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Sample records for mesoporous phenol-formaldehyde resins

  1. Formulation of lignin phenol formaldehyde resins as a wood adhesive

    This work describes the potential of reducing phenol with lignin in phenol formaldehyde resin formulation. The physical and chemical properties between lignin phenol formaldehyde resin (LPF) and commercial phenol formaldehyde resin (CPF) were compared. Phenol had been replaced by lignin [that was extracted from black liquor of oil palm empty fruit bunch (EFB)] in synthesizing resin with a ratio lignin to phenol 1:1. The IR spectra showed that there were similarities in functional groups between LPF resin and CPF resin. The comparison of physical strength properties via tensile strength test between LPF resin and CPF resin showed that the newly formulated resin has higher bonding strength compared to commercial resin. Kinematics viscosity test showed that LPF resin has lower kinematics viscosity compared to CPF resin in 21 days storage time. SEM images for both resin showed similarities in the effect of resin penetration into woods vessel existed. (author)

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

    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. Wettability of Poplar Wood Impregnated by Phenol-formaldehyde Resin

    2009-01-01

    In this study,plantation poplar wood was first impregnated by low molecular weight phenol-formaldehyde(PF) resin solution by vacuum-pressure process.And then the wettability of sanded and non-sanded radial and tangential sections from un-impregnated and impregnated poplar wood was tested respectively by the measurement of contact angles using different liquids.Finally,the surface free energy of different samples was estimated by the plot extrapolation method.The results showed that the wettability of woo...

  4. Preparation of phenol formaldehyde resin from phenolated wood

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

    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.

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

    Nour Eddine El Mansouri,; Qiaolong Yuan Mail; Farong Huang

    2011-01-01

    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 ...

  7. A novel thermal degradation mechanism of phenol-formaldehyde type resins

    The thermal degradation of phenol-formaldehyde resins (PFR) was studied using thermogravimetry analysis (TG) technique. The structural changes of thermal degradation of synthetical and commercial PFR were investigated by Fourier-transform infrared rays (FTIR) and solid-state 13C nuclear magnetic resonance (13C NMR) spectroscopy. The experimental results show that the degradation of PFR can be divided into three stages. Additional cross-links are formed and small exposed groups of the cured resin are removed in the first stage. In the second stage, methylene bridges decompose into methyl groups then both phenol and cresol homolog appear. The degradation of phenol group occurs in the third stage. According to these results, a novel degradation mechanism of phenol-formaldehyde type resins is proposed: the mainly degradation process of PFR is the decomposition reaction of methylene bridges in this mechanism instead of auto-oxidation of the methylene bridges in the prevenient mechanism

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

    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. Study on Physical and Mechanical Properties of Poplar Modified by Phenol-formaldehyde Resin

    2008-01-01

    Impregnation method can effectively improve physical and mechanical properties of wood. In this study, plantation poplar lumbers are impregnated by a low molecular weight phenol-formaldehyde resin solution with concentration of 30% under vacuum-pressure process, and then dried and machined according to the related standards. The results show that the physical and mechanical properties of poplar can be improved by the treatment, except for toughness. The average density of poplar increases from 0.397 to 0.71...

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

    Wan-Chen Hsieh; Keng-Shiang Huang; Szu-Yu Chen; Chih-Yu Wang; Alexandru Mihai Grumezescu; Yung-Sheng Lin; Chin-Tung Wu; Chih-Hui Yang

    2013-01-01

    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...

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

    Noelia Álvarez-Gutiérrez; María Victoria Gil; María Martínez; Fernando Rubiera; Covadonga Pevida

    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...

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

    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.

  13. Curing reaction and mechanism of phenol-formaldehyde novolac resins for foundry

    Yan Shi

    2016-05-01

    Full Text Available In this study on the curing dynamics of phenol-formaldehyde novolac resins (PFNR and hexamethylene tetramine (HMTA, two typical commercial PFNR were selected as examples and the curing reactions of the resins with HMTA were studied by differential scanning calorimetry (DSC. Based on the data calculated by the Kissinger equation and the Crane equation, a thermocuring dynamic model was established, from which the process conditions, activation energy, reaction kinetics equation and a first-order reaction of the curing reactions were derived.

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

    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.

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

    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.

  16. Micro-structural evolution of phenol-formaldehyde resin modified by boron carbide at elevated temperatures

    The phenol-formaldehyde (PF) resin was modified by boron carbide (B4C). In order to investigate the modification effect of B4C, the residue values of pure PF resin and B4C modified PF resin were measured using thermal gravity. It was shown that the residue values of B4C modified PF resin are 71.9% and 68.4% after being pyrolyzed at 700 and 1000 deg. C, respectively, which are obviously higher than those of the pure PF resin (62.9% and 60.5% at 700 and 1000 deg. C, respectively). The microstructure evolution of the modified resin at high temperatures was also investigated by scanning electron microscopy and energy dispersive analysis of X-rays. By means of the microstructure characterization, the modification reactions between the B4C additives and the oxygen-containing volatiles, such as CO and H2O, are demonstrated. The carbon and oxygen elements remained in the resin matrix in the forms of amorphous carbon and B2O3, respectively, resulting in the improvement of residue values and stability of the PF resin at high temperatures. The distribution of modification particles became well-proportioned gradually at the elevated temperatures, and the shape of ceramic additives changed into white spherules due to the surface tension.

  17. Effect of modification with phenol formaldehyde resin on the mechanical properties of wood from Chinese fir

    Yanhui Huang

    2013-02-01

    Full Text Available Samples of Chinese fir were treated with either low-molecular-weight or commercial phenol-formaldehyde (PF resins. The macro- and micromechanical properties of the treated and untreated samples were determined. The average longitudinal tensile modulus of elasticity (MOE was 30.88% larger for the samples treated with the low-molecular-weight PF resin than it was for the untreated samples. The average MOE of the samples treated with the commercial PF resin was 29.84% less than that of the untreated samples. The micromechanical properties of the samples were investigated through nanoindentation studies. For the samples modified with low-molecular-weight PF resin, the values of average MOE and hardness were 32.94 and 32.93%, respectively, greater than those of the untreated samples. In contrast, the average MOE and hardness values were 11.99 and 18.14%, respectively, greater for the samples modified with commercial PF resin compared to the untreated samples. It could be inferred that the low-molecular-weight PF resin was able to diffuse into the nanopores in the S2 layer of the tracheid cell wall of the Chinese fir, thereby improving its macromechanical properties. Modification with low-molecular-weight PF resin was an effective way to enhance the longitudinal macromechanical properties of wood from the Chinese fir.

  18. Effect of nano BaCO3 on pyrolytic reaction of phenol-formaldehyde resin

    Zhang, Xu; Ma, Qing-zhi; Zhang, Zhong-feng; Peng, Wan-xi; Zhang, Ming-long

    2009-07-01

    Phenol-formaldehyde resin is used as the most adhesive to produce waterproof plant-based composite. However, this product contains phenol and formaldehyde which can be easily released to pollute air and water. Based on the single-factor method, the effect of nano BaCO3 on situabtion of pyrolytic reaction of PF resin was studied by Py-GC/MS. There were components including carbon dioxide, D,.alpha.-tocopherol, 1,3-bis(trimethylsilyl) benzene, phenol from PF resin in 590(see manuscript) He gas. However, the 17 compounds including phenol, 2-methyl-, phenol, carbon dioxide, p-xylene, toluene, phenol, 2-ethyl-, phenol, 2,3-dimethyl-, benzene, 1,2,3-trimethyl-, etc were identified by Py-GC/MS after PF/BaCO3 composite was pyrolyzed in 590(see manuscript) He gas, and phenol and phenol derivants were found in the compounds. The result showed that nano BaCO3 could effectively delay the pyrolysis of PF resin.

  19. Effect of phenol formaldehyde resin as vulcanizing agent on flow behavior of HDPE/PB blend

    Moayad N. Khalaf

    2014-07-01

    Full Text Available Thermoplastic elastomer (TPE based on High density polyethylene (HDPE/polybutadiene (HDPE/PB = 70/30 parts blends containing 1, 3, 5, 7 and 10 wt.% of dimethylol phenolic resin as a vulcanizing agent in the presence of SnCl2 as catalyst was prepared. The dimethylol phenolic resin was prepared in our laboratory. The blends were compounded in mixer-60 attached to a Haake rheochord meter-90. The rheological properties were measured at temperatures 140, 160, 180 and 200 °C. The linearity of the flow curve appeared for 5% of the vulcanizing agent. The shear stress and shear viscosity have increased upon increasing the shear rate over a range of loading levels of vulcanizing agent of 1%, 3%, 5%, 7% and 10%. This may be attributed to the increased vulcanization between polyethylene and the rubber blend. The flow behavior index of the system shows a pseudo plastic nature behavior (since n < 1. The consistency index (K increased with the increase in the phenol formaldehyde resin content and the temperature. Hence, the increase in the value of the consistency index (K of the polymer melts refers to more viscous materials prepared. The activation energy for the TPE blends fluctuated indicating that there is phase separation; where each polymer behaved separately. This study showed that HDPE/PB blends are characterized with good rheological properties, which can be recommended to be processed with the injection molding technique.

  20. Intrinsic fluorescence studies of compatibility in thermoplastic phenol formaldehyde resin / poly(ε-caprolactone blends

    2011-08-01

    Full Text Available Intrinsic fluorescence method was applied to study the miscibility and interactions of thermoplastic phenol formaldehyde resin (TPF / poly(ε-caprolactone (PCL blends. The characteristic intrinsic fluorescence emission of TPF at 313 nm showed the very good sensitivity to monitor the macromolecular chain motion in the TPF/PCL blends. The glass transition (Tg, crystallization (Tc, and melting transition point (Tm of TPF/PCL blends were measured by the temperature dependence of intrinsic fluorescence intensities upon heating or cooling process. Interestingly, when TPF/PCL ≥ 5/5, besides a Tg for the amorphous phase of blend, another transition at temperature a little higher than Tg of PCL can be observed by intrinsic fluorescence method. This microheterogeneity can be explained by the so-called ‘rigid amorphous phase’ (RAP due to the good flexibility and the strong self-association of PCL chains in amorphous phase. Besides, the analysis of the dependence of Tg on the content of PCL suggests that this microheterogeneity can attenuate the interactions between TPF and PCL chains and result in a lowering of Tgs of blends. In view of the simplicity and sensitivity of measurement as well as affordability of instrument, intrinsic fluorescence proved to be an effective means for characterization of microstructural variation in polymer blends.

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

    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.

  2. Synthesis of carbon-encapsulated iron carbide/iron nanoparticles from phenolic-formaldehyde resin and ferric nitrate

    Carbon-encapsulated iron carbide/iron nanoparticles have been synthesized on a large scale by the heat treatment of thermal plastic phenolic-formaldehyde resin with the aid of ferric nitrate. The effects of heating temperature on the morphologies and structures of carbonized products were investigated using transmission electron microscope, high-resolution transmission electron microscope and X-ray diffraction measurements. The products with diameter distribution of 20-100 nm consisted mainly of spheroidal nanoparticles separated by hollow onion-like carbon nanoparticles.

  3. Physico-chemical characterization of lignins from different sources for use in phenol-formaldehyde resin synthesis.

    Tejado, A; Peña, C; Labidi, J; Echeverria, J M; Mondragon, I

    2007-05-01

    During the last decades lignin has been investigated as a promising natural alternative to petrochemicals in phenol-formaldehyde (PF) resin production, due to their structural similarity. Physico-chemical characterization of three types of lignin, namely kraft pine lignin (L1), soda-anthraquinone flax lignin (L2), and ethanol-water wild tamarind lignin (L3) has been evaluated to determine which one is the most suitable chemical structure for above purpose. Characterization has been performed using Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance spectrometry ((1)H NMR) to analyse the chemical structure, gel permeation chromatography (GPC) for determining molecular weight (MW) and molecular weight distribution (MWD), differential scanning calorimetry (DSC) to measure the glass transition temperature and thermogravimetric analysis (TGA) to follow the thermal degradation. Both structural and thermal characteristics suggest that kraft pine lignin (L1) would be a better phenol (P) substitute in the synthesis of lignin-phenol-formaldehyde (LPF) resins, as it presents higher amounts of activated free ring positions, higher MW and higher thermal decomposition temperature. PMID:16843657

  4. Influence of oxidation on the preparation of porous carbons from phenol-formaldehyde resins with KOH activation

    Teng, H.; Wang, S.C.

    2000-03-01

    The influence of oxidation on the production of high-porosity carbons from phenol-formaldehyde resins with KOH activation were examined under various preparation conditions. The activation process principally consisted of KOH impregnation followed by carbonization. Experimental results showed that prior to carbonization treating the resins with oxygen at 120 C, either before or after KOH impregnation, enabled the enhancement of the yield of the carbon products. The porosity development was found to be hindered by conducting oxidation prior to the impregnation. For oxidation performed after the impregnation, at a low KOH/resin ratio the porosity was found to decrease upon oxidation, whereas the oxidation enhanced porosity development for activation performed at higher ratios. Varying the carbonization temperature and time did not show obvious influence on the effects of the oxidation.

  5. Expansive failure reactions and their prevention in the encapsulation of phenol formaldehyde type ion exchange resins in cement based systems

    Lewatit DN is a phenol formaldehyde based ion exchange resin used to remove radioactive caesium from liquid waste streams such as fuel cooling ponds and effluents. This paper presents the results of a study of the encapsulation of the bead form of the resin in cement with particular reference to the mechanisms of its interaction with the encapsulant. When incorporated in pure ordinary Portland cement (OPC) at loadings in excess of 15 wt % an unstable product results due to expansion of the systems and at higher waste loadings failure results after only a few days. Evidence from differential scanning calorimetry, X-ray diffraction and scanning electron microscopy all indicate the cause of the expansive reaction to be the formation of crystals of calcium salts around and within the resin beads. Addition of BFS and sodium hydroxide prevent the formation of these salts by removal of calcium hydroxide from the system in other reactions. (author)

  6. USE OF LIGNIN SEPARATED FROM BIO-OIL IN ORIENTED STRAND BOARD BINDER PHENOL-FORMALDEHYDE RESINS

    Badamkhand Sukhbaatar

    2009-05-01

    Full Text Available Bio-oil produced from fast pyrolysis of biomass has been investigated as a renewable fuel and as a source of industrial chemicals. The lignin fraction of bio-oil produced from wood in our fast pyrolysis reactor was separated by using only water and methanol with a 25% yield based on bio-oil weight. This separation procedure appears to be of lower cost than the reported extraction procedure using ethyl acetate as solvent. The isolated pyrolytic lignin was smoothly incorporated into phenol-formaldehyde resins at 30%, 40%, and 50% phenol replacement levels, and the resultant resins were evaluated as oriented strand board core-layer binders. The evaluation results indicated that the pyrolytic lignin is effective for up to about 40% replacement of phenol in synthesizing wood adhesive type PF resins.

  7. Study on the structural evolution of modified phenol-formaldehyde resin adhesive for the high-temperature bonding of graphite

    A novel adhesive for carbon materials composed of phenol-formaldehyde resin, boron carbide and fumed silica, was prepared. The adhesive property of graphite joints bonded by the above adhesive treated at high-temperatures was tested. Results showed that the adhesive was found to have outstanding high-temperature bonding properties for graphite. The adhesive structure was dense and uniform even after the graphite joints were heat-treated at 1500 deg. C. Bonding strength was 17.1 MPa. The evolution of adhesive structure was investigated. The results indicated that the addition of the secondary additive, fumed silica, improved the bonding performance greatly. Borosilicate phase with better stability was formed during the heat-treatment process, and the volume shrinkage was restrained effectively, which was responsible for the satisfactory high-temperature bonding performance of graphite

  8. Synthesis of Phenol-Formaldehyde Resin Modified with Epoxy Resin%环氧改性酚醛树脂的合成与研究

    杜郢; 周太炎; 王哲; 任筱芳; 蔡晓燕

    2012-01-01

    合成了酚醛树脂胶黏剂,并采用环氧树脂和有机硅对其进行改性,考察了环氧树脂的加入阶段、种类和加入量及有机硅加入量对酚醛树脂胶黏剂性能的影响;采用TG-DSC和FTIR等方法对试样进行了表征.实验结果表明,在回流前加入约1.5%(w)(基于体系质量)的双酚A型环氧树脂E51和约0.6%(w)(基于体系质量)的羟丙基聚二甲基硅氧烷(有机硅8427),所得酚醛树脂胶黏剂的黏度适中、柔韧性较好,游离甲醛含量为0.037% (w),拉伸剪切强度达到7.1 MPa,各项指标均超过国家标准;改性后的酚醛树脂胶黏剂的耐热性和柔韧性较改性前均有明显提高.%A phenol-formaldehyde resin adhesive was synthetized and modified with epoxy resin and organo-silicon. The effects of adding stage, species and dosage of epoxy resin and organo-silicon dosage on the properties of the phenol-formaldehyde resin adhesives were studied. The products were characterized by means of FTIR and TG-DSC. The results showed that the phenol-formaldehyde resin adhesive modified with about 1.5%(w) (based on the mass of system) bisphenol A epoxy resin(E51) and about 0.6%(w) (based on the mass of system) hydroxypropyl polydimethylsiloxane(organo-silicon 8427) before reflux had modest viscosity and good flexibility, with 0.037%(w) formaldehyde and 7.1 MPa tensile shear strength. The flexibility and thermal resistance of the modified phenol-formaldehyde resin adhesive are better than those of unmodified one.

  9. SYNTHESES AND ADSORPTION PROPERTIES OF PHENOL-FORMALDEHYDE TYPE CHELATING RESINS BEARING THE FUNCTIONAL GROUP OF TARTARIC ACID

    Rong-jun Qu; Chun-nuan Ji; Yan-zhi Sun; Zhong-fang Li; Guo-xiang Cheng; Ren-feng Song

    2004-01-01

    Several kinds of novel chelating resins bearing the functional group of tartaric acid (TTA-FQ-12, TTA-FQ-23, and TTA-FQ-34) were synthesized by reacting epoxy maleic anhydride, which was prepared through the oxidization reaction of maleic anhydride by hydrogen peroxide, with phenol-formaldehyde resin containing polyamine (FQ resins series). The effects of such factors as reaction time, reaction temperature and pH value on the loading capacity of TTA in resins were investigated. The results showed that the optimum reaction conditions are as follows: time 9-12 h; temperature 90-105℃;pH value 6-10. The loading capacities of TTA can reach 0.15, 0.14, and 0.11 mmol/g-1 when the functional group of FQ resin was -OCH2CH2NHC2H4NH2, -O(CH2CH2NH)2C2H4NH2 and -O(CH2CH2NH)3C2H4NH2), respectively. The structures of resins were characterized by FTIR spectra. The primary study on the adsorption properties of the resins for metal ions showed that there are two kinds of adsorption mechanisms i.e. ion exchange and chelate in the adsorption process.TTA-FQ resins have much higher adsorption selectivity for Pb2+and Zn2+ than for Cu2+ and Ni2+. These resins can probably be used for separating Pb2+ or Zn2+ in the mixture of metal ions or for treating wastewater containing heavy metal ions.

  10. [Modified Mechanism of Cell Walls from Chinese Fir Treated with Low-Molecular-Weight Phenol Formaldehyde Resin].

    Huang, Yan-hui; Fei, Ben-hua; Zhao, Rong-jun

    2015-12-01

    Study on the modified mechanism of wood cell walls, it is very important for improving treatment reagents, optimizing treatment technology, and enhancing wood density, mechanical properties, dimensional stability, and so on. Samples of plantation Chinese fir were treated gradually with synthesized water-soluble low-molecular-weight phenol formaldehyde (PF) resins under vacuum and pressure. The correlated physical and chemical properties of the treated and untreated reference samples were determined by X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FTIR), and nuclear magnetic resonance spectrometer(NMR) (Using method of Cross Polarization/Magic Angle Spinning for continuous testing) with high precision and resolution. The results showed that, after treated with water-soluble low-molecular-weight PF resin, the average values of crystallinity from the treated samples were decreased obviously, and the average reduction rate was 12.67%, 11.91% and 6.26%, respectively. Comparing water-soluble, low-molecular-weight PF resin modified Chinese fir with untreated reference samples, no new chemical shifts and characteristic peaks of functional groups from esters, ethers, etc. were present by using FTIR and ¹³C NMR spectrum. It was considered that there was no distinct chemical reaction between the water-soluble low-molecular-weight PF resin and Chinese Fir cell walls. But water-soluble low-molecular-weight PF resin could enter into the structure relatively loose, large size spaces, relatively area large amorphous regions in cell walls of Chinese fir tracheids, and form physical filling, which resulting in the decreasing of relative crystallinity. This study has important reference value for the development of new wood modification reagents and the optimization of wood modification process. The findings also provide important theoretical foundation for further proving the modification mechanisms of wood cell walls and enriching the modified theories of

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

    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.

  12. Zinc isotope separation by phenol formaldehyde type 15-crown-5 resin in organic solvents

    Zinc adsorption and isotope separation by newly synthesized benzo-15-crown-5 resin was evaluated using various solvents. This resin was synthesized in the pores of silica beads for chromatography use. Larger adsorption of zinc was obtained in the case of acetic acid derivatives than in protic solvent such as water and alcohol by the batch treatment. The displacement chromatography was conducted to study zinc isotope separation. The isotope separation coefficient ε=0.32x10-3, 0.69x10-3 and HETP=0.2268, 0.3968 cm were determined for isotopic pair of 68Zn/64Zn at 25degC by five meters migration experiment using methyl isobutyl ketone and acetic acid, respectively. The improvement of enrichment ratio is very small between 1 and 5 m migration. Hydrogen chloride and/or water obviously reduce zinc adsorption to this resin. (author)

  13. Production of plywood panels from Pinus taeda using veneers of differing densities and phenol-formaldehyde resin with high and low molecular weights

    Graciela Ines Bolzon de Muniz

    2013-06-01

    Full Text Available This study aimed to evaluate the bonding quality of plywood panels from Pinus taeda using low and high molecular weight phenol-formaldehyde resin and veneers from three different density classes. The experiment consisted of six treatments, each of which produced three panels (replicates. Tests were conducted to evaluate glue line strength to shear stress after two boiling cycles and after 24 hours of cold water immersion. Also determined was the percentage of defects in wood samples. Results indicated that the density classes being assessed differed statistically. However, no significant difference was found between panels produced with high and panels produced with low molecular weight resin as to the mean values of glue line strength, whether subjecting them to two boiling cycles or after 24 hours of cold water immersion. Interactions between different density classes and adhesive formulations were found not significant either. Low molecular weight resin (BPM and panels produced with higher density veneers were found to have better behavior, regarding both bonding strength and percentage of defects. It was concluded that the bonding quality of plywood panels from Pinus taeda was satisfactory after using different densities of veneer and also high and low molecular weight phenolic resins. All treatments were found to comply with minimum requirements established in European standard EN 314-1/1993, which addresses bonding quality of plywood panels.

  14. Microwave Assisted Synthesis of Phenol-Formaldehyde Resole

    Subhash Chandra Bajia; Pawan Swarnkar; Sudesh Kumar; Birbal Bajia

    2007-01-01

    An efficient synthesis of phenol-formaldehyde resin has been achieved by using conventional as well as microwave irradiation. Resin samples were tested for their physical and chemical properties. The structures of the resins have been supported by their spectral analysis.

  15. Investigation of the Wood/Phenol-Formaldehyde Adhesive Interphase Morphology

    Laborie, Marie-Pierre Genevieve

    2002-01-01

    This work addresses the morphology of the wood/ Phenol-Formaldehyde (PF) adhesive interphase using yellow-poplar. In this case, morphology refers to the scale or dimension of adhesive penetration into wood. The objective is to develop methods for revealing ever smaller levels of wood/resin morphology. Dynamic techniques that are commonly utilized in polymer blend studies are investigated as potential methods for probing the wood/ adhesive interphase morphology. These are Dynamic Mechanica...

  16. 液相色谱-质谱联用技术分析环氧大豆油改性PF结构%Structure Analysis of Epoxidized Soybean Oil Modiifed Phenol Formaldehyde Resin with Liquid Chromatography-Mass Spectrometry Technology

    赵彦芝; 周菊英; 李浩; 于畅

    2014-01-01

    Under the conditions of acid catalysis or alkaline catalysis,the epoxidized soybean oil modified phenolic compounds was synthesized by using epoxidized soybean oil to react with phenol and bisphenol A,then acid catalytic or alkaline catalytic epoxidized soybean oil modified phenol formaldehyde resin (PF) was prepared through the reaction of the compounds and formaldehyde solution. The compounds were analyzed by the liquid phase chromatography-mass spectrometry technology. From the analysis results,it is gained that phenol and bisphenol A all react with epoxidized soybean oil under the conditions of acid catalysis but bisphenol A is more easy to react with epoxidized soybean oil under the conditions of alkaline catalysis. FTIR analysis results show that the compounds synthesized under the two catalysis conditions all can react with formaldehyde for shaping epoxidized soybean oil modified PF with the body conformation. Comparing with acid catalytic epoxidized soybean oil modified PF,the heat resistance of the alkaline catalytic epoxidized soybean oil modified PF is better and the tensile strength is higher.%在酸性或碱性催化条件下,先将环氧大豆油与苯酚及双酚A反应,合成环氧大豆油改性酚类产物,然后将该产物与甲醛水溶液反应制备了酸催化或碱催化环氧大豆油改性酚醛树脂(PF)。利用液相色谱-质谱联用技术对合成的环氧大豆油改性酚类产物进行分析,发现在酸性催化条件下苯酚和双酚A均与环氧大豆油发生了反应,在碱性催化条件下双酚A更易与环氧大豆油发生反应。傅立叶变换红外光谱分析结果表明,两种催化条件下合成的环氧大豆油改性酚类产物均可与甲醛反应生成具有体型结构的环氧大豆油改性PF。相对于酸催化环氧大豆油改性PF,碱催化的耐热性更好,拉伸强度更高。

  17. Structure and distribution of cross-links in boron-modified phenol-formaldehyde resins designed for soft magnetic composites: a multiple-quantum 11B-11B MAS NMR correlation spectroscopy study

    Kobera, Libor; Czernek, Jiří; Strečková, M.; Urbanová, Martina; Abbrent, Sabina; Brus, Jiří

    2015-01-01

    Roč. 48, č. 14 (2015), s. 4874-4881. ISSN 0024-9297 R&D Projects: GA MŠk(CZ) LD14010 Grant ostatní: European Commission(XE) COST Action MP1202 HINT Institutional support: RVO:61389013 Keywords : phenol-formaldehyde polymers * boron crosslinks * soft magnetic composites Subject RIV: CD - Macromolecular Chemistry Impact factor: 5.800, year: 2014

  18. Properties of Modified Phenol-Formaldehyde Adhesive for Plywood Panels Manufactured from High Moisture Content Veneer

    Pavlo Bekhta; Galyna Ortynska; Jan Sedliacik

    2015-01-01

    This paper presents the results of laboratory investigations of bonding high moisture content (15 %) birch veneers (Betula pubescens Ehrh.) with the use of modifi ed phenol-formaldehyde (PF) resin. Wheat starch, rye flour, resorcinol and phenol-resorcinol-formaldehyde resin were chosen as modifying agents. Dynamic viscosity, hydrogen ions concentration, solid content, curing time, pot life of developed adhesive compositions and shear strength of plywood samples were evaluated. ANOVA analysis ...

  19. 不同固含量低分子酚醛树脂浸渍改性杉木板材性能的研究%The Effects of Phenol Formaldehyde Resin Impregnation on the Main Physical and Mechanical Properties of Cunninghamia lanceolata Lumber

    王向歌; 金菊婉; 邓玉和; 韩书广; 庄寿增

    2014-01-01

    To improve the physical and mechanical properties of Cunninghamia lanceolata wood lumber,low molecular weight phenol formaldehyde resin was impregnated into the lumber via a “vacuum-pressure”process. The distribution characteristic of resin was investigated in the length and thickness directions.The results showed that the dimensional stability of Cunninghamia lanceolata had increased gradually after impregnating with the 10%, 20%,30% concentrations of PF resin.The modulus of rupture remained unchanged after it increased from 64.5 MPa to 75 .0 MPa.The modulus of elasticity and hardness were increased by 6.1%,27.5%,48.2% and 29.8%、63.1%,73.8%,respectively.However,the impact toughness of Cunninghamia lanceolata decreased gradually with the increase of weight gain rate of resin.In the length direction,the resin distributes uniformly.In the thickness direction,the content of resin in the edge is more than that in the inside.%为改善杉木的物理力学性能,采用真空-加压浸渍工艺,对速生杉木进行低分子酚醛树脂增强改性处理,分析不同树脂增重率对改性杉木性能的影响,以及树脂在木材长度和厚度方向上的分布特点。结果表明,杉木经过固含量为10%、20%、30%的酚醛树脂浸渍处理后,其尺寸稳定性随树脂固含量的增加逐渐提高,静曲强度由64.5 MPa提高至75.0 MPa,弹性模量和表面硬度分别提高了6.1%、27.5%、48.2%和29.8%、63.1%、73.8%,但冲击韧性随着树脂增重率的增加而逐渐降低;树脂在木材长度方向上分布均匀,在厚度方向上木材表面多于其内部。

  20. Properties of Modified Phenol-Formaldehyde Adhesive for Plywood Panels Manufactured from High Moisture Content Veneer

    Pavlo Bekhta

    2015-01-01

    Full Text Available This paper presents the results of laboratory investigations of bonding high moisture content (15 % birch veneers (Betula pubescens Ehrh. with the use of modifi ed phenol-formaldehyde (PF resin. Wheat starch, rye flour, resorcinol and phenol-resorcinol-formaldehyde resin were chosen as modifying agents. Dynamic viscosity, hydrogen ions concentration, solid content, curing time, pot life of developed adhesive compositions and shear strength of plywood samples were evaluated. ANOVA analysis has shown that type, mixture and content of modifying agents affect significantly the mechanical performance of plywood panels. The obtained results of shear strength values were above the standard requirements (1 N/mm2, and the properties of samples met the European standard EN 314-2 for gluing quality of class 3 and such plywood panels can be used in exterior conditions.

  1. Biodegradation of polystyrene, poly(metnyl methacrylate), and phenol formaldehyde.

    Kaplan, D L; Hartenstein, R; Sutter, J

    1979-01-01

    The biodegradation of three synthetic 14C-labeled polymers, poly(methyl methacrylate), phenol formaldehyde, and polystyrene, was studied with 17 species of fungi in axenic cultures, five groups of soil invertebrates, and a variety of mixed microbial communities including sludges, soils, manures, garbages, and decaying plastics. Extremely low decomposition rates were found. The addition of cellulose and mineral failed to increase decomposition rates significantly. PMID:533278

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

    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. PMID:19854642

  3. 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

    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.

  4. Synthesis of white light emitting mesoporous carbon-silica nanocomposite

    Sato, Koji; Ishikawa, Yukari [Japan Fine Ceramics Center, Atsuta-ku Nagoya 456-8587 (Japan); Matsumura, Akihiro [Department of Frontier Materials, Showa-ku Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Ishii, Yosuke; Kawasaki, Shinji, E-mail: kosato@jfcc.or.jp, E-mail: yukari@jfcc.or.jp [Department of Materials Science and Engineering, Showa-ku Nagoya Institute of Technology, Nagoya 466-8555 (Japan)

    2011-05-15

    White light emitting mesoporous carbon-silica (MPCS) was synthesized by serially adding triblock copolymer (Pluronic, F127), ethanol (EtOH), tetraethoxysilane (TEOS), hydrochloric acid aqueous (HCl) and phenol-formaldehyde resin (resol) followed by the heat treatments of carbonization and oxidation. The PL intensity of MPCS showed a tendency to be strong with increasing of HCl concentration in {>=} 0.2 M. The pore size of MPCS that emits white light was 8 {approx} 9 nm and the specific surface area was 320 {approx} 418 m{sup 2} / g.

  5. Synthesis of white light emitting mesoporous carbon-silica nanocomposite

    Sato, Koji; Ishikawa, Yukari; Matsumura, Akihiro; Ishii, Yosuke; Kawasaki, Shinji

    2011-05-01

    White light emitting mesoporous carbon-silica (MPCS) was synthesized by serially adding triblock copolymer (Pluronic, F127), ethanol (EtOH), tetraethoxysilane (TEOS), hydrochloric acid aqueous (HCl) and phenol-formaldehyde resin (resol) followed by the heat treatments of carbonization and oxidation. The PL intensity of MPCS showed a tendency to be strong with increasing of HCl concentration in >= 0.2 M. The pore size of MPCS that emits white light was 8 ~ 9 nm and the specific surface area was 320 ~ 418 m2 / g.

  6. Radiation-chemical hardening of phenol-formaldehyde oligomers

    Radiation-chemical hardening of phenol formaldehyde oligomers of the resol type has been studied in the presence of furfural and diallylphthalate diluents. The samples have been hardened on an electron accelerator at an electron energy of 1.0-1.1 MeV and a dose rate of 2-3 Mrad/s. The kinetics of hardening has been studied on the yield of gel fraction within the range of absorbed doses from 7 to 400 Mrad. Radiation-chemical hardening of the studied compositions is activated with sensitizers, namely, amines, metal chlorides, and heterocyclic derivatives of metals. Furfural and diallylphthalate compositions are suitable for forming glass-fibre plastic items by the wet method and coatings under the action of ionizing radiations

  7. Demethylation of Wheat Straw Alkali Lignin for Application in Phenol Formaldehyde Adhesives

    Yan Song

    2016-05-01

    Full Text Available Lignin is a natural biopolymer with a complex three-dimensional network. It is the second most abundant natural polymer on earth. Commercially, lignin is largely obtained from the waste liquors of pulping and bioethanol productions. In this study, wheat straw alkali lignin (WSAL was demethylated by using an in-situ generated Lewis acid under an optimized demethylation process. The demethylation process was monitored by a semi-quantitative Fourier Transform Infrared Spectroscopy (FTIR method. The demethylated wheat straw alkali lignin (D-WSAL was further characterized by Proton Nuclear Magnetic Resonance (1H NMR, Gel Permeation Chromatography (GPC, and titration methods. After the demethylation process, it was found that the relative value of the methoxy group decreased significantly from 0.82 to 0.17 and the phenolic hydroxyl group increased from 5.2% to 16.0%. Meanwhile, the hydroxyl content increased from 6.6% to 10.3%. GPC results suggested that the weighted averaged molecular weight of D-WSAL was lower than that of WSAL with a smaller polydispersity index. The D-WSAL was then used to replace 60 wt % of phenol to prepare lignin-based phenol formaldehyde adhesives (D-LPF. It was found that both the free formaldehyde content and the free phenol content in D-LPF were less than those of the lignin-based phenol formaldehyde adhesives without lignin demethylation (LPF. Gel time of D-LPF was shortened. Furthermore, the wet and dry bonding strengths of lap shear wood samples bonded using D-LPF were higher than those of the samples bonded using LPF. Therefore, D-WSAL has shown good potential for application in phenol formaldehyde adhesives.

  8. Peculiarities of coalescence during extraction of scandium by phenol formaldehyde oligomer from sulfate solutions

    Different types of coalescence in extraction system of 0.5 M solution of phenol formaldehyde oligomer in toluene - aqueous scandium sulfuric acid solutions are detected and studied. Condition under the which scandium is extracted in organic phase completely within 30 second are established. Extraction and reextraction of scandium in the cases of different duration of phase contact are investigated. Reproducible regularities of changes of light scattering of extracts and pH values of raffinates in different conditions are revealed. Empirical equation describing coalescence for one of the considered case is presented

  9. Hydrothermal degradation of lignin: products analysis for phenol formaldehyde adhesive synthesis.

    Yang, Sheng; Yuan, Tong-Qi; Li, Ming-Fei; Sun, Run-Cang

    2015-01-01

    Corncob lignin was treated with pressurized hot water in a cylindrical autoclave in current investigation. With the aim of investigating the effect of reaction temperature and retention time on the distribution of degradation products, the products were divided into five fractions including gas, volatile organic compounds, water-soluble oil, heavy oil, and solid residue. It was found that hydrothermal degradation of corncob lignin in pressurized hot water produced a large amount of phenolic compounds with lower molecular weight than the raw lignin. Some phenolic and benzene derivatives monomers such as vanillin, 2-methoxy-phenol, 2-ethyl-phenol, p-xylene, and 1, 3-dimethyl-benzene were also identified in the degradation products. The products were further analyzed by GC-MS, GPC, 2D-HSQC, and (31)P-NMR to investigate their suitability for partial incorporation into phenol formaldehyde adhesive as a substitution of phenol. The results indicated that the reaction temperature had more effect on the products distribution than the retention time. The optimal condition for heavy oil production appeared at 290 °C with retention time 0 min. The compounds of heavy oil had more active sites than the raw lignin, suggesting that the heavy oil obtained from hydrothermal degradation of lignin is a promising material for phenol formaldehyde adhesive synthesis. PMID:25109457

  10. Relation between Mechanical Properties and Pyrolysis Temperature of Phenol Formaldehyde Resin for Gas Separation Membranes

    Šupová, Monika; Svítilová, Jaroslava; Chlup, Zdeněk; Černý, Martin; Weishauptová, Zuzana; Suchý, Tomáš; Machovič, Vladimír; Sucharda, Zbyněk; Žaloudková, Margit

    2012-01-01

    Roč. 56, č. 1 (2012), s. 40-49. ISSN 0862-5468 R&D Projects: GA ČR GA203/09/1327 Institutional research plan: CEZ:AV0Z30460519; CEZ:AV0Z20410507 Keywords : glassy carbon * membranes * mechanical properties Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.418, year: 2012 http://www. ceramics -silikaty.cz/2012/pdf/2012_01_40.pdf

  11. Stabilizing diamond surface conductivity by phenol-formaldehyde and acrylate resins

    Rezek, Bohuslav; Kozak, Halyna; Kromka, Alexander

    2009-01-01

    Roč. 517, č. 13 (2009), s. 3738-3741. ISSN 0040-6090 R&D Projects: GA AV ČR KAN400100701; GA MŠk LC510 Institutional research plan: CEZ:AV0Z10100521 Keywords : diamond * surface conductivity * polymer * passivation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.727, year: 2009

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

    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+ g−1) or chlorosulphonic acid (1.31 mmol H+ g−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 of leaching resistance

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

    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

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

    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.

  15. The influence of the diluent nature on scandium extraction by the phenol-formaldehyde resol oligomer yarrezin B

    The paper studies the effect of diluent nature on scandium extraction by Yarrezin B phenol-formaldehyde resol oligomer using n-octan, toluene, chloroform, n-octanol and kerosene as an example. Correlation coefficients of dependences of scandium distribution factor on some parameters of diluents are calculated. Possibility to use some parameters of diluents to predict their effect on extraction indices is determined. Hildebrandt solubility parameter of extracting agent and parameters of extracting agent-diluent interaction according to Flory-Haggins are calculated. 13 refs., 2 figs., 4 tabs

  16. Investigation of utilization of process of polyethylene waste of low density for creation of competitive materials with application of phenol formaldehyde oligomers

    Full text: The possibility of the utilization of low density polyethylene wastes by means of their modification with phenol formaldehyde oligomers (Ph FO) and PhFO with the thiourathenes has been investigation. Theology properties of the investigated systems showed that the obtained compositions can be able to be processed by the ordinary methods such as extrusion and casting

  17. Effects of press pressures on glue line thickness and properties of laminated veneer lumber glued with phenol formaldehyde adhesive

    Ramazan Kurt

    2012-11-01

    Full Text Available The effects of press pressure on glue line thickness (GLT and properties of laminated veneer lumbers (LVLs manufactured from half-round sliced I-214 hybrid poplar clone veneers with phenol formaldehyde adhesives were determined. The results showed that press pressures significantly influenced GLT and properties of LVLs. Results of higher specific gravity, thickness swelling ratio, and mechanical properties, but lower GLT and water absorption ratio were attributed to higher press pressure uses. Optimum properties were obtained by using a press pressure of 10 kg cm-2 in relation to GLT and properties of LVLs. Significant relationships were found between GLT and mechanical properties. GLT may provide reliable information to determine wood bonding quality and may be used for non-destructive evaluation of mechanical properties of wood composites in the future.

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

    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. USE OF LIGNIN SEPARATED FROM BIO-OIL IN ORIENTED STRAND BOARD BINDER PHENOL-FORMALDEHYDE RESINS

    Badamkhand Sukhbaatar; Philip H. Steele; Moon G. Kim

    2009-01-01

    Bio-oil produced from fast pyrolysis of biomass has been investigated as a renewable fuel and as a source of industrial chemicals. The lignin fraction of bio-oil produced from wood in our fast pyrolysis reactor was separated by using only water and methanol with a 25% yield based on bio-oil weight. This separation procedure appears to be of lower cost than the reported extraction procedure using ethyl acetate as solvent. The isolated pyrolytic lignin was smoothly incorporated into phenol-for...

  20. Characterization of alkaline lignins for use in penol-formaldehyde and epoxy resins

    El Mansouri, Nour-Eddine; Yuan, Qiaolong; Huang, Farong

    2011-01-01

    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 ...

  1. Obtaining and characterization of composite material base on ablative phenolic resin and carbon fibers

    Srebrenkoska, Vineta

    2002-01-01

    In this master paper is optimized a technological treatment for production of a molding compound based on short carbon fibers and ablative phenol- formaldehyde resin for high temperature application. The characterization of the starting raw materials is performed and molding compounds with different fiber/matrix ratio and different fiber length are obtained. From the different lab-samples molded parts are made by thermocompression. All physical, mechanical and thermal properties of the co...

  2. Chemical derivation to enhance the chemical/oxidative stability of resorcinol-formaldehyde (R-F) resin

    Hubler, T.L.; Shaw, W.J.; Brown, G.N.; Linehan, J.C.; Franz, J.A.; Hart, T.R.; Hogan, M.O.

    1996-09-01

    Tank wastes at Hanford and SRS contain highly alkaline supernate solutions of conc. Na, K nitrates with large amounts of {sup 137}Cs. It is desirable to remove and concentrate the highly radioactive fraction for vitrification. One candidate ion exchange material for removing the radiocesium is R-F resin. This report summarizes studies into synthesis and characterization of 4-derivatized R-F resins prepared in pursuit of more chemically/oxidatively robust resin. 85% 4-fluororesorcinol/15% phenol formaldehyde resin appears to have good stability in alkaline solution, although there may be some nucleophilic displacement reaction during synthesis; further studies are needed.

  3. Chemical derivation to enhance the chemical/oxidative stability of resorcinol-formaldehyde (R-F) resin

    Tank wastes at Hanford and SRS contain highly alkaline supernate solutions of conc. Na, K nitrates with large amounts of 137Cs. It is desirable to remove and concentrate the highly radioactive fraction for vitrification. One candidate ion exchange material for removing the radiocesium is R-F resin. This report summarizes studies into synthesis and characterization of 4-derivatized R-F resins prepared in pursuit of more chemically/oxidatively robust resin. 85% 4-fluororesorcinol/15% phenol formaldehyde resin appears to have good stability in alkaline solution, although there may be some nucleophilic displacement reaction during synthesis; further studies are needed

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

    Zhao Yi; Jizhi Zhang; Shifeng Zhang; Qiang Gao,; Jianzhang Li; Wei Zhang

    2016-01-01

    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(OH)2), sodium carbonate (Na2CO3), lithium hydroxide (LiOH), and zinc acetate ((CH3COO)2Zn). The cure-acceleration effects of these catalysts on the prop...

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

    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 in an.......2%) reacted to PFR-2. Of those 28 individuals, one had a positive reaction to formaldehyde and 2 to p-tertiary-butylphenol-formaldehyde resin. Simultaneous allergic reactions were noted to colophonium in 3, to Myroxylon pereirae in 5, and to fragrance mix I in 8. Conclusions The contact allergy frequency in...

  6. Catalytic Graphitization of Phenolic Resin

    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.

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

    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.

  8. Cardanol Modified Phenol-Formaldehyde Resin of the UV Curing Research%腰果酚改性酚醛树脂的UV光固化研究

    云智勉; 尹美娟; 周亮

    2009-01-01

    合成了腰果酚改性酚醛树脂,得到了优化反应时间为4 h,催化剂的用量为1.2%~1.4%(质量百分比).研究了涂膜紫外光固化的过程,实验结果表明:UV固化膜的物理性能优于热固化膜.

  9. EPICOR-II resin degradation results from first resin samples of PF-8 and PF-20

    The 28 March 1979 accident at Three Mile Island Unit 2 released approximately 560,000 gallons of contaminated water to the Auxiliary and Fuel Handling Buildings. The water was decontaminated using a demineralization system called EPICOR-II developed by Epicor, Inc. The Low-Level Waste Data Base Development - EPICOR-II Resin/Liner Investigation Project is studying the chemical and physical conditions of the synthetic ion exchange resins found in several EPICOR-II prefilters. This report summarizes results and analyses of the first sampling of ion exchange resins from EPICOR-II prefilters PE-8 and -20. Results are compared with baseline data from tests performed on unirradiated Epicor, Inc. resins to determine if degradation has occurred due to the high internal radiation dose received by the EPICOR-II resins. Results also are compared with recent findings on resin degradation by Battelle Columbus Laboratories and Brookhaven National Laboratory. Analyses comparing test results of resins from EPICOR-II prefilters PF-8 and -20 with unirradiated resins obtained from Epicor, Inc. show resin degradation has occurred in some of the EPICOR-II resins examined. The mechanism of degradation is compared with work of other researchers and is consistent with their findings. The strong acid cation resins (divinylbenzene, styrene base structure) are losing effective cross-linking along with scission of functional groups and are experiencing first an increase and eventually a decrease in total exchange capacity as the absorbed radiation dose increases. The phenolic cation resins (phenol-formaldehyde base structure) show a loss of effective cross-linking and oxidation of the polymer chain. Analyses of resins removed from EPICOR-II prefilters PF-8 and -20 over the next several years should show a further increase in degradation

  10. Weather ability studies of phenolic resin coated woods and glass fiber reinforced laminates

    Phenolic resins have made a major breakthrough in the field of high technology in 80's. These are now active participants of high tech' areas ranging from electronics, computers, communication, outer space, aerospace, advanced materials, bio materials and technology. A phenol - formaldehyde (1:1.5) resin having resin content of 70% synthesized in the laboratory has been applied for wood coating and reinforcing glass fiber. The weatherability and solvent resistance of these items have been studied and results discussed keeping in view the envisaged application for structural materials and chemical equipment. The toxic materials released during contact with solvents for chemical applications and during degradation general have been monitored. The results are discussed with reference to environmental pollution due to these resins and their composites under different conditions. (authors)

  11. Research Progress in the Modified Three Formaldehyde Resins%改性三醛胶的研究进展

    常蔓丽

    2011-01-01

    This paper overviewed the domestic research status of wood adhesive. The characteristics of urea formaldehyde resin, melamine resin and phenol formaldehyde resin were introduced in detail. Meanwile, the research progress of the the modified three formaldehyde resins was expounded. Moreover, existing problem and developing trend of the three formaldehyde resins in wood machining field in our country were indicated.%综述木材胶粘剂的国内现状,介绍了脲醛胶、三聚氰胺一甲醛胶、酚醛胶传统胶种的性质及其低醛改性研究进展,指出了我国木材加工领域用三醛胶存在的问题和发展趋势.

  12. Influence of structure of a crosslinked epoxy resin on its properties studied by positron annihilation and other methods

    Positron annihilation has been applied to study samples of two crosslinked epoxy resins: diglycidyl ether of bisphenol A (Epikote 828) and polyglycidyl-ether of phenol-formaldehyde novolac (Epikote 155) cured with 4,4'-diamino-diphenylo-methane (MDA), phenol-formaldehyde novolac resin (Novolac Z) and bisphenol A (formaldehyde resin). Results of measurements of positron lifetime spectra were compared with the ones coming from DMTA, flexural strength testing and density measurements. The most important features of samples (glass transition temperature, storage modulus, flexural strength, crosslinking density and tan δ) proved to be correlated with the product Ι3 x v-bar, proportional to the fractional free volume in samples. Values of v-bar have been estimated from the values of τ3, the longest lifetime in positron lifetime spectra. Ι3 corresponds to the intensity of the longest-lived component in them. Distributions of free volume radii reconstructed in the basis of PAL measurements are given for all samples. The influences of structure of both cured resin and the curing agent on the properties of the crosslinked products is clearly seen from the presented results. (author)

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

    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.

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

    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.

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

    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)

  16. 腰果酚醛树脂嵌段聚醚的合成及其破乳性能研究%Synthesis and demulsification of cardanol based phenol-formaldehyde resin block polyether

    王俊; 高振宇; 张志秋; 吴松; 李翠勤

    2014-01-01

    以腰果酚和甲醛为原料合成一种起始剂——腰果酚醛树脂,再以起始剂为原料,分别与环氧丙烷(PO)和环氧乙烷(EO)进行加成聚合,合成了一种腰果酚醛树脂嵌段聚醚(CPFE).采用FT IR对CPFE的分子结构进行了表征,通过瓶试法初步研究了CPFE作为破乳剂对大庆油田采出液的破乳性能.实验结果表明,所合成的CPFE对O/w型原油乳液具有良好的破乳性能,随着添加量和破乳温度的增加,脱水率增大,所表现出来的影响规律与常规聚醚型破乳剂是一致的.在破乳温度为45℃,CPFE的添加量为250 mg/L时,30 min的脱水率达到97.8%,腰果酚醛树脂嵌段聚醚具有快速脱水的特征,显示出良好的应用前景.

  17. Effect of Phenol-Formaldehyde Resin Modified on Properties of Ochroma Lagopus Wood%酚醛树脂改性处理对人工林轻木性能的影响

    谢序勤; 邱坚; 李君

    2014-01-01

    为了拓宽人工林轻木的应用领域,以酚醛树脂为处理液,分别采用常压、负压-负压浸渍法处理轻木.试样的性能检测结果显示:与对照材相比,处理试样的增重率、硬度及顺纹抗压强度均增加,尺寸稳定性改善.

  18. Synthesis, structural characterization, and performance evaluation of resorcinol-formaldehyde (R-F) ion-exchange resin

    The 177 underground storage tanks at the DOE's Hanford Site contain an estimated 180 million tons of high-level radioactive wastes. It is desirable to remove and concentrate the highly radioactive fraction of the tank wastes for vitrification. Resorcinol-formaldehyde (R-F) resin, an organic ion-exchange resin with high selectivity and capacity for the cesium ion, which is a candidate ion-exchange material for use in remediation of tank wastes. The report includes information on the structure/function analysis of R-F resin and the synthetic factors that affect performance of the resin. CS-100, a commercially available phenol-formaldehyde (P-F) resin, and currently the baseline ion-exchanger for removal of cesium ion at Hanford, is compared with the R-F resin. The primary structural unit of the R-F resin was determined to consist of a 1,2,3,4-tetrasubstituted resorcinol ring unit while CS-100, was composed mainly of a 1,2,4-trisubstituted ring. CS-100 shows the presence of phenoxy-ether groups, and this may account for the much lower decontamination factor of CS-100 for cesium ion. Curing temperatures for the R-F resin were found to be optimal at 105--130C. At lower temperatures, insufficient curing, hence crosslinking, of the polymer resin occurs and selectivity for cesium drops. Curing at elevated temperatures leads to chemical degradation. Optimal particle size for R-F resin is in the range of 20--50 mesh-sized particles. R-F resin undergoes chemical degradation or oxidation which destroys ion-exchange sites. The ion-exchange sites (hydroxyl groups) are converted to quinones and ketones. CS-100, though it has much lower performance for cesium ion-exchange, is significantly more chemically stable than R-F resin. To gamma radiation, CS-100 is more radiolytically stable than R-F resin

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

    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. PMID:27040248

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

    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.

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

    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.

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

    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.

  3. Preparation of mesoporous magnetic ion exchange resin and its removal performance-for the typical organic nitrogen derived from algae%介孔型磁性离子交换树脂的制备及其效能--针对典型藻源含氮有机物

    刘成; 何思源; 刘煜; 陈卫

    2016-01-01

    Mesoporous magnetic ion exchange resin (m-MIER) was synthesized using methyl acrylic glycidyl ester as monomer with the method of monomer polymerization. Its removal performance on the typical dissolved algal organic nitrogen was studied subsequent to some preliminary characterization. Magnetic ion exchange resin (MIEX®) was studied as a comparison simultaneously. The results showed that the lab synthetic m-MIER was mesoporous with the main pore diameter was from 2nm to 60nm, chloride was identified as the exchange group. Compared with MIEX®, m-MIER owned similar wet density, particle size, more abundant pore structure and greater exchange capacity (1.15g/cm3, 150~200µm, 0.1852cm3/g, 3.16mmol/g vs, 1.20g/cm3, 150~180µm, 0.0184cm3/g, 2.23mmol/g). The results of XPS indicated that the major component of the core was Fe3O4, and the m-MIER was quaternary ammonium anion exchange resin. The m-MIER exhibited better removal effects on the typical dissolved nitrogen derived algae cells compared with MIEX®and the removal rate was highly relevant with the categories of the dissolved organic nitrogen.%以甲基丙烯酸缩水甘油酯为单体,利用单体聚合法制备了介孔型磁性离子交换树脂(m-MIER),并在表征其基本性状的基础上,初步分析了其对典型藻源含氮有机物(藻蓝蛋白、氨基酸)的去除效能.为便于比较,研究过程中同步进行了磁性离子交换树脂(MIEX®)的研究.研究结果表明,m-MIER是以氯为交换基团的介孔型材料,其孔径为2~60nm;与MIEX®相比,m-MIER具有相似的湿视密度、粒径,更丰富的孔隙结构、更大的交换容量(1.15g/cm3,150~200μm,0.1852cm3/g,3.16mmol/g Vs 1.20g/cm3,150~180μm,0.0184cm3/g,2.23mmol/g);XPS图谱分析结果表明其内核成分主要为Fe3O4,且为季胺型阴离子交换树脂.针对藻源含氮有机物的去除结果表明,m-MIER对藻蓝蛋白、特定氨基酸的去除效果明显优于MIEX®,且去除效果与氨基酸的种类显著相关.

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

    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

  5. 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

    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

  6. Resin composites

    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 but...... 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<0.0001). More paramarginal enamel fractures were observed after loading in teeth restored with Grandio when compared to Charisma (p=0.......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 be...

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

    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.

  8. Surface-functionalized mesoporous carbon materials

    Dai, Sheng; Gorka, Joanna; Mayes, Richard T.

    2016-02-02

    A functionalized mesoporous carbon composition comprising a mesoporous carbon scaffold having mesopores in which polyvinyl polymer grafts are covalently attached, wherein said mesopores have a size of at least 2 nm and up to 50 nm. Also described is a method for producing the functionalized mesoporous composition, wherein a reaction medium comprising a precursor mesoporous carbon, vinyl monomer, initiator, and solvent is subjected to sonication of sufficient power to result in grafting and polymerization of the vinyl monomer into mesopores of the precursor mesoporous carbon. Also described are methods for using the functionalized mesoporous carbon, particularly in extracting metal ions from metal-containing solutions.

  9. A general thiol assay based on the suppression of fluorescence resonance energy transfer in magnetic-resin core-shell nanospheres coated with gold nanoparticles

    A simple, rapid and sensitive fluorescence resonance energy transfer (FRET) method is presented for the determination of thiols. It is based on the thiol-induced enhancement effect of the surfactant sodium dodecyl sulfate (SDS) on the efficiency of fluorescence resonance energy transfer (FRET) in nanospheres consisting of a magnetic (Fe3O4) core and a phenol-formaldehyde resin (PFR) shell containing gold nanoparticles (AuNPs). The luminescence of the core-shell nanospheres at excitation/emission wavelengths of 390/445 nm, respectively, is quenched by the AuNPs which act as energy acceptors. The interaction of AuNPs with thiol compounds in the presence of SDS suppresses FRET and gives rise to a fluorescent signal whose intensity is proportional to the thiol concentration. The analytical features of seven thiols (homocysteine, thioglycolic acid, glutathione, dodecanethiol, cysteamine, cysteine and N-acetylcysteine) were studied. Detection limits are in the range from 0.14 to 0.49 μmol L−1. The precision of the method, expressed as the relative standard deviation, ranges from 0.4 to 4.9 %. The method was applied to the determination of total thiols in water samples with recovery values between 88.7 and 104.6 %. (author)

  10. Templating mesoporous zeolites

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

    2008-01-01

    categorization of templating methods, the nature of the interface between the zeolite crystal and the mesopore exactly when the mesopore starts to form is emphasized. In solid templating, the zeolite crystal is in intimate contact with a solid material that is being removed to produce the mesoporosity. Similarly......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...

  11. Periodic Mesoporous Organosilica Nanorice

    Mohanty Paritosh

    2008-01-01

    Full Text Available Abstract A periodic mesoporous organosilica (PMO with nanorice morphology was successfully synthesized by a template assisted sol–gel method using a chain-type precursor. The PMO is composed of D and T sites in the ratio 1:2. The obtained mesoporous nanorice has a surface area of 753 m2 g−1, one-dimensional channels, and a narrow pore size distribution centered at 4.3 nm. The nanorice particles have a length of ca. 600 nm and width of ca. 200 nm.

  12. Crystalline mesoporous metal oxide

    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.

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

    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

  14. Immobilization of spent resin with epoxy resin

    immobilization of spent resin using epoxy resin has been conducted. The spent resin was mixtured with epoxy resin in variation of concentration, i.e., 30, 40, 50, 60, 70 weight percent of spent resin. The mixture were pour into the plastic tube, with a diameter of 40 mm and height of 40 mm. The density, compressive strength and leaching rate were respectively measured by quanta chrome, paul weber apparatus and gamma spectrometer. The results showed that the increasing of waste concentration would be decreased the compressive strength, and increased density by immobilized waste. The leaching rate of 137Cs from waste product was not detected in experiment (author)

  15. Studies on Lignin-Based Adhesives for Particleboard Panels

    ÇETİN, Nihat Sami; Özmen, Nilgül

    2003-01-01

    The ultimate aim of this work was to develop a phenolic resin for partially replacing phenol with modified organosolv lignin in phenol-formaldehyde (PF) resin production. The lignin-formaldehyde relationship was determined in a reactivity test. Organosolv lignin-phenol-formaldehyde (LPF) resins were produced in a two-step preparation with different additions of lignin. The method selected for the manufacture of lignin resins dealt with modification of the lignin by the methylolation route. Th...

  16. Resin Catalyst Hybrids

    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].

  17. A simple large-scale synthesis of mesoporous In2O3 for gas sensing applications

    Zhang, Su; Song, Peng; Yan, Huihui; Yang, Zhongxi; Wang, Qi

    2016-08-01

    In this paper, large-scale mesoporous In2O3 nanostructures were synthesized by a facile Lewis acid catalytic the furfural alcohol resin (FAR) template route for the high-yield. Their morphology and structure were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal and thermogravimetry analysis (DSC-TG) and the Brunauer-Emmett-Teller (BET) approach. The as-obtained mesoporous In2O3 nanostructures possess excellent mesoporous and network structure, which increases the contact area with the gases, it is conducive for adsorption-desorption of gas on the surface of In2O3. The In2O3 particles and pores were both about 15 nm and very uniform. In gas-sensing measurements with target gases, the gas sensor based on mesoporous In2O3 nanostructures showed a good response, short response-recovery time, good selectivity and stability to ethanol. These properties are due to the large specific surface area of mesoporous structure. This synthetic method could use as a new design concept for functional mesoporous nanomaterials and for mass production.

  18. Review: Resin Composite Filling

    Desmond Ng

    2010-02-01

    Full Text Available 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 composite has aesthetic advantages over amalgam, one of the major disadvantage include polymerization shrinkage and future research is needed on reaction kinetics and viscoelastic behaviour to minimize shrinkage stress.

  19. Resin Longevity Studies

    Radioactive resin waste has been generated at the Savannah River Site as a result of water treatment at F- and H-Areas. Key factors in the risk assessment of disposing of these materials in trenches include resin retention of 129I, a long-lived isotope, and the degradation rate of the organic resin itself. In order to estimate the degradation of resin wastes during underground burial, simulated aging studies were carried out with Dowex 21K, CG-8, and GT-73 ion exchange resins. These resins have a polystyrene-base but bear different functional groups. The specific resins considered in this study include anion (Dowex 21K), cation (CG8), and neutral (GT73) resins with, respectively, quaternary ammonium, sulfonate, and thiol functionalities. The objective of this study is to carry out laboratory experiments to simulate aging of organic resin wastes in order to (1) determine the functional life span of CG8, GT73 and Dowex 21K resins under field (trench) conditions, and (2) determine the expected performance of these resins as they degrade

  20. Breakthroughs in Mesoporous Composite Materials

    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-

  1. Hydrophilic and mesoporous SiO2-TiO2-SO3H system for fuel cell membrane applications

    Graphical abstract: The composite films containing SiO2-TiO2-SO3H resin additives, with strong water retention capabilities, showed superior proton conductivity, even at 120 oC and 25% RH, as well as a slightly improved current density at 30% RH and 70 oC, when compared to costly Nafion film. Display Omitted Research highlights: → The hydrophilic and mesoporous SiO2-TiO2-SO3H 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 SiO2-TiO2-SO3H composite films is superior to the commercial Nafion film. - Abstract: Hydrophilic and mesoporous sulfonated SiO2-TiO2-SO3H systems as new additives for fuel cell electrolyte membranes are directly synthesized by the binary sol-gel reaction of TEOS-TiCl4 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. Mesoporous molecular sieve catalysts

    Højholt, Karen Thrane

    the micropores. Furthermore, preliminary work was done using mesoporous ZSM-5 zeolites as support material for anchoring molecular CoMo6 species for the application as potential bi-functional catalyst in simultaneous hydrodesulfurisation (HDS) and hydrocracking. HDS activity tests revealed that the...... of different catalytic applications. Primarily the zeolites were modified regarding the porosity and the introduction of metals to the framework. The obtained materials were used as solid acid catalysts, as an inert matrix for stabilising metal nanoparticles and as an anchoring material for molecular...... only be used as solid acid catalysts but can also be used as a size-selective matrix. It was shown that it is possible to encapsulate 1-2 nm sized gold nanoparticles by silicalite-1 or ZSM-5 zeolite crystals thereby forming a sintering-stable and substrate size-selective oxidation catalyst. After...

  3. Synthesis and Characterization of Bimodal Mesoporous Silica

    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.

  4. [Utilization of organic resources in paper pulp waste liquid].

    Lin, Qiaojia; Liu, Jinghong; Yang, Guidi; Huang, Biao

    2005-04-01

    In this paper, one hundred percent of condensed sulfate paper pulp waste liquid was used as the raw material of adhesive, and the activation of its lignin as well as the improving effects of phenol formaldehyde resin and polyfunctional aqueous polymer isocyanate (PAPI) were studied. The results showed that adding formaldehyde to the waste liquid could increase the reactivity of contained lignin, and adding 30% phenol formaldehyde resin or 20% PAPI could make the waste liquid in place of pure phenol formaldehyde resin for producing class I plywood. Furthermore, the cost could be reduced by 55.5% and 49.0%, respectively, in comparing with pure phenol formaldehyde resin. This approach fully used the organic resources in paper pulp waste liquid, reduced environment pollution at the same time, and had unexceptionable economic, social and ecological benefits. The feasibility of preparing adhesives from paper pulp waste liquid was also analyzed by infrared spectrum. PMID:16011170

  5. Biocompatibility of composite resins

    Sayed Mostafa Mousavinasab

    2011-01-01

    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 concern...

  6. Resin performance monitor

    An ion exchange resin filled in a water cleaning device disposed in a nuclear power plant for maintaining water quality is transferred to a resin leaching vessel, to measure a TOC amount and molecular weight distribution of effluents from the resin. An amount of the effluents adsorbed to each of a pair ion exchange resins is evaluated based on the result, to forecast the extent of degradation of performance of the ion exchange resins due to the adsorption of the effluents. Then more realistic usage of the ion exchange resin is enabled by considering the effects of the effluents from the resin on the pair ion exchange resins, which has not been considered so far. Namely, since the desalting performance can be forecast at an initial stage of the cycle, requirement for the exchange of the resin and regeneration thereof can be judged appropriately, thereby enabling to maintain performance, for example, of a condensate desalting tower satisfactorily, which is also effective for cleaning water in a reactor primary system to high purity. (T.M.)

  7. Interactions of Plutonium and Lanthanides with Ordered Mesoporous Materials

    Parsons-Moss, Tashi

    Pu(IV), Pu(VI), Eu(III), Ce(III), and Zr(IV). The acetamide phosphonate functionalized silica called Ac-Phos-SBA-15 required more extensive synthesis than the other three functionalized silica materials. Development of functionalized mesoporous silica extractants for actinides is contingent on their synthesis and hydrolytic stability, and these two aspects of the Ac-Phos-SBA-15 material are discussed. This material showed the highest binding affinity for all of the target ions, and the sorption and desorption of Pu(VI) to Ac-Phos-SBA-15 was extensively investigated. Ordered mesoporous carbons are attractive as sorbents because of their extremely high surface areas and large pore volumes, and could be suitable substrates for the development of actinide sensors based on their electrochemical properties. Three different mesoporous carbon materials were synthesized by collaborators to test their application as radionuclide sorbent materials. The first is called CMK (carbons mesostructured by Korea Advanced Institute of Science and Technology), and was synthesized using a hard silica template with 3D-bicontinuous ordered mesostructure. Highly ordered body-centered cubic mesoporous carbon was synthesized by self-assembly of a phenol resin around a soft polymer template, and this material is known as FDU-16 (Fudan University). Etching of the silica portion of mesoporous carbon-silica composites created the 2D-hexagonal mesoporous carbon called C-CS (carbon from carbon-silica nanocomposites) with a bimodal pore size distribution. The as-synthesized nanocast mesoporous carbon in this work is called UN CMK, and the same material after oxidation treatment with nitric acid is called OX CMK. A portion of both FDU-16-type and C-CS-type ordered mesoporous carbons were oxidized with acidic ammonium persulfate, which created the oxidized carbon materials called FDU-16-COOH and C-CS-COOH, respectively. The mesoporous carbons were characterized by scanning electron microscopy to view

  8. WHEAT STRAW ALKALINE LIGNIN AND ITS DERIVATIVES AS RETENTION AID

    QuanxiaoLiu; BeihaiHe; HuaiyuZhan; ShuhuiYang; JianluLiu; ZhenxingPan; JianhuaLiu

    2004-01-01

    In this paper, a new type of retention system of PEO/cofactor retention system is introduced, the cofactors used are phenol-formaldehyde resin, wheat straw alkaline lignin and its derivatives such as hydroxymethylated lignin, sulfited lignin and lignin-based phenol-formaldehyde resin. The first pass retention of newsprint slurry and the properties of handsheet are improved by using the system. The results indicate that a new application field for lignin has been exploited.

  9. Aligned mesoporous architectures and devices.

    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.

  10. Mesoporous Silicate Materials in Sensing

    Paul T. Charles

    2008-08-01

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

  11. Single crystalline mesoporous silicon nanowires

    Hochbaum, Allon; Dargas, Daniel; Hwang, Yun Jeong; Yang, Peidong

    2009-08-18

    Herein we demonstrate a novel electroless etching synthesis of monolithic, single-crystalline, mesoporous silicon nanowire arrays with a high surface area and luminescent properties consistent with conventional porous silicon materials. The photoluminescence of these nanowires suggest they are composed of crystalline silicon with small enough dimensions such that these arrays may be useful as photocatalytic substrates or active components of nanoscale optoelectronic devices. A better understanding of this electroless route to mesoporous silicon could lead to facile and general syntheses of different narrow bandgap semiconductor nanostructures for various applications.

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

    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).

  13. Mesoporous C/CrN and C/VN Nanocomposites Obtained by One-Pot Soft-Templating Process

    Julien Kiener

    2016-07-01

    Full Text Available Nanocomposites of ordered mesoporous carbon associated with chromium nitride (CrN or vanadium nitride (VN nanoparticles were obtained by a simple one-pot synthesis based on the solvent evaporation induced self-assembly (EISA process using Pluronic triblock surfactant as soft-template and a phenol-based resin (resol as carbon precursor. These nanocomposites were characterized by X-ray diffraction, nitrogen physisorption and Transmission Electron Microscopy (TEM techniques. Electron tomography (or 3D-TEM technique was particularly useful for providing direct insight on the internal architecture of C/CrN nanocomposite. Nanocomposites showed a very well organized hexagonal mesoporous carbon structure and a relatively high concentration of nanoparticles well distributed in the porous network. The chromium and vanadium nitrides/mesoporous carbon nanocomposites could have many potential applications in catalysis, Li-ion batteries, and supercapacitors.

  14. Reduction of polyester resin shrinkage by means of epoxy resin

    The possibility was investigated of reducing the shrinkage of unsaturated polyester resin taking place in radiation-induced curing, by the addition of epoxy resin. In order to combine chemically both resins, the epoxy component was modified by introducing unsaturated bonds via acrylamide and N-hydroxymethyloloacrylamide. A composition of 90% unsaturated polyester resin and 10% acrylamide-modified epoxy resin, filled with silica (1:1.5), showed a volume shrinkage below 2%. (author)

  15. Magnetic mesoporous material for the sequestration of algae

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

    2014-09-09

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

  16. Phenol-formaldehyde oligomers application for coatings production применение фенолоформальдегидных олигомеров для производства покровныХ материалов

    Orlova Anzhela Manvelovna

    2011-11-01

    Full Text Available The description developed by the authors of structures and technologies production safety coatings based on glass fiber and paper, modified phenol-formaldehyde oligomers, which are possessed high physicochemical properties, durability and chemical durability, is presented.Приведено описание разработанных авторами составов и технологий получения защитно-покровных материалов на основе модифицированных фенолформальдегидными олигомерами стеклотканей и бумаги, обладающих высокими физико-химическими свойствами, долговечностью и химической стойкостью.

  17. Bimodal mesoporous silica with bottleneck pores.

    Reber, M J; Brühwiler, D

    2015-11-01

    Bimodal mesoporous silica consisting of two sets of well-defined mesopores is synthesized by a partial pseudomorphic transformation of an ordered mesoporous starting material (SBA-15 type). The introduction of a second set of smaller mesopores (MCM-41 type) establishes a pore system with bottlenecks that restricts the access to the core of the bimodal mesoporous silica particles. The particle size and shape of the starting material are retained, but micropores present in the starting material disappear during the transformation, leading to a true bimodal mesoporous product. A varying degree of transformation allows the adjustment of the pore volume contribution of the two mesopore domains. Information on the accessibility of the mesopores is obtained by the adsorption of fluorescence-labeled poly(amidoamine) dendrimers and imaging by confocal laser scanning microscopy. This information is correlated with nitrogen sorption data to provide insights regarding the spatial distribution of the two mesopore domains. The bimodal mesoporous materials are excellent model systems for the investigation of cavitation effects in nitrogen desorption isotherms. PMID:26399172

  18. Mesoporous Silicon-Based Anodes

    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).

  19. Synthesis of N-Doped Hollow-Structured Mesoporous Carbon Nanospheres for High-Performance Supercapacitors.

    Liu, Chao; Wang, Jing; Li, Jiansheng; Zeng, Mengli; Luo, Rui; Shen, Jinyou; Sun, Xiuyun; Han, Weiqing; Wang, Lianjun

    2016-03-23

    We have demonstrated a facile and controllable synthesis of monodispersed N-doped hollow mesoporous carbon nanospheres (N-HMCSs) and yolk-shell hollow mesoporous carbon nanospheres (N-YSHMCSs) by a modified "silica-assisted" route. The synthesis process can be carried out by using resorcinol-formaldehyde resin as a carbon precursor, melamine as a nitrogen source, hexadecyl trimethylammonium chloride as a template, and silicate oligomers as structure-supporter. The morphological (i.e., particle size, shell thickness, cavity size, and core diameter) and textural features of the carbon nanospheres are easily controlled by varying the amount of ammonium. The resultant carbon nanospheres possess high surface areas (up to 2464 m(2) g(-1)), large pore volumes (up to 2.36 cm(3) g(-1)), and uniform mesopore size (∼2.4 nm for N-HMCSs, ∼ 4.5 nm for N-YSHMCSs). Through combining the hollow mesoporous structure, high porosity, large surface area, and N heteroatomic functionality, the as-synthesized N-doped hollow-structured carbon nanospheres manifest excellent supercapacitor performance with high capacitance (up to 240 F/g), favorable capacitance retention (97.0% capacitive retention after 5000 cycles), and high energy density (up to 11.1 Wh kg(-1)). PMID:26942712

  20. Cleanup of demineralizer resins

    Radiocesium is being removed from demineralizers A and B (DA and DB) by a process that was developed from laboratory tests on small samples of resin from the demineralizers. The process was designed to elute the radiocesium from the demineralizer resins and then to resorb it onto the zeolite ion exchangers contained in the Submerged Demineralizer System (SDS). It was also required to limit the maximum cesium activities in the resin eluates (SDSD feeds) so that the radiation field surrounding the pipelines would not be excessive. The process consisted of 17 stages of batch elution. In the initial stage, the resin was contacted with 0.18 M boric acid. Subsequent stages subjected the resin to increasing concentrations of sodium in NaH2BO3-H3BO3 solution (total boron= 0.35 M) and then 1 M sodium hydroxide in the final stages. Results on the performance of the process in the cleanup of the demineralizers at TMI-2 are compared with those obtained from laboratory tests with small samples of the DA and DB resins. To date, 15 stages of batch elution have been completed on the demineralizers at TMI-2, which resulted in the removal of about 750 Ci of radiocesium from DA and about 3300 Ci from DB

  1. Surfactant-Templated Mesoporous Metal Oxide Nanowires

    Hongmei Luo; Qianglu Lin; Stacy Baber; Mahesh Naalla

    2010-01-01

    We demonstrate two approaches to prepare mesoporous metal oxide nanowires by surfactant assembly and nanoconfinement via sol-gel or electrochemical deposition. For example, mesoporous Ta2O5 and zeolite nanowires are prepared by block copolymer Pluronic 123-templated sol-gel method, and mesoporous ZnO nanowires are prepared by electrodeposition in presence of anionic surfactant sodium dodecyl sulfate (SDS) surfactant, in porous membranes. The morphologies of porous nanowires are studied by sca...

  2. Mesoporous metal oxide graphene nanocomposite materials

    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.

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

    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.

  4. Ordered mesoporous silica materials with complicated structures

    Han, Yu

    2012-05-01

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

  5. Cellular membrane trafficking of mesoporous silica nanoparticles

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

    2012-01-01

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

  6. Influência da composição da resina tanino-uréia-formaldeído nas propriedades físicas e macânicas de chapas aglomeradas Influence of the composition of tannin-urea-formaldehyde resins in the in the physical and mechanicals properties of particleboard

    Fabrício Gomes Gonçalves

    2008-08-01

    Full Text Available Na fabricação de aglomerados à base de madeira são utilizados adesivos sintéticos como melamina-formaldeído (MF, fenol-formaldeído (FF, uréia-formaldeído (UF, entre outros. Devido ao alto custo desses adesivos, pesquisas que visam a introdução de alterações nas suas formulações são importantes para a redução de custos no sistema produtivo. Desta forma, este trabalho teve como objetivo estudar a influência da adição de diferentes níveis de tanino de Acacia mearnsii em uma resina comercial à base de uréia-formaldeído nas propriedades físicas e mecânicas de chapas aglomeradas. As chapas aglomeradas foram confeccionadas com madeira de Eucalyptus urophylla. Foram avaliadas quatro composições de adesivo: T1 - 100% de resina UF (testemunha; (T2 90% de resina UF + 10% de tanino 50%; (T3 85% de resina UF + 15% de tanino 50% e (T4 70% de resina UF + 30% de tanino 50%. Através dos ensaios, conclui-se que é possível adicionar tanino à resina uréia-formaldeído sem com isso prejudicar as propriedades físicas e mecânicas das chapas.In the production of the wood base particleboards, synthetic adhesives are used as melamina-formaldehyde (MF, phenol-formaldehyde (FF, urea-formaldehyde (UF, among others. Due to the high cost of these adhesives, researches that a seek the introduction of alterations in their formulations are important for the reduction of costs in the productive system. This work had as objective verify the influence of the several levels of Acacia mearnsii tannin in a commercial resin of urea-formaldehyde an the physical and mechanical properties of the particleboard. The particleboard was produced with Eucalyptus urophylla wood. They were four treatments: T1 - 100% of resin UF (control; (T2 90% of the resin UF + 10% of the tannin 50%; (T3 85% of the resin UF + 15% of the tannin 50% and (T4 70% of the resin UF + 30% of the tannin 50%. The results showed that it is possible to add tannin to the resin urea

  7. Mesoporous Silicate Materials in Sensing

    Paul T. Charles; Johnson, Brandy J; Brian J. Melde

    2008-01-01

    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 e...

  8. Thermally conductive polymers

    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. General strategy for fabricating thoroughly mesoporous nanofibers

    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.

  10. Resin impregnation process for producing a resin-fiber composite

    Palmer, Raymond J. (Inventor); Moore, William E. (Inventor)

    1994-01-01

    Process for vacuum impregnation of a dry fiber reinforcement with a curable resin to produce a resin-fiber composite, by drawing a vacuum to permit flow of curable liquid resin into and through a fiber reinforcement to impregnate same and curing the resin-impregnated fiber reinforcement at a sufficient temperature and pressure to effect final curing. Both vacuum and positive pressure, e.g. autoclave pressure, are applied to the dry fiber reinforcement prior to application of heat and prior to any resin flow to compact the dry fiber reinforcement, and produce a resin-fiber composite of reduced weight, thickness and resin content, and improved mechanical properties. Preferably both a vacuum and positive pressure, e.g. autoclave pressure, are also applied during final curing.

  11. Nontoxic Resins Advance Aerospace Manufacturing

    2009-01-01

    The 2008 NASA Commercial Invention of the Year, PETI-330, is a polyimide matrix resin that performs well at high temperatures and is easily processed into composites in a simple, short curing cycle. Invented by scientists at Langley Research Center, PETI-330 is now licensed to Ube Industries, based in Japan with its American headquarters in New York. In addition to being durable and lightweight, the resin is also nontoxic, which makes it safe for workers to handle. PETI-330 was created specifically for heat-resistant composites formed with resin transfer molding and resin infusion, which formerly could only be used with low temperature resin systems.

  12. Single crystalline mesoporous silicon nanowires

    Hochbaum, A.I.; Gargas, Daniel; Jeong Hwang, Yun; Yang, Peidong

    2009-08-04

    Herein we demonstrate a novel electroless etching synthesis of monolithic, single-crystalline, mesoporous silicon nanowire arrays with a high surface area and luminescent properties consistent with conventional porous silicon materials. These porous nanowires also retain the crystallographic orientation of the wafer from which they are etched. Electron microscopy and diffraction confirm their single-crystallinity and reveal the silicon surrounding the pores is as thin as several nanometers. Confocal fluorescence microscopy showed that the photoluminescence (PL) of these arrays emanate from the nanowires themselves, and their PL spectrum suggests that these arrays may be useful as photocatalytic substrates or active components of nanoscale optoelectronic devices.

  13. Surfactant-Templated Mesoporous Metal Oxide Nanowires

    Hongmei Luo

    2010-01-01

    Full Text Available We demonstrate two approaches to prepare mesoporous metal oxide nanowires by surfactant assembly and nanoconfinement via sol-gel or electrochemical deposition. For example, mesoporous Ta2O5 and zeolite nanowires are prepared by block copolymer Pluronic 123-templated sol-gel method, and mesoporous ZnO nanowires are prepared by electrodeposition in presence of anionic surfactant sodium dodecyl sulfate (SDS surfactant, in porous membranes. The morphologies of porous nanowires are studied by scanning electron microscopy (SEM and transmission electron microscopy (TEM analyses.

  14. Drug Loading of Mesoporous Silicon

    Moffitt, Anne; Coffer, Jeff; Wang, Mengjia

    2011-03-01

    The nanostructuring of crystalline solids with low aqueous solubilities by their incorporation into mesoporous host materials is one route to improve the bioavailability of such solids. Earlier studies suggest that mesoporous Si (PSi), with pore widths in the range of 5-50 nm, is a candidate for such an approach. In this presentation, we describe efforts to load curcumin into free-standing microparticles of PSi. Curcumin is a compound extracted from turmeric root, which is an ingredient of curry. Curucmin has shown activity against selected cancer cell lines, bacteria, and other medical conditions. However, curcumin has a very low bioavailability due to its extremely low water solubility (0.6 μ g/mL). Incorporation of curcumin was achieved by straightforward loading of the molten solid at 185circ; C. Loading experiments were performed using PSi particles of two different size ranges, 45-75 μ m and 150-250 μ m. Longer loading times and ratio of curcumin to PSi leads to a higher percentage of loaded curcumin in both PSi particle sizes (as determined by weight difference). The extent of curcumin crystallinity was assessed by x-ray diffraction (XRD). The solubility and release kinetics of loaded curcumin from the PSi was determined by extraction into water at 37circ; C, with analysis using UV-VIS spectrometry. NSF-REU and TCU.

  15. Preparation of irregular mesoporous hydroxyapatite

    An irregular mesoporous hydroxyapatite (meso-HA), Ca10(PO4)6(OH)2, is successfully prepared from Ca(NO3)2.4H2O and NH4H2PO4 using surfactant cetyltrimethyl ammonium bromide (CTAB) as template. Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) results reveal that the positive head of CTAB is assembled on the surface precipitated HA and much NH4+ is enclosed in precipitated HA before calcination. Field scanning electron microscope (FSEM) reveals that there exist many interconnected pores throughout the HA reticular skeleton. Nitrogen adsorption-desorption experiment exhibits a mesoporous material type IV curve, and pore size distribution calculated from the desorption branch of the isotherms based on Barrett-Joyner-Halenda (BJH) model shows that most pores throughout the HA reticular skeleton are sized at about 40 nm, but the pores are not uniform on the whole, owning to decomposition of the 'organic' CTAB templating structures and ammonium salt enclosed in the precipitated HA. The specific surface area of irregular meso-HA is calculated to be 37.6 m2/g according to the Brunauer-Emmett-Teller (BET) equation. Moreover, after polylactic acid/meso-HA (PLA/meso-HA) composites degraded 12 weeks in normal saline at 37 deg. C, the interconnected pores throughout the HA skeleton were enlarged and sized in micron degree, which resemble trabecular bone structure very much

  16. High-temperature resins

    Serafini, T. T.

    1982-01-01

    The basic chemistry, cure processes, properties, and applications of high temperature resins known as polyimides are surveyed. Condensation aromatic polymides are prepared by reacting aromatic diamines with aromatic dianhydrides, aromatic tetracarboxylic acids, or with dialkyl esters of aromatic tetracarboxylic acids, depending on the intended end use. The first is for coatings or films while the latter two are more suitable for polyimide matrix resins. Prepreg solutions are made by dissolving reactants in an aprotic solvent, and advances in the addition of a diamine on the double bond and radical polymerization of the double bond are noted to have yielded a final cure product with void-free characteristics. Attention is given to properties of the Skybond, Pyralin, and NR-150B polyimide prepreg materials and characteristics of aging in the NP-150 polyimides. Finally, features of the NASA-developed PMR polyimides are reviewed.

  17. System for removing contaminants from plastic resin

    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.

  18. Synthesis and Properties of Phloroglucinol-Phenol-Formaldehyde Carbon Aerogels and Xerogels

    Jirglová, Hana; Pérez-Cadenas, A. F.; Maldonado-Hódar, F. J.

    2009-01-01

    Roč. 25, č. 4 (2009), s. 2461-2466. ISSN 0743-7463 Institutional research plan: CEZ:AV0Z40400503 Keywords : organic aerogels * immersion calorimetry * activated carbon Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.898, year: 2009

  19. 40 CFR 721.7220 - Polymer of substituted phenol, formaldehyde, epichlorohydrin, and disubstituted benzene.

    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...

  20. Mesoporous Silicon Far Infrared Filters Project

    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...

  1. Moderate Temperature Synthesis of Mesoporous Carbon

    Dua, Rubal

    2013-01-03

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

  2. Mesoporous hybrid organosilica containing urethane moieties

    Mesoporous hybrid material containing urethane moieties in functionalized long chain organic group have been synthesized by using bis[3-(triethoxysilyl) propyl urethane]ethane (BTESPUE) and tetraethoxysilane as structural ingredients. The incorporation of BTESPUE within the framework of mesoporous material was confirmed by Fourier transform-infrared, X-ray photoelectron spectroscopy, solid-state NMR spectroscopy and thermogravimetric analysis. This material had a thick wall and uniform pore, which may be attributed to the hydrogen bonding inside framework due to urethane moieties

  3. Nanostructured diluted magnetic semiconductors within mesoporous silica

    Brieler, Felix

    2005-01-01

    In this work the successful formation of several diluted magnetic semiconductors inside various mesoporous host matrices is shown. For that purpose, different high quality mesoporous silicas were synthesised. Because of the possibility to obtain nanostructured quantum wires inside the respective pore systems, hexagonally ordered structures of the MCM-41 and SBA-15 kind were chosen as hosts for the intra-pore formation of the DMS nanoparticles. Later on it became obvious though, that the forma...

  4. Direct liquid crystal templating of mesoporous silica

    Gordon-Smith, Tobias James

    2003-01-01

    The work described in this thesis is concerned with the development of ordered mesoporous silicas by direct templating from lyotropic liquid crystal phases of the surfactants Pluronic PI23, Pluronic F127, CTAB and Brij 78. The factors affecting the regularity, morphology, pore diameter and wall thickness of the templated mesoporous silicas were examined by exploring the reaction composition space and plotting the structural properties on TMOS/surfactant/water ternary diagrams. ...

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

    Yu, Yanjie

    2012-05-01

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

  6. [Acrylic resin removable partial dentures

    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

  7. Mesoporous Carbon for Capacitive Deionization of Saline Water

    Tsouris, Costas [ORNL; Mayes, Richard T [ORNL; Kiggans, Jim [ORNL; Sharma, Ms. Ketki [Georgia Institute of Technology; Yiacoumi, Sotira [Georgia Institute of Technology; DePaoli, David W [ORNL; Dai, Sheng [ORNL

    2011-01-01

    Self-assembled mesoporous carbon (MC) materials have been synthesized and tested for application in capacitive deionization (CDI) of saline water. MC was prepared by self-assembly of a triblock copolymer with hydrogen-bonded chains via a phenolic resin, such as resorcinol or phloroglucinol in acidic conditions, followed by carbonization and, in some cases, activation by KOH. Carbon synthesized in this way was ground into powder, from which activated MC sheets were produced. In a variation of this process, after the reaction of triblock copolymer with resorcinol or phloroglucinol, the gel that was formed was used to coat a graphite plate and then carbonized. The coated graphite plate in this case was not activated and was tested to serve as current collector during the CDI process. The performance of these MC materials was compared to that of carbon aerogel for salt concentrations ranging between 1000 ppm and 35,000 ppm. Resorcinol-based MC removed up to 15.2 mg salt per gram of carbon, while carbon aerogel removed 5.8 mg salt per gram of carbon. Phloroglucinol-based MC-coated graphite exhibited the highest ion removal capacity at 21 mg of salt per gram of carbon for 35,000 ppm salt concentration.

  8. Mesoporous carbon for capacitive deionization of saline water.

    Tsouris, C; Mayes, R; Kiggans, J; Sharma, K; Yiacoumi, S; DePaoli, D; Dai, S

    2011-12-01

    Self-assembled mesoporous carbon (MC) materials have been synthesized and tested for application in capacitive deionization (CDI) of saline water. MC was prepared by self-assembly of a triblock copolymer with hydrogen-bonded chains via a phenolic resin, such as resorcinol or phloroglucinol in acidic conditions, followed by carbonization and, in some cases, activation by KOH. Carbon synthesized in this way was ground into powder, from which activated MC sheets were produced. In a variation of this process, after the reaction of triblock copolymer with resorcinol or phloroglucinol, the gel that was formed was used to coat a graphite plate and then carbonized. The coated graphite plate in this case was not activated and was tested to serve as current collector during the CDI process. The performance of these MC materials was compared to that of carbon aerogel for salt concentrations ranging between 1000 ppm and 35,000 ppm. Resorcinol-based MC removed up to 15.2 mg salt per gram of carbon, while carbon aerogel removed 5.8 mg salt per gram of carbon. Phloroglucinol-based MC-coated graphite exhibited the highest ion removal capacity at 21 mg of salt per gram of carbon for 35,000 ppm salt concentration. PMID:22032802

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

    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.

  10. Indirect resin composites

    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.′

  11. Pore Narrowing of Mesoporous Silica Materials

    Christophe Detavernier

    2013-02-01

    Full Text Available To use mesoporous silicas as low-k materials, the pore entrances must be really small to avoid diffusion of metals that can increase the dielectric constant of the low-k dielectric. In this paper we present a new method to narrow the pores of mesoporous materials through grafting of a cyclic-bridged organosilane precursor. As mesoporous material, the well-studied MCM-41 powder was selected to allow an easy characterization of the grafting reactions. Firstly, the successful grafting of the cyclic-bridged organosilane precursor on MCM-41 is presented. Secondly, it is demonstrated that pore narrowing can be obtained without losing porosity by removing the porogen template after grafting. The remaining silanols in the pores can then be end-capped with hexamethyl disilazane (HMDS to make the material completely hydrophobic. Finally, we applied the pore narrowing method on organosilica films to prove that this method is also successful on existing low-k materials.

  12. Resin polymerization problems--are they caused by resin curing lights, resin formulations, or both?

    Christensen, R P; Palmer, T M; Ploeger, B J; Yost, M P

    1999-01-01

    Negative effects of rapid, high-intensity resin curing have been predicted for both argon lasers and plasma-arc curing lights. To address these questions, six different resin restorative materials were cured with 14 different resin curing lights representing differences in intensities ranging from 400 mW/cm2 to 1,900 mW/cm2; delivery modes using constant, ramped, and stepped methods; cure times ranging from 1 second to 40 seconds; and spot sizes of 6.7 mm to 10.9 mm. Two lasers, five plasma-arc lights, and seven halogen lights were used. Shrinkage, modulus, heat generation, strain, and physical changes on the teeth and resins during strain testing were documented. Results showed effects associated with lights were not statistically significant, but resin formulation was highly significant. Microfill resins had the least shrinkage and the lowest modulus. An autocure resin had shrinkage and modulus as high as or higher than the light-cured hybrid resins. Lasers and plasma-arc lights produced the highest heat increases on the surface (up to 21 degrees C) and within the resin restorations (up to 14 degrees C), and the halogen lights produced the most heat within the pulp chamber (up to 2 degrees C). Strain within the tooth was least with Heliomolar and greatest with Z100 Restorative and BISFIL II autocure resin. Clinical effects of strain relief were evident as white lines at the tooth-resin interface and cracks in enamel adjacent to the margins. This work implicates resin formulation, rather than light type or curing mode, as the important factor in polymerization problems. Lower light intensity and use of ramped and stepped curing modes did not provide significant lowering of shrinkage, modulus, or strain, and did not prevent enamel cracking adjacent to margins and formation of "white line" defects at the margins. Until materials with lower shrinkage and modulus are available, use of low-viscosity surface sealants as a final step in resin placement is suggested to

  13. Location of laccase in ordered mesoporous materials

    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.

  14. Location of laccase in ordered mesoporous materials

    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.

  15. A Single-Crystalline Mesoporous Quartz Superlattice.

    Matsuno, Takamichi; Kuroda, Yoshiyuki; Kitahara, Masaki; Shimojima, Atsushi; Wada, Hiroaki; Kuroda, Kazuyuki

    2016-05-10

    There has been significant interest in the crystallization of nanostructured silica into α-quartz because of its physicochemical properties. We demonstrate a single-crystalline mesoporous quartz superlattice, a silica polymorph with unprecedentedly ordered hierarchical structures on both the several tens of nanometers scale and the atomic one. The mesoporous quartz superlattice consists of periodically arranged α-quartz nanospheres whose crystalline axes are mostly oriented in an assembly. The superlattice is prepared by thermal crystallization of amorphous silica nanospheres constituting a colloidal crystal. We found that the deposition of a strong flux of Li(+) only on the surface of silica nanospheres is effective for crystallization. PMID:27060365

  16. Microstructure and application of mesoporous nanosize zirconia

    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.

  17. Orientation specific deposition of mesoporous particles

    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.

  18. EPOXY RESIN TOUGHENED BY THERMOPLASTICS

    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.

  19. Bending characteristics of resin concretes

    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.

  20. Bulk-Fill Resin Composites

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

    2015-01-01

    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...

  1. Liquid monobenzoxazine based resin system

    Tietze, Roger; Nguyen, Yen-Loan; Bryant, Mark

    2014-10-07

    The present invention provides a liquid resin system including a liquid monobenzoxazine monomer and a non-glycidyl epoxy compound, wherein the weight ratio of the monobenzoxazine monomer to the non-glycidyl epoxy compound is in a range of about 25:75 to about 60:40. The liquid resin system exhibits a low viscosity and exceptional stability over an extended period of time making its use in a variety of composite manufacturing methods highly advantageous.

  2. Synthetic Resin and Plastic Industries

    Banzon, Cesar P.

    1994-01-01

    To stimulate industrial efficiency and achieve competitiveness in domestic and external markets, the government has instituted Tariff Reform Program and the Import Liberalization Program. This study evaluates the performance and competitiveness of the resin and plastic industries in conjunction to the ongoing trade policy reform. It also describes the structure of the resin and plastic industries and identifies the factors affecting inter-firm and inter-industry differences in performance and...

  3. Periodic Mesoporous Organosilica Functionalized with Sulfonic Acid Groups as Acid Catalyst for Glycerol Acetylation

    Pascal Van Der Voort

    2013-08-01

    Full Text Available A Periodic Mesoporous Organosilica (PMO functionalized with sulfonic acid groups has been successfully synthesized via a sequence of post-synthetic modification steps of a trans-ethenylene bridged PMO material. The double bond is functionalized via a bromination and subsequent substitution obtaining a thiol functionality. This is followed by an oxidation towards a sulfonic acid group. After full characterization, the solid acid catalyst is used in the acetylation of glycerol. The catalytic reactivity and reusability of the sulfonic acid modified PMO material is investigated. The catalyst showed a catalytic activity and kinetics that are comparable with the commercially available resin, Amberlyst-15, and furthermore our catalyst can be recycled for several subsequent catalytic runs and retains its catalytic activity.

  4. Structure Evolution of Ordered Mesoporous Carbons Induced by Water Content of Mixed Solvents Water/Ethanol.

    Li, Peng; Liang, Shujun; Li, Zhenzhong; Zhai, Yan; Song, Yan

    2016-12-01

    In this work, mesostructure evolution of ordered mesoporous carbons (OMCs) from the 2-D hexagonal (space group p6mm) to the discontinuous cubic [Formula: see text], then towards the face-centered cubic lattice [Formula: see text], and finally, to the simple cubic Pm3n is achieved by simply adjusting the cosolvent water content of the mixed solvents water/ethanol in the presence of a reverse nonionic triblock copolymer and low molecular resin by evaporation-induced self-assembly method. Experimental results demonstrate that both the cosolvent and the reverse triblock copolymer play a key role in the mesophase transitions of OMCs. Furthermore, the OMCs with Pm3n symmetry are reported for the first time. Finally, the mechanism of mesostructure transition was discussed and proposed. PMID:27518232

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

    We have prepared multifunctional magnetic mesoporous Fe–CaSiO3 materials using triblock copolymer (P123) as a structure-directing agent. The effects of Fe substitution on the mesoporous structure, in vitro bioactivity, magnetic heating ability and drug delivery property of mesoporous CaSiO3 materials were investigated. Mesoporous Fe–CaSiO3 materials had similar mesoporous channels (5–6 nm) with different Fe substitution. When 5 and 10% Fe were substituted for Ca in mesoporous CaSiO3 materials, mesoporous Fe–CaSiO3 materials still showed good apatite-formation ability and had no cytotoxic effect on osteoblast-like MC3T3-E1 cells evaluated by the elution cell culture assay. On the other hand, mesoporous Fe–CaSiO3 materials could generate heat to raise the temperature of the surrounding environment in an alternating magnetic field due to their superparamagnetic property. When we use gentamicin (GS) as a model drug, mesoporous Fe–CaSiO3 materials release GS in a sustained manner. Therefore, magnetic mesoporous Fe–CaSiO3 materials would be a promising multifunctional platform with bone regeneration, local drug delivery and magnetic hyperthermia. (paper)

  6. Hollow mesoporous silica as a high drug loading carrier for regulation insoluble drug release.

    Geng, Hongjian; Zhao, Yating; Liu, Jia; Cui, Yu; Wang, Ying; Zhao, Qinfu; Wang, Siling

    2016-08-20

    The purpose of this study was to develop a high drug loading hollow mesoporous silica nanoparticles (HMS) and apply for regulation insoluble drug release. HMS was synthesized using hard template phenolic resin nanoparticles with the aid of cetyltrimethyl ammonium bromide (CTAB), which was simple and inexpensive. To compare the difference between normal mesoporous silica (NMS) and hollow mesoporous silica in drug loading efficiency, drug release behavior and solid state, NMS was also prepared by soft template method. Transmission electron microscopy (TEM), specific surface area analysis, FT-IR and zeta potential were employed to characterize the morphology structure and physicochemical property of these carriers. The insoluble drugs, carvedilol and fenofibrate(Car and Fen), were chosen as the model drug to be loaded into HMS and NMS. We also chose methylene blue (MB) as a basic dye to estimate the adsorption ability of these carriers from macroscopic and microscopic view, and the drug-loaded carriers were systematically studied by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and UV-vis spectrophotometry. What' more, the in vivo process of HMS was also study by confocal microscopy and in vivo fluorescence imaging. In order to confirm the gastrointestinal safety of HMS, the pathological examination of stomach and intestine also be evaluated. HMS allowed a higher drug loading than NMS and exhibited a relative sustained release curve, while NMS was immediate-release. And the effect of preventing drugs crystallization was weaker than NMS. As for in vivo process, HMS was cleared relatively rapidly from the mouse gastrointestinal and barely uptake by intestinal epithelial cell in this study due to its large particle size. And the damage of HMS to gastrointestinal could be ignored. This study provided a simple method to obtain high drug loading and regulation insoluble drug release, expanded the application of inorganic carriers in drug delivery system

  7. Mesoporous mordenite, preparation and use thereof

    Groen, J.C.; Moulijn, J.A.; Perez-Ramirez, J.

    2008-01-01

    The invention is directed to a process for the preparation of a mesoporous mordenite, which process comprises subjecting a non-dealuminated mordenite having an atomic ratio of framework Si-to-Al of least, to an alkaline treatment in order to create mesoporosity by removal of silicon, to various meso

  8. Mesoporous Transition Metal Oxides for Supercapacitors

    Yan Wang

    2015-10-01

    Full Text Available Recently, transition metal oxides, such as ruthenium oxide (RuO2, manganese dioxide (MnO2, nickel oxides (NiO and cobalt oxide (Co3O4, have been widely investigated as electrode materials for pseudo-capacitors. In particular, these metal oxides with mesoporous structures have become very hot nanomaterials in the field of supercapacitors owing to their large specific surface areas and suitable pore size distributions. The high specific capacities of these mesoporous metal oxides are resulted from the effective contacts between electrode materials and electrolytes as well as fast transportation of ions and electrons in the bulk of electrode and at the interface of electrode and electrolyte. During the past decade, many achievements on mesoporous transition metal oxides have been made. In this mini-review, we select several typical nanomaterials, such as RuO2, MnO2, NiO, Co3O4 and nickel cobaltite (NiCo2O4, and briefly summarize the recent research progress of these mesoporous transition metal oxides-based electrodes in the field of supercapacitors.

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

    Gao, Lin; Sun, Jihong; Li, Yuzhen

    2011-08-01

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

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

    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...... opposed to mesoporous single crystals. For the zeotype materials it was found that highly crystalline mesoporous materials of AFI and CHA structure types could be synthesized using a newly developed procedure. (c) 2006 Elsevier Inc. All rights reserved....

  11. ADSORPTION OF WATER AND BENZENE VAPOUR IN MESOPOROUS MATERIALS

    Paulina Taba

    2008-01-01

    Mesoporous materials have attracted the attention of many researchers due to the potential applications promised by the materials. This article discusses adsorption of water and benzene vapour in mesoporous materials (mesoporous silica: MCM-41, MCM-48 and their modification). MCM-41 and MCM-48 were synthesized hydrothermally at 100 oC using cethyltrimethylammonium chloride or dodecyltrimethylammonium bromide for MCM-41 (C16) or MCM-41 (C12) respectively and a mixture of cethyltrimethylammoniu...

  12. Functionalized Mesoporous Silica Membranes for CO2 Separation Applications

    Hyung-Ju Kim

    2015-01-01

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

  13. Catalyst-free synthesis of transparent, mesoporous diamond monoliths from periodic mesoporous carbon CMK-8

    Zhang, Li [Carnegie Inst. of Washington, Washington, DC (United States); Mohanty, Paritosh [Lehigh Univ., Bethlehem, PA (United States); Coombs, Neil [Univ. of Toronto, ON (Canada); Fei, Yingwei [Carnegie Inst. of Washington, Washington, DC (United States); Mao, Ho-kwang [Carnegie Inst. of Washington, Washington, DC (United States); Landskrom, Kai [Lehigh Univ., Bethlehem, PA (United States)

    2010-07-19

    We report on the synthesis of optically transparent, mesoporous, monolithic diamond from periodic mesoporous carbon CMK-8 at a pressure of 21 GPa. The phase transformation is already complete at a mild synthesis temperature of 1,300 °C without the need of a catalyst. Surprisingly, the diamond is obtained as a mesoporous material despite the extreme pressure. X-ray diffraction, SEM, transmission electron microscopy, selected area electron diffraction, high-resolution transmission electron microscopy, and Z-contrast experiments suggest that the mesoporous diamond is composed of interconnected diamond nanocrystals having diameters around 5–10 nm. The Brunauer Emmett Teller surface area was determined to be 33 m2 g-1 according Kr sorption data. The mesostructure is diminished yet still detectable when the diamond is produced from CMK-8 at 1,600 °C and 21 GPa. The temperature dependence of the porosity indicates that the mesoporous diamond exists metastable and withstands transformation into a dense form at a significant rate due to its high kinetic inertness at the mild synthesis temperature. The findings point toward ultrahard porous materials with potential as mechanically highly stable membranes.

  14. Uranium sorption by tannin resins

    The sorption of uranium by immobilised Eucalyptus Saligna Sm. and Lysiloma latisiliqua L tannins was investigated. Immobilization condition were analyzed. These resins resulted suitable adsorbent for the concentration of uranium from aqueous systems. The sorption of uranium is pH dependent. At pH 5.5 maximum in sorption capacity is registered. The presence of appreciable amount of sodium chloride do not have any effect on uranium removal. Carbonate and calcium ions in concentrations similar to these that could be found in sea water and other natural water do not decrease the uranium uptake. Tannin resins can be used several times without an appreciable decay of their sorption capacity

  15. Resin for processing radioactive waste water

    The present invention concerns an anionic exchange resin having a long service life with less radiation degradation. The resin is an anionic exchange resin in which a trimethyl ammonium group is introduced to a copolymer of 4-bromo-butoxymethyl styrene and divinyl benzene. The resin is excellent in economic performance, and can reduce the frequency for the exchange of cross-linked anionic exchangers. (T.M.)

  16. Thermal properties of ablative phenolic resins

    Srebrenkoska, Vineta; Dimeski, Dimko; BOGOEVA-GACEVA, Gordana

    2002-01-01

    Phenolic resins are known for their excellent thermal properties and chemical stability and are widely used in automotive industry, electrical engineering, military industry and industry of construction materials. Their attractive properties have been especially exploited in high temperature applications. Recently a wide range of phenolic resins for different applications is available on the market. In this paper the properties of two types of ablative phenolic resins are compared: resin B...

  17. Aerosol-generated mesoporous silicon oxycarbide particles

    Aerosol-generated mesoporous organosilica submicronic spheres have been converted into porous silicon oxycarbide (SiCO) glasses by pyrolysis at 1000 grad C in an inert atmosphere. Spherical mesoporous particles obtained from acidic solutions of 1,2-bis(triethoxysilyl) ethane and Pluronic F127 structuring agent were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption/desorption, and multi nuclear solid-state magic-angle spinning (MAS) NMR. These particles were then pyrolyzed at 1000 grad C and transformed into a SiCO phase as evidenced by 29Si MAS NMR, while TEM shows preserved mesoporosity, unfortunately difficult to access owing to the presence of an outer layer of dense silica. (authors)

  18. 21 CFR 177.1580 - Polycarbonate resins.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polycarbonate resins. 177.1580 Section 177.1580... Components of Single and Repeated Use Food Contact Surfaces § 177.1580 Polycarbonate resins. Polycarbonate... with the following prescribed conditions: (a) Polycarbonate resins are polyesters produced by: (1)...

  19. Method for removing contaminants from plastic resin

    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.

  20. Method of removing contaminants from plastic resins

    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.

  1. 21 CFR 177.1680 - Polyurethane resins.

    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...

  2. Porosity of micro/mesoporous composites

    Fojtíková, P.; Mintova, S.; Čejka, Jiří; Žilková, Naděžda; Zukal, Arnošt

    2006-01-01

    Roč. 92, 1-3 (2006), s. 154-160. ISSN 1387-1811 R&D Projects: GA ČR GA203/05/0197; GA MPO FT-TA/040 Institutional research plan: CEZ:AV0Z40400503 Keywords : micro/mesoporous composite * nitrogen adsorption * porous structure development Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.796, year: 2006

  3. Mesoporous Silica from Rice Husk Ash

    V.R. Shelke; S.S. Bhagade; S.A. Mandavgane

    2011-01-01

    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...

  4. Mesoporous Silica from Rice Husk Ash

    S.A. Mandavgane

    2010-12-01

    Full Text Available Mesoporous silica is used as a raw material in several areas: in preparation of catalysts, in inks, as aconcrete hardening accelerator, as a component of detergents and soaps, as a refractory constituent etc.Sodium silicate is produced by reacting rice hull ash (RHA with aqueous NaOH and silica is precipitatedfrom the sodium silicate by acidification. In the present work, conversion of about 90% of silica containedin RHA into sodium silicate was achieved in an open system at temperatures of about 100 °C. The resultsshowed that silica obtained from RHA is mesoporous, has a large surface area and small particle size.Rice Husk is usually mixed with coal and this mixture is used for firing boilers. The RHA therefore, usuallycontains carbon particles. Activated carbon embedded on silica has been prepared using the carbon alreadypresent in RHA. This carbon shows good adsorption capacity. ©2010 BCREC UNDIP. All rights reserved(Received: 25th April 2010, Revised: 17th June 2010, Accepted: 24th June 2010[How to Cite: V.R. Shelke, S.S. Bhagade, S.A. Mandavgane. (2010. Mesoporous Silica from Rice Husk Ash. Bulletin of Chemical Reaction Engineering and Catalysis, 5 (2: 63-67. doi:10.9767/bcrec.5.2.793.63-67

  5. Immobilization of Methyltrioxorhenium on Mesoporous Aluminosilicate Materials

    Martina Stekrova

    2014-03-01

    Full Text Available The presented report focuses on an in-depth detailed characterization of immobilized methyltrioxorhenium (MTO, giving catalysts with a wide spectra of utilization. The range of mesoporous materials with different SiO2/Al2O3 ratios, namely mesoporous alumina (MA, aluminosilicates type Siral (with Al content 60%–90% and MCM-41, were used as supports for immobilization of MTO. The tested support materials (aluminous/siliceous exhibited high surface area, well-defined regular structure and narrow pore size distribution of mesopores, and therefore represent excellent supports for the active components. Some of the supports were modified by zinc chloride in order to obtain catalysts with higher activities for instance in metathesis reactions. The immobilization of MTO was optimized using these supports and it was successful using all supports. The success of the immobilization of MTO and the properties of the prepared heterogeneous catalysts were characterized using X-ray Fluorescence (XRF, atomic absorption spectroscopy (AAS, X-ray powder diffraction (XRD, scanning electron microscopy (SEM, physical adsorption of N2, ultraviolet-visible spectroscopy (UV-Vis, infrared spectroscopy (FTIR, Fourier Transform Infrared Spectroscopy (FTIR using pyridine as a probe molecule and X-ray photoelectron spectroscopy (XPS. Furthermore, the catalytic activity of the immobilized MTO on the tested supports was demonstrated on metathesis reactions of various substrates.

  6. Continuous microwave flow synthesis of mesoporous hydroxyapatite

    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.

  7. Mesoporous Silica from Rice Husk Ash

    V.R. Shelke

    2011-01-01

    Full Text Available Mesoporous silica is used as a raw material in several areas: in preparation of catalysts, in inks, as a concrete hardening accelerator, as a component of detergents and soaps, as a refractory constituent etc. Sodium silicate is produced by reacting rice hull ash (RHA with aqueous NaOH and silica is precipitated from the sodium silicate by acidification. In the present work, conversion of about 90% of silica contained in RHA into sodium silicate was achieved in an open system at temperatures of about 100 °C. The results showed that silica obtained from RHA is mesoporous, has a large surface area and small particle size. Rice Husk is usually mixed with coal and this mixture is used for firing boilers. The RHA therefore, usually contains carbon particles. Activated carbon embedded on silica has been prepared using the carbon already present in RHA. This carbon shows good adsorption capacity. ©2010 BCREC UNDIP. All rights reserved(Received: 25th April 2010, Revised: 17th June 2010, Accepted: 24th June 2010[How to Cite: V.R. Shelke, S.S. Bhagade, S.A. Mandavgane. (2010. Mesoporous Silica from Rice Husk Ash. Bulletin of Chemical Reaction Engineering and Catalysis, 5 (2: 63-67. doi:10.9767/bcrec.5.2.793.63-67][DOI: http://dx.doi.org/10.9767/bcrec.5.2.793.63-67

  8. Continuous microwave flow synthesis of mesoporous hydroxyapatite

    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 Ca2+ 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

  9. Features material considerations polyester resins

    Алексеева, Н. Н.; Маслош, О. В.; Островерхова, И. А.; Маслош, В. З.

    2011-01-01

    The features of drafting of financial balance of processes of receipt of polyester resins are considered. It is marked that practical output of polyesters always anymore theoretical. The method of drafting of financial balance of processes of receipt of polyesters is offered.

  10. Contact allergy to epoxy resin

    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...

  11. Stochastic resin transfer molding process

    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.

  12. Generalized synthesis of mesoporous shells on zeolite crystals

    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.

  13. 40 CFR 414.40 - Applicability; description of the thermoplastic resins subcategory.

    2010-07-01

    ... the products classified under SIC 28213 thermoplastic resins including those resins and resin groups... *ABS-SAN Resins *Acrylate-Methacrylate Latexes *Acrylic Latex *Acrylic Resins *Cellulose Acetate Butyrates Cellulose Acetate Resin *Cellulose Acetates *Cellulose Acetates Propionates Cellulose...

  14. Spray drying of bead resins: feasibility tests

    Rockwell International has developed a volume reduction system for low-level reactor wastes based on drying the wastes in a heated-air spray dryer. The drying of slurries of sodium sulfate, boric acid, and powdered ion exchange resins was demonstrated in previous tests. The drying of bead ion exchange resins can be especially difficult due to the relatively large size of bead resins (about 500 to 800 microns) and their natural affinity for water. This water becomes part of the pore structure of the resins and normally comprises 50 t 60 wt % of the resin weight. A 76-cm-diameter spray dryer was used for feasibility tests of spray drying of cation and anion bead resins. These resins were fed to the dryer in the as-received form (similar to dewatered resins) and as slurries. A dry, free-flowing product was produced in all the tests. The volume of the spray-dried product was one-half to one-third the volume of the as-received material. An economic analysis was made of the potential cost savings that can be achieved using the Rockwel spray dryer system. In-plant costs, transportation costs, and burial costs of spray-dried resins were compared to similar costs for disposal of dewatered resins. A typical utility producing 170 m3 (6,000 ft3) per year of dewatered resins can save $600,000 to $700,000 per year using this volume reduction system

  15. Iron oxide nanoparticles stabilized inside highly ordered mesoporous silica

    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.

  16. [Study on absorbing volatile oil with mesoporous carbon].

    Yan, Hong-mei; Jia, Xiao-bin; Zhang, Zhen-hai; Sun, E; Yang Nan

    2014-11-01

    Clove oil and turmeric oil were absorbed by mesoporous carbon. The absorption ratio of mesoporous carbon to volatile oil was optimized with the eugenol yield and curcumol yield as criteria Curing powder was characterized by scanning electron microscopy (SEM) and differential scanning calorietry (DSC). The effects of mesoporous carbon on dissolution in vitro and thermal stability of active components were studied. They reached high adsorption rate when the absorption ratio of mesoporous carbon to volatile oil was 1:1. When volatile oil was absorbed, dissolution rate of active components had a little improvement and their thermal stability improved after volatile oil was absorbed by the loss rate decreasing more than 50%. Absorbing herbal volatile oil with mesoporous carbon deserves further studying. PMID:25850263

  17. Shape matters when engineering mesoporous silica-based nanomedicines.

    Hao, Nanjing; Li, Laifeng; Tang, Fangqiong

    2016-04-22

    Mesoporous silica nanomaterials have been successfully employed in the development of novel carriers for drug delivery. Numerous studies have been reported on engineering mesoporous silica-based carriers for drug loading, release, cellular uptake, and biocompatibility. A number of design parameters that govern the in vitro and in vivo performance of the carriers, including particle diameter, surface chemistry, and pore size, have been tuned to optimize nanomedicine efficacy. However, particle shape, which may generate a high impact on nanomedicine performance, has still not been thoroughly investigated. This is probably due to the limited availability of strategies and techniques to produce non-spherical mesoporous silica nanomaterials. Recent breakthroughs in controlling the particle shape of mesoporous silica nanomaterials have confirmed the important roles of shape on nanomedicine development. This review article introduces various fabrication methods for non-spherical mesoporous silica nanomaterials, including rod, ellipsoid, film, platelet/sheet, and cube, and the roles of particle shape in nanomedicine applications. PMID:26818852

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

    Jarian Vernimmen

    2011-11-01

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

  19. EDF specifications on nuclear grade resins

    Ion exchange resins are widely used across EDF, especially within the nuclear division for the purification of water. Important applications include primary circuit, secondary circuit and effluent treatment, which require high quality nuclear grade resins to retain the dissolved species, some of which may be radioactive. There is a need for more and more efficient purification in order to decrease worker dose during maintenance but also to decrease volumes of radioactive resin waste. Resin performance is subject to several forms of degradation, including physical, chemical, thermal and radioactive, therefore appropriate resin properties have to be selected to reduce such effects. Work has been done with research institutes, manufacturers and on EDF sites to select these properties, create specifications and to continuously improve on these specifications. An interesting example of research regarding resin performance is the resin degradation under irradiation. Resins used in the CVCS circuit of EDF nuclear power plants are subject to irradiation over their lifetime. A study was carried out on the effects of total integrated doses of 0.1, 1 and 10 MGy on typically used EDF mixed bed resins in a 'mini-CVCS' apparatus to simultaneously test actual primary circuit fluid. The tests confirmed that the resins still perform efficiently after a typical CVCS radiation dose. Certain resins also need additional specifications in order to maintain the integrity of the particular circuits they are used in. Recently, EDF has updated its requirements on these high purity nuclear grade resins, produced generic doctrines for all products and materials used on site which include resins of all grades, and as a result have also updated a guide on recommended resin usage for the French fleet of reactors. An overview of the evolutions will be presented. (authors)

  20. A highly ordered cubic mesoporous silica/graphene nanocomposite

    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

  1. Platinum nanopeapods: spatial control of mesopore arrangements by utilizing a physically confined space.

    Takai, Azusa; Sakamoto, Yasuhiro; Terasaki, Osamu; Yamauchi, Yusuke; Kuroda, Kazuyuki

    2013-08-26

    Spherical mesopores: Mesoporous Pt rods containing cage-type mesopores were prepared with porous anodic alumina membranes (PAAMs). It is noteworthy that spherical mesopores are aligned in the rods due to physical confinement by the PAAM channels. Both the mesopore alignment and the morphological control are realized simultaneously, which could be important for bottom-up approaches to nanometals with desirable structural features (see figure). PMID:23868357

  2. Recovery of platinum, tin and indium from spent catalysts in chloride medium using strong basic anion exchange resins

    Highlights: → Platinum, tin and indium recoveries from spent reforming catalysts. → Adsorption of metal chlorocomplexes on strongly basic anion-exchange resins. → Sequential desorption via elution with reducing (Pt, Sn) or complexing (In) agents. → The elements were recovered in very high yields. → The anion-exchange resins can be reused. - Abstract: This work describes a route for platinum recovery from spent commercial Pt and PtSnIn/Al2O3 catalysts using strong basic mesoporous and macroporous anion exchange resins (Cl- form). The catalysts were leached with aqua regia (75 oC, 20-25 min). Platinum adsorption was influenced by the presence of other metals which form chlorocomplexes (tin, indium) and also base metals (aluminum). However, it was possible to overcome this fact by a sequential desorption procedure. Aluminum was selectively removed from the resins by elution with 3 mol L-1 HCl. Platinum was desorbed passing 1 mol L-1 Na2S2O3 (pH 9). Tin was removed by elution with 0.1 mol L-1 ascorbic acid. Indium was removed using 0.1 mol L-1 EDTA as eluent. Desorption efficiency exceeded 99% for all metals. Metals were recovered in high yields (>98 wt%).

  3. Contribution of mesopores in MgO-templated mesoporous carbons to capacitance in non-aqueous electrolytes

    Kado, Yuya; Soneda, Yasushi; Yoshizawa, Noriko

    2015-02-01

    MgO-templated mesoporous carbons were fabricated by annealing trimagnesium dicitrate nonahydrate at various temperatures from 700 to 1000 °C with subsequent acid leaching of MgO. The obtained carbons contained a large amount of mesopores. Performances of electric double-layer capacitors using these carbons were examined for propylene carbonate electrolyte containing 1 M tetraethylammonium tetrafluoroborate. The mesoporous carbons synthesized at higher temperatures showed better rate capabilities. AC impedance measurements indicated that high-temperature annealing of the carbon precursors and the presence of mesopores were important for high rate performance. In addition, the contribution of mesopores to capacitance was more significant at higher current densities of 30 A g-1.

  4. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments

    Furuse, Adilson Yoshio; da Cunha, Leonardo Fernandes; Benetti, Ana Raquel;

    2007-01-01

    The purpose of this study was to investigate the effect of different surface treatments on shear bond strength of saliva-contaminated resin-resin interfaces. Flat resin surfaces were fabricated. In the control group, no contamination or surface treatment was performed. The resin surfaces of the...... of silane and adhesive system. Resin cylinders were placed over the treated surfaces. The specimens were stored in water or ethanol. Shear bond strength tests were performed and the mode of failure was evaluated. Data were submitted to two-way ANOVA and Dunnett T3 test. Contamination of resin...

  5. High Temperature Transfer Molding Resins

    Connell, John W. (Inventor); Smith, Joseph G., Jr. (Inventor); Hergenrother, Paul M. (Inventor)

    2000-01-01

    High temperature resins containing phenylethynyl groups that are processable by transfer molding have been prepared. These phenylethynyl containing oligomers were prepared from aromatic diamines containing phenylethynyl groups and various ratios of phthalic anhydride and 4-phenylethynlphthalic anhydride in glacial acetic acid to form a mixture of imide compounds in one step. This synthetic approach is advantageous since the products are a mixture of compounds and consequently exhibit a relatively low melting temperature. In addition, these materials exhibit low melt viscosities which are stable for several hours at 210-275 C, and since the thermal reaction of the phenylethynyl group does not occur to any appreciable extent at temperatures below 300 C, these materials have a broad processing window. Upon thermal cure at approximately 300-350 C, the phenylethynyl groups react to provide a crosslinked resin system. These new materials exhibit excellent properties and are potentially useful as adhesives, coatings, films, moldings and composite matrices.

  6. High-Temperature Polyimide Resin

    Vanucci, Raymond D.; Malarik, Diane C.

    1990-01-01

    Improved polyimide resin used at continuous temperatures up to 700 degrees F (371 degrees C). PMR-II-50, serves as matrix for fiber-reinforced composites. Material combines thermo-oxidative stability with autoclave processability. Used in such turbine engine components as air-bypass ducts, vanes, bearings, and nozzle flaps. Other potential applications include wing and fuselage skins on high-mach-number aircraft and automotive engine blocks and pistons.

  7. Boron sorption characteristics in resins

    The purpose of boron addition in a nuclear power plant is to control the reactivity. In PHWRs, it is injected into the moderator system in the form of boric anhydride solution, while in PHWRs, it is added to the primary heat transport system in the form of boric acid solution. The required boron levels in PHWRs are controlled by valving in strong base anion exchangers having exchangeable species in OD- form while in PHWRs, the same can be achieved by restoring to the use of Boron Thermal Regeneration System (BTRS). This system operates on the principle of existence of different amounts of various polyborate ions at different temperatures, solution pH's and the boric acid concentrations and on the reversible sorption of these polyions on strong base anion exchange resins. This report describes the salient features of boron sorption characteristics on four types of anion exchange resins, based on experimental data generated in the chemical laboratories of Reactor Engineering Division of the Bhabha Atomic Research Centre, Bombay. The report further makes an attempt to calculate the pH of the resin and solution phases and the percentages of different polyborates and undissociated boric acid, under the experimental conditions investigated. (author). 30 refs., 4 figs., 20 tables

  8. Development of tough, moisture resistant laminating resins

    Brand, R. A.; Harrison, E. S.

    1982-01-01

    Tough, moisture resistant laminating resins for employment with graphite fibers were developed. The new laminating resins exhibited cost, handleability and processing characteristics equivalent to 394K (250 F) curing epoxies. The laminating resins were based on bisphenol A dicyanate and monofunctional cyanates with hydrophobic substituents. These resins sorb only small quantities of moisture at equilibrium (0.5% or less) with minimal glass transition temperature depression and represent an improvement over epoxies which sorb around 2% moisture at equilibrium. Toughening was accomplished by the precipitation of small diameter particles of butadiene nitrile rubber throughout the resin matrix. The rubber domains act as microcrack termini and energy dissipation sites, allowing increased stress accommodation prior to catastrophic failure. A unique blend of amine terminated butadiene nitrile elastomer (MW 2,000) and a high nitrile content butadiene nitrile rubber yielded the desired resin morphology.

  9. Silica-based mesoporous nanoparticles for controlled drug delivery.

    Kwon, Sooyeon; Singh, Rajendra K; Perez, Roman A; Abou Neel, Ensanya A; Kim, Hae-Won; Chrzanowski, Wojciech

    2013-01-01

    Drug molecules with lack of specificity and solubility lead patients to take high doses of the drug to achieve sufficient therapeutic effects. This is a leading cause of adverse drug reactions, particularly for drugs with narrow therapeutic window or cytotoxic chemotherapeutics. To address these problems, there are various functional biocompatible drug carriers available in the market, which can deliver therapeutic agents to the target site in a controlled manner. Among the carriers developed thus far, mesoporous materials emerged as a promising candidate that can deliver a variety of drug molecules in a controllable and sustainable manner. In particular, mesoporous silica nanoparticles are widely used as a delivery reagent because silica possesses favourable chemical properties, thermal stability and biocompatibility. Currently, sol-gel-derived mesoporous silica nanoparticles in soft conditions are of main interest due to simplicity in production and modification and the capacity to maintain function of bioactive agents. The unique mesoporous structure of silica facilitates effective loading of drugs and their subsequent controlled release. The properties of mesopores, including pore size and porosity as well as the surface properties, can be altered depending on additives used to fabricate mesoporous silica nanoparticles. Active surface enables functionalisation to modify surface properties and link therapeutic molecules. The tuneable mesopore structure and modifiable surface of mesoporous silica nanoparticle allow incorporation of various classes of drug molecules and controlled delivery to the target sites. This review aims to present the state of knowledge of currently available drug delivery system and identify properties of an ideal drug carrier for specific application, focusing on mesoporous silica nanoparticles. PMID:24020012

  10. Relative Molecular Mass Distribution of BG Resins

    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.

  11. Epoxy Resins Modified with Vegetable Oils

    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...

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

    Kustova, Marina; Kustov, Arkadii; Christensen, Christina Hviid

    Zeolitcs are crystalline materials, which are widely used as solid acid catalysts and supports in many industrial processes. Recently, mesoporous MFI-type zeolite single crystals were synthesized by use of carbon particles as a mesopore template and sodium aluminate as the aluminum Source. With...... this technique, only zeolites with relatively low Al contents were reported (Si/Al ratio about 100). In this work, the preparation of aluminum-rich mesoporous MFI-type zeolite single crystals (Si/Al similar to 16-50) using aluminum isopropoxide as the aluminum Source is reported for the first time. All...

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

    Kustova, Marina; Kustov, Arkadii; Christensen, Christina Hviid

    2005-01-01

    Zeolitcs are crystalline materials, which are widely used as solid acid catalysts and supports in many industrial processes. Recently, mesoporous MFI-type zeolite single crystals were synthesized by use of carbon particles as a mesopore template and sodium aluminate as the aluminum Source. With...... this technique, only zeolites with relatively low Al contents were reported (Si/Al ratio about 100). In this work, the preparation of aluminum-rich mesoporous MFI-type zeolite single crystals (Si/Al similar to 16-50) using aluminum isopropoxide as the aluminum Source is reported for the first time. All...

  14. Mesoporous Trimetallic PtPdRu Spheres as Superior Electrocatalysts.

    Jiang, Bo; Ataee-Esfahani, Hamed; Li, Cuiling; Alshehri, Saad M; Ahamad, Tansir; Henzie, Joel; Yamauchi, Yusuke

    2016-05-17

    Mesoporous Trimetallic PtPdRu Spheres with well-defined spherical morphology and uniformly sized pores were synthesized in an aqueous solution using ascorbic acid as the reducing agent and triblock copolymer F127 as the pore directing agent. These mesoporous PtPdRu spheres exhibited enhanced electrocatalytic activity compared to commercial Pt black, resulting in a ∼4.9 times improvement in mass activity for the methanol oxidation reaction. The excellent electrocatalytic activity and stability are due to the unique mesoporous architecture and electronic landscape between different elements. PMID:27072776

  15. 21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Xylene-formaldehyde resins condensed with 4,4â²... Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins. The...) The resins are produced by the condensation of xylene-formaldehyde resin and...

  16. Novel silica-based ion exchange resin

    NONE

    1997-11-01

    Eichrom`s highly successful Diphonixo resin resembles a conventional ion exchange resin in its use of sulfonic acid ligands on a styrene- divinylbenzene matrix. Diphonix resin exhibits rapid exchange kinetics that allow economical operation of ion exchange systems. Unlike conventional resins, Diphonix resin contains chelating ligands that are diphosphonic acid groups that recognize and remove the targeted metals and reject the more common elements such as sodium, calcium and magnesium. This latter property makes Diphonix ideal for many industrial scale applications, including those involving waste treatment. For treatment of low-level, transuranic (TRU) and high- level radioactive wastes, Diphonix`s polystyrene backbone hinders its application due to radiolytic stability of the carbon-hydrogen bonds and lack of compatibility with expected vitrification schemes. Polystyrene-based Diphonix is approximately 60% carbon- hydrogen. In response to an identified need within the Department of Energy for a resin with the positive attributes of Diphonix that also exhibits greater radiolytic stability and final waste form compatibility, Eichrom has successfully developed a new, silica-based resin version of Diphonix. Target application for this new resin is for use in environmental restoration and waste management situations involving the processing of low-level, transuranic and high-level radioactive wastes. The resin can also be used for processing liquid mixed waste (waste that contains low level radioactivity and hazardous constituents) including mixed wastes contaminated with organic compounds. Silica-based Diphonix is only 10% carbon-hydrogen, with the bulk of the matrix silica.

  17. Bending rigidity of composite resin coating clasps.

    Ikebe, K; Kibi, M; Ono, T; Nokubi, T

    1993-12-01

    The purpose of this study is to examine the bending profiles of composite resin coating cast clasps. The cobalt-chromium alloy cast clasps were made using tapered wax pattern. Silane coupling method (Silicoater MD, Kulzer Co.) was used to attach composite resin to metal surface. The breakage and the bending rigidity of composite resin coating clasps were evaluated. Results were as follows: 1) After the repeated bending test to the tips of clasp arm at 10,000 times in 0.25 mm deflection, neither crack on composite resin surface nor separation at resin/metal interface was observed in any specimen. 2) There was no significant difference in the bending rigidity of clasp arms between before and after composite resin coating. From these results, it was demonstrated that the composite resin coating cast clasp was available in clinical cases and coating with composite resin had little influence on the bending rigidity of clasp arms. Therefore, it was suggested that our clasp designing and fabricating system to control the bending rigidity of clasp arms could be applied to composite resin coating clasps. PMID:8935086

  18. Radiation degradation in organic ion exchange resins

    The EPICOR-2 Resin/Liner Investigation: Low-Level Waste Data Base Development Program, funded by the US Nuclear Regulatory Commission, studied the degradation effects in EPICOR-II organic ion exchange resins caused by internal radiation. Results of the third sampling analysis of ion exchange resins from prefilters PF-8 and PF-20 are compared with baseline data from tests performed on unirradiated resins and with results from the first and second samplings to determine if degradation has occurred because of the high internal radiation dose. Those results are also compared to findings of other researchers

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

    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

  20. Smart Mesoporous Nanomaterials for Antitumor Therapy

    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.

  1. Gated Silica Mesoporous Materials in Sensing Applications.

    Sancenón, Félix; Pascual, Lluís; Oroval, Mar; Aznar, Elena; Martínez-Máñez, Ramón

    2015-08-01

    Silica mesoporous supports (SMSs) have a large specific surface area and volume and are particularly exciting vehicles for delivery applications. Such container-like structures can be loaded with numerous different chemical substances, such as drugs and reporters. Gated systems also contain addressable functions at openings of voids, and cargo delivery can be controlled on-command using chemical, biochemical or physical stimuli. Many of these gated SMSs have been applied for drug delivery. However, fewer examples of their use in sensing protocols have been reported. The approach of applying SMSs in sensing uses another concept-that of loading pores with a reporter and designing a capping mechanism that is selectively opened in the presence of a target analyte, which results in the delivery of the reporter. According to this concept, we provide herein a complete compilation of published examples of probes based on the use of capped SMSs for sensing. Examples for the detection of anions, cations, small molecules and biomolecules are provided. The diverse range of gated silica mesoporous materials presented here highlights their usefulness in recognition protocols. PMID:26491626

  2. CHARACTERIZATION OF GLUED LAMINATED PANELS PRODUCED WITH STRIPS OF BAMBOO (Guadua magna) NATIVE FROM THE BRAZILIAN CERRADO

    Teixeira, Divino Eterno; Bastos, Rodrigo Pinheiro; Almeida, Sergio Alberto de Oliveira

    2015-01-01

    Panels were produced with strips of bamboo (Guadua magna) in layers crossed at angles of 90° and bonded with phenol-formaldehyde or PVA based resin, glued in three and five plies. The panels were tested and the physical and mechanical properties determined. The tests were primarily related to the...

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

    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.

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

    Liu, Fang, E-mail: liufangfw@163.com; Gao, Ya; Zhang, Shuang; Yan, Xi; Fan, Fengtao; Zhao, Chaocheng; Sun, Juan [China University of Petroleum(East China), Department of Chemical Engineering (China)

    2016-02-15

    Mesoporous carbon (MC) was prepared in soft template, and potassium ferricyanide was added into MC to prepare the modified mesoporous carbon (MMC). TEM, SEM, FT-IR, and N{sub 2} adsorption–desorption were used to characterize the textural properties of mesoporous materials. The BET specific surface area, pore volume, and the pore size of MC and MMC were 607.6321 and 304.7475 m{sup 2}/g, 0.313552 and 0.603573 cm{sup 3}/g, and 5.4356 and 7.9227 nm, respectively. The adsorption capabilities of MC and MMC were compared with the silica mesoporous material MCM-41. The influences of different adsorption conditions were optimized. For MC, the optimums of adsorbent dose, DMF initial concentration, rotating speed, and pH were 0.002 mg/50 mL, 200 mg/L, 200 r/min, and 4, respectively. MMC showed the highest DMF adsorption capacity at adsorbent dose 0.002 g/50 mL, DMF initial concentration 1000 mg/L, rotating speed 1000 r/min, pH more than 9, and contact time of less than 20 min. Meanwhile for MC, MMC, Pseudo-second-order equation was used to fit adsorption kinetics data. And adsorption process could be well fitted by Langmuir and Freundlich adsorption isotherms of MC, MMC. The results showed that MMC was a perfect adsorbent for DMF, and it was easy to separation and recycle. The recycling property of MMC was still relatively better than other two adsorbents.

  5. Micro/mesoporous composites based on colloidal zeolite grown in mesoporous matrix

    Prokešová, Pavla; Petkov, N.; Čejka, Jiří; Mintova, S.; Bein, T.

    2005-01-01

    Roč. 70, - (2005), s. 1829-1847. ISSN 0010-0765 R&D Projects: GA ČR GA203/05/0197; GA AV ČR KJB4040402 Institutional research plan: CEZ:AV0Z40400503 Keywords : micro/mesoporous composite * colloidal zeolites * colloids * molecular sieves Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.949, year: 2005

  6. Polyimide Resins Resist Extreme Temperatures

    2009-01-01

    Spacecraft and aerospace engines share a common threat: high temperature. The temperatures experienced during atmospheric reentry can reach over 2,000 F, and the temperatures in rocket engines can reach well over 5,000 F. To combat the high temperatures in aerospace applications, Dr. Ruth Pater of Langley Research Center developed RP-46, a polyimide resin capable of withstanding the most brutal temperatures. The composite material can push the service temperature to the limits of organic materials. Designed as an environmentally friendly alternative to other high-temperature resins, the RP-46 polyimide resin system was awarded a 1992 "R&D 100" award, named a "2001 NASA Technology of the Year," and later, due to its success as a spinoff technology, "2004 NASA Commercial Invention of the Year." The technology s commercial success also led to its winning the Langley s "Paul F. Holloway Technology Transfer Award" as well as "Richard T. Whitcom Aerospace Technology Transfer Award" both for 2004. RP-46 is relatively inexpensive and it can be readily processed for use as an adhesive, composite, resin molding, coating, foam, or film. Its composite materials can be used in temperatures ranging from minus 150 F to 2,300 F. No other organic materials are known to be capable of such wide range and extreme high-temperature applications. In addition to answering the call for environmentally conscious high-temperature materials, RP-46 provides a slew of additional advantages: It is extremely lightweight (less than half the weight of aluminum), chemical and moisture resistant, strong, and flexible. Pater also developed a similar technology, RP-50, using many of the same methods she used with RP-46, and very similar in composition to RP-46 in terms of its thermal capacity and chemical construction, but it has different applications, as this material is a coating as opposed to a buildable composite. A NASA license for use of this material outside of the Space Agency as well as

  7. Curing kinetics of alkyd/melamine resin mixtures

    Jovičić Mirjana C.; Radičević Radmila Ž.

    2009-01-01

    Alkyd resins are the most popular and useful synthetic resins applied as the binder in protective coatings. Frequently they are not used alone but are modified with other synthetic resins in the manufacture of the coatings. An alkyd/melamine resin mixture is the usual composition for the preparation of coating called 'baking enamel' and it is cured through functional groups of resins at high temperatures. In this paper, curing kinetics of alkyd resins based on castor oil and dehydrated castor...

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

    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.

  9. Novel method to incorporate Si into monodispersed mesoporous carbon spheres.

    Yano, Kazuhisa; Tatsuda, Narihito; Masuda, Takashi; Shimoda, Tatsuya

    2016-10-01

    Liquid silicon precursor is used as a silicon source and very simple and easy method for the incorporation of Si into mesoporous carbon spheres is presented. By using capillary condensation, the liquid precursor, Cyclopentasilane, penetrates into mesopores of carbon spheres homogeneously and subsequent heating brings the decomposition of the precursor and the formation of silicon inside meso-channels of carbon even though the decomposition is done much higher than the boiling point of the precursor. The homogeneous distribution of silicon is verified by EDX mapping of the composite as well as SEM observation of the calcined one. More than 45wt% of Si can be incorporated into mesopores by just one operation. The Si@mesoporous carbon composite works as an anode for a Lithium ion battery. PMID:27344486

  10. Thermally stable crystalline mesoporous metal oxides with substantially uniform pores

    Wiesner, Ulrich; Orilall, Mahendra Christopher; Lee, Jinwoo; DiSalvo, Jr., Francis J

    2015-01-27

    Highly crystalline metal oxide-carbon composites, as precursors to thermally stable mesoporous metal oxides, are coated with a layer of amorphous carbon. Using a `one-pot` method, highly crystalline metal oxide-carbon composites are converted to thermally stable mesoporous metal oxides, having highly crystalline mesopore walls, without causing the concomitant collapse of the mesostructure. The `one-pot` method uses block copolymers with an sp or sp 2 hybridized carbon containing hydrophobic block as structure directing agents which converts to a sturdy, amorphous carbon material under appropriate heating conditions, providing an in-situ rigid support which maintains the pores of the oxides intact while crystallizing at temperatures as high as 1000 deg C. A highly crystalline metal oxide-carbon composite can be heated to produce a thermally stable mesoporous metal oxide consisting of a single polymorph.

  11. Structure and optical properties of mesoporous tungsten oxide

    Mesoporous WO3 was prepared by the sol-gel process and the structure and the optical properties have been investigated. Various techniques were used for characterization of mesoporous WO3, including Fourier transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption-desorption isotherms and UV-vis spectroscopy. TEM and XRD analyses demonstrated that the mesoporous WO3 was nanocrystalline. The estimated optical band gap (E g) for the mesoporous WO3 was 3.5 eV. We present evidence for a photoreduction of W6+ into W5+ following the irradiation with UV-light. The change in coloration is almost reversible as exposed in oxidation environment. These results suggest that the potential applications of mesostructured WO3 with nanocrystals in the design of optical devices

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

    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...

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

    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.

  14. Preparation of Helical Mesoporous Ethenylene-silica Nanofibers with Lamellar Mesopores on Their Surface

    Zhang Ming; Li Yi; Bi Lifeng; Zhuang Wei; Wang Sibing; Chen Yuanli; Li Baozong; Yang Yonggang

    2011-01-01

    The morphologies and pore architectures of mesoporous ethenylene-silica were controlled using cetyl-trimethylammonium bromide (CTAB) as template and (S)-β-citroneliol as a co-structure-directing agent under basic conditions. When the (S)-β-citronellol/CTAB molar ratios are in the range of 0.75-2.0, helical nanofibers were ob-tained. With increasing the (S)-β-citronellol/CTAB molar ratio, the lengths of the nanofibers increases. Lamellar mesopores were identified on the surfaces of the nanofibers prepared in the (S)-β-citronellol/CTAB molar ratio range of 1.5-2.0. At the (S)-β-citronellol/CTAB molar ratio of 2.5 : 1, nanoparticles with nanoflakes on the sur-faces were obtained. The field emission scanning electron microscopy images taken after different reaction times indicated that the helical pitches of the nanofibers decreased with increasing the reaction time. Helical 1,4-phenylene-silica and methylene-silica nanofibers were also prepared. The results indicated that the morpholo-gies and pore architectures of the obtained organic-inorganic hybrid silicas are also sensitive to the hybrid silica precursors. Helical ethenylene-silica nanofibers with lamellar mesopores on their surfaces can be also prepared us-ing the mixtures of CTAB and racemic citronellol within a narrower citronellol/CTAB molar ratio range.

  15. Structural Determination of Copolymers from the Cross-catalyzed Reactions of Phenol-formaldehyde and Polymeric Methylenediphenyl Diisocyanate

    Haupt, Robert A

    2013-01-01

    This work reports the elucidation of the structure of a copolymer generated by the cross- catalyzed reactions of PF and pMDI prepolymers.  The electronic behavior of phenolic monomers as perturbed by alkali metal hydroxides in an aqueous environment was studied with 1H and 13C NMR.  Changes in electronic structure and thus reactivity were related to solvated ionic radius, solvent dielectric constant, and their effect on ion generated electric field strength. NMR chemical shifts were used to p...

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

    Abrar Muslim

    2010-12-01

    Full Text Available 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 concentrations of thiosulfate in the NARS system. Keywords: equilibrium, gold loading, resin capacity, thiosulfate, trithionate

  17. Synthesis, Characterization and Pore Structure Analysis of Mesoporous Materials

    Saldarriaga Lopez, Laura Carolina

    2014-01-01

    Self-assembly provides a route to make mesoporous structures that have accessible internal surface area. These types of materials show promise for use in opto-electronic devices as well as for energy storage devices. In this work we synthesize a range of mesoporous thin films from molecular and nanocrystal precursors. We characterize these films' porous structure and surface area using ellipsometric-porosimetry. This work is divided into three parts; the first section focuses on synthesizing ...

  18. Solar hydrogen and solar electricity using mesoporous materials

    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

  19. Interactions of Plutonium and Lanthanides with Ordered Mesoporous Materials

    Parsons-Moss, Tashi

    2014-01-01

    Ordered mesoporous materials are porous solids with a regular, patterned structure composed of pores between 2 and 50 nm wide. Such materials have attracted much attention in the past twenty years because the chemistry of their synthesis allows control of their unique physicochemical properties, which can be tuned for a variety of applications. Generally, ordered mesoporous materials have very high specific surface areas and pore volumes, and offer unique structures that are neither crystalli...

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

    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

  1. FABRICATION AND STUDY OF LIGNOCELLULOSIC HIBISCUS SABDARIFFA FIBER REINFORCED POLYMER COMPOSITES

    Amar Singh Singha; Vijay Kumar Thakur

    2008-01-01

    Fabrication of polymer composites reinforced with lignocellulosic materials has increased considerably during the last few years. This work reports the synthesis of natural fiber reinforced phenol-formaldehyde (PF) resin matrix based polymer composite using a compression molding technique. Initially the PF resin was prepared by varying the concentration of formaldehyde with a fixed weight of phenol. Polymeric resin of different P: F ratios were subjected for optimization of their mechanical p...

  2. Epoxidation of linseed oil-Alkyd resins

    Three types of different linseed oil-alkyd resin ( Alk (I), Alk (II), and Alk (III) ) were prepared with the calculated amounts of mono glycerides and adipic acid (1:1, 1:2, and 2:1 Eq.Wt) respectively via monoglyceride method. The obtained alkyd resins were epoxidized via reaction with the calculated quantities of peracetic acid, which was prepared by the reaction of acetic anhydride with H2O2. Epoxidation occurred with the ratio (1: 1, 1 :3, and 1:6 Eq. Wt) of alkyd to peracetic acid. The effect of reaction time on the epoxy group content was measured during the epoxidation process. The prepared alkyd resins were analyzed by IR and H1NMR. The metal coated film properties of epoxidized alkyd resins were compared with those of unmodified alkyd resins. It was observed that the coating films of epoxidized alkyd resins have better in drying properties, hardness, adhesion, impact and flexibility than those of un epoxidized alkyd resins. The flammability properties of the paper coated films for the prepared brominated epoxidized alkyd resins were found to be fire retardant

  3. Some experiences with epoxy resin grouting compounds.

    Hosein, H R

    1980-07-01

    Epoxy resin systems are used in tiling and grouting in the construction industry. Because of the nature of the application, skin contact is the primary hazard. The most prevalent reaction was reddening of the forearms, followed by whole body reddening and loss of appetite, these latter two being associated with smoking while applying the resin. PMID:7415974

  4. Terpenoid Oligomers of Dammar Resin.

    Bonaduce, Ilaria; Di Girolamo, Francesca; Corsi, Iacopo; Degano, Ilaria; Tinè, Maria Rosaria; Colombini, Maria Perla

    2016-04-22

    Dammar is a triterpenoid resin containing a volatile fraction, a monomeric fraction, and a high-molecular weight fraction. Although the low-molecular-weight components comprising sesquiterpenoids and triterpenoids have been extensively studied, the nature of the macromolecular components is still not fully understood, and different and sometimes contradictory theories have been proposed. The aim of this paper is to clarify the nature of the macromolecular components of dammar resin. A multianalytical approach was adopted based on thermoanalytical-thermogravimetric analysis (TGA), and thermogravimetric analysis coupled with Fourier transform infrared spectroscopy (TGA/FTIR)-and mass spectrometric techniques-direct exposure mass spectrometry (DE/MS), pyrolysis coupled to gas chromatography and mass spectrometry (Py/GC/MS), flow injection analysis electrospray ionization mass spectrometry (FIA/ESI/MS), and gas chromatography/mass spectrometry (GC/MS). The data indicate that the oligomeric fraction comprises triterpenoids bound through ester bonds, and that these triterpenoids are the same as those found in the free terpenoid fraction. The oligomeric fraction also includes triterpenoids containing carbonyl moieties, such as formyl groups, thus suggesting that these are involved in the esters in their corresponding enolic form. PMID:26981624

  5. Evaluation of resins for provisional restorations.

    Burgess, J O; Haveman, C W; Butzin, C

    1992-06-01

    An in vivo study of two resin materials (Barricaid and Caulk Temporary Crown and Bridge Resin) was done to determine the retention, post-operative sensitivity, and fabrication time of provisional restorations made from these materials. Following the placement of these resins in 67 intracoronal cavity preparations of 19 adult patients, a baseline evaluation was made which included a clinical examination and color slides. Twenty-four hours after the temporary restorations were placed, the patients completed evaluations of the post-operative sensitivity experienced. There was no difference in post-operative sensitivity between the teeth restored with Barricaid or Caulk Temporary Crown and Bridge Resin. At the insertion appointment of the final restoration, the interim restoration's success rate was determined. There was no difference between the retention of the two provisional materials. Fabrication time was significantly different with Barricaid restorations requiring less than one-half the fabrication time of the Caulk Temporary Crown and Bridge Resin material. PMID:1388950

  6. Electrodialytic decontamination of spent ion exchange resins

    Development of a novel electrodialytic decontamination process for the selective removal of radioactive Cs from spent ion exchange resins containing large amounts of Li is described. The process involves passage of a dc electric current through a bed of the spent ion exchange resin in a specially designed electrodialytic cell. The radiocesium so removed from a volume of the spent resin is concentrated onto a much smaller volume of a Cs selective sorbent to achieve a significant radioactive waste volume reduction. Technical feasibility of the electrodialytic resin decontamination process has been demonstrated on a bench scale with a batch of simulated spent ion exchange resin and using potassium cobalt ferrocyanide as the Cs selective sorbent. A volume reduction factor between 10 and 17 has been estimated. The process appears to be economically attractive. Improvements in process economics can be expected from optimization of the process. Other possible applications of the EDRD process have been identified

  7. EPOXY RESINS TOUGHENED WITH CARBOXYL TERMINATED POLYETHERS

    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.

  8. Influence of spatial configurations on electromagnetic interference shielding of ordered mesoporous carbon/ordered mesoporous silica/silica composites

    Wang, Jiacheng; Zhou, Hu; Zhuang, Jiandong; Liu, Qian

    2013-01-01

    Ordered mesoporous carbons (OMCs), obtained by nanocasting using ordered mesoporous silicas (OMSs) as hard templates, exhibit unique arrangements of ordered regular nanopore/nanowire mesostructures. Here, we used nanocasting combined with hot-pressing to prepare 10 wt% OMC/OMS/SiO2 ternary composites possessing various carbon mesostructure configurations of different dimensionalities (1D isolated CS41 carbon nanowires, 2D hexagonal CMK-3 carbon, and 3D cubic CMK-1 carbon). The electric/dielec...

  9. Adsorption of octadecyltrichlorosilane on mesoporous SBA-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 m2/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 (-CH3) and methylene (-CH2) 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

  10. Adsorption of octadecyltrichlorosilane on mesoporous SBA-15

    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.

  11. Stabilization of mesoporous nanocrystalline zirconia with Laponite

    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.

  12. Solidification of ion exchange resin wastes

    Solidification media investigated included portland type I, portland type III and high alumina cements, a proprietary gypsum-based polymer modified cement, and a vinyl ester-styrene thermosetting plastic. Samples formulated with hydraulic cement were analyzed to investigate the effects of resin type, resin loading, waste-to-cement ratio, and water-to-cement ratio. The solidification of cation resin wastes with portland cement was characterized by excessive swelling and cracking of waste forms, both after curing and during immersion testing. Mixed bed resin waste formulations were limited by their cation component. Additives to improve the mechanical properties of portland cement-ion exchange resin waste forms were evaluated. High alumina cement formulations dislayed a resistance to deterioration of mechanical integrity during immersion testing, thus providing a significant advantage over portland cements for the solidification of resin wastes. Properties of cement-ion exchange resin waste forms were examined. An experiment was conducted to study the leachability of 137Cs, 85Sr, and 60Co from resins modified in portland type III and high alumina cements. The cumulative 137Cs fraction release was at least an order of magnitude greater than that of either 85Sr or 60Co. Release rates of 137Cs in high alumina cement were greater than those in portland III cement by a factor of two.Compressive strength and leach testing were conducted for resin wastes solidified with polymer-modified gypsum based cement. 137Cs, 85Sr, and 60Co fraction releases were about one, two and three orders of magnitude higher, respectively, than in equivalent portland type III cement formulations. As much as 28.6 wt % dry ion exchange resin was successfully solidified using vinyl ester-styrene compared with a maximum of 25 wt % in both portland and gypsum-based cement

  13. Single crystal particles of a mesoporous mixed transition metal oxide with a wormhole structure.

    Lee, B; Lu, D; Kondo, J N; Domen, K

    2001-10-21

    A new type of mesoporous mixed transition metal oxide of Nb and Ta (NbTa-TIT-1) has been prepared through a two-step calcination, which consists of single crystal particles with wormhole mesoporous structure. PMID:12240191

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

    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.

  15. Gyroidal mesoporous multifunctional nanocomposites via atomic layer deposition

    Werner, Jörg G.; Scherer, Maik R. J.; Steiner, Ullrich; Wiesner, Ulrich

    2014-07-01

    We demonstrate the preparation of rationally designed, multifunctional, monolithic and periodically ordered mesoporous core-shell nanocomposites with tunable structural characteristics. Three-dimensionally (3D) co-continuous gyroidal mesoporous polymer monoliths are fabricated from a solution-based triblock terpolymer-resol co-assembly and used as the functional templates for the fabrication of free-standing core-shell carbon-titania composites using atomic layer deposition (ALD). The deposition depth into the torturous gyroidal nanonetwork is investigated as a function of ALD conditions and the resulting composites are submitted to different thermal treatments. Results suggest that ALD can homogenously coat mesoporous templates with well defined pore sizes below 50 nm and thicknesses above 10 μm. Structural tunability like titania shell thickness and pore size control is demonstrated. The ordered nanocomposites exhibit triple functionality; a 3D continuous conductive carbon core that is coated with a crystalline titania shell that in turn is in contact with a 3D continuous mesopore network in a compact monolithic architecture. This materials design is of interest for applications including energy conversion and storage. Gyroidal mesoporous titania monoliths can be obtained through simultaneous titania crystallization and template removal in air.We demonstrate the preparation of rationally designed, multifunctional, monolithic and periodically ordered mesoporous core-shell nanocomposites with tunable structural characteristics. Three-dimensionally (3D) co-continuous gyroidal mesoporous polymer monoliths are fabricated from a solution-based triblock terpolymer-resol co-assembly and used as the functional templates for the fabrication of free-standing core-shell carbon-titania composites using atomic layer deposition (ALD). The deposition depth into the torturous gyroidal nanonetwork is investigated as a function of ALD conditions and the resulting composites are

  16. Two-dimensional mesoporous materials: From fragile coatings to flexible membranes

    Zheng-Long Yang; Jiao-Li Li; Cheng-Liang Zhang; Yun-Feng Lu; Zhen-Zhong Yang

    2013-01-01

    This paper reviews the progress of two-dimensional mesoporous materials including their synthesis strategy,mesostructure,composition,surface property,flexibility,and potential applications.During the past two decades,research on two-dimensional mesoporous materials has experienced an evolution from fragile coatings to flexible membranes.Aiming at practical applications,it is significant to support mesoporous materials with proper matrices for example porous membranes especially flexible ones to form mesoporous composite membranes with designed pore size and chemistry.

  17. Template method synthesis of mesoporous carbon spheres and its applications as supercapacitors

    Wilgosz, Karolina; Chen, Xuecheng; Kierzek, Krzysztof; Machnikowski, Jacek; Kalenczuk, Ryszard J.; Mijowska, Ewa

    2012-01-01

    Mesoporous carbon spheres (MCS) have been fabricated from structured mesoporous silica sphere using chemical vapor deposition (CVD) with ethylene as a carbon feedstock. The mesoporous carbon spheres have a high specific surface area of 666.8 m2/g and good electrochemical properties. The mechanism of formation mesoporous carbon spheres (carbon spheres) is investigated. The important thing is a surfactant hexadecyl trimethyl ammonium bromide (CTAB), which accelerates the process of carbon depos...

  18. Decomposing method for ion exchange resin

    The present invention concerns a method of decomposing ion exchange resins generated in a nuclear power plant to carbon dioxide reliably in a short period of time. (1) The ion exchange resins are mixed with water, and then they are kept for a predetermined period of time in the presence of an inert gas at high temperature and high pressure exceeding the critical point of water to decompose the ion exchange resins. (2) The ion exchange resins is mixed with water, an oxidant is added and they are kept for a predetermined time in the presence of an inert gas at a high temperature and a high pressure exceeding a critical point of water of an inert gas at a high temperature to decompose the ion exchange resins. (3) An alkali or acid is added to ion exchange resins and water to control the hydrogen ion concentration in the solution and the ion exchange resins are decomposed in above-mentioned (1) or (2). Sodium hydroxide is used as the alkali and hydrochloric acid is used as the acid. In addition, oxygen, hydrogen peroxide or ozone is used as an oxidant. (I.S.)

  19. 21 CFR 175.270 - Poly(vinyl fluoride) resins.

    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... the purpose of this section, poly(vinyl fluoride) resins consist of basic resins produced by...

  20. Studies on cesium uptake by phenolic resins

    The selective removal of cesium by phenolic ion-exchange resins from highly salted alkaline radioactive solutions was studied. The resins were synthesized by alkaline polycondensation of phenol, resorcinol, catechol, and resorcinol-catechol mixture with formaldehyde and characterized for their moisture regain, ion-exchange (H+ → Na+) capacity, and distribution coefficient (KD) for cesium. The effects of open and sealed curing of the polymers on their properties were studied. The effect of Na+, NaOH, and Cs+ concentration on the uptake of cesium by resorcinol-formaldehyde resin was investigated, in particular. The chemical, thermal, and radiation stabilities of the polymers were also studied

  1. Epoxide resins for use at low temperatures

    A simple screening test is presented which permits the rapid evaluation of many epoxide resin systems, with a subsequent more detailed evaluation of those which performed well in the test. Several hundred resin systems were investigated including such variables as hardened ratios and blends, diluents, flexibilisers and modifiers, but considering only one expoxide resin, namely diglycidyl ether of Bisphenol A. The materials and results are detailed and conclusions formulated. Polymers used in low temperature applications should contain, wherever possible, reinforcement in the form of glass fabrics, rovings or chopped strands. Further work is planned to assess the performance of these materials when used with fillers and in laminates in fatigue situations

  2. Luminous Efficient Compositions Based on Epoxy Resin

    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.

  3. Hydraulic Permeability of Resorcinol-Formaldehyde Resin

    An ion exchange process using spherical resorcinol-formaldehyde (RF) resin is the baseline process for removing cesium from the dissolved salt solution in the high-level waste tanks at the Hanford Site, using large scale columns as part of the Waste Treatment Plant (WTP). The RF resin is also being evaluated for use in the proposed small column ion exchange (SCIX) system, which is an alternative treatment option at Hanford and at the Savannah River Site (SRS). A recirculating test loop with a small ion exchange column was used to measure the effect of oxygen uptake and radiation exposure on the permeability of a packed bed of the RF resin. The lab-scale column was designed to be prototypic of the proposed Hanford columns at the WTP. Although the test equipment was designed to model the Hanford ion exchange columns, the data on changes in the hydraulic permeability of the resin will also be valuable for determining potential pressure drops through the proposed SCIX system. The superficial fluid velocity in the lab-scale test (3.4-5.7 cm/s) was much higher than is planned for the full-scale Hanford columns to generate the maximum pressure drop expected in those columns (9.7 psig). The frictional drag from this high velocity produced forces on the resin in the lab-scale tests that matched the design basis of the full-scale Hanford column. Any changes in the resin caused by the radiation exposure and oxygen uptake were monitored by measuring the pressure drop through the lab-scale column and the physical properties of the resin. Three hydraulic test runs were completed, the first using fresh RF resin at 25 C, the second using irradiated resin at 25 C, and the third using irradiated resin at 45 C. A Hanford AP-101 simulant solution was recirculated through a test column containing 500 mL of Na-form RF resin. Known amounts of oxygen were introduced into the primary recirculation loop by saturating measured volumes of the simulant solution with oxygen and reintroducing

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

    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 29Si magic angle spinning nuclear magnetic resonance (29Si 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 N2 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 H2O 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

  5. Sorption of dissolved organics from aqueous solution by polystrene resins. I. Resin characterization and sorption equilibrium

    Cornel, P.; Sontheimer, H.

    1986-01-01

    The results of sorption equilibrium studies indicate that adsorption is only one of the three mechanisms involved in removing organics from aqueous solution by polystyrene resins. The other two mechanisms are associated with the resin's capability to incorporate organics into their polymer matrix while swelling. To describe the overall sorption behavior, it is not sufficient to characterize the resin structure by estimating pore size distribution and internal surface area of the dry polymers. The amount of swelling in different organic solvents must also be evaluated as an important structural parameter of polystyrene resins. The role of the different mechanisms depends on both the resin structure and the physical and chemical properties of the solute. The solute's affinity for the polystyrene surface can be correlated with the solute's benzene-water partition coefficient. A heuristic model is presented which relates the sorption capacity to both the resin and solute properties.

  6. Method of decomposing radioactive spent ion exchange resins

    Purpose: To improve the decomposability of spent ion exchange resins such as anionic resins, anionic - cationic mixed resins or the likes issued from nuclear power plants. Method: Spent ion exchange resins containing radioactive materials are decomposed by hydrogen peroxide. In this case, anionic exchange resins or mixture of anionic exchange resins and cationic exchange resins are decomposed by using bivalent or trivalent iron ions coexistent with sulfate groups in excess of the amount corresponding to the molar amount of bivalent or trivalent iron ions as a catalyst. Since the anionic exchange resins or the mixture of the anionic exchange resins and cationic resins are decomposed substantially completely, the amount of residue after the decomposition is reduced and the volume-reducing property of the radioactive wastes can be improved to facilitate the solidifying treatment. (Moriyama, K.)

  7. The encapsulation of spent ion-exchange resins in an epoxide resin

    Inorganic and organic IX resins have been incorporated into a water-tolerant epoxide resin system. The effect of γ-irradiation to 5 x 109 rads on the mechanical properties of samples containing wet IX resins has been investigated. It was found that although there is a marked embrittlement of the epoxide matrix, useful mechanical properties are retained up to this dose. Gas evolution studies under irradiation and thermogravimetric analyses have also been carried out. (author)

  8. Shear bond strength between alumina substrate and prosthodontic resin composites with various adhesive resin systems

    AlJehani, Yousef A.; Baskaradoss, Jagan K; Geevarghese, Amrita; AlShehry, Marey A; Pekka K. Vallittu

    2015-01-01

    Background With the increase in demand for cosmetics and esthetics, resin composite restorations and all-ceramic restorations have become an important treatment alternative. Taking into consideration the large number of prosthodontic and adhesive resins currently available, the strength and durability of these materials needs to be evaluated. This laboratory study presents the shear bond strengths of a range of veneering resin composites bonded to all-ceramic core material using different adh...

  9. Hydraulic Permeability of Resorcinol-Formaldehyde Resin

    Taylor, Paul Allen [ORNL

    2010-01-01

    An ion exchange process using spherical resorcinol-formaldehyde (RF) resin is the baseline process for removing cesium from the dissolved salt solution in the high-level waste tanks at the Hanford Site, using large scale columns as part of the Waste Treatment Plant (WTP). The RF resin is also being evaluated for use in the proposed small column ion exchange (SCIX) system, which is an alternative treatment option at Hanford and at the Savannah River Site (SRS). A recirculating test loop with a small ion exchange column was used to measure the effect of oxygen uptake and radiation exposure on the permeability of a packed bed of the RF resin. The lab-scale column was designed to be prototypic of the proposed Hanford columns at the WTP. Although the test equipment was designed to model the Hanford ion exchange columns, the data on changes in the hydraulic permeability of the resin will also be valuable for determining potential pressure drops through the proposed SCIX system. The superficial fluid velocity in the lab-scale test (3.4-5.7 cm/s) was much higher than is planned for the full-scale Hanford columns to generate the maximum pressure drop expected in those columns (9.7 psig). The frictional drag from this high velocity produced forces on the resin in the lab-scale tests that matched the design basis of the full-scale Hanford column. Any changes in the resin caused by the radiation exposure and oxygen uptake were monitored by measuring the pressure drop through the lab-scale column and the physical properties of the resin. Three hydraulic test runs were completed, the first using fresh RF resin at 25 C, the second using irradiated resin at 25 C, and the third using irradiated resin at 45 C. A Hanford AP-101 simulant solution was recirculated through a test column containing 500 mL of Na-form RF resin. Known amounts of oxygen were introduced into the primary recirculation loop by saturating measured volumes of the simulant solution with oxygen and reintroducing

  10. 5-year clinical performance of resin composite versus resin modified glass ionomer restorative system in non-carious cervical lesions

    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....

  11. Nanostructured mesoporous tungsten oxide for gas sensor applications

    Rossinyol, Emma; Arbiol, Jordi; Marsal, Andreu; Peiro, Francesca; Cornet, Albert; Morante, Joan Ramon; Solovyov, Leonid A.; Tian, Bozhi; Tu, Bo; Zhao, Dongyuan

    2005-06-01

    Due to their simple implementation, low cost and good reliability for real-time control systems, semiconductor gas sensors offer good advantages with respect to other gas sensor devices. As gas adsorption is a surface effect, one of the most important parameter to tailor the sensitivity of the sensor material is to increase the surface area. For these propose, mesoporous oxides have been synthesized. Nanostructured mesoporous materials present a large and controllable pore size and high surface are. For the preparation of ordered nanostructure arrays, a hard template method has been used. This method presents some advantages when compared with a soft template method, especially in its specific topological stability, veracity, predictability and controllability. Moreover, with this hard template method we can obtain crystalline mesoporous oxides, with small particle size and high surface area. We have used SBA-15 (two-dimensional hexagonal structure) and KIT-6 (three-dimensional cubic structure) as a template for the synthesis of different crystalline mesoporous WO3 with a particle size about 8-10 nm and high surface area. Low angle XRD spectra show a high order mesoporous structure, without rests of silica template. TEM confirms that the silica host has been completely removed; therefore, the nanowires constitute a self-supported superlattice. HRTEM studies have been focused on the detailed structural characterization of these materials. Electrical characterization of the sensor response in front of NO2 has been performed. Some catalytic additives have been also introduced, in order to increase the sensitivity of the material.

  12. Photocatalytic activity of a hierarchically macro/mesoporous titania.

    Wang, Xinchen; Yu, Jimmy C; Ho, Chunman; Hou, Yidong; Fu, Xianzhi

    2005-03-15

    Light-harvesting macroporous channels have been successfully incorporated into a mesoporous TiO(2) framework to increase its photocatalytic activity. This bimodal porous material was characterized by X-ray diffractometry in both low-angle and wide-angle ranges, N(2) adsorption-desorption analysis, scanning and transmission electron microscopy, FT-IR, and diffuse reflectance spectroscopy. Ethylene photodegradation in gas-phase medium was employed as a probe reaction to evaluate the photocatalytic reactivity of the catalysts. The results reveal that sintering temperature significantly affects the structural stability and photocatalytic activity of titania. The catalyst which calcined at 350 degrees C possessed an intact macro/mesoporous structure and showed photocatalytic reactivity about 60% higher than that of commercial P25 titania. When the sample was calcined at 500 degrees C, the macroporous structure was retained but the mesoporous structure was partly destroyed. Further heating at temperatures above 600 degrees C destroyed both macro- and mesoporous structures, accompanied by a loss in photocatalytic activity. The high photocatalytic performance of the intact macro/mesoporous TiO(2) may be explained by the existence of macrochannels that increase photoabsorption efficiency and allow efficient diffusion of gaseous molecules. PMID:15752052

  13. Near-field radiative heat transfer in mesoporous alumina

    The thermal conductivity of mesoporous material has aroused the great interest of scholars due to its wide applications such as insulation, catalyst, etc. Mesoporous alumina substrate consists of uniformly distributed, unconnected cylindrical pores. Near-field radiative heat transfer cannot be ignored, when the diameters of the pores are less than the characteristic wavelength of thermal radiation. In this paper, near-field radiation across a cylindrical pore is simulated by employing the fluctuation dissipation theorem and Green function. Such factors as the diameter of the pore, and the temperature of the material are further analyzed. The research results show that the radiative heat transfer on a mesoscale is 2∼4 orders higher than on a macroscale. The heat flux and equivalent thermal conductivity of radiation across a cylindrical pore decrease exponentially with pore diameter increasing, while increase with temperature increasing. The calculated equivalent thermal conductivity of radiation is further developed to modify the thermal conductivity of the mesoporous alumina. The combined thermal conductivity of the mesoporous alumina is obtained by using porosity weighted dilute medium and compared with the measurement. The combined thermal conductivity of mesoporous silica decreases gradually with pore diameter increasing, while increases smoothly with temperature increasing, which is in good agreement with the experimental data. The larger the porosity, the more significant the near-field effect is, which cannot be ignored. (paper)

  14. Mesoporous materials used in medicine and environmental applications.

    Gunduz, Oguzhan; Yetmez, Mehmet; Sonmez, Maria; Georgescu, Mihai; Alexandrescu, Laura; Ficai, Anton; Ficai, Denisa; Andronescu, Ecaterina

    2015-01-01

    Mesoporous materials synthesized in the presence of templates, are commonly used for environment and medical applications. Due to the properties it holds, mesoporous silica nanoparticles is an excellent material for use in medical field, biomaterials, active principles delivery systems, enzyme immobilization and imaging. Their structure allows embedding large and small molecules, DNA adsorption and genetic transfer. Using mesoporous silica nanoparticles for delivery of bioactive molecules can protect them against degradation under physiological conditions, allow controlled drugs release and minimize side effects on healthy tissues. Cellular tests performed on mesoporous silica nanoparticles demonstrate that MSN's cytotoxicity is dependent on the size and concentration and suggests the use of larger size nanoparticles is optimal for medical applications. Mesoporous materials possess high biological compatibility, are non-toxic and can be easily modified by functionalizing the surface or inside the pores by grafting or co-condensation method. The structure, composition and pores size of this material can be optimized during synthesis by varying the stoichiometric reactants, reaction conditions, nature of the template's molecules or by functionalization method. PMID:25877095

  15. Advanced cement solidification technique for spent resins

    In the past 40 years, the nuclear facilities of China Institute of Atomic Energy (CIAE) produced an amount of radioactive organic resins, a kind of problematic stream in nuclear industry. As these facilities were stepping into decommissioning, the treatment of the spent organic resins was put on the agenda. The various routes for spent resin treatment such as incineration, advanced oxidation, cement immobilization, etc, were considered. Each method has its advantages and disadvantages when applied in the treatment of spent resins. Since the quantities of the spent organic resins were relatively small and an experience with variety of cementation processes existed in CIAE, predominately for immobilization of the evaporated concentrates, the option of direct encapsulation of the spent organic resins into cementitious materials was adopted in 2003, as a preferred method from the point of view of saving the on the cost of the disposal. In order to realize the end goal, the main work consisted of: the survey of the source terms; cementitious material formula investigation; and the process development. This work, which was undertaken in the following years, is addressed as follows. Source terms of the spent resins in CIAE were to be made clear firstly. The results showed that a total of 24-29 m3 of spent resins was generated and accumulated in the past 40 years. Spent resin arose from two research reactors (heavy water reactor and light water reactor), and from the waste management plant. The amount of the spent resins from the heavy water reactor was 1m3 or so, but its radioactive concentration was high to ∼108-∼109Bq/m3. Two kinds of cements, ASC and OPC cement were selected next, as the solidifying matrix to be investigated. A mixture surface response approach was employed to design experiment and interpret data. In comparison, ASC was superior to OPC cement and it displayed preferable performances to encapsulate spent resins. The optimum formulation is:1) resin

  16. Phenolic Resin Sector Enters New Stage

    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.

  17. Epoxide resins for use at low temperatures

    This chapter reports on the development and characterization of a number of unfilled epoxide resin systems offering improved resistance to thermal shock. Points out that the low temperature physical properties of cured resin systems are little changed by formulation variables. Finds that it is during cool down from room temperature that these newly developed resin systems demonstrate their ability to absorb the strains induced by differential thermal contraction. Concludes that the new epoxide resin systems demonstrate excellent resistance to thermal shock and have impregnation characteristics suitable for the preparation of fiber reinforced composites by vacuum impregnation or by wet lay up procedures. Notes that their improved resistance to thermal shock allows them to be used in situations where some inhomogeneity of reinforcement is unavoidable or where large temperature gradients may be present. Recommends that polymers used in low temperature applications should contain, wherever possible, reinforcement in the form of glass fabrics, rovings or chopped strands

  18. Improved high-temperature resistant matrix resins

    Green, H. E.; Chang, G. E.; Wright, W. F.; Ueda, K.; Orell, M. K.

    1989-01-01

    A study was performed with the objective of developing matrix resins that exhibit improved thermo-oxidative stability over state-of-the-art high temperature resins for use at temperatures up to 644 K (700 F) and air pressures up to 0.7 MPa (100 psia). The work was based upon a TRW discovered family of polyimides currently licensed to and marketed by Ethyl Corporation as EYMYD(R) resins. The approach investigated to provide improved thermo-oxidative properties was to use halogenated derivatives of the diamine, 2, 2-bis (4-(4-aminophenoxy)phenyl) hexafluoropropane (4-BDAF). Polyimide neat resins and Celion(R) 12,000 composites prepared from fluorine substituted 4-BDAF demonstrated unexpectedly lower glass transition temperatures (Tg) and thermo-oxidative stabilities than the baseline 4-BDAF/PMDA polymer.

  19. Cycloaliphatic epoxide resins for cationic UV - cure

    This paper introduces the cyclo - aliphatic epoxide resins used for the various applications of radiation curing and their comparison with acrylate chemistry. Radiation curable coatings and inks are pre - dominantly based on acrylate chemistry but over the last few years, cationic chemistry has emerged successfully with the unique properties inherent with cyclo - aliphatic epoxide ring structures. Wide variety of cationic resins and diluents, the formulation techniques to achieve the desired properties greatly contributes to the advancement of UV - curing technology

  20. Development of Polymer Resins using Neural Networks

    Fernandes Fabiano A. N.; Lona Liliane M. F.

    2002-01-01

    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 ...

  1. Volumetric polymerization shrinkage of contemporary composite resins

    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.

  2. Synthesis of mesoporous silica microsphere from dual surfactant

    Venkatathri Narayanan

    2008-12-01

    Full Text Available A new procedure is reported to synthesis mesoporous silica micro sphere for the first time. In these method two surfactants namely Span 80 and Tween 80 were used. Small angle X ray diffraction and N2 adsorption analysis shows the synthesized material has mesoporous property. The material has spherical morphology with 1-10 µm particle size. Beside the material found to have microcapsule property as observed from the Transmission electron microscopy. The Fourier transform Infrared spectroscopic analysis reveals that the materials are similar to other mesoporous materials. We also encapsulated an UV-absorber Ibuprofen inside the microcapsule, by mixing it before the synthesis. This shows a possibility of the materials in cosmetic applications.

  3. Synthesis and Characterization of Mesoporous Titanium Dioxide Spheres

    GULI Mi-na; CHEN Yu-ning; LI Xiao-tian

    2011-01-01

    Mesoporous titanium dioxide spheres were synthesized by a convenient solvothermal method at room temperature with tetraethyl titanate as a precursor. Investigation by means of X-ray di ffraction(XRD), transmission electron microscopy(TEM), scanning electron microscopy(SEM), and N2 adsorption-desorption isotherms confirms that the sample has a mesostructure with a higher specific surface area and shows that the mesoporous TiO2 spheres have a diameter of 2 μm, the average pore size is about 5.9 nm, and the BET surface area and specific pore volume are about 236 m2/g and 2.116 cm3/g, respectively. The anatase and ruffle mesoporous TiO2 spheres calcined at 700 C show much better photocatalytic activity than the samples calcined at other temperatures and is comparable to an uncaicined sample in the photodegradation of Methyl Blue(MB) under the UV irradiation.

  4. Mesoporous materials for energy conversion and storage devices

    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.

  5. Selective SERS Sensing Modulated by Functionalized Mesoporous Films.

    López-Puente, Vanesa; Angelomé, Paula C; Soler-Illia, Galo J A A; Liz-Marzán, Luis M

    2015-11-25

    A hybrid material comprising metal nanoparticles embedded in functionalized mesoporous thin films was constructed, and its use as a selective SERS-based sensor was demonstrated. The presence of specific functional groups in the pore network allows control over the surface chemistry of the pores, tuning the selectivity for specific molecules. Amino-functionalized hybrid mesoporous thin films were used in a proof of concept experiment, to discern the presence of methylene blue (MB) in mixtures with acid blue (AB), with no need for any sample pretreatment step. Selective detection of MB was possible through entrapment of AB in the mesoporous matrix, based on its high affinity for amino groups. The sensor selectivity can be tuned by varying the solution pH, rendering a pH responsive surface and thus, selective SERS-based sensing. The developed sensors allow specific detection of molecules in complex matrixes. PMID:26536368

  6. Electrochemical Hydrogen Storage in a Highly Ordered Mesoporous Carbon

    Dan eLiu

    2014-10-01

    Full Text Available A highly order mesoporous carbon has been synthesized through a strongly acidic, aqueous cooperative assembly route. The structure and morphology of the carbon material were investigated using TEM, SEM and nitrogen adsorption-desorption isotherms. The carbon was proven to be meso-structural and consisted of graphitic micro-domain with larger interlayer space. AC impedance and electrochemical measurements reveal that the synthesized highly ordered mesoporous carbon exhibits a promoted electrochemical hydrogen insertion process and improved capacitance and hydrogen storage stability. The meso-structure and enlarged interlayer distance within the highly ordered mesoporous carbon are suggested as possible causes for the enhancement in hydrogen storage. Both hydrogen capacity in the carbon and mass diffusion within the matrix were improved.

  7. Syntheses and applications of periodic mesoporous organosilica nanoparticles

    Croissant, Jonas G.; Cattoën, Xavier; Wong Chi Man, Michel; Durand, Jean-Olivier; Khashab, Niveen M.

    2015-12-01

    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.

  8. Actinide sequestration using self-assembled monolayers on mesoporous supports.

    Fryxell, Glen E; Lin, Yuehe; Fiskum, Sandy; Birnbaum, Jerome C; Wu, Hong; Kemner, Ken; Kelly, Shelley

    2005-03-01

    Surfactant templated synthesis of mesoporous ceramics provides a versatile foundation upon which to create high efficiency environmental sorbents. These nanoporous ceramic oxides condense a huge amount of surface area into a very small volume. The ceramic oxide interface is receptive to surface functionalization through molecular self-assembly. The marriage of mesoporous ceramics with self-assembled monolayer chemistry creates a powerful new class of environmental sorbent materials called self-assembled monolayers on mesoporous supports (SAMMS). These SAMMS materials are highly efficient sorbents whose interfacial chemistry can be fine-tuned to selectively sequester a specific target species, such as heavy metals, tetrahedral oxometalate anions, and radionuclides. Details addressing the design, synthesis, and characterization of SAMMS materials specifically designed to sequester actinides, of central importance to the environmental cleanup necessary after 40 years of weapons-grade plutonium production, as well as evaluation of their binding affinities and kinetics are presented. PMID:15787373

  9. Preliminary Synthesis and Characterization of Mesoporous Nanocrystalline Zirconia

    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.

  10. Adsorption of vitamin E on mesoporous titania nanocrystals

    Tri-block nonionic surfactant and titanium chloride were used as starting materials for the synthesis of mesoporous titania nanocrystallite powders. The main objective of the present study was to examine the synthesis of mesoporous titania nanocrystals and the adsorption of vitamin E on those nanocrystals using X-ray diffraction (XRD), transmission electron microscopy, and nitrogen adsorption and desorption isotherms. When the calcination temperature was increased to 300 oC, the reflection peaks in the XRD pattern indicated the presence of an anatase phase. The crystallinity of the nanocrystallites increased from 80% to 98.6% with increasing calcination temperature from 465 oC to 500 oC. The N2 adsorption data and XRD data taken after vitamin E adsorption revealed that the vitamin E molecules were adsorbed in the mesopores of the titania nanocrystals.

  11. Adsorption of vitamin E on mesoporous titania nanocrystals

    Shih, C.J., E-mail: cjshih@kmu.edu.tw [Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Lin, C.T.; Wu, S.M. [School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China)

    2010-07-15

    Tri-block nonionic surfactant and titanium chloride were used as starting materials for the synthesis of mesoporous titania nanocrystallite powders. The main objective of the present study was to examine the synthesis of mesoporous titania nanocrystals and the adsorption of vitamin E on those nanocrystals using X-ray diffraction (XRD), transmission electron microscopy, and nitrogen adsorption and desorption isotherms. When the calcination temperature was increased to 300 {sup o}C, the reflection peaks in the XRD pattern indicated the presence of an anatase phase. The crystallinity of the nanocrystallites increased from 80% to 98.6% with increasing calcination temperature from 465 {sup o}C to 500 {sup o}C. The N{sub 2} adsorption data and XRD data taken after vitamin E adsorption revealed that the vitamin E molecules were adsorbed in the mesopores of the titania nanocrystals.

  12. Highly Aminated Mesoporous Silica Nanoparticles with Cubic Pore Structure

    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.

  13. Confined Polymerization in Highly Ordered Mesoporous Organosilicas.

    Comotti, Angiolina; Bracco, Silvia; Beretta, Mario; Perego, Jacopo; Gemmi, Mauro; Sozzani, Piero

    2015-12-01

    Hybrid mesoporous organosilica exhibiting crystal-like order in the walls provided an ideal channel reaction vessel for the confined polymerization of acrylonitrile (PAN). The resulting high-molecular-mass PAN fills the channels at high yield and forms an ordered nanostructure of polymer nanobundles enclosed into the hybrid matrix. The in situ thermal transformation of PAN into rigid polyconjugated and, eventually, into condensed polyaromatic carbon nanofibers, retains the periodic architecture. Simultaneously, the matrix evolves showing the fusion of the p-phenylene rings and the cleavage of carbonsilicon bonds: this gives rise to graphitic-carbon/silica nanocomposites containing hyper-oxydrylated silica nanophases. Interestingly, the 3D hexagonal mesostructure survives in the carbonaceous material. The exploitation of porous materials of high capacity and a hybrid nature, for polymerization in the confined state, followed by high temperature treatments, allowed us to achieve unique and precisely fabricated nanostructures, thus paving the way for the construction of fine-tuned electronic and light-harvesting materials. PMID:26559381

  14. Zirconia-silica based mesoporous desulfurization adsorbents

    Palomino, Jessica M.; Tran, Dat T.; Kareh, Ana R.; Miller, Christopher A.; Gardner, Joshua M. V.; Dong, Hong; Oliver, Scott R. J.

    2015-03-01

    We report a series of mesoporous silicate sorbent materials templated by long-chain primary alkylamines that display record level of desulfurization of the jet fuel JP-8. Pure silica frameworks and those with a Si:Zr synthesis molar ratio ranging from 44:1 to 11:1 were investigated. The optimum sorbent was identified as dodecylamine-templated silica-zirconia synthesized from a gel with Si:Zr molar ratio of 15:1. With an optimized silver loading of 11 wt.%, a saturation adsorption capacity of 39.4 mgS g-1 and a silver efficiency of 1.21 molS mol Ag-1 were observed for JP-8. This sorbent displayed exceptional regenerability, maintaining 86% of its initial capacity in model fuel after solvent regeneration with diethyl ether. Low-cost, portable and reusable sorbents for the desulfurization of JP-8 jet fuel are needed to make solid oxide fuel cells (SOFCs) a reality for military power needs. SOFCs require ultra-low sulfur content fuel, which traditional desulfurization methods cannot achieve.

  15. Optical and electronic loss analysis of mesoporous solar cells

    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.

  16. Functionalized periodic mesoporous organosilicas: Hierarchical and chiral materials

    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.

  17. Monolithic Gyroidal Mesoporous Mixed Titanium–Niobium Nitrides

    2015-01-01

    Mesoporous transition metal nitrides are interesting materials for energy conversion and storage applications due to their conductivity and durability. We present ordered mixed titanium–niobium (8:2, 1:1) nitrides with gyroidal network structures synthesized from triblock terpolymer structure-directed mixed oxides. The materials retain both macroscopic integrity and mesoscale ordering despite heat treatment up to 600 °C, without a rigid carbon framework as a support. Furthermore, the gyroidal lattice parameters were varied by changing polymer molar mass. This synthesis strategy may prove useful in generating a variety of monolithic ordered mesoporous mixed oxides and nitrides for electrode and catalyst materials. PMID:25122534

  18. Mesoporous zeolite single crystals for catalytic hydrocarbon conversion

    Schmidt, I.; Christensen, C.H.; Hasselriis, Peter; Kustova, Marina; Nielsen, Michael Brorson; Dahl, Søren; Johannsen, K.; Christensen, Claus H.

    , 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....

  19. Exploring Mass Transfer in Mesoporous Zeolites by NMR Diffusometry

    Ryong Ryoo

    2012-04-01

    Full Text Available With the advent of mesoporous zeolites, the exploration of their transport properties has become a task of primary importance for the auspicious application of such materials in separation technology and heterogeneous catalysis. After reviewing the potential of the pulsed field gradient method of NMR (PFG NMR for this purpose in general, in a case study using a specially prepared mesoporous zeolite NaCaA as a host system and propane as a guest molecule, examples of the attainable information are provided.

  20. Simple Preparation of Novel Metal-Containing Mesoporous Starches

    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.

  1. Electric Field-Responsive Mesoporous Suspensions: A Review

    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.

  2. Macroporous silica–alumina composites with mesoporous walls

    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.

  3. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments

    Adilson Yoshio Furuse

    2007-12-01

    Full Text Available The purpose of this study was to investigate the effect of different surface treatments on shear bond strength of saliva-contaminated resin-resin interfaces. Flat resin surfaces were fabricated. In the control group, no contamination or surface treatment was performed. The resin surfaces of the experimental groups were contaminated with saliva and air-dried, and then submitted to: (G1 rinsing with water and drying; (G2 application of an adhesive system; (G3 rinsing and drying, abrasion with finishing disks, etching and application of adhesive system; (G4 rinsing and drying, etching, application of silane and adhesive system. Resin cylinders were placed over the treated surfaces. The specimens were stored in water or ethanol. Shear bond strength tests were performed and the mode of failure was evaluated. Data were submitted to two-way ANOVA and Dunnett T3 test. Contamination of resin-resin interfaces with saliva significantly reduced shear strength, especially after prolonged storage (p<0.05. Similar values to the original bond strength were obtained after abrasion and application of adhesive (G3 or etching and application of silane and adhesive (G4. If contamination occurs, a surface treatment is required to guarantee an adequate interaction between the resin increments.

  4. Selection of Unsaturated Polyester Resins for Closed Resin Transfer Moulding Processes

    Leyla Y. Jaramillo-Zapata

    2012-06-01

    Full Text Available In this paper three commercial unsaturated polyester resins of wide use in Colombia are analyzed and it is evaluated the convenience of their use in resin transfer molding processes according to viscosity and reactivity criteria. The resin viscosities are compared between 15 and 50°C, in the same way as the reactivity by mean of the curing curves at room temperature, using catalyst at 1, 1.5 and 2%. In agreement with the results, it was determined that some resins are suitable for RTM process, because of their appropriate viscosity, consistent reactivity and curing velocity. These features are of great importance in the unsaturated polyester resin selection, according to conditions of closed mold processes.

  5. Tc-99 Ion Exchange Resin Testing

    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.

  6. Natural weathering studies of oil palm trunk lumber (OPTL) green polymer composites enhanced with oil palm shell (OPS) nanoparticles

    Islam, Md Nazrul; Dungani, Rudi; Abdul Khalil, HPS; Alwani, M Siti; Nadirah, WO Wan; Fizree, H Mohammad

    2013-01-01

    In this study, a green composite was produced from Oil Palm Trunk Lumber (OPTL) by impregnating oil palm shell (OPS) nanoparticles with formaldehyde resin. The changes of physical, mechanical and morphological properties of the OPS nanoparticles impregnated OPTL as a result of natural weathering was investigated. The OPS fibres were ground with a ball-mill for producing nanoparticles before being mixed with the phenol formaldehyde (PF) resin at a concentration of 1, 3, 5 and 10% w/w basis and...

  7. Resin flow monitoring in vacuum-assisted resin transfer molding using optical fiber distributed sensor

    Eum, Soohyun; Kageyama, Kazuro; Murayama, Hideaki; Ohsawa, Isamu; Uzawa, Kiyoshi; Kanai, Makoto; Igawa, Hirotaka

    2007-04-01

    In this study, we implemented resin flow monitoring by using an optical fiber sensor during vacuum assisted resin transfer molding (VaRTM).We employed optical frequency domain reflectometry (OFDR) and fiber Bragg grating (FBG) sensor for distributed sensing. Especially, long gauge FBGs (about 100mm) which are 10 times longer than an ordinary FBG were employed for more effective distributed sensing. A long gauge FBG was embedded in GFRP laminates, and other two ones were located out of laminate for wavelength reference and temperature compensation, respectively. During VaRTM, the embedded FBG could measure how the preform affected the sensor with vacuum pressure and resin was flowed into the preform. In this study, we intended to detect the gradient of compressive strain between impregnated part and umimpregnated one within long gauge FBG. If resin is infused to preform, compressive strain which is generated on FBG is released by volume of resin. We could get the wavelength shift due to the change of compressive strain along gauge length of FBG by using short-time Fourier transformation for signal acquired from FBG. Therefore, we could know the resin flow front with the gradient of compressive strain of FBG. In this study, we used silicon oil which has same viscosity with resin substitute for resin in order to reuse FBG. In order to monitor resin flow, the silicon oil was infused from one edge of preform, the silicon oil was flowed from right to left. Then, we made dry spot within gauge length by infusing silicon oil to both sides of preform to prove the ability of dry spot monitoring with FBG. We could monitor resin flow condition and dry spot formation successfully using by FBG based on OFDR.

  8. Hot dewatering and resin encapsulation of intermediate level radioactive waste

    The chemistry of the processes involved in the hot dewatering and encapsulation of alumino-ferric hydroxide floc in epoxide resin have been studied. Pretreatment of the floc to reduce resin attack and hydrolysis and to increase the dimensional stability of the solidified wasteform has been evaluated. It has been demonstrated that removal of ammonium nitrate from the floc and control of the residual water in the resin are important factors in ensuring dimensional stability of the solidified resin. Resin systems have been identified which, together with the appropriate waste pretreatment have successfully encapsulated a simulated magnox sludge producing a stable wasteform having mechanical and physical properties comparable with the basic resin. (author)

  9. Biocompatibility of polymethylmethacrylate resins used in dentistry.

    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. PMID:22454327

  10. Stabilizing parquet blocks with epoxy resin

    S.S. Glazkov

    2015-11-01

    Full Text Available While parquet blocks and panels from stabilized wood show much promise as finishing materials, their widespread use is limited by their low dimensional stability in variable-humidity environments. Existing solutions to stabilize the blocks have several disadvantages, including hard-to-find or toxic stabilizers. This is why this study discusses modifications of epoxy resin which has sufficient functionality for effective structuring. We analyzed the capillary-porous structure of different types of wood, and established the patterns associated with a reduction in the porosity or the specific volume of voids in pine, birch and oak. The basic characteristics of impregnating compositions indicating the high penetrative and structuring capabilities of epoxy resin have been discovered. It is shown that in addition to increasing the strength characteristics, there is a steady decline in water absorption and swelling with an increase in resin content in the wood. It has been found by the method of test fluids that curing the epoxy resin in the presence of hexamethylenediamine is accompanied by a decrease in the proportion of polar components in the total value of the surface tension. Oligomer molecules were shown to penentrate pine wood cells, providing a high moisture protection effect. The results suggest it is possible to use epoxy resin to modify parquet blocks and panels that would be used under variable humidity and high impact loads.

  11. Development of a heterogeneous laminating resin system

    Biermann, T. F.; Hopper, L. C.

    1985-01-01

    The factors which effect the impact resistance of laminating resin systems and yet retain equivalent performance with the conventional 450 K curing epoxy matrix systems in other areas were studied. Formulation work was conducted on two systems, an all-epoxy and an epoxy/bismaleimide, to gain fundamental information on the effect formulation changes have upon neat resin and composite properties. The all-epoxy work involved formulations with various amounts and combinations of eight different epoxy resins, four different hardeners, fifteen different toughening agents, a filler, and a catalyst. The epoxy/bismaleimide effort improved formulations with various amounts and combinations of nine different resins, four different hardeners, eight different toughening agents, four different catalysts, and a filler. When a formulation appeared to offer the proper combination of properties required for a laminating resin Celion 3K-70P fabric was prepregged. Initial screening tests on composites primarily involved Gardner type impact and measurement of short beam shear strengths under dry and hot/wet conditions.

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

    Nikola Ž. Knežević

    2014-06-01

    Full Text Available Core/shell nanoparticles, containing magnetic iron-oxide (maghemite core and mesoporous shell with radial porous structure, were prepared by dispersing magnetite nanoparticles and adding tetraethylorthosilicate to a basic aqueous solution containing structure-templating cetyltrimethylammonium bromide and a pore-swelling mesithylene. The material is characterized by SEM and TEM imaging, nitrogen sorption and powder X-ray diffraction. Distinctive features of the prepared material are its high surface area (959 m2/g, wide average pore diameter (12.4 nm and large pore volume (2.3 cm3/g. The material exhibits radial pore structure and the high angle XRD pattern characteristic for maghemite nanoparticles, which are obtained upon calcination of the magnetite-containing material. The observed properties of the prepared material may render the material applicable in separation, drug delivery, sensing and heterogeneous catalysis.

  13. Pore ordering in mesoporous matrices induced by different directing agents

    Putz, A.-M.; Cecilia, S.; Ianasi, C.; Dudás, Z.; Székely, N. K.; Plocek, Jiří; Sfarloaga, P.; Sacarescu, L.; Almásy, L.

    2015-01-01

    Roč. 22, č. 2 (2015), s. 321-331. ISSN 1380-2224 Institutional support: RVO:61388980 Keywords : Mesoporous silica * MCM-41 * Dodecyl-trimethyl ammonium bromide * Hexadecyl-trimethylammonium bromide Subject RIV: CA - Inorganic Chemistry Impact factor: 1.108, year: 2014

  14. Mesoporous molecular sieves as advanced supports for olefin metathesis catalysts

    Balcar, Hynek; Čejka, Jiří

    2013-01-01

    Roč. 257, 21-22 (2013), s. 3107-3124. ISSN 0010-8545 R&D Projects: GA AV ČR IAA400400805; GA ČR GBP106/12/G015 Institutional support: RVO:61388955 Keywords : Olefin metathesis * mesoporous molecular sieves * Heterogeneous catalysts Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 12.098, year: 2013

  15. Bifunctional mesoporous silicas with clearly distinguished localization of grafted groups

    Roik, N. V.; Belyakova, L. A.

    2013-12-01

    Bifunctional mesoporous silicas with clearly distinguished localization of grafted groups on the surface of particles and inside their pores were obtained by means of sol-gel synthesis with postsynthetic vapor-phase treatment in vacuum. It was found that the synthesized materials have the hexagonally ordered porous structure typical of MCM-41 type silica.

  16. Mesoporous carbon microspheres with high capacitive performances for supercapacitors

    Highlights: • Small mesopores-enriched porous carbon microspheres were easily synthesized. • Small mesopores offer high ion-accessible surface area and facilitated ion diffusion. • The porous carbon exhibited a high specific capacitance and a good power property. - Abstract: Novel small-mesopores-enriched porous carbon microspheres have been synthesized from carbonaceous polysaccharide microspheres, by using the associated lithium acetate treating and heat treating strategies. X-ray diffraction, scanning electron microscope, transmission electron microscopy and nitrogen adsorption-desorption techniques have been employed to investigate the as-prepared samples. The analysis results indicate that the porous carbon microspheres has a high specific surface area of 1163 m2 g−1 and a satisfactory small mesoporous texture (2∼5 nm), with the mean pore size of 3.24 nm and the pore volume ratio of 2∼5 nm pores up to 92%. The capacitive performances of the samples in 6 mol L−1 KOH aqueous electrolyte, have been tested by cyclic voltammetry, electrochemical impedance spectroscopy and charge-discharge techniques. A specific capacitance of 171.5 F/g is obtained for the porous carbon microspheres via charge-discharge at a current density of 1000 mA/g. It also displayed a very high cycle stability of 97.8%, compared with the initial capacitance, after 1000 cycles at the high current density of 1000 mA/g

  17. Mesoporous molecular sieves as supports for metathesis catalysts

    Balcar, Hynek; Čejka, Jiří

    Dordrecht : Springer, 2007, s. 151-166. ISBN 978-1-4020-6090-8 R&D Projects: GA AV ČR IAA4040411; GA ČR GA203/05/2194 Institutional research plan: CEZ:AV0Z40400503 Keywords : mesoporous molecular sieves * heterogeneous catalysts * olefin metathesis * metathesis polymerization Subject RIV: CF - Physical ; Theoretical Chemistry

  18. Solution Plasma Process for Template Removal in Mesoporous Silica Synthesis

    Pootawang, Panuphong; Saito, Nagahiro; Takai, Osamu

    2010-12-01

    The plasma discharge in aqueous solution was scientifically studied and applied to template removal in mesoporous silica synthesis. Highly dispersed spherical mesoporous silica particles were synthesized by the ternary surfactant system containing the Pluronic P123 copolymer (EO20PO69EO20), sodium dodecylbenzene sulfonate, and 1,1,2,2,3,3,4,4,4-nonafluoro-1-butane sulfonate, via the sol-gel method in acid solutions. The solution plasma process (SPP), instead of conventional thermal calcinations, was used to remove the template. The mechanism of the removal of the organic template occurred via oxidation by the hydroxyl radicals generated during discharge. The transformation of a mesopore structure from a disordered wormlike structure to a hexagonally arranged structure was observed by X-ray diffraction analysis and was confirmed by transmission electron microscopy. The results of the thermal analysis and functional group identification of mesoporous silica after SPP showed evidence of organic template removal. The surface area calculated using the Brunauer-Emmett-Teller (BET) theory and the mean pore diameter results could be used to evaluate the plasma efficiency, demonstrating that this method does not affect the pore size in the case of discharge in a solution of pH 3 compared with the results of thermal calcination. Hence, SPP was proved to be highly efficient for organic template removal, exhibiting short consumption time and less contamination.

  19. Chemistry on the inside: green chemistry in mesoporous materials

    MacQuarrie, D.J.

    2000-01-01

    An overview of the rapidly expanding area of tailored mesoporous solids is presented. The synthesis of a wide range of the materials is covered, both inorganically and organically modified. Their applications, in particular those relating to green chemistry, are also highlighted. Finally, potential future directions for these materials are discussed.

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

    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.

  1. Enhanced photocatalytic properties in well-ordered mesoporous WO3

    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.

  2. Synthesis of porous carbon/silica nanostructured microfiber with ultrahigh surface area

    Zhou, Dan; Dong, Yan; Cui, Liru; Lin, Huiming, E-mail: hiuminglin@gmail.com; Qu, Fengyu, E-mail: qufengyu2012@yahoo.cn, E-mail: qufengyu@hrbnu.edu.cn [Harbin Normal University, College of Chemistry and Chemical Engineering (China)

    2014-12-15

    Carbon/silica-nanostructured microfibers were synthesized via electrospinning method using phenol-formaldehyde resin and tetraethyl orthosilicate as carbon and silica precursor with triblock copolymer Pluronic P123 as soft template. The prepared samples show uniform microfiber structure with ∼1 μm in diameter and dozens of microns in length. Additionally, the mesopores in the material is about 2–6 nm. When the silica component was removed by HF, the porous carbon microfibers (PCMFs) were obtained. In addition, after the carbon/silica composites were calcined in air, the porous silica microfibers (PSiMFs) were obtained, revealing the converse porous nanostructure as PCMFs. It is a simple way to prepare PCMFs and PSiMFs with silica and carbon as the template to each other. Additionally, PCMFs possess an ultrahigh specific surface area (2,092 m{sup 2} g{sup −1}) and large pore volume. The electrochemical performance of the prepared PCMF material was investigated in 6.0 M KOH electrolyte. The PCMF electrode exhibits a high specific capacitance (252 F g{sup −1} at 0.5 A g{sup −1}). Then, superior cycling stability (97 % retention after 4,000 cycles) mainly is due to its unique nanostructure.

  3. Synthesis of porous carbon/silica nanostructured microfiber with ultrahigh surface area

    Carbon/silica-nanostructured microfibers were synthesized via electrospinning method using phenol-formaldehyde resin and tetraethyl orthosilicate as carbon and silica precursor with triblock copolymer Pluronic P123 as soft template. The prepared samples show uniform microfiber structure with ∼1 μm in diameter and dozens of microns in length. Additionally, the mesopores in the material is about 2–6 nm. When the silica component was removed by HF, the porous carbon microfibers (PCMFs) were obtained. In addition, after the carbon/silica composites were calcined in air, the porous silica microfibers (PSiMFs) were obtained, revealing the converse porous nanostructure as PCMFs. It is a simple way to prepare PCMFs and PSiMFs with silica and carbon as the template to each other. Additionally, PCMFs possess an ultrahigh specific surface area (2,092 m2 g−1) and large pore volume. The electrochemical performance of the prepared PCMF material was investigated in 6.0 M KOH electrolyte. The PCMF electrode exhibits a high specific capacitance (252 F g−1 at 0.5 A g−1). Then, superior cycling stability (97 % retention after 4,000 cycles) mainly is due to its unique nanostructure

  4. A magnetic mesoporous silica nanoparticle-based drug delivery system for photosensitive cooperative treatment of cancer with a mesopore-capping agent and mesopore-loaded drug

    Knežević, Nikola Ž.; Lin, Victor S.-Y.

    2013-01-01

    Lately, there has been a growing interest in anticancer therapy with a combination of different drugs that work by different mechanisms of action, which decreases the possibility that resistant cancer cells will develop. Herein we report on the development of a drug delivery system for photosensitive delivery of a known anticancer drug camptothecin along with cytotoxic cadmium sulfide nanoparticles from a magnetic drug nanocarrier. Core-shell nanoparticles consisting of magnetic iron-oxide-cores and mesoporous silica shells are synthesized with a high surface area (859 m2 g-1) and hexagonal packing of mesopores, which are 2.6 nm in diameter. The mesopores are loaded with anticancer drug camptothecin while entrances of the mesopores are blocked with 2-nitro-5-mercaptobenzyl alcohol functionalized CdS nanoparticles through a photocleavable carbamate linkage. Camptothecin release from this magnetic drug delivery system is successfully triggered upon irradiation with UV light, as measured by fluorescence spectroscopy. Photosensitive anticancer activity of the drug delivery system is monitored by viability studies on Chinese hamster ovarian cells. The treatment of cancer cells with drug loaded magnetic material leads to a decrease in viability of the cells due to the activity of capping CdS nanoparticles. Upon exposure to low power UV light (365 nm) the loaded camptothecin is released which induces additional decrease in viability of CHO cells. Hence, the capping CdS nanoparticles and loaded camptothecin exert a cooperative anticancer activity. Responsiveness to light irradiation and magnetic activity of the nanocarrier enable its potential application for selective targeted treatment of cancer.

  5. Immobilization of radioactive ion exchange resins in glass. Part I: Pretreatment of the resins

    Full Text: The ion exchange resins are used to retain the radionuclides that contaminate the water in primary and secondary circuits and storage pools of the Argentine nuclear reactors. Once used, this resins are an intermediate level waste. Due to the generated volume of resins during the reactor life, it is necessary to have a proper method for management and final disposal of these wastes. Up to now in National Atomic Energy Commission (CNEA), the most studied process is cementation. However, this method increases the waste volume and the final product has low compression hardness. The immobilization in glass of these wastes is attractive because of the volume reduction that could be attained and because of the well known durability of glass. In this work we prepared a mixed bed of resins, similar to those used in Argentina nuclear reactors. We use cesium as a simulant for the active elements present in the resins. Absorption of lithium and cesium was controlled by conductivity and/or ph measurements. The so charged resins were thermally decomposed. This process was studied by Dta/T G experiments. Some potentially problematic effects were founded (foam formation, particle explosion), regarding the possibility of immobilisation of the resins in glass by sintering. Finally, the calcination products were analyzed by Sem and X-ray diffraction. This analysis showed that lithium and cesium remain as sulfates. For this reason we decided to use those chemical compounds as simulant s of the calcination products in the following sintering experiments

  6. Immobilisation of ion exchange resins in cement

    Over the last seven years, Low Oxidation State Metal Ion reagents (LOMI) have been used to decontaminate the 100 MW(e) Steam Generating Heavy Water Ractor (SGHWR) at Winfrith. The use of these reagents has resulted in a dilute ionic solution containing activation products which are produced by corrosion of metallic components in the reactor. It has been demonstrated that the amount of activity in the solution can be reduced using organic ion exchanger resins. These resins consist of a cross linked polystyrene with sulphonic acid or quaternary ammonium function groups and can be successfully immobilised in blended cement systems. The formulation which has been developed is produced from a 9 to 1 blend of ground granulated blast furnace slag (BFS) and ordinary Portland cement (OPC) containing 28% ion exchange resin in the water saturated form. If 6% Microsilica is added to the blended cement the waste loading can be increased to 36 w/o. (author)

  7. Adsorption of plant phenols by polystyrene resins

    Akiyoshi Fukushima

    2014-02-01

    Full Text Available Adsorption of nine plant phenols by nine polystyrene ion-exchange resins was investigated in an experimental model system. The phenols were adsorbed by Amberlite CG-120 more efficiently than any other acidically charged resins tested in this study. They were also taken up by anion exchangers. Among them Dowex 1-X8 was found to show the strongest effect on the adsorption of the phenolic constituents applied. A comparison of the efficiency of plant phenol adsorption between two different types of the synthetic polymers revealed that the basically charged polystyrenes had more prefarable affinities for phenols than cation exchangers. For example, the ratio of the efficiency between Amberlite CG-120 and Dowex 1-X8 was roughly calculated to be 3:7 under the present experimental conditions. The adsorption rate of the test phenols was raised mostly by increasing the amount of the resins added, if they were mixed with effective polymers in the incubation model system.

  8. Development of Polymer Resins using Neural Networks

    Fernandes Fabiano A. N.

    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%.

  9. Aging in CTBN modified epoxy resin stocks

    The cause of degradation in the glass transition temperature (T/sub G/) of a partially crystallized polymer was investigated. Sample epoxy resin filled capacitors were cured at 900C for 24 hours, then stored at room atmospheric conditions. These showed typical degradation in T/sub G/ after storage for one month. One set of epoxy resin castings was stored at room atmosphere and another set was stored in a dry box at 0% relative humidity and 270C. The samples at room atmospheric conditions showed typical degradation in T/sub G/, while the T/sub G/ for those stored in the dry box increased. Further tests were then made on epoxy resin castings at various curing temperatures and times at both room atmosphere and 0% humidity. Resulting data indicated that absorption of moisture during storage was the predominant cause of T/sub G/ degradation, with stress relaxation another, though smaller, contributing factor

  10. Improved high temperature resistant matrix resins

    Chang, G. E.; Powell, S. H.; Jones, R. J.

    1983-01-01

    The objective was to develop organic matrix resins suitable for service at temperatures up to 644 K (700 F) and at air pressures up to 0.4 MPa (60 psia) for time durations of a minimum of 100 hours. Matrix resins capable of withstanding these extreme oxidative environmental conditions would lead to increased use of polymer matrix composites in aircraft engines and provide significant weight and cost savings. Six linear condensation, aromatic/heterocyclic polymers containing fluorinated and/or diphenyl linkages were synthesized. The thermo-oxidative stability of the resins was determined at 644 K and compressed air pressures up to 0.4 MPa. Two formulations, both containing perfluoroisopropylidene linkages in the polymer backbone structure, exhibited potential for 644 K service to meet the program objectives. Two other formulations could not be fabricated into compression molded zero defect specimens.

  11. Multifunctional mesoporous silica nanocomposite nanoparticles for theranostic applications.

    Lee, Ji Eun; Lee, Nohyun; Kim, Taeho; Kim, Jaeyun; Hyeon, Taeghwan

    2011-10-18

    Clever combinations of different types of functional nanostructured materials will enable the development of multifunctional nanomedical platforms for multimodal imaging or simultaneous diagnosis and therapy. Mesoporous silica nanoparticles (MSNs) possess unique structural features such as their large surface areas, tunable nanometer-scale pore sizes, and well-defined surface properties. Therefore, they are ideal platforms for constructing multifunctional materials that incorporate a variety of functional nanostructured materials. In this Account, we discuss recent progress by our group and other researchers in the design and fabrication of multifunctional nanocomposite nanoparticles based on mesoporous silica nanostructures for applications to simultaneous diagnosis and therapy. Versatile mesoporous silica-based nanocomposite nanoparticles were fabricated using various methods. Here, we highlight two synthetic approaches: the encapsulation of functional nanoparticles within a mesoporous silica shell and the assembly of nanoparticles on the surface of silica nanostructures. Various nanoparticles were encapsulated in MSNs using surfactants as both phase transfer agents and pore-generating templates. Using MSNs as a scaffold, functional components such as magnetic nanoparticles and fluorescent dyes have been integrated within these systems to generate multifunctional nanocomposite systems that maintain their individual functional characteristics. For example, uniform mesoporous dye-doped silica nanoparticles immobilized with multiple magnetite nanocrystals on their surfaces have been fabricated for their use as a vehicle capable of simultaneous magnetic resonance (MR) and fluorescence imaging and drug delivery. The resulting nanoparticle-incorporated MSNs were then tested in mice with tumors. These in vivo experiments revealed that these multifunctional nanocomposite nanoparticles were delivered to the tumor sites via passive targeting. These nanocomposite

  12. Oxidative nanopatterning of titanium generates mesoporous surfaces with antimicrobial properties

    Variola F

    2014-05-01

    Full Text Available Fabio Variola,1,2 Sylvia Francis Zalzal,3 Annie Leduc,3 Jean Barbeau,3 Antonio Nanci31Faculty of Engineering, Department of Mechanical Engineering, 2Faculty of Science, Department of Physics, University of Ottawa, Ottawa, ON, 3Faculty of Dental Medicine, Université de Montréal, Montreal, QC, CanadaAbstract: Mesoporous surfaces generated by oxidative nanopatterning have the capacity to selectively regulate cell behavior, but their impact on microorganisms has not yet been explored. The main objective of this study was to test the effects of such surfaces on the adherence of two common bacteria and one yeast strain that are responsible for nosocomial infections in clinical settings and biomedical applications. In addition, because surface characteristics are known to affect bacterial adhesion, we further characterized the physicochemical properties of the mesoporous surfaces. Focused ion beam (FIB was used to generate ultrathin sections for elemental analysis by energy-dispersive X-ray spectroscopy (EDS, nanobeam electron diffraction (NBED, and high-angle annular dark field (HAADF scanning transmission electron microscopy (STEM imaging. The adherence of Staphylococcus aureus, Escherichia coli and Candida albicans onto titanium disks with mesoporous and polished surfaces was compared. Disks with the two surfaces side-by-side were also used for direct visual comparison. Qualitative and quantitative results from this study indicate that bacterial adhesion is significantly hindered by the mesoporous surface. In addition, we provide evidence that it alters structural parameters of C. albicans that determine its invasiveness potential, suggesting that microorganisms can sense and respond to the mesoporous surface. Our findings demonstrate the efficiency of a simple chemical oxidative treatment in generating nanotextured surfaces with antimicrobial capacity with potential applications in the implant manufacturing industry and hospital setting

  13. Synthesis of mesoporous zeolite single crystals with cheap porogens

    Mesoporous zeolite (silicalite-1, ZSM-5, TS-1) single crystals have been successfully synthesized by adding soluble starch or sodium carboxymethyl cellulose (CMC) to a conventional zeolite synthesis system. The obtained samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen sorption analysis, 27Al magic angle spinning nuclear magnetic resonance (27Al MAS NMR), temperature-programmed desorption of ammonia (NH3-TPD) and ultraviolet-visible spectroscopy (UV-vis). The SEM images clearly show that all zeolite crystals possess the similar morphology with particle size of about 300 nm, the TEM images reveal that irregular intracrystal pores are randomly distributed in the whole crystal. 27Al MAS NMR spectra indicate that nearly all of the Al atoms are in tetrahedral co-ordination in ZSM-5, UV-vis spectra confirm that nearly all of titanium atoms are incorporated into the framework of TS-1. The catalytic activity of meso-ZSM-5 in acetalization of cyclohexanone and meso-TS-1 in hydroxylation of phenol was also studied. The synthesis method reported in this paper is cost-effective and environmental friendly, can be easily expended to prepare other hierarchical structured zeolites. - Graphical abstract: Mesoporous zeolite single crystals were synthesized by using cheap porogens as template. Highlights: → Mesoporous zeolite (silicalite-1, ZSM-5, TS-1) single crystals were synthesized. → Soluble starch or sodium carboxymethyl cellulose (CMC) was used as porogens. → The mesoporous zeolites had connected mesopores although closed pores existed. → Higher catalytic activities were obtained.

  14. Magnetic mesoporous materials for removal of environmental wastes

    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.

  15. Vitrification of spent ion exchange resin from Korean NPPs

    Spent resin is the main wet waste generated by nuclear power plants (NPPs). Vitrification is conceptually attractive because of the potential durability of the final product and the large volume reduction. The vitrification of spent resin from NPPs is examined. There is a large amount of sulfate in spent resin ash. However, the limited solubility of sulfate in glass resulted in the low waste loading of spent resin. High sulfate in glass led to the phase separation. Some well-developed glasses frits have been used to vitrify spent resin from Korean NPPs. The waste loading is less than 5 wt percent of resin ash. Spent resin also was added to the borate waste glasses, 20 g of dry resin could be vitrified in 100 g of borate waste glass without phase separation and final waste from has good durability. (author). 12 refs., 6 tabs

  16. Petroleum Resins: Separation, Character, and Role in Petroleum

    Andersen, Simon Ivar; Speight, James

    2001-01-01

    In petroleum science, the term resin generally implies material that has been eluted from various solid adsorbents, whereas the term maltenes (or petrolenes) indicates a mixture of the resins and oils obtained as filtrates from the asphaltene precipitation. Thus, after the asphaltenes are...... precipitated, adsorbents are added to the n-pentane solutions of the resins and oils, by which process the resins are adsorbed and subsequently recovered by the use of a more polar solvent, and the oils remain in solution. The resin fraction plays an important role in the stability of petroleum and prevents...... of the fact that the resin fraction is extremely important to the stability of petroleum, there is surprisingly little work reported on the characteristics of the resins. This article summarizes the work that has been carried out in determining the character and properties of the resin constituents...

  17. Petroleum Resins: Separation, Character, and Role in Petroleum

    Andersen, Simon Ivar; Speight, James

    In petroleum science, the term resin generally implies material that has been eluted from various solid adsorbents, whereas the term maltenes (or petrolenes) indicates a mixture of the resins and oils obtained as filtrates from the asphaltene precipitation. Thus, after the asphaltenes are...... precipitated, adsorbents are added to the n-pentane solutions of the resins and oils, by which process the resins are adsorbed and subsequently recovered by the use of a more polar solvent, and the oils remain in solution. The resin fraction plays an important role in the stability of petroleum and prevents...... of the fact that the resin fraction is extremely important to the stability of petroleum, there is surprisingly little work reported on the characteristics of the resins. This article summarizes the work that has been carried out in determining the character and properties of the resin constituents...

  18. Resin additive improves performance of high-temperature hydrocarbon lubricants

    Johnson, R. L.; Loomis, W. R.

    1971-01-01

    Paraffinic resins, in high temperature applications, improve strength of thin lubricant film in Hertzian contacts even though they do not increase bulk oil viscosity. Use of resin circumvents corrosivity and high volatility problems inherent with many chemical additives.

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

    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

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

    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 m2/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 fiber

  1. Preparation and Characterization of Cardanol Modified Sand Core%树脂催化腰果酚改性砂芯粘合剂的制备与表征

    刘颖; 王德堂; 李敢; 肖先举

    2015-01-01

    在邻苯酚甲醛树脂体系中引入具有长链烷基的取代酚——腰果酚,采用强碱性大孔阴离子交换树脂为催化剂进行改性.经试验研究,得到了较好的制备了腰果酚邻苯基苯酚甲醛树脂粘结剂的工艺条件.通过IR、DSC、TG等手段对腰果酚邻苯基苯酚甲醛树脂的结构、固化性能及耐热性进行了分析,结果表明,合成树脂结构中含有腰果酚,该树脂耐热性优于邻苯基苯酚甲醛树脂,具有优异的韧性及粘结性能.%It was the introducted of substituted phenols--cardanol with long chain alkyl group in the ortho phenol formaldehyde resin system, using strongly basic macroporous anion exchange resin as catalyst was modified, after the test and research, has been well prepared cashew phenol ortho phenyl phenol formaldehyde resin adhesive technology. Through the IR, DSC, TG and other means of cashew phenol ortho phenyl phenol formaldehyde resin structure, curing properties and heat resistance are analyzed, results show that, the synthetic resin structure contains cardanol, the resin heat resistance is better than that of ortho phenyl phenol formaldehyde resin, toughness and excellent bonding properties.

  2. Noble Metal Nanoparticle-loaded Mesoporous Oxide Microspheres for Catalysis

    Jin, Zhao

    Noble metal nanoparticles/nanocrystals have attracted much attention as catalysts due to their unique characteristics, including high surface areas and well-controlled facets, which are not often possessed by their bulk counterparts. To avoid the loss of their catalytic activities brought about by their size and shape changes during catalytic reactions, noble metal nanoparticles/nanocrystals are usually dispersed and supported finely on solid oxide supports to prevent agglomeration, nanoparticle growth, and therefore the decrease in the total surface area. Moreover, metal oxide supports can also play important roles in catalytic reactions through the synergistic interactions with loaded metal nanoparticles/nanocrystals. In this thesis, I use ultrasonic aerosol spray to produce hybrid microspheres that are composed of noble metal nanoparticles/nanocrystals embedded in mesoporous metal oxide matrices. The mesoporous metal oxide structure allows for the fast diffusion of reactants and products as well as confining and supporting noble metal nanoparticles. I will first describe my studies on noble metal-loaded mesoporous oxide microspheres as catalysts. Three types of noble metals (Au, Pt, Pd) and three types of metal oxide substrates (TiO2, ZrO2, Al 2O3) were selected, because they are widely used for practical catalytic applications involved in environmental cleaning, pollution control, petrochemical, and pharmaceutical syntheses. By considering every possible combination of the noble metals and oxide substrates, nine types of catalyst samples were produced. I characterized the structures of these catalysts, including their sizes, morphologies, crystallinity, and porosities, and their catalytic performances by using a representative reduction reaction from nitrobenzene to aminobenzene. Comparison of the catalytic results reveals the effects of the different noble metals, their incorporation amounts, and oxide substrates on the catalytic abilities. For this particular

  3. Simultaneous metal adsorption on tannin resins

    Vegetable tannin sorbent is evaluated as ion exchange resin using a multitracer study on the adsorption behavior of various elements. Lisiloma latisiliqua L. tannins, polycondensated into spherical pellets were chosen as sorbent resin material. Sorption evaluation of Ce, Cu(II), U(VI), Eu, Fe(III), Th, Nd as representatives of different classes of metal ions were done at different pH values. The distribution ratio of the studied elements was calculated from laboratory experiments. Tannic ion exchange material shows excellent ability for actinides and rare earth elements adsorption from waters. Using radiotracers, the number of catechins subunits involve in each tannin-metal complex was determined. (author)

  4. Color stability of recent composite resins

    Ardu, Stefano; Duc, Olivier; Di Bella, Enrico; Krejci, Ivo

    2016-01-01

    The objective of the study was to evaluate the color stability of 8 recently developed resin composites when exposed to various staining agents. Six disc-shaped specimens made out of 8 resin composite materials were immersed in artificial saliva, coffee, coke, tea, orange juice and red wine. The initial color (T0) of the 288 specimens was assessed by a calibrated reflectance spectrophotometer (SpectroShade, MHT) over a black as well as a white background. All specimens were kept in an incubat...

  5. Treatment of liquid wastes using composite resins

    Composite ion exchange resins were prepared by coating copper ferrocyanide and hydrous manganese oxide powders on polyurethane foam. The binder used was polyvinyl acetate in alcohol/acetone medium. Studies were conducted in pilot scale using 50 L ion exchange column and treated category III radioactive liquid wastes. About 2000 to 2400 bed volumes of liquid wastes containing radioactive 137Cs and 90Sr were treated. Digestion of the resins was carried out in a 25 L column using alkaline KMnO4. The digested liquid was fixed in cement matrix and the matrices were characterized with respect to compressive strength, biological and leach resistance. (author)

  6. PMR Resin Compositions For High Temperatures

    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.

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

    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.

  8. Interacting Blends of Novel Unsaturated Polyester Amide Resin with Styrene

    Hasmukh S. Patel; Panchal, Kumar K.

    2004-01-01

    Novel unsaturated poly (ester-amide) resins (UPEAs) were prepared by the reaction between an epoxy resin, namely diglycidyl ether of bisphenol–A (DGEBA) and unsaturated aliphatic bisamic acids using a base catalyst. These UPEAs were then blended with a vinyl monomer namely, Styrene (STY.) to produce a homogeneous resin syrup. The curing of these UPEAs-STY. resin blends was carried out by using benzoyl peroxide (BPO) as a catalyst and was monitored by using a differential scanning calorimeter ...

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

    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.

  10. Performances and improvement of copper-hydrazine complexation deoxidising resin

    Copper-hydrazine complexation deoxidising resin is tested to examine its performances including effluent water quality and capacity of deoxidisation. By the means of changing the resin type and regeneration, the deoxidising capacity of the resin can be improved to 13 times more than before. At the same time, physical performances of the resin are also greatly improved while maintaining its velocity of deoxidisation and effluent quality. (authors)

  11. Synthesis of highly carboxylate acrylic resins for leather impregnation

    Ollé Otero, Lluís; Solé, M.M.; Shendrik, Alexander; Labastida, L.; Bacardit Dalmases, Anna

    2012-01-01

    This work describes the synthesis of new leather finishing acrylic resins. Four resins ware synthesized varying the concentration of ethyl acrylate, and metracrylic acid. Sodium lauryl sulphate was used as emulsifying system. By means of an experimental design, an optimal resin for leather impregnation was defined. The results obtained indicated that the variation of the monomer concentration influences the resin properties, the hardness of the film, and the penetration into the leather. Most...

  12. Effect of Sandblasting on Shear Bond Strength Composite Resin Veneer

    Octarina Octarina; Andi Soufyan; Yosi Kusuma Eriwati

    2013-01-01

    Attachment between restoration and enamel surface in indirect resin composite veneer restoration (IRCV) is obtained using multi-step (MS) resin cement. Recently, a one step self-adhesive dual-cured resin cement (SADRC) was introduced. Objective: To determine the effect of sandblasting on shear bond strength (SBS) of IRCV to enamel using MS resin cement and SADRC. Methods: Forty specimens of buccal surface of enamel human were light-cured in Solidilite chamber and were divided into two groups...

  13. Multitasking mesoporous nanomaterials for biorefinery applications

    Kandel, Kapil

    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

  14. Multitasking mesoporous nanomaterials for biorefinery applications

    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. Preparation of mesoporous titania particles using ionic liquid dissolving starch as templates

    CHEN Chunming; RAN Jingwen; YE Qiunan

    2009-01-01

    A mesoporous titania photocatalyst was prepared via calcining the solution of ionic liquid (1-methyl-3-butyl imidazolium bromide,[BMIM]Br) containing tetrabutyl titanate (TBT) and starch. The microstructure of the prepared mesoporous titania was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N2 adsorption/desorption iso-therm. The results indicate that the resulting mesoporous titania has a grain size of about 13.9 nm, a special surface area of 106 m2/g, and a pore volume of 0.22 cm3/g, and the pore size can be adjusted by the concentration of starch in ionic liquid. The photocatalytic activity of mesoporous titania in the degradation of methyl orange solution was determined. The effect of the specific surface area of mesoporous titania on the photocatalytic activity was also studied. The prepared mesoporous titania exhibits a high catalytic activity.

  16. Curing reaction of bisphenol-A based benzoxazine with cyanate ester resin and the properties of the cured thermosetting resin

    H. Kimura

    2011-12-01

    Full Text Available Curing reaction of bisphenol-A based benzoxazine with cyanate ester resin and the properties of the cured thermosetting resin were investigated. The cure behavior of benzoxazine with cyanate ester resin was monitored by model reaction using nuclear magnetic resonance (NMR. As a result of the model reaction, the ring opening reaction of benzoxazine ring and thermal self-cyclotrimerization of cyanate ester group occurred, and then the phenolic hydoroxyl group generated by the ring opening reaction of benzoxazine ring co-reacted with cyanate ester group. The properties of the cured thermosetting resin were estimated by mechanical properties, electrical resistivity, water resistance and heat resistance. The cured thermosetting resin from benzoxazine and cyanate ester resin showed good heat resistance, high electrical resistivity and high water resistance, compared with the cured thermosetting resin from benzoxazine and epoxy resin.

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

    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. 21 CFR 173.10 - Modified polyacrylamide resin.

    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...

  19. 21 CFR 872.3820 - Root canal filling resin.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Root canal filling resin. 872.3820 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device composed of material, such as methylmethacrylate,...

  20. 40 CFR 721.5905 - Modified phenolic resin (generic).

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

    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...

  2. 40 CFR 721.5908 - Modified phenolic resin (generic).

    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...

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

    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.

  4. Electron sensitive resin and fabrication process of this one

    The invention concerns electron sensitive negative resins, that is to say the resins which, when subjected to the action of an electronic beam of adequate power, undergo a transformation that makes them resistant to certain chemical agents or insoluble in certain solvents. The invention also concerns a process for manufacturing this resin which is a 2.3 epithiopropylmethacrylate copolymer

  5. TRIMETHYLSILYLATED SILICA AS RHEOLOGY MODIFIER FOR SILICONE RESINS

    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.

  6. 21 CFR 872.3310 - Coating material for resin fillings.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Coating material for resin fillings. 872.3310... (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...

  7. 21 CFR 872.3300 - Hydrophilic resin coating for dentures.

    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...

  8. 21 CFR 177.2510 - Polyvinylidene fluoride resins.

    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...

  9. 40 CFR 721.4380 - Modified hydrocarbon resin.

    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)...

  10. Development of radiation-curable resin based on natural rubber

    A new radiation curable resin based on natural rubber has been developed. The resin was based on the reaction between low molecular weight epoxidised natural rubber and acrylic acid. When formulated with reactive monomers and photoinitiator, it solidified upon irradiation with UV light. The resin may find applications in coating for cellulosic-based substrates and pressure-sensitive adhesive

  11. 21 CFR 177.2420 - Polyester resins, cross-linked.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyester resins, cross-linked. 177.2420 Section... as Components of Articles Intended for Repeated Use § 177.2420 Polyester resins, cross-linked. Cross-linked polyester resins may be safely used as articles or components of articles intended for...

  12. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin... acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid with the...

  13. 40 CFR 721.9499 - Modified silicone resin.

    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)...

  14. 40 CFR 721.2673 - Aromatic epoxide resin (generic).

    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...

  15. Mesoporous yttria-zirconia and metal-yttria-zirconia solid solutions for fuel cells

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

    2000-02-03

    A new class of binary mesoporous yttria-zirconia (YZ) and ternary mesoporous metal-YZ materials (M = electroactive Ni/Pt) is presented here that displays the highest surface area of any known form of yttria-stabilized zirconia. These mesoporous materials form as solid solutions and retain their structural integrity to 800 C, which bodes well for their possible utilization in fuel cells. (orig.)

  16. Highly mesoporous metal–organic framework assembled in a switchable solvent

    PENG Li; Zhang, Jianling; Xue, Zhimin; Han, Buxing; Sang, Xinxin; Liu, Chengcheng; Yang, Guanying

    2014-01-01

    The mesoporous metal–organic frameworks are a family of materials that have pore sizes ranging from 2 to 50 nm, which have shown promising applications in catalysis, adsorption, chemical sensing and so on. The preparation of mesoporous metal–organic frameworks usually needs the supramolecular or cooperative template strategy. Here we report the template-free assembly of mesoporous metal–organic frameworks by using CO2-expanded liquids as switchable solvents. The mesocellular metal–organic fra...

  17. CuO nanoparticles encapsulated inside Al-MCM-41 mesoporous materials via direct synthetic route

    Chengli Huo; Jing Ouyang; Huaming Yang

    2014-01-01

    Highly ordered aluminum-containing mesoporous silica (Al-MCM-41) was prepared using attapulgite clay mineral as a Si and Al source. Mesoporous complexes embedded with CuO nanoparticles were subsequently prepared using various copper sources and different copper loadings in a direct synthetic route. The resulting CuO/Al-MCM-41 composite possessed p6mm hexagonally symmetry, well-developed mesoporosity, and relatively high BET surface area. In comparison to pure silica, these mesoporous material...

  18. Synthesis of novel Mesoporous Fullerene and its application to electro-oxidation of methanol

    Mondal, Sujit K.

    2010-01-01

    One pot synthetic technique was used to synthesize mesoporous fullerene using highly ordered mesoporous template such as KIT6-150 and SBA-15-150. Highly ordered porous fullerene with cross linkage between the fullerene molecules was obtained at high temperature 900 0C. This type of highly ordered and high surface area mesoporous fullerence was used as catalyst to study anodic performance in sulphuric acid medium. Finally, it was used to test its catalytic activity for electrochemical methanol...

  19. Effect of polysulfonate resins and direct compression fillers on multiple-unit sustained-release dextromethorphan resinate tablets

    Pongjanyakul, Thaned; Priprem, Aroonsri; Chitropas, Padungkwan; Puttipipatkhachorn, Satit

    2005-01-01

    The purpose of this work was to investigate the effect of different polysulfonate resins and direct compression fillers on physical properties of multiple-unit sustained-release dextromethorphan (DMP) tablets. DMP resinates were formed by a complexation of DMP and strong cation exchange resins, Dowex 50 W and Amberlite IRP69. The tablets consisted of the DMP resinates and direct compression fillers, such as microcrystalline cellulose (MCC), dicalcium phosphate dihydrate (DCP), and spray-dried...

  20. Effect of epoxy resin properties on the mechanical properties of carbon fiber/epoxy resin composites

    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.)

  1. Low-melt Viscosity Polyimide Resins for Resin Transfer Molding (RTM) II

    Chuang, Kathy C.; Criss, Jim M.; Mintz, Eric A.; Scheiman, Daniel A.; Nguyen, Baochau N.; McCorkle, Linda S.

    2007-01-01

    A series of polyimide resins with low-melt viscosities in the range of 10-30 poise and high glass transition temperatures (Tg s) of 330-370 C were developed for resin transfer molding (RTM) applications. These polyimide resins were formulated from 2,3,3 ,4 -biphenyltetracarboxylic dianhydride (a-BPDA) with 4-phenylethynylphthalic anhydride endcaps along with either 3,4 - oxyaniline (3,4 -ODA), 3,4 -methylenedianiline, (3,4 -MDA) or 3,3 -methylenedianiline (3,3 -MDA). These polyimides had pot lives of 30-60 minutes at 260-280 C, enabling the successful fabrication of T650-35 carbon fiber reinforced composites via RTM process. The viscosity profiles of the polyimide resins and the mechanical properties of the polyimide carbon fiber composites will be discussed.

  2. 21 CFR 177.2440 - Polyethersulfone resins.

    2010-04-01

    ...) resins (CAS Reg. No. 25667-42-9), which have a minimum number average molecular weight of 16,000. (2) 1,1... percent) (CAS Reg. No. 88285-91-0), which have a minimum number average molecular weight of 26,000. (3) In paragraphs (a)(1) and (a)(2) of this section, the minimum number average molecular weight is determined...

  3. Microbial treatment of ion exchange resins

    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)

  4. Microbial treatment of ion exchange resins

    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)

  5. [Resin-bonded fixed partial dentures

    Kreulen, C.M.; Creugers, N.H.J.

    2013-01-01

    A resin-bonded fixed partial denture is a prosthetic construction which can replace I or several teeth in an occlusal system and which comprises a pontic element which is adhesively attached to 1 or more abutment teeth. To compensate for the limited shear strength of the adhesive layer, the Jixed pa

  6. Process for preparing cured polyester resins

    A novel process for preparing cured unsaturated polyester resins is provided. The process comprises incorporating an unsaturated polyester resin with a vinyl monomer having an epoxy group, shaping the resulting mixture into a desired form (coatings, molded articles or impregnations), isolating it from the air by covering it with a polyester film (for example, a Mylar film) the surface of which has preliminarily been activated by suitable means such as corona discharge, flame treating plasma jet, gamma rays or chemical grafting agents, and then irradiating the unsaturated polyester with ionizing radiations. The process is advantageous in its simplicity of procedure and high weather and chemical resistance of the cured product. In one example, an unsaturated polyester resin was mixed with 0.1% by wt. of glycidyl methacrylate and coated a decorative laminate. Next, the coated surface was covered with a polyester film the surface of which had preliminarily been activated by means of corona discharge. The resin was irradiated with electron beams (500 keV, 10 Mrad) and then heated to 1000C for 30 min. Thus, a decorative board coated with a cured polyester layer in which the unsaturated polyester and the polyester film were unified was obtained. It was highly resistant to chloroform, acetone and alkali. (Kaichi, S.)

  7. Evaluation of resins for use in brachytherapy

    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)

  8. Introduction of bridging and pendant organic groups into mesoporous alumina materials.

    Grant, Stacy M; Woods, Stephan M; Gericke, Arne; Jaroniec, Mietek

    2011-11-01

    Incorporation of organic functionalities into soft-templated mesoporous alumina was performed via organosilane-assisted evaporation induced self-assembly using aluminum alkoxide precursors and block copolymer templates. This strategy permits one to obtain mesoporous alumina-based materials with tailorable adsorption, surface and structural properties. Isocyanurate, ethane, mercaptopropyl, and ureidopropyl-functionalized mesoporous alumina materials were synthesized with relatively high surface area and large pore volume with uniform and wormhole-like mesopores. The presence of organosilyl groups within these hybrid materials was confirmed by IR or Raman spectroscopy and their concentration was determined by elemental analysis. PMID:21988174

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

    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.

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

    Seong Huh

    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 Cu{sup 2+} 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 Cu{sup 2+} 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 system that is

  11. Morphological control of multifunctionalized mesoporous silica nanomaterials for catalysis applications

    Huh, Seong

    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 Cu 2+ 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 system that is capable of

  12. Using mesoporous carbon electrodes for brackish water desalination.

    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

  13. Bisphenol-A epoxy resin reinforced and toughened by hyperbranched epoxy resin

    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.

  14. EPICOR-II resin degradation results from first resin samples of PF-8 and PF-20

    The 28 March 1979 accident at Three Mile Island Unit 2 released approximately 560,000 gallons of contaminated water to the Auxiliary and Fuel Handling Buildings. The water was decontaminated using a demineralization system called EPICOR-II developed by Epicor, Inc. The Low-Level Waste Data Base Development-EPICOR-II Resin/Liner Investigation Project, founded by the US Nuclear Regulatory Commission, is studying the chemical and physical conditions of the synthetic ion exchange resins found in several EPICOR-II prefilters. The work is being done by EG and G Idaho, Inc. at the Idaho National Engineering Laboratory. This report summarizes results and analyses of the first sampling of ion exchange resins form EPICOR-II prefilters PF-8 and 20. Results are compared with baseline data from tests performed on unirradiated Epicor, Inc. resins to determine if degradation had occurred due to the high internal radiation dose received by the EPICOR-II resins. Results also are compared with resent findings on resin degradation by Battelle Columbus Laboratories and Brookhaven National Laboratory. 16 refs., 46 figs., 6 tabs

  15. Electrochemical regeneration of spent ion exchange resin

    CAN-DECON™, CAN-DEREM™ and CAN-DEREM Plus™ processes developed by Atomic Energy of Canada Limited (AECL) are dilute regenerative chemical decontamination processes that employ ion exchange resin to remove dissolved metals and radionuclides and to regenerate the reagents. Depending on the system volume and oxide and radionuclide inventories, a large volume of spent ion exchange resin may be generated. Storage and long term disposal of spent resin may be one of the impediments to routine use of chemical decontamination processes. An electrochemical method is being developed by AECL for the regeneration of spent ion exchange resin generated during application of CAN-DECON, CAN-DEREM and CAN-DEREM Plus processes. In addition, some of the work being carried out is directed at methods for liquid waste treatment. This paper will describe the three-compartment electrochemical cell developed for laboratory tests. The cell consists of an anode, cathode and central compartment, the latter containing either solid spent resin or spent solution. The anode and the cathode compartments are separated from the central section by cation exchange membranes which allow cations to transport from anode to cathode compartments through the membranes. The paper will discuss the results of cyclic voltammetry tests performed in CAN-DEREM reagents to determine the iron redox potential in these electrolytes. The results of iron deposition tests performed in simulated spent CAN-DEREM reagents to study the current efficiency of iron deposition as a function of iron concentration, pH, cathode material and temperature will be presented. The results of tests of several commercial cation exchange membranes to study transport efficiency of iron through these membranes will also be discussed. (author)

  16. Commercial Ion Exchange Resin Vitrification in Borosilicate Glass

    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

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

    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. PMID:25872710

  18. Synthesis and characterization of acidic mesoporous borosilicate thin films.

    Xiu, Tongping; Liu, Qian; Wang, Jiacheng

    2009-02-01

    Work on the synthesis and characterization of acidic wormhole-like ordered mesoporous borosilicate thin films (MBSTFs) on silicon wafers is described in this paper. The MBSTFs coated by the dip-coating method were prepared through an evaporation-induced self-assembly (EISA) process using nonionic block copolymers as structure-directing agents. Fourier transform infrared (FT-IR) spectroscopy confirmed the formation of borosiloxane bonds (Si-O-B). High-resolution transmission electron microscopy (HRTEM) and N2 sorption evidenced a wormhole-like mesoporous structure in the MBSTFs obtained. Scanning electron microscopy (SEM) images of the cross sections and surfaces of the samples showed that MBSTFs on silicon wafers were continuous, homogeneous and did not crack. The acidic properties of the MBSTFs were characterized by FT-IR spectra of chemisorbed pyridine. The MBSTFs thus prepared may find their future applications in many fields including chemical sensors, catalysis, optical coating, molecule separation, etc. PMID:19441565

  19. Designing advanced functional periodic mesoporous organosilicas for biomedical applications

    Dolores Esquivel

    2014-03-01

    Full Text Available Periodic mesoporous organosilicas (PMOs, reported for the first time in 1999, constitute a new branch of organic-inorganic hybrid materials with high-ordered structures, uniform pore size and homogenous distribution of organic bridges into a silica framework. Unlike conventional mesoporous silicas, these materials offer the possibility to adjust the surface (hydrophilicity/hydrophobicity and physical properties (morphology, porosity as well as their mechanical stability through the incorporation of different functional organic moieties in their pore walls. A broad variety of PMOs has been designed for their subsequent application in many fields. More recently, PMOs have attracted growing interest in emerging areas as biology and biomedicine. This review provides a comprehensive overview of the most recent breakthroughs achieved for PMOs in biological and biomedical applications.

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

    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.

  1. Fluorescent Functionalized Mesoporous Silica for Radioactive Material Extraction

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

    2012-08-01

    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.

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

    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.

  3. Natural dye -sensitized mesoporous ZnO solar cell

    Wu, Qishuang; Shen, Yue; Wu, Guizhi; Li, Linyu; Cao, Meng; Gu, Feng

    2011-02-01

    Natural dye-sensitized solar cells (N-DSSCs) were assembled using chlorophyll sensitized mesoporous ZnO (based on FTO) as the photoanode and platinum plate as the cathode. The natural dyes (chlorophyll) were extracted from spinach by simple procedure. The absorption spectrum and fluorescence spectrum of chlorophyll were studied. Mesoporous ZnO (m-ZnO) applied to the N-DSSCs was synthesized through hydrothermal method. The structures and morphologies were characterized by X-ray Diffraction (XRD) and diffuse reflection. The results indicated that the samples had an average pore size of 17 nm and the m-ZnO was hexagonal wurtzite structure. The performances of the N-DSSCs were investigated under AM 1.5G illumination. The Voc of the N-DSSCs was about 480mv, and the Isc was about 470μA. The performance of the N-DSSCs could be further improved by adjusting its structure.

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

    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.

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

    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.

  6. Liquid-phase synthesized mesoporous electrochemical supercapacitors of nickel hydroxide

    Chang, Jinho; Park, Mira; Ham, Dukho; Mane, Rajaram S.; Han, Sung-Hwan [Inorganic Nano-Materials Laboratory, Department of Chemistry, Hanyang University, Sungdong-Ku, Haengdang-dong 17, Seoul 133-791 (Korea); Ogale, S.B. [Physical and Materials Chemsitry Division, National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune 411008 (India)

    2008-06-01

    Electrochemical supercapacitive (ES) properties of liquid-phase synthesized mesoporous (pore size distribution centered {proportional_to}12 nm) and of 120 m{sup 2}/g surface area nickel hydroxide film electrodes onto tin-doped indium oxide substrate are discussed. The amounts of inner and outer charges are calculated to investigate the contribution of mesoporous structure on charge storage where relatively higher contribution of inner charge infers good ion diffusion into matrix of nickel hydroxide. Effect of different electrolytes, electrolyte concentrations, deposit mass and scan rates on the current-voltage profile in terms of the shape and enclosed area is investigated. Specific capacitance of {proportional_to}85 F/g at a constant current density of 0.03 A/g is obtained from the discharge curve. (author)

  7. Preparation of mesoporous silica films SBA-15 over different substrates

    Mesoporous materials have been target of frequent interest due to its wide application possibilities, for example development of gas sensors, catalysis, molecules transportation, pharmaceuticals release, synthesis of auto-organized nanostructures, among others. The possibilities of application are enhanced when such materials are disposed in the form of thin and ultrathin films. In this work the preparation of mesoporous SBA-15 silica films is explored by means of the dipcoating technique of a sol-gel on different substrates (glass slides, stainless steel, copper), using the surfactant poly(ethylene glycol)-block-poly(propylene glycol)- block-poly(ethylene glycol), known as P123, a block copolymer. Synthesis parameters surfactant concentration, aging time and temperature were investigated. In this work we present the morphological and structural characterization of the prepared films, which were obtained using atomic force microscopy and x-ray fluorescence and diffraction. (author)

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

    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.

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

    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.

  10. Template preparation of twisted nanoparticles of mesoporous silica

    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.

  11. Comparison of Mechanical Properties of Resin Composites with Resin Modified Glass Ionomers

    Taha NA

    2015-06-01

    Full Text Available Statement of Problem: There are controversial reports regarding physical and mechanical properties of resin composites and glass ionomer cements. Some revealed higher strength and hardness for resin composites while others showed a comparable value for glass ionomer cements. Evaluation of mechanical properties of different types of resin composites in comparison with resin modified glass ionomers is not widely studied. Objectives: To measure and compare the flexural strength and Vickers hardness of three resin composites and two resins modified glass ionomer cements before and after ageing. Materials and Methods: Three resin composites, i.e. Filtek Supreme XTE (3M ESPE, Ice (SDI, Gradia (GC, and two resins modified glass ionomers, i.e. Fuji II LC (GC and Riva Light Cure (SDI, were selected. Ten barshaped specimens were prepared for each material and cured using LED curing light. After 24 hours storage in distilled water at 37oC, the specimens were randomly divided into two equal groups (n=5. The first group was tested as a baseline and the second group was restored at 37oC for another 29 days. Flexural strength was performed by four-point bending test using universal testing machine at crosshead speed of 0.5mm/min, and the maximum load at failure was recorded. The specimen’s halves were used for evaluating Vickers hardness, using a Digital Hardness Tester (300 g/15 sec and the Vickers hardness number (VHN was recorded. Data were analyzed using one-way analysis of variance (ANOVA, Tukey’s and student’s t-test. Results: After 24 hours of immersion, the highest hardness number was found for Filtek Supreme and Ice and the highest flexural strength was obtained for Gradia. After 30 days of storage, hardness of Fuji II LC and Gradia showed a significant decrease; flexural strength of Ice and Fuji II LC revealed a significant increase while Gradia and Filtek Supreme showed a significant decrease. Conclusions: Resin modified glass ionomers showed

  12. Treatment of spent ion-exchange resins for disposal

    Ion-exchange resins are used in CANDU-PHW nuclear power stations to purify heavy water in the primary heat transport (PHT) and moderator systems. Two techniques for conditioning spent ion-exchange resins for disposal have been evaluated: direct immobilization, and incineration combined with immobilization of the ash and scrubbed off-gases. When ion-exchange resins were immobilized directly, no volume reductions were obtained at the various resin-to-matrix weight ratios attempted. Volumes of bitumen and glass products were equal to the volumes of untreated resin while the volumes of cement and polyester products were two and three times larger. While incinerating the resin is an extra processing step, high reductions in volume result. Bitumen and glass product volumes were six times smaller than the volumes of untreated resin while cement and polyster product volumes were about half the volume of untreated resin. Since the releases of Cs-137 were about ten times lower for products made by direct immobilization, PHT resins, which have high concentrations of Cs-137, should be immobilized directly. Moderator resins which have high concentrations of C-14 should be incinerated and the ash- and C-14-contaminated scrubbing solutions should be immobilized. By pretreating such resins with calcium chloride, the C-14 present on resin could be released at temperatures below the ignition temperature of the resin. This technique reduces the amount of inactive carbon dioxide that must be scrubbed to trap the C-14. The releases of C-14 from immobilized barium hydroxide scrubbing solution were the same as releases from immobilized resin

  13. Development and application of high performance resins for crud removal

    The development of crud removal technology has started with the finding of the resin aging effect that an old ion exchange resin, aged by long year of use in the condensate demineralizer, had an enhanced crud removal capability. It was confirmed that some physical properties such as specific surface area and water retention capacity were increased due to degradation caused by long year of contact with active oxygens in the condensate water. So, it was speculated that those degradation in the resin matrix enhanced the adsorption of crud particulate onto the resin surface, hence the crud removal capability. Based on this, crud removal resin with greater surface area was first developed. This resin has shown an excellent crud removal efficiency in an actual power plant, and the crud iron concentration in the condensate effluent was drastically reduced by this application. However, the cross-linkage of the cation resin had to be lowered in a delicate manner for that specific purpose, and this has caused higher organic leachables from the resin, and the sulfate level in the reactor was raised accordingly. Our major goals, therefore, has been to develop a crud resin of as little organic leachables as possible with keeping the original crud removal efficiency. It was revealed through the evaluation of the first generation crud resin and its improved version installed in the actual condensate demineralizers that there was a good correlation between crud removal efficiency and organic leaching rate. The bast one among a number of developmental resins has shown the organic leaching rate of 1/10 of that of the original crud resin (ETR-C), and the crud removal efficiency of 90%. So far as we understand, the resin was considered to have the best overall balance between crud removal and leaching characteristics. The result of six month evaluation of this developmental resin, ETR-C3, in one vessel of condensate demineralizer of a power plant will be presented. (J.P.N.)

  14. Uranium Adsorption on Ion-Exchange Resins - Batch Testing

    Mattigod, Shas V.; Golovich, Elizabeth C.; Wellman, Dawn M.; Cordova, Elsa A.; Smith, Ronald M.

    2010-12-01

    The uranium adsorption performance of five resins (Dowex 1, Dowex 21K 16-30 [fresh], Dowex 21K 16-30 [regenerated], Purofine PFA600/4740, and ResinTech SIR-1200) were tested using unspiked, nitrate-spiked, and nitrate-spiked/pH adjusted source water from well 299-W19-36. These batch tests were conducted in support of a resin selection process in which the best resin to use for uranium treatment in the 200-West Area groundwater pump-and-treat system will be identified. The results from these tests are as follows: • The data from the high-nitrate (1331 mg/L) tests indicated that Dowex 1, Dowex 21K 16-30 (fresh), Purofine PFA600/4740, and ResinTech SIR-1200 all adsorbed uranium similarly well with Kd values ranging from ~15,000 to 95,000 ml/g. All four resins would be considered suitable for use in the treatment system based on uranium adsorption characteristics. • Lowering the pH of the high nitrate test conditions from 8.2 to 7.5 did not significantly change the uranium adsorption isotherms for the four tested resins. The Kd values for these four resins under high nitrate (1338 mg/L), lower pH (7.5) ranged from ~15,000 to 80,000 ml/g. • Higher nitrate concentrations greatly reduced the uranium adsorption on all four resins. Tests conducted with unspiked (no amendments; nitrate at 337 mg/L and pH at 8.2) source water yielded Kd values for Dowex 1, Dowex 21K 16-30 (fresh), Purofine PFA600/4740, and ResinTech SIR-1200 resins ranging from ~800,000 to >3,000,000 ml/g. These values are about two orders of magnitude higher than the Kd values noted from tests conducted using amended source water. • Compared to the fresh resin, the regenerated Dowex 21K 16-30 resin exhibited significantly lower uranium-adsorption performance under all test conditions. The calculated Kd values for the regenerated resin were typically an order of magnitude lower than the values calculated for the fresh resin. • Additional testing using laboratory columns is recommended to better

  15. Carbon black directed synthesis of ultrahigh mesoporous carbon aerogels

    Macías, Carlos; Haro Remón, Marta; Rasines, Gloria; Parra Soto, José Bernardo; Ovín Ania, María Concepción

    2013-01-01

    [EN] A simple modification of the conventional sol–gel polymerization of resorcinol–formaldehyde mixtures allowed a facile preparation of ultrahigh mesoporous carbon gels. In the conventional synthesis the growth of the cluster polymer particles leading to the development of the porosity is controlled by the R/C ratio. In the presence of a carbon conductive additive, the polymerization of the reactants proceeded through the formation of less-branched polymer clusters resulting in carbon gels ...

  16. Oxidative nanopatterning of titanium generates mesoporous surfaces with antimicrobial properties

    Variola F; SF Zalzal; Leduc A; Barbeau J; Nanci A

    2014-01-01

    Fabio Variola,1,2 Sylvia Francis Zalzal,3 Annie Leduc,3 Jean Barbeau,3 Antonio Nanci31Faculty of Engineering, Department of Mechanical Engineering, 2Faculty of Science, Department of Physics, University of Ottawa, Ottawa, ON, 3Faculty of Dental Medicine, Université de Montréal, Montreal, QC, CanadaAbstract: Mesoporous surfaces generated by oxidative nanopatterning have the capacity to selectively regulate cell behavior, but their impact on microorganisms has not yet been explore...

  17. Oxidative nanopatterning of titanium generates mesoporous surfaces with antimicrobial properties

    Variola, Fabio

    2014-01-01

    Fabio Variola,1,2 Sylvia Francis Zalzal,3 Annie Leduc,3 Jean Barbeau,3 Antonio Nanci31Faculty of Engineering, Department of Mechanical Engineering, 2Faculty of Science, Department of Physics, University of Ottawa, Ottawa, ON, 3Faculty of Dental Medicine, Université de Montréal, Montreal, QC, CanadaAbstract: Mesoporous surfaces generated by oxidative nanopatterning have the capacity to selectively regulate cell behavior, but their impact on microorganisms has not yet been...

  18. A Reversible Light-Operated Nanovalve on Mesoporous Silica Nanoparticles

    Tarn, Derrick; Ferris, Daniel P.; Barnes, Jonathan C.; Ambrogio, Michael W.; Stoddart, J. Fraser; Zink, Jeffrey I.

    2014-01-01

    Two azobenzene α-cyclodextrin based nanovalves are designed, synthesized and assembled on mesoporous silica nanoparticles. When in aqueous conditions, the cyclodextrin cap is tightly bound to the azobenzene moiety and capable of holding back loaded cargo molecules. Upon irradiation with a near-UV light laser, trans to cis- photoisomerization of azobenzene initiates a dethreading process, which causes the cyclodextrin cap to unbind followed by the release of cargo. The addition of a bulky stop...

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

    Porous materials with various pore sizes in the range of micropore ( 50 nm) are attractive due to their many emerging applications such as catalysts, separation systems, and low dielectric constant materials. The discovery of new M41S mesoporous silica families with pore sizes larger than 2 nm in diameter in 1992 extended the applications into much wider pore ranges, bringing in a new prosperous era in porous material research. The synthesis of these silica materials has been mainly accomplished through a self-assembly between surfactant molecules and inorganic species under various pH conditions. Recently, core-shell nanoparticles with a silica core and mesoporous shell under basic conditions were synthesized using the silica nanoparticles as a core, and a silica precursor (TEOS) and cationic surfactant (CTABr) as a material for the formation of the mesoporous shell. The resultant materials were very monodispersive in size and showed a narrow pore size distribution in the range of ca 2-3 nm in diameter, depending on the alkyl-chain length of the surfactants used. In this work, the mesoporous shell coated-fumed silicas (denoted as MS M-5s) were synthesized by using fumed silica instead of the silica nanoparticle as a core based on previous reports. Also, the structural properties of the MS M-5s such as the specific surface area and pore volume were easily controlled by varying the amount of the silica precursor and surfactant. The resultant materials exhibited a BET surface area of ca 279-446 m2/g and total pore volume of ca 0.64-0.74 cm3/g and showed a narrow pore size distribution (PSD) due to the removal of the organic surfactant molecules

  20. Green Synthesis of Benzylated Aromatics Using Iron Loaded Mesoporous Materials

    Preethi, Muthuraj Esther Leena; Revathi, Shanmugam; Sivakumar, Thiripuranthagan

    2008-01-01

    Syntheses of benzylated aromatics like diphenylmethane and its derivatives by the condensation of benzene or toluene or o-xylene with benzylchloride or 4-methylbenzylchloride in the presence of a catalytic amount of various iron loaded mesoporous solid acid catalysts such as Fe/Al-MCM-41 (Si/Al=25), Fe/Al-MCM-41 (Si/Al=50) and Fe/Al-MCM-41 (Si/Al=100) are reported.

  1. Synthese und Charakterisierung aromatischer periodisch mesoporöser Organosilicas

    Morell, Jürgen

    2008-01-01

    Die zugrunde liegende Arbeit befasst sich mit der Synthese und Charakterisierung aromatischer periodisch mesoporöser Organosilicas. Neben der Untersuchung des Bildungsmechanismus Biphenyl-verbrückter PMO-Materialien durch in situ-SAXS-Messungen wurden eine Reihe Thiophen-verbrückter PMOs unter Verwendung verschiedener Tenside als Strukturdirektoren synthetisiert. Es konnten so 2D-hexagonale sowie kubische Produkte erhalten werden. Des Weiteren konnte die Synthese von bifunktionellen PMO-Mat...

  2. Biomolecule-assisted route to prepare titania mesoporous hollow structures.

    Ding, Shangjun; Wang, Yaoming; Hong, Zhanglian; Lü, Xujie; Wan, Dongyun; Huang, Fuqiang

    2011-10-01

    Amino acids, as a particularly important type of biomolecules, have been used as multifunctional templates to intelligently construct mesoporous TiO(2) hollow structures through a simple solvothermal reaction. The structure-directing behaviors of various amino acids were systematically investigated, and it was found that these biomolecules possess the general capability to assist mesoporous TiO(2) hollow-sphere formation. At the same time, the nanostructures of the obtained TiO(2) are highly dependent on the isoelectric points (pI) of amino acids. Their molecular-structure variations can lead to pI differences and significantly influence the final TiO(2) morphologies. Higher-pI amino acids (e.g., L-lysine and L-arginine) have better structure-directing abilities to generate nanosheet-assembled hollow spheres and yolk/shell structures. The specific morphologies and mesopore size of these novel hollow structures can also be tuned by adjusting the titanium precursor concentration. Heat treatment in air and vacuum was further conducted to transform the as-prepared structures to porous nanoparticle-assembled hollow TiO(2) and TiO(2)/carbon nanocomposites, which may be potentially applied in the fields of photocatalysts, dye-sensitized solar cells, and Li batteries. This study provides some enlightenment on the design of novel templates by taking advantage of biomolecules. PMID:21882272

  3. Mesoporous hydroxyapatite: Preparation, drug adsorption, and release properties

    Mesoporous hydroxyapatite (HA) was synthesized through gas–liquid chemical precipitation method at ambient temperature without any template. Structure, morphology and pore size distribution of HA were analyzed via X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution electron microscopy and N2 adsorption/desorption. The chemotherapeutic agent doxorubicin (DOX) was used to investigate the drug adsorption and release behavior of HA. The kinetics of DOX adsorption on HA followed the pseudo-second-order rate expression. Adsorption isotherms at various temperatures were obtained, and the equilibrium data fitted the Langmuir model. The values of thermodynamic parameters (Gibbs free energy, entropy, and enthalpy changes) demonstrated that the adsorption process was spontaneous and endothermic. In vitro pH-responsive (pH = 7.4, 5.8) controlled release was investigated. DOX-loaded HA showed a slow, long-term, and steady release rate. The release rate at pH5.8 was larger than that at pH7.4. Consequently, the as-prepared mesoporous HA has potential applications in controlled drug delivery systems. - Highlights: • Mesoporous HA was synthesized by a simple precipitation method without any template. • The kinetics of adsorption followed the pseudo-second-order rate expression. • Thermodynamics investigation showed that adsorption was spontaneous and endothermic. • DOX-loaded HA showed a long-term, steady, and pH-controlled release rate

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

    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.

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

    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.

  6. Sustained release of fungicide metalaxyl by mesoporous silica nanospheres

    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.

  7. Sustained release of fungicide metalaxyl by mesoporous silica nanospheres

    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

  8. Adsorption behavior of natural anthocyanin dye on mesoporous silica

    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.

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

    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.

  10. Selective Response of Mesoporous Silicon to Adsorbants with Nitro Groups

    McLeod, John A.; Kurmaev, Ernst Z.; Sushko, Petr V.; Boyko, Teak D.; Levitsky, Igor A.; Moewes, Alexander

    2012-01-30

    We demonstrate that the electronic structure of mesoporous silicon is affected by adsorption of nitrobased explosive molecules in a compound-selective manner. This selective response is demonstrated by probing the adsorption of two nitro-based molecular explosives (trinitrotoluene and cyclotrimethylenetrinitramine) and a nonexplosive nitro-based aromatic molecule (nitrotoluene) on mesoporous silicon using soft X-ray spectroscopy. The Si atoms strongly interact with adsorbed molecules to form Si-O and Si-N bonds, as evident from the large shifts in emission energy present in the Si L2,3 X-ray emission spectroscopy (XES) measurements. Furthermore, we find that the energy gap (band gap) of mesoporous silicon changes depending on the adsorbant, as estimated from the Si L2,3 XES and 2p X-ray absorption spectroscopy (XAS) measurements. Our ab initio molecular dynamics calculations of model compounds suggest that these changes are due to spontaneous breaking of the nitro groups upon contacting surface Si atoms. This compound-selective change in electronic structure may provide a powerful tool for the detection and identification of trace quantities of airborne explosive molecules.

  11. Facile synthesis of mesoporous aluminosilicates constructed with crystalline microporous frameworks

    A hierarchically micro-mesoporous structured ZSM-5 zeolite has been synthesized from assembly of aluminosilcate species with a tetra-quaternary ammonium type surfactant, in which the surfactant acts as two-level structure-directing templates for generating micropores and mesopores simultaneously. The synthesized samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, N2 adsorption–desorption isotherms, scanning electron microscopy, transmission electron microscopy, 27Al magic angle spinning nuclear magnetic resonance, X-ray photoelectron spectroscopy, Thermogravimetric analysis and Quantum chemical calculation. X-ray diffraction as well as nitrogen sorption analyses indicated the dual-porosity of samples, one is from intra-crystalline micropores, and the other is from mesopores. Quantum chemical calculation results showed that the inner ammonium groups of surfactant had more higher molecular degrees of freedom for the zeolite-structure-directing function. Moreover, on the basis of the same concept, this method could be extended to investigate other hierarchically structured zeolites.

  12. Facile synthesis of mesoporous aluminosilicates constructed with crystalline microporous frameworks

    Liu, Baoyu, E-mail: liubaoyu084@163.com; Ren, Yanqun; Duan, Qianqian; Chen, Fei; Xi, Hongxia, E-mail: cehxxi@scut.edu.cn; Qian, Yu

    2013-08-15

    A hierarchically micro-mesoporous structured ZSM-5 zeolite has been synthesized from assembly of aluminosilcate species with a tetra-quaternary ammonium type surfactant, in which the surfactant acts as two-level structure-directing templates for generating micropores and mesopores simultaneously. The synthesized samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, N{sub 2} adsorption–desorption isotherms, scanning electron microscopy, transmission electron microscopy, {sup 27}Al magic angle spinning nuclear magnetic resonance, X-ray photoelectron spectroscopy, Thermogravimetric analysis and Quantum chemical calculation. X-ray diffraction as well as nitrogen sorption analyses indicated the dual-porosity of samples, one is from intra-crystalline micropores, and the other is from mesopores. Quantum chemical calculation results showed that the inner ammonium groups of surfactant had more higher molecular degrees of freedom for the zeolite-structure-directing function. Moreover, on the basis of the same concept, this method could be extended to investigate other hierarchically structured zeolites.

  13. Functionalized mesoporous silica nanoparticles for oral delivery of budesonide

    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.

  14. Adsorption Of Water And Benzene Vapour In Mesoporous Materials

    Paulina Taba

    2008-11-01

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

  15. A Review: Fundamental Aspects of Silicate Mesoporous Materials

    Zeid A. ALOthman

    2012-12-01

    Full Text Available Silicate mesoporous materials have received widespread interest because of their potential applications as supports for catalysis, separation, selective adsorption, novel functional materials, and use as hosts to confine guest molecules, due to their extremely high surface areas combined with large and uniform pore sizes. Over time a constant demand has developed for larger pores with well-defined pore structures. Silicate materials, with well-defined pore sizes of about 2.0–10.0 nm, surpass the pore-size constraint (<2.0 nm of microporous zeolites. They also possess extremely high surface areas (>700 m2 g−1 and narrow pore size distributions. Instead of using small organic molecules as templating compounds, as in the case of zeolites, long chain surfactant molecules were employed as the structure-directing agent during the synthesis of these highly ordered materials. The structure, composition, and pore size of these materials can be tailored during synthesis by variation of the reactant stoichiometry, the nature of the surfactant molecule, the auxiliary chemicals, the reaction conditions, or by post-synthesis functionalization techniques. This review focuses mainly on a concise overview of silicate mesoporous materials together with their applications. Perusal of the review will enable researchers to obtain succinct information about microporous and mesoporous materials.

  16. Hollow periodic mesoporous organosilica nanospheres by a facile emulsion approach.

    Ma, Xiaobo; Zhang, Junjie; Dang, Meng; Wang, Jin; Tu, Zenzen; Yuwen, Lihui; Chen, Guotao; Su, Xiaodan; Teng, Zhaogang

    2016-08-01

    Periodic mesoporous organosilicas (PMOs) with homogeneously incorporated organic groups, highly ordered mesopores, and controllable morphology have attracted increasing attention. In this work, one-step emulsion approach for preparation of hollow periodic mesoporous organosilica (HPMO) nanospheres has been established. The method is intrinsically simple and does not require any sacrificial templates, corrosive and toxic etching agents. The obtained HPMO nanospheres have high surface area (∼950m(2)g(-1)), accessible ordered mesochannels (∼3.4nm), large pore volume (∼3.96cm(3)g(-1)), high condensation degree (77%), and diameter (∼560nm), hollow chamber size (∼400nm), and shell thickness (∼80nm). Furthermore, cytotoxicity show the cell viability is higher than 86% after incubating with the HPMO nanospheres at a concentration of up to 1200μgmL(-1) for 24h. The hemolysis of HPMO nanospheres is lower than 1.1% at concentrations ranging from 10 to 2000μgmL(-1). The lower hemolysis and cytotoxicity make the HPMO nanospheres great promise for future biomedical applications. PMID:27156086

  17. Functionalized mesoporous silica nanoparticles for oral delivery of budesonide

    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

  18. Study of carbon monoxide oxidation on mesoporous platinum.

    Esterle, Thomas F; Russell, Andrea E; Bartlett, Philip N

    2010-09-10

    H(1) mesoporous platinum surfaces formed by electrodeposition from lyotropic liquid crystalline templates have high electroactive surface areas (up to 60 m(2) g(-1)) provided by the concave surface within their narrow (≈2 nm diameter) pores. In this respect, they are fundamentally different from the flat surfaces of ordinary Pt electrodes or the convex surfaces of high-surface-area Pt nanoparticles. Cyclic voltammetry of H(1) mesoporous Pt films in acid solution is identical to that for polycrystalline Pt, suggesting that the surfaces of the pores are made up of low-index Pt faces. In contrast, CO stripping voltammetry on H(1) mesoporous Pt is significantly different from the corresponding voltammetry on polycrystalline Pt and shows a clear prewave for CO oxidation and the oxidation CO at lower overpotential. These differences in CO stripping are related to the presence of trough sites where the low-index Pt faces that make up the concave surface of the pore walls meet. PMID:20578119

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

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

    2014-01-01

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

  20. Carbon dioxide capture using polyethylenimine-loaded mesoporous carbons

    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.

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

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

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

    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 x 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 degrees C. No significant influence of pH on adsorption was observed at pH 3 to 9; however, adsorption capacity decreased dramatically from pH 9 to 13. PMID:21516989

  3. Post-irradiation hardness of resin-modified glass ionomer cements and a polyacid-modified composite resin

    This study examined the post-irradiation hardness of resin-modified glass ionomer cements and a polyacid-modified composite resin using a digital microhardness tester. Change in hardness of these materials over a period of 6 months was compared to that of conventional glass ionomer cements and a composite resin. With the exception of the composite resin, all materials showed a significant increase in hardness over 24 h after their initial set. Dual-cure resin-modified glass ionomer cements showed decreased hardness with increased storage time in saline at 37oC. Results suggest that the addition of resins to glass ionomer cements does not improve initial hardness and does not negate the acid-base reaction of conventional cements. Resin addition may, however, lead to increased water sorption and decreased hardness. (author)

  4. Synthesis and Application of a New Acrylic Ester Resin for Recycling SIPA from its Water Solution

    2005-01-01

    A new acrylic ester polymer YWB-7 resin was prepared and characterized. The properties of YWB-7 resin were compared with those of the commercial Amberlite XAD-7, Diaion HP2MG and hypercrosslinked macroporous polymer NDA-150 resins. Both surface area and micropore area of YWB-7 resin were bigger than those of XAD-7 resin and HP2MG resin. The YWB-7 resin was successfully employed to recycle 5-sodiosulfoisophthalic acids (SIPA) from its solutions with and without methanol.

  5. Effect of Resin Coating and Chlorhexidine on Microleakage of Two Resin Cements after Storage

    F. Shafie

    2010-03-01

    Full Text Available Objective: Evaluating the effect of resin coating and chlorhexidine on microleakage of two resin cements after water storage.Materials and Methods: Standardized class V cavities were prepared on facial and lingual surfaces of one hundred twenty intact human molars with gingival margins placed 1mm below the cemento-enamel junction. Indirect composite inlays were fabricated and thespecimens were randomly assigned into 6 groups. In Groups 1 to 4, inlays were cemented with Panavia F2.0 cement. G1: according to the manufacturer’s instruction. G2: with light cured resin on the ED primer. G3: chlorhexidine application before priming. G4: withchlorhexidine application before priming and light cured resin on primer. G5: inlays were cemented with Nexus 2 resin cement. G6: chlorhexidine application after etching. Each group was divided into two subgroups based on the 24-hour and 6-month water storagetime. After preparation for microleakage test, the teeth were sectioned and evaluated at both margins under a 20×stereomicroscope. Dye penetration was scored using 0-3 criteria.The data was analyzed using Kruskal-Wallis and complementary Dunn tests.Results: There was significantly less leakage in G2 and G4 than the Panavia F2.0 control group at gingival margins after 6 months (P<0.05. There was no significant differences in leakage between G1 and G3 at both margins after 24 hours and 6 months storage. After 6months, G6 revealed significantly less leakage than G5 at gingival margins (P=0.033. In general, gingival margins showed more leakage than occlusal margins.Conclusion: Additionally, resin coating in self-etch (Panavia F2.0 and chlorhexidine application in etch-rinse (Nexus resin cement reduced microleakage at gingival margins after storage.

  6. 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

    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.

  7. Adsorption of L-phenylalanine onto mesoporous silica

    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.

  8. Epoxy resins used to seal brachytherapy seed

    Prostate cancer treatment with brachytherapy is recommended for patients with cancer at an early stage. In this treatment, small radioactive seeds are implanted directly in the prostate gland. These seeds are composed at least of one radionuclide carrier and an X-ray marker enclosed within a metallic tube usually sealed by laser process. This process is expensive and, furthermore, it can provoke a partial volatilization of the radionuclide and change the isotropy in dose distribution around the seed. In this paper, we present a new sealing process using epoxy resin. Three kinds of resins were utilized and characterized by scanning electron microscopy (SEM), energy dispersive X ray (EDS) and by differential scanning calorimetry (DSC) after immersion in simulated body fluid (SBF) and in sodium iodine solution (NaI). The sealing process showed excellent potential to replace the sealing laser usually employed. (author)

  9. Integrating Porous Resins In Enzymatic Processes

    Al-Haque, Naweed

    enzymes to be harnessed. Porous resins as opposed to other auxiliary phases, for example organic solvents, are nonbioavailable, biocompatible and offer simpler operational handling (no foaming and emulsification). This strategy has been applied effectively to single substrate – single product systems...... screening procedure. The screening therefore becomes a multi-objective task that has to be solved simultaneously. Such an approach has been applied in the method formulated in this framework. To overcome these challenges, different process strategies are required to obtain high yields. A number of different...... challenges and proposed solutions are discussed in chapter one of this thesis and have also been published as a review. In recent years, integrating porous resins as an auxiliary phase in enzymatic processes, to non-selectively bind the substrate and product as a means to alleviate substrate and product...

  10. Ethynylated aromatics as high temperature matrix resins

    Hurwitz, F. I.

    1987-01-01

    Difunctional and trifunctional arylacetylenes were used as monomers to form thermoset matrix resin composites. Composites can be hot-pressed at 180 C to react 80 percent of the acetylene groups. Crosslinking is completed by postcuring at 350 C. The postcured resins are thermally stable to nominally 460 C in air. As a result of their high crosslink density, the matrix exhibits brittle failure when uniaxial composites are tested in tension. Failure of both uniaixial tensile and flexural specimens occurs in shear at the fiber-matrix interface. Tensile fracture stresses for 0-deg composites fabricated with 60 v/o Celion 6K graphite fiber were 827 MPa. The strain to failure was 0.5 percent. Composites fabricated with 8 harness satin Celion cloth (Fiberite 1133) and tested in tension also failed in shear at tensile stresses of 413 MPa.

  11. Handling sticky resin by stingless bees (Hymenoptera, Apidae

    Markus Gastauer

    2011-06-01

    Full Text Available For their nest defense, stingless bees (Meliponini collect plant resins which they stick on intruders like ants or cleptobiotic robber bees causing their immobilization. The aim of this article is to identify all parts of stingless bee workers contacting these sticky resins. Of special interest are those body parts with anti-adhesive properties to resin, where it can be removed without residues. For that, extensive behavioral observations during foraging flight, handling and application of the resin have been carried out. When handling the resin, all tarsi touch the resin while walking above it. For transportation from plants to the nest during foraging flight, the resin is packed to the corbicula via tarsi and basitarsi of front and middle legs. Once stuck to the resin or after the corbicula had been unloaded, the bee's legs have to be cleaned thoroughly. Only the tips of the mandibles, that form, cut and apply the sticky resin, seem to have at least temporarily resin-rejecting properties.

  12. Evaluation of the resin oxidation process using Fenton's reagent

    The ion exchange resin is considered radioactive waste after its final useful life in nuclear reactors. Usually, this type of waste is treated with the immobilization in cement Portland, in order to form a solid monolithic matrix, reducing the possibility of radionuclides release in to environment. Because of the characteristic of expansion and contraction of the resins in presence of water, its incorporation in the common Portland cement is limited in 10% in direct immobilization, causing high costs in the final product. A pre-treatment would be able to reduce the volume, degrading the resins and increasing the load capacity of this material. This paper is about a method of degradation of ion spent resins from the nuclear research reactor of Nuclear and Energy Research Institute (IPEN/CNEN-SP), Brazil, using the Fenton's reagent. The resin evaluated was a mixture of cationic and anionic resins. The reactions were conducted by varying the concentration of the catalyst (25 to 80 mM), with and without external heat. The time of reaction was two hours. The concentration of 50 mM of catalyst was the most effective in degrading approximately 99%. The resin degradation was confirmed by the presence of CaCO3 as a white precipitate resulting from the reaction between the Ca(OH)2 and the CO2 from the resin degradation. It was possible to degrade the resins without external heating. The calcium carbonates showed no correlation with the residual resin mass. (author)

  13. A facile route to synthesize endurable mesopore containing ZSM-5 catalyst for methanol to propylene reaction.

    Sun, Chao; Du, Junming; Liu, Jian; Yang, Yisu; Ren, Nan; Shen, Wei; Xu, Hualong; Tang, Yi

    2010-04-21

    A novel route is proposed for the preparation of mesopore containing zeolite ZSM-5 via in situ hydrothermal treatment of a solution containing alkali-dissolved SBA-15 containing carbonized surfactant P123 in the mesopores; it exhibited prominent stability enhancement for methanol to propylene reaction. PMID:20461876

  14. A reconstruction strategy to synthesize mesoporous SAPO molecular sieve single crystals with high MTO catalytic activity.

    Wang, Chan; Yang, Miao; Li, Mingrun; Xu, Shutao; Yang, Yue; Tian, Peng; Liu, Zhongmin

    2016-05-11

    Mesoporous SAPO-34 single crystals with tunable porosity and Si content have been fast synthesized within 4 hours by a reconstruction strategy, which show excellent hydrothermal stability and MTO catalytic activity. This new strategy is further proven to be applicable to prepare other mesoporous SAPO molecular sieve single crystals. PMID:27101359

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

    Kustova, Marina; Egeblad, Kresten; Christensen, Claus H.; Kustov, Arkadii; Christensen, Christina Hviid

    measurements. Additionally, the results of diffusion of n-hexadecane in conventional and mesoporous zeolites are presented. Isomerization and cracking of n-hexadecane was chosen as model test reaction for these materials. All results support that mesoporous zeolites are superior catalysts due to improved mass...

  16. Surfactant-free synthesis of mesoporous and hollow silica nanoparticles with an inorganic template.

    Baù, Luca; Bártová, Barbora; Arduini, Maria; Mancin, Fabrizio

    2009-12-28

    A surfactant-free synthesis of mesoporous and hollow silica nanoparticles is reported in which boron acts as the templating agent. Using such a simple and mild procedure as a treatment with water, the boron-rich phase is selectively removed, affording mesoporous pure silica nanoparticles with wormhole-like pores or, depending on the synthetic conditions, silica nanoshells. PMID:20024287

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

    Highlights: • NiO mesoporous nanowall arrays are prepared via hydrothermal method. • Mesoporous nanowall arrays are favorable for fast ion/electron transfer. • NiO mesoporous nanowall arrays show good supercapacitor performance. - Abstract: Mesoporous nanowall NiO arrays are prepared by a facile hydrothermal synthesis method with a following annealing process. The NiO nanowall shows continuous mesopores ranging from 5 to 10 nm and grows vertically on the substrate forming a porous net-like structure with macropores of 20–300 nm. A plausible mechanism is proposed for the growth of mesoporous nanowall NiO arrays. As cathode material of pseudocapacitors, the as-prepared mesoporous nanowall NiO arrays show good pseudocapacitive performances with a high capacitance of 600 F g−1 at 2 A g−1 and impressive high-rate capability with a specific capacitance of 338 F g−1 at 40 A g−1. In addition, the mesoporous nanowall NiO arrays possess good cycling stability. After 6000 cycles at 2 A g−1, a high capacitance of 660 F g−1 is attained, and no obvious degradation is observed. The good electrochemical performance is attributed to its highly porous morphology, which provides large reaction surface and short ion diffusion paths, leading to enhanced electrochemical properties

  18. Micromolding in inverted polymer opals (MIPO): synthesis of hexagonal mesoporous silica opals

    Yang Sanming; Coombs, N.; Ozin, G.A. [Toronto Univ., Ont. (Canada). Materials Chemistry Research Group

    2000-12-15

    Regular arrays of hexagonal mesoporous silica spheres are crucial for a number of applications, but until now control of the diameter, dispersity, and packing of the spheres has not proved possible. These authors report a new method-micromolding in inverted polymer opals-that allows the synthesis of such hexagonal mesoporous silica opals for the first time. (orig.)

  19. Synthesis of morphology-controllable mesoporous Co3O4 and CeO2

    Recently, extensive works have been devoted to the morphology control of mesoporous materials with respect to their use in various applications. In this paper, we used two kinds of mesoporous silica, SBA-15 rods and spheres as hard templates to synthesize morphology-controllable mesoporous metal oxides. By carefully controlling the loading of metal precursors in the mesopores of the hard template, mesoporous Co3O4 and CeO2 with different morphologies, such as micrometer-sized rod, hollow sphere, saucer-like sphere, and solid sphere were conveniently obtained. The structural properties of these materials were characterized by XRD, BET, SEM and TEM. In addition, it is found that the differences observed in the textural properties of the two mesoporous metal oxides nanocasted from the same template can be attributed to the properties of metal precursors and the interaction between metal oxide and SiO2. Thus-obtained mesoporous metal oxides with such special morphologies may have a potential application in the field of environmental catalytic oxidation. - Graphical Abstract: Mesoporous Co3O4 and CeO2 with different morphologies, such as micrometer-sized rod, hollow sphere, saucer-like sphere, and solid sphere were synthesized by nanocasting.

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

    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

  1. Facile preparation of mesoporous carbon-silica-coated graphene for the selective enrichment of endogenous peptides.

    Zhang, Quanqing; Zhang, Qinghe; Xiong, Zhichao; Wan, Hao; Chen, Xiaoting; Li, Hongmei; Zou, Hanfa

    2016-01-01

    A sandwich-like composite composed of ordered mesoporous carbon-silica shell-coated graphene (denoted as graphene@mSiO2-C) was prepared by an in-situ carbonation strategy. A mesoporous silica shell was synthesized by a sol-gel method, and cetyltrimethyl ammonium bromide inside the mesopores were in-situ carbonized as a carbon source to obtain a carbon-silica shell. The resulting mesoporous carbon-silica material with a sandwich structure possesses a high surface area (600 m(2) g(-1)), large pore volume (0.587 cm(3) g(-1)), highly ordered mesoporous pore (3 nm), and high carbon content (30%). This material shows not only high hydrophobicity of graphene and mesoporous carbon but also a hydrophilic silica framework that ensures excellent dispersibility in aqueous solution. The material can capture many more peptides from bovine serum albumin tryptic digests than mesoporous silica shell-coated graphene, demonstrating great enrichment efficiency for peptides. Furthermore, the prepared composite was applied to the enrichment of low-abundance endogenous peptides in human serum. Based on Matrix-Assisted Laser Desorption/ Ionization Time of Flight Mass Spectrometry identification, the graphene@mSiO2-C could efficiently size-exclude proteins and enriches the low-abundant peptides on the graphene and mesoporous carbon. And based on the LC-MS/MS results, 892 endogenous peptides were obtained by graphene@mSiO2-C, hinting at its great potential in peptides analysis. PMID:26695263

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

    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.

  3. Hydroisomerization of hexane over micro-mesoporous zeolites with tailored structure and distribution of active sites

    Kaucký, Dalibor; Janošcová, J.; Tabor, Edyta; Rathouský, Jiří; Klein, P.; Sazama, Petr

    Caen : ENSICAEN, Université de Caen, 2015. s. 89-89. [International Symposium Advances Micro- and Mesoporous Materials /6./. 06.09.2015-09.09.2015, Sunset - Black Sea] R&D Projects: GA ČR GA15-12113S Institutional support: RVO:61388955 Keywords : micro- and mesoporous zeolite s * hydroisomerization * zeolite catalysts Subject RIV: CF - Physical ; Theoretical Chemistry

  4. Sequestration Resins for Accelerating Removal of Radioactive Contaminants

    The Electric Power Research Institute (EPRI) is developing sequestration resins that can be used in the treatment of nuclear plant water streams for the enhanced removal of ionic cobalt. EPRI is focusing on three key areas of success: 1. Plant safety. The resins that are synthesized must be fully tested to determine that no leachable species or decomposition products (in the event of a resin bed failure) would be introduced to the plant. 2. Acceptable system performance. The resins are currently being synthesized in a powdered form for use in the reactor water clean-up and fuel pool clean-up systems that utilize pre-coatable filter elements. The resins must have effective flocking behavior; uniform application over the underlay resin and efficient removal from the septa elements after use. Bead type resins are also under development. 3. Enhanced cobalt removal. The resins are expected to out-perform the currently used ion exchange resins in the removal of ionic cobalt. During nuclear plant maintenance or refueling outages, current ion exchange resins may require several days to reduce concentrations of cobalt (for example, radio-cobalt 60Co and 58Co) and other activated corrosion products to safe levels in reactor coolant streams. This performance limitation often delays key maintenance activities. EPRI's resins are expected to provide at least a three-fold increase in removal capacity in light water reactor coolants. These resins also offer the potential for higher overall removal efficiencies reducing occupational exposures and waste management costs. This paper addresses issues from the range of novel resin development for radio-cobalt removal from synthesis at the bench-top level through scale-up to demonstration of use in an actual operating nuclear power plant. (authors)

  5. Curing kinetics of alkyd/melamine resin mixtures

    Jovičić Mirjana C.

    2009-01-01

    Full Text Available Alkyd resins are the most popular and useful synthetic resins applied as the binder in protective coatings. Frequently they are not used alone but are modified with other synthetic resins in the manufacture of the coatings. An alkyd/melamine resin mixture is the usual composition for the preparation of coating called 'baking enamel' and it is cured through functional groups of resins at high temperatures. In this paper, curing kinetics of alkyd resins based on castor oil and dehydrated castor oil with melamine resin, has been studied by DSC method with programmed heating and in isothermal mode. The results determined from dynamic DSC curves were mathematically transformed using the Ozawa isoconversional method for obtaining the isothermal data. These results, degree of curing versus time, are in good agreement with those determined by the isothermal DSC experiments. By applying the Ozawa method it is possible to calculate the isothermal kinetic parameters for the alkyd/melamine resin mixtures curing using only calorimetric data obtained by dynamic DSC runs. Depending on the alkyd resin type and ratio in mixtures the values of activation energies of curing process of resin mixtures are from 51.3 to 114 kJ mol-1. The rate constant of curing increases with increasing the content of melamine resin in the mixture and with curing temperature. The reaction order varies from 1.12 to 1.37 for alkyd based on dehydrated castor oil/melamine resin mixtures and from 1.74 to 2.03 for mixtures with alkyd based on castor oil. Based on the results obtained, we propose that dehydrated castor oil alkyd/melamine resin mixtures can be used in practice (curing temperatures from 120 to 160°C.

  6. Cellulose whisker/epoxy resin nanocomposites

    Tang, Liming; Weder, Christoph

    2010-01-01

    New nanocomposites composed of cellulose nanofibers or “whiskers” and an epoxy resin were prepared. Cellulose whiskers with aspect ratios of ∼10 and ∼84 were isolated from cotton and sea animals called tunicates, respectively. Suspensions of these whiskers in dimethylformamide were combined with an oligomeric difunctional diglycidyl ether of bisphenol A with an epoxide equivalent weight of 185−192 and a diethyl toluenediamine-based curing agent. Thin films were produced by casting these mixtu...

  7. Fully bio-based epoxy resins

    Ertl, Johanna

    2015-01-01

    Epoxy resins are mainly produced by reacting bisphenol A with epichlorohydrin. Growing concerns about the negative health effects of bisphenol A are urging researchers to find alternatives. In this work diphenolic acid is suggested, as it derives from levulinic acid, obtained from renewable resources. Nevertheless, it is also synthesized from phenol, from fossil resources, which, in the current paper has been substituted by plant-based phenols. Two interesting derivatives were identified: dip...

  8. Solidification method for spent ion exchange resin

    A hydrophilic binder having a binder effect increased upon contact with water and a cellulose type fibrous binder for reinforcement are added each in an appropriate amount to spent ion exchange resins in a state moistened with water. After the water content of the mixture is appropriately adjusted, they are pelletized by press molding or extrusion molding. With such procedures, less swelling product are obtained which can be solidified into stable products. (T.M.)

  9. Synteser og studier av propargylterminerte resiner

    Rokvam, Karoline

    2014-01-01

    Formålet med dette prosjektet var utvikling av syntesemetoder for propargylterminerte resiner, en gruppe av høytemperaturbestandige herdeplastmaterialer som har interesse innen forsvars- og romfartssektoren. 4,4´-Bifenolmonopropargyleter ble syntetisert og forsøkt brukt som byggekloss i syntesen av silisiumholdige propargylterminerte monomerer. Inkorporering av silisium hadde til formål å redusere sprøheten til disse resintypene, noe som er et utbredt problem. Disse ble forsøkt syntetisert ve...

  10. Synthesis of Resins with Chiral Salen Complexes

    2001-01-01

    @@ The enormous growth in the use of polymer resin supports in solid phase combinatorial synthesis, and related methodologies, has re-stimulated interest in the area of polymer-supported transition metal complex catalyst .The recently developed chiral salen-based for the enantioselective ring opening of meso epoxides and kinetic resolution of terminal epoxides are appealing candidates for immobilization on solid support. The catalysts are reading prepare from inexpensive components, and are amenable to modification for attachment to a solid support.

  11. Curing of natural rubber and epoxy adhesive

    Low molecular weight epoxy resin based on diglycidyl ether of bisphenol A was synthesized and mixed at constant percentages with natural rubber. The rubber epoxy system was cured with various types of curing agents such as ethylene diamine, maleic anhydride as well as the prepared resole phenol formaldehyde. A study of the photo-induced crosslinking of the prepared elastic adhesives and film samples was carried out by exposure to ultraviolet lamp (300 w) for 2 weeks at 20 deg. C. Samples containing ethylene diamine were cured at 25 + - 1 deg. C. for 24 h while samples containing maleic anhydride or resole phenol formaldehyde resins were thermally cured at 150-170 deg. C. for 10 min. Cured adhesive compositions were tested mechanically and physically and evaluated as wood adhesives. While hardness, chemical resistance as well as heat stability of the prepared cured film sample were investigated. The obtained data indicate that the highest epoxy resin content and the presence of resole phenol formaldehyde resin in composition improve the tensile strength and adhesion properties on wood. While their cured film sample have the best hardness properties, chemical resistance and heat stability. (author)

  12. Surface integrity of provisional resin materials

    Abouelatta, O. B.; El-Bediwi, A.; Sakrana, A.; Jiang, X. Q.; Blunt, L.

    2006-03-01

    Provisional resin materials are widely used in prosthetic dentistry and play an important role in the success of restorative treatment. Therefore, these materials must meet the requirements of preserving surface integrity during the treatment process. This study was done to evaluate surface roughness and microhardness of two provisional resin materials after 37 °C water storage. Two rectangular samples 21 mm × 11 mm × 3 mm, one bis-acrylic (bis-acrylic-Protemp II) and one polyethyl methacrylate (Trim®-PEMA) were fabricated as examples of provisional materials (n = 5 per material). The specimens were stored in 37 °C deionized distilled water for 24 h, 1, 2 and 3 weeks. The control specimens were not stored in water. The surface roughness of the tested materials (n = 10) was measured using a profilometer. Microhardness tests were conducted using a Vickers microscope mounted indenter system (n = 10). At 24 h, the surface roughness was recorded with bis-acrylic-Protemp II as higher than methacrylate materials. No significant differences of microhardness between Trim®-PEMA and bis-acrylic-Protemp II were recognized at 1, 2 and 3 weeks. The microhardness values increased with the increase of surface roughness and vice versa in both Trim®-PEMA and bis-acrylic-Protemp II. Both surface roughness and microhardness are affected by water storage. Bis-acrylic-Protemp II revealed better results in hardness than methacrylate resins, whereas Trim®-PEMA has a better surface roughness.

  13. Composite fabrication via resin transfer molding technology

    Jamison, G.M.; Domeier, L.A.

    1996-04-01

    The IMPReS (Integrated Modeling and Processing of Resin-based Structures) Program was funded in FY95 to consolidate, evaluate and enhance Sandia`s capabilities in the design and fabrication of composite structures. A key driver of this and related programs was the need for more agile product development processes and for model based design and fabrication tools across all of Sandia`s material technologies. A team of polymer, composite and modeling personnel was assembled to benchmark Sandia`s existing expertise in this area relative to industrial and academic programs and to initiate the tasks required to meet Sandia`s future needs. RTM (Resin Transfer Molding) was selected as the focus composite fabrication technology due to its versatility and growing use in industry. Modeling efforts focused on the prediction of composite mechanical properties and failure/damage mechanisms and also on the uncured resin flow processes typical of RTM. Appropriate molds and test composites were fabricated and model validation studies begun. This report summarizes and archives the modeling and fabrication studies carried out under IMPReS and evaluates the status of composite technology within Sandia. It should provide a complete and convenient baseline for future composite technology efforts within Sandia.

  14. Thermal stability of ion-exchange resins

    The action of heat, radiation and oxidants on carbonchain polymers, such as ion-exchange resins, often cause irreversible chemical changes in macro molecules. These changes can be e g the rupture of the carbon-carbon single or double bond, and/or the degradation of the macro molecule. Ion-exchange materials also contain the far less stable bonds between functional groups and the polymer matrix. For this reason the thermal stability of ion-exchange mat- erials is mainly based on the behaviour of the functional groups, which are responsible for the ion-exchange. The solidification of the ion-exchange resin waste usually involves elevated tempera- tures. Bituminization is carried out at 130-160 degrees C. Cementa- tion is carried out at room temperature. However, cementation can generate temperatures of up to 100-120 degrees C in the solidifica- tion product during the curing period. In this study the swelling/ shrinking properties of different ion-exchange materials have been studied in air and water as a function of the drying time and temp- erature. The air dried resins were used as the reference material. The effect of sodium sulphate as a possible additive to reduce swelling was studied, The experiments which were performed and re- sults observed are discussed in detail in the Appendices. (Authors)

  15. Method of processing spent ion exchange resins

    Purpose: To decrease the amount of radioactive spent ion exchange resins generated from nuclear power plants, etc and process them into stable inorganic compounds through heat decomposition. Method: Spent ion exchange resins are heat-decomposed in an inert atmosphere to selectively decompose only ion exchange groups in the preceeding step while high molecular skeltons are completely heat-decomposed in an oxidizing atmosphere in the succeeding step. In this way, gaseous sulfur oxides and nitrogen oxides are generated in the preceeding step, while gaseous carbon dioxide and hydrogen requiring no discharge gas procession are generated in the succeeding step. Accordingly, the amount of discharged gases requiring procession can significantly be reduced, as well as the residues can be converted into stable inorganic compounds. Further, if transition metals are ionically adsorbed as the catalyst to the ion exchange resins, the ion exchange groups are decomposed at 130 - 300 0C, while the high molecular skeltons are thermally decomposed at 240 - 300 0C. Thus, the temperature for the heat decomposition can be lowered to prevent the degradation of the reactor materials. (Kawakami, Y.)

  16. Adsorption of Iminodiacetic Acid Resin for Lutetium

    熊春华; 姚彩萍; 王惠君

    2004-01-01

    The adsorption behavior and mechanism of a novel chelate resin,iminodiacetic acid resin(IDAAR) for Lu(Ⅲ) were investigated.The statically saturated adsorption capacity is 210.8 mg·g-1 at 298 K in HAc-NaAc medium.The Lu(Ⅲ) adsorbed on IDAAR can be eluted by 0.5 mol·L-1 HCl and the elution percentage reaches 96.5%.The resin can be regenerated and reused without obvious decrease in adsorption capacity.The apparent adsorption rate constant is k298=2.0×10-5 s-1.The adsorption behavior of IDAAR for Lu(Ⅲ) obeys the Freundlich isotherm.The thermodynamic adsorption parameters,enthalpy change ΔH,free energy change ΔG and entropy change ΔS of IDAAR for Lu(Ⅲ) are 13.1 kJ·mol-1,-1.37 kJ·mol-1 and 48.4 J·mol-1·K-1,respectively.The apparent activation energy is Ea=31.3 kJ·mol-1.The molar coordination ratio of the functional group of IDAAR to Lu(Ⅲ) is about 3∶1.The adsorption mechanism of IDAAR for Lu(Ⅲ) was examined by chemical method and IR spectrometry.

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

    Christensen, Christina Hviid; Johannsen, Kim; Toernqvist, Eric; Schmidt, Iver; Topsoe, Henrik; Christensen, Claus H.

    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......-butane from packed beds of conventional and mesoporous zeolite catalysts. Moreover, we discuss in detail the recent observation of improved activity and selectivity in the alkylation of benzene with ethene using mesoporous zeolite single crystal catalysts. For this reaction, we show by calculation of the...

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

    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.

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

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

    2014-12-16

    Compositions and methods of making are provided for treated mesoporous metal oxide microspheres electrodes. The 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, and wherein the composition has an electrical conductivity of at least 1.times.10.sup.-7 S/cm at 25.degree. C. and 60 MPa. The methods of making comprise forming a mesoporous metal oxide microsphere composition and treating the mesoporous metal oxide microspheres by at least one method selected from the group consisting of: (i) annealing in a reducing atmosphere, (ii) doping with an aliovalent element, and (iii) coating with a coating composition.

  20. Preparation of TiO2 nanotubes/mesoporous calcium silicate composites with controllable drug release.

    Xie, Chunling; Li, Ping; Liu, Yan; Luo, Fei; Xiao, Xiufeng

    2016-10-01

    Nanotube structures such as TiO2 nanotube (TNT) arrays produced by self-ordering electrochemical anodization have been extensively explored for drug delivery applications. In this study, we presented a new implantable drug delivery system that combined mesoporous calcium silicate coating with nanotube structures to achieve a controllable drug release of water soluble and antiphlogistic drug loxoprofen sodium. The results showed that the TiO2 nanotubes/mesoporous calcium silicate composites were successfully fabricated by a simple template method and the deposition of mesoporous calcium silicate increased with the soaking time. Moreover, the rate of deposition of biological mesoporous calcium silicate on amorphous TNTs was better than that on anatase TNTs. Further, zinc-incorporated mesoporous calcium silicate coating, produced by adding a certain concentration of zinc nitrate into the soaking system, displayed improved chemical stability. A significant improvement in the drug release characteristics with reduced burst release and sustained release was demonstrated. PMID:27287140

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

    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.

  2. Highly efficient dye-sensitized solar cells of thick mesoporous titania films derived from supramolecular templating

    Thick titania films of highly ordered orthorhombic pore organization and sufficient thickness up to a few micrometers have been synthesized via a supramolecular templated route and layer-by-layer deposition. An appropriate pre-heat treatment was applied to improve the mesopore accessibility. The mesoporous films were highly crystallized with the crystallite size of ∼12 nm regardless of the film thickness, due to the spatial confinement of mesopores. A high optical transparency was demonstrated for the mesoporous films, which is ascribed to the high mesoporosity and uniformity of the ordered film structure. Both the mesopore accessibility and optical transparency have contributed to the high performance of these films as photoanodes in the dye-sensitized solar cells, showing a maximum solar energy conversion efficiency of 6.02% for a film of 5.08 μm in thickness.

  3. Characterization Of Cycled Spherical Resorcinol-Formaldehyde Ion Exchange Resin

    This report presents characterization data for two spherical resorcinol-formaldehyde (sRF) resin beds that had processed cesium in non-radioactive and radioactive cycles. All column cycle operations for the resin beds including loading, displacements, elution, regeneration, breakthroughs, and solution analyses are reported in Nash and Duignan, 2009a. That report covered four ion exchange (IX) campaigns using the two ∼11 mL beds in columns in a lead-lag arrangement. The first two campaigns used Savannah River Site (SRS) Tank 2F nonradioactive simulant while the latter two were fed with actual dissolved salt in the Savannah River National Laboratory (SRNL) Shielded Cells. Both radioactive cycles ran to cesium breakthrough of the lead column. The resin beds saw in excess of 400 bed volumes of feed in each cycle. Resin disposal plans in tank farm processing depend on characterizations of resin used with actual tank feed. Following a final 30 bed volume (BV) elution with nitric acid, the resin beds were found to contain detectable chromium, barium, boron, aluminum, iron, sodium, sulfur, plutonium, cesium, and mercury. Resin affinity for plutonium is important in criticality safety considerations. Cesium-137 was found to be less than 10E+7 dpm/g of resin, similar to past work with sRF resin. Sulfur levels are reasonably consistent with other work and are expected to represent sulfur chemistry used in the resin manufacture. There were low but detectable levels of technetium, americium, and curium. Toxicity Characteristic Leaching Procedure (TCLP) work on the used (eluted) resin samples showed significant contents of mercury, barium, and chromium. One resin sample exceeded the TCLP level for mercury while the other metals were below TCLP levels. TCLP organics measurements indicated measurable benzene in one case, though the source was unknown. Results of this work were compared with other work on similar sRF resin characterizations in this report. This is the first work

  4. Effects of layering technique on the shade of resin overlays and the microhardness of dual cure resin cement

    Hoon-Sang Chang

    2014-06-01

    Full Text Available The purpose of this study was to assess the color of layered resin overlays and to test the early microhardness of dual cure resin cement (DCRC light cured through the layered resin overlays. Resin overlays of 1.5 mm thickness were fabricated with the A3 shade of Z350 (Group 1L, the A3B and A3E shades of Supreme XT (Group 2L, and the A3, E3, and T1 shades of Sinfony (Group 3L using one, two, and three layers, respectively (n = 7. Each layer of the resin overlays was set in equal thickness. The color of the resin overlays was measured with a colorimeter and compared with an A3 shade resin denture tooth. DCRC was light cured through the resin overlays, and the early microhardness of the DCRC was measured. The ΔE value between the denture tooth and the resin overlays and the Vickers hardness number (VHN of the DCRC were analyzed with one-way ANOVA and Tukey’s HSD test. The color differences were 8.9 ± 0.5, 5.3 ± 1.0, and 7.3 ± 0.5 and the VHNs were 19.4 ± 1.1, 21.1 ± 0.9, and 29.3 ± 0.6 for Groups 1L, 2L, and 3L, respectively. Therefore, to match the designated tooth color of resin inlays and to increase the early microhardness of DCRC, layered resin inlays are more appropriate than single-dentin-layer resin inlays. However, the translucent layer should be used cautiously because the color difference of resin inlays with a translucent layer was affected more than those without a translucent layer.

  5. Progress of the Application of Mesoporous Silica-Supported Heteropolyacids in Heterogeneous Catalysis and Preparation of Nanostructured Metal Oxides

    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.

  6. Modification of unsaturated polyester resins (UP) and reinforced UP resins via plasma treatment

    Li Guanglu; Wei Xing [State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 21009 (China); Wang Wanjun [State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 21009 (China); Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201203 (China); He Tao, E-mail: taohe@njut.edu.cn [State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 21009 (China); Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201203 (China); Li Xuemei, E-mail: xueemei.li@gmail.com [State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 21009 (China)

    2010-10-15

    Unsaturated polyester resins (UP) and reinforced composite unsaturated polyester resins (RCP) were made superhydrophobic by plasma assisted methods. Both CF{sub 4}-plasma-enhanced chemical vapor deposition (CF{sub 4}-PECVD) and alternative method were tested. The surfaces were characterized by water contact angle (CA) measurements and scanning electron microscopy (SEM). Water contact angle results indicated that CF{sub 4}-PECVD can significantly improve the wettability of UP surfaces, but suffer from difficulties for RCP surfaces. Alternatively, O{sub 2} plasma followed by self-assembly of octadecyltrichlorosilane (OTS) self-assembled monolayer (SAM) was tested. It was shown that regardless of the filler percentage, O{sub 2} plasma followed by self-assembly of OTS monolayer formation all led to superhydrophobic surfaces. The results provided a means to improve the wettability of reinforced UP resins (RCP).

  7. Modification of unsaturated polyester resins (UP) and reinforced UP resins via plasma treatment

    Li, Guanglu; Wei, Xing; Wang, Wanjun; He, Tao; Li, Xuemei

    2010-10-01

    Unsaturated polyester resins (UP) and reinforced composite unsaturated polyester resins (RCP) were made superhydrophobic by plasma assisted methods. Both CF 4-plasma-enhanced chemical vapor deposition (CF 4-PECVD) and alternative method were tested. The surfaces were characterized by water contact angle (CA) measurements and scanning electron microscopy (SEM). Water contact angle results indicated that CF 4-PECVD can significantly improve the wettability of UP surfaces, but suffer from difficulties for RCP surfaces. Alternatively, O 2 plasma followed by self-assembly of octadecyltrichlorosilane (OTS) self-assembled monolayer (SAM) was tested. It was shown that regardless of the filler percentage, O 2 plasma followed by self-assembly of OTS monolayer formation all led to superhydrophobic surfaces. The results provided a means to improve the wettability of reinforced UP resins (RCP).

  8. Modification of unsaturated polyester resins (UP) and reinforced UP resins via plasma treatment

    Unsaturated polyester resins (UP) and reinforced composite unsaturated polyester resins (RCP) were made superhydrophobic by plasma assisted methods. Both CF4-plasma-enhanced chemical vapor deposition (CF4-PECVD) and alternative method were tested. The surfaces were characterized by water contact angle (CA) measurements and scanning electron microscopy (SEM). Water contact angle results indicated that CF4-PECVD can significantly improve the wettability of UP surfaces, but suffer from difficulties for RCP surfaces. Alternatively, O2 plasma followed by self-assembly of octadecyltrichlorosilane (OTS) self-assembled monolayer (SAM) was tested. It was shown that regardless of the filler percentage, O2 plasma followed by self-assembly of OTS monolayer formation all led to superhydrophobic surfaces. The results provided a means to improve the wettability of reinforced UP resins (RCP).

  9. Uptake of actinides by sulphonated phosphinic acid resin from acid medium

    The removal of uranium and americium from nitric acid solutions by sulphonated phosphinic acid resin has been investigated. The capacity of the sulphonated resin exceeds the capacities of phosphinic acid resin and commercial cation exchange resin. Other advantages of the sulphonated resin for uranium and americium removal include reduced sensitivity to acidity and inert salt concentration. (author)

  10. Aromatization of alkanes over Pt promoted conventional and mesoporous gallosilicates of MEL zeolite

    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.

  11. Rapid dewatering of Powdex resins at a BWR

    For most BWR's a large portion of their radioactive waste produced is water demineralization resins, both powdered and bead. In order to minimize the quantities of resins produced, proper demineralizer operation, volume reduction and minimization techniques are relevant to spent resin dewatering and packaging. To meet burial requirements spent resin needs to be dewatered and packaged properly. Methods of dewatering spent resins have included centrifuge separation and pulling water out of the resin with a diaphragm pump. Various vendors are offering systems that provide rapid dewatering and volume reduction using filter/liners in combination with vacuum pumps and air blowers. The various systems required a standardized test program for proper comparison and evaluation. The program is described in this paper

  12. Epoxy resin developments for large superconducting magnets impregnation

    Rey, J. M.; Gallet, B.; Kircher, F.; Lottin, J. C.

    The future detectors ATLAS and CMS of the Large Hadron Collider at CERN will use two huge superconducting magnets. Both are now under design, and their electrical insulation could be realized using epoxy resin and a wet impregnation technique. Because of their large dimensions, and the indirect cooling of the superconductor, the strengths of the resin and of the resin/conductor interface are of major importance. A new generation of epoxy resins for vacuum/pressure impregnation methods has been tested, and compared with some classical and well-known epoxy resins used in impregnation techniques. In order to understand the mechanical behaviour at 4 K, the complete evolution from liquid state to low temperature service condition is considered. The paper will present some results on the mechanical properties, the density and the chemical shrinkage occurring during the polymerization and the thermal contraction between room temperature and 4 K for these different types of epoxy resins.

  13. Design of systems for handling radioactive ion exchange resin beads

    The flow of slurries in pipes is a complex phenomenon. There are little slurry data available on which to base the design of systems for radioactive ion exchange resin beads and, as a result, the designs vary markedly in operating plants. With several plants on-line, the opportunity now exists to evaluate the designs of systems handling high activity spent resin beads. Results of testing at Robbins and Meyers Pump Division to quantify the behavior of resin bead slurries are presented. These tests evaluated the following slurry parameters; resin slurry velocity, pressure drop, bead degradation, and slurry concentration effects. A discussion of the general characteristics of resin bead slurries is presented along with a correlation to enable the designer to establish the proper flowrate for a given slurry composition and flow regime as a function of line size. Guidelines to follow in designing a resin handling system are presented

  14. Use of dried ion exchange resin for heavy water system

    In order to prevent degradation of D2O in HANARO reflector system due to the moisture in the ion exchange resin, a method using the dried resin is developed. The physical change of dried resin was observed and measured. The performance was tested, and verified. The moisture content in the resin could be reduced to below 1% from its original content of about 55%. The integrated degradation of D2O for 20 years is estimated as 0.23% if the dried resin is used whenever it is replaced. This is much simpler process than the deuteration method which has been used in the other facilities such as heavy water reactors, and the cost of which is almost negligible. Should the dried resin be used for an existing deuteration facility, the generation of degraded D2O will be significantly reduced

  15. Do resin cements influence the cuspal deflection of teeth restored with composite resin inlays?

    da Rosa, Helen C V; Marcondes, Maurem L; de Souza, Niélli C; Weber, João B B; Spohr, Ana M

    2015-04-01

    The aim of this study was to evaluate the influence of different resin cements on the cuspal deflection of endodontically treated teeth restored with composite resin inlays. Sixty upper premolars were randomly divided into five groups (n=12): 1 - sound teeth; 2 - cavity; 3 - Rely X ARC; 4 - RelyX Unicem; 5 - SeT. The teeth from groups 2, 3, 4 and 5 received a MOD preparation and endodontic treatment. Impressions were made with vinyl polysiloxane and poured using type IV die stone in groups 3, 4 and 5. Inlays with composite resin were built over each cast and luted with the resin cements. A 200 N load was applied on the occlusal surface, and cuspal deflection was measured using a micrometer. After 24 h, cuspal deflection was measured again using a 300 N load. The Student t-test showed that there was no statistically significant difference between the 200 N and 300 N occlusal loads only for the sound teeth group (p = 0.389) and the RelyX ARC group (p = 0.188). ANOVA and Tukey'test showed that the sound teeth had the lowest mean cuspal deflection, differing statistically from the other groups (p<0.05). The highest cuspal deflections were obtained in the SeT group and the cavity group, with no statistical difference between them. Intermediate values were obtained in RelyX ARC group and RelyX Unicem group, which differed statistically. The self-adhesive resin cements RelyX Unicem and SeT showed less capacity to maintain the stiffness of the tooth/restoration complex than the conventional resin cement RelyX ARC. PMID:25950160

  16. Effects of Carbonization Temperature and Component Ratio on Electromagnetic Interference Shielding Effectiveness of Woodceramics

    Yubo Tao

    2016-07-01

    Full Text Available Woodceramics were fabricated in a vacuum through carbonization of wood powder impregnated with phenol formaldehyde (PF resin. The effects of carbonization temperature and mass ratio of wood/resin on electromagnetic interference (EMI shielding effectiveness (SE and morphology of woodceramics were explored. The PF resin made wood cell walls have the characteristics of glassy carbon. Wood axial tracheid and ray cells were filled with more glassy carbon by increasing addition of PF resin. Moreover, the increase of carbonization temperature was beneficial to improving SE. Woodceramics (mass ratio 1:1 obtained at 1000 °C presented a medium SE level between 30 MHz and 1.5 GHz.

  17. Multi‐component Epoxy Resin Formulation for High Temperature Applications

    Poynton, Gary

    2014-01-01

    The high functionality epoxy resins tetraglycidyl-4,4’-diaminodiphenyl-methane(TGDDM) and triglycidyl-p-aminophenol (TGPAP) are the main components in mostaerospace grade epoxy resin formulations. Owing to their high reactivity and highviscosity, TGDDM and TGPAP pose difficulties when used in wet layup compositemanufacturing. As such, these resins are often modified to achieve the desiredperformance both in the liquid and cured states.The main objective of this thesis is to optimise a low vis...

  18. SYNTHESIS OF A NEW SILICONE-CONTAINING BISMALEIMIDE COPOLYMER RESIN

    KUANG Wenfeng; CAI Xingxian; JIANG Luxia

    1997-01-01

    A copolymer of bismaleimide-diallylbisphenol A-diphenylsilandiol was synthesized and the copolymerization was studied by using N-phenylmaleimide, bisphenol A and diphenylsilandiol as model compounds. The copolymer could be well cured around 200 ℃, and the cured resins had good thermal stability. In the range of 170-210 ℃, a higher curing temperature was favorable to obtain more thermal stable resin by reducing the content of diphenylsilandiol cyclo-homopolymer in resin which would spoil its thermal stability.

  19. Internal stabilization of polycarbonate resins by two stage radiation process

    Gupta, Amitava (Inventor); Liang, Ranty H. (Inventor); Yavrouian, Andre H. (Inventor)

    1988-01-01

    A new polycarbonate copolymer resin is formed by internal generation of stabilizers bound to the polymer chain. Irradiation of a solid piece or a deoxygenated solution of the resin at a first frequency below 300 nm generates 2 to 8 mol percent of phenyl salicylate groups which are rearranged to dihydroxybenzophenone groups by irradiating the resin under oxygen excluding conditions at a second frequency from 300 to 320 nm.

  20. Mini fiberglass post for composite resin restorations: A clinical report.

    Morgan, Luís Fernando Dos Santos Alves; Martins, Adriana Vieira; Albuquerque, Rodrigo de Castro; Silveira, Rodrigo Richard; Silva, Nelson Renato França Alves; Moreira, Allysson Nogueira

    2016-06-01

    Threaded metal pins have been used to create additional retention for large composite resin restorations. However, their dark appearance may compromise esthetic outcome. The use of small fiberglass posts has been advocated as an alternative. This clinical report describes a mini fiberglass post (MFP) used to provide additional retention in a fractured anterior tooth that received a composite resin restoration. The MFP represents a promising option for creating additional retention for large composite resin restorations. PMID:26724848