin Synthesis Process

    Institute of Scientific and Technical Information of China (English)

    张苏静; 黄仁和

    2013-01-01

    工业生产中,热塑性酚醛树脂的合成过程会产生大量废水,废水中含有部分游离态的苯酚、甲醛,为了合理回收利用废水,需要对游离酚含量进行测定.本文比较并分析了目前现有的两种不同的测定游离酚的方法,得出用溴量法更适合于测定废水中的游离酚,该方法准确度及精确度较高,适合测定热塑性酚醛树脂废水中的游离酚含量.将合成过程产生的废水分步脱出,用溴量法测定其酚含量,然后将分步脱出的废水采取不同方法再回收使用.%In industrial production, the synthesizing process of thermoplastic phenol-formaldehyde resin will produce large quantities of waste water, which contains part of free phenol and formaldehyde. In order to recycle the waste water reasonably, it is necessary to determine the content of free phenol. This paper compares and analyzes the two methods of determining free phenol content nowadays. The analysis results show that bromometry is better for the determination. It has high accuracy, and bromometry is suitable for determining the free phenol content in the thermal plastic phenol-formaldehyde resin waste water. Free phenol content that occur during the fractional dewatering step is determined by bromometry, and the waste water of different dewatering step is recycled by different methods.

  18. Preparation and characterization of phenol-formaldehyde adhesives modified with enzymatic hydrolysis lignin.

    Science.gov (United States)

    Jin, Yanqiao; Cheng, Xiansu; Zheng, Zuanbin

    2010-03-01

    Phenol-formaldehyde (PF) adhesives modified with enzymatic hydrolysis lignin (EHL) were synthesized by a one-step process. The phenol component of the PF adhesives was partially substituted by EHL extracted from the residues of cornstalks used to produce bio-ethanol. The EHL-PF adhesives were used to prepare plywoods by hot-pressing. The pH value, viscosity, solid content, free phenol content, free formaldehyde content and brominable substance content of EHL-PF resins were investigated. The bonding strengths of the plywoods were determined, and the influences of the replacement percentage of phenol by EHL (a) and the NaOH content (b) on the properties of the adhesives were investigated. The results showed that the performance of the modified adhesives and the plywoods glued with them almost met the Chinese National Standard (GB/T 14732-2006) for first grade plywood when 20 wt% of the phenol was replaced by EHL.

  19. Preparation, Characterization, and Properties of In Situ Formed Graphene Oxide/Phenol Formaldehyde Nanocomposites

    Directory of Open Access Journals (Sweden)

    Weihua Xu

    2013-01-01

    Full Text Available Graphene oxide (GO has shown great potential to be used as fillers to develop polymer nanocomposites for important applications due to their special 2D geometrical structure as well as their outstanding mechanical, thermal, and electrical properties. In this work, GO was incorporated into phenol formaldehyde (PF resin by in situ polymerization. The morphologies and structures of GO sheets were characterized by FTIR, XRD, and AFM methods. The structure and properties of the GO/PF nanocomposites were characterized using FTIR, XRD, DSC, and TGA methods. Effects of GO content, reactive conditions, and blending methods on the structure and properties of GO/PF nanocomposites were studied. It was found that due to the well dispersion of GO sheets in polymer matrix and the strong interfacial interaction between the GO sheets and PF matrix, the thermal stability and thermal mechanical properties of the GO/PF nanocomposites were greatly enhanced.

  20. Influences of hydrophobic associating polymer on dispersion characteristics of low-solubility phenol-formaldehyde resin in NaCl solution%疏水缔合聚合物对NaCl溶液中低溶解度PF分散特性的影响

    Institute of Scientific and Technical Information of China (English)

    赵丹; 李明远; 林梅钦; 彭勃; 董朝霞

    2013-01-01

    为改善LPFR(低溶解度酚醛树脂)在低矿化度水中的分散稳定性,以HAP(疏水缔合聚合物)作为LPFR的稳定剂,并测定了分散体系在去离子水或NaC1溶液中的流体力学直径(Dh)、Zeta电位、浊度及稳定时间.结果表明:当LPFR水溶液浓度为300 mg/L时,LPFR以单分子或较小的分子聚集体形式存在于去离子水中,Zeta电位较高、浊度较小且稳定性良好;加入NaC1后,LPFR形成了较大的分子聚集体,Zeta电位降低、浊度增大且稳定性变差;引入HAP后,LPFR/HAP因疏水缔合作用而形成了Dh较小的复合分子聚集体,其Zeta电位较大,浊度明显降低,稳定性增强;HAP能明显改善LPFR在NaC1溶液中的分散特性及稳定性.%In order to improve dispersion stability of LPFR (low-solubility phenol-formaldehyde resin) in low salinity water,with HAP(hydrophobic associating polymer) as stabilizer of LPFR,and the some properties(such as hydrodynamic diameter(Dh),Zeta potential,turbidity,and stable time) of dispersion system were tested in deionized water or in NaCl solution.The results showed that the LPFR with single molecule or smaller molecular aggregation form exists in deionized water,so the system had the higher Zeta potential,smaller turbidity and good stability when LPFR solution concentration was 300 mg/L.The Zeta potential and stability of system were decreased,and the turbidity was increased because the LPFR with larger molecular aggregation form exists in system when the NaC1 was introduced into system.The Zeta potential was higher,the turbidity was obviously decreased,and the stability was increased because the LPFR/HAP with smaller Dh and compound molecular aggregation form exists in system by hydrophobic association when the HAP was introduced into system.The HAP could obviously improve LPFR's dispersion characteristics and stability in NaC1 solution.

  1. Surface modification of a natural graphite/phenol formaldehyde composite plate with expanded graphite

    Energy Technology Data Exchange (ETDEWEB)

    Li, Dongjie; Wang, Yuxin; Xu, Li; Lu, Jun; Wu, Qian [State Key Laboratory of Chemical Engineering, Chemical Engineering Research Center, School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Tianjin 300072 (China)

    2008-09-01

    Natural graphite/phenol formaldehyde (NG/PF) resin composite plates modified with thin layers of expanded graphite (EG) are fabricated by mold compression to lower the contact resistance between the plates and gas diffusion layers (GDLs). The modification considerably reduces contact resistance versus bare NG/PF plates. The extent of the decrease in contact resistance is influenced by the expanded volume of EG used. A low contact resistance of 1.42 m{omega} cm{sup 2} persists for the EG (150 ml g{sup -1})-modified NG/PF plates despite the PF content, whereas that of bare plates increases from 3.62 to 17.01 m{omega} cm{sup 2} as PF content changes from 5 wt% to 30 wt%. With increasing EG thickness on the surface of NG/PF plates, contact resistance at first decreases and then approaches a constant value when the NG layer exceeds 40 {mu}m. More importantly, the total electrical resistance, as expressed by volume resistance, can be reduced by applying EG layers to NG/PF composite plates. The reduction of total resistance is more remarkable for the composite plates with high PF content because the bulk resistance of the EG layer can be well compensated by the decrease of contact resistance at a proper range of EG layer thickness. (author)

  2. RAPID WAY TO ASSESS THE SAFETY OF PRODUCTS FROM PHENOL-FORMALDEHYDE PLASTICS

    Directory of Open Access Journals (Sweden)

    T. A. Kuchmenko

    2014-01-01

    Full Text Available Summary. An express method for determining of volatile components in the products of phenol-formaldehyde plastics is developed by detecting them in the equilibrium gas phase using the piezosensors array. The sorption of substances-marker vapor which are the main pollutants in the air diffusing from plastic household products has been studied under identical conditions. The array of 8 piezosensors is selected providing minimal impact of water vapor on the microbalance results; maximum sensitivity to one / several classes of organic compounds; identification of phenol / formaldehyde in the mixtures. A method of evaluation the level of emissions of phenol, formaldehyde, toluene, acetone from household plastic products is developed using the piezosensors array. It has been proposed the ranking samples nonfood polymers into groups according to the danger degree based on the total content of volatile organic compounds and the presence of phenol / formaldehyde. Accuracy of the phenol determination in polymers is verified by standard spectrophotometric method with 4-aminoantipyrine, it is shown the results of both methods satisfactorily converge. The proposed method can significantly reduce the economic and time costs on analysis and expand the analytical information about the content of other volatile substances in a single measurement.

  3. Phenol-formaldehyde intumescent coating composition and coating prepared therefrom

    Science.gov (United States)

    Salyer, Ival O. (Inventor); Fox, Bernard L. (Inventor)

    1986-01-01

    Intumescent coatings which form a thick, uniform, fine celled, low density foam upon exposure to a high intensity heat flux or flame are disclosed, the invention coatings comprise phenolic resin prepolymer containing a blowing agent and a nucleating agent; in the preferred embodiments the coatings also contains a silicone surfactant, the coatings are useful in thermal and fire protection systems.

  4. 水溶性酚醛树脂-水玻璃互穿网络结构耐温堵剂的合成与性能评价%Synthesis and performance evaluation of high temperature plugging agent with IPN gel formed with water soluble phenol-formaldehyde resin and sodium silicate

    Institute of Scientific and Technical Information of China (English)

    罗懿

    2016-01-01

    以水溶性酚醛树脂、水玻璃和抑水剂为材料,基于溶胶‐凝胶技术合成出一种互穿网络结构的有机‐无机凝胶体系。互穿网络凝胶体系的交联时间随水溶性酚醛树脂浓度增大而缩短,交联强度则增强。当体系中水玻璃质量分数为0~3%时,交联时间随浓度增大而延长,交联强度随浓度增大而增强。水溶性酚醛树脂‐水玻璃互穿网络结构致密且匀称,满足深部封堵的要求,可作为耐温堵剂使用。%In this paper ,an interpenetrating network (IPN ) organic‐inorganic gel system was prepared by water soluble phenol‐formaldehyde resin ,sodium silicate and water‐resistant agent based on sol‐gel technology .The gelation time of IPN gel system shortens with the concentration increase of water soluble phenol‐formaldehyde resin ,while gelation strength increase .When the concentration of sodium silicate is 0 ~ 3% , the gelation time lengthens and the gelation strength enhances with concentration increase .The interpenetrating network structure formed by water soluble phenolic‐resin and sodium silicate is dense and symmetrical .The system can be used as a high temperature plugging agent and satisfied the deep sealing condition .

  5. Synthesis and Characterization of Periodic Mesoporous Organosilicas as Anion-Exchance Resins for Perrhenate Adsorption.

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byunghwan [Korea Institute of Industrial Technology, ChonAn, Korea; Im, Hee-Jung [ORNL; Luo, Huimin [ORNL; Hagaman, Edward {Ed} W [ORNL; Dai, Sheng [ORNL

    2005-01-01

    A new methodology to immobilize ionic liquids through the use of a bridged silsesquioxane N-(3-triethoxysilylpropyl), N(3)-3-trimethoxysilylpropyl-4,5-dihydroimidazolium iodide that incorporates an ionic functionality for the assembly of novel periodic mesoporous organosilica (PMO) materials has been developed. The resulting PMO materials were investigated for use as novel anion exchange resins for the separation of perrhenate anions in aqueous solution. As compared with cetyltrimethylammonium chloride, 1-hexadecane-3-methylimidazolium bromide has been demonstrated to be a more efficient surfactant template for the generation of mesopores and surface areas for such PMO materials.

  6. Synthesis and characterization of phenol/formaldehyde nanocomposites: Studying the effect of incorporating reactive rubber nanoparticles or Cloisite-30B nanoclay on the mechanical properties, morphology and thermal stability

    Directory of Open Access Journals (Sweden)

    Walaa S.E. Solyman

    2017-01-01

    Full Text Available In this work, phenol/formaldehyde nanocomposites were synthesized using reactive rubber nanoparticles (RRNP and cloisite30B nanoclay with different percentages and were fully investigated. A little amount of these nanomaterials enhanced the mechanical properties of the produced composites. This enhancement is attributed to the interaction of these nanomaterials with the bakelite matrix. In bakelite/RRNP, the mechanical properties enhancement is due to the chemical connection of RRNP to the bakelite matrix while in bakelite/Cloisite30B, this enhancement is due to polar/polar interaction. It was observed that the composites exhibited an intercalated disordered structure by means of Xray diffraction (XRD and transmission electronic microscopy. The crosslinking density of the bakelite network was greatly influenced by the presence and type of nanomaterial that was added to the resin. The thermal stability was investigated with TGA/DSC which proved that these nanocomposite are (10–20% more thermally stable than neat Bakelite resin.

  7. Synthesis of sulphonated mesoporous phenolic resins and their application in esterification and asymmetric aldol reactions

    Energy Technology Data Exchange (ETDEWEB)

    Muylaert, Ilke [Department of Inorganic and Physical Chemistry, Ghent University, Center for Ordered Materials, Organometallics and Catalysis (COMOC), Krijgslaan 281-S3, 9000 Ghent (Belgium); Verberckmoes, An, E-mail: an.verberckmoes@hogent.be [Department of Inorganic and Physical Chemistry, Ghent University, Center for Ordered Materials, Organometallics and Catalysis (COMOC), Krijgslaan 281-S3, 9000 Ghent (Belgium); Associated Faculty of Applied Engineering Sciences, University College Ghent, Valentin Vaerwyckweg 1, 9000 Ghent (Belgium); Spileers, Jeremy [Associated Faculty of Applied Engineering Sciences, University College Ghent, Valentin Vaerwyckweg 1, 9000 Ghent (Belgium); Demuynck, Anneleen; Peng, Li; De Clippel, Filip; Sels, Bert [Katholieke Universiteit Leuven, Centre for Surface Chemistry and Catalysis (COK), Kasteelpark Arenberg 23, 3001 Heverlee (Belgium); Van Der Voort, Pascal, E-mail: pascal.vandervoort@ugent.be [Department of Inorganic and Physical Chemistry, Ghent University, Center for Ordered Materials, Organometallics and Catalysis (COMOC), Krijgslaan 281-S3, 9000 Ghent (Belgium)

    2013-02-15

    Mesoporous phenolic resins were functionalized with sulphonic acid groups by four different types of sulphonation procedures: (i) direct sulphonation on the aromatic ring, (ii) alkyl sulphonation of the aromatic ring, and functionalizations of the phenolic hydroxyl surface by using an aryl silane, 2-(4-chlorosulphonylphenyl)ethyl trichlorosilane (iii) or a propyl silane, 3-mercaptopropyltrimethoxysilane (iv). The highest acidity loadings were obtained through direct sulphonation with fuming sulphuric acid (1.90 mmol H{sup +} g{sup −1}) or chlorosulphonic acid (1.31 mmol H{sup +} g{sup −1}) and these materials showed the highest conversion (97+ %) in Fischer esterification of acetic acid with propanol. However, the alkyl sulphonic groups, obtained through sulphonation procedure (ii) showed the highest stability in terms of maintenance of their acidity after use in consecutive catalytic runs or leaching treatments. This was demonstrated both through evaluation of the regenerated catalysts in a consecutive esterification run and during a leaching resistance test in aqueous medium. Moreover, the developed sulphonated mesoporous phenolic resins are presented as novel support for the non-covalent immobilization of an L-phenylalanine derived chiral diamine organocatalyst for asymmetric aldol reactions. The immobilization is established by an acid–base interaction between the sulphonic acid group and the amine function. The acidity and in particular the electronic withdrawing environment of the sulphonic acid groups influence enormously the catalytic performance of the non-covalent immobilized chiral diamine catalyst (aromatic > aliphatic). - Highlights: ► Different types of sulphonation procedures for mesoporous phenolic resins. ► Influence of acidity and electronic withdrawing environment. ► Novel support for non-covalent immobilization of chiral diamine catalyst. ► Catalytic performance in esterification and asymmetric aldol condensation. ► Demonstration

  8. Preparation and thermal properties of mesoporous silica/phenolic resin nanocomposites via in situ polymerization

    Directory of Open Access Journals (Sweden)

    J. Lv

    2012-10-01

    Full Text Available In order to enhance the adhesion between inorganic particles and polymer matrix, in this paper, the mesoporous silica SBA-15 material was synthesized by the sol-gel method. The surface of SBA-15 was modified using γ-glycidyloxypropyltrimethoxysilane (GOTMS as a coupling agent, and then mesoporous silica/phenolic resin (SBA-15/PF nanocomposites were prepared via in situ polymerization. The structural parameters and physical properties of SBA-15, SBA-15-GOTMS (SBA-15 surface treated using GOTMS as coupling agents and E-SBA-15/PF (SBA-15/PF nanocomposites extracted using ethanol as solvent were characterized by X-ray diffraction (XRD, N2 adsorption-desorption, Fourier transform infrared spectroscopy (FTIR, scanning electron microscopy (SEM, transmission electron microscopy (TEM and thermogravimetric analysis (TGA. The thermal properties of the nanocomposites were studied by differential scanning calorimetry (DSC and thermogravimetric analysis (TGA. The results demonstrated that the GOTMS were successfully grafted onto the surface of SBA-15, and chemical bonds between PF and SBA-15-GOTMS were formed after in situ polymerization. In addition, it is found that the in situ polymerization method has great effects on the textural parameters of SBA-15. The results also showed that the glass transition temperatures and thermal stability of the PF nanocomposites were obviously enhanced as compared with the pure PF at silica contents between 1–3 wt%, due to the uniform dispersion of the modified SBA-15 in the matrix.

  9. Ultrafast hydrothermal synthesis of high quality magnetic core phenol-formaldehyde shell composite microspheres using the microwave method.

    Science.gov (United States)

    You, Li-Jun; Xu, Shuai; Ma, Wan-Fu; Li, Dian; Zhang, Yu-Ting; Guo, Jia; Hu, Jack J; Wang, Chang-Chun

    2012-07-17

    An ultrafast, facile, and efficient microwave hydrothermal approach was designed to fabricate magnetic Fe(3)O(4)/phenol-formaldehyde (PF) core-shell microspheres for the first time. The structure of the Fe(3)O(4)/PF core-shell microspheres could be well controlled by the in situ polycondensation of phenol and formaldehyde with magnetic Fe(3)O(4) clusters as the seeds in an aqueous solution without any surfactants. The effect of synthetic parameters, such as the feeding amounts of phenol, the dosages of formaldehyde, the reaction temperatures, and the microwave heating time, on the morphologies and sizes of the Fe(3)O(4)/PF microspheres were investigated in details. The phenol-formaldehyde shell is found to be evenly coated on Fe(3)O(4) clusters within 10 min of the irradiation. The as-prepared microspheres were highly uniform in morphology, and the method was found to allow the shell thickness to be finely controlled in the range of 10-200 nm. The properties of the composite microspheres were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetic analysis (TGA), Fourier transform infrared (FT-IR) spectra, X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). The as-prepared Fe(3)O(4)/PF microspheres were monodisperse and highly dispersible in water, ethanol, N,N-dimethyformamide, and acetone, a beneficial quality for the further functionalization and applications of the Fe(3)O(4)/PF microspheres.

  10. Multicenter Patch Testing With a Resol Resin Based on Phenol and Formaldehyde Within the International Contact Dermatitis Research Group

    DEFF Research Database (Denmark)

    Isaksson, M.; Ale, I.; Andersen, Klaus Ejner

    2015-01-01

    Background Contact allergy to phenol-formaldehyde resins (PFRs) based on phenol and formaldehyde is not detected by a p-tertiary-butylphenol-formaldehyde resin included in most baseline patch test series. Objective The aims of this study were to investigate the contact allergy rate to PFR-2...

  11. Mesoporous polymer networks-ultraporous DVB resins by hard-templating of close-packed silica spheres.

    Science.gov (United States)

    Wilke, Antje; Weber, Jens

    2012-05-14

    The preparation of ultraporous polymer resins using a straightforward hard-templating synthesis is presented. Self-assembly of silica nanospheres into densely packed glasses allows an easy preparation of templates. Polydivinylbenzene resins with surface areas of up to 1000 m(2) g(-1) are synthesized as a model system and porosity analysis reveals bimodal porosity (spherical mesopores and micropores within the pore walls). The prepared systems can be further functionalized without loss of porosity as demonstrated by sulfonation. Because of their large pore sizes (13-28 nm), they are efficient adsorbents also for large molecules. Finally, the systems can also be used as model systems for the study of the pore drying and collapse process, which is of crucial importance for any application of mesoporous polymers.

  12. Direct synthesis of graphitic mesoporous carbon from green phenolic resins exposed to subsequent UV and IR laser irradiations

    Science.gov (United States)

    Sopronyi, Mihai; Sima, Felix; Vaulot, Cyril; Delmotte, Luc; Bahouka, Armel; Matei Ghimbeu, Camelia

    2016-12-01

    The design of mesoporous carbon materials with controlled textural and structural features by rapid, cost-effective and eco-friendly means is highly demanded for many fields of applications. We report herein on the fast and tailored synthesis of mesoporous carbon by UV and IR laser assisted irradiations of a solution consisting of green phenolic resins and surfactant agent. By tailoring the UV laser parameters such as energy, pulse repetition rate or exposure time carbon materials with different pore size, architecture and wall thickness were obtained. By increasing irradiation dose, the mesopore size diminishes in the favor of wall thickness while the morphology shifts from worm-like to an ordered hexagonal one. This was related to the intensification of phenolic resin cross-linking which induces the reduction of H-bonding with the template as highlighted by 13C and 1H NMR. In addition, mesoporous carbon with graphitic structure was obtained by IR laser irradiation at room temperature and in very short time periods compared to the classical long thermal treatment at very high temperatures. Therefore, the carbon texture and structure can be tuned only by playing with laser parameters, without extra chemicals, as usually required.

  13. Synthesis and properties of phloroglucinol-phenol-formaldehyde carbon aerogels and xerogels.

    Science.gov (United States)

    Jirglová, Hana; Pérez-Cadenas, Agustín F; Maldonado-Hódar, Francisco J

    2009-02-17

    Carbon aerogels and xerogels were successfully prepared from phloroglucinol-phenol mixtures and characterized by different techniques to determine their potential. We examined the influence of the phloroglucinol/phenol ratio, reactant concentration, cure conditions, and drying method on the morphology and porosity of the samples. The gelation time was found to be independent of the phloroglucinol/phenol ratio in spite of the different reactivities of both monomers. In general, carbon aerogels have a high volume of mesopores and of micropores without diffusion restrictions. Carbon xerogels are denser materials without mesopores but with a well-developed microporosity that shows a strong molecular sieve effect. Therefore, while micro-/mesoporous carbon aerogels can be used as catalyst supports or VOC adsorbents, the microporous carbon xerogel could offer high selectivity in the separation of small molecules from gaseous mixtures.

  14. Tribological Behavior of TiC/a-C : H-Coated and Uncoated Steels Sliding Against Phenol-Formaldehyde Composite Reinforced with PTFE and Glass Fibers

    NARCIS (Netherlands)

    Shen, J.T.; Pei, Y.T.; Hosson, J.Th.M. De

    2013-01-01

    Tribological experiments on phenol-formaldehyde composite reinforced with polytetrafluoroethylene (PTFE) and glass fibers were performed against 100Cr6 steel and TiC/a-C:H thin film-coated 100Cr6 steel. In both cases, the coefficient of friction increases with increasing sliding distance until a ste

  15. Mesoporous carbon adsorbents from melamine-formaldehyde resin using nanocasting technique for CO2 adsorption.

    Science.gov (United States)

    Goel, Chitrakshi; Bhunia, Haripada; Bajpai, Pramod K

    2015-06-01

    Mesoporous carbon adsorbents, having high nitrogen content, were synthesized via nanocasting technique with melamine-formaldehyde resin as precursor and mesoporous silica as template. A series of adsorbents were prepared by varying the carbonization temperature from 400 to 700°C. Adsorbents were characterized thoroughly by nitrogen sorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), elemental (CHN) analysis, Fourier transform infrared (FTIR) spectroscopy and Boehm titration. Carbonization temperature controlled the properties of the synthesized adsorbents ranging from surface area to their nitrogen content, which play major role in their application as adsorbents for CO2 capture. The nanostructure of these materials was confirmed by XRD and TEM. Their nitrogen content decreased with an increase in carbonization temperature while other properties like surface area, pore volume, thermal stability and surface basicity increased with the carbonization temperature. These materials were evaluated for CO2 adsorption by fixed-bed column adsorption experiments. Adsorbent synthesized at 700°C was found to have the highest surface area and surface basicity along with maximum CO2 adsorption capacity among the synthesized adsorbents. Breakthrough time and CO2 equilibrium adsorption capacity were investigated from the breakthrough curves and were found to decrease with increase in adsorption temperature. Adsorption process for carbon adsorbent-CO2 system was found to be reversible with stable adsorption capacity over four consecutive adsorption-desorption cycles. From three isotherm models used to analyze the equilibrium data, Temkin isotherm model presented a nearly perfect fit implying the heterogeneous adsorbent surface.

  16. Studies on Glass Reinforced Epoxy Resin Using Vulkadur- A as Crosslinking Agent both in Presence and Absence of Carbon Black and other Non black Fillers

    Directory of Open Access Journals (Sweden)

    T. K. Ghosh

    1974-04-01

    Full Text Available Epoxy resin can be reinforced with glass (fabric form in presence of Vulkadur-A, a phenol formaldehyde resin containing a hardening agent. Overall enhancement in mechanical properties has been found stocks cured with Vulkadur-A containing 2.5 parts of carbon black as filler.

  17. Thermal rearrangement of novolak resins used in microlithography

    Science.gov (United States)

    Hardy, Ricky; Zampini, Anthony; Monaghan, Michael J.; O'Leary, Michael J.; Cardin, William J.; Eugster, Timothy J.

    1995-06-01

    Changes in phenolic-formaldehyde resin properties are described in terms of thermal exposure. At high temperature, resin molecular weight, dissolution properties and chemical composition change depending on the presence or absence of monomers. Without monomer in the resin melt at 220 degree(s)C, resin molecular weight increases with a corresponding decrease in dissolution rate. In the presence of monomer, molecular weight generally decreases. Dissolution rate may fluctuate depending on the monomer mixture. Three,five- Xylenol and 2,3,5-trimethylphenol co-monomers induced the most extreme changes in resin properties with thermal treatment. Resin degradation-recombination processes suggest a classical Friedel-Craft rearrangement mechanism.

  18. PREPARATION OF SULFOMETHYLATED PHENOL FORMALDEHYDE RESIN%磺甲基酚醛树脂的制备

    Institute of Scientific and Technical Information of China (English)

    王庆; 刘福胜; 于世涛

    2008-01-01

    以亚硫酸氢钠/亚硫酸钠为磺化剂,苯酚和甲醛为原料,经苯酚磺甲基化反应和缩聚反应制备了磺甲基酚醛树脂.分别考察了羟甲基磺酸钠的合成反应、苯酚磺甲基化反应和缩聚反应的主要影响因素,羟甲基磺酸钠较佳合成工艺为n(NaHSO3);n(Na2SO3): n(HCHO)=1:1:2.3,反应温度60℃,反应3 h;苯酚磺甲基化反应的较佳反应条件为n(羟甲基磺酸钠):n(苯酚)=O.7;1,反应温度90℃,反应1 h,pH=9;缩聚反应的较佳反应条件为:n(羟甲基磺酸钠);n(苯酚):n(甲醛)=O.7:1:1.2,pH=9,反应温度100℃,反应时间为3 h.产物较佳干燥温度为100℃,较佳条件下磺甲基酚醛树脂产物的平均收率为102.7%,质量分数为10%水溶液的平均粘度为5.84 mPa·s,不溶物质量分数≤3%.对羟甲基磺酸钠和磺甲基酚醛树脂进行了红外光谱表征.

  19. Hydrogen Bonding-Mediated Microphase Separation during the Formation of Mesoporous Novolac-Type Phenolic Resin Templated by the Triblock Copolymer, PEO-b-PPO-b-PEO

    Directory of Open Access Journals (Sweden)

    Wei-Cheng Chu

    2013-11-01

    Full Text Available After blending the triblock copolymer, poly(ethylene oxide-b-propylene oxide-b-ethylene oxide (PEO-b-PPO-b-PEO with novolac-type phenolic resin, Fourier transform infrared spectroscopy revealed that the ether groups of the PEO block were stronger hydrogen bond acceptors for the OH groups of phenolic resin than were the ether groups of the PPO block. Thermal curing with hexamethylenetetramine as the curing agent resulted in the triblock copolymer being incorporated into the phenolic resin, forming a nanostructure through a mechanism involving reaction-induced microphase separation. Mild pyrolysis conditions led to the removal of the PEO-b-PPO-b-PEO triblock copolymer and formation of mesoporous phenolic resin. This approach provided a variety of composition-dependent nanostructures, including disordered wormlike, body-centered-cubic spherical and disorder micelles. The regular mesoporous novolac-type phenolic resin was formed only at a phenolic content of 40–60 wt %, the result of an intriguing balance of hydrogen bonding interactions among the phenolic resin and the PEO and PPO segments of the triblock copolymer.

  20. Efficient removal of aniline by a water-compatible microporous and mesoporous hyper-cross-linked resin and XAD-4 resin: A comparative study

    Science.gov (United States)

    Xiao, Guqing; Long, Liping

    2012-06-01

    A novel water-compatible microporous and mesoporous hyper-cross-linked resin modified with phenolic hydroxyl group (named as GQ-03) was synthesized to remove aniline in aqueous solution as compared with XAD-4. The maximum adsorption capacity of GQ-03 emerged at the molecular state for both aniline and p-cresol while the pH dependency trend of aniline adsorbed onto XAD-4 was accordant with the dissociation curve of aniline. The ionic strength influenced the adsorption obviously. The pseudo-first-order rate equation could describe the adsorption process of aniline onto GQ-03 in two stages while this equation could characterize the entire adsorption process of XAD-4. The adsorption isotherms could be correlated to the Freundlich model, higher KF and n values for GQ-03 than XAD-4. The breakthrough capacity and the total adsorption capacity of GQ-03 and XAD-4 was up to 47.2 mg mL-1 and 28.3 mg mL-1, 271.7 mg mL-1 and 115.6 mg mL-1, respectively. The size matching between the pore diameter of GQ-03 and the molecular size of aniline, and hydrogen bonding between GQ-03 and aniline resulted in the larger adsorption capacity.

  1. Phenol resin-based supports of inclined workings

    Energy Technology Data Exchange (ETDEWEB)

    Boldin, V.M.; Krivoshchekova, N.P.; Fedorova, G.G.

    1980-10-01

    This article evaluates experimental tubing supports produced in the Kuzbass. The tubings are formed from coal and phenol-formaldehyde resins. Benzene sulfonic acid is used as hardening agent. Coal with grains up to 10 mm is used as filling agent. Five phenol-formaldehyde resins (SFZh-3032U, SF-142, SF-40K0, SFZh-3032NV, SFZh-3032) are evaluated as the basis for support production. The results are given in a table. Experiments show that SFZh-3032 resin is superior to other resins as a means of improving strength and mechanical parameters of the coal body in which workings are driven. It is noted that until now 10 km of resin reinforced coal tubing support have been constructed. Capacity of equipment producing the supports is 2.5 km/year. Resin reinforced tubing is economical: it need not be removed, can be mined together with coal seam, it reduces hazard of wall or floor swelling, increases haulage capacity of workings used for underground haulage 3 to 4 times, and improves safety of work for miners. (In Russian)

  2. The effect of high temperature sol-gel polymerization parameters on the microstructure and properties of hydrophobic phenol-formaldehyde/silica hybrid aerogels.

    Science.gov (United States)

    Seraji, Mohamad Mehdi; Sameri, Ghasem; Davarpanah, Jamal; Bahramian, Ahmad Reza

    2017-05-01

    Phenol-formaldehyde/silica hybrid aerogels with different degree of hydrophobicity were successfully synthesized via high temperature sol-gel polymerization. Tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) were used as precursor and co-precursor of the hydrophobic silica-based phase, respectively. The hydrolysis step of silica based sols were conducted by acid catalyzed reactions and HCl was used as hydrolysis catalyst. The chemical structure of prepared hybrid aerogels was characterized by Fourier Transform Infrared spectroscopy (FT-IR). The effect of MTES/TEOS proportion and catalyst content on the morphology and microstructure of samples were investigated by FE-SEM and C, Si mapping analysis. The acid catalyzed hydrolysis of TEOS and MTES sols leads to formation of a sol with primarily silica particles in the organic-inorganic hybrid sol and varying colloid growth mechanisms were occurred with change in MTES and HCl molar ratio. With the increasing of MTES content, the microstructure of samples changed from uniform colloidal network, core-shell structure to polymeric structure with a huge phase separation. The increasing of HCl mole fraction leads to smaller particle size. Moreover, the shrinkage of samples was decreased and water contact angles of the resulted aerogels were increased from 40 to 156.8° with the increases of MTES content.

  3. Catalytic Graphitization of Phenolic Resin

    Institute of Scientific and Technical Information of China (English)

    Mu Zhao; Huaihe Song

    2011-01-01

    The catalytic graphitization of thermal plastic phenolic-formaldehyde resin with the aid of ferric nitrate (FN) was studied in detail. The morphologies and structural features of the products including onion-like carbon nanoparticles and bamboo-shaped carbon nanotubes were investigated by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction and Raman spectroscopy measurements. It was found that with the changes of loading content of FN and residence time at 1000℃, the products exhibited various morphologies. The TEM images showed that bamboo-shaped carbon nanotube consisted of tens of bamboo sticks and onion-like carbon nanoparticle was made up of quasi-spherically concentrically closed carbon nanocages.

  4. 磺甲基酚醛树脂在水中的分散特性%Dispersion property of sulfomethyl phenol formaldehyde resin in water

    Institute of Scientific and Technical Information of China (English)

    李明远; 郭亚梅; 贺辉宗; 林梅钦; 彭勃; 郭继香

    2010-01-01

    测定磺甲基酚醛树脂水溶液流体力学直径和ζ电势,以此考察磺甲基酚醛树脂在水中的分散特性.结果表明:在去离子水中,当磺甲基酚醛树脂的质量浓度小于0.05 g/L时,体系分子聚集体的流体力学直径为105 nm,其表面带负电;当磺甲基酚醛树脂质量浓度高于0.05 g/L时,磺甲基酚醛树脂分子聚集体之间开始聚集,聚集体的流体力学直径随之增加;不同电解质对磺甲基酚醛树脂水溶液的聚沉作用不同,NaCl与CaCl2,MgCl2,AlCl3,Na2SO4聚沉值之比为1:0.032:0.66:0.00058:0.79;随NaCl质量浓度的增加,磺甲基酚醛树脂分子聚集体的流体力学直径随之增加,ζ电势随之降低;pH=3.0时聚集体流体力学直径最大,ζ电势绝对值最小.

  5. Microporosity development in phenolic resin-based mesoporous carbons for enhancing CO2 adsorption at ambient conditions

    Science.gov (United States)

    Choma, Jerzy; Jedynak, Katarzyna; Fahrenholz, Weronika; Ludwinowicz, Jowita; Jaroniec, Mietek

    2014-01-01

    Soft-templating method was used to prepare mesoporous carbons. The synthesis in the presence of hydrochloric and citric acids involved resorcinol and formaldehyde as carbon precursors and triblock copolymer Pluronic F127 as a template. The as-synthesized samples underwent carbonization in flowing nitrogen at various temperatures; namely 600 °C, 700 °C and 800 °C. Two routes were used to develop microporosity in the mesoporous carbons studied. The first one involved introduction of tetraethyl orthosilicate to the reaction system. After silica dissolution with NaOH, an increase in microporosity was observed. The second method, chemical activation with KOH at 700 °C, was explored as an alternative approach to create microporosity. It is noteworthy that the TEOS addition not only led to the development of microporosity but also to some improvement of mesoporosity. The post-synthesis KOH activation resulted in more significant increase in the microporosity as compared to the samples obtained by TEOS-assisted synthesis. The mesopore volume was somewhat lower for activated carbons as compared to that in mesoporous carbons. Both methods resulted in micro-mesoporous carbons with good adsorption properties; for instance, in the case of carbons prepared in the presence of TEOS, the best sample exhibited BET surface area of 1463 m2/g and the total pore volume of 1.31 cm3/g. For the KOH activated carbons the best adsorption parameters were as follows: the specific surface area = 1906 m2/g, and the total pore volume = 0.98 cm3/g. Both procedures used for microporosity development afforded carbons with good adsorption properties that can be useful for applications such as CO2 adsorption, air and water purification.

  6. Mesoporous Carbon-based Materials for Alternative Energy Applications

    Science.gov (United States)

    Cross, Kimberly Michelle

    /cm was measured for the composite without carbon nanotubes and the conductivity value improved by over an order of magnitude to 1 S/cm with the addition of 0.5 wt.% CNTs. Triggered by dispersion issues, the agglomeration of MWNTs during the drying process prevented each nanotube from being loaded over a maximum interfacial area. In order to improve the dispersion of carbon nanotubes within the carbon-silica network, electrospinning was explored as a method to improve the alignment of the carbon nanotubes. The electrospun fibers produced with the highest concentration of MWNTs at 1.0 wt.% produced the largest surface area and electrical conductivity values of 333.36 m2/g and 2.09 S/cm, respectively. Capacitance measurements were calculated to examine if improved conductivity results in higher capacitance values. The best capacitance performance was 148 F/g from a carbon-based mesoporous composite with 0.5 wt. % MWNTs in an aqueous electrolyte with a 2.0 mV/s scan rate. An 80% increase in capacitance occurs with the addition of 0.5 wt. % MWNTs. This is in the range of capacitance values produced by hierarchically ordered mesoporous-microporous carbons, reported at 180 F/g. Fibrous carbon tubes assembled from hydrofluoric acid etched perylenetetracarboxylic diimide bridged silsesquioxane (PDBS) were capable of hydrogen adsorption on the order of 1.3-2.5 wt. % at 77K. Lastly chemically activated phenol-formaldehyde resins produced microporous carbon with 1500 m3/g surface areas and pore sizes ranging from 0.3-0.5 nm, which has potential for asymmetric super-capacitor electrodes. Judicious control over the composition and pore structure of carbon-based nanocomposites can lead to improved performance of various alternative energy materials.

  7. Synthesis of mesoporous silica@Co-Al layered double hydroxide spheres: layer-by-layer method and their effects on the flame retardancy of epoxy resins.

    Science.gov (United States)

    Jiang, Shu-Dong; Bai, Zhi-Man; Tang, Gang; Song, Lei; Stec, Anna A; Hull, T Richard; Hu, Yuan; Hu, Wei-Zhao

    2014-08-27

    Hierarchical mesoporous silica@Co-Al layered double hydroxide (m-SiO2@Co-Al LDH) spheres were prepared through a layer-by-layer assembly process, in order to integrate their excellent physical and chemical functionalities. TEM results depicted that, due to the electrostatic potential difference between m-SiO2 and Co-Al LDH, the synthetic m-SiO2@Co-Al LDH hybrids exhibited that m-SiO2 spheres were packaged by the Co-Al LDH nanosheets. Subsequently, the m-SiO2@Co-Al LDH spheres were incorporated into epoxy resin (EP) to prepare specimens for investigation of their flame-retardant performance. Cone results indicated that m-SiO2@Co-Al LDH incorporated obviously improved fire retardant of EP. A plausible mechanism of fire retardant was hypothesized based on the analyses of thermal conductivity, char residues, and pyrolysis fragments. Labyrinth effect of m-SiO2 and formation of graphitized carbon char catalyzed by Co-Al LDH play pivotal roles in the flame retardance enhancement.

  8. Moisture insensitive adsorption of ammonia on resorcinol-formaldehyde resins.

    Science.gov (United States)

    Seredych, Mykola; Ania, Conchi; Bandosz, Teresa J

    2016-03-15

    Phenolic-formaldehyde resins aged at 85, 90 and 95°C were used as ammonia adsorbents at dynamic conditions in dry and moist air. To avoid pressure drops 10% bentonite was added as a binder. The initial and hybrid materials (before and after ammonia adsorption) were extensively characterized from the point of view of their porosity and surface chemistry. The results showed that the addition of the binder had various effects on materials' properties depending on the chemistry of their surface groups. When the phenolic acidic groups were predominant, the largest increase in surface acidity upon the addition of the binder was found. It was linked to the exfoliation of bentonite by polar moieties of the resins, which made acidic groups from aluminosilicate layers available for ammonia adsorption. On this sample, a relatively high amount of ammonia was strongly adsorbed in dry conditions. Insensitivity to moisture is a significant asset of ammonia adsorbents.

  9. Modeling the Effects of Velocity, Spin, Frictional Coefficient, and Impact Angle on Deflection Angle in Near-elastic Collisions of Phenolic Resin Spheres

    CERN Document Server

    Crown, S C

    2004-01-01

    A simple model is outlined to describe the collision of cast phenol-formaldehyde resin spheres such as the balls used in the parlor game of pocket billiards, based in part on the famous analysis of elastic collisions developed by Heinrich Hertz over 100 years ago. The analysis treats the normal and tangential components of the initial sphere's velocity independently as it collides with a stationary identical second sphere. The collective effects of these and other parameters on the trajectory of the second sphere are provided in the conclusions.

  10. Ethylated Urea - Ether - Modified Urea - Formaldehyde Resins,

    Directory of Open Access Journals (Sweden)

    Mathew Obichukwu EDOGA

    2006-07-01

    Full Text Available First, phenol - formaldehyde (PF and urea - formaldehyde (UFII resins were separately conventionally prepared in our laboratory. Also, UF resin synthesized from the acid modified synthesis procedure was synthesized in a purely acid medium of pH 1.0, FU molar ratio of 1.0 and at 50oC (one-stage acid modified-synthesis procedure. Subsequently, the UF resin II was modified during synthesis by incorporating ethylated urea-ether (EUER (i.e. UFIII and glycerol (GLYC (i.e. UFV cured with and without acid curing agent. The structural and physicochemical analyses of the various resin samples were carried out.The results showed that the unmodified UF resin (UF II synthesized in acid medium of pH 1.0, F/U molar ratio 1.0, and at 50oC, cured in absence of acid curing catalyst, showed features in their spectra which are consistent with a tri-, and/or tetra-substituted urea in the reaction to give a 3 - dimensional network cured UF resin. Modification of the UF resin(UF II with ethylated urea-ether and glycerol to produce UF resins III and respectively V prominently increased the absorbance of methylene and ether groups in the spectra which are consistent with increased hydrophobicity and improved hydrolytic stability. For the conventional UF resin (UF I, the only clear distinction between spectra for the UF resin II and UF resins (III/V is the presence of diminished peaks for methylene groups at 2.2 ppm. The relationship between the logarithmic viscosity of cured PF resin with time showed continuos dependence of viscosity with time during cure up to 70 minutes. Similar trends were shown by UF resins (III/V, cured in absence of acid catalyst. In contrast, the conventional UF resins I and UF IV (i.e. UF II cured with NH4CL showed abrupt discontinuity in viscosity with time just after about 20 minutes of cure.

  11. Production of renewable phenolic resins by thermochemical conversion of biomass: A review

    Energy Technology Data Exchange (ETDEWEB)

    Effendi, A.; Gerhauser, H.; Bridgwater, A.V. [Bio-Energy Research Group, Aston University, Birmingham B4 7ET (United Kingdom)

    2008-10-15

    This review covers the production and utilisation of liquids from the thermal processing of biomass and related materials to substitute for synthetic phenol and formaldehyde in phenol formaldehyde resins. These resins are primarily employed in the manufacture of wood panels such as plywood, MDF, particle-board and OSB. The most important thermal conversion methods for this purpose are fast pyrolysis and vacuum pyrolysis, pressure liquefaction and phenolysis. Many feedstocks have been tested for their suitability as sources of phenolics including hard and softwoods, bark and residual lignins. Resins have been prepared utilising either the whole liquid product, or a phenolics enriched fraction obtained after fractional condensation or further processing, such as solvent extraction. None of the phenolics production and fractionation techniques covered in this review are believed to allow substitution of 100% of the phenol content of the resin without impacting its effectiveness compared to commercial formulations based on petroleum derived phenol. This survey shows that considerable progress has been made towards reaching the goal of a price competitive renewable resin, but that further research is required to meet the twin challenges of low renewable resin cost and satisfactory quality requirements. Particular areas of concern are wood panel press times, variability of renewable resin properties, odour, lack of reactive sites compared to phenol and potential for increased emissions of volatile organic compounds. (author)

  12. Sulphonation of black liquor and its modification on sulphanilic acid-phenol-formaldehyde condensates%造纸黑液磺化及其改性氨基系减水剂的研究

    Institute of Scientific and Technical Information of China (English)

    季栋; 马宏明; 史以俊; 何明; 罗振扬

    2013-01-01

    鉴于造纸黑液产量巨大以及氨基系减水剂(SPF)存在的弊端,以造纸黑液为原料制取磺化木质素,并将其用于改性SPF制得HSPF系列减水剂.考察了磺化木质素的磺化度与分子量,并在吸附量、Zeta电位、净浆流动度和泌水等方面考察了HSPF性能以及与GSPF系列减水剂(由市售木质素磺酸钠改性SPF制得)的差异.研究结果表明:磺化木质素中引入较多磺酸基,其磺化度为0.821 mmol/g,分子量为22.97 kDa;HSPF在吸附能力、吸附量、Zeta电位、净浆流动度等方面均优于GSPF,这缘于磺化木质素更高的磺化度和更适宜的分子量;磺化木质素更大的分子量也造成HSPF泌水率更低.%Due to large amounts of black liquor and disadvantages of sulphanilic acid-phenol-formaldehyde condensates (SPF) , sulphonated lignin was prepared from black liquor and applied to the modification of SPF.A series of superplastici-zers called HSPF were produced.The sulphonation degree and molecular weight of sulphonated lignin were investigated, as well as the properties of HSPF and differences between GSPF (commercially available sodium lignosulphonate modified SPF) in various aspects of adsorption, adsorption capacity, zeta potential, paste fluidity, and bleeding.The results showed that considerable sulphonic groups were brought into sulphonated lignin, and the sulphonation degree and molecular weight of which were 0.821 mmol/g and 22.97 kDa, respectively.HSPF exhibited better performance on adsorption, adsorption capacity, zeta potential, and paste fluidity, resulting from the higher sulphonation degree and more appropriate molecular weight of sulphonated lignin.The lower bleeding rate of HSPF was caused by the larger molecular weight of sulphonated lignin.

  13. Preparation of phenol-formaldehyde type resin adhesive derived from liquefied products of walnut shell%核桃壳液化产物制备木材胶粘剂的研究

    Institute of Scientific and Technical Information of China (English)

    郑志锋; 邹局春; 刘本安; 汪蓉; 张宏健

    2007-01-01

    研究了核桃壳苯酚液化产物制备的酚醛树脂类木材胶粘剂及性能.结果表明,核桃壳经酸催化苯酚液化一段时间后,液化混合液的残渣率、游离苯酚和可被溴化物质量分数分别为22.11%、18.00%和33.10%,利用此液化混合液替代苯酚,所制备的酚醛树脂类胶粘剂能够满足混凝土模板用胶合板生产的要求.

  14. Flame Retardance of Phenol-formaldehyde Type Resin and Triphenyl Phosphate in Polycarbonate%热塑性酚醛树脂/磷酸三苯酯对PC阻燃性能的研究

    Institute of Scientific and Technical Information of China (English)

    肖春霞; 叶荣根; 赵旭忠; 蔡绪福; 彭菁

    2008-01-01

    分别合成了三种不同摩尔质量的热塑性酚醛树脂(PF),并将其分别与磷酸三苯酯(TPP)复配作为阻燃剂,制备了一系列的PF/TPP/PC阻燃体系,通过极限氧指数(LOI)、热失重(TGA)测试,研究了酚醛树脂摩尔质量、阻燃体系各组分配比、阻燃剂用量对聚碳酸酯(PC)阻燃性能的影响.结果表明:PF与仰对PC有良好的协同阻燃作用.当TPP/PF质量比为1:1,总添加量为20%时,PC的极限氧指数可达46%~52%.TGA曲线显示,在降解过程中酚醛树脂的加入能有效地抑制TPP的挥发,提高了PC在降解过程中的热稳定性并促使了更多炭层的形成.

  15. 糠醛对酚醛树脂固化反应动力学影响的研究%Study on Effect of Furfural on Curing Kinetics of Phenol Formaldehyde Resin

    Institute of Scientific and Technical Information of China (English)

    赵彩霞; 钟山; 邹国享; 张鑫; 宋艳; 李锦春

    2014-01-01

    采用DSC法研究不同升温速率下糖醛(FUF)/酚醛树脂(PF)体系的固化行为,结合Kissinger方程和Ozawa方程分析了不同含量的糠醛对FUF/PF固化反应动力学的影响.结果表明:随着糠醛的加入,固化反应温度略有降低;当糠醛用量超过5%时,酚醛树脂固化反应活化能迅速下降,由138 J/g降至115 J/g;随着温度升高,Ozawa指数下降,同时糠醛的加入也会降低Ozawa指数,但当糠醛含量达到7%时,在高温时Ozawa指数略微升高.

  16. Application of CO2 Cured Phenol-formaldehyde Resin Sand for Molten Steel%CO2硬化碱性酚醛树脂砂在铸钢生产中的应用

    Institute of Scientific and Technical Information of China (English)

    丛明

    2009-01-01

    CO2硬化碱性酚醛树脂砂既具有气硬冷芯盒的优点,又具有环保方面的优势.其初强度高,存放性好,流动性好;同时指出了CO2硬化碱性酚醛树脂砂应用中存在的问题,并提出建议.

  17. Investigation on curing mechanism of phenylphenol modified phenol-formaldehyde resin by means of DSC method%DSC对苯基苯酚改性酚醛树脂固化机理研究

    Institute of Scientific and Technical Information of China (English)

    张衍; 刘育建; 王井岗; 韩哲文

    2007-01-01

    采用DSC技术、Kissinger法对苯基苯酚改性酚醛树脂的固化过程进行了研究,得到放热峰顶活化能为169.3 kJ/mol,远大于普通酚醛树脂(约70 kJ/mol).理论近似凝胶温度、固化温度及后处理温度分别为414.5 K、448.9 K和483.9K.酚醛树脂的固化通常由化学反应控制和扩散控制两阶段组成.通过Ozawa法得到活化能与转化率(E-a)的变化关系表明,2种树脂固化历程存在明显差异.普通酚醛树脂固化反应进行到10%(a=10%),粘度迅速增大,反应转向扩散控制;而苯基苯酚改性酚醛树脂固化反应时粘度变化小,直至a=70%,才较快增长.这将有利于小分子的逃逸和各基团充分反应.同时高活化能也表明,反应形成了高键能的化学键,有利于提高树脂的残炭率和烧蚀性能.

  18. 腰果壳油改性摩擦材料用酚醛树脂的研究进展%The State of the Art of Friction Materials from Phenol Formaldehyde Resin Modified with Cashew Nut Shell Liquid

    Institute of Scientific and Technical Information of China (English)

    赵剑; 卫民; 蒋剑春

    2011-01-01

    腰果壳油是天然有机酚化合物,利用其改性摩擦材料用酚醛树脂具有改善材料力学性能和降低成本等优点,本文介绍了腰果壳油的组成及特性,简述了腰果壳油酚醛树脂的制备方法、改性途径及改性树脂用于摩擦材料方面的研究进展,进而展望了该树脂研究的前景.

  19. Synthesis of a boron modified phenolic resin

    Directory of Open Access Journals (Sweden)

    Aparecida M. Kawamoto

    2010-08-01

    Full Text Available Phenolic resin has long been used as matrix for composites mainly because of its flame retardant behavior and high char yield after pyrolysis, which results in a self supporting structure. The addition of ceramic powders, such as SiC and B4C, as fillers to the phenolic resin, results in better thermo-oxidative stability, but as drawbacks, it has poor homogeneity, adhesion and processing difficulties during molding of the composites. The addition of single elements, such as boron, silicon and phosphorus in the main backbone of the thermo-set resin is a new strategy to obtain special high performance resins, which results in higher mechanical properties, avoiding the drawbacks of simply adding fillers, which results in enhanced thermo-oxidative stability compared to conventional phenol-formaldehyde resins. Therefore, the product can have several applications, including the use as ablative thermal protection for thermo-structural composites. This work describes the preparation of a boron-modified phenolic resin (BPR using salicyl alcohol and boric acid. The reaction was performed in refluxing toluene for a period of four hours, which produced a very high viscosity amber resin in 90% yield.The final structure of the compound, the boric acid double, substituted at the hydroxyl group of the aromatic ring, was determined with the help of the Infrared Spectroscopy, ¹H-NMR, TGA-DSC and boron elemental analysis. The absorption band of the group B-O at 1349 cm ˉ¹ can be visualized at the FT-IR spectrum. ¹H-NMR spectra showed peaks at 4.97-5.04 ppm and 3.60-3.90 ppm assigned to belong to CH2OH groups from the alcohol. The elemental analysis was also performed for boron determination.The product has also been tested in carbon and silicon fibers composite for the use in thermal structure. The results of the tests showed composites with superior mechanical properties when compared with the conventional phenolic resin.

  20. Photocurable bioactive bone cement based on hydroxyethyl methacrylate-poly(acrylic/maleic) acid resin and mesoporous sol gel-derived bioactive glass.

    Science.gov (United States)

    Hesaraki, S

    2016-06-01

    This paper reports on strong and bioactive bone cement based on ternary bioactive SiO2-CaO-P2O5 glass particles and a photocurable resin comprising hydroxyethyl methacrylate (HEMA) and poly(acrylic/maleic) acid. The as-cured composite represented a compressive strength of about 95 MPa but it weakened during soaking in simulated body fluid, SBF, qua its compressive strength reached to about 20 MPa after immersing for 30 days. Biodegradability of the composite was confirmed by reducing its initial weight (~32%) as well as decreasing the molecular weight of early cured resin during the soaking procedure. The composite exhibited in vitro calcium phosphate precipitation in the form of nanosized carbonated hydroxyapatite, which indicates its bone bonding ability. Proliferation of calvarium-derived newborn rat osteoblasts seeded on top of the composite was observed during incubation at 37 °C, meanwhile, an adequate cell supporting ability was found. Consequently, it seems that the produced composite is an appropriate alternative for bone defect injuries, because of its good cell responses, high compressive strength and ongoing biodegradability, though more in vivo experiments are essential to confirm this assumption.

  1. Photocurable bioactive bone cement based on hydroxyethyl methacrylate-poly(acrylic/maleic) acid resin and mesoporous sol gel-derived bioactive glass

    Energy Technology Data Exchange (ETDEWEB)

    Hesaraki, S., E-mail: S-hesaraki@merc.ac.ir

    2016-06-01

    This paper reports on strong and bioactive bone cement based on ternary bioactive SiO{sub 2}-CaO-P{sub 2}O{sub 5} glass particles and a photocurable resin comprising hydroxyethyl methacrylate (HEMA) and poly(acrylic/maleic) acid. The as-cured composite represented a compressive strength of about 95 MPa but it weakened during soaking in simulated body fluid, SBF, qua its compressive strength reached to about 20 MPa after immersing for 30 days. Biodegradability of the composite was confirmed by reducing its initial weight (~ 32%) as well as decreasing the molecular weight of early cured resin during the soaking procedure. The composite exhibited in vitro calcium phosphate precipitation in the form of nanosized carbonated hydroxyapatite, which indicates its bone bonding ability. Proliferation of calvarium-derived newborn rat osteoblasts seeded on top of the composite was observed during incubation at 37 °C, meanwhile, an adequate cell supporting ability was found. Consequently, it seems that the produced composite is an appropriate alternative for bone defect injuries, because of its good cell responses, high compressive strength and ongoing biodegradability, though more in vivo experiments are essential to confirm this assumption. - Highlights: • Light cure cement based on SiO{sub 2}-CaO-P{sub 2}O{sub 5} glass and polymer-like matrix was formed. • The matrix includes poly(acrylic/maleic acid) and poly(hydroxyethyl methacrylate). • The cement is as strong as polymethylmethacrylate bone cement. • The cement exhibits apatite formation ability in simulated body fluid. • The cement is biodegradable and supports proliferation of osteoblastic cells.

  2. Characterization of the crosslinking reaction in high performance phenolic resins

    Science.gov (United States)

    Patel, Jigneshkumar; Zou, Guo Xiang; Hsu, Shaw Ling; university of massachusetts/Polymer science; Engineering Team

    In this study, a combination of thermal analysis, infrared spectroscopy (near and mid) in conjunction with low field NMR, was used to characterize the crosslinking reaction involving phenol formaldehyde resin and a crosslinking agent, Hexamethylenetetramine (HMTA). The strong hydrogen bonds in the resin and the completely crystalline HMTA (Tm = 280 °C) severely hamper the crosslinking process. Yet the addition of a small amount of plasticizer can induce a highly efficient crosslinking reaction to achieve the desired mechanical properties needed in a number of high performance organic-inorganic composites. The infrared spectroscopy clarifies the dissolution process of the crystalline crosslinker and the specific interactions needed to achieve miscibility of the reactants. The thermal analysis enabled us to follow the changing mobility of the system as a function of temperature. The low field NMR with the T1 inverse recovery technique allowed us to monitor the crosslinking process directly. For the first time, it is now possible to identify the functionality of the plasticizer and correlate the crosslinked structure achieved to the macroscopic performance needed for high performance organic-inorganic composites.

  3. Magnetic motive, ordered mesoporous carbons with partially graphitized framework and controllable surface wettability: preparation, characterization and their selective adsorption of organic pollutants in water

    Science.gov (United States)

    Zhang, Bin; Liu, Chen; Kong, Weiping; Qi, Chenze

    2016-06-01

    Magnetically active, ordered and stable mesoporous carbons with partially graphitized networks and controllable surface wettability (PR-Fe-P123-800 and PR-Ni-P123-800) have been synthesized through direct carbonization of Fe or Ni functionalized, and ordered mesoporous polymers at 800°C, which could be synthesized from self assembly of resol (phenol/formaldehyde) with block copolymer template (P123) in presence of Fe3+ or Ni2+, and hydrothermal treatment at 200°C. PR-Fe-P123-800 and PR-Ni-P123-800 possess ordered and uniform mesopores, large BET surface areas, good stabilities, controllable surface wettability and partially graphitized framework. The above structural characteristics result in their enhanced selective adsorption property and good reusability for organic pollutants such as RhB, p-nitrophenol and n-heptane in water, which could be easily regenerated through separation under constant magnetic fields and washing with ethanol solvent. The unique magnetically active and adsorptive property found in PR-Fe-P123-800 and PR-Ni-P123-800 will be very important for them to be used as efficient absorbents for removal of various organic pollutants in water.

  4. High capacity magnetic mesoporous carbon-cobalt composite adsorbents for removal of methylene green from aqueous solutions.

    Science.gov (United States)

    Dai, Mingzhi; Vogt, Bryan D

    2012-12-01

    Mesoporous carbons containing cobalt nanoparticles are synthesized by tri-or quad-constituent self assembly of Pluronic F127, phenol-formaldehyde oligomer (resol), cobalt acetylacetonate (acac), and optionally tetraethyl orthosilicate (TEOS, optional). Upon pyrolysis in N(2) atmosphere, the resol provides sufficient carbon yield to maintain the ordered structure, while decomposition of the Co(acac) yields cobalt nanoparticles. To provide increased surface area, the dispersed silicate from condensation of TEOS can be etched after carbonization to yield micropores, Without silica templated micropores, the surface area decreases as the cobalt content increases, but there is a concurrent increase in the volume-average pore diameter (BHJ) and a dramatic increase in the adsorption capacity of methylene green with the equilibrium adsorption capacity from 2 to 90 mg/g with increasing Co content. Moreover, the surface area and pore size of mesoporous composites can be dramatically increased by addition of TEOS and subsequent etching. These composites exhibit extremely high adsorption capacity up to 1151 mg/g, which also increases with increases in the Co content. Additionally, the inclusion of cobalt nanoparticles provides magnetic separation from aqueous suspension. The in situ synthesis of the Co nanoparticles yields to a carbon shell that can partially protect the Co from leaching in acidic media; after 96 h in 2 M HCl, the powders remain magnetic.

  5. Synthesis and Mechanism of Metal-Mediated Polymerization of Phenolic Resins

    Directory of Open Access Journals (Sweden)

    Zhao Yi

    2016-04-01

    Full Text Available Phenol-formaldehyde (PF resin is a high performance adhesive, but has not been widely developed due to its slow curing rate and high curing temperature. To accelerate the curing rate and to lower the curing temperature of PF resin, four types of metal-mediated catalysts were employed in the synthesis of PF resin; namely, barium hydroxide (Ba(OH2, sodium carbonate (Na2CO3, lithium hydroxide (LiOH, and zinc acetate ((CH3COO2Zn. The cure-acceleration effects of these catalysts on the properties of PF resins were measured, and the chemical structures of the PF resins accelerated with the catalysts were investigated by using Fourier transform infrared (FT-IR spectroscopy and quantitative liquid carbon-13 nuclear magnetic resonance (13C NMR. The results showed that the accelerated efficiency of these catalysts to PF resin could be ordered in the following sequence: Na2CO3 > (CH3COO2Zn > Ba(OH2 > LiOH. The catalysts (CH3COO2Zn and Na2CO3 increased the reaction activity of the phenol ortho position and the condensation reaction of ortho methylol. The accelerating mechanism of (CH3COO2Zn on PF resin is probably different from that of Na2CO3, which can be confirmed by the differences in the differential thermogravimetric (DTG curve and thermogravimetric (TG data. Compared to the Na2CO3-accelerated PF resin, the (CH3COO2Zn-accelerated PF resin showed different peaks in the DTG curve and higher weight residues. In the synthesis process, the catalyst (CH3COO2Zn may form chelating compounds (containing a metal-ligand bond, which can promote the linkage of formaldehyde to the phenolic hydroxyl ortho position.

  6. Preparation of free-standing high quality mesoporous carbon membranes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiqing [ORNL; Liang, Chengdu [ORNL; Dai, Sheng [ORNL; Mahurin, Shannon Mark [ORNL; Zhu, Qing [ORNL

    2010-01-01

    Flat-sheet mesoporous carbon membranes with uniform pore size (e.g., 6.4 nm) and controllable thickness were prepared by pyrolysis of polymeric composite films, which were formed by self-assembly of phenolic resin and block copolymer under acidic conditions. Hexamethylenetetramine was selected as a solid cross-linker to control the rheology of polymeric carbon precursors so that the flat-sheet polymeric films could undergo carbonization without deformation, ensuring the preparation of mesoporous carbon membranes on a large scale with high quality. Gas transport properties through these mesoporous carbon membranes are also reported.

  7. Mesoporous carbon materials

    Science.gov (United States)

    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.

  8. Multifunctional mesoporous silica catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Victor Shang-Yi; Tsai, Chih-Hsiang; Chen, Hung-Ting; Pruski, Marek; Kobayashi, Takeshi

    2015-03-31

    The present invention provides bifunctional silica mesoporous materials, including mesoporous silica nanoparticles ("MSN"), having pores modified with diarylammonium triflate and perfluoroaryl moieties, that are useful for the acid-catalyzed esterification of organic acids with organic alcohols.

  9. Synthesis of Mesoporous Carbon/Silica Using the Oligomer of Urea-formaldehyde Resin as Carbon Source and the Influence of Carbonization Temperature%脲醛树脂为碳源制备介孔碳/二氧化硅及碳化温度的影响

    Institute of Scientific and Technical Information of China (English)

    王颂; 牟鸣薇; 彭策; 李娃; 李凤云; 蔡强; 李恒德

    2013-01-01

    以低聚脲醛树脂为有机碳源前驱体、正硅酸乙酯(TEOS)为无机硅源、表面活性剂F127为模板剂,采用溶剂蒸发诱导自组装(EISA)合成有序介孔碳/二氧化硅杂化材料,研究了碳化温度对于介孔碳/二氧化硅杂化材料比表面积、孔径大小及分布的影响.采用X射线衍射仪(XRD)、热失重分析仪(TGA)、透射电子显微镜(TEM)、氮气吸/脱附等对制备样品进行了表征.结果表明,随着碳化温度的升高,各样品的晶面间距缩小,孔径数值也逐渐变小.碳化温度为850℃时,所得介孔碳/二氧化硅杂化材料孔径较小且孔径尺寸分布较集中.%Ordered mesoporous carbon/silica hybrid materials were synthesized using the oligomer of urea-formaldehyde resin as carbon source,triple copolymer surfactant F127 as template and tetraethylorthosilicate (TEOS) as silica source via evaporation induced self-assembly (ElSA)method.Through changing carbonization temperature,mesoporous carbon/silica hybrid samples with different BET surface areas and pore size distributions were obtained.The materials were characterized by X-ray diffraction (XRD),transmission electron microscope (TEM),Thermo Gravimetric Analyzer (TGA) and nitrogen adsorption-desorption analysis.The results showed that carbonization temperature would directly influence the pore structure.When the carbonization temperature is 850℃,the mesoporous carbon/silica hybrid material with perfect orderliness and narrow pore size distribution can be prepared.

  10. 苯酚-尿素-甲醛共缩聚树脂与酚醛树脂胶合性能对比研究%Comparative Study on Gluing Property between Phenol-urea-formaldehyde Co-condensed Resin and Phenol-formaldehyde Resin

    Institute of Scientific and Technical Information of China (English)

    张建; 李琴; 王波; 袁少飞

    2010-01-01

    利用自制PUF树脂,采用不同固体含量PUF树脂压制竹建筑模板,对PUF和PF压板进行对比试验,并对PUF树脂和PF树脂进行热重分析.结果表明:用PUF树脂压制的竹建筑模板胶合性能与目前企业所用PF树脂压制板材的胶合性能相当,浸胶固体含量以30%为宜,生产成本比相同固体含量的PF树脂降低约13.5%,热重分析显示两者的热固化行为相似.

  11. Photochromic mesoporous hybrid coatings

    Science.gov (United States)

    Raboin, L.; Matheron, M.; Gacoin, T.; Boilot, J.-P.

    2008-09-01

    Spirooxazine (SO) photochromic molecules were trapped in sol-gel matrices. In order to increase the colourability and improve mechanical properties of sol-gel photochromic films, we present an original strategy in which SO photochromic molecules were dispersed in mesoporous organized films using the impregnation technique. Well-ordered organosilicate mesoporous coatings with the 3D-hexagonal symmetry were prepared by the sol-gel technique. These robust mesoporous films, which contain high amounts of hydrophobic methyl groups at the pore surface, offer optimized environments for photochromic dyes dispersed by impregnation technique. After impregnation by a spirooxazine solution, the photochromic response is only slightly slower when compared with mesostructured or soft sol-gel matrices, showing that mesoporous organized hybrid matrix are good host for photochromic dyes. Moreover, the molecular loading in films is easily adjustable in a large range using multi-impregnation procedure and increasing the film thickness leading to coatings for optical switching devices.

  12. Fabrication and Characterization of Inorganic Silver and Palladium Nanostructures within Hexagonal Cylindrical Channels of Mesoporous Carbon

    Directory of Open Access Journals (Sweden)

    Jheng-Guang Li

    2014-06-01

    Full Text Available In this study, we prepared a mesoporous carbon with hexagonally packed mesopores through evaporation-induced self-assembly (EISA—with the diblock copolymer poly(ethylene oxide-b-ε-caprolactone (PEO-b-PCL as the template (EO114CL84, phenolic resin as the carbon precursor, hexamethylenetetramine (HMTA as the curing agent, and star octakis-PEO-functionalized polyhedral oligomeric silsesquioxane (PEO–POSS as the structure modifier—and subsequent carbonization. We then took the cylindrical mesoporous carbon as a loading matrix, with AgNO3 and Pd(NO32 as metal precursors, to fabricate Ag nanowire/mesoporous carbon and Pd nanoparticle/mesoporous carbon nanocomposites, respectively, through an incipient wetness impregnation method and subsequent reduction under H2. We used transmission electron microscopy, electron diffraction, small-angle X-ray scattering, N2 isotherm sorption experiment, Raman spectroscopy, and power X-ray diffraction to investigate the textural properties of these nanometal/carbon nanocomposites. Most notably, the Raman spectra of the cylindrical mesoporous carbon, Ag/mesoporous carbon, and Pd/mesoporous carbon revealed interesting phenomena in terms of the ratios of the intensities of the D and G bands (ID/IG, the absolute scattering intensities, and the positions of the D bands.

  13. Analysis of the Compounds from the BTEX Group, Emitted During Thermal Decomposition of Alkyd Resin

    Directory of Open Access Journals (Sweden)

    M. Kubecki

    2012-09-01

    Full Text Available Suitability of the given binding agent for the moulding sands preparation depends on the one hand on the estimation of technological properties of the sand and the mould made of it and the obtained casting quality and on the other hand on the assessment of this sand influence on the natural and working environment. Out of moulding sands used in the foundry industry, sands with organic binders deserve a special attention. These binders are based on synthetic resins, which ensure obtaining the proper technological properties and sound castings, however, they negatively influence the environment. If in the initial state these resins are not very dangerous for people and for the environment, thus under an influence of high temperatures they generate very harmful products, being the result of their thermal decomposition. Depending on the kind of the applied resin (phenol-formaldehyde, urea, furfuryl, urea–furfuryl, alkyd under an influence of a temperature such compounds as: furfuryl alcohol, formaldehyde, phenol, BTEX group (benzene, toluene, ethylbenzene, xylene, and also polycyclic aromatic hydrocarbons (PAH can be formed and released.The aim of the study was the development of the method, selection of analytical methods and the determination of optimal conditionsof formation compounds from the BTEX group. An emission of these components constitutes one of the basic criteria of the harmfulnessassessment of binders applied for moulding and core sands. Investigations were carried out in the specially designed set up for the thermal decomposition of organic substances in a temperature range: 5000C – 13000C at the laboratory scale. The object for testing was alkyd resin applied as a binding material for moulding sands. Within investigations the minimal amount of adsorbent necessary for the adsorption of compounds released during the decomposition of the resin sample of a mass app. 15 mg was selected. Also the minimal amount of solvent needed for

  14. 木质素超临界溶剂降解反应及其在酚醛树脂合成中的应用%REDUCTIVE DEGRADATION OF LIGNIN IN SUPERCRITICAL SOLVENT AND APPLICATION IN PHENOLIC RESIN SYNTHESIS

    Institute of Scientific and Technical Information of China (English)

    王明存

    2011-01-01

    The lignin was readily decomposed into phenol compounds via reductive liquefaction in supercritical ethanol media ( formic acid decomposed into hydrogen at reaction temperatures) , opening a promising opportunity to lignin-derived value-added aromatic compounds for highly possible application in phenol-formaldehyde resin production. The supercritical ethanol was the ideal reaction medium for lignin degradation, and the in situ generated hydrogen exactly promoted the decomposition reactions to smaller molecules via encapping the lignin radicals to terminate the further coupling and condensation. The liquefaction mechanism was radical thermal degradation. Some transition metal salts could catalyze the above lignin thermal decomposition, including nickel nitrate, cobalt nitrate and chloroplatinum acid. The yield of the lignin-degraded liquid increased with the increase of formic acid used in the ethanol solvent, while slightly deceased when the reaction temperature increased. The molecular weight of the lignin-derived liquid highly decreased with increase of the reaction temperature,e, g. At 350℃ the number average molecular weight was 143 while for the original lignin feedstock it was 588. The optimum reaction conditions are found to be ethanol-formic acid weight ratio at 1:1; lignin load at 10 wt% ; reaction temperature at 350℃ for 4 h. The lignin-derived phenols were characterized by CC-MS technique, and the liquefied product was mainly phenol derivatives with simple structures. Compared with the lignin, the bio-phenols possessed highly improved solubility and reactivity in phenol-formaldehyde synthesis. As the ideal replacement of industrial phenol, lignin-degraded bio-phenol was utilized readily in resol type phenolic resin production with a replacement higher than 50 wt%. The thermal stability was slightly decreased with the increased amount of lignin-derived biophenol in the phenolic resin formula. The results showed the effective reductive degradation of

  15. Epoxy resins.

    Science.gov (United States)

    Bray, P G

    1999-01-01

    Epoxy resins have an extraordinarily broad range of commercial applications, especially as protective surface coatings and adhesives. Epoxy resin systems include combinations of epoxy monomers, hardeners, reactive diluents, and/or a vast array of other additives. As a result, an epoxy resin system may have a number of chemical ingredients with the potential for attendant health hazards. Most, but not all, of these health hazards arise in the occupational setting. The most frequent adverse effects are irritation or allergic mechanisms involving the dermal and respiratory systems. Sensitization usually is caused by low molecular weight or short-chain compounds. This review discusses the diagnosis, treatment, and prevention of epoxy resin-related adverse health effects.

  16. Impact of film thickness on the morphology of mesoporous carbon films using organic-organic self-assembly.

    Science.gov (United States)

    Vogt, Bryan D; Chavez, Vicki L; Dai, Mingzhi; Arreola, M Regina Croda; Song, Lingyan; Feng, Dan; Zhao, Dongyuan; Perera, Ginusha M; Stein, Gila E

    2011-05-03

    Mesoporous polymer and carbon thin films are prepared by the organic-organic self-assembly of an oligomeric phenolic resin with an amphiphilic triblock copolymer template, Pluronic F127. The ratio of resin to template is selected such that a body-centered cubic (Im3m) mesostructure is formed in the bulk. However, well-ordered mesoporous films are not always obtained for thin films (body-centered cubic symmetry with a preferential orientation of the closest-packed (110) plane parallel to the substrate. Film thickness and initial composition of the carbonizable precursors in the template are critical factors in determining the morphology of mesoporous carbon films. These results provide insight into why difficulties have been reported in producing ultrathin ordered mesoporous carbon films using cooperative organic-organic self-assembly.

  17. Templating mesoporous zeolites

    DEFF Research Database (Denmark)

    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...

  18. Crystalline mesoporous metal oxide

    Institute of Scientific and Technical Information of China (English)

    Wenbo Yue; Wuzong Zhou

    2008-01-01

    Since the discovery of many types of mesoporous silicas, such as SBA-15, KIT-6, FDU-12 and SBA-16, porous crystalline transition metal oxides, such as Cr2O3, Co3O4, In2O3, NiO, CeO2, WO3, Fe2O3 and MnO2, have been synthesized using the mesoporous silicas as hard templates. Several synthetic methods have been developed. These new porous materials have high potential applications in catalysis, Li-ion rechargeable batteries and gas sensors. This article gives a brief review of the research of porous crystals of metal oxides in the last four years.

  19. Resin composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Peutzfeldt, Anne; Lussi, Adrian;

    2014-01-01

    OBJECTIVE: To investigate how the modulus of elasticity of resin composites influences marginal quality in restorations submitted to thermocyclic and mechanical loading. METHODS: Charisma, Filtek Supreme XTE and Grandio were selected as they were found to possess different moduli of elasticity...... of resin composite (p=0.81) on the quality of dentine margins was observed, before or after loading. Deterioration of all margins was evident after loading (p....008). CONCLUSIONS: The resin composite with the highest modulus of elasticity resulted in the highest number of gap-free enamel margins but with an increased incidence of paramarginal enamel fractures. CLINICAL SIGNIFICANCE: The results from this study suggest that the marginal quality of restorations can...

  20. Template Directed Synthesis and Characterization of Organic Mesoporous Polymers and their Adsorption Performance for Lysozyme

    Science.gov (United States)

    Sridhar, Manasa

    Three homologous series of MCFs with diverse pore topologies have been synthesized by symbiotic interplay of TMB/P123 (R1) and TEOS/P123 (R2) weight ratios in the initial microemulsion. It was found that the MCFs synthesized at R2 greater than the conventional value suffered significant lag in the mesopore volumes and areas at low concentrations of TMB. However, when R1 is increased beyond 1.0, the difference in the pore volumes and areas became negligible. Many key findings were reported through this study. TEM images revealed that the MCFs synthesized at higher values of R2 prematurely attained larger average pore sizes accompanied with portions displaying constricted worm-like mesostructures. Such bimodal mesophases are accounted by the swelling action of excess amounts of ethanol discharged due to the hydrolysis of increased amounts of TEOS present in the microemulsion along with partial TEOS dissolution in the hydrophobic PPO cores of the TMB/P123 micelles. MCFs synthesized at highest R2 value of 4.4 exhibits unique interconnected rod-like morphologies which are usually not observed for conventional MCFs. MCF produced using R1 = 2.5 and R2 = 3.0 exhibit bimodal mesophases consisting of polyhedral nanofoam-like textures along with regular spherical pores. USAXS results indicate wall thickness as large as 11 nm for MCFs produced at R2 =4.4. These MCFs of interesting mesostructures were employed as nanoscopic templates to produce Mesocellular Phenol Formaldehyde Foams (MPFFs) using vacuum-assisted incipient wetness impregnation technique. The nanocasted MPFFs show large pore volumes up to 1.4 cm3/g, BET surface areas more than 900 m2/g and large pore diameters in the range 27--99 nm depending on the MCF scaffold used. All the MPFFs showed faithful replication of the cavity sizes of their corresponding MCF parent templates. Stunningly, trimodal MPFFs resulted from the nanocasting of MCFs with R1 > 2.2. The resulting pore sizes were attributed to the original

  1. Environmental Protection Phenolic Resin Synthesis of Adhesive%环保型酚醛树脂胶粘剂的合成

    Institute of Scientific and Technical Information of China (English)

    李建锋

    2011-01-01

    The starch, formaldehyde, phenol as raw materials is introduced, in acidic conditions, hydrolysis of starch into D - glucose, glucose dehydration to generate HMF with phenol synthesis of phenolic resin adhesive, synthetic adhesive bond performance and is not modified compared to phenolic resin adhesive. There is not much change, and to reduce the amount of formaldehyde, to reduce costs. Intended to be the subject of partial replacement of starch synthesis of starch modified phenolic formaldehyde resin adhesive, through the study of formaldehyde in the amount of orthogonal test, starch dosage, pH and other factors affect the performance of samples to identify the optimum formulation.%通过对介绍以淀粉、甲醛、苯酚为原料,在酸性条件下,淀粉水解成D-葡萄糖,脱水生成羟甲基糠醛,与苯酚合成酚醛树脂胶粘剂,合成胶粘剂的粘结性能与未改性的酚醛树脂胶粘剂相比较,没有多大变化,而且减少甲醛的用量,降低了成本.本课题拟用淀粉部分取代甲醛合成淀粉改性酚醛树脂胶粘剂,通过正交试验研究甲醛用量、淀粉用量、pH等因素对样品性能的影响,找出最佳工艺配方.

  2. Review: Resin Composite Filling

    OpenAIRE

    Desmond Ng; Jimmy C. M. Hsiao; Keith C. T. Tong; Harry Kim; Yanjie Mai; Keith H. S. Chan

    2010-01-01

    The leading cause of oral pain and tooth loss is from caries and their treatment include restoration using amalgam, resin, porcelain and gold, endodontic therapy and extraction. Resin composite restorations have grown popular over the last half a century because it can take shades more similar to enamel. Here, we discuss the history and use of resin, comparison between amalgam and resin, clinical procedures involved and finishing and polishing techniques for resin restoration. Although resin ...

  3. Resin Catalyst Hybrids

    Institute of Scientific and Technical Information of China (English)

    S. Asaoka

    2005-01-01

    @@ 1Introduction: What are resin catalyst hybrids? There are typically two types of resin catalyst. One is acidic resin which representative is polystyrene sulfonic acid. The other is basic resin which is availed as metal complex support. The objective items of this study on resin catalyst are consisting of pellet hybrid, equilibrium hybrid and function hybrid of acid and base,as shown in Fig. 1[1-5].

  4. Breakthroughs in Mesoporous Composite Materials

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Mesoporous materials have attracted a great deal of attention due to their extremely high surface area, uniform and tunable pore structure (2-50nm in diameter), and have been investigated extensively since its invention. Unfortunately,their catalytic properties are far away from the expectation due to their amorphous and inert framework and poor stability. This research project is aimed at the design and synthesis of mesoporous-

  5. Engineered monodisperse mesoporous materials

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, R.S.; Small, J.H.; Lagasse, R.R.; Schroeder, J.L.; Jamison, G.M.

    1997-08-01

    Porous materials technology has developed products with a wide variety of pore sizes ranging from 1 angstrom to 100`s of microns and beyond. Beyond 15{angstrom} it becomes difficult to obtain well ordered, monodisperse pores. In this report the authors describe efforts in making novel porous material having monodisperse, controllable pore sizes spanning the mesoporous range (20--500 {angstrom}). They set forth to achieve this by using unique properties associated with block copolymers--two linear homopolymers attached at their ends. Block copolymers phase separate into monodisperse mesophases. They desired to selectively remove one of the phases and leave the other behind, giving the uniform monodisperse pores. To try to achieve this the authors used ring-opening metathesis polymerization to make the block copolymers. They synthesized a wide variety of monomers and surveyed their polymers by TGA, with the idea that one phase could be made thermally labile while the other phase would be thermally stable. In the precipitated and sol-gel processed materials, they determined by porosimetry measurements that micropores, mesopores, and macropores were created. In the film processed sample there was not much porosity present. They moved to a new system that required much lower thermal treatments to thermally remove over 90% of the labile phase. Film casting followed by thermal treatment and solvent extraction produced the desired monodisperse materials (based solely on SEM results). Modeling using Density Functional Theory was also incorporated into this project. The modeling was able to predict accurately the domain size and spacing vs. molecular weight for a model system, as well as accurate interfacial thicknesses.

  6. Synthesis and Characterization of Bimodal Mesoporous Silica

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiaofang; GUO Cuili; WANG Xiaoli; WU Yuanyuan

    2012-01-01

    Mesoporous silica with controllable bimodal pore size distribution was synthesized with cetyltrimethylammonium bromide (CTAB) as chemical template for small mesopores and silica gel as physical template for large mesopores.The structure of synthesized samples were characterized by Fourier transform infrared (FT-IR) spectroscopy,X-ray diffraction (XRD),scanning electron microscopy (SEM),transmission electron microscopy (TEM) and N2 adsorption-desorption measurements.The experimental results show that bimodal mesoporous silica consists of small mesopores of about 3 nm and large mesopores of about 45 nm.The small mesopores which were formed on the external surface and pore walls of the silica gel had similar characters with those of MCM-41,while large mesopores were inherited from parent silica gel material.The pore size distribution of the synthesized silica can be adjusted by changing the relative content of TEOS and silica gel or the feeding sequence of silica gel and NH4OH.

  7. Ordered mesoporous silica: microwave synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Fantini, M.C.A. [IF-USP, CP 66318, 05315-970, Sao Paulo, SP (Brazil)]. E-mail: mfantini@if.usp.br; Matos, J.R. [IQ-USP, CP 26077, 05599-970, Sao Paulo, SP (Brazil); Silva, L.C. Cides da [IQ-USP, CP 26077, 05599-970, Sao Paulo, SP (Brazil); Mercuri, L.P. [IQSC-USP, CP 780, 13560-970, Sao Carlos, SP (Brazil); Chiereci, G.O. [IQSC-USP, CP 780, 13560-970, Sao Carlos, SP (Brazil); Celer, E.B. [Department of Chemistry, Kent State University, Kent, OH 44240 (United States); Jaroniec, M. [Department of Chemistry, Kent State University, Kent, OH 44240 (United States)

    2004-09-25

    Ordered mesoporous silicas, FDU-1, synthesized by using triblock copolymer, EO{sub 39}BO{sub 47}EO{sub 39}, as template were hydrothermally treated in a microwave oven at 373 K for different periods of time. The structural and morphological properties of these silicas were investigated by X-ray diffraction and nitrogen adsorption and compared with those for the FDU-1 samples prepared by conventional hydrothermal treatment at 373 K. All samples were calcined at 813 K in N{sub 2} and air. This procedure succeeded in producing ordered cage-like mesoporous structures even after 15 min of the microwave treatment. The best sample was obtained after 60 min of the microwave treatment, which is reflected by narrow pore size distribution, uniform pore size entrances and thick mesopore walls. Longer time of the microwave treatment increased nonuniformity of the pore entrance sizes as evidenced by changes in the hysteresis loops of nitrogen adsorption isotherms.

  8. Research Update: Mesoporous sensor nanoarchitectonics

    Directory of Open Access Journals (Sweden)

    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.

  9. Mesoporous Silicate Materials in Sensing

    Directory of Open Access Journals (Sweden)

    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.

  10. Aligned mesoporous architectures and devices.

    Energy Technology Data Exchange (ETDEWEB)

    Brinker, C. Jeffrey; Lu, Yunfeng (University of California Los Angeles, Los Angeles, CA)

    2011-03-01

    This is the final report for the Presidential Early Career Award for Science and Engineering - PECASE (LDRD projects 93369 and 118841) awarded to Professor Yunfeng Lu (Tulane University and University of California-Los Angeles). During the last decade, mesoporous materials with tunable periodic pores have been synthesized using surfactant liquid crystalline as templates, opening a new avenue for a wide spectrum of applications. However, the applications are somewhat limited by the unfavorabe pore orientation of these materials. Although substantial effort has been devoted to align the pore channels, fabrication of mesoporous materials with perpendicular pore channels remains challenging. This project focused on fabrication of mesoporous materials with perpendicularly aligned pore channels. We demonstrated structures for use in water purification, separation, sensors, templated synthesis, microelectronics, optics, controlled release, and highly selective catalysts.

  11. Mesoporous Silicon-Based Anodes

    Science.gov (United States)

    Peramunage, Dharmasena

    2015-01-01

    For high-capacity, high-performance lithium-ion batteries. A new high-capacity anode composite based on mesoporous silicon is being developed. With a structure that resembles a pseudo one-dimensional phase, the active anode material will accommodate significant volume changes expected upon alloying and dealloying with lithium (Li).

  12. Magnetic mesoporous material for the sequestration of algae

    Science.gov (United States)

    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.

  13. [Radiopacity of composite resins].

    Science.gov (United States)

    Tamburús, J R

    1990-01-01

    The author studied the radiopacity of six composite resins, submitted to radiographic examination in standardized conditions, only with kilovoltage variations. Along with resins it was radiographed an aluminium penetrometer, to compare their optical densities. The results showed that kilovoltagem variations interfered in optical densities of the resins, being more pronounced in 50-55, 55-60 and 60-65 kilovoltages. Despite this, the relations of optical densities as compared with that of penetrometer steps kept unaltered most fo the kilovoltages used.

  14. RESEARCH ON IMPROVED EPOXY RESINS.

    Science.gov (United States)

    another ’million-modulus’ epoxy resin. Cast resin properties from a series of epoxy resins hardened with several aromatic diamines are reported, but these data are sufficient to advance only speculative conclusions. (Author)

  15. Mesoporous Silica: A Suitable Adsorbent for Amines

    Directory of Open Access Journals (Sweden)

    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.

  16. Mesoporous metal oxide graphene nanocomposite materials

    Science.gov (United States)

    Liu, Jun; Aksay, Ilhan A.; Kou, Rong; Wang, Donghai

    2016-05-24

    A nanocomposite material formed of graphene and a mesoporous metal oxide having a demonstrated specific capacity of more than 200 F/g with particular utility when employed in supercapacitor applications. A method for making these nanocomposite materials by first forming a mixture of graphene, a surfactant, and a metal oxide precursor, precipitating the metal oxide precursor with the surfactant from the mixture to form a mesoporous metal oxide. The mesoporous metal oxide is then deposited onto a surface of the graphene.

  17. Facile synthesis of hypercrosslinked resins via chloromethylation and continuous condensation of simple aryl molecules

    Indian Academy of Sciences (India)

    Xiaoyan Zhang; Qiu Jin; Libo Dai; Siguo Yuan

    2011-07-01

    A sort of non-polystyrene type hypercrosslinked resin was firstly synthesized through chloromethylation of simple aryl molecules (benzene, toluene, naphthalene, diphenyl), succedent continuous Friedel–Crafts alkylation polymerization and post-crosslinking reaction. The chemical and porous structures of these novel resins were characterized with BET, FT–IR and elementary analysis, respectively. The results showed that these novel adsorptive materials possessing abundant crosslinked networks had high specific surface areas (up to 1191.26 m2/g), large pore volumes (0.2–1.4 ml/g), narrow pore size distributions (mainly in the range of micropores and small mesopores).

  18. A Micelle Fusion-Aggregation Assembly Approach to Mesoporous Carbon Materials with Rich Active Sites for Ultrasensitive Ammonia Sensing.

    Science.gov (United States)

    Luo, Wei; Zhao, Tao; Li, Yuhui; Wei, Jing; Xu, Pengcheng; Li, Xinxin; Wang, Youwei; Zhang, Wenqing; Elzatahry, Ahmed A; Alghamdi, Abdulaziz; Deng, Yonghui; Wang, Lianjun; Jiang, Wan; Liu, Yong; Kong, Biao; Zhao, Dongyuan

    2016-09-28

    Nanostructured carbon materials have received considerable attention due to their special physicochemical properties. Herein, ordered mesoporous carbons (OMCs) with two-dimension (2D) hexagonal mesostructure and unique buckled large mesopores have successfully been synthesized via a micelle fusion-aggregation assembly method by using poly(ethylene oxide)-block-polystyrene (PEO-b-PS) diblock copolymers as a template and resorcinol-based phenolic resin as a carbon precursor. The obtained ordered mesoporous carbons possess unique fiber-like morphology, specific surface area of 571-880 m(2)/g, pore volume of 0.54 cm(3)/g and large mesopores (up to 36.3 nm) and high density of active sites (i.e., carboxylic groups) of 0.188/nm(2). Gas sensor based on the ordered mesoporous carbons exhibits an excellent performance in sensing NH3 at a low temperature with fast response (detection (<1 ppm), and good selectivity, due to the large pore sizes, high surface area and rich active sites in the carbon pore walls.

  19. Cellular membrane trafficking of mesoporous silica nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    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

  20. Ordered mesoporous silica materials with complicated structures

    KAUST Repository

    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.

  1. Hydrophilic and mesoporous SiO{sub 2}-TiO{sub 2}-SO{sub 3}H system for fuel cell membrane applications

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Lan-Young [Department of Fine Chemical Engineering and Chemistry, Chungnam National University, 220 Kung-dong, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Oh, Song-Yul [Department of Materials Science, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan); Matsuda, Atsunori, E-mail: matsuda@ee.tut.ac.j [Department of Materials Science, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan); Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan); Lee, Chang-Soo [Department of Chemical Engineering, Chungnam National University, 220 Kung-dong, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Kim, Dong-Pyo, E-mail: dpkim@cnu.ac.k [Department of Fine Chemical Engineering and Chemistry, Chungnam National University, 220 Kung-dong, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Graduate School of Analytical Science and Technology, Chungnam National University, 220 Kung-dong, Yuseong-gu, Daejeon 305-764 (Korea, Republic of)

    2011-03-30

    Graphical abstract: The composite films containing SiO{sub 2}-TiO{sub 2}-SO{sub 3}H resin additives, with strong water retention capabilities, showed superior proton conductivity, even at 120 {sup o}C and 25% RH, as well as a slightly improved current density at 30% RH and 70 {sup o}C, when compared to costly Nafion film. Display Omitted Research highlights: The hydrophilic and mesoporous SiO{sub 2}-TiO{sub 2}-SO{sub 3}H resins have a potential to be used as alternative membrane source materials in PEFCs. The sulfonation for hydrophilicity is conducted via simple chelating chemistry between catecholic groups and surface Ti ions. The proton conductivity of SiO{sub 2}-TiO{sub 2}-SO{sub 3}H composite films is superior to the commercial Nafion film. - Abstract: Hydrophilic and mesoporous sulfonated SiO{sub 2}-TiO{sub 2}-SO{sub 3}H systems as new additives for fuel cell electrolyte membranes are directly synthesized by the binary sol-gel reaction of TEOS-TiCl{sub 4} and consecutive sulfonation with a hydrophilic generator, dihydroxy-m-benzenedisulfonic acid disodium salt. The sulfonation approach makes use of the simple chelating chemistry between the catecholic groups (dihydroxy benzene) and surface Ti ions of the inorganic ordered mesoporous SBA-15 structure. The system is successfully employed in fuel cell membrane applications with a composite Nafion membrane mixed with a mesoporous hydrophilic resin additive, and reveals an obvious enhancement of the proton conductivity at low humidity and elevated temperatures. This improvement was attributed to the excellent water retention capability of the hydrophilic mesoporous resin.

  2. Improved conversion efficiency of amorphous Si solar cells using a mesoporous ZnO pattern

    Science.gov (United States)

    Go, Bit-Na; Kim, Yang Doo; suk Oh, Kyoung; Kim, Chaehyun; Choi, Hak-Jong; Lee, Heon

    2014-09-01

    To provide a front transparent electrode for use in highly efficient hydrogenated amorphous silicon (a-Si:H) thin-film solar cells, porous flat layer and micro-patterns of zinc oxide (ZnO) nanoparticle (NP) layers were prepared through ultraviolet nanoimprint lithography (UV-NIL) and deposited on Al-doped ZnO (AZO) layers. Through this, it was found that a porous micro-pattern of ZnO NPs dispersed in resin can optimize the light-trapping pattern, with the efficiency of solar cells based on patterned or flat mesoporous ZnO layers increased by 27% and 12%, respectively.

  3. General strategy for fabricating thoroughly mesoporous nanofibers

    KAUST Repository

    Hou, Huilin

    2014-12-03

    Recently, preparation of mesoporous fibers has attracted extensive attentions because of their unique and broad applications in photocatalysis, optoelectronics, and biomaterials. However, it remains a great challenge to fabricate thoroughly 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 proof of concept, the as-fabricated mesoporous TiO2 fibers exhibit much higher photocatalytic activity and stability than both the conventional solid counterparts and the commercially available P25. The abundant vapors released from the introduced foaming agents are responsible for the creation of pores with uniform spatial distribution in the spun precursor fibers. The present work represents a critically important step in advancing the electrospinning technique for generating mesoporous fibers in a facile and universal manner.

  4. 双马来酰亚胺改性苯并噁嗪树脂的力学性能及摩擦性能%Mechanical properties and friction properties of benzoxazine resin modified by bismaleimide

    Institute of Scientific and Technical Information of China (English)

    公超; 颜红侠; 李美丽; 马雷

    2012-01-01

    Benzoxazine(BOZ) resin as a new type thermosetting PF(phenol-formaldehyde resin), has many excellent properties, but its toughness and attrition-resistance were more poor. With AE-BMI(bismaleimide with allyl ether prepolymer) as modifier, an AE-BMI/BOZ modified resin was prepared, and its mechanics properties and friction properties were investigated. The results showed that the optimum AE-BMI contents had obviously toughening and strengthening functions in BOZ resin, and its attrition-resistance was obviously enhanced. The bend strength(125.53 Mpa) and impact strength (11.57 kJ/m2) of AE-BMI/BOZ modified system were 57% and 60% respectively more than those of pure BOZ system, and the attrition rate[18.50×10-6mm3/(N·m)] and friction factor(0.27) of AE-BMI/BOZ modified system were 15.6% and 50.6% respectively less than those of pure BOZ system when mass fraction of AE-BMI was 15%.%苯并噁嗪(BOZ)树脂作为一种新型的热固性PF(酚醛树脂),具有诸多优异性能,但其韧性和耐磨性较差.以AE-BMI(含烯丙基醚的双马来酰亚胺预聚体)为改性剂制备AE-BMI/BOZ改性树脂,并对其力学性能和摩擦性能进行了研究.结果表明:适量的AE-BMI对BOZ树脂具有明显的增韧增强作用,并且其耐磨性也明显提高;当w(AE-BMI)=15%时,AE-BMI/BOZ改性体系的弯曲强度(125.53 MPa)和冲击强度(11.57 kJ/m2)分别比纯BOZ体系提高了57%和60%,并且其摩擦因数(0.27)和磨损率[18.50×10-6 mm3/(N·m)]分别比纯BOZ体系降低了15.6%和50.6%.

  5. Biocompatibility of composite resins

    Directory of Open Access Journals (Sweden)

    Sayed Mostafa Mousavinasab

    2011-01-01

    Full Text Available Dental materials that are used in dentistry should be harmless to oral tissues, so they should not contain any leachable toxic and diffusible substances that can cause some side effects. Reports about probable biologic hazards, in relation to dental resins, have increased interest to this topic in dentists. The present paper reviews the articles published about biocompatibility of resin-restorative materials specially resin composites and monomers which are mainly based on Bis-GMA and concerns about their degradation and substances which may be segregated into oral cavity.

  6. Biocidal quaternary ammonium resin

    Science.gov (United States)

    Janauer, G. E.

    1983-01-01

    Activated carbon (charcoal) and polymeric resin sorbents are widely used in the filtration and treatment of drinking water, mainly to remove dissolved organic and inorganic impurities and to improve the taste. Earlier hopes that activated carbon might "disinfect' water proved to be unfounded. The feasibility of protecting against microbial infestation in charcoal and resin beds such as those to be incorporated into total water reuse systems in spacecraft was investigated. The biocidal effect of IPCD (insoluable polymeric contact disinfectants) in combination with a representative charcoal was assessed. The ion exchange resins (IPCD) were shown to adequately protect charcoal and ion exchange beds.

  7. Resin composite repair: Quantitative microleakage evaluation of resin-resin and resin-tooth interfaces with different surface treatments

    OpenAIRE

    Celik, Cigdem; Cehreli, Sevi Burcak; Arhun, Neslihan

    2015-01-01

    Objective: The aim was to evaluate the effect of different adhesive systems and surface treatments on the integrity of resin-resin and resin-tooth interfaces after partial removal of preexisting resin composites using quantitative image analysis for microleakage testing protocol. Materials and Methods: A total of 80 human molar teeth were restored with either of the resin composites (Filtek Z250/GrandioSO) occlusally. The teeth were thermocycled (1000×). Mesial and distal 1/3 parts of the res...

  8. Thermally conductive polymers

    Science.gov (United States)

    Byrd, N. R.; Jenkins, R. K.; Lister, J. L. (Inventor)

    1971-01-01

    A thermally conductive polymer is provided having physical and chemical properties suited to use as a medium for potting electrical components. The polymer is prepared from hydroquinone, phenol, and formaldehyde, by conventional procedures employed for the preparation of phenol-formaldehyde resins. While the proportions of the monomers can be varied, a preferred polymer is formed from the monomers in a 1:1:2.4 molar or ratio of hydroquinone:phenol:formaldehyde.

  9. Ecodesign of ordered mesoporous silica materials.

    Science.gov (United States)

    Gérardin, Corine; Reboul, Julien; Bonne, Magali; Lebeau, Bénédicte

    2013-05-07

    Characterized by a regular porosity in terms of pore size and pore network arrangement, ordered mesoporous solids have attracted increasing interest in the last two decades. These materials have been identified as potential candidates for several applications. However, more environmentally friendly and economical synthesis routes of mesoporous silica materials were found to be necessary in order to develop these applications on an industrial scale. Consequently, ecodesign of ordered mesoporous silica has been considerably developed with the objective of optimizing the chemistry and the processing aspects of the material synthesis. In this review, the main strategies developed with this aim are presented and discussed.

  10. Ordered mesoporous carbon coating on cordierite: Synthesis and application as an efficient adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Ying, E-mail: ywan@shnu.edu.cn [Key Laboratory of Resource Chemistry of Ministry of Education, Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China); Department of Chemistry, Shanghai Normal University, Shanghai 200234 (China); Cui, Xiangting; Wen, Zhentao [Department of Chemistry, Shanghai Normal University, Shanghai 200234 (China)

    2011-12-30

    Highlight: Black-Right-Pointing-Pointer Surfactant self-assembly of ordered mesoporous carbon coating on honeycomb cordierite. Black-Right-Pointing-Pointer Carbon coating with opened, hexagonally ordered pore arrays. Black-Right-Pointing-Pointer Honeycomb adsorbents for removal of p-chlorophenol. Black-Right-Pointing-Pointer The adsorbents exhibit large processing volume, and great advantages in reusability. - Abstract: Ordered mesoporous carbon coating on the honeycomb cordierite substrate has been prepared using low-polymerized phenolic resins as carbon sources and triblock copolymer F127 as the structure directing agent via the evaporation induced self-assembly route. The high-resolution scanning electron microscopy (HRSEM), transmission electron microscopy (TEM), and nitrogen sorption techniques prove the hexagonally ordered pore arrays of carbon coating on the cordierite. The honeycomb monolith adsorbents coated by ordered mesoporous carbons are directly used without any activation, and exhibit adsorption capacities for chlorinated organic pollutants in water with 200 mg/g for p-chlorophenol and 178 mg/g for p-chloroaniline (with respect to the net carbon coating), high adsorption ratio for low-concentration pollutants, large processing volumes and reusability. More than 200 repeated times can be achieved without obvious loss in both adsorption capacity and weight.

  11. Moderate Temperature Synthesis of Mesoporous Carbon

    KAUST Repository

    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.

  12. Mesoporous Silicon Far Infrared Filters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I proposal describes a novel method to make optical filters based on mesoporous silicon multilayers, for use at cold temperatures in the far infrared...

  13. Mesoporous Silicon Far Infrared Filters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I proposal describes a novel method to make optical filters based on mesoporous silicon multilayers, for use at cold temperatures in the far...

  14. The Synthesis and Evaluation of Filtrate Reducer SPX Resin of High temperature and Salt Resistivity%高温抗盐降滤失剂SPX树脂的合成与评价

    Institute of Scientific and Technical Information of China (English)

    江卫东; 何国军; 吴锰

    2001-01-01

    针对钻井液降滤失剂在使用过程中存在的高温增粘和遇到金属离子污染增粘的问题,从降滤失剂的分子结构出发,通过苯氧(基)乙酸与苯酚、甲醛等缩聚磺化,合成出磺化苯酚/苯氧(基)乙酸/甲醛树脂(简称SPX树脂)。试验研究表明, SPX树脂单独使用就具有抗饱和盐抗高温非增粘降滤失量的作用,含盐量在25%~36%之间时降滤失效果良好,含盐量低于25%时延长老化时间也有良好的降滤失效果;在加量合理时,钻井液老化前后表观粘度增加率小于10%。SPX树脂与SMK,SMC有良好的复配效果。%In consideration of increasing viscosity in filtrate reducer in drilling fluid under the conditions of high temperature and high contamination from metallic ions,sulphonate phenol and phenoxyacetic acid formaldehyde resin (simply call it SPX resin) is synthesized through polymerization and sulphonating using phenoxyacetic acid, phenol, formaldehyde etc. The result shows that when the SPX resin is used independently, it has the properties of high temperature resistance and saturated salt resistence for non-viscosified filtrate reducer and good efficiency of filtrate reducing. When salt content is from 25 % to 36 %,the filtrate reduction efficiency is the best,when the content is below 25% ,it is the best for lengthening aging time;when the content of SPX is reasonable, the apparent viscosity increase of the drilling fluid is less than 10% before and after its aging. The combination of SPX with SMK and SKC is good.

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

    KAUST Repository

    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.

  16. 40 CFR 721.7220 - Polymer of substituted phenol, formaldehyde, epichlorohydrin, and disubstituted benzene.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymer of substituted phenol... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.7220 Polymer of substituted phenol... subject to reporting. (1) The chemical substance identified generically as polymer of substituted...

  17. Adsorption of SO2 on bituminous coal char and activated carbon fiber prepared from phenol formaldehyde

    Science.gov (United States)

    DeBarr, Joseph A.; Lizzio, Anthony A.; Daley, Michael A.

    1996-01-01

    Carbon-based materials are used commercially to remove SO2 from coal combustion flue gases. Historically, these materials have consisted of granular activated carbons prepared from lignite or bituminous coal. Recent studies have reported that activated carbon fibers (ACFs) may have potential in this application due to their relatively high SO2 adsorption capacity. In this paper, a comparison of SO2 adsorption for both coal-based carbons and ACFs is presented, as well as ideas on carbon properties that may influence SO2 adsorption

  18. Preparation and Characterization of Carbon/Graphite Composites by Synthesizing Different Resins among Graphite Powders Using In-Situ Method%石墨粉体中原位合成不同树脂制备炭/石墨复合材料及其表征

    Institute of Scientific and Technical Information of China (English)

    陈建; 田建华; 李清静; 徐凤珍; 黄坤

    2011-01-01

    In order to combine the graphite powders and resin better, improve the performance of carbon product, phenol-formaldehyde resin(PFR)was in-situ synthesized in the graphite powders, which was used to prepare carbon/graphite (C/G) composites. The thermal performance of different resins prepared by in-situ synthesis was analyzed. The microstructure of the composites was observed. The performance of the C/G composites prepared with different kinds and contents resins was compared. The results show that the thermal stability performance of boron PFR(B-PFR) and o-cresol epoxy PFR(OCE-PFR) were better than thermoplastic phenolic (TP) PFR (TP-PFR) and thermosetting(TS) PFR (TS-PFR) in 0~900℃. The graphite granules and holes in B-PFR-C/G distributed more evenly than those in TP-PFR and TS~PFR after calcination. The comprehensive performance of B-PFR-C/G was better, the density, hardness and compressive strength were 1.58g·cm^-3, 47. 5 HS and 31.8 MPa when the resin content was 35wt%.%为了使石墨粉体与树脂能够更好地结合,改善碳素制品的性能,首先在石墨粉体中原位合成不同酚醛树脂,再制备成炭/石墨(C/G)复合材料;分析了原位合成不同树脂的热性能,观察了炭/石墨复合材料的微观结构,比较了不同种类、含量的树脂制备炭/石墨复合材料的性能。结果表明:在0~900℃内,原位合成硼改性酚醛树脂(B-PFR)和邻甲环氧酚醛树脂(OCE-PFR)的热稳定性能较热塑性酚醛树脂(TFLPFR)和热固性酚醛树脂(TS-PFR)的好;原位合成的树脂经焙烧后,B-PFR-C/G中石墨颗粒和孔隙分布较均匀,其次为T

  19. Influence of synthesis conditions and mesoporous structures on the gold nanoparticles supported on mesoporous silica hosts

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byunghwan [Korea Institute of Industrial Technology, ChonAn, Korea; Ma, Zhen [ORNL; Zhang, Zongtao [ORNL; Park, Chulhwan [Kwangwoon University; Dai, Sheng [ORNL

    2009-01-01

    Loading gold on mesoporous materials via different methods has been actively attempted in the literature, but the knowledge about the influences of synthesis details and different mesoporous structures on the size and thermal stability of gold nanoparticles supported on mesoporous hosts is still limited. In this study, Au/HMS, Au/MCM-41, Au/MCM-48, Au/SBA-15, and Au/SBA-16 samples were prepared by modifying a variety of mesoporous silicas by amine ligands followed by loading HAuCl4 and calcination. The influences of different amine ligands ((3-aminopropyl)triethoxysilane versus N-[3-(trimethoxysilyl)propyl]ethylenediamine), solvents (water versus ethanol), calcination temperatures (200 or 550 C), and mesoporous structures on the size of supported gold nanoparticles were systematically investigated employing nitrogen adsorption-desorption measurement, X-ray diffraction (XRD), diffuse reflectance UV-vis spectroscopy, and transmission electron microscopy (TEM). Interestingly, while big and irregular gold particles situate on MCM-48 with bicontinuous three-dimensional pore structure and relatively small pore size (2.4 nm) upon calcination at 550 C, homogeneous and small gold nanoparticles maintain inside SBA-15 with one-dimensional pore structure and relatively big pore size (6.8 nm). Apparently, the pore structure and pore size of mesoporous silica hosts play a key role in determining the size and thermal stability of the supported gold nanoparticles. Our results may provide some useful clues for the rational design of supported metal catalysts by choosing suitable mesoporous hosts.

  20. Nanostructured Mesoporous Silicas for Bone Tissue Regeneration

    Directory of Open Access Journals (Sweden)

    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.

  1. Supramolecular-templated synthesis of mesoporous silica-zirconia nanocomposite

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Mesoporous SiO2-ZrO2 nanocomposite was successfully prepared by using supramolecular triblock copolymer as the template through evaporation-induced self-assembly approach. The textural and structural properties were characterized by X-ray diffraction, nitrogen adsorption analysis, and transmission electron microscope.Comparison between pure mesoporous silica and mesoporous silica-zirconia nanocomposite was also presented in this work. The surface area, pore size, and pore volume decreased as the Zr doping in the mesoporous silica framework. But the obtained nanocomposite maintained the cubic Im3m-type mesoporous structure.

  2. System for removing contaminants from plastic resin

    Science.gov (United States)

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2010-11-23

    A resin recycling system that produces essentially contaminant-free synthetic resin material in an environmentally safe and economical manner. The system includes receiving the resin in container form. A grinder grinds the containers into resin particles. The particles are exposed to a solvent in one or more solvent wash vessels, the solvent contacting the resin particles and substantially removing contaminants on the resin particles. A separator is used to separate the resin particles and the solvent. The resin particles are then placed in solvent removing element where they are exposed to a solvent removing agent which removes any residual solvent remaining on the resin particles after separation.

  3. Preparation and characterization of mesoporous indium oxide

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yi-zhe; CHENG Zhi-xuan; PAN Qing-yi; DONG Xiao-wen; ZHANG Jian-cheng; PAN Ling-li

    2009-01-01

    Indium oxide nanocrystals with mesoporous structure were successfully synthesized by using triblock copolymer as a template,and characterized by thermogravimetry-differential scanning calorimeter (TG-DSC),X-ray powder diffraction (XRD),high resolution transmission electron microscopy (HRTEM) and N2 adsorption.A high EO/PO ratio is thought to be the key point to prepare mesoporous In2O3.The results show that the average pore diameter of the products is 6 nm,the BET surface area is 54.78 m2/g,and the adsorbing pore volume is 0.345 cm3/g.After comparing with normal indium oxide nanoparticles by BET test,mesoporous indium oxide demonstrates a large difference in adsorbing pore volume and average pore diameters from normal ones.

  4. Synthesis and characterization of mesoporous hydrocracking catalysts

    Science.gov (United States)

    Munir, D.; Usman, M. R.

    2016-08-01

    Mesoporous catalysts have shown great prospective for catalytic reactions due to their high surface area that aids better distribution of impregnated metal. They have been found to contain more adsorption sites and controlled pore diameter. Hydrocracking, in the presence of mesoporous catalyst is considered more efficient and higher conversion of larger molecules is observed as compared to the cracking reactions in smaller microporous cavities of traditional zeolites. In the present study, a number of silica-alumina based mesoporous catalysts are synthesized in the laboratory. The concentration and type of surfactants and quantities of silica and alumina sources are the variables studied in the preparation of catalyst supports. The supports prepared are well characterized using SEM, EDX, and N2-BET techniques. Finally, the catalysts are tested in a high pressure autoclave reactor to study the activity and selectivity of the catalysts for the hydrocracking of a model mixture of plastics comprising of LDPE, HDPE, PP, and PS.

  5. Flame Retardant Epoxy Resins

    Science.gov (United States)

    Thompson, C. M.; Smith, J. G., Jr.; Connell, J. W.; Hergenrother, P. M.; Lyon, R. E.

    2004-01-01

    As part of a program to develop fire resistant exterior composite structures for future subsonic commercial aircraft, flame retardant epoxy resins are under investigation. Epoxies and their curing agents (aromatic diamines) containing phosphorus were synthesized and used to prepare epoxy formulations. Phosphorus was incorporated within the backbone of the epoxy resin and not used as an additive. The resulting cured epoxies were characterized by thermogravimetric analysis, propane torch test, elemental analysis and microscale combustion calorimetry. Several formulations showed excellent flame retardation with phosphorous contents as low as 1.5% by weight. The fracture toughness of plaques of several cured formulations was determined on single-edge notched bend specimens. The chemistry and properties of these new epoxy formulations are discussed.

  6. Paramagnetic epoxy resin

    Directory of Open Access Journals (Sweden)

    E. C. Vazquez Barreiro

    2017-01-01

    Full Text Available This work illustrates that macrocycles can be used as crosslinking agents for curing epoxy resins, provided that they have appropriate organic functionalities. As macrocycles can complex metal ions in their structure, this curing reaction allows for the introduction of that metal ion into the resin network. As a result, some characteristic physical properties of the metallomacrocycle could be transferred to the new material. The bisphenol A diglycidyl ether (BADGE, n = 0 and hemin (a protoporphyrin IX containing the Fe(III ion, and an additional chloride ligand have been chosen. The new material has been characterized by differential scanning calorimetry (DSC, thermogravimetric analysis (TGA, Fourier Transform Infrared (FT-IR, Nuclear Magnetic Resonance (NMR, Transmission Electron Microscopy (TEM, and magnetic susceptibility measurements. Fe(III remains in the high-spin state during the curing process and, consequently, the final material exhibits the magnetic characteristics of hemin. The loss of the chlorine atom ligand during the cure of the resin allows that Fe(III can act as Lewis acid, catalyzing the crosslinking reactions. At high BADGE n = 0/hemin ratios, the formation of ether and ester bonds occurs simultaneously during the process.

  7. Location of laccase in ordered mesoporous materials

    Directory of Open Access Journals (Sweden)

    Álvaro Mayoral

    2014-11-01

    Full Text Available The functionalization with amine groups was developed on the SBA-15, and its effect in the laccase immobilization was compared with that of a Periodic Mesoporous Aminosilica. A method to encapsulate the laccase in situ has now been developed. In this work, spherical aberration (Cs corrected scanning transmission electron microscopy combined with high angle annular dark field detector and electron energy loss spectroscopy were applied to identify the exact location of the enzyme in the matrix formed by the ordered mesoporous solids.

  8. Basic Functionalization of Hexagonal Mesoporous Silica

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    3-Aminopropyltricthoxysilanc (AM), 3-cthyldiaminopropyltrimcthoxysilane (ED) and 3-piperazinylpropyltriethoxysilanc (PZ), were used to chemically couple with the silanol groups of calcined hexagonal and hexagonal-like mesoporous silica SBA-3 and HMS, respectively, to produce functionalised alkaline mesoporous materials. The inerease in the dosage of organosilanes, or in reaction temperature, or in the humidity (i.e., water content) of support, is favorable to the grafting of functional molecules on the surface. When functionalization conditions are the same, the order of loadings on SBA-3 and DDA-HMS is ED>AM>PZ. However, on ODA-HMS, the loading of AM is similar to that of ED.

  9. Adsorptive desulfurization of diesel with mesoporous aluminosilicates

    Institute of Scientific and Technical Information of China (English)

    TANG Huang; LI Wang-Liang; LIU Qing-Fen; GUAN Li-Li; SONG Jia-Qing; XING dian-Min; LIU Hui-Zhou

    2009-01-01

    Mesoporous aluminosilicates (MAS) bearing microporous zeolite units and mesoporous structures were synthesized by the hydrothermal method. Adsorptive desulfurization ability of model oil and hy-drotreated diesel was studied. The effects of template concentration, crystalization time and calcination time were investigated. The desulfurization ability of adsorbents was improved by transitional metal ion-exchanging. The adsorptive desulfurization of diesel was carried out on a fixed-bed system. The results show that the adsorptive capacity is MASMCM-41NaY. The improvement of desulfurization ability of MAS by Cu+ is more significant than that of Ag+.

  10. Location of laccase in ordered mesoporous materials

    Energy Technology Data Exchange (ETDEWEB)

    Mayoral, Álvaro [Laboratorio de Microscopias Avanzadas, Instituto de Nanociencia de Aragon, Universidad de Zaragoza, Edificio I - D, Mariano Esquillor, 50018 Zaragoza (Spain); Gascón, Victoria; Blanco, Rosa M.; Márquez-Álvarez, Carlos; Díaz, Isabel, E-mail: idiaz@icp.csic.es [Instituto de Catálisis y Petroleoquímica, CSIC, c/Marie Curie 2, 28049 Madrid (Spain)

    2014-11-01

    The functionalization with amine groups was developed on the SBA-15, and its effect in the laccase immobilization was compared with that of a Periodic Mesoporous Aminosilica. A method to encapsulate the laccase in situ has now been developed. In this work, spherical aberration (C{sub s}) corrected scanning transmission electron microscopy combined with high angle annular dark field detector and electron energy loss spectroscopy were applied to identify the exact location of the enzyme in the matrix formed by the ordered mesoporous solids.

  11. Orientation specific deposition of mesoporous particles

    Directory of Open Access Journals (Sweden)

    Tomas Kjellman

    2014-11-01

    Full Text Available We present a protocol for a facile orientation specific deposition of plate-like mesoporous SBA-15 silica particles onto a surface (mesopores oriented normal to surface. A drop of an aqueous dispersion of particles is placed on the surface and water vaporizes under controlled relative humidity. Three requirements are essential for uniform coverage: particle dispersion should not contain aggregates, a weak attraction between particles and surface is needed, and evaporation rate should be low. Aggregates are removed by stirring/sonication. Weak attraction is realized by introducing cationic groups to the surface. Insight into the mechanisms of the so-called coffee stain effect is also provided.

  12. Microstructure and application of mesoporous nanosize zirconia

    Institute of Scientific and Technical Information of China (English)

    LIU Xinmei; YAN Zifeng; G.Q.Lu

    2004-01-01

    The mesoporous nanoscale zircoina zeolite was firstly synthesized via solid state -- Structure directing method without addition of any stabilizer. The sample bears lamellar or worm pore structures, relatively high surface area compared with that reported. The mesoporous nanosize structure can also resist higher calcination temperature. The introduction of above zirconia to the catalyst of methanol synthesis dedicates the nanosize particle size to the catalyst, which significantly changes the physical structure and electronic effect of the catalyst. The catalyst shows higher catalytic activity and selectivity to methanol. The active sites for methanol synthesis are demonstrated over various catalysts in this paper.

  13. Dry PMR-15 Resin Powders

    Science.gov (United States)

    Vannucci, Raymond D.; Roberts, Gary D.

    1988-01-01

    Shelf lives of PMR-15 polymides lengthened. Procedure involves quenching of monomer reactions by vacuum drying of PRM-15 resin solutions at 70 to 90 degree F immediately after preparation of solutions. Absence of solvent eliminates formation of higher esters and reduces formation of imides to negligible level. Provides fully-formulated dry PMR-15 resin powder readily dissolvable in solvent at room temperature immediately before use. Resins used in variety of aerospace, aeronautical, and commercial applications.

  14. Resin regeneration device for condensate desalter

    Energy Technology Data Exchange (ETDEWEB)

    Segawa, Yoshihiro [Toshiba Engineering Co. Ltd., Kawasaki, Kanagawa (Japan); Hirose, Yuki

    1998-07-28

    The present invention provides a resin regeneration device for a condensate desalter of a nuclear power plant. Namely, both anionic and cationic exchange resins are supplied in a mixed state from a forwarding water desalting tower to an anionic resin regeneration tower. In the anionic resin generation tower, the resin is once separated to an anionic exchange region layer, a mixed resin layer and an cationic exchange resin layer in this order from the upper portion by water injected from a stirring water injection tube disposed at the bottom. Then, water is injected from a developing water injection tube disposed at the lower portion of the mixed resin layer to develop the cationic exchange resin layer and the mixed resin layer to the upper portion of the cationic resin regeneration tower. Subsequently, the amount of the injection of the developing water is reduced to such a flow rate that only the anionic exchange resin is precipitated. Then, a cationic exchange resin layer is formed at the upper portion and an anion exchange resin layer is formed at the lower portion of the developing water injection tube of the cationic resin regeneration tower. The anionic exchange resin is transferred to the anionic exchange resin regeneration tower in this state. According to the present invention, the mixed resin layer can be separated to anionic and cationic exchange resins easily and reliably. (I.S.)

  15. Recovery of silica from electronic waste for the synthesis of cubic MCM-48 and its application in preparing ordered mesoporous carbon molecular sieves using a green approach

    Science.gov (United States)

    Liou, Tzong-Horng

    2012-07-01

    The electronics industry is one of the world's fastest growing manufacturing industries. However, e-waste has become a serious pollution problem. This study reports the recovery of e-waste for preparing valuable MCM-48 and ordered mesoporous carbon for the first time. Specifically, this study adopts an alkali-extracted method to obtain sodium silicate precursors from electronic packaging resin ash. The influence of synthesis variables such as gelation pH, neutral/cationic surfactant ratio, hydrothermal treatment temperature, and calcination temperature on the mesophase of MCM-48 materials is investigated. Experimental results confirm that well-ordered cubic MCM-48 materials were synthesized in strongly acidic and strongly basic media. The resulting mesoporous silica had a high surface area of 1,317 m2/g, mean pore size of about 3.0 nm, and a high purity of 99.87 wt%. Ordered mesoporous carbon with high surface area (1,715 m2/g) and uniform pore size of CMK-1 type was successfully prepared by impregnating MCM-48 template using the resin waste. The carbon structure was sensitive to the sulfuric acid concentration and carbonization temperature. Converting e-waste into MCM-48 materials not only eliminates the disposal problem of e-waste, but also transforms industrial waste into a useful nanomaterial.

  16. Mesoporous Transition Metal Oxides for Supercapacitors

    Science.gov (United States)

    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.

  17. Mesoporous Transition Metal Oxides for Supercapacitors

    Directory of Open Access Journals (Sweden)

    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.

  18. Supra-amphiphilic transparent mesoporous silica coating

    Institute of Scientific and Technical Information of China (English)

    MA Jin; YANG Zhenglong; QU Xiaozhong; YANG Zhenzhong

    2006-01-01

    Transparent mesoporous silica coatings were achieved by conventional sol-gel process. The obtained coatings display permanent supraamphiphilicity, transparent appearance and good wetting property with very fast spread rate. Incorporation of functional materials such as crystalline titania nanoparticles into the coatings was also carried out without affecting the transparency and supraamphiphilicity.

  19. Controllable synthesis of nitrogen-doped hollow mesoporous carbon spheres using ionic liquids as template for supercapacitors

    Science.gov (United States)

    Chen, Aibing; Li, Yunqian; Liu, Lei; Yu, Yifeng; Xia, Kechan; Wang, Yuying; Li, Shuhui

    2017-01-01

    We have demonstrated a facile and controllable synthesis of monodispersed nitrogen-doped hollow mesoporous carbon spheres (N-HMCSs) using resorcinol/formaldehyde resin as a carbon precursor, tetraethyl orthosilicate as a structure-assistant agent, ionic liquids (ILs) as soft template, partial carbon sources, and nitrogen sources. The sizes and the architectures including hollow and yolk-shell of resultant carbon spheres can be efficiently controlled through the adjustment of the content of ILs. Alkyl chain length of the ILs also has an important effect on the formation of N-HMCSs. With proper alkyl chain length and content of ILs, the resultant N-HMCSs show monodispersed hollow spheres with high surface areas (up to 1158 m2 g-1), large pore volumes (up to 1.70 cm3 g-1), and uniform mesopore size (5.0 nm). Combining the hollow mesoporous structure, high porosity, large surface area, and nitrogen functionality, the as-synthesized N-HMCSs have good supercapacitor performance with good capacitance (up to 159 F g-1) and favorable capacitance retention (88% capacitive retention after 5000 cycles).

  20. [Acrylic resin removable partial dentures

    NARCIS (Netherlands)

    Baat, C. de; Witter, D.J.; Creugers, N.H.J.

    2011-01-01

    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of

  1. Prototype of low thermal expansion materials: fabrication of mesoporous silica/polymer composites with densely filled polymer inside mesopore space.

    Science.gov (United States)

    Kiba, Shosuke; Suzuki, Norihiro; Okawauchi, Yoshinori; Yamauchi, Yusuke

    2010-09-03

    A prototype of novel low thermal expansion materials using mesoporous silica particles is demonstrated. Mesoporous silica/polymer composites with densely filled polymer inside the mesopore space are fabricated by mechanically mixing both organically modified mesoporous silica and epoxy polymer. The mesopores are easily penetrated by polymers as a result of the capillary force during the mechanical composite processing. Furthermore, we propose a new model of polymer mobility restriction using mesoporous silica with a large pore space. The robust inorganic frameworks covering the polymer effectively restrict the polymer mobility against thermal energy. As a result, the degree of total thermal expansion of the composites is drastically decreased. From the mass-normalized thermal mechanical analysis (TMA) charts of various composites with different amounts of mesoporous silica particles, it is observed that the coefficient of thermal expansion (CTE) values gradually increase with an increase of the polymer amount outside the mesopores. It is proven that the CTE values in the range over the glass-transition temperatures (T(g)) are perfectly proportional to the outside polymer amounts. Importantly, the Y-intercept of the relation equation obtained by a least-square method is the CTE value and is almost zero. This means that thermal expansion does not occur if no polymers are outside the mesopores. Through such a quantative discussion, we clarify that only the outside polymer affects the thermal expansion of the composites, that is, the embedded polymers inside the mesopores do not expand at all during the thermal treatment.

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

    Science.gov (United States)

    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 Molecular Sieves as Supports for Metathesis Catalysts

    Science.gov (United States)

    Balcar, Hynek; Cejka, Jirí

    Mesoporous molecular sieves represent a new family of inorganic oxides with regular nanostructure, large surface areas, large void volumes, and narrow pore size distribution of mesopores. These materials offer new possibilities for designing highly active and selective catalysts for olefin metathesis and metathesis polymerization. Siliceous sieves MCM-41, MCM-48, SBA-15, and organized mesoporous alumina (OMA) were used as supports for preparation of new molybdenum and rhenium oxide catalysts, as well as for heterogenization of well-defined homogeneous catalysts.

  4. Electrical Relaxation in ULTEM® and ULTEM® Containing Mesoporous Silica

    Science.gov (United States)

    Turo, Andrew; Edmondson, Charles E.; Lomax, Joseph F.; Bendler, John T.; Fontanella, John J.; Wintersgill, Mary C.

    2008-08-01

    Mesoporous silica has been added to Ultem® 1000 polyetherimide using solution casting. The mesoporous silica that was added was either uncoated or coated with polystyrene. Audio frequency dielectric relaxation studies were then carried out over the temperature range 5.5 to 550 K. Several interesting results were obtained. First, the uncoated mesoporous silica caused essentially no change in the relaxation spectrum of pure Ultem®. The polystyrene coated mesoporous silica caused rather large changes. The most striking example is the introduction of a new relaxation. This relaxation occurs at about 150 K and 1000 Hz as showing in fig. 1 via the open circles.

  5. Functionalized Mesoporous Silica Membranes for CO2 Separation Applications

    Directory of Open Access Journals (Sweden)

    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. 21 CFR 177.1500 - Nylon resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Nylon resins. 177.1500 Section 177.1500 Food and... Repeated Use Food Contact Surfaces § 177.1500 Nylon resins. The nylon resins listed in paragraph (a) of... packaging food, subject to the provisions of this section: (a) The nylon resins are manufactured...

  7. 21 CFR 177.2440 - Polyethersulfone resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethersulfone resins. 177.2440 Section 177.2440... Components of Articles Intended for Repeated Use § 177.2440 Polyethersulfone resins. Polyethersulfone resins... the purpose of this section, polyethersulfone resins are: (1)...

  8. 21 CFR 177.1655 - Polysulfone resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polysulfone resins. 177.1655 Section 177.1655 Food... of Single and Repeated Use Food Contact Surfaces § 177.1655 Polysulfone resins. Polysulfone resins... purpose of this section, polysulfone resins are: (1)...

  9. 21 CFR 178.3930 - Terpene resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Terpene resins. 178.3930 Section 178.3930 Food and... and Production Aids § 178.3930 Terpene resins. The terpene resins identified in paragraph (a) of this... the terpene resins identified in paragraph (b) of this section may be safely used as components...

  10. Biocompatibility, degradability, bioactivity and osteogenesis of mesoporous/macroporous scaffolds of mesoporous diopside/poly(l-lactide) composite

    OpenAIRE

    Liu, Zhulin; Ji, Jiajin; Tang, Songchao; Qian, Jun; Yan, Yonggang; Yu, Baoqing; Su, Jiacan; Wei, Jie

    2015-01-01

    Bioactive mesoporous diopside (m-DP) and poly(l-lactide) (PLLA) composite scaffolds with mesoporous/macroporous structure were prepared by the solution-casting and particulate-leaching method. The results demonstrated that the degradability and bioactivity of the mesoporous/macroporous scaffolds were significantly improved by incorporating m-DP into PLLA, and that the improvement was m-DP content-dependent. In addition, the scaffolds containing m-DP showed the ability to neutralize acidic deg...

  11. Indirect resin composites

    Directory of Open Access Journals (Sweden)

    Nandini Suresh

    2010-01-01

    Full Text Available Aesthetic dentistry continues to evolve through innovations in bonding agents, restorative materials, and conservative preparation techniques. The use of direct composite restoration in posterior teeth is limited to relatively small cavities due to polymerization stresses. Indirect composites offer an esthetic alternative to ceramics for posterior teeth. This review article focuses on the material aspect of the newer generation of composites. This review was based on a PubMed database search which we limited to peer-reviewed articles in English that were published between 1990 and 2010 in dental journals. The key words used were ′indirect resin composites,′ composite inlays,′ and ′fiber-reinforced composites.′

  12. Contact allergy to epoxy resin

    DEFF Research Database (Denmark)

    Bangsgaard, Nannie; Thyssen, Jacob Pontoppidan; Menné, Torkil

    2012-01-01

    . Objectives. To evaluate the prevalence of contact allergy to epoxy resin monomer (diglycidyl ether of bisphenol A; MW 340) among patients with suspected contact dermatitis and relate this to occupation and work-related consequences. Patients/methods. The dataset comprised 20 808 consecutive dermatitis...... in an educational programme. Conclusion. The 1% prevalence of epoxy resin contact allergy is equivalent to reports from other countries. The high occurrence of epoxy resin exposure at work, and the limited use of protective measures, indicate that reinforcement of the law is required....

  13. Recycle of silicate waste into mesoporous materials.

    Science.gov (United States)

    Kim, Jung Ho; Kim, Minwoo; Yu, Jong-Sung

    2011-04-15

    Template synthesis of porous carbon materials usually requires selective removal of template silica from the carbon/silica composites. It not only involves waste of valuable chemicals, but also poses significant environmental concerns including high waste treatment cost. Recycling of silicates released from such nanocasting methods is successfully performed for the first time to regenerate valuable mesoporous MCM and SBA type silica materials, which will not only help in saving valuable chemicals, but also in decreasing chemical waste, contributing in improvement of our environmental standards. This approach can thus improve cost effectiveness for the mass production of nanostructured carbon and others utilizing silica directed nanocasting method by recycling otherwise silicate waste into highly desirable valuable mesoporous silica.

  14. SYNTHESIS AND COATING OF ORDERED MESOPOROUS SILICA

    Institute of Scientific and Technical Information of China (English)

    Wei Guo; Guangsheng Luo; Yujun Wang

    2003-01-01

    1,3,5-trimethyl benzene (TMB) was used as organic swelling agent in O/W emulsions to template ultra-large mesoporous materials using the hydrothermal method. The silicas with well-defined mesopores and hydrothermally robust framework were characterized by X-ray diffraction, transmission electron microscopy and BET surface area analysis. The influence of the quantity of TMB during preparation was studied. It has been found that the TMB/CTAB ratio must be controlled for producing high pore volume materials. Polysulfone (PSU), as the usual extraction agent, was coated on the silicas with the solvent evaporation method to produce a solid separation medium. The adsorptivity and the surface area of the coated MCM were determined: 10% PSU coated MCM adsorbed twice as much phenol as the uncoated material, reaching 0.5 mg/g silica. It was found that the surface area of the coated material decreased rapidly with an increase of the PSU loading.

  15. Mesoporous silica nanoparticles for active corrosion protection.

    Science.gov (United States)

    Borisova, Dimitriya; Möhwald, Helmuth; Shchukin, Dmitry G

    2011-03-22

    This work presents the synthesis of monodisperse, mesoporous silica nanoparticles and their application as nanocontainers loaded with corrosion inhibitor (1H-benzotriazole (BTA)) and embedded in hybrid SiOx/ZrOx sol-gel coating for the corrosion protection of aluminum alloy. The developed porous system of mechanically stable silica nanoparticles exhibits high surface area (∼1000 m2·g(-1)), narrow pore size distribution (d∼3 nm), and large pore volume (∼1 mL·g(-1)). As a result, a sufficiently high uptake and storage of the corrosion inhibitor in the mesoporous nanocontainers was achieved. The successful embedding and homogeneous distribution of the BTA-loaded monodisperse silica nanocontainers in the passive anticorrosive SiOx/ZrOx film improve the wet corrosion resistance of the aluminum alloy AA2024 in 0.1 M sodium chloride solution. The enhanced corrosion protection of this newly developed active system in comparison to the passive sol-gel coating was observed during a simulated corrosion process by the scanning vibrating electrode technique (SVET). These results, as well as the controlled pH-dependent release of BTA from the mesoporous silica nanocontainers without additional polyelectrolyte shell, suggest an inhibitor release triggered by the corrosion process leading to a self-healing effect.

  16. Mesoporous metal catalysts formed by ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Continuous microwave flow synthesis of mesoporous hydroxyapatite

    Energy Technology Data Exchange (ETDEWEB)

    Akram, Muhammad; Alshemary, Ammar Z.; Goh, Yi-Fan; Wan Ibrahim, Wan Aini [Department of Chemistry, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor (Malaysia); Lintang, Hendrik O. [Centre for Sustainable Nanomaterials (CSNano), Ibnu Sina Institute for Scientific and Industrial Research, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor (Malaysia); Hussain, Rafaqat, E-mail: rafaqat@kimia.fs.utm.my [Centre for Sustainable Nanomaterials (CSNano), Ibnu Sina Institute for Scientific and Industrial Research, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor (Malaysia)

    2015-11-01

    We have successfully used continuous microwave flow synthesis (CMFS) technique for the template free synthesis of mesoporous hydroxyapatite. The continuous microwave flow reactor consisted of a modified 2.45 GHz household microwave, peristaltic pumps and a Teflon coil. This cost effective and efficient system was exploited to produce semi-crystalline phase pure nano-sized hydroxyapatite. Effect of microwave power, retention time and the concentration of reactants on the phase purity, degree of crystallinity and surface area of the final product was studied in detail. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to study the phase purity and composition of the product, while transmission electron microscopy (TEM) was used to study the effect of process parameters on the morphology of hydroxyapatite. The TEM analysis confirmed the formation of spherical particles at low microwave power; however the morphology of the particles changed to mesoporous needle and rod-like structure upon exposing the reaction mixture to higher microwave power and longer retention time inside the microwave. The in-vitro ion dissolution behavior of the as synthesized hydroxyapatite was studied by determining the amount of Ca{sup 2+} ion released in SBF solution. - Highlights: • Continuous microwave flow synthesis method was used to prepare hydroxyapatite. • Increase in microwave power enhanced the degree of crystallinity. • TEM images confirmed the presence of mesopores on the surface of HA.

  18. Mesoporous Silica from Rice Husk Ash

    Directory of Open Access Journals (Sweden)

    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

  19. Polymer/mesoporous metal oxide composites

    Science.gov (United States)

    Ver Meer, Melissa Ann

    Understanding the nature of the interfacial region between an organic polymer matrix and an inorganic filler component is essential in determining how this region impacts the overall bulk properties of the organic/inorganic hybrid composite material. In this work, polystyrene was used as the model polymer matrix coupled with silica-based filler materials to investigate the nature of structure-property relationships in polymer composites. Initial work was conducted on synthesis and characterization of colloidal and mesoporous silica particles melt blended into the polystyrene matrix. Modification of the interface was accomplished by chemically bonding the silica particles with the polystyrene chains through polymerization from the particle surface via atom transfer radical polymerization. High molecular weight polystyrene chains were formed and bulk test samples were evaluated with increased thermal stability of the grafted polymer composite system versus equivalent melt blended polymer composites. Polymer grafting was also conducted from the internal pores of mesoporous silica, further improving the thermal stability of the composite system without degrading dynamic mechanical properties. Characterization of the polymer composites was conducted with gel permeation chromatography, transmission electron microscopy, thermogravimetric analysis and dynamic mechanical analysis. It was also discovered during the polystyrene-silica composite studies that amorphous polystyrene can possess a less mobile phase, evident in a second peak of the loss tangent (tan delta). The long annealing times necessitated by the mesoporous silica composites were replicated in as received polystyrene. This new, less mobile phase is of particular interest in determining the mobility of polymer chains in the interfacial region.

  20. Facile synthesis of gradient mesoporous carbon monolith based on polymerization-induced phase separation

    Science.gov (United States)

    Xu, Shunjian; Luo, Yufeng; Zhong, Wei; Xiao, Zonghu; Luo, Yongping; Ou, Hui; Zhao, Xing-Zhong

    2014-06-01

    In this paper, a gradient mesoporous carbon (GMC) monolith derived from the mixtures of phenolic resin (PF) and ethylene glycol (EG) was prepared by a facile route based on polymerization-induced phase separation under temperature gradient (TG). A graded biphasic structure of PF-rich and EG-rich phases was first formed in preform under a TG, and then the preform was pyrolyzed to obtain the GMC monolith. The TG is mainly induced by the thermal resistance of the preferential phase separation layer at high temperature region. The pore structure of the monolith changes gradually along the TG direction. When the TG varies from 58°C to 29°C, the pore size, apparent porosity and specific surface area of the monolith range respectively from 18 nm to 83 nm, from 32% to 39% and from 140.5 m2/g to 515.3 m2/g. The gradient porous structure of the monolith is inherited from that of the preform, which depends on phase separation under TG in the resin mixtures. The pyrolysis mainly brings about the contraction of the pore size and wall thickness as well as the transformation of polymerized PF into glassy carbon.

  1. Bending characteristics of resin concretes

    Directory of Open Access Journals (Sweden)

    Ribeiro Maria Cristina Santos

    2003-01-01

    Full Text Available In this research work the influence of composition and curing conditions in bending strength of polyester and epoxy concrete is analyzed. Various mixtures of resin and aggregates were considered in view of an optimal combination. The Taguchi methodology was applied in order to reduce the number of tests, and in order to evaluate the influence of various parameters in concrete properties. This methodology is very useful for the planning of experiments. Test results, analyzed by this methodology, shown that the most significant factors affecting bending strength properties of resin concretes are the type of resin, resin content and charge content. An optimal formulation leading to a maximum bending strength was achieved in terms of material parameters.

  2. Epoxy hydantoins as matrix resins

    Science.gov (United States)

    Weiss, J.

    1983-01-01

    Tensile strength and fracture toughness of castings of the hydantoin resins cured with methylenedianiline are significantly higher than MY 720 control castings. Water absorption of an ethyl, amyl hydantoin formulation is 2.1 percent at equilibrium and Tg's are about 160 C, approximately 15 deg below the final cure temperature. Two series of urethane and ester-extended hydantoin epoxy resins were synthesized to determine the effect of crosslink density and functional groups on properties. Castings cured with methylenedianiline or with hexahydrophthalic anhydride were made from these compounds and evaluated. The glass transition temperatures, tensile strengths and moduli, and fracture toughness values were all much lower than that of the simple hydantoin epoxy resins. Using a methylene bishydantoin epoxy with a more rigid structure gave brittle, low-energy fractures, while a more flexible, ethoxy-extended hydantoin epoxy resin gave a very low Tg.

  3. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel;

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  4. EPOXY RESIN TOUGHENED BY THERMOPLASTICS

    Institute of Scientific and Technical Information of China (English)

    FU Zengli; SUN Yishi

    1989-01-01

    Two kinds of tough ductile heatresisting thermoplastic, namely bisphenol A polysulfone (PSF) and polyethersulfone (PES) were used to toughen thermoset epoxy resin. A systematic study on the relationship between the molecular weight and the terminal group of the thermoplastic modifier and the fracture toughness of the modified resin was carried out. The morphology of PSF modified epoxy resin was surveyed. With the same kind of PSF the structure of the epoxy resin and the toughening effect of PSF was also investigated. The fractography of PSF, particle modified epoxy was examined in detail with SEM. The contribution of every possible energy absorption process has been discussed. Crack pinning mechanism seems to be the most important toughening mechanism for tough ductile thermoplastic PSF particle modified epoxy system.

  5. Karakteristik Komposit Resin Berkemampuan Mengalir

    Directory of Open Access Journals (Sweden)

    Bambang Irawan

    2015-10-01

    Full Text Available The use of resin composites as posterior restoratives has markedly increased over the past decade. The patients demand for better esthetics, concerns related to possible mercury toxicity from amalgam and improvements in resin composite materials have significantly contributed the popularity of these materials. Early problems related to composites included excessive wear, less of anatomic form, post operative sensitivity, secondary caries and marginal leakage. Marginal adaptation still remains an unavoidable problem for composite restoration, especially at the gingival wall of cervical or Class II restoration. In an attempt to improve marginal sealing, many techniques and lining materials have been designed. To reduce stress generated by polymerization shrinkage, applying and curing of resin composites in layers is often recommended. Using a thick adhesive layer or low-viscosity resin may, due to its elastic properties, serve as a flexible intermediate layer and compensate for the polymerization stress created in resin composite. Flowable composites were created by retaining the same small particle size of traditional hybrid composite but reducing the filler content and allowing the increased resin to reduce the viscosity of the mixture. Flowable composites were introduced in 1996 as liners, fissure sealants and also in tunnel preparations. They have been suggested for Class I, II, III and V cavity restorations, preventive resin restorations and composite, porcelain and amalgam repairing. Their usage as a liner under high filled resins in posterior restorations has been shown to improve the adaptation of composites and effectively achieve clinically acceptable results. This article attempts to give a broad characteristics of different types of flowable composites. 

  6. Karakteristik Komposit Resin Berkemampuan Mengalir

    OpenAIRE

    Bambang Irawan

    2015-01-01

    The use of resin composites as posterior restoratives has markedly increased over the past decade. The patients demand for better esthetics, concerns related to possible mercury toxicity from amalgam and improvements in resin composite materials have significantly contributed the popularity of these materials. Early problems related to composites included excessive wear, less of anatomic form, post operative sensitivity, secondary caries and marginal leakage. Marginal adaptation still remains...

  7. New Low Cost Resin Systems

    Science.gov (United States)

    2006-05-31

    DGEBA ). 30 % of the epoxy groups of RDGE were reacted with the dihydroxyl acid and resulted 3.2 wt% phosphorous and a new epoxide equivalent weight...of 207. Adducts were also made with DGEBA and the dihydroxyl phosphorous based acid but resulted in a substantial increased viscosity and therefore...70 wt% with a standard DGEBA resin, this material accelerated the epoxy reaction too much to make a VaRTM processable resin. Due to the processing

  8. Generalized synthesis of mesoporous shells on zeolite crystals

    KAUST Repository

    Han, Yu

    2010-12-30

    A simple and generalized synthetic approach is developed for creating mesoporous shells on zeolite crystals. This method allows for the tailoring of thickness, pore size, and composition of the mesoporous shell, and can be applied to zeolites of various structures, compositions, and crystal sizes. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Morphology control of ordered mesoporous carbons for high capacity lithium sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Joerg David

    2011-06-07

    The focus of this thesis concerns the morphology control of ordered mesoporous carbon (OMC) materials. Ordered mesoporous carbons with diverse morphologies, that are thin films, fibers - embedded in anodic alumina membranes and free-standing - or spherical nanoparticles, have been successfully prepared by soft-templating procedures. The mechanisms of structure formation and processing were investigated with in-situ SAXS measurements and their application in high capacity lithium-sulfur batteries was successfully tested in cooperation with Guang He and Linda Nazar from the University of Waterloo in Canada. The Li-S batteries receive increasing attention due to their high theoretical energy density which is 3 to 5 times higher than from lithium-ion batteries. For this type of battery the specific pore volume is crucial for the content of the active component (sulfur) in the cathode and therefore correlates with the capacity and gravimetric energy density of the battery. At first, mesoporous thin films with 2D-hexagonal structure were obtained through organic-organic self-assembly of a preformed oligomeric resol precursor and the triblock copolymer template Pluronic P123. The formation of a condensed-wall material through thermopolymerization of the precursor oligomers resulted in mesostructured phenolic resin films. Subsequent decomposition of the surfactant and partial carbonization were achieved through thermal treatment in inert atmosphere. The films were crack-free with tunable homogenous thicknesses, and showed either 2D-hexagonal or lamellar mesostructure. An additional, yet unknown 3D-mesostructure was also found. In the second part, cubic and circular hexagonal mesoporous carbon phases in the confined environment of tubular anodic alumina membrane (AAM) pores were obtained by self-assembly of the mentioned resol precursor and the triblock copolymer templates Pluronic F127 or P123, respectively. Casting and solvent-evaporation were also followed by

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Biodegradation-tunable mesoporous silica nanorods for controlled drug delivery.

    Science.gov (United States)

    Park, Sung Bum; Joo, Young-Ho; Kim, Hyunryung; Ryu, WonHyoung; Park, Yong-il

    2015-05-01

    Mesoporous silica in the forms of micro- or nanoparticles showed great potentials in the field of controlled drug delivery. However, for precision control of drug release from mesoporous silica-based delivery systems, it is critical to control the rate of biodegradation. Thus, in this study, we demonstrate a simple and robust method to fabricate "biodegradation-tunable" mesoporous silica nanorods based on capillary wetting of anodic aluminum oxide (AAO) template with an aqueous alkoxide precursor solution. The porosity and nanostructure of silica nanorods were conveniently controlled by adjusting the water/alkoxide molar ratio of precursor solutions, heat-treatment temperature, and Na addition. The porosity and biodegradation kinetics of the fabricated mesoporous nanorods were analyzed using N2 adsorption/desorption isotherm, TGA, DTA, and XRD. Finally, the performance of the mesoporous silica nanorods as drug delivery carrier was demonstrated with initial burst and subsequent "zero-order" release of anti-cancer drug, doxorubicin.

  12. Iron oxide nanoparticles stabilized inside highly ordered mesoporous silica

    Indian Academy of Sciences (India)

    A Bhaumik; S Samanta; N K Mal

    2005-11-01

    Nanosized iron oxide, a moderately large band-gap semiconductor and an essential component of optoelectrical and magnetic devices, has been prepared successfully inside the restricted internal pores of mesoporous silica material through in-situ reduction during impregnation. The samples were characterized by powder XRD, TEM, SEM/EDS, N2 adsorption, FT-IR and UV–visible spectroscopies. Characterization data indicated well-dispersed isolated nanoclusters of (Fe2O3),` within the internal surface of 2D-hexagonal mesoporous silica structure. No occluded Fe/Fe2O3 crystallites were observed at the external surface of the mesoporous silica nanocomposites. Inorganic mesoporous host, such as hydrophilic silica in the pore walls, directs a physical constraint necessary to prevent the creation of large Fe2O3 agglomerates and enables the formation of nanosized Fe2O3 particles inside the mesopore.

  13. A highly ordered cubic mesoporous silica/graphene nanocomposite

    Science.gov (United States)

    Lee, Chang-Wook; Roh, Kwang Chul; Kim, Kwang-Bum

    2013-09-01

    A highly ordered cubic mesoporous silica (KIT-6)/graphene nanocomposite and 2D KIT-6 nanoflakes were synthesized using a novel synthesis methodology. The non-ionic triblock copolymer, P123, played a dual role as a structure-directing agent in the formation of the cubic mesoporous structure and as a cross-linking agent between mesoporous silica and graphene. The prepared (KIT-6)/graphene nanocomposite could act as a template for the preparation of mesoporous material/graphene nanocomposites.A highly ordered cubic mesoporous silica (KIT-6)/graphene nanocomposite and 2D KIT-6 nanoflakes were synthesized using a novel synthesis methodology. The non-ionic triblock copolymer, P123, played a dual role as a structure-directing agent in the formation of the cubic mesoporous structure and as a cross-linking agent between mesoporous silica and graphene. The prepared (KIT-6)/graphene nanocomposite could act as a template for the preparation of mesoporous material/graphene nanocomposites. Electronic supplementary information (ESI) available: S1: TEM images of disordered mesoporous silica/graphene nanocomposite; S2: TEM images of KIT-6/GO nanocomposite; S3: Thermogravimetric analysis of KIT-6/GO and KG-400-700; S4: SEM and TEM images of KIT-6; S5: Low angle XRD, Raman spectra, N2 adsorption isotherms, pore size distribution and photographic images of the prepared samples; S6: TEM image and N2 adsorption isotherms of mesoporous carbon/graphene nanocomposite; S7: XPS C1s spectra of the prepared samples. See DOI: 10.1039/c3nr03108j

  14. The development of chiral nematic mesoporous materials.

    Science.gov (United States)

    Kelly, Joel A; Giese, Michael; Shopsowitz, Kevin E; Hamad, Wadood Y; MacLachlan, Mark J

    2014-04-15

    Cellulose nanocrystals (CNCs) are obtained from the sulfuric acid-catalyzed hydrolysis of bulk cellulose. The nanocrystals have diameters of ~5-15 nm and lengths of ~100-300 nm (depending on the cellulose source and hydrolysis conditions). This lightweight material has mostly been investigated to reinforce composites and polymers because it has remarkable strength that rivals carbon nanotubes. But CNCs have an additional, less explored property: they organize into a chiral nematic (historically referred to as cholesteric) liquid crystal in water. When dried into a thin solid film, the CNCs retain the helicoidal chiral nematic order and assemble into a layered structure where the CNCs have aligned orientation within each layer, and their orientation rotates through the stack with a characteristic pitch (repeating distance). The cholesteric ordering can act as a 1-D photonic structure, selectively reflecting circularly polarized light that has a wavelength nearly matching the pitch. During CNC self-assembly, it is possible to add sol-gel precursors, such as Si(OMe)4, that undergo hydrolysis and condensation as the solvent evaporates, leading to a chiral nematic silica/CNC composite material. Calcination of the material in air destroys the cellulose template, leaving a high surface area mesoporous silica film that has pore diameters of ~3-10 nm. Importantly, the silica is brilliantly iridescent because the pores in its interior replicate the chiral nematic structure. These films may be useful as optical filters, reflectors, and membranes. In this Account, we describe our recent research into mesoporous films with chiral nematic order. Taking advantage of the chiral nematic order and nanoscale of the CNC templates, new functional materials can be prepared. For example, heating the silica/CNC composites under an inert atmosphere followed by removal of the silica leaves highly ordered, mesoporous carbon films that can be used as supercapacitor electrodes. The composition

  15. Mesoporous metal oxide semiconductor-clad waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Miller, L.W.; Tejedor, M.I.; Nelson, B.P.; Anderson, M.A.

    1999-10-07

    Optical waveguides were prepared by depositing a sol gel-derived titania film onto a silica substrate. The titania film is mesoporous, with pore sizes ranging from 3 to 8 nm. Deposition of the titania does not change the critical angle to total internal reflection. Thus, the titania-coated waveguides propagate light in an attenuated total reflection mode, despite the relatively high refractive index (n = 1.8 in air) of the titania film relative to the silica substrate (n = 1.5). The optical and structural properties of these films suggest the possibility of developing efficient photocatalytic reactors or improved optical chemical sensors.

  16. Adsorption-Induced Deformation of Mesoporous Solids

    CERN Document Server

    Gor, Gennady Yu

    2010-01-01

    The Derjaguin - Broekhoff - de Boer theory of capillary condensation is employed to describe deformation of mesoporous solids in the course of adsorption-desorption hysteretic cycles. We suggest a thermodynamic model, which relates the mechanical stress induced by adsorbed phase with the adsorption isotherm. Analytical expressions are derived for the dependence of the solvation pressure on the vapor pressure. The proposed method provides a semi-quantitative description of non-monotonic hysteretic deformation during capillary condensation without invoking any adjustable parameters. The method is showcased drawing on the examples of literature experimental data on adsorption deformation of porous glass and SBA-15 silica.

  17. THE SYNTHESIS OF MODIFIED DIPHENYL OXIDE RESIN

    Institute of Scientific and Technical Information of China (English)

    MAOMingfei; LIUZhifang; 等

    2002-01-01

    Modified diphenyl oxide resin was synthesized by co-polymerization of unsaturated acid and diphenyl oxide derivants.And then modified bismaleimide resin and expoxide linear phenolic resin were added into modified diphenyl oxide resin to co-polymerized and modify once more.The system was applied in composites.Their properties wrer investigated and found that they met the requirements as a heat-resisting adhesive.

  18. Aluminum-rich mesoporous MFI - type zeolite single crystals

    DEFF Research Database (Denmark)

    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...... 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...

  19. Method of removing contaminants from plastic resins

    Science.gov (United States)

    Bohnert,George W.; Hand,Thomas E.; Delaurentiis,Gary M.

    2007-08-07

    A method for removing contaminants from synthetic resin material containers using a first organic solvent system and a second carbon dioxide system. The organic solvent is utilized for removing the contaminants from the synthetic resin material and the carbon dioxide is used to separate any residual organic solvent from the synthetic resin material.

  20. Method for removing contaminants from plastic resin

    Science.gov (United States)

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2008-12-30

    A method for removing contaminants from synthetic resin material containers using a first organic solvent system and a second carbon dioxide system. The organic solvent is utilized for removing the contaminants from the synthetic resin material and the carbon dioxide is used to separate any residual organic solvent from the synthetic resin material.

  1. 21 CFR 177.1595 - Polyetherimide resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyetherimide resin. 177.1595 Section 177.1595... Components of Single and Repeated Use Food Contact Surfaces § 177.1595 Polyetherimide resin. The polyetherimide resin identified in this section may be safely used as an article or component of an...

  2. 21 CFR 177.1556 - Polyaryletherketone resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyaryletherketone resins. 177.1556 Section 177... Components of Single and Repeated Use Food Contact Surfaces § 177.1556 Polyaryletherketone resins. The poly...) resins (CAS Reg. No. 55088-54-5 and CAS Reg. No. 60015-05-6 and commonly referred to...

  3. 21 CFR 177.1555 - Polyarylate resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyarylate resins. 177.1555 Section 177.1555 Food... of Single and Repeated Use Food Contact Surfaces § 177.1555 Polyarylate resins. Polyarylate resins... contact with food in accordance with the following prescribed conditions: (a) Identity. Polyarylate...

  4. 21 CFR 177.1560 - Polyarylsulfone resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyarylsulfone resins. 177.1560 Section 177.1560... Components of Single and Repeated Use Food Contact Surfaces § 177.1560 Polyarylsulfone resins. Polyarylsulfone resins (CAS Reg. No. 79293-56-4) may be safely used as articles or components of articles...

  5. 40 CFR 721.9495 - Acrylosilane resins.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acrylosilane resins. 721.9495 Section... Substances § 721.9495 Acrylosilane resins. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified as acrylosilane resins (PMNs P-95-1024/1040) are...

  6. 21 CFR 872.3140 - Resin applicator.

    Science.gov (United States)

    2010-04-01

    ... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3140 Resin applicator. (a) Identification. A resin applicator is a brushlike device intended for use in spreading dental resin on a tooth during application of tooth shade material. (b) Classification. Class I (general controls). The device is exempt from...

  7. 21 CFR 172.280 - Terpene resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Terpene resin. 172.280 Section 172.280 Food and..., Films and Related Substances § 172.280 Terpene resin. The food additive terpene resin may be safely used... polymer obtained by polymerizing terpene hydrocarbons derived from wood. It has a softening point of...

  8. 21 CFR 177.1680 - Polyurethane resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyurethane resins. 177.1680 Section 177.1680 Food... of Single and Repeated Use Food Contact Surfaces § 177.1680 Polyurethane resins. The polyurethane...) For the purpose of this section, polyurethane resins are those produced when one or more of...

  9. Ordered hierarchical mesoporous/microporous carbon derived from mesoporous titanium-carbide/carbon composites and its electrochemical performance in supercapacitor

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hai-Jing; Wang, Jie; Wang, Cong-Xiao; Xia, Yong-Yao [Department of Chemistry and Shanghai Key Laboratory of Molecular, Catalysis and Innovative Materials, Institute of New Energy, Fudan University, Shanghai (China)

    2011-11-15

    Novel ordered hierarchical mesoporous/microporous carbon (OHMMC) derived from mesoporous titanium-carbide/carbon composites was prepared for the first time by synthesizing ordered mesoporous nanocrystalline titanium-carbide/carbon composites, followed by chlorination of titanium carbides. The mesostructure and microstructure can be conveniently tuned by controlling the TiC contents of mesoporous TiC/C composite precursor, and chlorination temperature. By optimal condition, the OHMMC has a high surface area (1917 m{sup 2}g{sup -1}), large pore volumes (1.24 cm{sup 3}g{sup -1}), narrow mesopore-size distributions (centered at about 3 nm), and micropore size of 0.69 and 1.25 nm, and shows a great potential as electrode for supercapacitor applications: it exhibits a high capacitance of 146 Fg{sup -1} in noaqueous electrolyte and excellent rate capability. The ordered mesoporous channel pores are favorable for retention and immersion of the electrolyte, providing a more favorable path for electrolyte penetration and transportation to achieve promising rate capability performance. Meanwhile, the micropores drilled on the mesopore-walls can increase the specific surface area to provide more sites for charge storage. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Phosphoryl functionalized mesoporous silica for uranium adsorption

    Science.gov (United States)

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

    2017-04-01

    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), N2 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 (ΔG0, ΔH0 and ΔS0) confirmed that the adsorption process was endothermic and spontaneous.

  11. Biodegradable mesoporous delivery system for biomineralization precursors

    Science.gov (United States)

    Yang, Hong-ye; Niu, Li-na; Sun, Jin-long; Huang, Xue-qing; Pei, Dan-dan; Huang, Cui; Tay, Franklin R

    2017-01-01

    Scaffold supplements such as nanoparticles, components of the extracellular matrix, or growth factors have been incorporated in conventional scaffold materials to produce smart scaffolds for tissue engineering of damaged hard tissues. Due to increasing concerns on the clinical side effects of using large doses of recombinant bone-morphogenetic protein-2 in bone surgery, it is desirable to develop an alternative nanoscale scaffold supplement that is not only osteoinductive, but is also multifunctional in that it can perform other significant bone regenerative roles apart from stimulation of osteogenic differentiation. Because both amorphous calcium phosphate (ACP) and silica are osteoinductive, a biodegradable, nonfunctionalized, expanded-pore mesoporous silica nanoparticle carrier was developed for loading, storage, and sustained release of a novel, biosilicification-inspired, polyamine-stabilized liquid precursor phase of ACP for collagen biomineralization and for release of orthosilicic acid, both of which are conducive to bone growth. Positively charged poly(allylamine)-stabilized ACP (PAH-ACP) could be effectively loaded and released from nonfunctionalized expanded-pore mesoporous silica nanoparticles (pMSN). The PAH-ACP released from loaded pMSN still retained its ability to infiltrate and mineralize collagen fibrils. Complete degradation of pMSN occurred following unloading of their PAH-ACP cargo. Because PAH-ACP loaded pMSN possesses relatively low cytotoxicity to human bone marrow-derived mesenchymal stem cells, these nanoparticles may be blended with any osteoconductive scaffold with macro- and microporosities as a versatile scaffold supplement to enhance bone regeneration. PMID:28182119

  12. Continuous microwave flow synthesis of mesoporous hydroxyapatite.

    Science.gov (United States)

    Akram, Muhammad; Alshemary, Ammar Z; Goh, Yi-Fan; Wan Ibrahim, Wan Aini; Lintang, Hendrik O; Hussain, Rafaqat

    2015-11-01

    We have successfully used continuous microwave flow synthesis (CMFS) technique for the template free synthesis of mesoporous hydroxyapatite. The continuous microwave flow reactor consisted of a modified 2.45GHz household microwave, peristaltic pumps and a Teflon coil. This cost effective and efficient system was exploited to produce semi-crystalline phase pure nano-sized hydroxyapatite. Effect of microwave power, retention time and the concentration of reactants on the phase purity, degree of crystallinity and surface area of the final product was studied in detail. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to study the phase purity and composition of the product, while transmission electron microscopy (TEM) was used to study the effect of process parameters on the morphology of hydroxyapatite. The TEM analysis confirmed the formation of spherical particles at low microwave power; however the morphology of the particles changed to mesoporous needle and rod-like structure upon exposing the reaction mixture to higher microwave power and longer retention time inside the microwave. The in-vitro ion dissolution behavior of the as synthesized hydroxyapatite was studied by determining the amount of Ca(2+) ion released in SBF solution.

  13. Colloidal suspensions of functionalized mesoporous silica nanoparticles.

    Science.gov (United States)

    Kobler, Johannes; Möller, Karin; Bein, Thomas

    2008-04-01

    The synthesis and characterization of colloidal mesoporous silica (CMS) functionalized with vinyl-, benzyl-, phenyl-, cyano-, mercapto-, aminopropyl- or dihydroimidazole moieties is reported. Uniform mesoporous particles ranging in size from 40 to 150 nm are generated in a co-condensation process of tetraethylorthosilicate (TEOS) and organotriethoxysilanes (RTES) in alkaline aqueous media containing triethanolamine (TEA) in combination with cetyltrimethylammonium chloride (CTACl) serving as a structure-directing agent. The materials are obtained as colloidal suspensions featuring long-term stability after template removal by ion exchange with an ethanolic solution of ammonium nitrate or HCl. The spherical particles exhibit a wormlike pore system with defined pore sizes and high surface areas. Samples are analyzed by a number of techniques including TEM, SEM, DLS, TGA, Raman, and cross-polarized (29)Si-MAS NMR spectroscopy, as well as nitrogen sorption measurements. We demonstrate that co-condensation and grafting methods result in similar changes in the nitrogen adsorption behavior, indicating a successful internal lining of the pores with functional groups through both procedures.

  14. Smart Mesoporous Nanomaterials for Antitumor Therapy

    Directory of Open Access Journals (Sweden)

    Marina Martínez-Carmona

    2015-11-01

    Full Text Available The use of nanomaterials for the treatment of solid tumours is receiving increasing attention by the scientific community. Among them, mesoporous silica nanoparticles (MSNs exhibit unique features that make them suitable nanocarriers to host, transport and protect drug molecules until the target is reached. It is possible to incorporate different targeting ligands to the outermost surface of MSNs to selectively drive the drugs to the tumour tissues. To prevent the premature release of the cargo entrapped in the mesopores, it is feasible to cap the pore entrances using stimuli-responsive nanogates. Therefore, upon exposure to internal (pH, enzymes, glutathione, etc. or external (temperature, light, magnetic field, etc. stimuli, the pore opening takes place and the release of the entrapped cargo occurs. These smart MSNs are capable of selectively reaching and accumulating at the target tissue and releasing the entrapped drug in a specific and controlled fashion, constituting a promising alternative to conventional chemotherapy, which is typically associated with undesired side effects. In this review, we overview the recent advances reported by the scientific community in developing MSNs for antitumor therapy. We highlight the possibility to design multifunctional nanosystems using different therapeutic approaches aimed at increasing the efficacy of the antitumor treatment.

  15. Morphology control of ordered mesoporous carbons for high capacity lithium sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Joerg David

    2011-06-07

    The focus of this thesis concerns the morphology control of ordered mesoporous carbon (OMC) materials. Ordered mesoporous carbons with diverse morphologies, that are thin films, fibers - embedded in anodic alumina membranes and free-standing - or spherical nanoparticles, have been successfully prepared by soft-templating procedures. The mechanisms of structure formation and processing were investigated with in-situ SAXS measurements and their application in high capacity lithium-sulfur batteries was successfully tested in cooperation with Guang He and Linda Nazar from the University of Waterloo in Canada. The Li-S batteries receive increasing attention due to their high theoretical energy density which is 3 to 5 times higher than from lithium-ion batteries. For this type of battery the specific pore volume is crucial for the content of the active component (sulfur) in the cathode and therefore correlates with the capacity and gravimetric energy density of the battery. At first, mesoporous thin films with 2D-hexagonal structure were obtained through organic-organic self-assembly of a preformed oligomeric resol precursor and the triblock copolymer template Pluronic P123. The formation of a condensed-wall material through thermopolymerization of the precursor oligomers resulted in mesostructured phenolic resin films. Subsequent decomposition of the surfactant and partial carbonization were achieved through thermal treatment in inert atmosphere. The films were crack-free with tunable homogenous thicknesses, and showed either 2D-hexagonal or lamellar mesostructure. An additional, yet unknown 3D-mesostructure was also found. In the second part, cubic and circular hexagonal mesoporous carbon phases in the confined environment of tubular anodic alumina membrane (AAM) pores were obtained by self-assembly of the mentioned resol precursor and the triblock copolymer templates Pluronic F127 or P123, respectively. Casting and solvent-evaporation were also followed by

  16. Application of mesoporous carbon and modified mesoporous carbon for treatment of DMF sewage

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. [Epoxy resin systems and contact dermatitis].

    Science.gov (United States)

    Pietranek, Jolanta Eliza

    2007-01-01

    Contact dermatitis is the major chronic skin disease that represents a global health problem. Its prevalence has been significant increasing in the latest decades. Contact dermatitis substantially alters the social life of patients and affects their work productivity. Epoxy resin systems are a frequent cause of occupational allergic contact dermatitis. Epoxy resins have an extremely wide range of commercial applications. Epoxy resin systems include combinations of epoxy monomers, hardeners, reactive diluents, and/or a vast array of other additives. In occupational settings, sensitization occurs not only to resins, but also to hardeners and reactive diluents. In this article adverse effects of epoxy resin systems are discussed.

  18. Stochastic resin transfer molding process

    CERN Document Server

    Park, M

    2016-01-01

    We consider one-dimensional and two-dimensional models of stochastic resin transfer molding process, which are formulated as random moving boundary problems. We study their properties, analytically in the one-dimensional case and numerically in the two-dimensional case. We show how variability of time to fill depends on correlation lengths and smoothness of a random permeability field.

  19. Occupational exposure to epoxy resins

    NARCIS (Netherlands)

    Terwoert, J.; Kersting, K.

    2014-01-01

    Products based on epoxy resins as a binder have become popular in various settings, among which the construction industry and in windmill blade production, as a result of their excellent technical properties. However, due to the same properties epoxy products are a notorious cause of allergic skin d

  20. Synthesis of Nanometer-sized Mesoporous Oxide Spheres

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A few hundreds nanometer-sized mesoporous silica and alumina spheres were synthesized in organic solvents. The impacts of ammonia, N,N-dimethylformamide (DMF) and stirring speed were also investigated.

  1. Mesoporous zeolite single crystals for catalytic hydrocarbon conversion

    DEFF Research Database (Denmark)

    Schmidt, I.; Christensen, C.H.; Hasselriis, Peter

    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....

  2. Underpotential deposition and anodic stripping voltammetry at mesoporous microelectrodes.

    Science.gov (United States)

    Sanchez, Pablo Lozano; Elliott, Joanne M

    2005-05-01

    Using the technique of liquid crystal templating a series of high surface area mesoporous platinum microelectrodes was fabricated. The underpotential deposition of metal ions at such electrodes was found to be similar to that at conventional platinum electrodes. The phenomena of underpotential deposition, in combination with the intrinsic properties of mesoporous microelectrodes (i.e. a high surface area and efficient mass transport) was exploited for the purpose of anodic stripping voltammetry. In particular the underpotential deposition of Ag(+), Pb(2+) and Cu(2+) ions was investigated and it was found that mesoporous microelectrodes were able to quantify the concentration of ions in solution down to the ppb range. The overall behaviour of the mesoporous electrodes was found to be superior to that of conventional microelectrodes and the effects of interference by surfactants were minimal.

  3. Mesoporous Silicas with Tunable Morphology for the Immobilization of Laccase

    Directory of Open Access Journals (Sweden)

    Victoria Gascón

    2014-05-01

    Full Text Available Siliceous ordered mesoporous materials (OMM are gaining interest as supports for enzyme immobilization due to their uniform pore size, large surface area, tunable pore network and the introduction of organic components to mesoporous structure. We used SBA-15 type silica materials, which exhibit a regular 2D hexagonal packing of cylindrical mesopores of uniform size, for non-covalent immobilization of laccase. Synthesis conditions were adjusted in order to obtain supports with different particle shape, where those with shorter channels had higher loading capacity. Despite the similar isoelectric points of silica and laccase and the close match between the size of laccase and the pore dimensions of these SBA-15 materials, immobilization was achieved with very low leaching. Surface modification of macro-/mesoporous amorphous silica by grafting of amine moieties was proved to significantly increase the isoelectric point of this support and improve the immobilization yield.

  4. Mesoporous silica magnetite nanocomposite synthesized by using a neutral surfactant

    Science.gov (United States)

    Souza, K. C.; Salazar-Alvarez, G.; Ardisson, J. D.; Macedo, W. A. A.; Sousa, E. M. B.

    2008-05-01

    Magnetite nanoparticles coated by mesoporous silica were synthesized by an alternative chemical route using a neutral surfactant and without the application of any functionalization method. The magnetite (Fe3O4) nanoparticles were prepared by precipitation from aqueous media, and then coated with mesoporous silica by using nonionic block copolymer surfactants as the structure-directing agents. The mesoporous SiO2-coated Fe3O4 samples were characterized by x-ray diffraction, Fourier-transform infrared spectroscopy, N2 adsorption-desorption isotherms, transmission electron microscopy, 57Fe Mössbauer spectroscopy, and vibrating sample magnetometry. Our results revealed that the magnetite nanoparticles are completely coated by well-ordered mesoporous silica with free pores and stable (~8 nm thick) pore walls, and that the structural and magnetic properties of the Fe3O4 nanoparticles are preserved in the applied synthesis route.

  5. BITEMPLATE SYNTHESIS OF MESOPOROUS SILICAS WITH THIOUREA GROUPS

    Directory of Open Access Journals (Sweden)

    O. I. Gona

    2009-06-01

    Full Text Available Mesoporous silicas with the thiourea functional group ≡Si(CH23NHC(SNHC2H5 have been synthesized by monotemplate and bitemplate route (bitemplate is cetylpyridinium chloride as micelle-forming surfactant and monoethanolamide of saturated n-aliphatic acid as non-micelle-forming surfactant. The infl uence of a number of factors on mesoporous silicas structure has been studied: alkoxysilanes and surfactants concentration, and as well as the nature of medium in hydrothermal treatment of mesophases. The optimum conditions under which functionalized mesoporous silicas have possessing highly ordered hexagonal structure have been found. The surface area of mesoporous silicas synthesized using optimum bitemplate solubilization composition reaches 1055-1350 m2/g and sorption volume and pore diameter are 0.75-0.95 cm3/g and 2.5-2.9 nm respectively.

  6. Synthesis of mesoporous nano-hydroxyapatite by using zwitterions surfactant

    Science.gov (United States)

    Mesoporous nano-hydroxyapatite (mn-HAP) was successfully synthesized via a novel micelle-templating method using lauryl dimethylaminoacetic acid as zwitterionic surfactant. The systematic use of such a surfactant in combination with microwave energy inputenables the precise contr...

  7. Phosphorus recovery by mesoporous structure material from wastewater.

    Science.gov (United States)

    Lee, S H; Lee, B C; Lee, K W; Lee, S H; Choi, Y S; Park, K Y; Iwamoto, M

    2007-01-01

    This study was designed to investigate the fundamental aspects of a possible removal of phosphorous from wastewater by using the mesoporous structure materials for wastewater reuse. The zirconium sulphate with mesoporous structure as a new type of ion exchangers was synthesised by hydrothermal reaction. From the results of X-ray diffraction and transmission electron microscope, it was discovered that the synthesised material had hexagonal mesoporous structure with a pore size of approximately 40-50A. Experimental results showed that the zirconium sulphate with mesoporous structure had very high sorption capacity for the phosphorus. The novel ion exchange occurred between PO4(3-) and SO4(2-), OH-. The amount of phosphate ions exchanged into the solid was as great as 3.4 mmol/g-ZS. Furthermore, it is possible to obtain a higher removal efficiency than other ion exchange media and adsorbents.

  8. [Dimensional accuracy of microwave-cured denture base resin].

    Science.gov (United States)

    Uchida, K; Okamoto, F; Ogata, K; Sato, T

    1989-02-01

    Recently, microwave-cured denture base resin was developed, and the resin solved the problem of internal porosity which had been generated by curing the conventional denture base resins with microwave irradiation. In this study, the dimensional accuracy of microwave-cured denture base resin was compared with that of other denture base resins, such as pour-type resin, heat-cured resin and heat-shock resin. From the experiment, the following results were obtained. 1. Dimensional accuracy of microwave-cured denture base resin was better than that of heat-cured resin and heat-shock resin, and was similar to that of pour-type resin. 2. Dimensional accuracy of microwave-cured denture base resin by slow cooling method and rapid cooling method was almost the same. Those findings suggest that microwave-cured denture base resin is valuable in clinic.

  9. Photoacoustic analysis of dental resin polymerization

    Science.gov (United States)

    Coloiano, E. C. R.; Rocha, R.; Martin, A. A.; da Silva, M. D.; Acosta-Avalos, D.; Barja, P. R.

    2005-06-01

    In this work, we use the photoacoustic technique to monitor the curing process of diverse dental materials, as the resins chemically activated (RCA). The results obtained reveal that the composition of a determined RCA significantly alters its activation kinetics. Photoacoustic data also show that temperature is a significant parameter in the activation kinetics of resins. The photoacoustic technique was also applied to evaluate the polymerization kinetics of photoactivated resins. Such resins are photoactivated by incidence of continuous light from a photodiode. This leads to the polymerization of the resin, modifying its thermal properties and, consequently, the level of the photoacoustic signal. Measurements show that the polymerization of the resin changes the photoacoustic signal amplitude, indicating that photoacoustic measurements can be utilized to monitor the polymerization kinetic and the degree of polymerization of photoactivated dental resins.

  10. Preparation of mesoporous aluminophosphate usingpoly(amido amine) as template

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiaofeng; LIN Shen; CHEN Xinqing; CHEN Jiebo; YANG Liuyi; LUO Minghong

    2007-01-01

    Mesoporous aluminophosphate was prepared by using G4.0 poly(amido amine)dendrimer as a template and characterized by Fourier transform infrared spectrometer(FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and N2 adsorption/desorption methods.Results show that the title compound exhibits a typical mesoporous structure with the average pore size from 5 to 8 nm. The formation mechanism of the nanoporous structure using dendrimer as a template was also discussed.

  11. Solar hydrogen and solar electricity using mesoporous materials

    Science.gov (United States)

    Mahoney, Luther

    The development of cost-effective materials for effective utilization of solar energy is a major challenge for solving the energy problems that face the world. This thesis work relates to the development of mesoporous materials for solar energy applications in the areas of photocatalytic water splitting and the generation of electricity. Mesoporous materials were employed throughout the studies because of their favorable physico-chemical properties such as high surface areas and large porosities. The first project was related to the use of a cubic periodic mesoporous material, MCM-48. The studies showed that chromium loading directly affected the phase of mesoporous silica formed. Furthermore, within the cubic MCM-48 structure, the loading of polychromate species determined the concentration of solar hydrogen produced. In an effort to determine the potential of mesoporous materials, titanium dioxide was prepared using the Evaporation-Induced Self-Assembly (EISA) synthetic method. The aging period directly determined the amount of various phases of titanium dioxide. This method was extended for the preparation of cobalt doped titanium dioxide for solar simulated hydrogen evolution. In another study, metal doped systems were synthesized using the EISA procedure and rhodamine B (RhB) dye sensitized and metal doped titania mesoporous materials were evaluated for visible light hydrogen evolution. The final study employed various mesoporous titanium dioxide materials for N719 dye sensitized solar cell (DSSC) materials for photovoltaic applications. The materials were extensively characterized using powder X-ray diffraction (XRD), nitrogen physisorption, diffuse reflectance spectroscopy (DRS), UV-Vis spectroscopy, Fourier-Transform-Infrared Spectroscopy (FT-IR), Raman spectroscopy, chemisorption, photoluminescence (PL), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). In addition, photoelectrochemical measurements were completed using

  12. Biodegradable mesoporous delivery system for biomineralization precursors

    Directory of Open Access Journals (Sweden)

    Yang HY

    2017-01-01

    Full Text Available Hong-ye Yang,1 Li-na Niu,2 Jin-long Sun,2 Xue-qing Huang,3 Dan-dan Pei,4 Cui Huang,1 Franklin R Tay5 1The State Key Laboratory Breeding Base of Basic Science of Stomatology, Key Laboratory for Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, Hubei, People’s Republic of China; 2State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Key Laboratory of Oral Diseases, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China; 3Department of Prosthodontics, Guanghua School and Hospital of Stomatology, Guangdong Key Laboratory of Stomatology, Yat-sen University, Guangzhou, Guangdong, People’s Republic of China; 4Department of Prosthodontics, College of Stomatology, Xi’an Jiaotong University, Xi’an, Shaanxi, People’s Republic of China; 5Department of Endodontics, College of Dental Medicine, Augusta University, Augusta, GA, USA Abstract: Scaffold supplements such as nanoparticles, components of the extracellular matrix, or growth factors have been incorporated in conventional scaffold materials to produce smart scaffolds for tissue engineering of damaged hard tissues. Due to increasing concerns on the clinical side effects of using large doses of recombinant bone-morphogenetic protein-2 in bone surgery, it is desirable to develop an alternative nanoscale scaffold supplement that is not only osteoinductive, but is also multifunctional in that it can perform other significant bone regenerative roles apart from stimulation of osteogenic differentiation. Because both amorphous calcium phosphate (ACP and silica are osteoinductive, a biodegradable, nonfunctionalized, expanded-pore mesoporous silica nanoparticle carrier was developed for loading, storage, and sustained release of a novel, biosilicification-inspired, polyamine-stabilized liquid precursor phase of ACP

  13. Ultrasound-driven design of new mesoporous metal catalysts

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Adsorption of octadecyltrichlorosilane on mesoporous SBA-15

    Energy Technology Data Exchange (ETDEWEB)

    Mirji, S.A. [Physical Chemistry Division, National Chemical Laboratory, Pune 411008 (India)]. E-mail: mirji@dalton.ncl.res.in; Halligudi, S.B. [Inorganic and Catalysis Division, National Chemical Laboratory, Pune 411008 (India); Sawant, Dhanashri P. [Inorganic and Catalysis Division, National Chemical Laboratory, Pune 411008 (India); Jacob, Nalini E. [Inorganic and Catalysis Division, National Chemical Laboratory, Pune 411008 (India); Patil, K.R. [Center for Material Characterization, National Chemical Laboratory, Pune 411008 (India); Gaikwad, A.B. [Center for Material Characterization, National Chemical Laboratory, Pune 411008 (India); Pradhan, S.D. [Center for Material Characterization, National Chemical Laboratory, Pune 411008 (India)

    2006-04-15

    Adsorption of octadecyltrichlorosilane (OTS) on mesoporous SBA-15 has been studied by using Brunauer-Emmett-Teller (BET) surface area analysis, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and thermo-gravimetric analysis (TGA) techniques. BET surface area analysis shows decrease of surface area from 930 to 416 m{sup 2}/g after OTS adsorption. SEM pictures show close attachment of SBA-15 particles. EDAX measurements show increase of carbon weight percentage and decrease of oxygen and silicon weight percentage. XPS results closely support EDAX analysis. FTIR spectra shows presence of methyl (-CH{sub 3}) and methylene (-CH{sub 2}) bands and oriented OTS monolayer on SBA-15. Thermo-gravimetric analysis shows that the OTS adsorbed on SBA-15 are stable up to a temperature of 230 deg. C and that the OTS monolayers decompose between 230 and 400 deg. C.

  15. Stabilization of mesoporous nanocrystalline zirconia with Laponite

    Institute of Scientific and Technical Information of China (English)

    LIU Xinmei; YAN Zifeng; LU Gaoqing

    2005-01-01

    The mesoporous nanocrystalline zircoina was synthesized via solid state reaction--structure directing method in the presence of Laponite. The introduction of Laponite renders the higher thermal stability and lamellar track to the zirconia. Laponite acts as inhibitor for crystal growth and also hard template for the mesostructure. The role of Laponite is attributed to the interaction between the zirconia precursors and the nano-platelets of Laponite via the bridge of hydrophilic segments of surfactant. It results in the formation of Zr-O-Mg-O-Si frameworks in the direction of Laponite layer with the condensation of frameworks during the calcination process, which contributes the higher stability and lamellar structure to the nano-sized zirconia samples.

  16. Enantioselective recognition at mesoporous chiral metal surfaces

    Science.gov (United States)

    Wattanakit, Chularat; Côme, Yémima Bon Saint; Lapeyre, Veronique; Bopp, Philippe A.; Heim, Matthias; Yadnum, Sudarat; Nokbin, Somkiat; Warakulwit, Chompunuch; Limtrakul, Jumras; Kuhn, Alexander

    2014-02-01

    Chirality is widespread in natural systems, and artificial reproduction of chiral recognition is a major scientific challenge, especially owing to various potential applications ranging from catalysis to sensing and separation science. In this context, molecular imprinting is a well-known approach for generating materials with enantioselective properties, and it has been successfully employed using polymers. However, it is particularly difficult to synthesize chiral metal matrices by this method. Here we report the fabrication of a chirally imprinted mesoporous metal, obtained by the electrochemical reduction of platinum salts in the presence of a liquid crystal phase and chiral template molecules. The porous platinum retains a chiral character after removal of the template molecules. A matrix obtained in this way exhibits a large active surface area due to its mesoporosity, and also shows a significant discrimination between two enantiomers, when they are probed using such materials as electrodes.

  17. Synthesis of ordered mesoporous U{sub 3}O{sub 8} by a nanocasting route

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Ran; Wang, Lin; Gu, Zhan-Jun; Yuan, Li-Yong; Xiao, Cheng-Liang; Zhao, Yu-Liang; Shi, Wei-Qun [Institute of High Energy Physics, Beijing (China). Key Laboratory of Nuclear Radiation and Nuclear Energy Technology; Chai, Zhi-Fang [Institute of High Energy Physics, Beijing (China). Key Laboratory of Nuclear Radiation and Nuclear Energy Technology; Soochow Univ., Suzhou (China). School of Radiological and Interdisciplinary Sciences

    2014-11-01

    Ordered mesoporous U{sub 3}O{sub 8} has been synthesized by a nanocasting route using mesoporous silica (KIT-6 and SBA-15) as templates and characterized by using XRD, SEM and nitrogen adsorption/desorption techniques.

  18. PENGARUH STRUKTUR PORI TERHADAP KAPASITANSI ELEKTRODA SUPERKAPASITOR YANG DIBUAT DARI KARBON NANOPORI

    Directory of Open Access Journals (Sweden)

    Teguh Ariyanto

    2012-05-01

    Full Text Available THE EFFECT OF PORE STRUCTURE ON THE ELECTRODE CAPACITANCE OF SUPERCAPACITOR PREPARED BY NANOPOROUS CARBON. Nanoporous carbons, due to high specific surface area, high pore accessibility, and relatively low cost, have been used as material electrode supercapacitors. In this work, the influence of pore structure of nanoporous carbons on the specific capacitance of supercapacitors was examined. Nanoporous carbons with several types of pore structure were prepared by carbonization of phenolic resin produced by polymeric condensation of phenolic compound with formaldehyde. Furthermore, ethylene glycol, as a filler, was added in the phenolic resin polymerization to increase the mesoporosity of nanoporous carbon. The nanoporous carbons produced were characterized for their surface morphology, specific internal surface area (BET method, and pore structure. Samples were used as electrode material in supercapacitor and specific capacitances were characterized by galvanostatic test using 30% KOH aqueous solution as electrolyte. The capacitance test of supercapacitors exhibited that increasing mesoporosity increase specific capacitance value of supercapacitors. The highest specific capacitance of 336 F/g was obtained by using mesoporous carbon produced by carbonization of resorcinol phenol formaldehyde ethylene glycol (C-RPFEG2 as electrode material of supercapacitors.  Karbon nanopori dikarenakan memiliki luas permukaan internal yang tinggi, aksesibilitas pori yang baik, dan relatif murah telah digunakan sebagai material elektroda superkapasitor. Pada penelitian ini, pengaruh struktur pori dari karbon nanopori terhadap kapasitansi spesifik superkapasitor telah dipelajari. Karbon berpori dengan berbagai struktur pori dibuat dengan cara karbonisasi phenolic resin yang dibuat dengan cara polimerisaasi kondensasi senyawa phenolic dengan formaldehyde. Selain itu, etilen glikol sebagai filler ditambahkan pada saat polimerisasi phenolic resin untuk meningkatkan

  19. Eleventh All-Union Conference on High-Molecular-Weight Compounds

    Science.gov (United States)

    1960-07-18

    sulfonation , phosphorylization, and mercaptylization [merkaptilirovaniye]. The lecturer includes in this group of transformations also the reactions of...with alkyd and alkyd- melamine resins; the communication of V. V. Zhebrovskiy, M. I. Karyakina, F. I. Rubenshteyn and S. V. Yakubovich (State Research...based on epoxy resins, combined with phenol- formaldehyde resins and mixed methacrylic esters. K. I. Zabyrina, M. B. Fromberg, Ye. P. Gruzdova, and V

  20. Mesoporous metal oxide microsphere electrode compositions and their methods of making

    Energy Technology Data Exchange (ETDEWEB)

    Parans Paranthaman, Mariappan; Bi, Zhonghe; Bridges, Craig A.; Brown, Gilbert M.

    2017-04-11

    Compositions and methods of making are provided for treated mesoporous metal oxide microspheres electrodes. The compositions include microspheres with an average diameter between about 200 nanometers and about 10 micrometers and mesopores on the surface and interior of the microspheres. The methods of making include forming a mesoporous metal oxide microsphere composition and treating the mesoporous metal oxide microspheres by at least annealing in a reducing atmosphere, doping with an aliovalent element, and coating with a coating composition.

  1. Resin Diterpenes from Austrocedrus chilensis

    Directory of Open Access Journals (Sweden)

    Verónica Rachel Olate

    2011-12-01

    Full Text Available Seventeen diterpenes belonging to the labdane, abietane and isopimarane skeleton classes were isolated from the resin of the Chilean gymnosperm Austrocedrus chilensis and identified by spectroscopic and spectrometric methods. The diterpene 12-oxo-labda-8(17,13E-dien-19 oic acid is reported for the first time as a natural product and 14 diterpenes are reported for the first time for the species.

  2. Scintillating 99Tc Selective Ion Exchange Resins

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell Greenhalgh; Richard D. Tillotson

    2012-07-01

    Scintillating technetium (99Tc) selective ion exchange resins have been developed and evaluated for equilibrium capacities and detection efficiencies. These resins can be utilized for the in-situ concentration and detection of low levels of pertechnetate anions (99TcO4-) in natural waters. Three different polystyrene type resin support materials were impregnated with varying amounts of tricaprylmethylammonium chloride (Aliquat 336) extractant, several different scintillating fluors and wavelength shifters. The prepared resins were contacted batch-wise to equilibrium over a wide range of 99TcO4- concentrations in natural water. The measured capacities were used to develop Langmuir adsorption isotherms for each resin. 99Tc detection efficiencies were determined and up to 71.4 ± 2.6% was achieved with some resins. The results demonstrate that a low level detection limit for 99TcO4- in natural waters can be realized.

  3. Novel mesoporous composites based on natural rubber and hexagonal mesoporous silica: Synthesis and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Nuntang, Sakdinun; Poompradub, Sirilux [Fuels Research Center, Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Patumwan, Bangkok 10330 (Thailand); Butnark, Suchada [PTT Research and Technology Institute, PTT Public Company Limited, Wangnoi, Ayutthaya 13170 (Thailand); Yokoi, Toshiyuki; Tatsumi, Takashi [Division of Catalytic Chemistry, Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan); Ngamcharussrivichai, Chawalit, E-mail: Chawalit.Ng@Chula.ac.th [Fuels Research Center, Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Patumwan, Bangkok 10330 (Thailand); Center of Excellence on Petrochemical and Materials Technology (PETROMAT), Chulalongkorn University, Patumwan, Bangkok 10330 (Thailand)

    2014-02-14

    The present study is the first report on the synthesis and characterization of mesoporous composites based on natural rubber (NR) and hexagonal mesoporous silica (HMS). A series of NR/HMS composites were prepared in tetrahydrofuran via an in situ sol–gel process using tetraethylorthosilicate as the silica precursor. The physicochemical properties of the composites were characterized by various techniques. The effects of the gel composition on the structural and textural properties of the NR/HMS composites were investigated. The Fourier-transform infrared spectroscopy (FTIR) and {sup 29}Si magic angle spinning nuclear magnetic resonance ({sup 29}Si MAS NMR) results revealed that the surface silanol groups of NR/HMS composites were covered with NR molecules. The powder X-ray diffraction (XRD) and transmission electron microscopy (TEM) data indicated an expansion of the hexagonal unit cell and channel wall thickness due to the incorporation of NR molecules into the mesoporous structure. NR/HMS composites also possessed nanosized particles (∼79.4 nm) as confirmed by scanning electron microscopy (SEM) and particle size distribution analysis. From N{sub 2} adsorption–desorption measurement, the NR/HMS composites possessed a high BET surface area, large pore volume and narrow pore size distribution. Further, they were enhanced hydrophobicity confirmed by H{sub 2}O adsorption–desorption measurement. In addition, the mechanistic pathway of the NR/HMS composite formation was proposed. - Highlights: • NR molecules were incorporated into hexagonal meso-structure of HMS. • NR/HMS composites exhibited an expanded unit cell and channel wall thickness. • Nanosized NR/HMS composites with a lower particle size range were obtained. • NR/HMS had high surface area, large pore volume and narrow pore size distribution. • NR/HMS composites displayed an enhanced hydrophobicity.

  4. Environmentally Compliant Vinyl Ester Resin (VER) Composite Matrix Resin Derived from Renewable Resources

    Science.gov (United States)

    2011-11-01

    UV Ultraviolet VARTM vacuum-assisted resin transfer molding VE vinyl ester VER QNA vinyl ester resin QinetiQ North America -v...tempera- ture using vacuum-assisted resin transfer molding ( VARTM ) into massive carbon-fiber- reinforced composite structures such as ship hulls and...weapons system components using a low-cost vacuum-assisted resin transfer molded ( VARTM ) process. Steps to commercialize the pro- cess would

  5. Gold Loading on Ion Exchange Resins in Non-Ammoniacal Resin-Solution Systems

    OpenAIRE

    Abrar Muslim

    2010-01-01

    The loading of gold using strong base anion exchange resin in non-ammoniac resin-solution (NARS) systems has been studied. The loading of gold onto ion exchange resins is affected by polythionate concentration, and trithionate can be used as the baseline in the system. The results also show that resin capacity on gold loading increases due to the increase in the equilibrium thiosulfate concentration in the NARS system. Gold loading performances show the need of optimization the equilibrium co...

  6. Epoxy Resins Modified with Vegetable Oils

    Institute of Scientific and Technical Information of China (English)

    P.Czub

    2007-01-01

    1 Results The application of modified natural oils, nontoxic, biodegradable and renewable materials, for the modification and the synthesis of epoxy resins were presented. Firstly, the application of epoxidized vegetable oils (soybean, rapeseed, linseed and sunflower):as reactive diluents for epoxy resins was proposed and studied[1-2]. Viscosity reducing ability of epoxidized oils was tested in the compositions with Bisphenol A based low-molecular-weight epoxy resins. The rheological behaviour of the mi...

  7. Release and toxicity of dental resin composite

    OpenAIRE

    Saurabh K Gupta; Saxena, Payal; Pant, Vandana A.; Pant, Aditya B.

    2012-01-01

    Dental resin composite that are tooth-colored materials have been considered as possible substitutes to mercury-containing silver amalgam filling. Despite the fact that dental resin composites have improved their physico-chemical properties, the concern for its intrinsic toxicity remains high. Some components of restorative composite resins are released in the oral environment initially during polymerization reaction and later due to degradation of the material. In vitro and in vivo studies h...

  8. Relative Molecular Mass Distribution of BG Resins

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Benzoguanamine-formaldehyde (BG-F) resins are a class of amino resins, which are important cross-linking agents for epoxy, alkyol and acrylic resins, etc. The cross-linking performance is the best one when the polymerization degree is 2-4. This paper discusses the effects of the pH value for polycondensation and the formaldehyde to benzoguanamine mole ratio in a methanol system, and compares the relative molecular mass distribution using the Flory statistics method.

  9. Amino acid adsorption on mesoporous materials: influence of types of amino acids, modification of mesoporous materials, and solution conditions.

    Science.gov (United States)

    Gao, Qiang; Xu, Wujun; Xu, Yao; Wu, Dong; Sun, Yuhan; Deng, Feng; Shen, Wanling

    2008-02-21

    In order to disclose the dominant interfacial interaction between amino acids and ordered mesoporous materials, the adsorption behaviors of five amino acids on four mesoporous materials were investigated in aqueous solutions with adjustable amino acid concentration, ion strength, and pH. The selected amino acids were acidic amino acid glutamic acid (Glu), basic amino acid arginine (Arg), and neutral amino acids phenylalanine (Phe), leucine (Leu), and alanine (Ala), and the selected mesoporous materials were SBA-15, Al-SBA-15, CH3(10%)-SBA-15, and CH3(20%)-SBA-15. The adsorption capacities of Glu and Arg were strongly dependent on pH and surface charge of the mesoporous adsorbent. The adsorption of Phe showed pH insensitivity but depended on the surface organic functionalization of mesoporous adsorbent. On the basis of the theoretical analysis about the interaction between amino acid and adsorbent, such a remarkable difference was attributed to the different nature of the interaction between amino acid and adsorbent. Arg could be readily adsorbed on the surface of SBA-15, especially Al-SBA-15, under appropriate pH in which the electrostatic interaction was predominant. The driving force of Phe adsorption on mesoporous adsorbent mainly came from the hydrophobic interaction. Therefore, the adsorption capability of Arg decreased with increasing ion strength of solution, while the adsorption capability of Phe increased with the increasing degree of CH3 functionalization on SBA-15. For neutral amino acid Phe, Ala, and Leu, the adsorption capability increased with the increase of the length of their side chains, which was another evidence of hydrophobic effect. Thus, all the adsorption of amino acids on mesoporous silica materials can be decided by the combined influence of two fundamental interactions: electrostatic attraction and hydrophobic effect.

  10. Curing Mechanism of Condensed Polynuclear Aromatic Resin and Thermal Stability of Cured Resin

    Institute of Scientific and Technical Information of China (English)

    Li Shibin; Sun Qiqian; Wang Yuwei; Wu Mingbo; Zhang Zailong

    2015-01-01

    In order to improve the thermal stability of condensed polynuclear aromatic (COPNA) resin synthesized from vacuum residue, 1,4-benzenedimethanol was added to cure COPNA resin. The curing mechanism was investigated by pro-ton nuclear magnetic resonance spectrometry, solid carbon-13 nuclear magnetic resonance spectrometry and Fourier trans-form infrared spectroscopy. Microstructures of the uncured and the cured COPNA resins were studied by scanning electron microscopy and X-ray diffractometry. The thermal stability of COPNA resins before and after curing was tested by thermo-gravimetric analysis. The element composition of the cured COPNA resin heated at different temperatures was analyzed by an element analyzer. The results showed that the uncured COPNA resin reacted with the cross-linking agent during the cur-ing process, and the curing mechanism was conifrmed to be the electrophilic substitution reaction. Compared with the un-cured COPNA resin, the cured COPNA resin had a smooth surface, well-ordered and streamlined sheet structure with more crystalline solids, better molecular arrangement and orientation. The weight loss process of the uncured and cured COPNA resins was divided into three stages. Carbon residue of the cured COPNA resin was 41.65%at 600℃, which was much higher than 25.02%of the uncured COPNA resin, which indicated that the cured COPNA resin had higher thermal stability.

  11. Damping Properties of Flexible Epoxy Resin

    Institute of Scientific and Technical Information of China (English)

    WANG Xiang; LIU Hanxing; OUYANG Shixi

    2008-01-01

    Amino-terminated polyethers and amino-terminated polyurethane were used as curing agent to cure the epoxy resin together and get a series of cured products. The damping properties of the composites were studied by DMA test at different measurement frequencies. Damping mechanical tests show that the flexible epoxy resin has higher loss factor than common epoxy. The highest loss factor reaches 1.57. Also the height and position of loss factor peak of the flexible epoxy resin varies by changing the content of amino-terminated polyethers. Results shows that the flexible epoxy resin can be used as damping polymer materials at room temperature or in common frequency range.

  12. Resin composites in minimally invasive dentistry.

    Science.gov (United States)

    Jacobsen, Thomas

    2004-01-01

    The concept of minimally invasive dentistry will provide favorable conditions for the use of composite resin. However, a number of factors must be considered when placing composite resins in conservatively prepared cavities, including: aspects on the adaptation of the composite resin to the cavity walls; the use of adhesives; and techniques for obtaining adequate proximal contacts. The clinician must also adopt an equally conservative approach when treating failed restorations. The quality of the composite resin restoration will not only be affected by the outline form of the preparation but also by the clinician's technique and understanding of the materials.

  13. Advanced resin systems for graphite epoxy composites

    Science.gov (United States)

    Gilwee, W. J.; Jayarajan, A.

    1980-01-01

    The value of resin/carbon fiber composites as lightweight structures for aircraft and other vehicle applications is dependent on many properties: environmental stability, strength, toughness, resistance to burning, smoke produced when burning, raw material costs, and complexity of processing. A number of woven carbon fiber and epoxy resin composites were made. The epoxy resin was commercially available tetraglycidylmethylene dianiline. In addition, composites were made using epoxy resin modified with amine and carboxyl terminated butadiene acrylonitrile copolymer. Strength and toughness in flexure as well as oxygen index flammability and NBS smoke chamber tests of the composites are reported.

  14. Formation of monodisperse mesoporous silica microparticles via spray-drying.

    Science.gov (United States)

    Waldron, Kathryn; Wu, Winston Duo; Wu, Zhangxiong; Liu, Wenjie; Selomulya, Cordelia; Zhao, Dongyuan; Chen, Xiao Dong

    2014-03-15

    In this work, a protocol to synthesize monodisperse mesoporous silica microparticles via a unique microfluidic jet spray-drying route is reported for the first time. The microparticles demonstrated highly ordered hexagonal mesostructures with surface areas ranging from ~900 up to 1500 m(2)/g and pore volumes from ~0.6 to 0.8 cm(3)/g. The particle size could be easily controlled from ~50 to 100 μm from the same diameter nozzle via changing the initial solute content, or changing the drying temperature. The ratio of the surfactant (CTAB) and silica (TEOS), and the amount of water in the precursor were found to affect the degree of ordering of mesopores by promoting either the self-assembly of the surfactant-silica micelles or the condensation of the silica as two competing processes in evaporation induced self-assembly. The drying rate and the curvature of particles also affected the self-assembly of the mesostructure. The particle mesostructure is not influenced by the inlet drying temperature in the range of 92-160 °C, with even a relatively low temperature of 92 °C producing highly ordered mesoporous microparticles. The spray-drying derived mesoporous silica microparticles, while of larger sizes and more rapidly synthesized, showed a comparable performance with the conventional mesoporous silica MCM-41 in controlled release of a dye, Rhodamine B, indicating that these spray dried microparticles could be used for the immobilisation and controlled release of small molecules.

  15. Diamine Functionalized Cubic Mesoporous Silica for Ibuprofen Controlled Delivery.

    Science.gov (United States)

    Sivaguru, J; Selvaraj, M; Ravi, S; Park, H; Song, C W; Chun, H H; Ha, C-S

    2015-07-01

    A diamine functionalized cubic mesostructured KIT-6 (N-KIT-6) has been prepared by post-synthetic method using calcined mesoporous KIT-6 with a diamine source, i.e., N-'[3-(tri methoxysilyl)- propyl]'ethylenediamine. The KIT-6 mesoporous silica used for N-KIT-6 was synthesized under weak acidic hydrothermal method using bitemplates, viz., Pluronic P123 and 1-butanol. The synthesized mesoporous materials, KIT-6 and N-KIT-6, have been characterized by the relevant instrumental techniques such as SAXS, N2 sorption isotherm, FT-IR, SEM, TEM and TGA to prove the standard mesoporous materials with the identification of diamine groups. The characterized mesoporous materials, KIT-6 and N-KIT-6, have been extensively used in the potential application of controlled drug delivery, where ibuprofen (IBU) employed as a model drug. The rate of IBU adsorption and release was monitored by UV vis-spectrometer. On the basis of the experimental results of controlled drug delivery system, the results of IBU adsorption and releasing rate in N-KIT-6 are higher than those of KIT-6 because of the higher hydrophobic nature as well as rich basic sites on the surface of inner pore wall silica.

  16. Organized thiol functional groups in mesoporous core shell colloids

    Energy Technology Data Exchange (ETDEWEB)

    Marchena, Martin H. [Gerencia Quimica, Centro Atomico Constituyentes, Comision Nacional de Energia Atomica (CNEA), Avda. Gral. Paz 1499, B1650KNA Buenos Aires (Argentina); Granada, Mara [Centro Atomico Bariloche-CNEA, 8400 San Carlos de Bariloche (Argentina); Instituto Balseiro-Centro Atomico Bariloche-CNEA, San Carlos de Bariloche 8400 (Argentina); Bordoni, Andrea V. [Gerencia Quimica, Centro Atomico Constituyentes, Comision Nacional de Energia Atomica (CNEA), Avda. Gral. Paz 1499, B1650KNA Buenos Aires (Argentina); Joselevich, Maria [Asociacion Civil Expedicion Ciencia, Cabrera 4948, C1414BGP Buenos Aires (Argentina); Troiani, Horacio [Centro Atomico Bariloche-CNEA, 8400 San Carlos de Bariloche (Argentina); Instituto Balseiro-Centro Atomico Bariloche-CNEA, San Carlos de Bariloche 8400 (Argentina); Williams, Federico J. [DQIAQyF-INQUIMAE FCEN, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon II, C1428EHA Buenos Aires (Argentina); Wolosiuk, Alejandro, E-mail: wolosiuk@cnea.gov.ar [Gerencia Quimica, Centro Atomico Constituyentes, Comision Nacional de Energia Atomica (CNEA), Avda. Gral. Paz 1499, B1650KNA Buenos Aires (Argentina)

    2012-03-15

    The co-condensation in situ of tetraethoxysilane (TEOS) and mercaptopropyltrimethoxysilane (MPTMS) using cetyltrimethylammonium bromide (CTAB) as a template results in the synthesis of multilayered mesoporous structured SiO{sub 2} colloids with 'onion-like' chemical environments. Thiol groups were anchored to an inner selected SiO{sub 2} porous layer in a bilayered core shell particle producing different chemical regions inside the colloidal layered structure. X-Ray Photoelectron Spectroscopy (XPS) shows a preferential anchoring of the -SH groups in the double layer shell system, while porosimetry and simple chemical modifications confirm that pores are accessible. We can envision the synthesis of interesting colloidal objects with defined chemical environments with highly controlled properties. - Graphical abstract: Mesoporous core shell SiO{sub 2} colloids with organized thiol groups. Highlights: Black-Right-Pointing-Pointer Double shell mesoporous silica colloids templated with CTAB. Black-Right-Pointing-Pointer Sequential deposition of mesoporous SiO{sub 2} layers with different chemistries. Black-Right-Pointing-Pointer XPS shows the selective functionalization of mesoporous layers with thiol groups.

  17. Mesoporous materials for clean energy technologies.

    Science.gov (United States)

    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.

  18. Mesoporous junctions and nanocrystalline solar cells

    Science.gov (United States)

    Graetzel, Michael

    2000-03-01

    Learning from the concepts used by green plants, we have developed a molecular photovoltaic system based on the sensitization of nanocrystalline TiO2 films. In analogy to photosyntesis, light is absorbed by a monolayer of dye attached to the surface of a wide-band-gap oxide. The mesoporous morphology of the layer provides a substrate characterized by a very large surface area. The roughness factor of a 10-micron thick film reaches easily 1000. Light penetrating the dye loaded TiO2 nanocrystals is therefore collected in an efficient manner, similar to the thylakoid vesicles in green leafs which are stacked in order to enhance solar light harvesting. The excited dye injects an electron in the conduction band of the oxide resulting in efficient and very rapid charge separation. Nearly quantitative conversion of photons in electric current have been achieved with these devices over the whole visible and near-IR range of the spectrum. The overall AM 1.5 solar-to electric power conversion efficiency has reached already 11unravel the dynamics of interfacial charge transfer reactions at these dye- sensitized heterojunctions.

  19. Photoluminescence of carbon dots from mesoporous silica

    Science.gov (United States)

    Nelson, D. K.; Razbirin, B. S.; Starukhin, A. N.; Eurov, D. A.; Kurdyukov, D. A.; Stovpiaga, E. Yu; Golubev, V. G.

    2016-09-01

    Photophysical properties of carbon dots were investigated under various excitation conditions and over a wide temperature region - from room to liquid helium temperatures. The carbon dots (CDs) were synthesized using mesoporous silica particles as a reactor and (3-aminopropyl)triethoxysilane (APTES) as a precursor. The photoluminescence spectra of CDs exhibit a strong dependence on the excitation wavelength and demonstrate a significant inhomogeneous broadening. Lowering sample temperature reveals the doublet structure of the spectra, which is associated with the vibronic structure of radiative transitions. The vibration energy ∼1200 cm-1 is close to the energy of Csbnd O stretching vibration. Long-lived phosphorescence of carbon dots with its decay time ∼0.2 s at T = 80 K was observed. The fluorescence and phosphorescence spectra are shown to be spectrally separated. The long-lived component of the emission was ascribed to optically forbidden triplet-singlet transitions. The value of the singlet-triplet splitting was found to be about 0.3 eV. Photo-induced polarization of the luminescence of carbon dots was revealed. The degree of the linear polarization is dependent on the wavelengths of both excitation and emitted light. The effect indicates a hidden anisotropy of optical dipole transitions in the dots and demonstrates the loss of the dipole orientation during the electron energy relaxation.

  20. Preliminary Synthesis and Characterization of Mesoporous Nanocrystalline Zirconia

    Institute of Scientific and Technical Information of China (English)

    Xinmei Liu; Gaoqing Lu; Zifeng Yan

    2003-01-01

    A novel method to prepare mesoporous nano-zirconia was developed. The synthesis was carried out in the presence of PEO surfactants via a solid-state reaction. The materials exhibit a strong diffraction peak at low 2θ angle and their nitrogen adsorption/desorption isotherms are typical of type Ⅳ with H1 hysteresis loops. The pore structure imaged by TEM can be described as wormhole domains.The tetragonal zirconia nanocrystals are uniform in size (around 1.5 nm) and their mesopores focus on around 4.6 nm. The zirconia nanocrystal growth is tentatively postulated to be the result of an aggregation mechanism. This study also reveals that the PEO surfactants can interact with the Zr-O-Zr framework to reinforce the thermal stability of zirconia. The ratio of NaOH to ZrOC12, crystallization and calcination temperature play an important role in the synthesis of mesoporous nano-zirconia.

  1. Mesoporous materials for energy conversion and storage devices

    Science.gov (United States)

    Li, Wei; Liu, Jun; Zhao, Dongyuan

    2016-06-01

    To meet the growing energy demands in a low-carbon economy, the development of new materials that improve the efficiency of energy conversion and storage systems is essential. Mesoporous materials offer opportunities in energy conversion and storage applications owing to their extraordinarily high surface areas and large pore volumes. These properties may improve the performance of materials in terms of energy and power density, lifetime and stability. In this Review, we summarize the primary methods for preparing mesoporous materials and discuss their applications as electrodes and/or catalysts in solar cells, solar fuel production, rechargeable batteries, supercapacitors and fuel cells. Finally, we outline the research and development challenges of mesoporous materials that need to be overcome to increase their contribution in renewable energy applications.

  2. Syntheses and applications of periodic mesoporous organosilica nanoparticles

    KAUST Repository

    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.

  3. Mesoporous silica and organosilica films templated by nanocrystalline chitin.

    Science.gov (United States)

    Nguyen, Thanh-Dinh; Shopsowitz, Kevin E; MacLachlan, Mark J

    2013-11-04

    Liquid crystalline phases can be used to impart order into inorganic solids, creating materials that mimic natural architectures. Herein, mesoporous silica and organosilica films with layered structures and high surface areas have been templated by nanocrystalline chitin. Aqueous suspensions of spindle-shaped chitin nanocrystals were prepared by sequential deacetylation and hydrolysis of chitin fibrils isolated from king crab shells. The nanocrystalline chitin self-assembles into a nematic liquid-crystalline phase that has been used to template silica and organosilica composites. Removal of the chitin template by either calcination or sulfuric-acid-catalyzed hydrolysis gave mesoporous silica and ethylene-bridged organosilica films. The large, crack-free mesoporous films have layered structures with features that originate from the nematic organization of the nanocrystalline chitin.

  4. Electrochemical Hydrogen Storage in a Highly Ordered Mesoporous Carbon

    Directory of Open Access Journals (Sweden)

    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.

  5. Synthesis of mesoporous silica microsphere from dual surfactant

    Directory of Open Access Journals (Sweden)

    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.

  6. Highly Aminated Mesoporous Silica Nanoparticles with Cubic Pore Structure

    KAUST Repository

    Suteewong, Teeraporn

    2011-01-19

    Mesoporous silica with cubic symmetry has attracted interest from researchers for some time. Here, we present the room temperature synthesis of mesoporous silica nanoparticles possessing cubic Pm3n symmetry with very high molar ratios (>50%) of 3-aminopropyl triethoxysilane. The synthesis is robust allowing, for example, co-condensation of organic dyes without loss of structure. By means of pore expander molecules, the pore size can be enlarged from 2.7 to 5 nm, while particle size decreases. Adding pore expander and co-condensing fluorescent dyes in the same synthesis reduces average particle size further down to 100 nm. After PEGylation, such fluorescent aminated mesoporous silica nanoparticles are spontaneously taken up by cells as demonstrated by fluorescence microscopy.

  7. Mesoporous NiO-Samaria doped ceria fuel cell materials.

    Science.gov (United States)

    Eom, Tae Wook; Kim, Kyung Hwan; Kim, Jong Sung; Jo, Myung-Chan; Yoon, Hyon Hee; Park, Sang Joon

    2009-02-01

    The mesoporous NiO-SDC was synthesized using a cationic surfactant (cetyl-trimethylammonium bromide; CTAB) for obtaining wide triple-phase boundary (TPB) in solid oxide fuel cells (SOFCs). The microstructure of mesoporous NiO-SDC was characterized by XRD, SEM, BET, and HRTEM and the results showed that the mesoporous NiO-SDC with 6.3 nm pores could be obtained. After calcined at 600 degrees C, the surface area of NiO-SDC was 206 m2/g, which was sufficiently high for providing large TPB in SOFC anode. In addition, FT-IR measurements revealed that Ni(OH)2 and SDC were incorporated with amine group of CTAB.

  8. Dentine sealing provided by smear layer/smear plugs vs. adhesive resins/resin tags.

    Science.gov (United States)

    Carrilho, Marcela R; Tay, Franklin R; Sword, Jeremy; Donnelly, Adam M; Agee, Kelli A; Nishitani, Yoshihiro; Sadek, Fernanda T; Carvalho, Ricardo M; Pashley, David H

    2007-08-01

    The aim of this study was to evaluate the ability of five experimental resins, which ranged from hydrophobic to hydrophilic blends, to seal acid-etched dentine saturated with water or ethanol. The experimental resins (R1, R2, R3, R4, and R5) were evaluated as neat bonding agents (100% resin) or as solutions solvated with absolute ethanol (70% resin/30% ethanol). Fluid conductance was measured at 20 cm H(2)O hydrostatic pressure after sound dentine surfaces were: (i) covered with a smear layer; (ii) acid-etched; or (iii) bonded with neat or solvated resins, which were applied to acid-etched dentine saturated with water or ethanol. In general, the fluid conductance of resin-bonded dentine was significantly higher than that of smear layer-covered dentine. However, when the most hydrophobic neat resins (R1 and R2) were applied to acid-etched dentine saturated with ethanol, the fluid conductance was as low as that produced by smear layers. The fluid conductance of resin-bonded dentine saturated with ethanol was significantly lower than for resin bonded to water-saturated dentine, except for resin R4. Application of more hydrophobic resins may provide better sealing of acid-etched dentine if the substrate is saturated with ethanol instead of with water.

  9. Ordered mesoporous silica (OMS) as an adsorbent and membrane for separation of carbon dioxide (CO2).

    Science.gov (United States)

    Chew, Thiam-Leng; Ahmad, Abdul L; Bhatia, Subhash

    2010-01-15

    Separation of carbon dioxide (CO(2)) from gaseous mixture is an important issue for the removal of CO(2) in natural gas processing and power plants. The ordered mesoporous silicas (OMS) with uniform pore structure and high density of silanol groups, have attracted the interest of researchers for separation of carbon dioxide (CO(2)) using adsorption process. These mesoporous silicas after functionalization with amino groups have been studied for the removal of CO(2). The potential of functionalized ordered mesoporous silica membrane for separation of CO(2) is also recognized. The present paper reviews the synthesis of mesoporous silicas and important issues related to the development of mesoporous silicas. Recent studies on the CO(2) separation using ordered mesoporous silicas (OMS) as adsorbent and membrane are highlighted. The future prospectives of mesoporous silica membrane for CO(2) adsorption and separation are also presented and discussed.

  10. Mesoporous bioactive glass scaffolds for efficient delivery of vascular endothelial growth factor.

    Science.gov (United States)

    Wu, Chengtie; Fan, Wei; Chang, Jiang; Xiao, Yin

    2013-09-01

    In this article, we, for the first time, investigated mesoporous bioactive glass scaffolds for the delivery of vascular endothelial growth factor. We have found that mesoporous bioactive glass scaffolds have significantly higher loading efficiency and more sustained release of vascular endothelial growth factor than non-mesoporous bioactive glass scaffolds. In addition, vascular endothelial growth factor delivery from mesoporous bioactive glass scaffolds has improved the viability of endothelial cells. The study has suggested that mesopore structures in mesoporous bioactive glass scaffolds play an important role in improving the loading efficiency, decreasing the burst release, and maintaining the bioactivity of vascular endothelial growth factor, indicating that mesoporous bioactive glass scaffolds are an excellent carrier of vascular endothelial growth factor for potential bone tissue engineering applications.

  11. MODIFICATION OF X-5 RESIN AND ADSORPTION PROPERTY OF THE MODIFIED RESINS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Three polymeric adsorbents with hydrogen bonding acceptors, methylamine,N-methyl-acetamide and aminotri(hydroxymethyl)methane modified resins are synthesized fromchloromethylated X-5 resin. Adsorption isotherms of phenol and theophylline onto the three modifiedresins and the original X-5 resin from aqueous solution are measured. The results show thatadsorption of compounds with hydrogen bonding donor onto methylamine and N-methylacetamidemodified resins is enhanced as compared with that onto X-5 resin, and adsorption mechanismbetween the adsorbents and the adsorbates is mainly based on hydrogen bonding and hydrophobicinteraction. While adsorption of compounds with hydrogen bonding donor ontoaminotri(hydroxymethyl)methane modified resin is lowered as compared with that onto X-5 resin, andadsorption mechanism between the adsorbent and the adsorbates is mainly based on hydrophobicinteraction.

  12. Novel silica-based ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Gula, M.; Harvey, J.

    1996-12-31

    Shortcomings of chelating resins have been addressed by a new class of ion exchange resins called dual mechanism bifunctional polymers (DMBPs). DMBPs use hydrophilic cation exchange ligands with rapid uptake kinetics and use chelating ligands for selectivity for one or more metals; result is a resin that quickly recognizes and removes targeted metals from waste, remediation, and process streams. Eichrom`s Diphonix {reg_sign} resin is the first DMBP to be widely released as a commercial product; it is polystyrene based. Objective of this work is to synthesize commercial quantities of a silica-based ion exchange resin with the same or better metal ion selectivity, metal uptake kinetics, and acid stability as Diphonix. Feasibility was determined, however the process needs to be optimized. Studies at Eichrom and ANL of the performance of Diphonix resin over a broad range of HNO3 and HCl conditions and inorganic salt loadings are discussed together with the proposed method of incorporating similar characteristics into a silica-based resin. The new, silica-based resin functionalized with diphosphonic acid ligands can be used in environmental restoration and waste management situations involving processing of low-level, transuranic, and high-level radioactive wastes; it can also be used for processing liquid mixed waste including wastes contaminated with organic compounds.

  13. Dental resin cure monitoring by inherent fluorescence

    Science.gov (United States)

    Li, Qun; Zhou, Jack X.; Li, Qingxiong; Wang, Sean X.

    2008-02-01

    It is demonstrated that the inherent fluorescence of a dental composite resin can be utilized to monitor the curing status, i.e. degree of conversion of the resin. The method does not require any sample preparation and is potentially very fast for real time cure monitoring. The method is verified by Raman spectroscopy analysis.

  14. TMI-2 purification demineralizer resin study

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, J D; Osterhoudt, T R

    1984-05-01

    Study of the Makeup and Purification System demineralizers at TMI-2 has established that fuel quantities in the vessels are low, precluding criticality, that the high radioactive cesium concentration on the demineralizer resins can be chemically removed, and that the demineralizer resins can probably be removed from the vessels by sluicing through existing plant piping. Radiation measurements from outside the demineralizers establishing that there is between 1.5 and 5.1 (probably 3.3) lb of fuel in the A vessel and less than that amount in the B vessel. Dose rates up to 2780 R per hour were measured on contact with the A demineralizer. Remote visual observation of the A demineralizer showed a crystalline crust overlaying amber-colored resins. The cesium activity in solid resin samples ranged from 220 to 16,900 ..mu..Ci/g. Based on this information, researchers concluded that the resins cannot be removed through the normal pathway in their present condition. Studies do show that the resins will withstand chemical processing designed to rinse and elute cesium from the resins. The process developed should work on the TMI-2 resins.

  15. [Delayed asthma bronchiale due to epoxy resin].

    Science.gov (United States)

    Authried, Georg; Al-Asadi, Haifaa; Møller, Ulla; Sherson, David Lee

    2013-10-28

    Epoxy resin is a low molecular weight agent, which can cause both acute and delayed allergic reactions. However, it is known causing skin reactions with direct or airborne contact. Rarely it can cause airway reactions like asthma bronchiale. We describe a case of a windmill worker who developed delayed asthma bronchiale due to airborne contact with epoxy resin.

  16. Optical and electronic loss analysis of mesoporous solar cells

    Science.gov (United States)

    Kovalsky, Anton; Burda, Clemens

    2016-07-01

    We review the art of complete optical and electronic characterization of the popular mesoporous solar cell motif. An overview is given of how the mesoporous paradigm is applied to solar cell technology, followed by a discussion on the variety of techniques available for thoroughly probing efficiency leaching mechanisms at every stage of the energy transfer pathway. Some attention is dedicated to the rising importance of computational results to augment loss analysis due to the complexity of solar cell devices, which have emergent properties that are important to account for, but difficult to measure, such as parasitic absorption.

  17. Simple Preparation of Novel Metal-Containing Mesoporous Starches

    Directory of Open Access Journals (Sweden)

    Rafael Luque

    2013-05-01

    Full Text Available Metal-containing mesoporous starches have been synthesized using a simple and efficient microwave-assisted methodology followed by metal impregnation in the porous gel network. Final materials exhibited surface areas >60 m2 g−1, being essentially mesoporous with pore sizes in the 10–15 nm range with some developed inter-particular mesoporosity. These materials characterized by several techniques including XRD, SEM, TG/DTA and DRIFTs may find promising catalytic applications due to the presence of (hydroxides in their composition.

  18. Macroporous silica–alumina composites with mesoporous walls

    Indian Academy of Sciences (India)

    Gautam Gundiah

    2001-04-01

    Macroporous silica–alumina composites with mesopores have been prepared by employing polymethylmethacrylate beads as templates in the presence of the cationic surfactant, N-cetyl-N,N,N-trimethylammonium bromide. The Si/Al ratio in the composites has been varied between 4.5 and 48 and the occurrence of mesopores has been verified by X-ray diffraction. The surface areas of the samples vary between 676 and 1038 m2g–1, with the highest value in the sample with Si/Al = 48.

  19. Electric Field-Responsive Mesoporous Suspensions: A Review

    Directory of Open Access Journals (Sweden)

    Seung Hyuk Kwon

    2015-12-01

    Full Text Available This paper briefly reviews the fabrication and electrorheological (ER characteristics of mesoporous materials and their nanocomposites with conducting polymers under an applied electric field when dispersed in an insulating liquid. Smart fluids of electrically-polarizable particles exhibit a reversible and tunable phase transition from a liquid-like to solid-like state in response to an external electric field of various strengths, and have potential applications in a variety of active control systems. The ER properties of these mesoporous suspensions are explained further according to their dielectric spectra in terms of the flow curve, dynamic moduli, and yield stress.

  20. Functionalized periodic mesoporous organosilicas: Hierarchical and chiral materials

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The integration of organic and inorganic fragments within the pore walls of the periodic mesoporous organosilicas (PMOs) represents one of the recent breakthroughs in material science. The resulting PMOs are promising materials for applications in such areas as catalysis, adsorption, separation and drug-delivery. We summarize here the recent progress made in the synthesis of PMOs with hierarchical structures and large functional groups, with special emphasis on the chiral mesoporous organosilicas and their potential applications as novel chiral solids in heterogeneous asymmetric catalysis.

  1. Container effect in nanocasting synthesis of mesoporous metal oxides.

    Science.gov (United States)

    Sun, Xiaohong; Shi, Yifeng; Zhang, Peng; Zheng, Chunming; Zheng, Xinyue; Zhang, Fan; Zhang, Yichi; Guan, Naijia; Zhao, Dongyuan; Stucky, Galen D

    2011-09-21

    We report a general reaction container effect in the nanocasting synthesis of mesoporous metal oxides. The size and shape of the container body in conjunction with simply modifying the container opening accessibility can be used to control the escape rate of water and other gas-phase byproducts in the calcination process, and subsequently affect the nanocrystal growth of the materials inside the mesopore space of the template. In this way, the particle size, mesostructure ordering, and crystallinity of the final product can be systemically controlled. The container effect also explain some of the problems with reproducibility in previously reported results.

  2. Release and toxicity of dental resin composite.

    Science.gov (United States)

    Gupta, Saurabh K; Saxena, Payal; Pant, Vandana A; Pant, Aditya B

    2012-09-01

    Dental resin composite that are tooth-colored materials have been considered as possible substitutes to mercury-containing silver amalgam filling. Despite the fact that dental resin composites have improved their physico-chemical properties, the concern for its intrinsic toxicity remains high. Some components of restorative composite resins are released in the oral environment initially during polymerization reaction and later due to degradation of the material. In vitro and in vivo studies have clearly identified that these components of restorative composite resins are toxic. But there is a large gap between the results published by research laboratories and clinical reports. The objective of this manuscript was to review the literature on release phenomenon as well as in vitro and in vivo toxicity of dental resin composite. Interpretation made from the recent data was also outlined.

  3. Posterior adhesive composite resin: a historic review.

    Science.gov (United States)

    Fusayama, T

    1990-11-01

    Since development of the BIS-GMA composite resin, there have been many innovations to improve the physical properties for posterior use. Subsequent development of a caries detector and chemically adhesive composite resin has further revolutionally raised the value of composite resin restoration, replacing the traditional restorative system of mechanical approach by the new system of biological approach. In this system only the infected irreversibly deteriorated insensitive tissue, stainable with the caries detector, is removed painlessly. The cavity is immediately filled with the composite resin with no further tissue reduction for retention or resistance form or extension for prevention. Both enamel and dentin walls are etched by a single etchant without lining. The chemical adhesion to the cavity margin and wall minimizes the marginal failure in size and prevalence and prevents secondary caries penetration along the wall. The chemically adhesive composite resin is thus a useful restorative material much kinder to teeth than amalgam.

  4. EPOXY RESINS TOUGHENED WITH CARBOXYL TERMINATED POLYETHERS

    Institute of Scientific and Technical Information of China (English)

    YU Yunchao; LI Yiming

    1983-01-01

    Carboxyl terminated polyethers, the adducts of hydroxyl terminated polytetrahydrofuran and maleic anhydride, were used as toughener for epoxy resins. The morphology of the toughened resins was investigated by means of turbidity measurement, dynamic mechanical testing and scanning electron microscope observation. It turned out that the molecular weight and the carboxyl content of the polyether and the cure conditions are important factors, which affect the particle size of the polyether-rich domains and, in turn, the mechanical properties of the cured resin. Carboxyl terminated polytetrahydrofurans have a low glass transition temperature, and in appropriate amount they do not affect the thermal resistance of the resin. These advantages make them preferable as toughener for epoxy resins.

  5. Reinforcement of Denture Base Resins

    Directory of Open Access Journals (Sweden)

    T Nejatiant

    2005-10-01

    Full Text Available Introduction: PMMA has been the most popular denture base material because of its advantages including good aesthetics, accurate fit, stability in the oral environment, easy laboratory and clinical manipulation and inexpensive equipments since the 1930’s. However, its fracture resistance is not satisfactory. Aim: The aim of this study is to improve the fracture resistance of denture bases made of PMMA by assessing the effect of resin type, packing and processing variables on biaxial flexural strength (BFS. Materials & methods: 930 discs, 12 mm diameter and 2 mm thick were prepared with the following variables: a. Veined (V and Plain (P PMMA. b. 5 different powder/liquid ratios by volume (1.5:1, 2:1, 2.5:1, 3:1, 3.5:1. c. Conventional (C and Injection packing methods (I. d. Dry heat (D Water bath (W; and e. different curing times. The discs were trimmed and stored in 37°C tap water for 50 hours before carrying out BFS test, according to BS EN ISO 1567: 2001. BFS test was carried out using a tensile-testing machine (Lloyd LRX, Lloyd instruments Ltd (Figure.1 b, with a x-head speed of 1mm/min. ONE-WAY ANOVA analysis and TUKEY’S comparison were carried out (MINITAB. The temperature within the curing baths and inside of curing resin was evaluated by using a thermocouple. Results: BFS of Powder/liquid ratio of 1.5:1 is significantly lower than the other four ratios. Among the last four ratios, 2.5:1 was the strongest one although the difference was not significant. BFS of the plain type of PMMA is significantly higher than the veined type.• BFS of conventionally packed PMMA discs was greater than the injectional packed ones and the difference is significant. Water bath cured resin showed a significant higher BFS compared with dry heat curing. • Changing the curing time in the dry heat bath from 7h @ 75º C and 2hrs @ 95º C to 5hrs @ 75º C and 3hrs @ 95º C and then 2hrs @ 95º C improves BFS of PMMA. In the water bath the trend is identical

  6. Organosulfonic acid-functionalized mesoporous composites based on natural rubber and hexagonal mesoporous silica

    Energy Technology Data Exchange (ETDEWEB)

    Nuntang, Sakdinun; Poompradub, Sirilux [Fuels Research Center, Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Patumwan, Bangkok 10330 (Thailand); Butnark, Suchada [PTT Research and Technology Institute, PTT Public Company Limited, Wangnoi, Ayutthaya 13170 (Thailand); Yokoi, Toshiyuki; Tatsumi, Takashi [Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan); Ngamcharussrivichai, Chawalit, E-mail: Chawalit.Ng@Chula.ac.th [Fuels Research Center, Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Patumwan, Bangkok 10330 (Thailand); Center of Excellence on Petrochemical and Materials Technology (PETROMAT), Chulalongkorn University, Patumwan, Bangkok 10330 (Thailand)

    2014-10-15

    This study is the first report on synthesis, characterization and catalytic application of propylsulfonic acid-functionalized mesoporous composites based on natural rubber (NR) and hexagonal mesoporous silica (HMS). In comparison with propylsulfonic acid-functionalized HMS (HMS-SO{sub 3}H), a series of NR/HMS-SO{sub 3}H composites were prepared via an in situ sol–gel process using tetrahydrofuran as the synthesis media. Tetraethylorthosilicate as the silica source, was simultaneously condensed with 3-mercaptopropyltrimethoxysilane in a solution of NR followed by oxidation with hydrogen peroxide to achieve the mesoporous composites containing propylsulfonic acid groups. Fourier-transform infrared spectroscopy and {sup 29}Si MAS nuclear magnetic resonance spectroscopy results verified that the silica surfaces of the NR/HMS-SO{sub 3}H composites were functionalized with propylsulfonic acid groups and covered with NR molecules. After the incorporation of NR and organo-functional group into HMS, the hexagonal mesostructure remained intact concomitantly with an increased framework wall thickness and unit cell size, as evidenced by the X-ray powder diffraction analysis. Scanning electron microscopy analysis indicated a high interparticle porosity of NR/HMS-SO{sub 3}H composites. The textural properties of NR/HMS-SO{sub 3}H were affected by the amount of MPTMS loading to a smaller extent than that of HMS-SO{sub 3}H. NR/HMS-SO{sub 3}H exhibited higher hydrophobicity than HMS-SO{sub 3}H, as revealed by H{sub 2}O adsorption–desorption measurements. Moreover, the NR/HMS-SO{sub 3}H catalysts possessed a superior specific activity to HMS-SO{sub 3}H in the esterification of lauric acid with ethanol, resulting in a higher conversion level. - Highlights: • Acidic NR/HMS-SO{sub 3}H composites were prepared by in situ sol–gel process. • Propylsulfonic acid was functionalized onto HMS surface by direct co-condensation. • NR/HMS-SO{sub 3}H exhibited a hexagonal

  7. Structure Property Relationships of Biobased Epoxy Resins

    Science.gov (United States)

    Maiorana, Anthony Surraht

    The thesis is about the synthesis, characterization, development, and application of epoxy resins derived from sustainable feedstocks such as lingo-cellulose, plant oils, and other non-food feedstocks. The thesis can be divided into two main topics 1) the synthesis and structure property relationship investigation of new biobased epoxy resin families and 2) mixing epoxy resins with reactive diluents, nanoparticles, toughening agents, and understanding co-curing reactions, filler/matrix interactions, and cured epoxy resin thermomechanical, viscoelastic, and dielectric properties. The thesis seeks to bridge the gap between new epoxy resin development, application for composites and advanced materials, processing and manufacturing, and end of life of thermoset polymers. The structures of uncured epoxy resins are characterized through traditional small molecule techniques such as nuclear magnetic resonance, high resolution mass spectrometry, and infrared spectroscopy. The structure of epoxy resin monomers are further understood through the process of curing the resins and cured resins' properties through rheology, chemorheology, dynamic mechanical analysis, tensile testing, fracture toughness, differential scanning calorimetry, scanning electron microscopy, thermogravimetric analysis, and notched izod impact testing. It was found that diphenolate esters are viable alternatives to bisphenol A and that the structure of the ester side chain can have signifi-cant effects on monomer viscosity. The structure of the cured diphenolate based epoxy resins also influence glass transition temperature and dielectric properties. Incorporation of reactive diluents and flexible resins can lower viscosity, extend gel time, and enable processing of high filler content composites and increase fracture toughness. Incorpora-tion of high elastic modulus nanoparticles such as graphene can provide increases in physical properties such as elastic modulus and fracture toughness. The synthesis

  8. Adsorption behaviors of a novel carbonyl and hydroxyl groups modified hyper-cross-linked poly(styrene-co-divinylbenzene) resin for beta-naphthol from aqueous solution.

    Science.gov (United States)

    He, Chunlian; Huang, Jianhan; Yan, Cheng; Liu, Jianbo; Deng, Linbei; Huang, Kelong

    2010-08-15

    A series of novel hyper-cross-linked resins were synthesized from macroporous cross-linked chloromethylated poly(styrene-co-divinylbenzene) by adding different dosage of hydroquinone in Friedel-Crafts reaction. The results of the pore structures revealed that the prepared resins possessed micropores, mesopores and macropores, and the chloromethyl groups and the uploaded hydroquinone were partly oxidized according to the results of Fourier-transformed infrared ray spectra. Among these hydroquinone modified resins, HJ-Y06 resin held the largest adsorption capacity for beta-naphthol, and its adsorption capacity was comparable with XAD-4 while much larger than X-5. The adsorption kinetics could be characterized by pseudo-second-order rate equation and intra-particle diffusion model was the rate-limiting step at the initial process. The adsorption was favorable at solution pH lower than 6.5. The adsorption isotherms could be fitted by Langmuir model and the adsorption was an endothermic process. Hydrogen bonding between formaldehyde carbonyl and quinone carbonyl groups on HJ-Y06 and phenolic hydroxyl groups of beta-naphthol was the main driving force for the adsorption.

  9. Core/shell magnetic mesoporous silica nanoparticles with radially oriented wide mesopores

    Directory of Open Access Journals (Sweden)

    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.

  10. Enhanced photocatalytic properties in well-ordered mesoporous WO3

    KAUST Repository

    Li, Li

    2010-01-01

    We used polyisoprene-block-ethyleneoxide copolymers as structure-directing agents to synthesise well-ordered and highly-crystalline mesoporous WO 3 architectures that possess improved photocatalytic properties due to enhanced dye-adsorption in absence of diffusion limitation. © 2010 The Royal Society of Chemistry.

  11. Chemical modification/grafting of mesoporous alumina with polydimethylsiloxane (PDMS)

    NARCIS (Netherlands)

    Pinheiro de Melo, A.F.; Nijmeijer, A.; Sripathi, V.G.P.; Winnubst, A.J.A.

    2015-01-01

    A method for polydimethylsiloxane grafting of alumina powders is described which involves chemical modification of the surface of mesoporous (5 nm) γ-alumina flakes with a linker (3-aminopropyltriethoxysilane: APTES), either by a solution phase (SPD) or a vapour phase (VPD) reaction, followed by PDM

  12. Mesopore quality determines the lifetime of hierarchically structured zeolite catalysts

    Science.gov (United States)

    Milina, Maria; Mitchell, Sharon; Crivelli, Paolo; Cooke, David; Pérez-Ramírez, Javier

    2014-05-01

    Deactivation due to coking limits the lifetime of zeolite catalysts in the production of chemicals and fuels. Superior performance can be achieved through hierarchically structuring the zeolite porosity, yet no relation has been established between the mesopore architecture and the catalyst lifetime. Here we introduce a top-down demetallation strategy to locate mesopores in different regions of MFI-type crystals with identical bulk porous and acidic properties. In contrast, well-established bottom-up strategies as carbon templating and seed silanization fail to yield materials with matching characteristics. Advanced characterization tools capable of accurately discriminating the mesopore size, distribution and connectivity are applied to corroborate the concept of mesopore quality. Positron annihilation lifetime spectroscopy proves powerful to quantify the global connectivity of the intracrystalline pore network, which, as demonstrated in the conversions of methanol or of propanal to hydrocarbons, is closely linked to the lifetime of zeolite catalysts. The findings emphasize the need to aptly tailor hierarchical materials for maximal catalytic advantage.

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

    DEFF Research Database (Denmark)

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

    2007-01-01

    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...

  14. Incorporation of anti-inflammatory agent into mesoporous silica

    Science.gov (United States)

    Rodrigues Braz, Wilson; Lamec Rocha, Natállia; de Faria, Emerson H.; Silva, Márcio L. A. e.; Ciuffi, Katia J.; Tavares, Denise C.; Furtado, Ricardo Andrade; Rocha, Lucas A.; Nassar, Eduardo J.

    2016-09-01

    The unique properties of macroporous, mesoporous, and microporous systems, including their ability to accommodate molecules of different sizes inside their pores and to act as drug delivery systems, have been the object of extensive studies. In this work, mesoporous silica with hexagonal structure was obtained by template synthesis via the sol-gel process. The resulting material was used as support to accommodate the anti-inflammatory agent indomethacin. The alkaline route was used to prepare the mesoporous silica; cetyltrimethylammonium bromide was employed as porogenic agent. The silica particles were functionalized with 3-aminopropyltriethoxysilane alkoxide (APTES) by the sol-gel post-synthesis method. Indomethacin was incorporated into the silica functionalized with APTES and into non-functionalized silica. The resulting systems were characterized by x-ray diffraction (XRD), specific area, infrared spectroscopy, and thermal analyses (TGA). XRD attested to formation of mesoporous silica with hexagonal structure. This structure remained after silica functionalization with APTES and incorporation of indomethacin. Typical infrared spectroscopy vibrations and organic material decomposition during TGA confirmed silica functionalization and drug incorporation. The specific surface area and pore volume of the functionalized material incorporated with indomethacin decreased as compared with the specific surface area and pore volume of the non-functionalized silica containing no drug, suggesting both the functionalizing agent and the drug were present in the silica. Cytotoxicity tests conducted on normal fibroblasts (GM0479A) cells attested that the silica matrix containing indomethacin was less toxic than the free drug.

  15. Synthesis of ordered mesoporous uranium dioxide by a nanocasting route

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Ran; Wang Lin; Shi, Wei-Qun [Chinese Academy of Sciences, Beijing (China). Laboratory of Nuclear Energy Chemistry and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety; Chai, Zhi-Fang [Chinese Academy of Sciences, Beijing (China). Laboratory of Nuclear Energy Chemistry and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety; Soochow Univ., Suzhou (China). School of Radiological and Interdisciplinary Sciences and Collaborative Innovation Center

    2016-11-01

    Ordered mesoporous UO{sub 2} with 3-D structure (for UO{sub 2}-KIT-6) and nanowire bundles (for UO{sub 2}-SBA-15) was synthesized for the first time by a nanocasting route using different ordered mesoporous silica (KIT-6 and SBA-15, respectively) as templates and uranyl nitrate hexahydrate as the metal precursor. The uranyl nitrate was impregnated into the mesopore of the silica template and was converted to U{sub 3}O{sub 8} after the first step. The synthesis of ordered UO{sub 2} mesostructure was achieved by reducing the mesoporous U{sub 3}O{sub 8} with silica composites under 5% H{sub 2}/Ar atmosphere at 700 C, followed by a template removal process. The as-prepared UO{sub 2}-KIT-6 had a particle size of several millimeters, and was constructed with uncoupled subframework mesostructure and crystalline walls, while UO{sub 2}-SBA-15 possessed a rope-like morphology and consisted of nanowire arrays. The surface area and pore volume of ordered UO{sub 2} mesostructure are 47.2 m{sup 2} g{sup -1} and 0.23 cm{sup 3} g{sup -1} for the UO{sub 2}-KIT-6, and 54.4 m{sup 2} g{sup -1} and 0.28 cm{sup 3} g{sup -1} for the UO{sub 2}-SBA-15, respectively.

  16. Synthesis and characterization of molybdenum incorporated mesoporous aluminophosphate

    Science.gov (United States)

    Ho, Li-Ngee; Ikegawa, Tasuku; Nishiguchi, Hiroyasu; Nagaoka, Katsutoshi; Takita, Yusaku

    2006-07-01

    A synthesis of molybdenum incorporated mesoporous aluminophosphate with long-chain n-alkylamine as template material had been prepared under non-aqueous condition. These materials were extensively characterized by using X-ray diffraction (XRD), nitrogen sorption isotherms, nuclear magnetic resonance of 27Al and 31P (NMR), inductive coupled plasma (ICP), electron spin resonance (ESR), Fourier transform infrared (FTIR) and thermogravimetric-differential thermal analysis (TG-DTA). Morphology of the materials had been observed by using transmission electron microscope (TEM) that revealed the mesoporous materials possessed wormhole-like structures. Alkaline solvent extraction using n-butylamine/ethanol had been efficiently removed the n-alkylamine from the mesoporous samples which yielded BET surface areas around 550-730 m 2/g. BJH analysis showed a narrow pore size distribution which increased with increasing of the carbon chain length of alkylamine (template). Valence state and coordination of the molybdenum in the obtained samples were investigated by using ESR and FTIR where it was found that Mo 4+ and Mo 6+ molybdenum species existed in the molybdenum incorporated mesoporous aluminophosphate in tetrahedral coordination.

  17. Fabrication of mesoporous silica/polymer composites through solvent evaporation process and investigation of their excellent low thermal expansion property.

    Science.gov (United States)

    Suzuki, Norihiro; Kiba, Shosuke; Yamauchi, Yusuke

    2011-03-21

    We fabricate mesoporous silica/epoxy polymer composites through a solvent evaporation process. The easy penetration of the epoxy polymers into mesopores is achieved by using a diluted polymer solution including a volatile organic solvent. After the complete solvent evaporation, around 90% of the mesopores are estimated to be filled with the epoxy polymer chains. Here we carefully investigate the thermal expansion behavior of the obtained mesoporous silica/polymer composites. Thermal mechanical analysis (TMA) charts revealed that coefficient of linear thermal expansion (CTE) gradually decreases, as the amount of the doped mesoporous silica increases. Compared with spherical silica particle without mesopores, mesoporous silica particles show a greater effect on lowering the CTE values. Interestingly, it is found that the CTE values are proportionally decreased with the decrease of the total amount of the polymers outside the mesopores. These data demonstrate that polymers embedded inside the mesopores become thermally stable, and do not greatly contribute to the thermal expansion behavior of the composites.

  18. 76 FR 4936 - Granular Polytetrafluoroethylene Resin From Italy

    Science.gov (United States)

    2011-01-27

    ... COMMISSION Granular Polytetrafluoroethylene Resin From Italy AGENCY: United States International Trade... antidumping duty order on granular polytetrafluoroethylene resin (``granular PTFE resin'') from Italy. DATES... on granular PTFE resin from Italy and Japan (75 FR 67082-67083 and 67105-67108, November 1,...

  19. 21 CFR 177.2490 - Polyphenylene sulfide resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyphenylene sulfide resins. 177.2490 Section 177... Components of Articles Intended for Repeated Use § 177.2490 Polyphenylene sulfide resins. Polyphenylene sulfide resins (poly(1,4-phenylene sulfide) resins) may be safely used as coatings or components...

  20. 21 CFR 177.2450 - Polyamide-imide resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyamide-imide resins. 177.2450 Section 177.2450... Components of Articles Intended for Repeated Use § 177.2450 Polyamide-imide resins. Polyamide-imide resins...) For the purpose of this section the polyamide-imide resins are derived from the condensation...

  1. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylonitrile copolymers and resins. 181.32 Section... Ingredients § 181.32 Acrylonitrile copolymers and resins. (a) Acrylonitrile copolymers and resins listed in... of the vinyl chloride resin) resin—for use only in contact with oleomargarine. (iv)...

  2. Restorative resins: abrasion vs. mechanical properties.

    Science.gov (United States)

    Jørgensen, K D

    1980-12-01

    The purpose of the present work was to examine whether it is possible by simple and reliable laboratory tests to evaluate the abrasion by food of Class 1 restorative resins. The results point to the following main conclusions: for the smooth-surface resins, i.e. the micro-filled composite and the unfilled resins, the Wallace hardness test appears to be a valid parameter for abrasion; the greater the depth of penetration of the Vickers diamond of this apparatus, the more severe abrasion is to be expected. The mode of abrasion in this type of resin is scratching. Porosity in the resins strongly enhances the abrasion. For the rough-surface resins, i.e. the conventional composites, a dual effect of the filler particles was concluded. The filler particles on the one hand protect the matrix against abrasion, but cause, on the other hand, in time an increase of the surface roughness of the composite and thereby via increased friction an increase of the abrasion. Considerations on possible ways to improve the present-day restorative resins are presented. It is stressed that the results obtained refer only to abrasion of Class 1 fillings by food.

  3. Cobalt Ions Improve the Strength of Epoxy Resins

    Science.gov (United States)

    Stoakley, D. M.; St. Clair, A. K.

    1986-01-01

    Technique developed for improving mechanical strength of epoxy resins by adding cobalt ions in form of tris(acetylacetonato)cobalt (III) complex. Solid cast disks prepared from cobalt ion-containing epoxy resins tested for flexural strength and stiffness. Incorporation of cobalt ions into epoxies increased flexural strength of resins by 10 to 95 percent. Suitable resins for this technique include any liquid or solid TGMDA resins. Improved epoxy formulation proves useful as composite matrix resin, adhesive, or casting resin for applications on commercial and advanced aircraft.

  4. Phenolic resin-based porous carbons for adsorption and energy storage applications

    Science.gov (United States)

    Wickramaratne, Nilantha P.

    The main objective of this dissertation research is to develop phenolic resin based carbon materials for range of applications by soft-templating and Stober-like synthesis strategies. Applications Studied in this dissertation are adsorption of CO2, bio-molecular and heavy metal ions, and energy storage devices. Based on that, our goal is to design carbon materials with desired pore structure, high surface area, graphitic domains, incorporated metal nanoparticles, and specific organic groups and heteroatoms. In this dissertation the organic-organic self-assembly of phenolic resins and triblock copolymers under acidic conditions will be used to obtain mesoporous carbons/carbon composites and Stober-like synthesis involving phenolic resins under basic condition will be used to prepare polymer/carbon particles and their composites. The structure of this dissertation consists of an introductory chapter (Chapter 1) discussing the general synthesis of carbon materials, particularly the soft-templating strategy and Stober-like carbon synthesis. Also, Chapter 1 includes a brief outline of applications namely adsorption of CO2, biomolecule and heavy metal ions, and supercapacitors. Chapter 2 discusses the techniques used for characterization of the carbon materials studied. This chapter starts with nitrogen adsorption analysis, which is used to measure the specific surface area, pore volume, distribution of pore sizes, and pore width. In addition to nitrogen adsorption, powder X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution thermogravimetric analysis (HR-TGA), cyclic voltammetry (CV) and CHNS elemental analysis (EA) are mentioned too. Chapter 3 is focused on carbon materials for CO2 adsorption. There are different types of porous solid materials such as silicate, MOFs, carbons, and zeolites studied for CO2 adsorption. However, the carbon based materials are considered to be the best candidates for CO 2 adsorption to the industrial point of

  5. EP-toxicity test of saturated GT-73 resin and resin in grout

    Energy Technology Data Exchange (ETDEWEB)

    Bibler, J.P.

    1985-04-24

    The results of EP-toxicity tests on mercury saturated Duolite{reg_sign} GT-73 cation exchange resin clarify options for the ultimate disposal of spent resin. Samples of GT-73 saturated with mercury passed the EP-toxicity test, indicating that fully spent resin may be classifed as ``solid``-not``hazardous``-waste and stored or disposed-of as such. Samples of GT-73 resin saturated with mercury and then incorporated into Portland Type 1 cement did not pass the EP-toxicity test and fall into the ``hazardous waste`` category. Samples of GT-73 resin less-than-saturated with mercury which were in corporated in Portland Type 1 cement passed the EP-toxicity test and may be classified as ``solid waste.`` Other commercially available materials are being investigated for incorporating fully spent GT-73 resin in a solid waste form.

  6. The flexible resin transfer molding (FRTM) process

    Science.gov (United States)

    Foley, Michael F.

    1992-12-01

    An innovative composite manufacturing process, FRTM, which is based on detailed cost analysis intended to be 'cost effective by design', is described. FRTM is based on a combination of the technical characteristics and respective favorable economics of diaphragm forming, and resin transfer molding. The process control system determines the optimal time for compaction and forming using an empirical resin polymerization model, a fluid flow model, and dielectric sensing of in-situ resin properties. The modified FRTM process is capable of producing high-quality parts with low thickness variation, low void content, and high fiber volume.

  7. Advanced Fibre Reinforced Methyl Nadicimide Resins .

    Directory of Open Access Journals (Sweden)

    Sarfaraz Alam

    1996-07-01

    Full Text Available Glass/carbon/kevlar-reinforced composites were fabricated using two structurally different methl nadicimide resins. The resin content of the laminates was in the range of 32-39 per cent. Interlaminar shear strength (ILSSand flexual strength (FS depended on the structure of the methyl nadicimide resins. A significant decrease in the ILSS was observed on treatment with boiling water for 500 h and on isothermal ageing at 300 degree celsius for 100,250 and 500 h. The limiting oxygen index (LOI was the lowest for laminates based on Kevlar fabrics (i.e.54 whereas the laminates based on glass/carbon showed very high LOI(>90.

  8. Luminous Efficient Compositions Based on Epoxy Resin

    Directory of Open Access Journals (Sweden)

    R.S. Palaiah

    2006-07-01

    Full Text Available Magnesium/sodium nitrate illuminating compositions with epoxy resin - E 605 have beenstudied for luminosity and luminous efficiency by varying fuel oxidizer ratio and binder content.The compositions have been evaluated for impact and friction sensitivities, burn rate, thermalcharacteristics, and mechanical properties. Flame temperature and combustion products areevaluated theoretically by using REAL program. Experimental results show that, luminosity,burn rate, and calorimetric value are higher for polyester resin-based compositions. The highluminous efficiency composition is achieved with magnesium/sodium nitrate ratio of 70/30 with4 per cent epoxy resin.

  9. Textural manipulation of mesoporous materials for hosting of metallic nanocatalysts.

    Science.gov (United States)

    Sun, Junming; Bao, Xinhe

    2008-01-01

    The preparation and stabilization of nanoparticles are becoming very crucial issues in the field of so-called "nanocatalysis". Recent developments in supramolecular self-assembled porous materials have opened a new way to get nanoparticles hosted in the channels of such materials. In this paper, a new approach towards monodisperse and thermally stable metal nanoparticles by confining them in ordered mesoporous materials is presented, and three aspects are illustrated. Firstly, the recent progress in the functional control of mesoporous materials will be briefly introduced, and the rational tuning of the textures, pore size, and pore length is demonstrated by controlling supramolecular self-assembly behavior. A novel synthesis of short-pore mesoporous materials is emphasized for their easy mass transfer in both biomolecule absorption and the facile assembly of metal nanocomposites within their pore channels. In the second part, the different routes for encapsulating monodisperse nanoparticles inside channels of porous materials are discussed, which mainly includes the ion-exchange/conventional incipient wetness impregnation, in situ encapsulation routes, organometallic methodologies, and surface functionalization schemes. A facile in situ autoreduction route is highlighted to get monodisperse metal nanoparticles with tunable sizes inside the channels of mesoporous silica. Finally, confinement of mesoporous materials is demonstrated to improve the thermal stability of monodisperse metal nanoparticles catalysts and a special emphasis will be focused on the stabilization of the metal nanoparticles with a low Tammann temperature. Several catalytic reactions concerning the catalysis of nanoparticles will be presented. These uniform nanochannels, which confine monodisperse and stable metal nanoparticles catalysts, are of great importance in the exploration of size-dependent catalytic chemistry and further understanding the nature of catalytic reactions.

  10. Magnetic mesoporous materials for removal of environmental wastes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byoung Chan; Lee, Jinwoo; Um, Wooyong; Kim, Jaeyun; Joo, Jin; Lee, Jin Hyung; Kwak, Ja Hun; Kim, Jae Hyun; Lee, Changha; Lee, Hongshin; Addleman, Raymond S.; Hyeon, Taeghwan; Gu, Man Bock; Kim, Jungbae

    2011-09-15

    We have synthesized two different magnetic mesoporous materials that can be easily separated from aqueous solutions by applying a magnetic field. Synthesized magnetic mesoporous materials, Mag-SBA-15 (magnetic ordered mesoporous silica) and Mag-OMC (magnetic ordered mesoporous carbon), have a high loading capacity of contaminants due to high surface area of the supports and high magnetic activity due to the embedded iron oxide particles. Application of surface-modified Mag-SBA-15 was investigated for the collection of mercury from water. The mercury adsorption using Mag-SBA-15 was rapid during the initial contact time and reached a steady-state condition, with an uptake of approximately 97% after 7 hours. Application of Mag-OMC for collection of organics from water, using fluorescein as an easily trackable model analyte, was explored. The fluorescein was absorbed into Mag-OMC within minutes and the fluorescent intensity of solution was completely disappeared after an hour. In another application, Mag-SBA-15 was used as a host of tyrosinase, and employed as recyclable catalytic scaffolds for tyrosinase-catalyzed biodegradation of catechol. Tyrosinase aggregates in Mag-SBA-15, prepared in a two step process of tyrosinase adsorption and crosslinking, could be used repeatedly for catechol degradation with no serious loss of enzyme activity. Considering these results of cleaning up water from toxic inorganic, organic and biochemical contaminants, magnetic mesoporous materials have a great potential to be employed for the removal of environmental contaminants and potentially for the application in large-scale wastewater treatment plants.

  11. 5-year clinical performance of resin composite versus resin modified glass ionomer restorative system in non-carious cervical lesions

    DEFF Research Database (Denmark)

    Franco, Eduardo Batista; Benetti, Ana Raquel; Ishikiriama, Sérgio Kiyoshi

    2006-01-01

    To comparatively assess the 5-year clinical performance of a 1-bottle adhesive and resin composite system with a resin-modified glass ionomer restorative in non-carious cervical lesions.......To comparatively assess the 5-year clinical performance of a 1-bottle adhesive and resin composite system with a resin-modified glass ionomer restorative in non-carious cervical lesions....

  12. Magnetic ion-exchange resin treatment: Impact of water type and resin use

    OpenAIRE

    Mergen, Maxime Rodolphe Denis; Jefferson, Bruce; Parsons, Simon A.; Jarvis, Peter

    2008-01-01

    Three raw waters of fundamentally different natural organic matter (NOM) character were treated by magnetic resin using a bench-scale method designed to mimic how the resin is used in continuous operation. Increasing water hydrophobicity resulted in reduced dissolved organic carbon (DOC) removal with removal of 56%, 33% and 25% for waters containing 21%, 50% and 75% hydrophobic NOM, respectively. Study of consecutive resin uses showed that the NOM in the hydrophobic water ha...

  13. Compaction and Cure of Resin Film Infusion Prepregs

    OpenAIRE

    Thompson, Joseph E.

    2004-01-01

    Gutowski et al.'s model has been employed to describe the cure and consolidation of prepregs used for resin film infusion. Resin kinetics, rheology, flow and fiber deformation are considered. Resin kinetics are simulated with an isothermal autocatalytic-1 type relation. The non-Newtonian viscosity of the Cytec™ 754 resin is represented with a gel type expression. The one dimensional flow of resin through a deformable, partially saturated porous medium is studied. A nonlinear partial...

  14. Multitasking mesoporous nanomaterials for biorefinery applications

    Energy Technology Data Exchange (ETDEWEB)

    Kandel, Kapil [Iowa State Univ., Ames, IA (United States)

    2013-01-01

    Mesoporous silica nanoparticles (MSNs) have attracted great interest for last two decades due to their unique and advantageous structural properties, such as high surface area, pore volume, stable mesostructure, tunable pore size and controllable particle morphology. The robust silica framework provides sites for organic modifications, making MSNs ideal platforms for adsorbents and supported organocatalysts. In addition, the pores of MSNs provide cavities/ channels for incorporation of metal and metal oxide nanoparticle catalysts. These supported metal nanoparticle catalysts benefit from confined local environments to enhance their activity and selectivity for various reactions. Biomass is considered as a sustainable feedstock with potential to replace diminishing fossil fuels for the production of biofuels. Among several strategies, one of the promising methods of biofuel production from biomass is to reduce the oxygen content of the feedstock in order to improve the energy density. This can be achieved by creating C-C bonds between biomass derived intermediates to increase the molecular weight of the final hydrocarbon molecules. In this context, pore size and organic functionality of MSNs are varied to obtain the ideal catalyst for a C-C bond forming reaction: the aldol condensation. The mechanistic aspects of this reaction in supported heterogeneous catalysts are explored. The modification of supported organocatalyst and the effect of solvent on the reaction are rationalized. The significance of two functional surfaces of MSNs is exploited by enzyme immobilization on the external surface and organo catalyst functionalization on the internal surface. Using this bifunctional catalyst, the tandem conversion of small chain alcohols into longer chain hydrocarbon molecules is demonstrated. The ability to incorporate metal and metal oxide nanoparticles in the pores and subsequent functionalization led to develop organic modified magnetic MSNs (OM-MSNs) for applications

  15. Ordered mesoporous carbon film as an effective solid-phase microextraction coating for determination of benzene series from aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Hui [Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); School of Geography Science, Nantong University, Nantong 226001 (China); Li, Jiansheng, E-mail: lijsh@mail.njust.edu.cn [Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Jiang, Mingyue; Lu, Rui; Shen, Jinyou; Sun, Xiuyun; Han, Weiqing [Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Wang, Lianjun, E-mail: wanglj@mail.njust.edu.cn [Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China)

    2015-08-12

    The present work reports preparation of ordered mesoporous carbon (OMC) film supported on a graphite fiber as a new type of solid-phase microextraction (SPME) fiber for determination of benzene series from aqueous media. The strategy for the supported OMC film preparation was combined dip-coating technology with solvent evaporation-induced self-assembly (EISA) approach. A graphite fiber was immersed in an ethanol solution containing phenolic resin and Pluronic triblock copolymer. Upon solvent evaporation and subsequent pyrolysis under 700 °C, the phenolic resin and the surfactant self-assembled on the surface of the graphite fiber to form smooth OMC film. X-ray diffraction (XRD), transmission electron microscopy (TEM) and nitrogen isothermal adsorption results indicate that the resultant OMC film possesses well-ordered two dimensional hexagonal mesostructure with pore diameters of 4.5 nm and BET surfaces of 630 m{sup 2}/g. Scanning electron microscopy (SEM) studies show the supported OMC film with thickness at 8.5 μm is continuous and defect-free. The SPME efficiency of the OMC fiber was evaluated by analysis of five benzene series (benzene, toluene, ethylbenzene, p-xylene and m-xylene) from water samples by gas chromatography-flame ionization detection (GC-FID). The analysis results indicate that the prepared OMC fiber has wide linear ranges (0.5–500 μg/L), low detection limits (0.01–0.05 μg/L) and good repeatabilities (4.0–5.8% for one fiber, 2.9–8.7% for fiber-to-fiber). Compared with commercial counterparts, the OMC fiber exhibits improved extraction efficiency for benzene series and PAHs. - Highlights: • Ordered mesoporous carbon film supported on graphite fiber was first reported as solid-phase microextraction coating. • The strategy for the film preparation was combined dip-coating technology with evaporation-induced self-assembly approach. • The obtained fiber showed enhanced thermal stability and organic solvents resistance. • The

  16. Dental repair material: a resin-modified glass-ionomer bioactive ionic resin-based composite.

    Science.gov (United States)

    Croll, Theodore P; Berg, Joel H; Donly, Kevin J

    2015-01-01

    This report documents treatment and repair of three carious teeth that were restored with a new dental repair material that features the characteristics of both resin-modified glass-ionomer restorative cement (RMGI) and resin-based composite (RBC). The restorative products presented are reported by the manufacturer to be the first bioactive dental materials with an ionic resin matrix, a shock-absorbing resin component, and bioactive fillers that mimic the physical and chemical properties of natural teeth. The restorative material and base/liner, which feature three hardening mechanisms, could prove to be a notable advancement in the adhesive dentistry restorative materials continuum.

  17. Synthesis of mesoporous Beta and Sn-Beta zeolites and their catalytic performances.

    Science.gov (United States)

    Jin, Junjiang; Ye, Xinxin; Li, Yongsheng; Wang, Yanqin; Li, Liang; Gu, Jinlou; Zhao, Wenru; Shi, Jianlin

    2014-06-14

    Mesoporous Beta zeolite has been successfully prepared through hydrothermal synthesis in the presence of cationic ammonium-modified chitosan as the meso-template. Through a subsequent solid-gas reaction between highly dealuminated mesoporous Beta zeolite and SnCl4 steam at an elevated temperature, mesoporous Sn-Beta has been facilely obtained. It was revealed that the addition of cationic chitosan induced the nanocrystal aggregation to particle sizes of ∼300 nm, giving rise to the intercrystalline/interparticle mesoporosity. In the Sn-implanting procedure, Sn species were demonstrated to be doped into the framework of the resulting mesoporous Beta zeolite in a tetrahedral environment without structural collapse. Due to the micro/mesoporous structures, both mesoporous Beta and Sn-Beta exhibited superior performances in α-pinene isomerization, Baeyer-Villiger oxidation of 2-adamantanone by hydrogen peroxide and the isomerization of glucose in water, respectively.

  18. Direct coating of mesoporous titania on CTAB-capped gold nanorods

    Science.gov (United States)

    Zhao, Junwei; Xu, Pengyu; Li, Yue; Wu, Jian; Xue, Junfei; Zhu, Qiannan; Lu, Xuxing; Ni, Weihai

    2016-03-01

    We demonstrate a CTAB-templated approach towards direct coating of mesoporous titania on gold nanorods in aqueous solutions. The formation of the mesoporous shell is found to be closely correlated with CTAB concentration and the amount of the titania precursor. This approach can be readily extended to form mesoporous titania shells on other CTAB-capped nanoparticles.We demonstrate a CTAB-templated approach towards direct coating of mesoporous titania on gold nanorods in aqueous solutions. The formation of the mesoporous shell is found to be closely correlated with CTAB concentration and the amount of the titania precursor. This approach can be readily extended to form mesoporous titania shells on other CTAB-capped nanoparticles. Electronic supplementary information (ESI) available: Experimental details including chemicals, sample preparation, and characterization methods. UV-Vis extinction spectra, SEM images, and TEM images of AuNR@mTiO2 nanostructures. See DOI: 10.1039/c5nr05692f

  19. Light-cured resin for post patterns.

    Science.gov (United States)

    Waldmeier, M D; Grasso, J E

    1992-09-01

    A method of using light-cured acrylic resin as an alternative to the use of chemically-cured acrylic resins with elastomeric impressions for direct post patterns is presented. The GC Unifast LC acrylic resin is a powder/liquid type resin cured by exposure to visible light. The polymerization process has four stages before final curing: slurry, stringy, dough-like (plastic), and rubber-like (elastic). Advantages over current direct and indirect procedures include ease of manipulation of the material and no change in laboratory handling procedures. While in the dough-like state, the material can be contoured. In the rubber-like state, it is flexible to disengage from minor undercut areas.

  20. Indirect composite resin materials for posterior applications.

    Science.gov (United States)

    Shellard, E; Duke, E S

    1999-12-01

    Indirect composite resin restorations were introduced a number of years ago as possible alternatives to traditional metallic or ceramic-based indirect restorations. However, the earlier formulations did not provide evidence of improvement in mechanical and physical properties over chairside-placed direct composite resin materials. Because they required more tooth structure removal than direct restorations, their use became unpopular and was abandoned by most clinicians. Over the past few years, a new class of composite resin indirect materials has surfaced in the profession. Various technologies have been suggested as reinforcement mechanisms. Fibers, matrix modifications, and an assortment of innovations have been proposed for enhancing indirect composite resin restorations. Applications are from inlay restorations all the way to multi-unit fixed prostheses. This manuscript summarizes some of the progress made in this area. When available, data is presented to provide clinicians with guidelines and indications for the use of these materials.

  1. 21 CFR 177.1585 - Polyestercarbonate resins.

    Science.gov (United States)

    2010-04-01

    ... molecular weight of 27,000, as determined by gel permeation chromatography using polystyrene standards. (2.... (ii) Polyestercarbonate resins, when extracted with 50 percent (by volume) ethyl alcohol in...

  2. Amine chemistry. Update on impact on resin

    Energy Technology Data Exchange (ETDEWEB)

    Bachman, Gregory; Kellogg, Douglas [Siemens Industry, Inc., Rockford, IL (United States). Technology and Lab Services; Wilkes, Marty [Siemens Industry, Inc., Rockford, IL (United States). Water Technologies Div.

    2012-03-15

    Impurity removal in the steam cycle and the associated prevention of corrosion and/or fouling of system components are the goals of ion exchange resins. However, in many instances (such as a switch to amine chemistry or a change in product specifications), resins do not remove, and, in fact, contribute impurities to the steam cycle. This paper reviews recent data compiled to determine the direct and indirect effects of amines on ion exchange resins used in the power industry. Water chemistries have improved in recent years, in large part due to changes in chemistry and resins, but it is necessary to continue to develop products, processes and techniques to reduce impurities and improve overall water chemistry in power plant systems. (orig.)

  3. Phenolic Resin Sector Enters New Stage

    Institute of Scientific and Technical Information of China (English)

    Pu Zeshuang

    2007-01-01

    @@ Rapid output increase With the importation of new production technologies and the boom of large timber processing, insulation refractory material, composite material and foam plastics sectors in recent years, the phenolic resin production in China has developed rapidly.

  4. Contraction stresses of composite resin filling materials.

    Science.gov (United States)

    Hegdahl, T; Gjerdet, N R

    1977-01-01

    The polymerization shrinkage of composite resin filling materials and the tensile stresses developed when the shrinkage is restrained were measured in an in vitro experiment. This allows an estimation to be made of the forces exerted upon the enamel walls of cavities filled with the resin in the acid etch technique. The results indicate that the stresses acting on the enamel are low compared to the tensile strength of the enamel.

  5. Volumetric polymerization shrinkage of contemporary composite resins

    Directory of Open Access Journals (Sweden)

    Halim Nagem Filho

    2007-10-01

    Full Text Available The polymerization shrinkage of composite resins may affect negatively the clinical outcome of the restoration. Extensive research has been carried out to develop new formulations of composite resins in order to provide good handling characteristics and some dimensional stability during polymerization. The purpose of this study was to analyze, in vitro, the magnitude of the volumetric polymerization shrinkage of 7 contemporary composite resins (Definite, Suprafill, SureFil, Filtek Z250, Fill Magic, Alert, and Solitaire to determine whether there are differences among these materials. The tests were conducted with precision of 0.1 mg. The volumetric shrinkage was measured by hydrostatic weighing before and after polymerization and calculated by known mathematical equations. One-way ANOVA (a or = 0.05 was used to determine statistically significant differences in volumetric shrinkage among the tested composite resins. Suprafill (1.87±0.01 and Definite (1.89±0.01 shrank significantly less than the other composite resins. SureFil (2.01±0.06, Filtek Z250 (1.99±0.03, and Fill Magic (2.02±0.02 presented intermediate levels of polymerization shrinkage. Alert and Solitaire presented the highest degree of polymerization shrinkage. Knowing the polymerization shrinkage rates of the commercially available composite resins, the dentist would be able to choose between using composite resins with lower polymerization shrinkage rates or adopting technical or operational procedures to minimize the adverse effects deriving from resin contraction during light-activation.

  6. Clinical applications of preheated hybrid resin composite.

    Science.gov (United States)

    Rickman, L J; Padipatvuthikul, P; Chee, B

    2011-07-22

    This clinical article describes and discusses the use of preheated nanohybrid resin composite for the placement of direct restorations and luting of porcelain laminate veneers. Two clinical cases are presented. Preheating hybrid composite decreases its viscosity and film thickness offering the clinician improved handling. Preheating also facilitates the use of nanohybrid composite as a veneer luting material with relatively low polymerisation shrinkage and coefficient of thermal expansion compared to currently available resin luting cements.

  7. Biocompatibility of Resin-based Dental Materials

    OpenAIRE

    Keyvan Moharamzadeh; Ian M. Brook; Richard van Noort

    2009-01-01

    Oral and mucosal adverse reactions to resin-based dental materials have been reported. Numerous studies have examined thebiocompatibility of restorative dental materials and their components, and a wide range of test systems for the evaluation of the biological effects of these materials have been developed. This article reviews the biological aspects of resin-based dental materials and discusses the conventional as well as the new techniques used for biocompatibility assessment of dental mat...

  8. Preliminary Study of Performance of TTA Resin

    Institute of Scientific and Technical Information of China (English)

    HUANG; Kun; MAO; Guo-shu

    2013-01-01

    TTA(thenoyl trifluoroacetone)extraction can effectively remove large amounts of uranium in the analysis of trace neptunium in the presence of large amounts of uranium.While it is not conducive to achieve the automation of the rapid analysis of neptunium with the TTA solution,the TTA resin was prepared and its properties were studied in this work.TTA resin in this work was a kind of mixture combining styrene-divinylbenzene skeleton with TTA

  9. Resin composites : Sandwich restorations and curing techniques

    OpenAIRE

    Lindberg, Anders

    2005-01-01

    Since the mid-1990s resin composite has been used for Class II restorations in stress-bearing areas as an alternative to amalgam. Reasons for this were the patients’ fear of mercury in dental amalgam and a growing demand for aesthetic restorations. During the last decades, the use of new resin composites with more optimized filler loading have resulted in reduced clinical wear. Improved and simplified amphiphilic bonding systems have been introduced. However, one of the main problems with res...

  10. Magnetic Resonance Studies of Epoxy Resins.

    Science.gov (United States)

    1980-12-07

    cyclohexanedicarboxylic anhydride (CHCA) with tripropylamine (TPA), and the MY720 was cured with DDH. The calculated stoichiometric mixtures for the systems ...investigate main-chain molecular motions in the epoxy resins tetraglycidyldiaminodiphenylmethane (TGDDM) and diglycidyl ether of bisphenol A (DGEBA) cured ...elimination reaction to release a stable nitroxide spin probe. In the dry cured epoxy resins at each temperature, the EPR lineshapes of the spin labels

  11. Graphitic mesoporous carbon based on aromatic polycondensation as catalyst support for oxygen reduction reaction

    Science.gov (United States)

    Liu, Peng; Kong, Jiangrong; Liu, Yaru; Liu, Qicheng; Zhu, Hongze

    2015-03-01

    Mesoporous carbon is constructed by monolithic polyaromatic mesophase deriving from the hexane insoluble of coal-tar pitch. This carbon material exhibits spherical morphology and layered crystallite, and thereby can be graphitized at 900 °C without destroying the mesoporous structure. Electrochemical measurements indicate that graphitic mesoporous carbon (GMC) support not only improves the activity of Pt electrocatalyst to oxygen reduction reaction (ORR), but also shows higher corrosion resistance than commercial XC-72 carbon black in the acid cathode environment.

  12. Selective adsorption and release of cationic organic dye molecules on mesoporous borosilicates

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Manidipa; Pal, Nabanita; Bhaumik, Asim, E-mail: msab@iacs.res.in

    2012-08-01

    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: Black-Right-Pointing-Pointer Highly ordered 2D-hexagonal mesoporous borosilicate. Black-Right-Pointing-Pointer Nonionic Pluoronic P123 templated mesoporous material. Black-Right-Pointing-Pointer Adsorption of organic dyes at the mesopore surface. Black-Right-Pointing-Pointer Controlled release of dyes under physiological pH and temperature. Black-Right-Pointing-Pointer Release of safranine T (ST) and malachite green (MG) dyes in simulated body fluids.

  13. Non-surfactant synthesis of mesoporous silica with dye as template

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A novel non-surfactant method was described to synthesize mesoporous silica using dye basic fuchsin as template. Chemical reactions were introduced into the formation of mesopores rather than the weak electrostatic or hydrogen-bonding interactions in the traditional surfactant routes. The reactant composition was found to be crucial to the pore structure of objective product. The formation mechanism of mesopore was also proved.

  14. Using mesoporous carbon electrodes for brackish water desalination.

    Science.gov (United States)

    Zou, Linda; Li, Lixia; Song, Huaihe; Morris, Gayle

    2008-04-01

    Electrosorptive deionisation is an alternative process to remove salt ions from the brackish water. The porous carbon materials are used as electrodes. When charged in low voltage electric fields, they possess a highly charged surface that induces adsorption of salt ions on the surface. This process is reversible, so the adsorbed salt ions can be desorbed and the electrode can be reused. In the study, an ordered mesoporous carbon (OMC) electrode was developed for electrosorptive desalination. The effects of pore arrangement pattern (ordered and random) and pore size distribution (mesopores and micropores) on the desalination performance was investigated by comparing OMC and activated carbon (AC). It were revealed from X-ray diffraction and N(2) sorption measurements that AC has both micropores and mesopores, whereas ordered mesopores are dominant in OMC. Their performance as potential electrodes to remove salt was evaluated by cyclic voltammetry (CV) and galvanostatic charge/discharge tests at a range of electrolyte concentrations and sweep rates. It is deduced that under the same electrochemical condition the specific capacitance values of OMC electrode (i.e. 133 F/g obtained from CV at a sweep rate of 1 mV/s in 0.1M NaCl solution) are larger than those of AC electrode (107 F/g), suggesting that the former has a higher desalting capacity than the latter. Furthermore, the OMC electrode shows a better rate capacity than the AC electrode. In addition, the desalination capacities were quantified by the batch-mode experiment at low voltage of 1.2V in 25 ppm NaCl solution (50 micros/cm conductivity). It was found that the adsorbed ion amounts of OMC and AC electrodes were 11.6 and 4.3 micromol/g, respectively. The excellent electrosorptive desalination performance of OMC electrode might be not only due to the suitable pore size (average of 3.3 nm) for the propagation of the salt ions, but also due to the ordered mesoporous structure that facilitates desorption of the

  15. Morphological Control of Multifunctional Mesoporous Silica Nanomaterials for Catalysis Applications

    Energy Technology Data Exchange (ETDEWEB)

    Huh, Seong [Iowa State Univ., Ames, IA (United States)

    2004-12-19

    I found an efficient method to control the morphology of the organically monofunctionalized mesoporous silica materials by introducing different types of organoalkoxysilanes in a base-catalyzed co-condensation reaction. The monofunctionalized materials exhibit different particle morphologies relative to the pure MCM-41 material. The concentration dependence of the morphology is a critical factor to determine the final particle shape. A proposed mechanism of the shape evolution is also offered. After understanding the role of organoalkoxysilanes in producing various well-shaped nanomaterials, I also obtained a series of bifunctional mesoporous silica materials with certain particle morphology. A series of bifunctional mesoporous silica nanospheres (MSNs) whose physicochemical properties was investigated via solid state NMR techniques and Cu2+ adsorption capacity tests, The ratio of two different organic groups inside of mesopores of these MSNs could be fine-tuned. These MSNs serve as a useful model system to study substrate selectivity in catalytic reactions and sorption phenomena. For example, the Cu2+ adsorption capacity of these materials was dictated by the chemical nature of the mesopores generated by the different organic functional groups. An investigation of the substrate selectivity of the bifunctionalized MSNs in a competitive nitroaldol reaction using an equimolar amount of two competing 4-nitrobenzaldehyde derivatives was performed. Shape-controlled bifunctional MSNs were employed as the catalysts. The properties of the MSNs were investigated using various spectroscopic methods and electron microscopy. The more hydrophobic the surface organic groups are, the higher the ratio of hydrophobic final product. This is the first example to demonstrate the selection of substrate using physicochemical nature of the mesopore surface other than the conventional shape selection in zeolite systems. I also created a cooperative dual catalyst

  16. Aromatization of Ethanol Over Desilicated ZSM-5 Zeolites: Effect of Pore Size in the Mesoporous Region.

    Science.gov (United States)

    Jun, Jong Won; Hasan, Zubair; Kim, Chul-Ung; Jeong, Soon-Yong; Jhung, Sung Hwa

    2016-05-01

    Mesoporous ZSM-5 zeolites were obtained from microporous ZSM-5 by desilication using aqueous NaOH solutions, and their catalytic activity in the aromatization of ethanol was investigated in order to understand the effects of pore size, in the mesoporous region, on the product distribution and stability of the catalysts. Mesopores generally enhanced the selectivities towards aromatics and stability for aromatization. Mesopores with a maximum pore diameter of around 13 nm were the most effective in the aromatization process (especially for benzene and toluene), suggesting that pore-diameter optimization is necessary for efficient catalysis such as aromatization.

  17. Single-Crystal Mesoporous ZnO Thin Films Composed of Nanowalls

    KAUST Repository

    Wang, Xudong

    2009-02-05

    This paper presents a controlled, large scale fabrication of mesoporous ZnO thin films. The entire ZnO mesoporous film is one piece of a single crystal, while high porosity made of nanowalls is present. The growth mechanism was proposed in comparison with the growth of ZnO nanowires. The ZnO mesoporous film was successfully applied as a gas sensor. The fabrication and growth analysis of the mesoporous ZnO thin film gi ve general guidance for the controlled growth of nanostructures. It also pro vides a unique structure with a superhigh surface-to-volume ratio for surface-related applications. © 2009 American Chemical Society.

  18. Breakthrough and future: nanoscale controls of compositions, morphologies, and mesochannel orientations toward advanced mesoporous materials.

    Science.gov (United States)

    Yamauchi, Yusuke; Suzuki, Norihiro; Radhakrishnan, Logudurai; Wang, Liang

    2009-01-01

    Currently, ordered mesoporous materials prepared through the self-assembly of surfactants have attracted growing interests owing to their special properties, including uniform mesopores and a high specific surface area. Here we focus on fine controls of compositions, morphologies, mesochannel orientations which are important factors for design of mesoporous materials with new functionalities. This Review describes our recent progress toward advanced mesoporous materials. Mesoporous materials now include a variety of inorganic-based materials, for example, transition-metal oxides, carbons, inorganic-organic hybrid materials, polymers, and even metals. Mesoporous metals with metallic frameworks can be produced by using surfactant-based synthesis with electrochemical methods. Owing to their metallic frameworks, mesoporous metals with high electroconductivity and high surface areas hold promise for a wide range of potential applications, such as electronic devices, magnetic recording media, and metal catalysts. Fabrication of mesoporous materials with controllable morphologies is also one of the main subjects in this rapidly developing research field. Mesoporous materials in the form of films, spheres, fibers, and tubes have been obtained by various synthetic processes such as evaporation-mediated direct templating (EDIT), spray-dried techniques, and collaboration with hard-templates such as porous anodic alumina and polymer membranes. Furthermore, we have developed several approaches for orientation controls of 1D mesochannels. The macroscopic-scale controls of mesochannels are important for innovative applications such as molecular-scale devices and electrodes with enhanced diffusions of guest species.

  19. [Classification and several mechanical properties of core composite resins].

    Science.gov (United States)

    Yamada, T; Hosoda, H; Tsurugai, T

    1990-03-01

    According to the classification proposed by Hosoda, six core resins could be divided into two categories on the basis of the elemental composition and size distribution of filler particles by SEM observation and EDX analysis. Furthermore, several mechanical properties of the resins were determined. The following facts were found: Bell Feel Core, Clearfil Core, Clearfil PhotoCore, Core Max, and Core Max II resins were classified as a semihybrid resin, and Microrest Core resin as a hybrid type resin. The elements detected in the resins by the EDX were Si, Zr, Al, Ba and La. The mechanical properties of the resins were shown to be highly stable at one day or one week after curing. The mechanical properties of the resins suggest that the subsequent crown preparation and impression taking should be postponed until the next appointment.

  20. Imide modified epoxy matrix resins

    Science.gov (United States)

    Scola, D. A.

    1984-01-01

    The results of a program designed to develop tough imide modified epoxy resins cured by bisimide amine (BIA) hardeners are described. State-of-the-art epoxides MY720 and DER383 were used, and four bismide amines were evaluated. These were the BIA's derived from the 6F anhydride (4,4'-(hexafluoroisopropylidene) bis(phthalic anhydride) and the diamines 3,3'-diaminodiphynyl sulfone, 4,4'-oxygianiline, 4,4'-methylene dianiline, and 1,12-dodecane diamine. A key intermediate, designated 6F anhydride, is required for the synthesis of the bisimide amines. Reaction parameters to synthesize a precursor to the 6F anhydride (6FHC) in high yields were investigated. The catalyst trifluoromethane sulfonic acid was studied. Although small scale runs yielded the 6FHC in 50 percent yield, efforts to ranslate these results to a larger scale synthesis gave the 6FHC in only 9 percent yield. Results show that the concept of using bisimide amine as curing agents to improve the toughness properties of epoxies is valid.

  1. PREPARATION OF MESOPOROUS CARBON BY CARBON DIOXIDE ACTIVATION WITH CATALYST

    Institute of Scientific and Technical Information of China (English)

    W.Z.Shen; A.H.Lu; J.T.Zheng

    2002-01-01

    A mesoporous activated carbon (AC) can be successfully prepared by catalytic activa-tion with carbon dioxide. For iron oxide as catalyst, there were two regions of mesoporesize distribution, i.e. 2-5nm and 30-70nm. When copper oxide or magnesium oxidecoexisted with iron oxide as composite catalyst, the content of pores with sizes of 2-5nm was decreased, while the pores with 30 70nm were increased significantly. Forcomparison, AC reactivated by carbon dioxide directly was also investigated. It wasshown that the size of mesopores of the resulting AC concentrated in 2-5nm with lessvolume. The adsorption of Congo red was tested to evaluate the property of the result-ing AC. Furthermore, the factors affecting pore size distribution and the possibility ofmesopore formation were discussed.

  2. Chemoradiotherapeutic wrinkled mesoporous silica nanoparticles for use in cancer therapy

    Directory of Open Access Journals (Sweden)

    Imalka Munaweera

    2014-11-01

    Full Text Available Over the last decade, the development and application of nanotechnology in cancer detection, diagnosis, and therapy have been widely reported. Engineering of vehicles for the simultaneous delivery of chemo- and radiotherapeutics increases the effectiveness of the therapy and reduces the dosage of each individual drug required to produce an observable therapeutic response. We here developed a novel chemoradiotherapeutic 1,2-dioleoyl-sn-glycero-3-phosphocholine lipid coated/uncoated platinum drug loaded, holmium-containing, wrinkled mesoporous silica nanoparticle. The materials were characterized with TEM, FTIR, 1H NMR, energy dispersive x-ray, inductively coupled plasma-mass spectrometry, and zeta potential measurements. In vitro platinum drug release from both lipid coated and uncoated chemoradiotherapeutic wrinkled mesoporous silica are reported. Various kinetic models were used to analyze the release kinetics. The radioactivity of the chemoradiotherapeutic nanocarriers was measured after neutron-activation.

  3. Mesoporous multilayer thin films: environment-sensitive photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Soler Illia, Galo; Fuertes, Maria Cecilia; Angelome, Paula Cecilia [Comision Nacional de Energia Atomica, San Martin, Buenos Aires (Argentina). Centro Atomico Constituyentes. Gerencia de Quimica; Marchi, Maria Claudia [Universidad de Buenos Aires (Argentina). Facultad de Ciencias Exactas y Naturales. INQUIMAE; Troiani, Horacio [Comision Nacional de Energia Atomica (CNEA), San Carlos de Bariloche (Argentina). Centro Atomico Bariloche and Instituto Balseiro; Luca, Vittorio [Australian Nuclear Science and Technology Organization, Lucas Heights (Australia). Inst. of Materials and Engineering Sciences; Miguez, Hernan [Consejo Superior de Investigaciones Cientificas, Isla de La Cartuja, Sevilla (Spain). Inst. de Ciencia de Materiales

    2008-11-15

    Photonic Crystals made up of stacked mesoporous thin films (MTF) were produced by sequential deposition. These materials present order at different length scales: atomic (local structure), mesoscopic (ordered mesopores) and submicronic (controlled thickness), which were accurately assessed by Small Angle X-ray Scattering (2D SAXS, D11A SAXS1) and X-ray Reflectometry (XRR, D10A XRD2). Each MTF building block of a complex multilayer architecture behaves like an 'optical switch' in the presence of vapours. Its electronic density (and therefore the refractive index) changes due to capillary condensation of a given solvent within the pore systems. This allows for the creation of photonic crystals that are responsive to environment, with promising applications in selective sensing or active waveguides. (author)

  4. In Situ Loading of Drugs into Mesoporous Silica SBA-15.

    Science.gov (United States)

    Wan, Mi Mi; Li, Yan Yan; Yang, Tian; Zhang, Tao; Sun, Xiao Dan; Zhu, Jian Hua

    2016-04-25

    In a new strategy for loading drugs into mesoporous silica, a hydrophilic (heparin) or hydrophobic drug (ibuprofen) is encapsulated directly in a one-pot synthesis by evaporation-induced self-assembly. In situ drug loading significantly cuts down the preparation time and dramatically increases the loaded amount and released fraction of the drug, and appropriate drug additives favor a mesoporous structure of the vessels. Drug loading was verified by FTIR spectroscopy and release tests, which revealed much longer release with a larger amount of heparin or ibuprofen compared to postloaded SBA-15. Besides, the in vitro anticoagulation properties of the released heparin and the biocompatibility of the vessels were carefully assessed, including activated partial thromboplastin time, thrombin time, hemolysis, platelet adhesion experiments, and the morphologies of red blood cells. A concept of new drug-release agents with soft core and hard shell is proposed and offers guidance for the design of novel drug-delivery systems.

  5. SAXS andalysis of interface in organo—modified mesoporous silica

    Institute of Scientific and Technical Information of China (English)

    ZhiHongLi; YanJunGong; DongWu; YuHanSun; JunWang; YiLiu; BaozhongDon

    2001-01-01

    A small-angle x-ray scattering(SAXS)technique using synchrotron radiation as the x-ray source has been employed to characterize the microstructure of mesoporous silica prepared by one-pot template-directed synthesis methodology.The scattering of pure silica agreed with Porod’s law.the scattering of organomodified mesoporous silica showed a negative deviation from Porod’s law,suggesting that an interfacial layer exists between the pores and silica matrix.It was the organic groups comprising the interface,as shown by 29Si cross-polarization magic-angle spinning nuclear magnetic resonance imaging (29Si cp MAS/NMR) and Fourier transform infrared spectroscopy(FTIR),that caused this negative deviation of SAXS intensity from Porod’s law,and the average thichness of the interfacial layer could be deduced from this negative deviation.Copyright 2001 john Wiley and Sons,Ltd.

  6. Mesoporous cobalt oxide for largely improved lithium storage properties

    Institute of Scientific and Technical Information of China (English)

    Mai Xia Ma

    2012-01-01

    We report the microstructure,application for lithium-ion batteries of mesoporous Co3O4 prepared by modified KIT-6 template method.The sample was characterized by XRD,TEM,HRTEM and nitrogen adsorption.Their electrochemical behaviors as electrode reactants for lithium ion batteries were evaluated by cyclic voltammograms and static charge-discharge.A direct comparison of electrochemical behaviors between mesoporous nanostructure and bulk reflects interesting "nanostructure effect",which is reasonably discussed in terms of how the 3D nanostructures of Co3O4 materials function in tuning their electrochemistry.The results demonstrate that further improvement of electrochemical performance in transition metal-oxide-based anode materials can be realized via the design of multiporous nanostructured materials.

  7. Template preparation of twisted nanoparticles of mesoporous silica

    Institute of Scientific and Technical Information of China (English)

    Kui Niu; Zhongbin Ni; Chengwu Fu; Tatsuo Kaneko; Mingqing Chen

    2011-01-01

    Optical isomers of N-lauroyl-L-(or-D-) alanine sodium salt {C12-L-(or-D-)AlaS} surfactants were used for the preparation of mesoporous silica nanoparticles with a twisted hexagonal rod-like morphology. Thermogravimetric analysis (TGA) was used to determine the temperature for template removal. Circular dichroism (CD) spectra of the surfactant solution with various compositions illustrated the formation and supramolecular assembly of protein-like molecular architecture leading to formation of twisted nanoparticles. Scanning electron microscopy (SEM),high-resolution transmission electron microscopy (HRTEM)and X-ray powder diffraction (XRD) patterns of these as-synthesized mesoporous silica confirmed that the twisted morphology of these nanoparticles was closely related to the supramolecular-assembled complex of amino acid surfactants.

  8. Interconnected mesopores and high accessibility in UVM-7-like silicas

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Cabero, Monica [Universitat de Valencia, Institut de Ciencia dels Materials (Spain); Hungria, Ana B. [Universidad de Cadiz, Departamento de Ciencia de Materiales, Ingenieria Metalurgica y Quimica Inorganica (Spain); Morales, Jose Manuel [Universitat de Valencia, Institut de Ciencia dels Materials (Spain); Tortajada, Marta; Ramon, Daniel [Biopolis S. L. (Spain); Moragues, Alaina; El Haskouri, Jamal; Beltran, Aurelio; Beltran, Daniel; Amoros, Pedro, E-mail: pedro.amoros@uv.es [Universitat de Valencia, Institut de Ciencia dels Materials (Spain)

    2012-08-15

    Nanoparticulated bimodal mesoporous silicas (NBS) have proved to constitute adequate supports in a variety of applications requiring enhanced accessibility to the active sites. Mass-transfer kinetics seems to be highly favoured in UVM-7-derived NBS materials. To understand the mass-diffusion phenomena throughout UVM-7-like supports requires well-grounded knowledge about their pore architecture. 3-D reconstructions of the UVM-7 mesostructure carried out by electron tomography reveal the existence of a true hierarchic connectivity involving both inter- and intra-nanoparticle pores. This connectivity makes self-supported nanoparticulated mesoporous bimodal carbon replicas of the supports feasible to obtaining by nanocasting. Both the temperature-induced mobility of gold nanodomains and the fast and efficient enzyme adsorption in UVM-7-like silicas are examples of non-constrained diffusion processes happening inside such an open network.

  9. Designing advanced functional periodic mesoporous organosilicas for biomedical applications

    Directory of Open Access Journals (Sweden)

    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.

  10. HIGH PROTON CONDUCTIVITY OF MESOPOROUS Al2O3

    Science.gov (United States)

    Shen, Hangyan; Maekawa, Hideki; Fujimaki, Yutaka; Kawada, Koutaro; Yamamura, Tsutomu

    Mesoporous Al2O3 was synthesized by the sol-gel method and the pore size was controlled over the range of 3-15nm. Proton conductivity of these samples was examined, which was as high as 0.004 S·cm-1 at 25°C. A systematic dependence of conductivity upon pore size was observed, in which the conductivity increased with increasing the pore size. Meanwhile the conductivity increased with increasing the humidity. Two peaks were observed in 1H NMR spectra, assigned to a "mobile" and an "immobile" proton, respectively. It can be seen that the conductivity of mesoporous-Al2O3 increased with increasing the "mobile" proton concentration. From TG-DTA measurement, proton species were categorized into three groups. It is suggested the group II protons have close relation with the NMR observed "mobile" protons.

  11. Chemoradiotherapeutic wrinkled mesoporous silica nanoparticles for use in cancer therapy

    Science.gov (United States)

    Munaweera, Imalka; Koneru, Bhuvaneswari; Shi, Yi; Di Pasqua, Anthony J.; Balkus, Kenneth J., Jr.

    2014-11-01

    Over the last decade, the development and application of nanotechnology in cancer detection, diagnosis, and therapy have been widely reported. Engineering of vehicles for the simultaneous delivery of chemo- and radiotherapeutics increases the effectiveness of the therapy and reduces the dosage of each individual drug required to produce an observable therapeutic response. We here developed a novel chemoradiotherapeutic 1,2-dioleoyl-sn-glycero-3-phosphocholine lipid coated/uncoated platinum drug loaded, holmium-containing, wrinkled mesoporous silica nanoparticle. The materials were characterized with TEM, FTIR, 1H NMR, energy dispersive x-ray, inductively coupled plasma-mass spectrometry, and zeta potential measurements. In vitro platinum drug release from both lipid coated and uncoated chemoradiotherapeutic wrinkled mesoporous silica are reported. Various kinetic models were used to analyze the release kinetics. The radioactivity of the chemoradiotherapeutic nanocarriers was measured after neutron-activation.

  12. Chemoradiotherapeutic wrinkled mesoporous silica nanoparticles for use in cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Munaweera, Imalka; Balkus, Kenneth J. Jr., E-mail: Balkus@utdallas.edu, E-mail: Anthony.DiPasqua@unthsc.edu [Department of Chemistry, University of Texas at Dallas, 800 West Campbell Rd., Richardson, Texas 75080 (United States); Koneru, Bhuvaneswari; Shi, Yi; Di Pasqua, Anthony J., E-mail: Balkus@utdallas.edu, E-mail: Anthony.DiPasqua@unthsc.edu [Department of Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, Texas 76107 (United States)

    2014-11-01

    Over the last decade, the development and application of nanotechnology in cancer detection, diagnosis, and therapy have been widely reported. Engineering of vehicles for the simultaneous delivery of chemo- and radiotherapeutics increases the effectiveness of the therapy and reduces the dosage of each individual drug required to produce an observable therapeutic response. We here developed a novel chemoradiotherapeutic 1,2-dioleoyl-sn-glycero-3-phosphocholine lipid coated/uncoated platinum drug loaded, holmium-containing, wrinkled mesoporous silica nanoparticle. The materials were characterized with TEM, FTIR, {sup 1}H NMR, energy dispersive x-ray, inductively coupled plasma-mass spectrometry, and zeta potential measurements. In vitro platinum drug release from both lipid coated and uncoated chemoradiotherapeutic wrinkled mesoporous silica are reported. Various kinetic models were used to analyze the release kinetics. The radioactivity of the chemoradiotherapeutic nanocarriers was measured after neutron-activation.

  13. Fluorescent Functionalized Mesoporous Silica for Radioactive Material Extraction

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-08-01

    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.

  14. Adsorption of benzene, cyclohexane and hexane on ordered mesoporous carbon.

    Science.gov (United States)

    Wang, Gang; Dou, Baojuan; Zhang, Zhongshen; Wang, Junhui; Liu, Haier; Hao, Zhengping

    2015-04-01

    Ordered mesoporous carbon (OMC) with high specific surface area and large pore volume was synthesized and tested for use as an adsorbent for volatile organic compound (VOC) disposal. Benzene, cyclohexane and hexane were selected as typical adsorbates due to their different molecular sizes and extensive utilization in industrial processes. In spite of their structural differences, high adsorption amounts were achieved for all three adsorbates, as the pore size of OMC is large enough for the access of these VOCs. In addition, the unusual bimodal-like pore size distribution gives the adsorbates a higher diffusion rate compared with conventional adsorbents such as activated carbon and carbon molecular sieve. Kinetic analysis suggests that the adsorption barriers mainly originated from the difficulty of VOC vapor molecules entering the pore channels of adsorbents. Therefore, its superior adsorption ability toward VOCs, together with a high diffusion rate, makes the ordered mesoporous carbon a promising potential adsorbent for VOC disposal.

  15. Tc-99 Ion Exchange Resin Testing

    Energy Technology Data Exchange (ETDEWEB)

    Valenta, Michelle M.; Parker, Kent E.; Pierce, Eric M.

    2010-08-01

    Pacific Northwest National Laboratory was contracted by CHPRC to evaluate the release of 99Tc from spent resin used to treat water from well 299-W15-765 and stored for several years. The key questions to be answered are: 1) does 99Tc readily release from the spent ion exchange resin after being in storage for several years; 2) if hot water stripping is used to remove the co-contaminant carbon tetrachloride, will 99Tc that has been sequestered by the resin be released; and 3) can spent resin be encapsulated into a cementitious waste form; if so, how much 99Tc would be released from the weathering of the monolith waste form? The results from the long term stability leach test results confirm that the resin is not releasing a significant amount of the sequestered 99Tc, evident by the less than 0.02% of the total 99Tc loaded being identified in the solution. Furthermore, it is possible that the measured 99Tc concentration is the result of 99Tc contained in the pore spaces of the resin. In addition to these results, analyses conducted to examine the impact of hot water on the release of 99Tc suggest that only a small percentage of the total is being released. This suggest that hot water stripping to remove carbon tetrachloride will not have a significant affect on the resin’s ability to hold-on to sequestered 99Tc. Finally, encapsulation of spent resin in a cementitious material may be a viable disposal option, but additional tests are needed to examine the extent of physical degradation caused by moisture loss and the effect this degradation process can have on the release of 99Tc.

  16. Morin Flavonoid Adsorbed on Mesoporous Silica, a Novel Antioxidant Nanomaterial

    OpenAIRE

    Arriagada, Francisco; Correa, Olosmira; Günther, Germán; Nonell, Santi; Mura, Francisco; Olea-Azar, Claudio; MORALES, JAVIER

    2016-01-01

    Morin (2´,3, 4´,5,7-pentahydroxyflavone) is a flavonoid with several beneficial health effects. However, its poor water solubility and it sensitivity to several environmental factors avoid its use in applications like pharmaceutical and cosmetic. In this work, we synthetized morin-modified mesoporous silica nanoparticles (AMSNPs-MOR) as useful material to be used as potential nanoantioxidant. To achieve this, we characterized its adsorption kinetics, isotherm and the antioxidant capacity as h...

  17. Direct hydrothermal synthesis of novel functional mesoporous materials

    Institute of Scientific and Technical Information of China (English)

    WU Zhengying; WEI Yilun; WANG Yimeng; ZHU Jianhua

    2004-01-01

    A direct synthesis method of preparing alkaline earth or transition metal oxides supporting mesoporous materials is reported. Distinguishing from those traditional techniques characterized by "synthesis at first and then modification", this new method adds the precursor salts that have no perturbation in the strong acid synthetic system but easily form oxides after calcinations, into the initial synthetic mixture, performing the "synthesis" and "modification" in one-pot procedure.

  18. Intrusion and extrusion of water in hydrophobic mesopores

    OpenAIRE

    Barrat, Jean-Louis; Lefevre, Benoit; Bocquet, Lyderic; Saugey, Anthony; Vigier, Gérard; Gobin, Pierre-François; Charlaix, Elisabeth

    2003-01-01

    We present experimental and theoretical results on intrusion-extrusion cycles of water in hydrophobic mesoporous materials, characterized by independent cylindrical pores. The intrusion, which takes place above the bulk saturation pressure, can be well described using a macroscopic capillary model. Once the material is saturated with water, extrusion takes place upon reduction of the externally applied pressure; Our results for the extrusion pressure can only be understood by assuming that th...

  19. Thermal cycling effects on adhesion of resin-bovine enamel junction among different composite resins.

    Science.gov (United States)

    Chen, Wen-Cheng; Ko, Chia-Ling; Wu, Hui-Yu; Lai, Pei-Ling; Shih, Chi-Jen

    2014-10-01

    Thermal cycling is used to mimic the changes in oral cavity temperature experienced by composite resins when used clinically. The purpose of this study is to assess the thermal cycling effects of in-house produced composite resin on bonding strength. The dicalcium phosphate anhydrous filler surfaces are modified using nanocrystals and silanization (w/NP/Si). The resin is compared with commercially available composite resins Filtek Z250, Z350, and glass ionomer restorative material GIC Fuji-II LC (control). Different composite resins were filled into the dental enamel of bovine teeth. The bond force and resin-enamel junction graphical structures of the samples were determined after thermal cycling between 5 and 55°C in deionized water for 600 cycles. After thermal cycling, the w/NP/Si 30wt%, 50wt% and Filtek Z250, Z350 groups showed higher shear forces than glass ionomer GIC, and w/NP/Si 50wt% had the highest shear force. Through SEM observations, more of the fillings with w/NP/Si 30wt% and w/NP/Si 50wt% groups flowed into the enamel tubule, forming closed tubules with the composite resins. The push-out force is proportional to the resin flow depth and uniformity. The push-out tubule pore and resin shear pattern is the most uniform and consistent in the w/NP/Si 50wt% group. Accordingly, this developed composite resin maintains great mechanical properties after thermal cycling. Thus, it has the potential to be used in a clinical setting when restoring non-carious cervical lesions.

  20. Rapid removal of bisphenol A on highly ordered mesoporous carbon

    Institute of Scientific and Technical Information of China (English)

    Qian Sui; Jun Huang; Yousong Liu; Xiaofeng Chang; Guangbin Ji; Shubo Deng; Tao Xie; Gang Yu

    2011-01-01

    Bisphenol A (BPA) is of global concern due to its disruption of endocrine systems and ubiquity in the aquatic environment. It is important, therefore, that efforts are made to remove it from the aqueous phase. A novel adsorbent, mesoporous carbon CMK-3,prepared from hexagonal SBA-15 mesoporous silica was studied for BPA removal from aqueous phase, and compared with conventional powdered activated carbon (PAC). Characterization of CMK-3 by transmission electron microscopy (TEM), X-ray diffraction, and nitrogen adsorption indicated that prepared CMK-3 had an ordered mesoporous structure with a high specific surface area of 920 m2/g and a pore-size of about 4.9 nm. The adsorption of BPA on CMK-3 followed a pseudo second-order kinetic model. The kinetic constant was 0.00049 g/(mg·min), much higher than the adsorption of BPA on PAC. The adsorption isotherm fitted slightly better with the Freundlich model than the Langmuir model, and adsorption capacity decreased as temperature increased from 10 to 40℃.No significant influence of pH on adsorption was observed at pH 3 to 9; however, adsorption capacity decreased dramatically from pH 9to 13.

  1. Capacity of mesoporous bioactive glass nanoparticles to deliver therapeutic molecules

    Science.gov (United States)

    El-Fiqi, Ahmed; Kim, Tae-Hyun; Kim, Meeju; Eltohamy, Mohamed; Won, Jong-Eun; Lee, Eun-Jung; Kim, Hae-Won

    2012-11-01

    Inorganic bioactive nanomaterials are attractive for hard tissue regeneration, including nanocomponents for bone replacement composites and nanovehicles for delivering therapeutics. Bioactive glass nanoparticles (BGn) have recently gained potential usefulness as bone and tooth regeneratives. Here we demonstrate the capacity of the BGn with mesopores to load and deliver therapeutic molecules (drugs and particularly genes). Spherical BGn with sizes of 80-90 nm were produced to obtain 3-5 nm sized mesopores through a sono-reacted sol-gel process. A simulated body fluid test of the mesoporous BGn confirmed their excellent apatite forming ability and the cellular toxicity study demonstrated their good cell viability up to 100 μg ml-1. Small molecules like chemical drug (Na-ampicillin) and gene (small interfering RNA; siRNA) were introduced as model drugs considering the mesopore size of the nanoparticles. Moreover, amine-functionalization allowed switchable surface charge property of the BGn (from -20-30 mV to +20-30 mV). Loading of ampicillin or siRNA saturated within a few hours (~2 h) and reflected the mesopore structure. While the ampicillin released relatively rapidly (~12 h), the siRNA continued to release up to 3 days with almost zero-order kinetics. The siRNA-nanoparticles were easily taken up by the cells, with a transfection efficiency as high as ~80%. The silencing effect of siRNA delivered from the BGn, as examined by using bcl-2 model gene, showed dramatic down-regulation (~15% of control), suggesting the potential use of BGn as a new class of nanovehicles for genes. This, in conjunction with other attractive properties, including size- and mesopore-related high surface area and pore volume, tunable surface chemistry, apatite-forming ability, good cell viability and the possible ion-related stimulatory effects, will potentiate the usefulness of the BGn in hard tissue regeneration.Inorganic bioactive nanomaterials are attractive for hard tissue regeneration

  2. Benzylation of Toluene over Iron Modified Mesoporous Ceria

    Directory of Open Access Journals (Sweden)

    K.J. Rose Philo

    2012-12-01

    Full Text Available Green chemistry has been looked upon as a sustainable science which accomplishes both economical and environmental goals, simultaneously.With this objective, we developed an alternative process to obtain the industrially important benzyl aromatics by benzylation of aromatics using benzyl chloride, catalysed by mesoporous solid acid catalysts. In this work mesoporous ceria is prepared using neutral surfactant which helped the calcination possible at a lower temperature enabling a higher surface area. Mesoporous ceria modified with Fe can be successfully utilized for the selective benzylation of toluene to more desirable product methyl diphenyl methane with 100% conversion and selectivity in 2 hours using only 50mg of the catalyst under milder condition. The reusability, regenerability, high selectivity, 100% conversion, moderate reaction temperature and absence of solvent, etc. make these catalysts to be used in a truly heterogeneous manner and make the benzylation reaction an environment friendly one. Copyright © 2012 by BCREC UNDIP. All rights reservedReceived: 30th June 2012; Revised: 7th November 2012; Accepted: 10th November 2012[How to Cite: K.J. Rose Philo, S. Sugunan. (2012. Benzylation of Toluene over Iron Modified Mesoporouxs Ceria. Bulletin of Chemical Reaction Engineering & Catalysis, 7(2: 158-164. (doi:10.9767/bcrec.7.2.3759.158-164][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.2.3759.158-164 ] | View in 

  3. Nucleation Pathways of CO2 Condensation under Mesoporous Templated Glass

    Science.gov (United States)

    Wang, Bo; Byran, Matthew S.; Warren, Garfield T.; Sokol, Paul E.; Indiana University Team; NIST Collaboration

    2015-03-01

    Carbon capture and storage (CCS) are important elements in reducing greenhouse gas emission and combating global warming. The adsorption behavior of CO2 under mesoporous confinement at room temperature is particularly relevant. , Small Angle Scattering of X-ray (SAXS) and Neutron (SANS) were used to probe the adsorption process of CO2 under such mesoporous confinement MCM-41 and details of nucleation pathways were mapped out by fitting the scattering intensities with adsorption models. From both experiments, the nucleation of CO2 on the inner pore surface of MCM-41 is found to be a two-step process; high density liquid phase CO2 first forms uniform layers following the long range translational symmetry of the porous matrix, above one CO2 filling, determined by the pore size and temperature, capillary condensation initiates. The nucleation sites formed during capillary condensation start to separate the long range symmetry from the one at uniform layers. Finally, SAXS and SANS techniques are compared and they both showed their unique properties of probing the filling-dependent structures of adsorbed CO2 under such mesoporous system.

  4. Carbon dioxide capture using polyethylenimine-loaded mesoporous carbons

    Institute of Scientific and Technical Information of China (English)

    Jitong Wang; Huichao Chen; Huanhuan Zhou; Xiaojun Liu; Wenming Qiao; Donghui Long; Licheng Ling

    2013-01-01

    A high efficiency sorbent for CO2 capture was developed by loading polyethylenimine (PEI) on mesoporous carbons which possessed well-developed mesoporous structures and large pore volume.The physicochemical properties of the sorbent were characterized by N2 adsorption/desorption,scanning electron microscopy (SEM),thermal gravimetric analysis (TG) and Fourier transform infrared spectroscopy (FT-IR) techniques followed by testing for CO2 capture.Factors that affected the sorption capacity of the sorbent were studied.The sorbent exhibited extraordinary capture capacity with CO2 concentration ranging from 5% to 80%.The optimal PEI loading was determined to be 65 wt.% with a CO2 sorption capacity of 4.82 mmol-CO2/g-sorbent in 15% CO2/N2 at 75℃,owing to low mass-transfer resistance and a high utilization ratio of the amine compound (63%).Moisture had a promoting effect on the sorption separation of CO2.In addition,the developed sorbent could be regenerated easily at 100℃,and it exhibited excellent regenerability and stability.These results indicate that this PEI-loaded mesoporous carbon sorbent should have a good potential for CO2 capture in the future.

  5. Carbon dioxide capture using polyethylenimine-loaded mesoporous carbons.

    Science.gov (United States)

    Wang, Jitong; Chen, Huichao; Zhou, Huanhuan; Liu, Xiaojun; Qiao, Wenming; Long, Donghui; Ling, Licheng

    2013-01-01

    A high efficiency sorbent for CO2 capture was developed by loading polyethylenimine (PEI) on mesoporous carbons which possessed well-developed mesoporous structures and large pore volume. The physicochemical properties of the sorbent were characterized by N2 adsorption/desorption, scanning electron microscopy (SEM), thermal gravimetric analysis (TG) and Fourier transform infrared spectroscopy (FT-IR) techniques followed by testing for CO2 capture. Factors that affected the sorption capacity of the sorbent were studied. The sorbent exhibited extraordinary capture capacity with CO2 concentration ranging from 5% to 80%. The optimal PEI loading was determined to be 65 wt.% with a CO2 sorption capacity of 4.82 mmol-CO2/g-sorbent in 15% CO2/N2 at 75 degrees C, owing to low mass-transfer resistance and a high utilization ratio of the amine compound (63%). Moisture had a promoting effect on the sorption separation of CO2. In addition, the developed sorbent could be regenerated easily at 100 degrees C, and it exhibited excellent regenerability and stability. These results indicate that this PEI-loaded mesoporous carbon sorbent should have a good potential for CO2 capture in the future.

  6. Functionalized mesoporous silica nanoparticles for oral delivery of budesonide

    Energy Technology Data Exchange (ETDEWEB)

    Yoncheva, K., E-mail: krassi.yoncheva@gmail.com [Department of Pharmaceutical Technology, Faculty of Pharmacy, Medical University of Sofia, 2 Dunav Str., 1000 Sofia (Bulgaria); Popova, M. [Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia (Bulgaria); Szegedi, A.; Mihaly, J. [Institute of Nanochemistry and Catalysis, Chemical Research Center, Hungarian Academy of Sciences, Pusztaszeri út. 59-67, 1025 Budapest (Hungary); Tzankov, B.; Lambov, N.; Konstantinov, S.; Tzankova, V. [Department of Pharmaceutical Technology, Faculty of Pharmacy, Medical University of Sofia, 2 Dunav Str., 1000 Sofia (Bulgaria); Pessina, F.; Valoti, M. [Dipartimento di Scienze della Vita, Universita di Siena, via Aldo Moro 2, Siena (Italy)

    2014-03-15

    Non-functionalized and amino-functionalized mesoporous silica nanoparticle were loaded with anti-inflammatory drug budesonide and additionally post-coated with bioadhesive polymer (carbopol). TEM images showed spherical shape of the nanoparticles and slightly higher polydispersity after coating with carbopol. Nitrogen physisorption and thermogravimetic analysis revealed that more efficient loading and incorporation into the pores of nanoparticles was achieved with the amino-functionalized silica carrier. Infrared spectra indicated that the post-coating of these nanoparticles with carbopol led to the formation of bond between amino groups of the functionalized carrier and carboxyl groups of carbopol. The combination of amino-functionalization of the carrier with the post-coating of the nanoparticles sustained budesonide release. Further, an in vitro model of inflammatory bowel disease showed that the cytoprotective effect of budesonide loaded in the post-coated silica nanoparticles on damaged HT-29 cells was more pronounced compared to the cytoprotection obtained with pure budesonide. -- Graphical abstract: Silica mesoporous MCM-41 particles were amino-functionalized, loaded with budesonide and post-coated with bioadhesive polymer (carbopol) in order to achieve prolonged residence of anti-inflammatory drug in GIT. Highlights: • Higher drug loading in amino-functionalized mesoporous silica. • Amino-functionalization and post-coating of the nanoparticles sustained drug release. • Achievement of higher cytoprotective effect with drug loaded into the nanoparticles.

  7. Mesoporous Metal-Containing Carbon Nitrides for Improved Photocatalytic Activities

    Directory of Open Access Journals (Sweden)

    Jie Luo

    2013-01-01

    Full Text Available Graphitic carbon nitrides (g-C3N4 have attracted increasing interest due to their unusual properties and promising applications in water splitting, heterogeneous catalysis, and organic contaminant degradation. In this study, a new method was developed for the synthesis of mesoporous Fe contained g-C3N4 (m-Fe-C3N4 photocatalyst by using SiO2 nanoparticles as hard template and dicyandiamide as precursor. The physicochemical properties of m-Fe-C3N4 were thoroughly investigated. The XRD and XPS results indicated that Fe was strongly coordinated with the g-C3N4 matrix and that the doping and mesoporous structure partially deteriorated its crystalline structure. The UV-visible absorption spectra revealed that m-Fe-C3N4 with a unique electronic structure displays an increased band gap in combination with a slightly reduced absorbance, implying that mesoporous structure modified the electronic properties of g-Fe-C3N4. The photocatalytic activity of m-Fe-C3N4 for photodegradation of Rhodamine B (RhB was much higher than that of g-Fe-C3N4, clearly demonstrating porous structure positive effect.

  8. Sustained release of fungicide metalaxyl by mesoporous silica nanospheres

    Energy Technology Data Exchange (ETDEWEB)

    Wanyika, Harrison, E-mail: hwanyika@gmail.com [Jomo Kenyatta University of Agriculture and Technology, Department of Chemistry (Kenya)

    2013-08-15

    The use of nanomaterials for the controlled delivery of pesticides is nascent technology that has the potential to increase the efficiency of food production and decrease pollution. In this work, the prospect of mesoporous silica nanoparticles (MSN) for storage and controlled release of metalaxyl fungicide has been investigated. Mesoporous silica nanospheres with average particle diameters of 162 nm and average pore sizes of 3.2 nm were prepared by a sol-gel process. Metalaxyl molecules were loaded into MSN pores from an aqueous solution by a rotary evaporation method. The loaded amount of metalaxyl as evaluated by thermogravimetric analysis was about 14 wt%. Release of the fungicide entrapped in the MSN matrix revealed sustained release behavior. About 76 % of the free metalaxyl was released in soil within a period of 30 days while only 11.5 and 47 % of the metalaxyl contained in the MSN carrier was released in soil and water, respectively, within the same period. The study showed that MSN can be used to successfully store metalaxyl molecules in its mesoporous framework and significantly delay their release in soil.

  9. Immobilization of mesoporous silica particles on stainless steel plates

    Science.gov (United States)

    Pasqua, Luigi; Morra, Marco

    2017-03-01

    A preliminary study aimed to the nano-engineering of stainless steel surface is presented. Aminopropyl-functionalized mesoporous silica is covalently and electrostatically anchored on the surface of stainless steel plates. The anchoring is carried out through the use of a nanometric spacer, and two different spacers are proposed (both below 2 nm in size). The first sample is obtained by anchoring to the stainless steel amino functionalized, a glutaryl dichloride spacer. This specie forms an amide linkage with the amino group while the unreacted acyl groups undergo hydrolysis giving a free carboxylic group. The so-obtained functionalized stainless steel plate is used as substrate for anchoring derivatized mesoporous silica particles. The second sample is prepared using 2-bromo-methyl propionic acid as spacer (BMPA). Successively, the carboxylic group of propionic acid is condensed to the aminopropyl derivatization on the external surface of the mesoporous silica particle through covalent bond. In both cases, a continuous deposition (coating thickness is around 10 μm) is obtained, in fact, XPS data do not reveal the metal elements constituting the plate. The nano-engineering of metal surfaces can represent an intriguing opportunity for producing long-term drug release or biomimetic surface.

  10. Adsorption behavior of natural anthocyanin dye on mesoporous silica

    Science.gov (United States)

    Kohno, Yoshiumi; Haga, Eriko; Yoda, Keiko; Shibata, Masashi; Fukuhara, Choji; Tomita, Yasumasa; Maeda, Yasuhisa; Kobayashi, Kenkichiro

    2014-01-01

    Because of its non-toxicity, naturally occurring anthocyanin is potentially suitable as a colorant for foods and cosmetics. To the wider use of the anthocyanin, the immobilization on the inorganic host for an easy handling as well as the improvement of the stability is required. This study is focused on the adsorption of significant amount of the natural anthocyanin dye onto mesoporous silica, and on the stability enhancement of the anthocyanin by the complexation. The anthocyanin has successfully been adsorbed on the HMS type mesoporous silica containing small amount of aluminum. The amount of the adsorbed anthocyanin has been increased by modifying the pore wall with n-propyl group to make the silica surface hydrophobic. The light fastness of the adsorbed anthocyanin has been improved by making the composite with the HMS samples containing aluminum, although the degree of the improvement is not so large. It has been proposed that incorporation of the anthocyanin molecule deep inside the mesopore is required for the further enhancement of the stability.

  11. Ordered mesoporous carbon for electrochemical sensing: A review

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. N-doped mesoporous alumina for adsorption of carbon dioxide

    Institute of Scientific and Technical Information of China (English)

    Jayshri A.Thote; Ravikrishna V.Chatti; Kartik S.Iyer; Vivek Kumar; Arti N.Valechha; Nitin K.Labhsetwar; Rajesh B.Biniwale; M.K.N.Yenkie; Sadhana S.Rayalu

    2012-01-01

    N-doped mesoporous alumina has been synthesized using chitosan as the biopolymer template.The adsorbent has been thoroughly investigated for the adsorption of CO2 from a simulated flue gas stream (15% CO2 balanced with N2) and compared with commercially available mesoporous alumina procured from SASOL,Germany.CO2 adsorption was studied under different conditions of pretreatment and adsorption temperature,inlet CO2 concentration and in the presence of oxygen and moisture.The adsorption capacity was determined to be 29.4 mg CO2/g of adsorbent at 55℃.This value was observed to be 4 times higher in comparison to that of commercial mesoporous alumina at a temperature of 55℃.Basicity of alumina surface coupled with the presence of nitrogen in template in synthesized sample is responsible for this enhanced CO2 adsorption.Adsorption capacity for CO2 was retained in the presence of oxygen; however moisture had a deteriorating effect on the adsorption capacity reducing it to nearly half the value.

  13. Clinical evaluation of a flowable resin composite and flowable compomer for preventive resin restorations.

    Science.gov (United States)

    Qin, Man; Liu, HongSheng

    2005-01-01

    This clinical study evaluated the retention and caries protection of a flowable resin composite (Flow Line) and a flowable compomer (Dyract Flow) used in preventive resin restorations as compared to the conventional preventive resin technique which uses a resin composite (Brilliant) and a sealant (Concise). This study observed 205 permanent molars with small carious cavities less than 1.5 mm in width, which were obtained from 165 children aged 7 to 15 years. Flowable resin composite was used to treat 75 teeth, and 71 teeth were treated with flowable compomer in both cavities and caries-free fissures. For the control group, 59 teeth were treated with resin composite in cavities and sealant in caries-free fissures. The teeth were evaluated at 3, 6, 12, 18 and 24-month intervals. After three months, all 205 treated teeth were completely intact. After six months, 66 of the 71 teeth treated with flowable resin composite and 65 of the 70 teeth treated with flowable compomer were complete, compared to 57 of the 58 teeth treated with the conventional preventive resin technique. After 12 months, 60 of the 67 teeth treated with flowable resin composite and 61 of the 67 teeth treated with flowable compomer were complete, compared to 51 of the 55 teeth treated with the conventional preventive resin technique. After 18 months, 53 of the 61 teeth treated with flowable resin composite and 54 of the 62 teeth treated with flowable compomer were complete, compared to 47 of the 53 teeth treated with the conventional preventive resin technique. After 24 months, 49 of the 58 teeth treated with flowable resin composite and 45 of the 57 teeth treated with flowable compomer were complete, compared to 42 of the 52 teeth treated with the conventional preventive resin technique. There were no statistically significant differences in retention rates among all groups after 3, 6, 12, 18 or 24-months (p>0.05). One tooth treated with flowable resin composite and one tooth treated with flowable

  14. Ponderosa pine resin defenses and growth: metrics matter.

    Science.gov (United States)

    Hood, Sharon; Sala, Anna

    2015-11-01

    Bark beetles (Coleoptera: Curculionidae, Scolytinae) cause widespread tree mortality in coniferous forests worldwide. Constitutive and induced host defenses are important factors in an individual tree's ability to survive an attack and in bottom-up regulation of bark beetle population dynamics, yet quantifying defense levels is often difficult. For example, in Pinus spp., resin flow is important for resistance to bark beetles but is extremely variable among individuals and within a season. While resin is produced and stored in resin ducts, the specific resin duct metrics that best correlate with resin flow remain unclear. The ability and timing of some pine species to produce induced resin is also not well understood. We investigated (i) the relationships between ponderosa pine (Pinus ponderosa Lawson & C. Lawson) resin flow and axial resin duct characteristics, tree growth and physiological variables, and (ii) if mechanical wounding induces ponderosa pine resin flow and resin ducts in the absence of bark beetles. Resin flow increased later in the growing season under moderate water stress and was highest in faster growing trees. The best predictors of resin flow were nonstandardized measures of resin ducts, resin duct size and total resin duct area, both of which increased with tree growth. However, while faster growing trees tended to produce more resin, models of resin flow using only tree growth were not statistically significant. Further, the standardized measures of resin ducts, density and duct area relative to xylem area, decreased with tree growth rate, indicating that slower growing trees invested more in resin duct defenses per unit area of radial growth, despite a tendency to produce less resin overall. We also found that mechanical wounding induced ponderosa pine defenses, but this response was slow. Resin flow increased after 28 days, and resin duct production did not increase until the following year. These slow induced responses may allow

  15. Biocompatibility of polymethylmethacrylate resins used in dentistry.

    Science.gov (United States)

    Gautam, Rupali; Singh, Raghuwar D; Sharma, Vinod P; Siddhartha, Ramashanker; Chand, Pooran; Kumar, Rakesh

    2012-07-01

    Biocompatibility or tissue compatibility describes the ability of a material to perform with an appropriate host response when applied as intended. Poly-methylmethacrylate (PMMA) based resins are most widely used resins in dentistry, especially in fabrication of dentures and orthodontic appliances. They are considered cytotoxic on account of leaching of various potential toxic substances, most common being residual monomer. Various in vitro and in vivo experiments and cell based studies conducted on acrylic based resins or their leached components have shown them to have cytotoxic effects. They can cause mucosal irritation and tissue sensitization. These studies are not only important to evaluate the long term clinical effect of these materials, but also help in further development of alternate resins. This article reviews information from scientific full articles, reviews, or abstracts published in dental literature, associated with biocompatibility of PMMA resins and it is leached out components. Published materials were searched in dental literature using general and specialist databases, like the PubMED database.

  16. Adsorption of L-phenylalanine onto mesoporous silica

    Energy Technology Data Exchange (ETDEWEB)

    Goscianska, Joanna; Olejnik, Anna; Pietrzak, Robert, E-mail: pietrob@amu.edu.pl

    2013-11-01

    Mesoporous silica materials, such as SBA-3, SBA-15, SBA-16 and KIT-6 were synthesized using tetraethyl orthosilicate as the silica source and different surfactants as templates. The products were characterised by a number of techniques, including low-temperature nitrogen sorption, X-ray diffraction and transmission electron microscopy. Results of the studies confirmed the ordered mesoporous structures of all silica samples obtained. Adsorption of L-phenylalanine on various mesoporous adsorbents was studied from solutions with different pH (5.6–9.4). Maximum sorption capacity was observed at pH 5.6, which is close to the isoelectric point of L-phenylalanine (pI = 5.48). Above this pH value, the amount of adsorbed amino acid decreased. In the range of equilibrium concentration (pH 5.6), the adsorption capacities of ordered silica samples decreased in the following order: KIT-6 (420 μmol g{sup −1}) > SBA-15 (389 μmol g{sup −1}) > SBA-16 (357 μmol g{sup −1}) > SBA-3 (219 μmol g{sup −1}). The lowest sorption capacity towards L-phenylalanine was found for SBA-3 despite the fact that it showed the largest surface area, which can be explained assuming that part of the pores in SBA-3 can be inaccessible to L-phenylalanine molecules. Large pore size of KIT-6 and SBA-15 permitted the amino acid molecule to enter into the pores of these mesoporous molecular sieves. - Highlights: • SBA-3, SBA-15, SBA-16, KIT-6 materials were prepared by hydrothermal method. • Ordered mesoporous silicas are promising as adsorbents of L-phenylalanine. • Adsorption of L-phenylalanine was studied from solutions with different pH. • Sorption capacities decrease in the following order: KIT-6 > SBA-15 > SBA-16 > SBA-3. • Large pore size of KIT-6 and SBA-15 permit the amino acid to enter into the pores.

  17. Structural Evaluation of High Strain Fiber and Resin Composite Material Systems

    Science.gov (United States)

    1986-04-01

    6 2. Resin Properties Necessary to Improve Laminate Properties ......................................... 6 3. Neat Resin Stress...Ratio, E/Eo OPSop 14Sl R Figure 2. Resin Properties Necessary to Improve Laminate Properties I 6 failure and normalized resin modulus. These...normalized resin-related parameters bound the resin properties which result in improvements in laminate transverse strength, transverse modulus, strain energy

  18. The influence of resin flexural modulus on the magnitude of ceramic strengthening.

    LENUS (Irish Health Repository)

    Fleming, Garry J P

    2012-07-01

    The aim was to determine the magnitude of ceramic resin-strengthening with resin-based materials with varying flexural moduli using a regression technique to assess the theoretical strengthening at a \\'zero\\' resin-coating thickness. The hypothesis tested was that experimentally, increasing resin flexural modulus results in increased resin-strengthening observed at a theoretical \\'zero\\' resin-coating thickness.

  19. 40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.

    Science.gov (United States)

    2010-07-01

    ... thermosetting resins subcategory. 414.50 Section 414.50 Protection of Environment ENVIRONMENTAL PROTECTION... Thermosetting Resins § 414.50 Applicability; description of the thermosetting resins subcategory. The provisions... the products classified under SIC 28214 thermosetting resins including those resins and resin...

  20. Vapor phase versus liquid phase grafting of meso-porous alumina

    NARCIS (Netherlands)

    Sripathi, V.G.P.; Mojet, B.L.; Nijmeijer, A.; Benes, N.E.

    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 significa

  1. Synthesis of Mesoporous Silica and Ti-containing Molecular Sieves via A Novel Assembly

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Thermally stable mesoporous silica and Ti-containing molecular sieves have been synthesized at mild temperature using low-cost and biodegradable---amphoteric tetradecyl betaine as template. The physicochemical characterizations proved that Ti(Ⅳ) could be incorporated in the mesoporous struture.

  2. Mesopore formation in zeolite H-SSZ-13 by desilication with NaOH

    NARCIS (Netherlands)

    Sommer, L.; Mores, D.; Svelle, S.; Stöcker, M; Weckhuysen, B.M.; Olsbye, U.

    2013-01-01

    A zeolite H-SSZ-13 material with CHA topology and a Si/Al ratio of 14 was treated with sodium hydroxide solutions of various concentrations. The post synthesis treatment led to desilication of the framework accompanied by mesopore formation. N2-physisorption measurements showed that the mesopore vol

  3. Spectroscopy of photonic band gaps in mesoporous one-dimensional photonic crystals based on aluminum oxide

    Science.gov (United States)

    Gorelik, V. S.; Voinov, Yu. P.; Shchavlev, V. V.; Bi, Dongxue; Shang, Guo Liang; Fei, Guang Tao

    2016-12-01

    Mesoporous one-dimensional photonic crystals based on aluminum oxide have been synthesized by electrochemical etching method. Reflection spectra of the obtained mesoporous samples in a wide spectral range that covers several band gaps are presented. Microscopic parameters of photonic crystals are calculated and corresponding reflection spectra for the first six band gaps are presented.

  4. Hydrothermal synthesis of mesoporous metal oxide arrays with enhanced properties for electrochemical energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Anguo, E-mail: hixiaoanguo@126.com; Zhou, Shibiao; Zuo, Chenggang; Zhuan, Yongbing; Ding, Xiang

    2015-01-15

    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{sup −1} at 2 A g{sup −1} and impressive high-rate capability with a specific capacitance of 338 F g{sup −1} at 40 A g{sup −1}. In addition, the mesoporous nanowall NiO arrays possess good cycling stability. After 6000 cycles at 2 A g{sup −1}, a high capacitance of 660 F g{sup −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.

  5. Studies on Supercapacitor Electrode Material from Activated Lignin-Derived Mesoporous Carbon

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Dipendu [ORNL; Li, Yunchao [ORNL; Bi, Zhonghe [ORNL; Chen, Jihua [ORNL; Keum, Jong Kahk [ORNL; Hensley, Dale K [ORNL; Grappe, Hippolyte A. [Oak Ridge Institute for Science and Education (ORISE); Meyer III, Harry M [ORNL; Dai, Sheng [ORNL; Paranthaman, Mariappan Parans [ORNL; Naskar, Amit K [ORNL

    2014-01-01

    We synthesized mesoporous carbon from pre-cross-linked lignin gel impregnated with a surfactant as the pore-forming agent, and then activated the carbon through physical and chemical methods to obtain activated mesoporous carbon. The activated mesoporous carbons exhibited 1.5- to 6-fold increases in porosity with a maximum BET specific surface area of 1148 m2/g and a pore volume of 1.0 cm3/g. Slow physical activation helped retain dominant mesoporosity; however, aggressive chemical activation caused some loss of the mesopore volume fraction. Plots of cyclic voltammetric data with the capacitor electrode made from these carbons showed an almost rectangular curve depicting the behavior of ideal double-layer capacitance. Although the pristine mesoporous carbon exhibited the same range of surface-area-based capacitance as that of other known carbon-based supercapacitors, activation decreased the surface-area-based specific capacitance and increased the gravimetric-specific capacitance of the mesoporous carbons. Surface activation lowered bulk density and electrical conductivity. Warburg impedance as a vertical tail in the lower frequency domain of Nyquist plots supported good supercapacitor behavior for the activated mesoporous carbons. Our work demonstrated that biomass-derived mesoporous carbon materials continue to show potential for use in specific electrochemical applications.

  6. Fluorinated Alkyl Ether Epoxy Resin Compositions and Applications Thereof

    Science.gov (United States)

    Wohl, Christopher J. (Inventor); Connell, John W. (Inventor); Smith, Joseph G. (Inventor); Siochi, Emilie J. (Inventor); Gardner, John M. (Inventor); Palmieri, Frank M. (Inventor)

    2017-01-01

    Epoxy resin compositions prepared using amino terminated fluoro alkyl ethers. The epoxy resin compositions exhibit low surface adhesion properties making them useful as coatings, paints, moldings, adhesives, and fiber reinforced composites.

  7. 76 FR 8774 - Granular Polytetrafluoroethylene Resin From Japan

    Science.gov (United States)

    2011-02-15

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Granular Polytetrafluoroethylene Resin From Japan AGENCY: United States International Trade... polytetrafluoroethylene resin from Japan would be likely to lead to continuation or recurrence of material injury....

  8. Composite resin fillings and inlays: An 11-year evaluation

    DEFF Research Database (Denmark)

    Pallesen, U.; Qvist, V.

    2003-01-01

    Clinical trial, composite resin, direct restorations, indirect restorations, long-term behaviour, posterior teeth......Clinical trial, composite resin, direct restorations, indirect restorations, long-term behaviour, posterior teeth...

  9. Development of Polymer Resins using Neural Networks

    Directory of Open Access Journals (Sweden)

    Fabiano A. N. Fernandes

    2002-01-01

    Full Text Available The development of polymer resins can benefit from the application of neural networks, using its great ability to correlate inputs and outputs. In this work we have developed a procedure that uses neural networks to correlate the end-user properties of a polymer with the polymerization reactor's operational condition that will produce that desired polymer. This procedure is aimed at speeding up the development of new resins and help finding the appropriate operational conditions to produce a given polymer resin; reducing experimentation, pilot plant tests and therefore time and money spent on development. The procedure shown in this paper can predict the reactor's operational condition with an error lower than 5%.

  10. Smooth coronal surface, resin restoration and microleakage.

    Science.gov (United States)

    Yanikoğlu, F; Türkmen, C; Kartal, N; Başaran, B

    1997-09-01

    The space between the resin and the cavity walls has always become interesting to search. The aim of this study was to evaluate any differences on leakage values of Class 5 type resin restorations prepared on surrounding surfaces of the tooth crown. Ninety human teeth were prepared as Class 5 cavities on buccal, lingual, mesial and distal surfaces and were randomly divided into groups for bevelling, groove preparation and as control. The subgroups were arranged as fluoride gel and/or sealant applications. Fluoride gel was applied following the cavity preparations. Sealant was applied over composite resin restorations. Treated teeth were thermocycled and immersed into dye solution for 96 hours. The restorations were evaluated in a stereo-microscope following the sectioning. Bevelling of the cavosurfaces and/or preparation of a groove addition to cavity procedures did not make any difference on the microleakage scores of the restorations done on either surfaces statistically.

  11. Composite resin in medicine and dentistry.

    Science.gov (United States)

    Stein, Pamela S; Sullivan, Jennifer; Haubenreich, James E; Osborne, Paul B

    2005-01-01

    Composite resin has been used for nearly 50 years as a restorative material in dentistry. Use of this material has recently increased as a result of consumer demands for esthetic restorations, coupled with the public's concern with mercury-containing dental amalgam. Composite is now used in over 95% of all anterior teeth direct restorations and in 50% of all posterior teeth direct restorations. Carbon fiber reinforced composites have been developed for use as dental implants. In medicine, fiber-reinforced composites have been used in orthopedics as implants, osseous screws, and bearing surfaces. In addition, hydroxyapatite composite resin has become a promising alternative to acrylic cement in stabilizing fractures and cancellous screw fixation in elderly and osteoporotic patients. The use of composite resin in dentistry and medicine will be the focus of this review, with particular attention paid to its physical properties, chemical composition, clinical applications, and biocompatibility.

  12. The Creep of Laminated Synthetic Resin Plastics

    Science.gov (United States)

    Perkuhn, H

    1941-01-01

    The long-time loading strength of a number of laminated synthetic resin plastics was ascertained and the effect of molding pressure and resin content determined. The best value was observed with a 30 to 40 percent resin content. The long-time loading strength also increases with increasing molding pressure up to 250 kg/cm(exp 2); a further rise in pressure affords no further substantial improvement. The creep strength is defined as the load which in the hundredth hour of loading produces a rate of elongation of 5 X 10(exp -4) percent per hour. The creep strength values of different materials were determined and tabulated. The effect of humidity during long-term tests is pointed out.

  13. Cycloaliphatic epoxy resin coating for capillary electrophoresis.

    Science.gov (United States)

    Shah, Roopa S; Wang, Qinggang; Lee, Milton L

    2002-04-05

    Coating the interior surface of a fused-silica capillary with a polymeric material has long been used in capillary electrophoresis (CE) to reduce or eliminate electroosmotic flow and suppress adsorption. A cycloaliphatic epoxide-based resin was bonded to silane treated capillaries and crosslinked with a curing agent. The epoxy resin coating significantly reduced electroosmotic flow over a pH range of 3-10. This coating was sufficiently hydrophilic to suppress protein adsorption. The epoxy resin coated capillary was used to separate several acidic and basic proteins and peptides. Separation efficiencies greater than 400,000 theoretical plates were achieved. The relative standard deviations in migration times for proteins were methods.

  14. Investigations of toughening mechanisms of epoxy resins

    Science.gov (United States)

    Koenig, T.

    1986-01-01

    Composite material technology was applied to the solid rocket booster by the development of a carbon filament-epoxy resin case which yields a net increase of 4000 lbs. in payload in the shuttle. The question of reusability of the new composite tanks has not yet been answered and will depend on the toughness of the matrix resin. The present study was aimed at providing conditions whereby test specimens of the epoxy resin (EPON/85) and curing agents of systematically varied structures could be produced in a controlled manner. Three sets of conditions were found that might allow the isolation of the structural effects on toughness from the cure effects. The kinetic methods leading to the determination of these conditions are described.

  15. [Allergic contact eczema from epoxy resin].

    Science.gov (United States)

    Calzado, Leticia; Ortiz-de Frutos, Francisco J; del Prado Sánchez-Caminero, María; Galera, Carmen María; Valverde, Ricardo; Vanaclocha, Francisco

    2005-11-01

    Epoxy resins are plastics that are widely used as electrical insulation, in coatings, and as adhesives and paints. They have strong sensitizing power and are one of the main causes of allergic contact eczema, both in the workplace and elsewhere. We present the case of a worker at a plastics/chemical plant, who handled aeronautical components in the process of manufacturing fuselage parts. He consulted his physician because of eczematous lesions on his fingers, hands and forearms which had developed over a two-year period and were clearly related to his work. The standard battery of skin tests was performed, along with the plastics and adhesives series and tests using the products from his workplace. Positivity was shown to epoxy resins (standard battery) and to the products from his workplace, which included different fiberglass and carbon fiber sheets impregnated with epoxy resins and epoxy adhesives.

  16. Resin injection in clays with high plasticity

    Science.gov (United States)

    Nowamooz, Hossein

    2016-11-01

    Regarding the injection process of polyurethane resins in clays with high plasticity, this paper presents the experimental results of the pressuremeter and cone penetration tests before and after injection. A very important increase in pressure limit or in soil resistance can be observed for all the studied depths close to the injection points. An analytical analysis for cylindrical pore cavity expansion in cohesive frictional soils obeying the Mohr-Coulomb criterion was then used to reproduce the pressuremeter tests before and after injection. The model parameters were calibrated by maintaining constant the elasticity parameters as well as the friction angel before and after injection. A significant increase in cohesion was observed because of soil densification after resin expansion. The estimated undrained cohesions, derived from the parameters of the Mohr-Coulomb criterion, were also compared with the cone penetration tests. Globally, the model predictions show the efficiency of resin injection in clay soils with high plasticity.

  17. Biphenyl liquid crystalline epoxy resin as a low-shrinkage resin-based dental restorative nanocomposite.

    Science.gov (United States)

    Hsu, Sheng-Hao; Chen, Rung-Shu; Chang, Yuan-Ling; Chen, Min-Huey; Cheng, Kuo-Chung; Su, Wei-Fang

    2012-11-01

    Low-shrinkage resin-based photocurable liquid crystalline epoxy nanocomposite has been investigated with regard to its application as a dental restoration material. The nanocomposite consists of an organic matrix and an inorganic reinforcing filler. The organic matrix is made of liquid crystalline biphenyl epoxy resin (BP), an epoxy resin consisting of cyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (ECH), the photoinitiator 4-octylphenyl phenyliodonium hexafluoroantimonate and the photosensitizer champhorquinone. The inorganic filler is silica nanoparticles (∼70-100 nm). The nanoparticles were modified by an epoxy silane of γ-glycidoxypropyltrimethoxysilane to be compatible with the organic matrix and to chemically bond with the organic matrix after photo curing. By incorporating the BP liquid crystalline (LC) epoxy resin into conventional ECH epoxy resin, the nanocomposite has improved hardness, flexural modulus, water absorption and coefficient of thermal expansion. Although the incorporation of silica filler may dilute the reinforcing effect of crystalline BP, a high silica filler content (∼42 vol.%) was found to increase the physical and chemical properties of the nanocomposite due to the formation of unique microstructures. The microstructure of nanoparticle embedded layers was observed in the nanocomposite using scanning and transmission electron microscopy. This unique microstructure indicates that the crystalline BP and nanoparticles support each other and result in outstanding mechanical properties. The crystalline BP in the LC epoxy resin-based nanocomposite was partially melted during exothermic photopolymerization, and the resin expanded via an order-to-disorder transition. Thus, the post-gelation shrinkage of the LC epoxy resin-based nanocomposite is greatly reduced, ∼50.6% less than in commercialized methacrylate resin-based composites. This LC epoxy nanocomposite demonstrates good physical and chemical properties and good biocompatibility

  18. Adsorption of D113 Resin for Dysprosium(Ⅲ)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The adsorption behavior and mechanism of D113 resin for Dy(Ⅲ) was investigated by using the method of resin adsorption. Experimental results show that the optimum medium pH of adsorption of D113 resin for Dy3+ is pH=6.00 in the HAc-NaAc medium. The static adsorption capacity of D113 resin for Dy3+chemical analysis and IR spectra.

  19. Improved Graphite Fiber/Acetylene Terminated Matrix Resin Prepreg Products

    Science.gov (United States)

    1988-03-01

    Neat Resin Properties Cured by Different Cure Cycles .............. 22 2.5 Effect of Cure Cycles on Water Absorption in m-ATS Neat Resins...Characterization of ATB Laminates ...... 81 3.4 Effect of Intermediate Temperature Hold on Neat Resin Properties for m-ATB Formulations ......... 86 3.5...using procedures described in Appendix A, are shown in Table 2.1. For comparison, the resin properties of a first generation epoxy, a state-of-the

  20. Preparative Purification of Liriodendrin from Sargentodoxa cuneata by Macroporous Resin

    OpenAIRE

    Di-Hua Li; Yan Wang; Yuan-Shan Lv; Jun-Hong Liu; Lei Yang; Shu-Kun Zhang; Yu-Zhen Zhuo

    2015-01-01

    The preparative purification of liriodendrin from Sargentodoxa cuneata using macroporous resin combined with crystallization process was evaluated. The properties of adsorption/desorption of liriodendrin on eight macroporous resins were investigated systematically. X-5 resin was selected as the most suitable medium for liriodendrin purification. The adsorption of liriodendrin on X-5 resin fitted well with the pseudo-second-order kinetic model and Langmuir isotherm model. Dynamic adsorption/de...

  1. Investigation of Resin Systems for Improved Ablative Materials

    Science.gov (United States)

    2010-02-25

    and synthe- sized in Task I. " Commercial Sources: Monsanto - Skybond 700 (polyimide), and Narmco - Polybenzimidazole. Optimization of the resins will...tested in Contract NAS3-4188 (DuPont SP-I and SP-2), a new polyimide resin produced by Monsanto (Skybond 700) has recently been added to those resins...laminates from the improved modified polyimides being synthesized in Task I. The new resin selected for evaluation was Monsanto Chemical Company’s Skybond 700

  2. Study on the Novel Dicyanate Ester Resin Containing Naphthalene Unit

    Institute of Scientific and Technical Information of China (English)

    Hong Qiang YAN; Hong Yun PENG; Li JI; Guo Rong QI

    2004-01-01

    The novel dicyanate ester resin containing naphthalene unit (DNCY) was synthesized, and characterized by FT-IR, 1H-NMR, 13C-NMR and elemental analysis (EA).The thermal properties of DNCY resin was studied by thermal degradation analysis at a heating rate of 10 (C /min-1 in N2 and air. The DNCY resin exhibited better thermal and thermal-oxidative stability than bisphenol A dicyanate (BACY) resin.

  3. Ordered mesoporous NiO with thin pore walls and its enhanced sensing performance for formaldehyde.

    Science.gov (United States)

    Lai, Xiaoyong; Shen, Guoxin; Xue, Ping; Yan, Bingqin; Wang, Hong; Li, Peng; Xia, Weitao; Fang, Junzhuo

    2015-03-07

    A class of formaldehyde (HCHO) gas sensors with a high response were developed based on ordered mesoporous NiO, which were synthesized via the nanocasting route by directly using mesoporous silica as the hard template. A series of mesoporous NiO with different textural parameters such as specific surface area, pore size, pore wall thickness were achieved by selecting mesoporous silica with different pore sizes as templates. The gas sensing properties for formaldehyde (HCHO) of the NiO specimens were examined. The results show that this mesoporous NiO possesses a much higher response to HCHO even at low concentration levels than the bulk NiO, and a larger specific surface area and pore size as well as thinner pore walls would be beneficial for enhancing the sensing properties of NiO.

  4. Mesoporous metal oxide microsphere electrode compositions and their methods of making

    Energy Technology Data Exchange (ETDEWEB)

    Paranthaman, Mariappan Parans; Liu, Hansan; Brown, Gilbert M.; Sun, Xiao-Guang; Bi, Zhonghe

    2016-12-06

    Compositions and methods of making are provided for mesoporous metal oxide microspheres electrodes. The mesoporous metal oxide microsphere compositions comprise (a) microspheres with an average diameter between 200 nanometers (nm) and 10 micrometers (.mu.m); (b) mesopores on the surface and interior of the microspheres, wherein the mesopores have an average diameter between 1 nm and 50 nm and the microspheres have a surface area between 50 m.sup.2/g and 500 m.sup.2/g. The methods of making comprise forming composite powders. The methods may also comprise refluxing the composite powders in a basic solution to form an etched powder, washing the etched powder with an acid to form a hydrated metal oxide, and heat-treating the hydrated metal oxide to form mesoporous metal oxide microspheres.

  5. Structure/Property Relationships of Poly(L-lactic Acid/Mesoporous Silica Nanocomposites

    Directory of Open Access Journals (Sweden)

    Javier Gudiño-Rivera

    2013-01-01

    Full Text Available Biodegradable poly(L-lactic acid (PLLA/mesoporous silica nanocomposites were prepared by grafting L-lactic acid oligomer onto silanol groups at the surface of mesoporous silica (SBA-15. The infrared results showed that the lactic acid oligomer was grafted onto the mesoporous silica. Surface characterization of mesoporous silica proved that the grafted oligomer blocked the entry of nitrogen into the mesopores. Thermal analysis measurements showed evidence that, once mixed with PLLA, SBA-15 not only nucleated the PLLA but also increased the total amount of crystallinity. Neat PLLA and its nanocomposites crystallized in the same crystal habit and, as expected, PLLA had a defined periodicity compared with the nanocomposites. This was because the grafted macromolecules on silica tended to cover the lamellar crystalline order. The g-SBA-15 nanoparticles improved the tensile moduli, increasing also the tensile strength of the resultant nanocomposites. Overall, the silica concentration tended to form a brittle material.

  6. Mesoporous zeolite single crystal catalysts: Diffusion and catalysis in hierarchical zeolites

    DEFF Research Database (Denmark)

    Christensen, Christina Hviid; Johannsen, Kim; Toernqvist, Eric

    2007-01-01

    During the last years, several new routes to produce zeolites with controlled mesoporosity have appeared. Moreover, an improved catalytic performance of the resulting mesoporous zeolites over conventional zeolites has been demonstrated in several reactions. In most cases, the mesoporous zeolites...... exhibit higher catalytic activity, but in some cases also improved selectivity and longer catalyst lifetime has been reported. The beneficial effects of introducing mesopores into the zeolites has in most instances been attributed to improved mass transport to and from the active sites located...... in the zeolite micropores. Here, we briefly discuss the most important ways of introducing mesopores into zeolites and, for the first time, we show experimentally that the presence of mesopores dramatically increases the rate of diffusion in zeolite catalysts. This is done by studying the elution of iso...

  7. Electrochromic and chemochromic performance of mesoporous thin-film vanadium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ping; Lee, Se-Hee; Tracy, C. Edwin; Turner, John A.; Pitts, J. Roland; Deb, Satyen K. [National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401 (United States)

    2003-12-01

    Mesoporous vanadium oxide thin films have been deposited electrochemically from a water/ethanol solution of vanadyl sulfate and a nonionic polymer surfactant. Aggregates of the polymer surfactant serve as templates that result in the formation of a mesoporous structure. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicate the presence of both macroporosity and mesoporosity in the electrodeposited film. Chemochromic behavior of mesoporous vanadium oxide is demonstrated in a palladium/vanadium oxide thin-film device, which colors when exposed to hydrogen gas. A comparison of results with evaporated vanadium oxide reveals that the mesoporous film displays an improved kinetic performance, which is most likely attributable to its highly porous structure. Also, the electrochemical properties have been explored in a lithium-battery configuration. Mesoporous vanadium oxide exhibits a very high lithium storage capacity and greatly enhanced charge-discharge rate. In situ optical measurements show that the film exhibits a multicolor electrochromic effect.

  8. Titanium-Containing Mesoporous Materials: Synthesis and Application in Selective Catalytic Oxidation

    Institute of Scientific and Technical Information of China (English)

    Jie Li; Chunhui Zhou; Huali Xie; Zhonghua Ge; Liangcai Yuan; Xiaonian Li

    2006-01-01

    Titanium-containing mesoporous molecular sieves are of great significance in selective catalytic oxidation processes with bulky molecules. Recent researches and developments on the designing and synthesis of Ti-containing mesoporous materials have been reviewed. Various strategies for the preparation of Ti-containing mesoporous materials, such as direct synthesis and post-synthesis, are described. Modifications of Ti-containing mesoporous materials by surface-grafting and atom-planting are also discussed. All approaches aimed mainly at the improving of the stability, the hydrophobicity, and mostly the catalytic activity. Structural and mechanistic features of various synthetic systems are discussed. Ticontaining mesoporous materials in liquid phase catalytic oxidation of organic compounds with H2O2 as an oxidant is briefly summarized, showing their broad utilities for green synthesis of fine chemicals by catalytic oxidative reactions.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  10. Synthesis of mesoporous carbon as electrode material for supercapacitor by modified template method

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jia-chang; LAI Chun-yan; DAI Yang; XIE Jing-ying

    2005-01-01

    The pore structures and electrochemical performances of mesoporous carbons prepared by silica sol template method as electrode material for supercapacitor were investigated. The mean pore size and mass specific capacitance of the mesoporous carbons increase with the increase of mass ratio of silica sol to carbon source (glucose). A modified template method, combining silica sol template method and ZnCl2 chemical activation method, was proposed to improve the mass specific capacitance of the mesoporous carbon with an improved BET surface area. The correlation of rate capability and pore structure was studied by constant current discharge and electrochemical impedance spectroscopy. A commercially available microporous carbon was used for comparison. The result shows that mesoporous carbon with a larger pore size displays a higher rate capability. Mesoporous carbon synthesized by modified template method has both high mass specific capacitance and good rate capability.

  11. Micro-mesoporous materials obtained by zeolite recrystallization: synthesis, characterization and catalytic applications.

    Science.gov (United States)

    Ivanova, Irina I; Knyazeva, Elena E

    2013-05-07

    The review covers the recent developments in the field of novel micro-mesoporous materials obtained by zeolite recrystallization. The materials are classified into three distinctly different groups depending on the degree of recrystallization: (i) coated mesoporous zeolites (RZEO-1); (ii) micro-mesoporous nanocomposites (RZEO-2); and (iii) mesoporous materials with zeolitic fragments in the walls (RZEO-3). The first part of the review is focused on the analysis of the synthetic strategies leading to different types of recrystallized materials. In the second part, a comprehensive view on their structure, texture and porosity in connection with acidic and diffusion properties is given. The last part is devoted to the catalytic applications of recrystallized materials. The advantages and disadvantages with respect to pure micro- and mesoporous molecular sieves and other hierarchical zeolites are critically analyzed and the future opportunities and perspectives are discussed.

  12. Structrue and Characteristics of Mesoporous Silica Synthesized in Acid Medium and Its Reaction Mechanism

    Institute of Scientific and Technical Information of China (English)

    LEI Jia-heng; ZHAO Jun; CHEN Yong-xi; GUO Li-ping; LIU Dan

    2004-01-01

    Structrue and pore characteristics of the mesoporous silica synthesized in acid medium were studied by means of XRD, HRTEM, BET, FT-IR, DSC-TGA, and the reaction mechanism was also investigated deeply. The results show that mesopores in the sample possess hexagonal arrays obviously, whereas the structure of silica matrix is amorphous. The results also show that the acting mode of silica and CTMA+ inside the mesopores was chemical bonding force. The structure of mesoporous silica was mainly dependent on the aggregational condition of micelle of CTMA+ as well as their liquid-crystallized status. In addition, condensation and dehydration of silicate radicals were accompanied in the process of calcination, which resulted in the mesoporous structure ordered in local range and the pore sizes largening.

  13. Benzonorbornadiene end caps for PMR resins

    Science.gov (United States)

    Panigot, Michael J.; Waters, John F.; Varde, Uday; Sutter, James K.; Sukenik, Chaim N.

    1992-01-01

    Several ortho-disubstituted benzonorbornadiene derivatives are described. These molecules contain acid, ester, or anhydride functionality permitting their use as end caps in PMR (polymerization of monomer reactants) polyimide systems. The replacement of the currently used norbornenyl end caps with benzonorbornadienyl end caps affords resins of increased aromatic content. It also allows evaluation of some mechanistic aspects of PMR cross-linking. Initial testing of N-phenylimide model compounds and of actual resin formulations using the benzonorbornadienyl end cap reveals that they undergo efficient thermal crosslinking to give oligomers with physical properties and thermal stability comparable to commercial norbornene-end-capped PMR systems.

  14. PMR Resin Compositions For High Temperatures

    Science.gov (United States)

    Vannucci, Raymond D.

    1989-01-01

    Report describes experiments to identify polymer matrix resins suitable for making graphite-fiber laminates used at 700 degree F (371 degree C) in such applications as aircraft engines to achieve higher thrust-to-weight ratios. Two particular high-molecular-weight formulations of PMR (polymerization of monomer reactants) resins most promising. PMR compositions of higher FMW exhibit enhanced thermo-oxidative stability. Formation of high-quality laminates with these compositions requires use of curing pressures higher than those suitable for compositions of lower FMW.

  15. Clinical guidelines for indirect resin restorations.

    Science.gov (United States)

    Shannon, A

    1997-06-01

    Ongoing advances in adhesive dentistry have made it possible to successfully and predictably bond tooth-supporting restorations using conservative preparation techniques. Improvements in the durability and esthetic properties of tooth-colored restorative materials have also increased the range of available treatment options. However, dentists have been slow to accept both direct and indirect posterior esthetics. This article provides a step-by-step technique for practitioners who choose to treat their patients with indirect resin esthetic restorations. It will not discuss other posterior restorative treatment techniques or materials (i.e. gold, porcelain, amalgam, bonded amalgam, or direct resin).

  16. Advances in the history of composite resins.

    Science.gov (United States)

    Minguez, Nieves; Ellacuria, Joseba; Soler, José Ignacio; Triana, Rodrigo; Ibaseta, Guillermo

    2003-11-01

    The use of composite resins as direct restoration material in posterior teeth has demonstrated a great increase, due to esthetic requirements and the controversy regarding the mercury content in silver amalgams. In this article, we have reviewed the composition modifications which have occurred in materials based on resins since their introduction over a half a century ago which have enabled great improvements in their physical and mechanical properties. Likewise, we have highlighted current lines of research, centered on finding the ideal material for replacing silver amalgam as a direct filling material.

  17. Solid-State Microwave Synthesis of Melamine-Formaldehyde Resin

    OpenAIRE

    Subhash Bajia; Rashmi Sharma; Birbal Bajia

    2009-01-01

    An efficient synthesis of melamine-formaldehyde resin has been achieved using conventional as well as microwave irradiations (without and with solid support) in different molar ratio. Resin samples were tested for their chemical as well as physical properties. The structure of all the resin has been supported by their spectral data

  18. 40 CFR 721.2752 - Epoxy resin containing phosphorus (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Epoxy resin containing phosphorus... Specific Chemical Substances § 721.2752 Epoxy resin containing phosphorus (generic). (a) Chemical substance... epoxy resin containing phosphorus (PMN P-00-912) is subject to reporting under this section for...

  19. 21 CFR 177.2355 - Mineral reinforced nylon resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Mineral reinforced nylon resins. 177.2355 Section... as Components of Articles Intended for Repeated Use § 177.2355 Mineral reinforced nylon resins. Mineral reinforced nylon resins identified in paragraph (a) of this section may be safely used as...

  20. Color change of composite resins subjected to accelerated artificial aging

    Directory of Open Access Journals (Sweden)

    Denise Cremonezzi Tornavoi

    2013-01-01

    Conclusions: All composite resins presented unacceptable color changes after 382 h of aging and different composite resins with same hue, presented different colors before being subjected to the aging process (B2 and C2 and after (B2. It was also observed color difference within a group of the same composite resin and same hue.

  1. 40 CFR 721.4380 - Modified hydrocarbon resin.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified hydrocarbon resin. 721.4380... Substances § 721.4380 Modified hydrocarbon resin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified hydrocarbon resin (P-91-1418)...

  2. 21 CFR 872.3820 - Root canal filling resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Root canal filling resin. 872.3820 Section 872.3820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a...

  3. 40 CFR 721.3135 - Phosphorous modified epoxy resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phosphorous modified epoxy resin... Specific Chemical Substances § 721.3135 Phosphorous modified epoxy resin (generic). (a) Chemical substance... phosphorous modified epoxy resin (PMNs P-00-992 and P-01-471) is subject to reporting under this section...

  4. 76 FR 39896 - Granular Polytetrafluoroethylene Resin From Italy

    Science.gov (United States)

    2011-07-07

    ... COMMISSION Granular Polytetrafluoroethylene Resin From Italy Determination On the basis of the record \\1... antidumping duty order on granular polytetrafluoroethylene resin from Italy would be likely to lead to... Granular Polytetrafluoroethylene Resin from Italy: Investigation No. 731-TA-385 (Third Review). By order...

  5. 40 CFR 721.9499 - Modified silicone resin.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified silicone resin. 721.9499... Substances § 721.9499 Modified silicone resin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified silicone resin (PMN P-96-1649)...

  6. 75 FR 67105 - Granular Polytetrafluoroethylene Resin From Italy and Japan

    Science.gov (United States)

    2010-11-01

    ... COMMISSION Granular Polytetrafluoroethylene Resin From Italy and Japan AGENCY: United States International... granular polytetrafluoroethylene resin from Italy and Japan. SUMMARY: The Commission hereby gives notice... polytetrafluoroethylene resin from Italy and Japan would be likely to lead to continuation or recurrence of...

  7. 40 CFR 721.5908 - Modified phenolic resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified phenolic resin (generic). 721... Substances § 721.5908 Modified phenolic resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as modified phenolic resin (PMN...

  8. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylamide-acrylic acid resins. 176.110 Section 176... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in...

  9. 21 CFR 177.2510 - Polyvinylidene fluoride resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyvinylidene fluoride resins. 177.2510 Section... as Components of Articles Intended for Repeated Use § 177.2510 Polyvinylidene fluoride resins. Polyvinylidene fluoride resins may be safely used as articles or components of articles intended for repeated...

  10. 21 CFR 872.3300 - Hydrophilic resin coating for dentures.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hydrophilic resin coating for dentures. 872.3300... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3300 Hydrophilic resin coating for dentures. (a) Identification. A hydrophilic resin coating for dentures is a device that consists of a...

  11. 21 CFR 177.1650 - Polysulfide polymer-polyepoxy resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polysulfide polymer-polyepoxy resins. 177.1650...-polyepoxy resins. Polysulfide polymer-polyepoxy res- ins may be safely used as the food-contact surface of... with the following prescribed conditions: (a) Polysulfide polymer-polyepoxy resins are the...

  12. 40 CFR 721.2673 - Aromatic epoxide resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic epoxide resin (generic). 721... Substances § 721.2673 Aromatic epoxide resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as aromatic epoxide resin (PMN...

  13. 21 CFR 177.2410 - Phenolic resins in molded articles.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Phenolic resins in molded articles. 177.2410... as Components of Articles Intended for Repeated Use § 177.2410 Phenolic resins in molded articles. Phenolic resins identified in this section may be safely used as the food-contact surface of...

  14. 21 CFR 177.2415 - Poly(aryletherketone) resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Poly(aryletherketone) resins. 177.2415 Section 177... Components of Articles Intended for Repeated Use § 177.2415 Poly(aryletherketone) resins. Poly(aryletherketone) resins identified in paragraph (a) of this section may be safely used as articles or...

  15. 40 CFR 721.5762 - Aromatic aldehyde phenolic resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic aldehyde phenolic resin... Specific Chemical Substances § 721.5762 Aromatic aldehyde phenolic resin (generic). (a) Chemical substance... aromatic aldehyde phenolic resin (PMN P-01-573) is subject to reporting under this section for...

  16. 21 CFR 175.270 - Poly(vinyl fluoride) resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Poly(vinyl fluoride) resins. 175.270 Section 175... Substances for Use as Components of Coatings § 175.270 Poly(vinyl fluoride) resins. Poly(vinyl fluoride) resins identified in this section may be safely used as components of food-contact coatings...

  17. 21 CFR 172.215 - Coumarone-indene resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Coumarone-indene resin. 172.215 Section 172.215... CONSUMPTION Coatings, Films and Related Substances § 172.215 Coumarone-indene resin. The food additive coumarone-indene resin may be safely used on grapefruit, lemons, limes, oranges, tangelos, and tangerines...

  18. 21 CFR 177.2500 - Polyphenylene sulfone resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyphenylene sulfone resins. 177.2500 Section 177... Components of Articles Intended for Repeated Use § 177.2500 Polyphenylene sulfone resins. The polyphenylene sulfone resins (CAS Reg. No. 31833-61-1) identified in paragraph (a) of this section may be safely used...

  19. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Temporary crown and bridge resin. 872.3770 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device composed of a material, such...

  20. 40 CFR 721.5905 - Modified phenolic resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified phenolic resin (generic). 721... Substances § 721.5905 Modified phenolic resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified phenolic resin...

  1. 21 CFR 173.10 - Modified polyacrylamide resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Modified polyacrylamide resin. 173.10 Section 173... CONSUMPTION Polymer Substances and Polymer Adjuvants for Food Treatment § 173.10 Modified polyacrylamide resin. Modified polyacrylamide resin may be safely used in food in accordance with the following...

  2. 21 CFR 173.40 - Molecular sieve resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Molecular sieve resins. 173.40 Section 173.40 Food... Polymer Substances and Polymer Adjuvants for Food Treatment § 173.40 Molecular sieve resins. Molecular sieve resins may be safely used in the processing of food under the following prescribed conditions:...

  3. 21 CFR 872.3690 - Tooth shade resin material.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3690 Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of materials such as bisphenol-A glycidyl... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tooth shade resin material. 872.3690 Section...

  4. 21 CFR 872.3670 - Resin impression tray material.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3670 Resin impression tray material. (a) Identification. Resin impression tray material is a device intended for use in a two-step dental mold fabricating... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Resin impression tray material. 872.3670...

  5. 21 CFR 872.3310 - Coating material for resin fillings.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3310 Coating material for resin fillings. (a) Identification. A coating material for resin fillings is a device intended to be applied to the... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Coating material for resin fillings....

  6. TRIMETHYLSILYLATED SILICA AS RHEOLOGY MODIFIER FOR SILICONE RESINS

    Institute of Scientific and Technical Information of China (English)

    Wei Huang; Ying Huang; Yunzhao Yu

    2000-01-01

    Trimethylsilylated silica was synthesized through hydrolytic condensation of tetraethoxysilane followed by trimethylsilylation. Rheological properties of the silicone resin with trimethylsilylated silica as modifier were studied. It turned out that the particle size of silica was important to the rheological behavior of the modified resin. Trimethylsilylated silica of medium particle size shows the strongest tendency of forming physical network in the resin.

  7. Solid-State Microwave Synthesis of Melamine-Formaldehyde Resin

    Directory of Open Access Journals (Sweden)

    Subhash Bajia

    2009-01-01

    Full Text Available An efficient synthesis of melamine-formaldehyde resin has been achieved using conventional as well as microwave irradiations (without and with solid support in different molar ratio. Resin samples were tested for their chemical as well as physical properties. The structure of all the resin has been supported by their spectral data

  8. Progress of the Application of Mesoporous Silica-Supported Heteropolyacids in Heterogeneous Catalysis and Preparation of Nanostructured Metal Oxides

    Directory of Open Access Journals (Sweden)

    Heyong He

    2010-01-01

    Full Text Available Mesoporous silica molecular sieves are a kind of unique catalyst support due to their large pore size and high surface area. Several methods have been developed to immobilize heteropolyacids (HPAs inside the channels of these mesoporous silicas. The mesoporous silica-supported HPA materials have been widely used as recyclable catalysts in heterogeneous systems. They have shown high catalytic activities and shape selectivities in some reactions, compared to the parent HPAs in homogeneous systems. This review summarizes recent progress in the field of mesoporous silica-supported HPAs applied in the heterogeneous catalysis area and preparation of nanostructured metal oxides using HPAs as precursors and mesoporous silicas as hard templates.

  9. Aromatization of alkanes over Pt promoted conventional and mesoporous gallosilicates of MEL zeolite

    KAUST Repository

    Akhtar, M. N.

    2012-01-01

    Aromatization of hexane and propane was investigated over Pt promoted mesoporous gallium-containing HZSM-11 with controlled mesoporosity generated by desilication. Prepared catalysts were characterized by nitrogen adsorption, X-ray powder diffraction, scanning electron microscopy, Fourier transform infrared of chemisorbed pyridine, and NH 3 temperature programmed desorption confirming the development of intracrystalline mesoporosity of Ga-containing HZSM-11. The catalytic activities, which were compared in the aromatization of n-hexane and propane, increased upon desilication. The aromatization of n-hexane decreased in the following order, Pt/mesoporous GaZSM-11 Pt/conventional GaZSM-11 mesoporous GaZSM-11 > conventional GaZSM-11. Hexane conversion reached 70.1% over mesoporous Pt/GaZSM-11 with Si/Ga of 61, as compared with 29.6 and 24.9% for corresponding mesoporous and conventional GaZSM-11 (Si/Ga = 94), respectively, for experiments at liquid hour space velocity of 3.6 h -1, and 540 °C. Comparison of BTX (benzene-toluene-xylene) selectivity at the conversion level of ∼21.0% revealed that Pt/mesoporous GaZSM-11 is more selective than corresponding mesoporous and conventional GaZSM-11. The BTX selectivity over Pt/mesoporous GaZSM-11 (Si/Ga = 94), which showed strong dependence on the conversion, reached 28.2%, whereas over corresponding mesoporous and conventional GaZSM-11catalysts reached 19.1% and 5.5%, respectively. A higher conversion and better selectivity can be attributed to the improved accessibility to the active extra-framework Ga species owing to the generation of mesopores inside the zeolite particles and shortening the contact time. It is worth mentioning that the prepared catalysts exhibited quite low activity in propane aromatization but exhibiting similar trends as for hexane aromatization. © 2011 Elsevier B.V. All rights reserved.

  10. A stand-alone mesoporous crystal structure model from in situ X-ray diffraction: nitrogen adsorption on 3D cagelike mesoporous silica SBA-16.

    Science.gov (United States)

    Miyasaka, Keiichi; Hano, Hiroko; Kubota, Yoshiki; Lin, Yangzheng; Ryoo, Ryong; Takata, Masaki; Kitagawa, Susumu; Neimark, Alexander V; Terasaki, Osamu

    2012-08-13

    We present a modeling scheme to analyze cagelike silica mesoporous crystals based on in situ X-ray diffraction (XRD) data collected during gas adsorption-desorption (physisorption) processes. Nitrogen physisorption on a silica mesoporous crystal of SBA-16 was directly monitored by using synchrotron in situ powder XRD measurements conducted at SPring-8. SBA-16 is a well-ordered mesoporous silica in which three-dimensional interconnected cagelike primary mesopores are located at the body-centered cubic lattice points. In addition, the surrounding silica matrix contains random microporous and mesoporous intrawall porosities that are significantly influential to the diffusion properties, and thus important to be quantified for this media. The in situ XRD data exhibits seven Bragg reflections throughout the measurements, and the present method allows one to obtain the maximal and stand-alone information about the pore structure (for example, the mesopore size, the matrix density, the intrawall porosity, and pore surface roughness) together with the nitrogen film evolution in the primary mesopores and the intrawall pore-filling in the silica matrix. We furthermore observe a macroscopic amount of nitrogen adsorbed assuming the density of the fluid, and confirm that the XRD "isotherm" recalculated from the analysis result is consistent with the conventional nitrogen isotherm on a semi-quantitative level; however, these results suggest that the intrawall pores would have a greater contribution to the adsorption than considered based on the conventional isotherm analyses. The present method is readily extendable to any ordered mesopores wrapped by the wall matrix containing a certain intrawall porosity.

  11. Dual-mesoporous ZSM-5 zeolite with highly b-axis-oriented large mesopore channels for the production of benzoin ethyl ether.

    Science.gov (United States)

    Zhou, Xiaoxia; Chen, Hangrong; Zhu, Yan; Song, Yudian; Chen, Yu; Wang, Yongxia; Gong, Yun; Zhang, Guobin; Shu, Zhu; Cui, Xiangzhi; Zhao, Jinjin; Shi, Jianlin

    2013-07-22

    Dual-mesoporous ZSM-5 zeolite with highly b axis oriented large mesopores was synthesized by using nonionic copolymer F127 and cationic surfactant CTAB as co-templates. The product contains two types of mesopores--smaller wormlike ones of 3.3 nm in size and highly oriented larger ones of 30-50 nm in diameter along the b axis--and both of them interpenetrate throughout the zeolite crystals and interconnect with zeolite microporosity. The dual-mesoporous zeolite exhibits excellent catalytic performance in the condensation of benzaldehyde with ethanol and greater than 99 % selectivity for benzoin ethyl ether at room temperature, which can be ascribed to the zeolite lattice structure offering catalytically active sites and the hierarchical and oriented mesoporous structure providing fast access of reactants to these sites in the catalytic reaction. The excellent recyclability and high catalytic stability of the catalyst suggest prospective applications of such unique mesoporous zeolites in the chemical industry.

  12. Nano-hard template synthesis of pure mesoporous NiO and its application for streptavidin protein immobilization.

    Science.gov (United States)

    Wahab, Mohammad A; Darain, Farzana

    2014-04-25

    A simple and efficient immobilization of streptavidin protein (with hexa-histidine tag) onto the surface of mesoporous NiO is described. Before immobilization of streptavidin protein (with hexa-histidine tag) onto the surface of mesoporous NiO, we first synthesized well-organized mesoporous NiO by a nanocasting method using mesoporous silica SBA-15 as the hard template. Then, the well-organized mesoporous NiO particles were characterized by small angle x-ray diffraction (XRD), wide angle XRD, nitrogen adsorption/desorption, and transmission electron microscopy (TEM). TEM and small angle XRD suggested the formation of mesoporous NiO materials, whereas the wide angle XRD pattern of mesoporous NiO indicated that the nickel precursor had been transformed into crystalline NiO. The N2 sorption experiments demonstrated that the mesoporous NiO particles had a high surface area of 281 m2 g(-1), a pore volume of 0.51 cm3 g(-1) and a pore size of 4.8 nm. Next, the immobilization of streptavidin protein (with hexa-histidine tag) onto the surface of mesoporous NiO was studied. Detailed analysis using gel electrophoresis confirmed that this approach can efficiently bind his-tagged streptavidin onto the surface of mesoporous NiO material since the mesoporous NiO provides sufficient surface sites for the binding of streptavidin via non-covalent ligand binding with the histidine tag.

  13. Synthesis and characterization of resorcinol-formaldehyde resin chars doped by zinc oxide

    Science.gov (United States)

    Gun'ko, Vladimir M.; Bogatyrov, Viktor M.; Oranska, Olena I.; Urubkov, Iliya V.; Leboda, Roman; Charmas, Barbara; Skubiszewska-Zięba, Jadwiga

    2014-06-01

    Polycondensation polymerization of resorcinol-formaldehyde (RF) mixtures in water with addition of different amounts of zinc acetate and then carbonization of dried gels are studied to prepare ZnO doped chars. Zinc acetate as a catalyst of resorcinol-formaldehyde polycondensation affects structural features of the RF resin (RFR) and, therefore, the texture of chars prepared from Zn-doped RFR. The ZnO doped chars are characterized using thermogravimetry, low temperature nitrogen adsorption/desorption, Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HRTEM). At a relatively high content of zinc acetate (1 mol per 10-40 mol of resorcinol) in the reaction mixture, the formation of crystallites of ZnO (zincite) occurs in a shape of straight nanorods of 20-130 nm in diameter and 1-3 μm in length. At a small content of zinc acetate (1 mol per 100-500 mol of resorcinol), ZnO in composites is XRD amorphous and does not form individual particles. The ZnO doped chars are pure nanoporous at a minimal ZnO content and nano-mesoporous or nano-meso-macroporous at a higher ZnO content.

  14. Synthesis and characterization of resorcinol–formaldehyde resin chars doped by zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Gun’ko, Vladimir M., E-mail: vlad_gunko@ukr.net [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kyiv (Ukraine); Bogatyrov, Viktor M.; Oranska, Olena I. [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kyiv (Ukraine); Urubkov, Iliya V. [Kurdyumov Institute of Metal Physics, 36 Vernadsky Boulevard, 03142 Kyiv (Ukraine); Leboda, Roman; Charmas, Barbara; Skubiszewska-Zięba, Jadwiga [Faculty of Chemistry, Maria Curie-Skłodowska University, 20031 Lublin (Poland)

    2014-06-01

    Polycondensation polymerization of resorcinol–formaldehyde (RF) mixtures in water with addition of different amounts of zinc acetate and then carbonization of dried gels are studied to prepare ZnO doped chars. Zinc acetate as a catalyst of resorcinol–formaldehyde polycondensation affects structural features of the RF resin (RFR) and, therefore, the texture of chars prepared from Zn-doped RFR. The ZnO doped chars are characterized using thermogravimetry, low temperature nitrogen adsorption/desorption, Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HRTEM). At a relatively high content of zinc acetate (1 mol per 10–40 mol of resorcinol) in the reaction mixture, the formation of crystallites of ZnO (zincite) occurs in a shape of straight nanorods of 20–130 nm in diameter and 1–3 μm in length. At a small content of zinc acetate (1 mol per 100–500 mol of resorcinol), ZnO in composites is XRD amorphous and does not form individual particles. The ZnO doped chars are pure nanoporous at a minimal ZnO content and nano-mesoporous or nano-meso-macroporous at a higher ZnO content.

  15. Effect of epoxy resin properties on the mechanical properties of carbon fiber/epoxy resin composites

    Energy Technology Data Exchange (ETDEWEB)

    He, Hong-Wei; Gao, Feng [Taiyuan Univ. of Technology (China). College of Materials Science and Engineering; Taiyuan Univ. of Technology (China). Key Laboratory of Interface Science and Engineering in Advanced Materials; Li, Kai-Xi [Chinese Academy of Sciences, Taiyuan, Shanxi (China). Key Laboratory of Carbon Materials

    2013-09-15

    Three kinds of epoxy resins, i.e. tetraglycidyl diaminodiphenyl methane (AG80), difunctional diglycidyl ether of bisphenol-A (E51) and novolac type epoxy resin (F46) were selected as matrices for carbon fiber/epoxy composites. The objective of this work is to study the mechanical properties of fiber/epoxy composites by using these three kinds of epoxy resins with different physical and chemical performance. The results show that the composites fabricated with AG80 present the best stiffness and the composites prepared with E5 1have the best toughness. The stiffness and toughness of the composites prepared with F46 are middle values located between those for AG80/epoxy and E51/epoxy composites. Thus, the mixed epoxy resin is a promising approach for industrial production. (orig.)

  16. Syntheses of SBA-15 and Investigation on Properties of E-127 Epoxy Resin System%介孔SBA-15/环氧树脂复合材料的性能研究

    Institute of Scientific and Technical Information of China (English)

    陈书文; 王雁冰; 黄志雄; 张超

    2011-01-01

    Using ultrasonic dispersion method, the synthesized mesoporous silica SBA-15 can fully dispersed in the epoxy resin, and then we can get SBA-15/epoxy composite materials.Condition of the filler dispersion in the resin was investigated by XRD analysis;meanwhile, characteristics of epoxy resin were researched by dielectrics constant and thermal gravimetric analysis.The research shows that SBA-15 filler can improve the thermal stability of epoxy resin and reduce its dielectric constant.%合成了孔径SBA-15介孔二氧化硅材料,利用超声波分散法制得了SBA-15/环氧树脂复合材料,TEM和氮气吸附脱附测试显示制备的SBA-15孔径为5 nm.通过SEM测试观察了介电复合材料中填料的分散情况;同时采用热失重分析、介电常数测定等方法对该介电复合材料的性能进行了研究.结果表明:SBA-15粒子的填充,可以提高环氧树脂的热稳定性,降低其介电常数.

  17. A temporary space maintainer using acrylic resin teeth and a composite resin.

    Science.gov (United States)

    Kochavi, D; Stern, N; Grajower, R

    1977-05-01

    A one-session technique for preparing a temporary space maintainer has been described. The technique consists of attaching an acrylic resin pontic to etched surfaces of natural adjacent teeth by means of a composite resin. The main advantages of this technique are elimination of premature tooth preparation, good esthetics, fair strength, low cost, and rapid completion of the restoration without the need of a dental laboratory.

  18. [Studies of dental methacrylic resin. (Part 8) Flexural and impact adhesive strength of self-curing methacrylic resin to cross-linked polymethyl methacrylate resins (author's transl)].

    Science.gov (United States)

    Hirasawa, T; Hirabayashi, S; Harashima, I

    1981-10-01

    Heat-curing methacylic resins cross-linked with three kinds of dimethacrylates, i.e. EDMA, tri-EDMA and nona-EDMA, were prepared, and the flexural and the impact adhesive strength of the dough moulding type and the pour type self-curing methacrylic resins to them were examined. The results obtained were as follows. (1) The flexural and the impact adhesive strength of the pour type self-curing resin were higher and more stable than those of the dough moulding type one. (2) The flexural and the impact adhesive strength of self-curing resins to cross-linked adherent resins rised in order of nona-EDMA greater than tri-EDMA greater than EDMA in the range of higher concentration of cross-linking agents. This tendency was marked for the pour type resin. (3) When the dough moulding type resin was used as adhesive resin, to adherent resin cross-linked with EDMA or tri-EDMA which had relatively short chain, the respective adhesive strength of that decreased with increasing the concentration of cross-linking agent. While, to adherent resin cross-linked with nona-EDMA, which had relatively long and more flexible chain, the respective adhesive strength of the dough moulding type resin increased with increasing the concentration of cross-linking agent. (4) When the pour type resin was used as adhesive resin, to adherent resin cross-linked with EDMA or tri-EDMA, the respective adhesive strength of that showed the maximum at the concentration near 2 to 5 mole% and decreased with increasing the concentration. While, to adherent resin cross-linked with nona-EDMA, the flexural adhesive strength of the pour type resin was approximately constant without the effect of the concentration, but the impact adhesive strength of that increased with increasing the concentration. (5) The flexural adhesive strength of the dough moulding and the pour type resin under the wet condition decreased about 30 to 60% compared with under the dry condition, but the percentage of the falling for the impact

  19. Preparation of montmorillonite modified phenolic resin for shell process

    Institute of Scientific and Technical Information of China (English)

    Xiong Jianmin; Li Yuancai; Wang Wenqing; Xia Chun

    2009-01-01

    The development of montmodllonite modified phenolic resin under microwave irradiation heating was investigated. The effect of montmorillonite content and stirring time on the structure and morphology of synthetic resin was analyzed. The optimum processing procedure was found to be 45 rain stirring time with 5.4% montmorillonite addition. Further, the platelet spacing increases with stirring time till montmorillonite exfoliated to nanoscales platelet. When montmorillonite is exfoliated, layered structure at nanoscale can be uniformly distributed in the resin. The overall performance of montmorillonite modified phenolic resin is improved remarkably, such as flow ability, tensile strength and toughness property of resin coated sand. However, the gelation speed decreased slightly by adding montmorillonite.

  20. NITRATE CONVERSION OF HB-LINE REILLEXTM HPQ RESIN

    Energy Technology Data Exchange (ETDEWEB)

    Steimke, J.; Williams, M.; Steeper, T.; Leishear, R.

    2012-05-29

    Reillex{trademark} HPQ ion exchange resin is used by HB Line to remove plutonium from aqueous streams. Reillex{trademark} HPQ resin currently available from Vertellus Specialties LLC is a chloride ionic form, which can cause stress corrosion cracking in stainless steels. Therefore, HB Line Engineering requested that Savannah River National Laboratory (SRNL) convert resin from chloride form to nitrate form in the Engineering Development Laboratory (EDL). To perform this task, SRNL treated two batches of resin in 2012. The first batch of resin from Reilly Industries Batch 80302MA was initially treated at SRNL in 2001 to remove chloride. This batch of resin, nominally 30 liters, has been stored wet in carboys since that time until being retreated in 2012. The second batch of resin from Batch 23408 consisted of 50 kg of new resin purchased from Vertellus Specialties in 2012. Both batches were treated in a column designed to convert resin using downflow of 1.0 M sodium nitrate solution through the resin bed followed by rinsing with deionized water. Both batches were analyzed for chloride concentration, before and after treatment, using Neutron Activation Analysis (NAA). The resin specification [Werling, 2003] states the total chlorine and chloride concentration shall be less than 250 ppm. The resin condition for measuring this concentration is not specified; however, in service the resin would always be fully wet. Measurements in SRNL showed that changing from oven dry resin to fully wet resin, with liquid in the particle interstices but no supernatant, increases the total weight by a factor of at least three. Therefore, concentration of chlorine or chloride expressed as parts per million (ppm) decreases by a factor of three. Therefore, SRNL recommends measuring chlorine concentration on an oven dry basis, then dividing by three to estimate chloride concentration in the fully wet condition. Chloride concentration in the first batch (No.80302MA) was nearly the same

  1. 21 CFR 177.1580 - Polycarbonate resins.

    Science.gov (United States)

    2010-04-01

    ... FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic..., manufacturing, packing, processing, preparing, treating, packaging, transporting, or holding food, in accordance... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polycarbonate resins. 177.1580 Section...

  2. Microbial treatment of ion exchange resins

    Energy Technology Data Exchange (ETDEWEB)

    Kouznetsov, A.; Kniazev, O. [D. Mendeleyev University of Chemical Technology of Russia, Dept. Biotechnology, Mocow (Russian Federation)

    2001-07-01

    A bioavailability of ion exchange resins to a microbial destruction as one of the alternative methods of compacting used ionites from the nuclear fuel manufacturing cycle enterprises has been investigated. The bio-destruction was studied after a preliminary chemical treatment or without it. A sensitivity of the ion exchange resins (including highly acidic cationite KU-2-8) to the microbial destruction by heterotrophic and chemo-litho-trophic microorganisms under aerobic conditions was shown in principle. The biodegradation of the original polymer is possible in the presence of the water soluble fraction of the resin obtained after its treatment by Fenton reagent and accelerated in the presence of Mn-ions in optimal concentration 1-2 g of Mn per liter of medium. Thus, the process of bio-destruction of ionite polymer by heterotrophic microorganisms can be compared with the bio-destruction of lignin or humic substances. The optimum parameters of bio-destruction and microorganisms used must be different for resins with different functional groups. (authors)

  3. Resin diffusion through demineralized dentin matrix

    Directory of Open Access Journals (Sweden)

    CARVALHO Ricardo M.

    1999-01-01

    Full Text Available This paper has focused on the factors that may affect the permeability of adhesive resins into the demineralized dentin matrix during the development of the bonding process. The effects of surface moisture are discussed respectively to the adhesive systems, and the problems related to incomplete hybrid layer formation presented.

  4. Pharmaceutical Applications of Ion-Exchange Resins

    Science.gov (United States)

    Elder, David

    2005-01-01

    The historical uses of ion-exchanged resins and a summary of the basic chemical principles involved in the ion-exchanged process are discussed. Specific applications of ion-exchange are provided that include drug stabilization, pharmaceutical excipients, taste-masking agents, oral sustained-release products, topical products for local application…

  5. Crack propagation directions in unfilled resins.

    Science.gov (United States)

    Baran, G; Sadeghipour, K; Jayaraman, S; Silage, D; Paul, D; Boberick, K

    1998-11-01

    Posterior composite restorative materials undergo accelerated wear in the occlusal contact area, primarily through a fatigue mechanism. To facilitate the timely development of new and improved materials, a predictive wear model is desirable. The objective of this study was to develop a finite element model enabling investigators to predict crack propagation directions in resins used as the matrix material in composites, and to verify these predictions by observing cracks formed during the pin-on-disc wear of a 60:40 BISGMA:TEGDMA resin and an EBPADMA resin. Laser confocal scanning microscopy was used to measure crack locations. Finite element studies were done by means of ABAQUS software, modeling a cylinder sliding on a material with pre-existing surface-breaking cracks. Variables included modulus, cylinder/material friction coefficient, crack face friction, and yield behavior. Experimental results were surprising, since most crack directions were opposite previously published observations. The majority of surface cracks, though initially orthogonal to the surface, changed direction to run 20 to 30 degrees from the horizontal in the direction of indenter movement. Finite element modeling established the importance of subsurface shear stresses, since calculations provided evidence that cracks propagate in the direction of maximum K(II)(theta), in the same direction as the motion of the indenter, and at an angle of approximately 20 degrees. These findings provide the foundation for a predictive model of sliding wear in unfilled glassy resins.

  6. Evaluation of resins for use in brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Luiz Claudio F.M. Garcia; Ferraz, Wilmar Barbosa; Chrcanovic, Bruno Ramos; Santos, Ana Maria M., E-mail: ferrazw@cdtn.b, E-mail: amms@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    Brachytherapy is an advanced cancer treatment where radioactive seeds or sources are placed near or directly into the tumor thus reducing the radiation exposure in the surrounding healthy tissues. Prostate cancer can be treated with interstitial brachytherapy in initial stage of the disease in which tiny radioactive seeds with cylindrical geometry are used. Several kinds of seeds have been developed in order to obtain a better dose distribution around them and with a lower cost manufacturing. These seeds consist of an encapsulation, a radionuclide carrier, and X-ray marker. Among the materials that have potential for innovation in the construction of seeds, biocompatible resins appear as an important option. In this paper, we present some characterization results with Fourier transform infrared spectroscopic (FTIR) and ultraviolet-visible spectroscopy (UV-vis) performed on two types of resins in which curing temperatures for each one were varied as also the results of coatings with these resins under titanium substrates. Interactions of these resins in contact with the simulated body fluid were evaluated by atomic force microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. (author)

  7. Hyperbranched Polymers for Resin Transfer Molding

    Science.gov (United States)

    2005-03-01

    refereed journals and referencing AFOSR support: 6 H. Qin, P.T. Mather, J.-B. Baek, and L.-S. Tan, "Modification of bisphenol-A based bismaleimide resin...Burstone, "Shape Memory Polymer Orthodontics ," SPE ANTEC Medical Plastics Division, May 9, 2006. b. Consultation and Advisory Functions with other

  8. 21 CFR 177.1380 - Fluorocarbon resins.

    Science.gov (United States)

    2010-04-01

    ... HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components...) Chlorotrifluoroethylene-1,1-difluoroethylene-tetrafluoroethylene co-polymer resins produced by copolymerization of..., Extrusion, and Coating Materials,” which is incorporated by reference in accordance with 5 U.S.C. 552(a)...

  9. Selective catalysis utilizing bifunctionalized MCM-41 mesoporous materials

    Energy Technology Data Exchange (ETDEWEB)

    Strosahl, Kasey Jean [Iowa State Univ., Ames, IA (United States)

    2005-01-01

    Selective catalysis is a field that has been under intense investigation for the last 100 years. The most widely used method involves catalysts with stereochemical selectivity. In this type of catalysis, the catalyst controls which reactants will be transformed into the desired product. The secret to employing this type of catalysis, though, is to design the proper catalyst, which can be difficult. One may spend as much time developing the catalyst as spent separating the various products achieved. Another method of selective catalysis is now being explored. The method involves utilizing a multifunctional mesoporous silica catalyst with a gate-keeping capability. Properly functionalized mesoporous materials with well-defined pore morphology and surface properties can provide an ideal three-dimensional environment for anchoring various homogeneous catalysts. These materials can circumvent the multi-sited two-dimensional nature most heterogeneous systems have without adversely impacting the reactant diffusivity. These single-site nanostructured catalysts with ordered geometrical structure are advantageous in achieving high selectivity and reactivity. Mesoporous materials can be prepared to include pores lined homogeneously with tethered catalysts via co-condensation. Additionally, these materials can be reacted with another (RO)3Si~Z group by using the traditional grafting method; this group is anchored predominantly at the entrances to the pores rather than inside the pores. Thus, if these ~Z groups are chosen properly, they can select certain molecules to enter the pores and be converted to products (Scheme 1). In such multifunctional catalysts, the selectivity depends on the discrimination of the gatekeeper. Gate-keeping MCM-41 materials are at the forefront of catalytic substances.

  10. Photochromic ordered mesoporous hybrid materials based on covalently grafted polyoxometalates.

    Science.gov (United States)

    Luo, Xiujuan; Yang, Chun

    2011-05-07

    Novel polyoxometalate (POM)-grafting mesoporous hybrid silicas, XW(11)/MHS (X=P, Si) and TBAPW(11)Si(2)/MHS, have been prepared respectively by co-condensation and post-synthesis routes based on the employment of Keggin-type monovacant XW(11) or a Si-substituted compound TBAPW(11)Si(2) as POM precursors. Upon characterization of the samples by FT-IR, XRD, ICP-AES, TEM and N(2) adsorption-desorption measurement, it was found that Keggin units were retained perfectly in ordered hexagonal mesopore channels with SBA-15 architecture and immobilized by covalent linkages on the mesopore wall. These materials, especially the co-condensed samples, exhibited stable and reversible photochromic properties under UV irradiation although no special organic component was supplied additionally as an electron donor. An investigation of the photochromism revealed that the photochromic response depended on the centre atom of the POM species (i.e., the redox potential of the POM), the content of the POM and the synthetic route of the sample, while the bleaching process was correlated not only to the redox potential but also to the pore size of the sample. The photochromic mechanism was also studied in detail by cyclic voltammetry, ESR, FT-IR and XPS techniques. It was found that the remaining P123 template acted as a reducing agent and was oxidized during the photochromic process accompanied by the reduction of the POM to heteropolyblue. Thus, a close contact between the POM and the remaining P123 chain in the sample is necessary. Low close-contact degree results in poor photochromic behavior of the post-synthesized sample and impregnated samples.

  11. Silver nanoparticles incorporated onto ordered mesoporous silica from Tollen's reagent

    Science.gov (United States)

    Zienkiewicz-Strzałka, M.; Pasieczna-Patkowska, S.; Kozak, M.; Pikus, S.

    2013-02-01

    Noble metal nanostructures supported on mesoporous silica are bridge between traditional silica adsorbents and modern catalysts. In this work the Ag/SBA-15 mesoporous materials were synthesized and characterized. Various forms of nanosilver supported on ordered mesoporous template have been successfully obtained via proposed procedures. In all synthesized materials, Tollen's reagent (diammine silver complex [Ag(NH3)2]+) was used as a silver source. Silver nanoparticles were prepared by reduction of ammoniacal silver complex by formaldehyde in the solution of stabilizer. After reduction, Ag nanoparticles could be deposited on SBA-15, or added during traditional synthesis of SBA-15 giving silver or silver chloride nanoparticles in the combination with porous silica. Silver nanostructures as nanoparticles or nanowires were also embedded onto the SBA-15 by incipient wetness impregnation of silver ions. Absorbed silver ions were next reduced under hydrogen at high temperature. There are many advantages of utilized ammoniacal silver complex as a silver source. Proposed method is capable to synthesis of various metal nanostructures with controlled composition and morphology. The silver ammonia complex is composed of two ions surrounding and protecting the central silver ion, so it is possible to obtain very small nanoparticles using simple approach without any functionalization of external and internal surface of SBA-15. This approach allows obtaining greatly small silver nanoparticles on SBA-15 (4 nm) or nanowires depending on the metal loading amount. Moreover, the colloidal silver solution prepared from Tollen's reagent, in the presence of triblock copolymer, remains stable for a long time. Reduction of Tollen's reagent to silver colloidal solution seems to be efficient, fast and interesting approach for the preparation of supported silver nanostructures Obtained samples were characterized by powder X-ray diffraction, small angle X-ray scattering (SAXS), UV

  12. Bisphenol-A epoxy resin reinforced and toughened by hyperbranched epoxy resin

    Institute of Scientific and Technical Information of China (English)

    ZHANG Daohong; JIA Demin; HUANG Xianbo

    2007-01-01

    The study on toughening and reinforcing of bisphenol-A epoxy resin is one of important developmental direction in the field.This paper reports a one-pot synthesis of aromatic polyester hyperbranched epoxy resin HTDE-2,an effect of HTDE-2 content on the mechanical and thermal performance of the bisphenol-A (E51)/HTDE-2 hybrid resin in detail.Fourier transform infrared (FT-IR) spectrometer,scanning electronic microscopy (SEM),differential scanning calorimetry (DSC),thermogravimetric analysis (TGA),dynamic mechanical thermal analysis (DMA) and molecular simulation technology are used to study the structure of HTDE-2,performance and toughening and reinforcing mechanism of the HTDE-2/E51 hybrid resin.It has been shown that the content of HTDE-2 has an important effect on the performance of the hybrid resin,and the performance of the HTDE-2/E51 blends has maximum with the increase in HTDE-2 content.The impact strength and fracture toughness of the hybrid resin with 9 wt-% HTDE-2 are almost 3.088 and 1.749 times of E51 performance respectively,furthermore,the tensile and flexural strength can also be enhanced about 20.7% and 14.2%,respectively.The glass transition temperature and thermal degradation temperature,however,are found to decrease to some extent.

  13. Curing depth of a resin-modified glass ionomer and two resin-based luting agents.

    Science.gov (United States)

    Sigemori, Ricardo Massao; Reis, André Figueiredo; Giannini, Marcelo; Paulillo, Luís Alexandre M S

    2005-01-01

    The degree of conversion of resin-based luting agents used for retention of prefabricated posts has been questioned due to the difficulty of light penetration into the resin-filled root canal. This study evaluated the depth of cure of a resin-modified glass ionomer cement (Rely X--3M ESPE) and two resin-based luting agents (Rely X ARC--3M ESPE and Enforce-Dentsply). Twenty-four 14x2x2mm3 specimens were prepared in a Teflon split mold with the three luting agents (n=8). After preparation, the specimens were stored at 37 degrees C in a dark box for 24 hours prior to microhardness testing. Measurements of Knoop hardness were performed at three different depths: superficial, medium and deep thirds. The results (KHN) were statistically analyzed by repeated measures ANOVA and Tukey test (0.05), which showed that resin-based luting agents presented the highest Knoop hardness values within the superficial third. Within the medium third, there were no significant differences among luting materials. However, within the deep third, Rely X presented the highest values. KHN values of resin-based luting agents decreased remarkably as depth increased.

  14. The influence of a packable resin composite, conventional resin composite and amalgam on molar cuspal stiffness.

    Science.gov (United States)

    Molinaro, J D; Diefenderfer, K E; Strother, J M

    2002-01-01

    Packable resin composites may offer improved properties and clinical performance over conventional resin composites or dental amalgam. This in vitro study examined the cuspal stiffness of molars restored with a packable resin composite, a conventional posterior microfilled resin composite and amalgam. Forty-eight intact caries-free human third molars were distributed into four treatment groups (n=12) so that the mean cross-sectional areas of all groups were equal. Standardized MOD cavity preparations were made and specimens restored using one of four restorative materials: (1) a spherical particle amalgam (Tytin); (2) Tytin amalgam with a dentin adhesive liner (OptiBond Solo); (3) a conventional microfilled posterior resin composite (Heliomolar); (4) a packable posterior resin composite (Prodigy Posterior). Cuspal stiffness was measured using a Bionix 200 biomaterials testing machine (MTS). Specimens were loaded vertically to 300 N at a crosshead speed of 1.0 mm/minute. Stiffness was measured at 10 intervals: (1) prior to cavity preparation (intact); (2) following cavity preparation, but before restoration; (3) seven days after restoration; then (4) 1, 2, 3, 4, 5, 6 and 12 months after restoration. All specimens were stored at 37 degrees C in deionized water throughout the study and thermocycled (5 degrees/55 degrees C; 2000 cycles) monthly for 12 months. Repeated Measures ANOVA revealed significant differences among treatment groups over time (presin composite increased cuspal stiffness over that of amalgam.

  15. Mesoporous silica nanoparticles for biomedical and catalytical applications

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xiaoxing [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    Mesoporous silica materials, discovered in 1992 by the Mobile Oil Corporation, have received considerable attention in the chemical industry due to their superior textual properties such as high surface area, large pore volume, tunable pore diameter, and narrow pore size distribution. Among those materials, MCM-41, referred to Mobile Composition of Matter NO. 41, contains honeycomb liked porous structure that is the most common mesoporous molecular sieve studied. Applications of MCM-41 type mesoporous silica material in biomedical field as well as catalytical field have been developed and discussed in this thesis. The unique features of mesoporous silica nanoparticles were utilized for the design of delivery system for multiple biomolecules as described in chapter 2. We loaded luciferin into the hexagonal channels of MSN and capped the pore ends with gold nanoparticles to prevent premature release. Luciferase was adsorbed onto the outer surface of the MSN. Both the MSN and the gold nanoparticles were protected by poly-ethylene glycol to minimize nonspecific interaction of luciferase and keep it from denaturating. Controlled release of luciferin was triggered within the cells and the enzymatic reaction was detected by a luminometer. Further developments by varying enzyme/substrate pairs may provide opportunities to control cell behavior and manipulate intracellular reactions. MSN was also served as a noble metal catalyst support due to its large surface area and its stability with active metals. We prepared MSN with pore diameter of 10 nm (LP10-MSN) which can facilitate mass transfer. And we successfully synthesized an organo silane, 2,2'-Bipyridine-amide-triethoxylsilane (Bpy-amide-TES). Then we were able to functionalize LP10-MSN with bipyridinyl group by both post-grafting method and co-condensation method. Future research of this material would be platinum complexation. This Pt (II) complex catalyst has been reported for a C-H bond activation reaction as an

  16. Mesoporous tertiary oxides via a novel amphiphilic approach

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, Natasha; Hall, Simon R., E-mail: simon.hall@bristol.ac.uk, E-mail: Annela.Seddon@bristol.ac.uk [Bristol Centre for Functional Nanomaterials, Centre for Nanoscience and Quantum Information, Tyndall Avenue, Bristol BS8 1FD, United Kingdom and Complex Functional Materials Group, School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom); Seddon, Annela M., E-mail: simon.hall@bristol.ac.uk, E-mail: Annela.Seddon@bristol.ac.uk; Hallett, James E. [H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Kockelmann, Winfried [STFC Rutherford Appleton Laboratory, Chilton OX11 0QX (United Kingdom); Ting, Valeska P. [Department of Chemical Engineering, University of Bath, Bath BA2 7AY (United Kingdom); Sadasivan, Sajanikumari; Tooze, Robert P. [Sasol Technology (UK) Ltd, Purdie Building, North Haugh, St Andrews, Fife KY16 9ST (United Kingdom)

    2016-01-01

    We report a facile biomimetic sol-gel synthesis using the sponge phase formed by the lipid monoolein as a structure-directing template, resulting in high phase purity, mesoporous dysprosium- and gadolinium titanates. The stability of monoolein in a 1,4-butanediol and water mixture complements the use of a simple sol-gel metal oxide synthesis route. By judicious control of the lipid/solvent concentration, the sponge phase of monoolein can be directly realised in the pyrochlore material, leading to a porous metal oxide network with an average pore diameter of 10 nm.

  17. Mesoporous amine-bridged polysilsesquioxane for CO2 capture

    KAUST Repository

    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.

  18. PEG-templated mesoporous silica nanoparticles exclusively target cancer cells

    Science.gov (United States)

    Morelli, Catia; Maris, Pamela; Sisci, Diego; Perrotta, Enrico; Brunelli, Elvira; Perrotta, Ida; Panno, Maria Luisa; Tagarelli, Antonio; Versace, Carlo; Casula, Maria Francesca; Testa, Flaviano; Andò, Sebastiano; Nagy, Janos B.; Pasqua, Luigi

    2011-08-01

    Mesoporous silica nanoparticles (MSNs) have been proposed as DNA and drug delivery carriers, as well as efficient tools for fluorescent cell tracking. The major limitation is that MSNs enter cells regardless of a target-specific functionalization. Here we show that non functionalized MSNs, synthesized using a PEG surfactant-based interfacial synthesis procedure, do not enter cells, while a highly specific, receptor mediated, cellular internalization of folic acid (FOL) grafted MSNs (MSN-FOL), occurs exclusively in folate receptor (FR) expressing cells. Neither the classical clathrin pathway nor macropinocytosis is involved in the MSN endocytic process, while fluorescent MSNs (MSN-FITC) enter cells through aspecific, caveolae-mediated, endocytosis. Moreover, internalized particles seem to be mostly exocytosed from cells within 96 h. Finally, cisplatin (Cp) loaded MSN-FOL were tested on cancerous FR-positive (HeLa) or normal FR-negative (HEK293) cells. A strong growth arrest was observed only in HeLa cells treated with MSN-FOL-Cp. The results presented here show that our mesoporous nanoparticles do not enter cells unless opportunely functionalized, suggesting that they could represent a promising vehicle for drug targeting applications.Mesoporous silica nanoparticles (MSNs) have been proposed as DNA and drug delivery carriers, as well as efficient tools for fluorescent cell tracking. The major limitation is that MSNs enter cells regardless of a target-specific functionalization. Here we show that non functionalized MSNs, synthesized using a PEG surfactant-based interfacial synthesis procedure, do not enter cells, while a highly specific, receptor mediated, cellular internalization of folic acid (FOL) grafted MSNs (MSN-FOL), occurs exclusively in folate receptor (FR) expressing cells. Neither the classical clathrin pathway nor macropinocytosis is involved in the MSN endocytic process, while fluorescent MSNs (MSN-FITC) enter cells through aspecific, caveolae

  19. Stable Tetrahedral Aluminum Sites in Hexagonal Mesoporous Aluminosilicates

    Institute of Scientific and Technical Information of China (English)

    HAN,Yu(韩宇); YU,Yi(于沂); XU,Xian-Zhu(许宪祝); XIAO,Feng-Shou(肖丰收); LIU,Xian-Chun(刘宪春); HAN,Xiu-Wen(韩秀文); BAO,Xin-He(包信和)

    2002-01-01

    A unique templating approach for the synthesis of hexagonal mesoporous aluminosilicates via self-assembly of pre-formed aluminosilcate nanoclusters with the templating micella formed by cetyltrimethylammonium bromide (CTAB) is described.The obtained materials of MAS-5 are hydrothermally stable,which is shown by X-ray diffraction (XRD) analysis. Furthermore, as characterized by NMR technique, MAS-5 has stable tetrahedral aluminum sites that is the major contributions to the acidity of aluminosilicate molecular sieve, and on non-framework aluminium species in the samples was observed.

  20. SBA-15 mesoporous silica as a super insulating material

    Science.gov (United States)

    Belmoujahid, Y.; Bonne, M.; Scudeller, Y.; Schleich, D.; Grohens, Y.; Lebeau, B.

    2015-07-01

    The thermal insulation behavior of ordered mesoporous silica SBA-15 aggregates heat treated at 300 ∘C was studied. An important decrease in the effective thermal conductivity according to the increase of the apparent density was observed. A thermal conductivity value less than 25 mW.m-1.K-1 was reached during the compaction phenomenon. Results of thermal conductivity were correlated to the electron microscopy observations and physicochemical data (X-ray diffraction, adsorption/desorption of nitrogen volumetric measurements). These thermal properties make these materials very promising for thermal insulation applications, especially with values inferior to the thermal conductivity of air.

  1. Industrial water treatment, by adsorption, using organized mesoporous materials

    Science.gov (United States)

    Koubaissy, Bachar; Toufaily, Joumana; Kafrouny, Lina; Joly, Guy; Magnoux, Patrick; Hamieh, Tayssir

    In this work, pure silica SBA-15 was synthesized by a sol-gel method and in-situ functionalized by a series of organosilane. These mesoporous materials are used to absorb polluants from wastewater. We studied the influence of functional groups on adsorption of phenol drifts. The carboxylic acid groups and substituted chlorine on phenol have been studied. There is a sharp increase of adsorption (more than double compared to phenol) which is very encouraging. Furthermore we note that the percentage of grafted ligands also plays an important role in adsorption. Finally, the adsorption capacity also depends on the nature and percentage of ligands present.

  2. Heterogeneity of Energy and Geometry for Meso-porous Materials

    Institute of Scientific and Technical Information of China (English)

    Wenchuan Wang

    2004-01-01

    @@ The discovery of novel meso-porous materials having cylindrical and slit-like pores, such as zeolites,carbon nanotubes, activated carbon and meso-carbon microbeads (MCMBs), has aroused much attention in recent years. These materials are not only used directly as adsorbents, but also as substrates of catalysts for loading metals and other active substances.However, the description of heterogeneity of energy and of geometry of the pores is essential for characterization of these materials, and in computer simulations and density functional theory (DFT) calculation. Here, some approaches for dealing the heterogeneity are addressed for highlighting recent and future developments.

  3. Photocatalytic Cementitious Composites containing Mesoporous Titanium Dioxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    FALIKMAN Vyacheslav Ruvimovich

    2014-02-01

    Full Text Available The advanced method to produce nanoparticles of anatase mesoporous TiO₂ with high specific surface 300 m²/g has been developed. It was shown that titanium nanodioxide can be used in cement and gypsum composites as a highly efficient photocatalyst in the conversion processes of nitric oxide and volatile organic substances. Influence of radiation intensity, relative humidity, and concentration of contaminant and its stream speed on photocatalysis was studied. It was determined that efficiency of the composites with synthesized samples is 1,5–1,7 times higher than that of the commercial sample of the titanium nanodioxide.

  4. Characterization of a chiral nematic mesoporous organosilica using NMR

    Science.gov (United States)

    Manning, Alan; Shopsowitz, Kevin; Giese, Michael; MacLachlan, Mark; Dong, Ronald; Michal, Carl

    2012-10-01

    Using templation with nanocrystalline cellulose, a mesoporous organosilica film with a chiral nematic pore structure has recently been developed. [1] We have used a variety of Nuclear Magnetic Resonance (NMR) techniques to characterize the pore structure. The pore size distribution has been found by analyzing the freezing point depression of absorbed water via NMR cryoporometry. The effective longitudinal and transverse pore diameters for diffusing water were investigated with Pulsed-Field Gradient (PFG) NMR and compared to a 1-D connected-pore model. Preliminary data on testing imposed chiral ordering in absorbed liquid crystals is also presented. [4pt] [1] K.E. Shopsowitz et al. JACS 134(2), 867 (2012)

  5. Synthesis and in vitro bioactivity of mesoporous bioactive glass scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Shih, C.J., E-mail: cjshih@kmu.edu.tw [Department of Fragrance and Cosmetic Science, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Chen, H.T. [Department of Fragrance and Cosmetic Science, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Huang, L.F. [School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Lu, P.S.; Chang, H.F. [Department of Fragrance and Cosmetic Science, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Chang, I.L., E-mail: 84004@cch.org.tw [Department of Orthopaedic Surgery, Chang-Hua Christian Hospital, Changhua 500, Taiwan (China)

    2010-06-15

    The main objective of the present study was to determine the effect of thermal treatment procedures (calcination temperature, heating rate and duration time) on the synthesis of SiO{sub 2}-CaO-P{sub 2}O{sub 5} mesoporous bioactive glass scaffolds. This is accomplished by thermogravimetric analyses, Fourier transform infrared (FTIR) absorption spectra, X-ray diffraction (XRD) and by analysis of nitrogen adsorption/desorption isotherms. In vitro bioactivity can also be assessed by the cytotoxic effect of the glasses on the NIH-3T3 cell line, and by characterization of MC-3T3-E1 cell attachment.

  6. Stable Tetrahedral Aluminum Sites in Hexagonal Mesoporous Aluminosilicates

    Institute of Scientific and Technical Information of China (English)

    韩宇; 刘宪春; 等

    2002-01-01

    A unique templating approach for the synthesis of hexagonal mesoporous aluminosilicates via self-assembly of pre-formed aluminosilcate nacoclusters with the templating micella formed by cetyltrimethylammonium bromide (CTAB) is described ,The obtained materials of MAS-5 are hydrothermally stable,which is shown by X-ray diffraction (XRD) analysis,Further-more,as charaacterized by NMR technique ,MAS-5 has taable tetrahedral aluminum sites that is the major contributions to the acidity of aluminosilicate molecular sieve ,and on non-frame-work aluminium species in the saples was observed.

  7. Preparation and characterization of mesoporous tetragonal sulfated zirconia

    Institute of Scientific and Technical Information of China (English)

    Chun Xia He; Bin Yue; Ji Fang Cheng; Wei Ming Hua; Ying Hong Yue; He Yong He

    2009-01-01

    Mesoporous tetragonal sulfated zirconia with high surface area and narrow pore-size distribution was prepared using Zr(O-nPr)4 as zirconium precursor, sulfuric acid as sulfur source and triblock copolymer poly(ethylene glycol)-poly(propylene glycol)poly(ethylene glycol) (P123) as the template. The samples were characterized by X-ray diffraction, N2 sorption, TEM, and NH3TPD. A phase transformation from monoclinic sulfated zirconia to tetragonal sulfated zirconia is observed. The product shows strong acidity.

  8. [Antibacterial actions of denture base resin on oral bacteria].

    Science.gov (United States)

    Yamauchi, M; Nigauri, A; Yamamoto, K; Nakazato, G; Kawano, J; Kimura, K

    1989-06-01

    Antibacterial action of various denture base resins on thirteen species of bacteria were studied in vitro. Antibacterial effect of 5% tannin-fluoride preparation, 5% tannic acid and 5% chlorhexidine added to resins on these thirteen bacterial species were also investigated using heat-curing denture base resins. Fresh microwave-curing resin and pour-type resin each showed an antibacterial action on one bacterial strain. Fresh self-curing resins had antibacterial actions on several bacterial strains. However, after storage in water at 37 degrees C for one week, antibacterial action of microwave-curing and pour-type resin were diminished and self-curing resins partially lost their antibacterial actions. Denture base resin containing tannin-fluoride preparation or tannic acid showed an antibacterial effect on one bacterial strain. On the other hand, denture base resin containing chlorhexidine had an antibacterial action on eleven bacterial strains. However, color and mechanical properties of the drug-containing resins were not satisfactory.

  9. Synthesis and Characterizations of Melamine-Based Epoxy Resins

    Directory of Open Access Journals (Sweden)

    Raffaele Cioffi

    2013-09-01

    Full Text Available A new, easy and cost-effective synthetic procedure for the preparation of thermosetting melamine-based epoxy resins is reported. By this innovative synthetic method, different kinds of resins can be obtained just by mixing the reagents in the presence of a catalyst without solvent and with mild curing conditions. Two types of resins were synthesized using melamine and a glycidyl derivative (resins I or by adding a silane derivative (resin II. The resins were characterized by means of chemical-physical and thermal techniques. Experimental results show that all the prepared resins have a good thermal stability, but differ for their mechanical properties: resin I exhibits remarkable stiffness with a storage modulus value up to 830 MPa at room temperature, while lower storage moduli were found for resin II, indicating that the presence of silane groups could enhance the flexibility of these materials. The resins show a pot life higher than 30 min, which makes these resins good candidates for practical applications. The functionalization with silane terminations can be exploited in the formulation of hybrid organic-inorganic composite materials.

  10. Synthesis and characterizations of melamine-based epoxy resins.

    Science.gov (United States)

    Ricciotti, Laura; Roviello, Giuseppina; Tarallo, Oreste; Borbone, Fabio; Ferone, Claudio; Colangelo, Francesco; Catauro, Michelina; Cioffi, Raffaele

    2013-09-05

    A new, easy and cost-effective synthetic procedure for the preparation of thermosetting melamine-based epoxy resins is reported. By this innovative synthetic method, different kinds of resins can be obtained just by mixing the reagents in the presence of a catalyst without solvent and with mild curing conditions. Two types of resins were synthesized using melamine and a glycidyl derivative (resins I) or by adding a silane derivative (resin II). The resins were characterized by means of chemical-physical and thermal techniques. Experimental results show that all the prepared resins have a good thermal stability, but differ for their mechanical properties: resin I exhibits remarkable stiffness with a storage modulus value up to 830 MPa at room temperature, while lower storage moduli were found for resin II, indicating that the presence of silane groups could enhance the flexibility of these materials. The resins show a pot life higher than 30 min, which makes these resins good candidates for practical applications. The functionalization with silane terminations can be exploited in the formulation of hybrid organic-inorganic composite materials.

  11. ANALYSIS OF VENTING OF A RESIN SLURRY

    Energy Technology Data Exchange (ETDEWEB)

    Laurinat, J.; Hensel, S.

    2012-03-27

    A resin slurry venting analysis was conducted to address safety issues associated with overpressurization of ion exchange columns used in the Purex process at the Savannah River Site (SRS). If flow to these columns were inadvertently interrupted, an exothermic runaway reaction could occur between the ion exchange resin and the nitric acid used in the feed stream. The nitric acid-resin reaction generates significant quantities of noncondensable gases, which would pressurize the column. To prevent the column from rupturing during such events, rupture disks are installed on the column vent lines. The venting analysis models accelerating rate calorimeter (ARC) tests and data from tests that were performed in a vented test vessel with a rupture disk. The tests showed that the pressure inside the test vessel continued to increase after the rupture disk opened, though at a slower rate than prior to the rupture. Calculated maximum discharge rates for the resin venting tests exceeded the measured rates of gas generation, so the vent size was sufficient to relieve the pressure in the test vessel if the vent flow rate was constant. The increase in the vessel pressure is modeled as a transient phenomenon associated with expansion of the resin slurry/gas mixture upon rupture of the disk. It is postulated that the maximum pressure at the end of this expansion is limited by energy minimization to approximately 1.5 times the rupture disk burst pressure. The magnitude of this pressure increase is consistent with the measured pressure transients. The results of this analysis demonstrate the need to allow for a margin between the design pressure and the rupture disk burst pressure in similar applications.

  12. Resin Material Dependence of Pit Shape in Thermal Direct Mastering

    Science.gov (United States)

    Sakai, Toshihiko; Shimo, Masanori; Takamori, Nobuyuki; Murakami, Yoshiteru; Takahashi, Akira

    2007-06-01

    We report the resin material dependence of the shape of pits obtained by thermal direct mastering (TDM), which is a heat-mode mastering method utilizing the thermal decomposition of resins. By applying suitable resins, both circular and crescent pits can be obtained by TDM. This difference in shape was considered to originate from the temperature difference between the glass transition temperature and the thermal decomposition temperature of the resins. The resin with a relatively small temperature difference was suitable for the fabrication of the circular pits and random patterns, and the resin with a large temperature difference was suitable for the fabrication of the crescent pits and monotone patterns with high linear density. By using a deep ultraviolet (DUV) laser mastering system with a wavelength of 257 nm and a numerical aperture of 0.90, a monotone pattern of 40-nm-length pits was fabricated by applying a novolak-type resin with a relatively large temperature difference.

  13. FDI report on adverse reactions to resin-based materials.

    Science.gov (United States)

    Fan, P L; Meyer, D M

    2007-02-01

    Resin-based restorative materials are considered safe for the vast majority of dental patients. Although constituent chemicals such as monomers, accelerators and initiators can potentially leach out of cured resin-based materials after placement, adverse reactions to these chemicals are rare and reaction symptoms commonly subside after removal of the materials. Dentists should be aware of the rare possibility that patients could have adverse reactions to constituents of resin-based materials and be vigilant in observing any adverse reactions after restoration placement. Dentists should also be cognisant of patient complaints about adverse reactions that may result from components of resin-based materials. To minimise monomer leaching and any potential risk of dermatological reactions, resin-based materials should be adequately cured. Dental health care workers should avoid direct skin contact with uncured resin-based materials. Latex and vinyl gloves do not provide adequate barrier protection to the monomers in resin-based materials.

  14. Commercial Ion Exchange Resin Vitrification in Borosilicate Glass

    Energy Technology Data Exchange (ETDEWEB)

    Cicero-Herman, C.A.; Workman, P. [Westinghouse Savannah River Co., Aiken, SC (United States); Poole, K.; Erich, D.; Harden, J. [Clemson Environmental Technologies Laboratory, Anderson, SC (United States)

    1998-05-01

    Bench-scale studies were performed to determine the feasibility of vitrification treatment of six resins representative of those used in the commercial nuclear industry. Each resin was successfully immobilized using the same proprietary borosilicate glass formulation. Waste loadings varied from 38 to 70 g of resin/100 g of glass produced depending on the particular resin, with volume reductions of 28 percent to 68 percent. The bench-scale results were used to perform a melter demonstration with one of the resins at the Clemson Environmental Technologies Laboratory (CETL). The resin used was a weakly acidic meth acrylic cation exchange resin. The vitrification process utilized represented a approximately 64 percent volume reduction. Glass characterization, radionuclide retention, offgas analyses, and system compatibility results will be discussed in this paper.

  15. Polyelectrolytes from NS-novolak production waste

    Energy Technology Data Exchange (ETDEWEB)

    Bajdur, W.M.; Sulkowski, W.W. [Czestochowa Technical University, Dept. of Ergonomics and Work Protection, Czestochowa (Poland)

    2003-09-12

    The chemical modification of polymer plastic wastes into useful products, such as polyelectrolytes, could be a step toward their management. For these products to be obtained, the synthesis of amino derivatives of phenol-formaldehyde resin (NS-novolak) production waste by means of known methods was performed. Products that contained different contents of amino groups in the polymer chains and that were soluble in dilute KOH and NaOH solutions were obtained. The flocculation properties of these products were tested. Studies were conducted of mine water from the Kleofas coal mine and for water from the Czestochowa metallurgical plant blast-furnace circulation system. The amino derivatives of the phenol-formaldehyde resin waste were found to have good flocculation properties. The application of these products caused a decrease in the turbidity and concentration of the dissolved contamination and improved the quality parameters of the purified sewage. These polyelectrolytes could also be used in industrial water treatment.

  16. Polymerization of phenols catalyzed by peroxidase in nonaqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Dordick, J.S.; Marletta, M.A.; Klibanov, A.M.

    1987-01-01

    Polymers produced by horseradish-peroxidase-catalyzed coupling of phenols have been explored as potential substitutes for phenol-formaldehyde resins. To overcome low substrate solubilities and product molecular weights in water, enzymatic polymerizations in aqueous-organic mixtures have been examined. Peroxidase vigorously polymerizes a number of phenols in mixtures of water with water-miscible solvents such as dioxane, acetone, dimethylformamide, and methyl formate with the solvent content up to 95%. As a result, various phenolic polymers with average molecular weights from 400 to 2.6 x 10/sup 4/ D were obtained depending on the reaction medium composition and the nature of the phenol. Peroxidase-catalyzed copolymerization of different phenols in 85% dioxane was demonstrated. Poly(p-phenylphenol) and poly(p-cresol) were enzymatically prepared on a gram scale. They had much higher melting points, and in addition, poly(p-phenylphenol) was found to have a much higher electrical conductivity than phenol-formaldehyde resins.

  17. Quantitative characterization of interdiffusion at the resin-resin and resin-prepreg interphases of epoxy systems processed by model SQ-RTM

    OpenAIRE

    Ballout, Wael; Coulon, B.; Janssens, Y.-A.; Van Velthem, Pascal; Sclavons, Michel; Magnin, Delphine; Pardoen, Thomas; Bailly, Christian

    2016-01-01

    The interdiffusion between a low and a high viscosity epoxy resin was studied on model systems representing the novel composite manufacturing process called “Same Qualified-Resin Transfer Molding” (SQ-RTM). Neat resin model systems were first characterized after curing by Raman spectroscopy, energy dispersive X-ray microscopy, and nano-indentation, all methods reveal an interdiffusion distance of about 700–900 mm. Transmission electron microscopy further revealed a complex morphological gradi...

  18. The Effects of Doping Copper and Mesoporous Structure on Photocatalytic Properties of TiO2

    Directory of Open Access Journals (Sweden)

    Yang Wang

    2014-01-01

    Full Text Available This paper describes a system for the synthesis of Cu-doped mesoporous TiO2 nanoparticles by a hydrothermal method at relatively low temperatures. The technique used is to dope the as-prepared mesoporous TiO2 system with copper. In this method, the copper species with the form of Cu1+, which was attributed to the reduction effect of dehydroxylation and evidenced by X-ray photoelectron spectroscopy (XPS and X-ray diffraction (XRD, was well dispersed in the optimal concentration 1 wt.% Cu-doped mesoporous TiO2. In this as-prepared mesoporous TiO2 system, original particles with a size of approximately 20 nm are aggregated together to shapes of approximately 1100 nm, which resulted in the porous aggregate structure. More importantly, the enhancement of the photocatalytic activity was discussed as effects due to the formation of stable Cu(I and the mesoporous structure in the Cu-doped mesoporous TiO2. Among them, Cu-doped mesoporous TiO2 shows the highest degradation rate of methyl orange (MO. In addition, the effects of initial solution pH on degradation of MO had also been investigated. As a result, the optimum values of initial solution pH were found to be 3.

  19. Structure and Luminescence Properties of Eu3+-Doped Cubic Mesoporous Silica Thin Films

    Directory of Open Access Journals (Sweden)

    Lu Qingshan

    2010-01-01

    Full Text Available Abstract Eu3+ ions-doped cubic mesoporous silica thin films with a thickness of about 205 nm were prepared on silicon and glass substrates using triblock copolymer as a structure-directing agent using sol–gel spin-coating and calcination processes. X-ray diffraction and transmission electron microscopy analysis show that the mesoporous silica thin films have a highly ordered body-centered cubic mesoporous structure. High Eu3+ ion loading and high temperature calcination do not destroy the ordered cubic mesoporous structure of the mesoporous silica thin films. Photoluminescence spectra show two characteristic emission peaks corresponding to the transitions of5D0-7F1 and 5D0-7F2 of Eu3+ ions located in low symmetry sites in mesoporous silica thin films. With the Eu/Si molar ratio increasing to 3.41%, the luminescence intensity of the Eu3+ ions-doped mesoporous silica thin films increases linearly with increasing Eu3+ concentration.

  20. Structure and luminescence properties of eu3+-doped cubic mesoporous silica thin films.

    Science.gov (United States)

    Lu, Qingshan; Wang, Zhongying; Wang, Peiyu; Li, Jiangong

    2010-02-11

    Eu3+ ions-doped cubic mesoporous silica thin films with a thickness of about 205 nm were prepared on silicon and glass substrates using triblock copolymer as a structure-directing agent using sol-gel spin-coating and calcination processes. X-ray diffraction and transmission electron microscopy analysis show that the mesoporous silica thin films have a highly ordered body-centered cubic mesoporous structure. High Eu3+ ion loading and high temperature calcination do not destroy the ordered cubic mesoporous structure of the mesoporous silica thin films. Photoluminescence spectra show two characteristic emission peaks corresponding to the transitions of5D0-7F1 and 5D0-7F2 of Eu3+ ions located in low symmetry sites in mesoporous silica thin films. With the Eu/Si molar ratio increasing to 3.41%, the luminescence intensity of the Eu3+ ions-doped mesoporous silica thin films increases linearly with increasing Eu3+ concentration.