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Sample records for preparing oxide gel

  1. Formulation and method for preparing gels comprising hydrous aluminum oxide

    Science.gov (United States)

    Collins, Jack L.

    2014-06-17

    Formulations useful for preparing hydrous aluminum oxide gels contain a metal salt including aluminum, an organic base, and a complexing agent. Methods for preparing gels containing hydrous aluminum oxide include heating a formulation to a temperature sufficient to induce gel formation, where the formulation contains a metal salt including aluminum, an organic base, and a complexing agent.

  2. Sol-gel preparation of uranium oxide spheres

    International Nuclear Information System (INIS)

    Dolezal, J.; Urbanek, V.

    1978-01-01

    Information is presented on problems of preparing nuclear fuel by the sol-gel method. Basic data on different process types are given. A more detailed description of the method of preparation of spherical particles of uranium oxide gel developed and used at the Nuclear Research Institute at Rez is given. Advantages and disadvantages of sol-gel materials are discussed in comparison with fuel materials prepared by classical precipitation methods. The feasibility of the sol-gel methods for preparing other materials is shortly mentioned and their application outlined. (author)

  3. Preparation of oxide glasses from metal alkoxides by sol-gel method

    Science.gov (United States)

    Kamiya, K.; Yoko, T.; Sakka, S.

    1987-01-01

    An investigation is carried out on the types of siloxane polymers produced in the course of the hydrolysis of silicon tetraethoxide, as well as the preparation of oxide glasses from metal alkoxides by the sol-gel method.

  4. Partial Oxidation of n-Butane over a Sol-Gel Prepared Vanadium Phosphorous Oxide

    Directory of Open Access Journals (Sweden)

    Juan M. Salazar

    2013-01-01

    Full Text Available Vanadium phosphorous oxide (VPO is traditionally manufactured from solid vanadium oxides by synthesizing VOHPO4∙0.5H2O (the precursor followed by in situ activation to produce (VO2P2O7 (the active phase. This paper discusses an alternative synthesis method based on sol-gel techniques. Vanadium (V triisopropoxide oxide was reacted with ortho-phosphoric acid in an aprotic solvent. The products were dried at high pressure in an autoclave with a controlled excess of solvent. This procedure produced a gel of VOPO4 with interlayer entrapped molecules. The surface area of the obtained materials was between 50 and 120 m2/g. Alcohol produced by the alkoxide hydrolysis reduced the vanadium during the drying step, thus VOPO4 was converted to the precursor. This procedure yielded non-agglomerated platelets, which were dehydrated and evaluated in a butane-air mixture. Catalysts were significantly more selective than the traditionally prepared materials with similar intrinsic activity. It is suggested that the small crystallite size obtained increased their selectivity towards maleic anhydride.

  5. Nanosized Ni-Mn Oxides Prepared by the Citrate Gel Process and Performances for Electrochemical Capacitors

    Institute of Scientific and Technical Information of China (English)

    Jianxin ZHOU; Xiangqian SHEN; Maoxiang JING

    2006-01-01

    Nanosized Ni-Mn oxide powders have been successfully prepared by thermal decomposition of the Ni-Mn citrate gel precursors. The powder materials derived from calcination of the gel precursors with various molar ratios of nickel and manganese at different temperatures and time were characterized using thermal analysis (TG-DSC), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Brunauer-Emmet-Teller (BET).The optimized processing conditions of calcination at 400℃ for 1 h with Ni/Mn molar ratio 6 were proved to produce the nanosized Ni-Mn oxide powders with a high specific surface area of 109.62 m2/g and nanometer particle sizes of 15~30 nm. The capacitance characteristics of the nanosized Ni-Mn oxide electrode in various concentrations of KOH solutions were studied by the cyclic voltammetry (CV) and exhibited both a doublelayer capacitance and a Faradaic capacitance which could be attributed to the electrode consisting of Ni-Mn oxides and residual carbons from the organic gel thermal decomposition. A specific capacitance of 194.8 F/g was obtained for the electrode at the sweep rate of 10 mV/s in 4 mol/L KOH electrolyte and the capacitor showed quite high cyclic stability and is promising for advanced electrochemical capacitors.

  6. Sol-gel prepared active ternary oxide coating on titanium in cathodic protection

    Directory of Open Access Journals (Sweden)

    VLADIMIR V. PANIC

    2007-12-01

    Full Text Available The characteristics of a ternary oxide coating, on titanium, which consisted of TiO2, RuO2 and IrO2 in the molar ratio 0.6:0.3:0.1, calculated on the metal atom, were investigated for potential application for cathodic protection in a seawater environment. The oxide coatings on titanium were prepared by the sol gel procedure from a mixture of inorganic oxide sols, which were obtained by forced hydrolysis of metal chlorides. The morphology of the coating was examined by scanning electron microscopy. The electrochemical properties of activated titanium anodes were investigated by cyclic voltammetry and polarization measurements in a H2SO4- and NaCl-containing electrolyte, as well as in seawater sampled on the Adriatic coast in Tivat, Montenegro. The anode stability during operation in seawater was investigated by the galvanostatic accelerated corrosion stability test. The morphology and electrochemical characteristics of the ternary coating are compared to that of a sol-gel-prepared binary Ti0.6Ru0.4O2 coating. The activity of the ternary coating was similar to that of the binary Ti0.6Ru0.4O2 coating in the investigated solutions. However, the corrosion stability in seawater is found to be considerably greater for the ternary coating.

  7. RBS and NRA of cobalt oxide thin films prepared by the sol-gel process

    International Nuclear Information System (INIS)

    Andrade, E.; Huerta, L.; Pineda, J.C.; Zavala, E.P.; Barrera, E.; Rocha, M. F.; Vargas, C.A.

    2001-01-01

    This work presents a study of cobalt oxide thin films produced by the sol-gel process on aluminum and glass substrates. These films have been analyzed using two ion beam analysis (IBA) techniques: a) a standard RBS 4 He 2 MeV and b) nuclear reaction analysis (NRA) using a 1 MeV deuterium beam. The 12 C(d,p 0 ) 13 C nuclear reaction provides information that carbon is incorporated into the film structure, which could be associated to the sinterization film process. Other film measurements such as optical properties, XRD, and SEM were performed in order to complement the IBA analysis. The results show that cobalt oxide film coatings prepared by this technique have good optical properties as solar absorbers and potential uses in solar energy applications

  8. Hybrid manganese oxide films for supercapacitor application prepared by sol-gel technique

    International Nuclear Information System (INIS)

    Chen, Chin-Yi; Wang, Sheng-Chang; Tien, Yue-Han; Tsai, Wen-Ta; Lin, Chung-Kwei

    2009-01-01

    Hybrid films were prepared by adding various concentrations of meso-carbon microbeads (MCMB) during sol-gel processing of manganese oxide films. The heat-treated films were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). In addition, electrochemical performance of the MCMB-added Mn-oxide hybrid coatings was evaluated by cyclic voltammetry (CV) and compared with its unadded counterpart. Experimental results showed that Mn-oxide films exhibited a mixture of Mn 2 O 3 and Mn 3 O 4 phases. The higher the heat-treatment temperature, the more Mn 2 O 3 can be observed. The specific capacitance of the unadded Mn-oxide electrodes is 209 F/g. Because the MCMB particles provide more interfacial surface area for electrochemical reactions, a significant improvement can be noticed by adding MCMB in Mn-oxide coatings. The 300 o C heat-treated hybrid Mn-oxide coating with a Mn/MCMB ratio of 10/1 exhibits the highest value of 350 F/g, showing a ∼ 170% increase in specific capacitance.

  9. Comparison of the redox activities of sol-gel and conventionally prepared Bi-Mo-Ti mixed oxides

    Energy Technology Data Exchange (ETDEWEB)

    Wildberger, M.; Grundwaldt, J.D.; Mallat, T.; Baiker, A. [Lab. of Technical Chemistry, Swiss Federal Inst. of Technology, ETH-Zentrum, Zuerich (Switzerland)

    1998-12-31

    Novel sol-gel Bi-Mo-Ti oxides have been prepared and characterized by XRD, XPS, FT-Raman and HRTEM. The surface Bi{sup 3+} and Mo{sup 6+} species of some xerogels and an aerogel could be reduced and oxidized at room temperature, whereas the conventionally prepared reference materials were not reduced by H{sub 2} below 300 C. The unusual redox properties, under very mild conditions, are likely due to the unique morphology of Bi-Mo-oxides stabilized by titania. During butadiene oxidation to furan at above 400 C to sol-gel mixed oxides restructured considerably and their performance was barely better than that of titania-supported Bi-Mo oxides. (orig.)

  10. Alcohol sensing of tin oxide thin film prepared by sol–gel process

    Indian Academy of Sciences (India)

    Unknown

    variation of sensitivity and ethanol concentration has shown a linear relationship up to 1150 ppm and after ... The results obtained favour the sol–gel process as a low cost method for the preparation ... It was cleaned ultrasonically in methanol.

  11. The chemical and catalytic properties of nanocrystalline metal oxides prepared through modified sol-gel synthesis

    Science.gov (United States)

    Carnes, Corrie Leigh

    The goal of this research was to synthesize, characterize and study the chemical properties of nanocrystalline metal oxides. Nanocrystalline (NC) ZnO, CuO, NiO, Al2O3, and the binary Al2O 3/MgO and ZnO/CuO were prepared through modified sol gel methods. These NC metal oxides were studied in comparison to the commercial (CM) metal oxides. The samples were characterized by XRD, TGA, FTIR, BET, and TEM. The NC samples were all accompanied by a significant increase in surface area and decrease in crystallite size. Several chemical reactions were studied to compare the NC samples to the CM samples. One of the reactions involved a high temperature reaction between carbon tetrachloride and the oxide to form carbon dioxide and the corresponding metal chloride. A similar high temperature reaction was conducted between the metal oxide and hydrogen sulfide to form water and the corresponding metal sulfide. A room temperature gas phase adsorption was studied where SO2 was adsorbed onto the oxide. A liquid phase adsorption conducted at room temperature was the destructive adsorption of paraoxon (a toxic insecticide). In all reactions the NC samples exhibited greater activity, destroying or adsorbing a larger amount of the toxins compared to the CM samples. To better study surface area effects catalytic reactions were also studied. The catalysis of methanol was studied over the nanocrystalline ZnO, CuO, NiO, and ZnO/CuO samples in comparison to their commercial counterparts. In most cases the NC samples proved to be more active catalysts, having higher percent conversions and turnover numbers. A second catalytic reaction was also studied, this reaction was investigated to look at the support effects. The catalysis of cyclopropane to propane was studied over Pt and Co catalysts. These catalysts were supported onto NC and CM alumina by impregnation. By observing differences in the catalytic behavior, support effects have become apparent.

  12. Fabrication and Optical Characterization of Zinc Oxide Nanoparticles Prepared via a Simple Sol-gel Method

    Directory of Open Access Journals (Sweden)

    K. Hedayati

    2015-10-01

    Full Text Available In this research zinc oxide (ZnO nano-crystalline powders were prepared by sol-gel method using zinc acetate. The ZnO nanoparticles were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, ultraviolet-visible (UV-Vis, Fourier transform infra-red (FT-IR and energy dispersive X-ray (EDX spectroscopy. The structure of nanoparticles was studied using XRD pattern. The crystallite size of ZnO nanoparticles was calculated by Debye–Scherrer formula. Morphology of nano-crystals was observed and investigated using the SEM. The grain size of zinc oxide nanoparticles were in suitable agreement with the crystalline size calculated by XRD results. The optical properties of particles were studied with UV-Vis an FTIR absorption spectrum. The Raman spectrum measurements were carried out using a micro-laser Raman spectrometer forms the ZnO nanoparticles. At the end studied the effect of calcined temperature on the photoluminescence (PL emission of ZnO nanoparticles.

  13. Zinc oxide films impurified with Ti and prepared by the Sol-gel method

    International Nuclear Information System (INIS)

    Tirado G, S.; Cazares R, J.M.; Maldonado, A.

    2006-01-01

    Titanium-doped zinc oxide thin films have been prepared on silicon substrate using the Sol-Gel technique. The structural, morphology, electrical and optical properties of such thin films were studied as a function of titanium concentration (0.5, 1 and 1.5 %) and the thin films thickness. Zinc acetate dihydrate and titanium (VI)-oxy acetylacetonate were used as precursor materials, using 2-methoxyethanol and monoethanolamine as via. The X-ray diffraction spectra show polycrystalline films in all the cases. It can see for all the thin films a preferential growth along the (002) planes where the titanium concentration and also the thin films thickness play an important rule. No structural changes are observed at all. The surface morphology studied shows as the grain size decreases when thin thickness is increases. For titanium concentration of 0.5, 1 and 1.5 % values the grains size increase also. The thin films thickness for titanium concentration of 1.5 % was 500 nm (4v), 400 nm (3v), 180 nm (2v) and 130 nm (1v), values obtained from cross-section micrographs. Highly resistive samples are obtained for substrate soda-lime even showing high transmittance. Better physical properties are required for gas sensors or semitransparent electrodes and other possible applications. (Author)

  14. Preparation and properties of poly(ethylene oxide) gel filled polypropylene separators and their corresponding gel polymer electrolytes for Li-ion batteries

    International Nuclear Information System (INIS)

    Li Hao; Ma Xiaoting; Shi Junli; Yao Zhikan; Zhu Baoku; Zhu Liping

    2011-01-01

    Poly(ethylene oxide) (PEO) filled polypropylene separators (GFPSs) are designed by means of thermal cross-linking of entrapped poly(ethylene glycol) methyl ether acrylate (PEGMEA) and poly(ethylene glycol) diacrylate (PEGDA) as gel constituents. The intrinsic properties of GFPS and their corresponding gel polymer electrolytes (GPE) are characterized by DSC, SEM, contact angle and electrochemical methods. It is found the stability of liquid electrolyte uptake in GPE could be improved obviously. For the GPE prepared from GFPS with filled polyether content of 14.3 wt%, the ionic conductivity could reach 1.12 x 10 -3 S cm -1 while the electrochemically stable window reach 5.0 V (vs. Li/Li + ). These primary results show great promise of this simple method to prepare GPE for practical application in lithium ion batteries.

  15. Preparation and properties of poly(ethylene oxide) gel filled polypropylene separators and their corresponding gel polymer electrolytes for Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Li Hao; Ma Xiaoting; Shi Junli; Yao Zhikan [Department of Polymer Science and Engineering, Engineering Center of Membrane and Water Treatment, Key Laboratory of Macromolecule Synthesis and Functionalization (EMC), Zhejiang University, Hangzhou 310027 (China); Zhu Baoku, E-mail: zhubk@zju.edu.c [Department of Polymer Science and Engineering, Engineering Center of Membrane and Water Treatment, Key Laboratory of Macromolecule Synthesis and Functionalization (EMC), Zhejiang University, Hangzhou 310027 (China); Zhu Liping [Department of Polymer Science and Engineering, Engineering Center of Membrane and Water Treatment, Key Laboratory of Macromolecule Synthesis and Functionalization (EMC), Zhejiang University, Hangzhou 310027 (China)

    2011-02-15

    Poly(ethylene oxide) (PEO) filled polypropylene separators (GFPSs) are designed by means of thermal cross-linking of entrapped poly(ethylene glycol) methyl ether acrylate (PEGMEA) and poly(ethylene glycol) diacrylate (PEGDA) as gel constituents. The intrinsic properties of GFPS and their corresponding gel polymer electrolytes (GPE) are characterized by DSC, SEM, contact angle and electrochemical methods. It is found the stability of liquid electrolyte uptake in GPE could be improved obviously. For the GPE prepared from GFPS with filled polyether content of 14.3 wt%, the ionic conductivity could reach 1.12 x 10{sup -3} S cm{sup -1} while the electrochemically stable window reach 5.0 V (vs. Li/Li{sup +}). These primary results show great promise of this simple method to prepare GPE for practical application in lithium ion batteries.

  16. Comparison of sol-gel prepared catalysts for CO oxidation and N2O decomposition reactions.

    OpenAIRE

    Euesden, Claire

    2002-01-01

    This thesis comprises analysis for two types of catalysis: CO oxidation and N2O decomposition; related by their research in sol-gel catalysis. The CO oxidation work was undertaken on behalf of Servomex plc in order to understand how their catalyst-based sensor (Tfx 1750) worked and why it failed when exposed to coal power station flue streams within its two-year guarantee period. This research will show, by means of many analytical techniques and catalytic tests: 1. A comparison of the Servom...

  17. Composite coating prepared by micro-arc oxidation followed by sol-gel process and in vitro degradation properties

    International Nuclear Information System (INIS)

    Zhang Yi; Bai Kuifeng; Fu Zhenya; Zhang Caili; Zhou Huan; Wang Liguo; Zhu Shijie; Guan Shaokang; Li Dongsheng; Hu Junhua

    2012-01-01

    A Mg phosphate coating was prepared on home-developed Mg-Zn-Ca alloy to improve its anticorrosion performance in simulated body fluid (SBF, Kokubo solution). The coating was prepared by micro-arc oxidation (MAO) method at the working voltage of 120-140 V. Evident improvement of anticorrosion was obtained even through the surface was porous. To further diminish the contact with SBF, a TiO 2 layer was coated on the porous MAO layer by sol-gel dip coating followed by an annealing treatment. The coatings were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS). The electrochemical performance of the MAO and TiO 2 /MAO coated alloys was evaluated by anodic polarization measurements. The pores on Mg phosphate layer provided accommodation sites for the subsequent TiO 2 sol-gel coating which sealed the pores and hence significantly enhanced the anticorrosion while single MAO coating only improve anticorrosion within a limited range. The present result indicates that fabrication of composite coatings is a significant strategy to improve the corrosion resistance of Mg-Zn-Ca alloy and other alloys, thus enhancing the potential of using Mg alloys as bio-implants.

  18. Preparation of titanium oxide and metal titanates as powders, thin films, and microspheres by complex sol-gel process

    International Nuclear Information System (INIS)

    Deptula, A.; Olczak, T.; Lada, W.; Chmielewski, A.G.; Jakubaszek, U.; Sartowska, B.; Goretta, K.C.; Alvani, C.; Casadio, S.; Contini, V.

    2006-01-01

    Titanium oxide, for many years an important pigment, has recently been applied widely as a photocatalyst or as supports for metallic catalysts, gas sensors, photovoltaic solar cells, and water and air purification devices. Titanium oxide (TiO 2 ) and titanates based on Ba, Sr and Ca were prepared from commercial solutions of TiCl 4 and HNO 3 . The main preparation steps for the sols consisted of elimination of Cl - by distillation with HNO 3 and addition of metal hydroxides for the titanates. Resulting sols were gelled and used to: (a) prepare irregularly shaped powders by evaporation; (b) produce by a dipping technique thin films on glass, Ag or Ti supports; (c) produce spherical powders (diameters <100 μm) by solvent extraction. Results of thermal and X-ray-diffraction analyses indicated that the temperatures required to form the various compounds were lower than those necessary to form the compounds by conventional solid-state reactions and comparable to those required with use of organometallic based sol-gel methods. Temperatures of formation could be further reduced by addition of ascorbic acid (ASC) to the sols

  19. Electroluminescence of zinc oxide thin-films prepared via polymeric precursor and via sol-gel methods

    International Nuclear Information System (INIS)

    Lima, S.A.M.; Cremona, M.; Davolos, M.R.; Legnani, C.; Quirino, W.G.

    2007-01-01

    Zinc oxide (ZnO) is an electroluminescent (EL) material that can emit light in different regions of electromagnetic spectrum when electrically excited. Since ZnO is chemically stable, inexpensive and environmentally friendly material, its EL property can be useful to construct solid-state lamps for illumination or as UV emitter. We present here two wet chemical methods to prepare ZnO thin-films: the Pechini method and the sol-gel method, with both methods resulting in crystalline and transparent films with transmittance >85% at 550 nm. These films were used to make thin-film electroluminescent devices (TFELD) using two different insulator layers: lithium fluoride (LiF) or silica (SiO 2 ). All the devices exhibit at least two wide emission bands in the visible range centered at 420 nm and at 380 nm attributed to the electronic defects in the ZnO optical band gap. Besides these two bands, the device using SiO 2 and ZnO film obtained via sol-gel exhibits an additional band in the UV range centered at 350 nm which can be attributed to excitonic emission. These emission bands of ZnO can transfer their energy when a proper dopant is present. For the devices produced the voltage-current characteristics were measured in a specific range of applied voltage

  20. Antimony (V) oxide adsorbed on a silica-zirconia mixed oxide obtained by the sol-gel processing method: preparation and acid properties

    International Nuclear Information System (INIS)

    Zaitseva, Galina; Gushikem, Yoshitaka

    2002-01-01

    The preparation, degree of dispersion, thermal stability and Lewis and Broensted acidity of antimony (V) oxide adsorbed on Si O 2 /Zr O 2 mixed oxide, previously prepared by the sol-gel processing method, are described herein. The samples Si O 2 /Zr O 2 /Sb 2 O 5 , with compositions (in wt %): (a) Zr= 8.1 and Sb= 6.3; (b) Zr= 14.9 and Sb= 11.4, were prepared. Scanning electron microscopy images connected to a X-ray energy dispersive spectrometer showed that both metals, Zr and Sb, were highly dispersed in the matrices. The X-ray diffraction patterns of Si O 2 /Zr O 2 /Sb 2 O 5 heated at different temperatures showed that, up to 1023 K, the matrix was amorphous. At 1273 K a crystalline phase of Zr O 2 (baddeleyite) was observed and raising the temperature to 1573 K, crystalline phases of Si O 2 (cristobalite) and presumably of Zr O 2 /Sb 2 O 5 were observed. Using pyridine as a molecular probe, Broensted acid sites on the Si O 2 /Zr O 2 /Sb 2 O 5 matrix, heat treated up to 523 K, were shown to be very stable. (author)

  1. Antimony (V Oxide Adsorbed on a Silica-Zirconia Mixed Oxide Obtained by the Sol-Gel Processing Method: Preparation and Acid Properties

    Directory of Open Access Journals (Sweden)

    Zaitseva Galina

    2002-01-01

    Full Text Available The preparation, degree of dispersion, thermal stability and Lewis and Brphinsted acidity of antimony (V oxide adsorbed on SiO2/ZrO2 mixed oxide, previously prepared by the sol-gel processing method, are described herein. The samples SiO2/ZrO2/Sb2O5, with compositions (in wt %: (a Zr= 8.1 and Sb= 6.3; (b Zr= 14.9 and Sb= 11.4, were prepared. Scanning electron microscopy images connected to a X-ray energy dispersive spectrometer showed that both metals, Zr and Sb, were highly dispersed in the matrices. The X-ray diffraction patterns of SiO2/ZrO2/Sb2O5 heated at different temperatures showed that, up to 1023 K, the matrix was amorphous. At 1273 K a crystalline phase of ZrO2 (baddeleyite was observed and raising the temperature to 1573 K, crystalline phases of SiO2 (cristobalite and presumably of ZrO2/Sb2O5 were observed. Using pyridine as a molecular probe, Brphinsted acid sites on the SiO2/ZrO2/Sb2O5 matrix, heat treated up to 523 K, were shown to be very stable.

  2. Sol-gel preparation of cobalt manganese mixed oxides for their use as electrode materials in lithium cells

    International Nuclear Information System (INIS)

    Lavela, P.; Tirado, J.L.; Vidal-Abarca, C.

    2007-01-01

    An ethanol dehydration procedure has been used to precipitate gel-like citrate precursors containing cobalt and manganese transition metal ions. Further annealing led to the Mn x Co 3-x O 4 spinel oxide series (x: 1, 1.5, 2, 3). Annealing temperature and treatment time were also evaluated to optimize the performance of the oxides as active electrode materials in lithium cells. The manganese-cobalt mixed oxides obtained by this procedure were cubic or tetragonal phases depending on the cobalt content. SEM images showed spherical macroporous aggregates for MnCo 2 O 4 and hollow spheres for manganese oxides. The galvanostatic cycling of lithium cells assembled with these materials demonstrated a simultaneous reduction of cobalt and manganese during the first discharge and separation of cobalt- and manganese-based products on further cycling. As compared with binary manganese oxides, a notorious electrochemical improvement was observed in the mixed oxides. This behavior is a consequence of the synergistic effect of both transition metal elements, associated with the in-situ formation of a nanocomposite electrode material when cobalt is introduced in the manganese oxide composition. Values higher than 400 mAh/g were sustained after 50 cycles for MnCo 2 O 4

  3. Preparation of anti-oxidative SiC/SiO2 coating on carbon fibers from vinyltriethoxysilane by sol–gel method

    International Nuclear Information System (INIS)

    Xia Kedong; Lu Chunxiang; Yang Yu

    2013-01-01

    Highlights: ► The SiC/SiO 2 coating was prepared on carbon fibers by the sol–gel method. ► Nano-crystallites with an average diameter of 130 nm were aligned along the fiber axis uniformly. ► The oxidation resistant property of coated carbon fiber was increased with the increase of sol concentration and the heat treatment temperature. ► The oxidation activation energy of the coated carbon fiber was increased by 23% in comparison with uncoated carbon fiber. - Abstract: The anti-oxidative SiC/SiO 2 coating was prepared on carbon fibers by a sol–gel process using vinyltriethoxysilane (VTES) as the single source precursor. The derived coating was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). The oxidation resistant properties of the carbon fiber with and without coating were studied by isothermal oxidation. The results indicated that the carbothermal reduction reaction led to the decrease of SiO 2 phase and the increase of SiC phase at 1500 °C. The uniform SiC/SiO 2 coating prepared from a sol concentration of 4 wt% and heat treated at 1500 °C showed the optimal oxidation resistant property. The oxidation resistance of the carbon fiber was improved by the SiC/SiO 2 coating, and the oxidation activation energy was increased by about 23% as compared with uncoated carbon fiber.

  4. One step aqueous solution preparation of nanosize iron-doped tin oxide from SnO{sub 2}.xH{sub 2}O gel

    Energy Technology Data Exchange (ETDEWEB)

    Melghit, Khaled [Chemistry Department, College of Science, P.O. Box 36, Al-Khodh 123, Sultan Qaboos University (Oman)]. E-mail: melghit@squ.edu.om; Bouziane, Khalid [Physics Department, College of Science, P.O. Box 36, Al-Khodh 123, Sultan Qaboos University (Oman)

    2006-03-15

    Nanosized iron-doped tin oxide solid solution was prepared by mixing tin oxide gel SnO{sub 2}.xH{sub 2}O with a boiling solution of iron nitrate. The XRD data of the as-prepared and annealed sample at 773 K show that the patterns are indexed to the rutile phase without any trace of an extra phase. SEM and TEM results performed on different selected area of the samples reveal a homogeneous composition of 8 at.% of Fe content and a size of about 2 nm of the particles. The particles size was found to increase slightly with temperature; about 7 nm after 24 h at 773 K. Structural and magnetic results seem to indicate that Fe{sup 3+} substitute for Sn{sup 4+} on the as-prepared sample. The system presents some weak ferromagnetic character at room temperature.

  5. Preparation of nickel oxide thin films at different annealing temperature by sol-gel spin coating method

    Energy Technology Data Exchange (ETDEWEB)

    Abdullah, M. A. R., E-mail: ameerridhwan89@gmail.com; Mamat, M. H., E-mail: hafiz-030@yahoo.com; Ismail, A. S., E-mail: kyrin-samaxi@yahoo.com [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); Malek, M. F., E-mail: firz-solarzelle@yahoo.com [NANO-SciTech Centre (NST), Institute of Science (IOS), Universiti Teknologi MARA - UiTM, 40450 Shah Alam, Selangor (Malaysia); Alrokayan, Salman A. H., E-mail: dr.salman@alrokayan.com; Khan, Haseeb A., E-mail: khan-haseeb@yahoo.com [Chair of Targeting and Treatment of Cancer Using Nanoparticles, Deanship of Scientific Research, King Saud University (KSU), Riyadh 11451 (Saudi Arabia); Rusop, M., E-mail: rusop@salam.uitm.my [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); NANO-SciTech Centre (NST), Institute of Science (IOS), Universiti Teknologi MARA - UiTM, 40450 Shah Alam, Selangor (Malaysia)

    2016-07-06

    Preparation of NiO thin films at different annealing temperature by sol-gel method was conducted to synthesize the quality of the surface thin films. The effects of annealing temperature on the surface topology were systematically investigated. Our studies confirmed that the surface roughness of the thin films was increased whenever annealing temperature was increase. NiO thin films morphology structure analysis was confirmed by field emission scanning electron microscope. Surface roughness of the thin films was investigated by atomic force microscopy.

  6. Preparation of nickel oxide thin films at different annealing temperature by sol-gel spin coating method

    International Nuclear Information System (INIS)

    Abdullah, M. A. R.; Mamat, M. H.; Ismail, A. S.; Malek, M. F.; Alrokayan, Salman A. H.; Khan, Haseeb A.; Rusop, M.

    2016-01-01

    Preparation of NiO thin films at different annealing temperature by sol-gel method was conducted to synthesize the quality of the surface thin films. The effects of annealing temperature on the surface topology were systematically investigated. Our studies confirmed that the surface roughness of the thin films was increased whenever annealing temperature was increase. NiO thin films morphology structure analysis was confirmed by field emission scanning electron microscope. Surface roughness of the thin films was investigated by atomic force microscopy.

  7. Dependence of electrical and optical properties of sol-gel prepared undoped cadmium oxide thin films on annealing temperature

    International Nuclear Information System (INIS)

    Santos-Cruz, J.; Torres-Delgado, G.; Castanedo-Perez, R.; Jimenez-Sandoval, S.; Jimenez-Sandoval, O.; Zuniga-Romero, C.I.; Marquez Marin, J.; Zelaya-Angel, O.

    2005-01-01

    The effect of the annealing temperature (T a ) on the optical, electrical and structural properties of the undoped cadmium oxide (CdO) thin films obtained by the sol-gel method, using a simple precursor solution, was studied. All the CdO films annealed in the range from 200 to 450 deg. C are polycrystalline with (111) preferential orientation and present high optical transmission > 85% for wavelengths above 500 nm. The resistivity decreases as T a increases until it reaches a value of 6 x 10 -4 Ω cm for T a 350 deg. C. For higher temperatures the resistivity experiences a slight increase. Images obtained by atomic force microscopy show an evident incremental change of the aggregate size (clusters of grains) as T a increases. The grain size also increases when T a increases as observed in data calculated from X-ray measurements

  8. Preparation of aluminum doped zinc oxide films with low resistivity and outstanding transparency by a sol–gel method for potential applications in perovskite solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xingyue; Shen, Heping; Zhou, Chen [State Key Laboratory of New Ceramics & Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 10084 (China); Lin, Shiwei [Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources, Hainan University, Haikou 570228 (China); Li, Xin [State Key Laboratory of New Ceramics & Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 10084 (China); Zhao, Xiaochong [State Key Laboratory of New Ceramics & Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 10084 (China); Science and Technology on Surface Physics and Chemistry Laboratory, Mianyang 621907 (China); Deng, Xiangyun [Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources, Hainan University, Haikou 570228 (China); College of Physics and Electronic Information, Tianjin, Normal University, Tianjin 300387 (China); Li, Jianbao [State Key Laboratory of New Ceramics & Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 10084 (China); Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources, Hainan University, Haikou 570228 (China); Lin, Hong [State Key Laboratory of New Ceramics & Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 10084 (China)

    2016-04-30

    Highly transparent and conductive aluminum doped zinc oxide (AZO) films were prepared by sol–gel method on the glass substrates. The effects of doping concentration, annealing temperature and facing direction during annealing on the structural, electrical and optical properties of AZO films were studied by performing a series of characterizations including X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, UV–vis spectrophotometry, four-point probe method and Hall effect measurement system. The results showed that the AZO films were wurtzite crystallized with c-axis preferred orientation. A minimum resistivity of 1.8 × 10{sup −3} Ω cm and a transmittance above 90% were obtained for the film doped with 1.5 at.% aluminum, annealed at 510 °C and faced-down in the oven, which was among the best performance of the currently reported works based on sol–gel process. Moreover, energy level analysis revealed that the AZO film has a work function of 4.3 eV, exhibiting great potential in perovskite solar cell applications. - Highlights: • Highly transparent and conductive AZO films were prepared by sol–gel based process. • Different facing directions during annealing had effects on the carrier mobility. • Less aluminum ions at the grain boundary would favor the carrier transport. • The potential of AZO film in the perovskite solar cell application was discussed.

  9. Investigation of stability, consistency, and oil oxidation of emulsion filled gel prepared by inulin and rice bran oil using ultrasonic radiation.

    Science.gov (United States)

    Nourbehesht, Newsha; Shekarchizadeh, Hajar; Soltanizadeh, Nafiseh

    2018-04-01

    Inulin, rice bran oil and rosemary essential oil were used to produce high quality emulsion filled gel (EFG) using ultrasonic radiation. Response surface methodology was used to investigate the effects of oil content, inulin content and power of ultrasound on the stability and consistency of prepared EFG. The process conditions were optimized by conducting experiments at five different levels. Second order polynomial response surface equations were developed indicating the effect of variables on EFG stability and consistency. The oil content of 18%; inulin content of 44.6%; and power of ultrasound of 256 W were found to be the optimum conditions to achieve the best EFG stability and consistency. Microstructure and rheological properties of prepared EFG were investigated. Oil oxidation as a result of using ultrasonic radiation was also investigated. The increase of oxidation products and the decrease of total phenolic compounds as well as radical scavenging activity of antioxidant compounds showed the damaging effect of ultrasound on the oil quality of EFG. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Effects of concentration of reduced graphene oxide on properties of sol–gel prepared Al-doped zinc oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Ching-Tian; Wang, Fang-Hsing, E-mail: fansen@dragon.nchu.edu.tw; Chen, Wei-Chun

    2016-04-30

    Reduced-graphene-oxide-incorporated aluminum-doped zinc oxide (AZO:rGO) composite thin films were synthesized on glass substrates by using the sol–gel method. The effect of the rGO concentration (0–3 wt%) on structural, electrical, and optical properties of the composite film was investigated by X-ray diffraction, scanning electron microscopy, atomic force microscopy, Hall-effect measurement, and ultraviolet–visible spectrometry. All of the composite films showed a typical hexagonal wurtzite structure, and the films incorporated with 1 wt% rGO showed the highest (0 0 2) peak intensity. The sheet resistance of the films was effectively reduced by a factor of more than two as the rGO ratio increased from 0 to 1 wt%. However, the sheet resistance increased with a further increase in the rGO ratio. The optical transmittance of the composite film monotonically decreased with increasing the rGO ratio from 0 to 3 wt%. The average optical transmittance (400–700 nm) of the AZO:rGO thin film within 1 wt% rGO was above 81%. - Highlights: • Reduced-graphene-oxide-doped ZnO:Al composite films are synthesized by sol–gel. • All AZO:rGO thin films show a typical hexagonal wurtzite structure. • Sheet resistance of AZO:rGO(1 wt%) film decreases by a factor of more than two. • The average visible transmittance of the AZO:rGO(1 wt%) film was 81%.

  11. Elaboration and characterisation of yttrium oxide and hafnium oxide powders by the sol-gel process

    International Nuclear Information System (INIS)

    Hours, T.

    1988-01-01

    The two classical sol-gel processes, colloidal and polymeric are studied for the preparation of yttrium oxide and hafnium oxide high performance powders. In the colloidal process, controlled and reproducible conditions for the preparation of yttrium oxide and hafnium oxide sols from salts or alkoxides are developed and the hydrothermal synthesis monodisperse hafnium oxide colloids is studied. The polymeric process is studied with hafnium ethyl-hexylate, hydrolysis kinetics for controlled preparation of sols and gels is investigated. Each step of preparation is detailed and powders obtained are characterized [fr

  12. Preparation of zirconium molybdate gel generator

    International Nuclear Information System (INIS)

    Charoen, S.; Aungurarat, G.; Laohawilai, S.; Sukontpradit, W.; Jingjit, S.

    1994-01-01

    A procedure for preparation of 99mTc generator based on conversion to zirconium molybdate gel of 99Mo produced by neutron activation was reported. The gel was prepared from zirconium oxychloride solution pH 1.6, ammonium molybdate solution pH 3-5 and mole ratio of Zr:Mo 1:1 which had water content about 7-8%. Small generators containing 1-1.5 g of gel were eluted with average efficiencies of 77% and the activity peak in the first 3 ml of 10 ml of saline solution. The amount of Mo and Zr in eluates were below the acceptance limit. The gel generators of activity about 100 mCi were prepared and had the good performance in elutability and stability

  13. Structure and characterization of Sn, Al co-doped zinc oxide thin films prepared by sol–gel dip-coating process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Min-I [Institute of Materials Science and Engineering, National Central University, Taiwan (China); Laboratoire de Nanotechnologie et d' Instrumentation Optique, Institut Charles Delaunay, CNRS - UMR STMR 6279, Université de Technologie de Troyes (France); Huang, Mao-Chia [Institute of Materials Science and Engineering, National Central University, Taiwan (China); Legrand, David [Institute of Materials Science and Engineering, National Central University, Taiwan (China); Laboratoire de Nanotechnologie et d' Instrumentation Optique, Institut Charles Delaunay, CNRS - UMR STMR 6279, Université de Technologie de Troyes (France); Lerondel, Gilles [Laboratoire de Nanotechnologie et d' Instrumentation Optique, Institut Charles Delaunay, CNRS - UMR STMR 6279, Université de Technologie de Troyes (France); Lin, Jing-Chie, E-mail: jclin4046@gmail.com [Institute of Materials Science and Engineering, National Central University, Taiwan (China)

    2014-11-03

    Transparent conductive zinc oxide co-doped with tin and aluminum (TAZO) thin films were prepared via sol–gel dip-coating process. Non-toxic ethanol was used in this study instead of 2-methoxyethanol used in conventional work. Dip-coating was repeated several times to obtain relatively thick films consisting of six layers. The films were then annealed at 500 °C for 1 h in air or in vacuum and not subsequently as employed in other studies. The X-ray diffraction patterns indicated that all the samples revealed a single phase of hexagonal ZnO polycrystalline structure with a main peak of (002). The optical band gap and resistivity of the TAZO films were in the ranges of 3.28 to 3.32 eV and 0.52 to 575.25 Ω cm, respectively. The 1.0 at.% Sn, 1.0 at.% Al co-doped ZnO thin film annealed in vacuum was found to have a better photoelectrochemical performance with photocurrent density of about 0.28 mA/cm{sup 2} at a bias of 0.5 V vs. SCE under a 300 W Xe lamp illumination with the intensity of 100 mW/cm{sup 2}. Compared to the same dopant concentration but annealed in air (∼ 0.05 mA/cm{sup 2} bias 0.5 V vs. SCE), the photocurrent density of the film annealed in vacuum was 5 times higher than the film annealed in air. Through electrochemical measurements, we found that the dopant concentration of Sn plays an important role in TAZO that affected photocurrent density, stability of water splitting and anti-corrosion. - Highlights: • Al, Sn co-doped ZnO (TAZO) films was synthesized by sol–gel process. • The parameters of TAZO films were dopant concentration and annealed ambient. • The photoelectrochemical characteristics of TAZO films were investigated.

  14. Differences in the electrochemical behavior of ruthenium and iridium oxide in electrocatalytic coatings of activated titanium anodes prepared by the sol–gel procedure

    Directory of Open Access Journals (Sweden)

    VLADIMIR V. PANIĆ

    2010-10-01

    Full Text Available The electrochemical characteristics of Ti0.6Ir0.4O2/Ti and Ti0.6Ru0.4O2/Ti anodes prepared by the sol–gel procedure from the corresponding oxide sols, obtained by force hydrolysis of the corresponding metal chlorides, were compared. The voltammetric properties in H2SO4 solution indicate that Ti0.6Ir0.4O2/Ti has more pronounced pseudocapacitive characteristics, caused by proton-assisted, solid state surface redox transitions of the oxide. At potentials negative to 0.0 VSCE, this electrode is of poor conductivity and activity, while the voltammetric behavior of the Ti0.6Ru0.4O2/Ti electrode is governed by proton injection/ejection into the oxide structure. The Ti0.6Ir0.4O2/Ti electrode had a higher electrocatalytical activity for oxygen evolution, while the investigated anodes were of similar activity for chlorine evolution. The potential dependence of the impedance characteristics showed that the Ti0.6Ru0.4O2/Ti electrode behaved like a capacitor over a wider potential range than the Ti0.6Ir0.4O2/Ti electrode, with fully-developed pseudocapacitive properties at potentials positive to 0.60 VSCE. However, the impedance characteristics of the Ti0.6Ir0.4O2/Ti electrode changed with increasing potential from resistor-like to capacitor-like behavior.

  15. Structure of chitosan thermosensitive gels containing graphene oxide

    Science.gov (United States)

    Tylman, Michał; Pieklarz, Katarzyna; Owczarz, Piotr; Maniukiewicz, Waldemar; Modrzejewska, Zofia

    2018-06-01

    The supramolecular hydrogels of chitosan and graphene oxide (GO) have been prepared at temperature of the human body, by controlling the concentration of GO and ratio of chitosan to GO. During the preparation of gels the sodium β-glycerophosphate (Na-β-GP) was used as a neutralizing agent. The structure of obtained gels was determined on the basis of FTIR spectra and XRD diffraction patterns. The results of structural studies have been referenced to gels without graphene oxide. It was found that the gels crystalline structure after the addition of GO does not change. The XRD diffraction patterns are characterized by a number of peaks associated with precipitated NaCl during drying and presence of sodium β-glycerophosphate.

  16. Zinc oxide films impurified with Ti and prepared by the Sol-gel method; Peliculas de oxido de zinc impurificadas con Ti y preparadas por el metodo Sol-gel

    Energy Technology Data Exchange (ETDEWEB)

    Tirado G, S. [ESFM-IPN, 07738 Mexico D.F. (Mexico); Cazares R, J.M.; Maldonado, A. [CINVESTAV-IPN, A.P. 14-740, 07000 Mexico D.F. (Mexico)

    2006-07-01

    Titanium-doped zinc oxide thin films have been prepared on silicon substrate using the Sol-Gel technique. The structural, morphology, electrical and optical properties of such thin films were studied as a function of titanium concentration (0.5, 1 and 1.5 %) and the thin films thickness. Zinc acetate dihydrate and titanium (VI)-oxy acetylacetonate were used as precursor materials, using 2-methoxyethanol and monoethanolamine as via. The X-ray diffraction spectra show polycrystalline films in all the cases. It can see for all the thin films a preferential growth along the (002) planes where the titanium concentration and also the thin films thickness play an important rule. No structural changes are observed at all. The surface morphology studied shows as the grain size decreases when thin thickness is increases. For titanium concentration of 0.5, 1 and 1.5 % values the grains size increase also. The thin films thickness for titanium concentration of 1.5 % was 500 nm (4v), 400 nm (3v), 180 nm (2v) and 130 nm (1v), values obtained from cross-section micrographs. Highly resistive samples are obtained for substrate soda-lime even showing high transmittance. Better physical properties are required for gas sensors or semitransparent electrodes and other possible applications. (Author)

  17. Thin film transistor performance of amorphous indium–zinc oxide semiconductor thin film prepared by ultraviolet photoassisted sol–gel processing

    Science.gov (United States)

    Kodzasa, Takehito; Nobeshima, Taiki; Kuribara, Kazunori; Yoshida, Manabu

    2018-05-01

    We have fabricated an amorphous indium–zinc oxide (IZO, In/Zn = 3/1) semiconductor thin-film transistor (AOS-TFT) by the sol–gel technique using ultraviolet (UV) photoirradiation and post-treatment in high-pressure O2 at 200 °C. The obtained TFT showed a hole carrier mobility of 0.02 cm2 V‑1 s‑1 and an on/off current ratio of 106. UV photoirradiation leads to the decomposition of the organic agents and hydroxide group in the IZO gel film. Furthermore, the post-treatment annealing at a high O2 pressure of more than 0.6 MPa leads to the filling of the oxygen vacancies in a poor metal–oxygen network in the IZO film.

  18. Preparation of oxide materials from metal alkoxides

    International Nuclear Information System (INIS)

    Turevskaya, E.P.; Turova, N.Ya.; Yanovskaya, M.I.

    2000-01-01

    The results of studies on the sol-gel technologies on the basis of alkoxides are presented. The synthesis and properties of titanates zirconates, niobates, tantalates, vanadates and solid solutions on the basis of Mo, W and Bi oxides, iron oxides and high-temperature superconductors are presented. The most important aspects, determining the choice of optimal conditions for preparation of oxides of concrete compositions with required properties are pointed out. Accomplishment of the whole chain of studies made it possible to synthesize a broad range of metal alkoxides and study their properties and also carry out large-scale studies on preparation of various oxides and materials on the basis thereof, using the source base of the sol-gel method [ru

  19. The role of Ar plasma treatment in generating oxygen vacancies in indium tin oxide thin films prepared by the sol-gel process

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Deuk-Kyu [Department of Materials Science and Engineering, Yonsei University, 50 Yonsei-ro, Seoul, 03722 (Korea, Republic of); Misra, Mirnmoy; Lee, Ye-Eun [Department of BioNano Technology, Gachon University, 1342 Seong-nam dae-ro, Seong-nam si, Gyeonggi-do, 13120 (Korea, Republic of); Baek, Sung-Doo [Department of Materials Science and Engineering, Yonsei University, 50 Yonsei-ro, Seoul, 03722 (Korea, Republic of); Myoung, Jae-Min, E-mail: jmmyoung@yonsei.ac.kr [Department of Materials Science and Engineering, Yonsei University, 50 Yonsei-ro, Seoul, 03722 (Korea, Republic of); Lee, Tae Il, E-mail: t2.lee77@gachon.ac.kr [Department of BioNano Technology, Gachon University, 1342 Seong-nam dae-ro, Seong-nam si, Gyeonggi-do, 13120 (Korea, Republic of)

    2017-05-31

    Highlights: • Indium tin oxide thin film with about 41 nm thickness was obtained by the sol-gel process. • Thin film exhibited low resistivity. • Sheet resistance of thin film decreases with Ar plasma treatment time. • Ar plasma treatment on thin film does not alter the crystal structure and optical properties of the ITO thin-film. • There is no significant change in oxygen vacancies after 20 min of plasma treatment. - Abstract: Argon (Ar) plasma treatment was carried out to reduce the sheet resistance of indium tin oxide (ITO) thin films. The Ar plasma treatment did not cause any significant changes to the crystal structure, surface morphology, or optical properties of the ITO thin films. However, an X-ray photoelectron spectroscopy study confirmed that the concentration of oxygen vacancies in the film dramatically increased with the plasma treatment time. Thus, we concluded that the decrease in the sheet resistance was caused by the increase in the oxygen vacancy concentration in the film. Furthermore, to verify how the concentration of oxygen vacancies in the film increased with the Ar plasma treatment time, cumulative and continuous plasma treatments were conducted. The oxygen vacancies were found to be created by surface heating via the outward thermal diffusion of oxygen atoms from inside the film.

  20. Preparation of layered oxide Li(Co1/3Ni1/3Mn1/3)O2 via the sol-gel process

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wen; LIU Hanxing; HU Chen; ZHU Xianjun; LI Yanxi

    2008-01-01

    To obtain homogenous layered oxide Li(Co1/3Ni1/3Ni1/3Mn1/3)O2 as a lithium insertion positive electrode material,the sol-gel process using citric acid as a chelating agent was applied.The material Li(Co1/3,Ni1/3Mn1/3)O2 was synthesized at different calcination temperatures.XRD experiment indicated that the hyered Li(Co1/3Ni1/3Mn1/3)O2material could he synthesized at a lower temperature of 800℃,and the oxidation state of Co,Ni,and Mn in the cathode confirmed by XPS were +3,+2,and +4,respectively.SEM observations showed that the synthesized material could form homogenous particle morphology with the particle size of about 200nm In spite of different calcination temperatures,the charge-discharge curves of all the samples for the initial cycle were similar,and the cathode synthesized at 900℃ showed a small irreversible capacity loss of 11.24% and a high discharge capacity of 212.2 mAh.g-1 in the voltage range of 2.9-4.6 V.

  1. Preparation and characterization of hybrid materials of epoxy resin type bisphenol a with silicon and titanium oxides by sol-gel process

    Energy Technology Data Exchange (ETDEWEB)

    Carrillo C, A.; Osuna A, J. G., E-mail: acc.carrillo@gmail.com [Universidad Autonoma de Coahuila, Facultad de Ciencias Quimicas, Blvd. Venustiano Carranza y Jose Cardenas Valdes, 25000 Saltillo, Coahuila (Mexico)

    2011-07-01

    Hybrid materials were synthesized from epoxy resins as a result bisphenol type A-silicon oxide and epoxy resin bisphenol type A-titanium oxide were obtained. The synthesis was done by sol-gel process using tetraethyl orthosilicate (Teos) and titanium isopropoxide (I Ti) as inorganic precursors. The molar ratio of bisphenol A to the inorganic precursors was the studied variable. The materials were characterized by thermal analysis, infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. The hybrid nature of the materials was demonstrated through thermal analysis and infrared spectroscopy. In both systems, as the amount of alkoxide increased, the bands described above were more defined. This behavior indicates the interactions between the resin and the alkoxides. Hybrids with Teos showed a smoother and homogeneous surface in its entirety, without irregularities. Hybrids with titanium isopropoxide had low roughness. Both Teos and I Ti hybrids showed a decrease on the atomic weight percentage of carbon due to a slight reduction of the organic part on the surface. (Author)

  2. Preparation and characterization of hybrid materials of epoxy resin type bisphenol a with silicon and titanium oxides by sol-gel process

    International Nuclear Information System (INIS)

    Carrillo C, A.; Osuna A, J. G.

    2011-01-01

    Hybrid materials were synthesized from epoxy resins as a result bisphenol type A-silicon oxide and epoxy resin bisphenol type A-titanium oxide were obtained. The synthesis was done by sol-gel process using tetraethyl orthosilicate (Teos) and titanium isopropoxide (I Ti) as inorganic precursors. The molar ratio of bisphenol A to the inorganic precursors was the studied variable. The materials were characterized by thermal analysis, infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. The hybrid nature of the materials was demonstrated through thermal analysis and infrared spectroscopy. In both systems, as the amount of alkoxide increased, the bands described above were more defined. This behavior indicates the interactions between the resin and the alkoxides. Hybrids with Teos showed a smoother and homogeneous surface in its entirety, without irregularities. Hybrids with titanium isopropoxide had low roughness. Both Teos and I Ti hybrids showed a decrease on the atomic weight percentage of carbon due to a slight reduction of the organic part on the surface. (Author)

  3. Preparation of continuous alumina gel fibres by aqueous sol–gel ...

    Indian Academy of Sciences (India)

    Abstract. Continuous alumina gel fibres were prepared by sol–gel method. The spinning sol was prepared by mixing aluminum nitrate, lactic acid and polyvinylpyrrolidone with a mass ratio of 10:3:1·5. Thermogravimetry– differential scanning calorimetry (TG–DSC), Fourier transform infrared (FTIR) spectra, X-ray diffraction ...

  4. Characteristics and optical properties of iron ion (Fe{sup 3+})-doped titanium oxide thin films prepared by a sol-gel spin coating

    Energy Technology Data Exchange (ETDEWEB)

    Wang, M.C. [Faculty of Fragrance and Cosmetics, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 807, Taiwan (China); Lin, H.J. [Department of Materials Science and Engineering, National United University, 1 Lein-Da, Kung-Ching Li, Miao-Li 36003, Taiwan (China)], E-mail: hjlin@nuu.edu.tw; Yang, T.S. [Department of Materials Science and Engineering, National United University, 1 Lein-Da, Kung-Ching Li, Miao-Li 36003, Taiwan (China)

    2009-04-03

    Titanium dioxide (TiO{sub 2}) thin films doping of various iron ion (Fe{sup 3+}) concentrations have been prepared on a glass substrate by the sol-gel spin coating process. Characteristics and optical properties of TiO{sub 2} thin films doping of various Fe content were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV-vis) and spectroscopic ellipsometry. The crystalline phase of TiO{sub 2} thin films comprised only the anatase TiO{sub 2}, but the crystallinity decreased when the Fe{sup 3+} content increased from 0 to 25.0 wt%. During the Fe{sup 3+} addition to 25.0 wt%, the phase of TiO{sub 2} thin film still maintained the amorphous state. The absorption edge of TiO{sub 2} thin films shifted towards longer wavelengths (i.e. red shifted) from 355 to 415 nm when the Fe{sup 3+}-doped concentration increased from 0 to 25.0 wt%. The values of the refractive index (n), and extinction coefficient (k), decreased with an increasing Fe{sup 3+} content. Moreover, the band-gap energy of TiO{sub 2} thin films also decreased from 3.29 to 2.83 eV with an increase in the Fe{sup 3+} content from 0 to 25.0 wt%.

  5. Silica scintillating materials prepared by sol-gel methods

    International Nuclear Information System (INIS)

    Werst, D.W.; Sauer, M.C. Jr.; Cromack, K.R.; Lin, Y.; Tartakovsky, E.A.; Trifunac, A.D.

    1993-01-01

    Silica was investigated as a rad-hard alternative to organic polymer hosts for organic scintillators. Silica sol-gels were prepared by hydrolysis of tetramethoxysilane in alcohol solutions. organic dyes were incorporated into the gels by dissolving in methanol at the sol stage of gel formation. The silica sol-gel matrix is very rad-hard. The radiation stability of silica scintillators prepared by this method is dye-limited. Transient radioluminescence was measured following excitation with 30 ps pulses of 20 MeV electrons

  6. Preparation of an efficient humidity indicating silica gel from rice ...

    Indian Academy of Sciences (India)

    Administrator

    Department of Ceramic Engineering, National Institute of Technology, Rourkela 769 008, ... An efficient humidity indicating silica gel was prepared using rice husk ash as a raw material via ... white or colourless and shows no changes of colour.

  7. Preparation, microstructure and properties of yttrium aluminum garnet fibers prepared by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Li Chengshun [Key Laboratory for Liquid Structure and Heredity of Materials of Ministry of Education, Shandong University, Jinan 250061 (China); Zhang Yujun [Key Laboratory for Liquid Structure and Heredity of Materials of Ministry of Education, Shandong University, Jinan 250061 (China)], E-mail: yujunzhangcn@sdu.edu.cn; Gong Hongyu; Zhang Jingde; Nie Lifang [Key Laboratory for Liquid Structure and Heredity of Materials of Ministry of Education, Shandong University, Jinan 250061 (China)

    2009-01-15

    Yttrium aluminum garnet (YAG) fiber was prepared by sol-gel method using water as the solvent. The spinnable YAG sol was synthesized using Al powder, Y(CH{sub 3}COOH){sub 3}.4H{sub 2}O and HCl as precursors, polyethylene oxide as viscosity adjusting agent. Gel fibers with diameter of 5-10 {mu}m were prepared from the YAG sol by using centrifugal spinning technique. YAG crystalline fibers were obtained by drying gel fibers and heat-treating at selected temperature. TG/DTA analysis showed an exotherm at 906 deg. C attributed to formation of YAG phase and weight loss of 45% at 1000 deg. C. XRD and FT-IR analysis showed that phase-pure YAG can be formed at 900 deg. C, and no other intermediate was observed. The grain size of YAG fibers increased from 25 to 220 nm and tensile strength decreased rapidly from 970 to 380 MPa when the sintering temperature increased from 900 to 1550 deg. C.

  8. Application of gel microsphere processes to preparation of Sphere-Pac nuclear fuel

    International Nuclear Information System (INIS)

    Haas, P.A.; Notz, K.J.; Spence, R.D.

    1978-01-01

    Sphere-Pac fabrication of nuclear fuels using two or more sizes of oxide or carbide spheres is ideally suited to nonproliferation-fuel cycles and remote refabrication. The sizes and compositions of spheres necessary for such fuel cycles have not been commonly prepared; therefore, modifications of sol-gel processes to meet these requirements are being developed and demonstrated

  9. PREPARATION AND PROPERTIES OF COMPOUND ARNEBIAE RADIX MICROEMULSION GEL.

    Science.gov (United States)

    Chen, Jing; He, Yanping; Gao, Ting; Zhang, Licheng; Zhao, Yuna

    2017-01-01

    Compound Arnebiae radix oil has been clinically applied to treat burns and scalds for a long time. However, it is unstable and inconvenient to use. The aim of this study was to prepare a compound Arnebiae radix microemulsion gel for transdermal delivery system and evaluate its characteristics. Based on the solubility of Shikonin, the active component of Arnebiae radix and the results of phase studies, adequate ratio of each component in microemulsion was determined. The optimized microemulsion gel was prepared using Carbomer 940. The gels were characterized in terms of appearance, preliminary stability test and the content of Shikonin in the compound Arnebiae radix microemulsion gel with HPLC analysis. The optimized conditions for preparing microemulsion were Tween-80, glycerin, isopropyl myristate (IPM) with the ratio of 6:3:2. The optimal microemulsion gel was obtained with Carbomer 940 (1.0%). The prepared compound Arnebiae radix microemulsion gel showed good stability over time. It is more convenience in application than the previous used formulations.

  10. Novel macroporous amphoteric gels: Preparation and characterization

    Directory of Open Access Journals (Sweden)

    S. Kudaibergenov

    2012-05-01

    Full Text Available Macroporous amphoteric gels based on allylamine, methacrylic acid and acrylamide crosslinked by N,N'-methylenebisacrylamide were synthesized by radical copolymerization of monomers in cryoconditions. The composition of cryogels was determined by combination of potentiometric and conductimetric titrations. The morphology of cryogels was evaluated by scanning electron microscope (SEM. Cryogels exhibited sponge-like porous structure with pore size ranging from 50 to 200 μm. The values of the isoelectric points (IEPs determined from the swelling experiments arranged between 3.5 and 4.3. The high adsorption-desorption capacity of amphoteric cryogels with respect to mM and trace concentrations of copper, nickel, and cobalt ions was demonstrated. It was shown that the macroporous amphoteric cryogels are able to adsorb up to 99.9% of copper, nickel, and cobalt ions from 10–3 mol•L–1 aqueous solution.

  11. Preparation and characterization of bismuth ruthenate pyrochlore via solid state reaction and sol-gel methods

    Directory of Open Access Journals (Sweden)

    Mayuree Sansernnivet

    2010-01-01

    Full Text Available Bismuth ruthenate pyrochlores, potential cathode materials for intermediate temperature solid oxide fuel cells(ITSOFCs, were prepared via solid-state and sol-gel method. Effects of the preparation routes and conditions on the phase and microstructures of the materials were investigated in this study using XRD and SEM. The study showed that the preparation method and the adding sequence of the starting meterials have a significant effect on the crystal phase and the particle size obtained. Sol-gel synthesis could yield a material with only pyrochlore structure, i.e. Bi2Ru2O7, while the solid state method yielded powder with a small amount of the secondary RuO2 phase. The sol-gel synthesis resulted in materialswith a finer particle size (~0.3-1.0 μm compared to powder synthesized via the solid state reaction method.

  12. Comparative study of nano copper aluminate spinel prepared by sol–gel and modified sol–gel techniques: Structural, electrical, optical and catalytic studies

    International Nuclear Information System (INIS)

    Kumar, R. Thinesh; Suresh, P.; Selvam, N. Clament Sagaya; Kennedy, L. John; Vijaya, J. Judith

    2012-01-01

    Highlights: ► A modified sol–gel method for the preparation of nano CuAl 2 O 4 spinel using ethylenediamine was studied. ► Role of ethylenediamine in enhancing the structural, electrical, optical and catalytic properties of copper aluminate is highlighted. ► Effect of preparation method on the activity and selectivity of the samples on the oxidation of benzyl alcohol by CuAl 2 O 4 is studied. - Abstract: The effect of ethylenediamine addition in the sol–gel method for the preparation of nano CuAl 2 O 4 spinel for the enhancement in their structural, electrical, optical and catalytic properties was investigated. The samples were prepared by two different methods: sol–gel and modified sol–gel technique using ethylenediamine. X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), scanning electron microscopy (SEM), high resolution-transmission electron microscopy (HR-TEM), energy dispersive X-ray analysis (EDX), nitrogen adsorption/desorption isotherms, temperature dependent conductance measurements, thermoelectric power (TEP) measurements and UV–visible diffuse reflectance (UV–vis-DRS) spectra were used to characterize the samples prepared. CuAl 2 O 4 prepared by modified sol–gel technique was found to possess a higher surface area, lower crystallite size, lower activation energy and high porosity than the one prepared by sol–gel method which in turn lead to the improved performance of it towards the selective oxidation of benzyl alcohol to benzaldehyde. Effect of solvent on the catalytic oxidation of benzyl alcohol by the nano CuAl 2 O 4 prepared by modified sol–gel technique was also investigated.

  13. Sol-Gel Derived, Nanostructured Oxide Lubricant Coatings

    National Research Council Canada - National Science Library

    Taylor, Douglas

    2000-01-01

    In this program, we deposited oxide coatings of titanium and nickel by wet-chemical deposition methods, also referred to as sol-gel, which showed excellent tribological properties in previous investigations...

  14. Preparation of zirconium molybdate gel for 99mTc gel generator

    International Nuclear Information System (INIS)

    Aliludin, Z.; Ohkubo, Masatake; Kushita, Kouhei

    1988-09-01

    Zirconium molybdate gel has excellent characteristics for use as column matrix material of 99m Tc generators. In this work, zirconium molybdate gels were prepared under different conditions; pH's of molybdate solutions from 2.5 to 7.0, Mo:Zr molar ratios from 0.7:1.0 to 1.3:1.0, drying temperatures from an ambient temperature to 200 deg C, and drying times from 1 h to 25 h. Contents of water, nitrate, molybdenum and zirconium were measured to examine the fundamental conditions in gel preparation. The Mo:Zr molar ratio was 1.0:1.0 for the most of gels obtained. A 99m Tc generator was prepared with an amorphous zirconium molybdate containing a tracer level of 99 Mo as column matrix material. Elution of 99m Tc was rapid and the average elution efficiency was 90 % for 6 ml elutions. Contents of radionuclidic impurities, Zr and Mo in the eluates, were low enough to meet the pharmacopoeia requirements for human use. (author)

  15. Sol-gel/hydrothermal synthesis of mixed metal oxide of Titanium and ...

    African Journals Online (AJOL)

    Mixed metal oxides of titanium and zinc nanocomposites were prepared through sol-gel method under hydrothermal condition using titanium oxy-(1, 2 - pentadione) and zinc acetate without hazardous additives. The resulting composites were characterized by X-Ray Diffractometer (XRD), Scanning Electron Microscope ...

  16. Improving the scratch resistance of sol-gel metal oxide coatings cured at 250 C through use of thermogenerated amines

    NARCIS (Netherlands)

    Langanke, J.; Arfsten, N.; Buskens, P.; Habets, R.; Klankermayer, J.; Leitner, W.

    2013-01-01

    Scratch resistant sol-gel metal oxide coatings typically require a thermal post-treatment step (curing process) at temperatures between 400 and 700 C. In this report, we demonstrate that the in situ generation of amines within sol-gel films facilitates the preparation of scratch resistant metal

  17. Preparation of silica by sol-gel method using formamide

    Directory of Open Access Journals (Sweden)

    R.F.S. Lenza

    2001-07-01

    Full Text Available In this work we obtained microporous and mesoporous silica gels by sol-gel processing. Tetraethylortosilicate (TEOS was used as precursor. Nitric acid and hydrofluoric acid were used as catalysts. In order to study the affect of formamide as drying additive, we used a molar ratio alkoxide/formamide of 1/1. The performance of formamide in obtaining crack-free gels was evaluated through monolithicity measurements. The structural evolution occurring in the interconnected network of the gels during thermal treatment was monitored by Fourier transform infrared spectroscopy (FTIR, shrinkage and density measurements and nitrogen gas sorption. We noted that in the presence of formamide, the Si-O-Si bonds are stronger and belong to a more cross-linked structure. The samples obtained in the presence of formamide have larger pore volume and its pore structure is in the range of mesoporosity. The samples obtained without additive are microporous. Formamide allowed the preparation of crack-free silica gels stabilized at high temperatures.

  18. Lithium ceramics: sol-gel preparation and tritium release

    International Nuclear Information System (INIS)

    Renoult, O.

    1994-04-01

    Ceramics based on lithium aluminate (LiA1O 2 ), lithium zirconate (Li 2 ZrO 3 ) and lithium titanate (Li 2 TiO 3 ) are candidates as tritium breeder blanket materials for forthcoming nuclear fusion reactors. Lithium silico-aluminate Li 4+x A1 4-3x Si 2x O 8 (0 ≤ x ≤ 0,25) powders were synthetized from alkoxyde-hydroxyde sol-gel route. By direct sintering at 850-1100 deg C (without prior calcination), ceramics with controlled stoichiometry and homogenous microstructure were obtained. We have also prepared, using a comparable method, Li 2 Zr 1-x Ti x O 3 (x = 0, x = 0,1 et x = 1) materials. All these ceramics, with different microstructures and compositions, have been tested in out-of-reactor experiments. Concerning lithium aluminate microporous ceramics, the silicon substitution leads to a significant improvement of the tritrium release. Classical models taking into account independent surface mechanisms are not able to describe correctly the observed tritium release kinetics. We show, using a simple model, that the release kinetics is in fact limited by an intergranular diffusion followed by a desorption. The delay in tritium release, which occurs when the ceramic compacity increases, is explained in terms of an enhancement of the ionic T + diffusion path length. The energy required for desorption includes a leading term independent of hydrogen contained in the sweep gas. This term is attributed to the limiting recombination step of T + in molecular species HTO. For similar microstructures, the facility of tritium release for the different studied materials is explained by three properties: the crystal structure of the ceramic, the acidity of oxides and finally the presence of electronic non-stoichiometric defects. (author). 89 refs., 50 figs., 2 tabs., 1 annexe

  19. Indium oxide octahedrons based on sol–gel process enhance room temperature gas sensing performance

    Energy Technology Data Exchange (ETDEWEB)

    Mu, Xiaohui [Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, Shandong (China); Chen, Changlong, E-mail: chem.chencl@hotmail.com [Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, Shandong (China); Han, Liuyuan [Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, Shandong (China); Shao, Baiqi [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Wei, Yuling [Instrumental Analysis Center, Qilu University of Technology, Jinan 250353, Shandong (China); Liu, Qinglong; Zhu, Peihua [Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, Shandong (China)

    2015-07-15

    Highlights: • In{sub 2}O{sub 3} octahedron films are prepared based on sol–gel technique for the first time. • The preparation possesses merits of low temperature, catalyst-free and large production. • It was found that the spin-coating process in film fabrication was key to achieve the octahedrons. • The In{sub 2}O{sub 3} octahedrons could significantly enhance room temperature NO{sub 2} gas sensing performance. - Abstract: Indium oxide octahedrons were prepared on glass substrates through a mild route based on sol–gel technique. The preparation possesses characteristics including low temperature, catalyst-free and large production, which is much distinguished from the chemical-vapor-deposition based methods that usually applied to prepare indium oxide octahedrons. Detailed characterization revealed that the indium oxide octahedrons were single crystalline, with {1 1 1} crystal facets exposed. It was found that the spin-coating technique was key for achieving the indium oxide crystals with octahedron morphology. The probable formation mechanism of the indium oxide octahedrons was proposed based on the experiment results. Room temperature NO{sub 2} gas sensing measurements exhibited that the indium oxide octahedrons could significantly enhance the sensing performance in comparison with the plate-like indium oxide particles that prepared from the dip-coated gel films, which was attributed to the abundant sharp edges and tips as well as the special {1 1 1} crystal facets exposed that the former possessed. Such a simple wet-chemical based method to prepare indium oxide octahedrons with large-scale production is promising to provide the advanced materials that can be applied in wide fields like gas sensing, solar energy conversion, field emission, and so on.

  20. Indium oxide octahedrons based on sol–gel process enhance room temperature gas sensing performance

    International Nuclear Information System (INIS)

    Mu, Xiaohui; Chen, Changlong; Han, Liuyuan; Shao, Baiqi; Wei, Yuling; Liu, Qinglong; Zhu, Peihua

    2015-01-01

    Highlights: • In 2 O 3 octahedron films are prepared based on sol–gel technique for the first time. • The preparation possesses merits of low temperature, catalyst-free and large production. • It was found that the spin-coating process in film fabrication was key to achieve the octahedrons. • The In 2 O 3 octahedrons could significantly enhance room temperature NO 2 gas sensing performance. - Abstract: Indium oxide octahedrons were prepared on glass substrates through a mild route based on sol–gel technique. The preparation possesses characteristics including low temperature, catalyst-free and large production, which is much distinguished from the chemical-vapor-deposition based methods that usually applied to prepare indium oxide octahedrons. Detailed characterization revealed that the indium oxide octahedrons were single crystalline, with {1 1 1} crystal facets exposed. It was found that the spin-coating technique was key for achieving the indium oxide crystals with octahedron morphology. The probable formation mechanism of the indium oxide octahedrons was proposed based on the experiment results. Room temperature NO 2 gas sensing measurements exhibited that the indium oxide octahedrons could significantly enhance the sensing performance in comparison with the plate-like indium oxide particles that prepared from the dip-coated gel films, which was attributed to the abundant sharp edges and tips as well as the special {1 1 1} crystal facets exposed that the former possessed. Such a simple wet-chemical based method to prepare indium oxide octahedrons with large-scale production is promising to provide the advanced materials that can be applied in wide fields like gas sensing, solar energy conversion, field emission, and so on

  1. A Review of Photocatalysts Prepared by Sol-Gel Method for VOCs Removal

    Directory of Open Access Journals (Sweden)

    Ting Ke Tseng

    2010-05-01

    Full Text Available The sol-gel process is a wet-chemical technique (chemical solution deposition, which has been widely used in the fields of materials science, ceramic engineering, and especially in the preparation of photocatalysts. Volatile organic compounds (VOCs are prevalent components of indoor air pollution. Among the approaches to remove VOCs from indoor air, photocatalytic oxidation (PCO is regarded as a promising method. This paper is a review of the status of research on the sol-gel method for photocatalyst preparation and for the PCO purification of VOCs. The review and discussion will focus on the preparation and coating of various photocatalysts, operational parameters, and will provide an overview of general PCO models described in the literature.

  2. Sol-gel applications for ceramic membrane preparation

    Science.gov (United States)

    Erdem, I.

    2017-02-01

    Ceramic membranes possessing superior properties compared to polymeric membranes are more durable under severe working conditions and therefore their service life is longer. The ceramic membranes are composed of some layers. The support is the layer composed of coarser ceramic structure and responsible for mechanical durability under filtration pressure and it is prepared by consolidation of ceramic powders. The top layer is composed of a finer ceramic micro-structure mainly responsible for the separation of components present in the fluid to be filtered and sol-gel method is a versatile tool to prepare such a tailor-made ceramic filtration structure with finer pores. Depending on the type of filtration (e.g. micro-filtration, ultra-filtration, nano-filtration) aiming separation of components with different sizes, sols with different particulate sizes should be prepared and consolidated with varying precursors and preparation conditions. The coating of sol on the support layer and heat treatment application to have a stable ceramic micro-structure are also important steps determining the final properties of the top layer. Sol-gel method with various controllable parameters (e.g. precursor type, sol formation kinetics, heat treatment conditions) is a practical tool for the preparation of top layers of ceramic composite membranes with desired physicochemical properties.

  3. MUCOADHESIVE GEL WITH IMMOBILIZED LYSOZYME: PREPARATION AND PROPERTIES

    Directory of Open Access Journals (Sweden)

    Dekina S. S.

    2015-08-01

    Full Text Available The study of non-covalent immobilized lysozyme, as well as physico-chemical and biochemical properties of obtained mucoadhesive gel was the aim of the research. Lysozyme activity was determined by bacteriolytic method (Micrococcus lysodeikticus cells acetone powder was a substrate. Lysozyme immobilization was conducted by the method of entrapment in gel. Enzyme carrier interaction was studied by viscometric, spectrophotometric and spectrofluorimetric methods. Mucoadhesive gel with immobilized lysozyme, possessing antiinflammatory and antimicrobial activities, was prepared. Due to immobilization, protein-polymer complex with the original enzymatic activity was formed. The product is characterized by high mucoadhesive properties, quantitative retaining of protein and bacteriolytic activity, prolonged release of the enzyme, improved biochemical characteristics (extended pH-activity profile, stability in acidic medium and during storage for 2 years, and it is perspective for further studies. The proposed method for lysozyme immobilization in the carboxymethyl cellulose sodium salt gel allows to obtain a stable, highly efficient product, with high adhesive properties for attachment to the mucous membranes, that is promising for use in biomedicine.

  4. Innovative Sol-Gel Routes for the Bottom-up Preparation of Heterogeneous Catalysts.

    Science.gov (United States)

    Debecker, Damien P

    2017-12-11

    Heterogeneous catalysts can be prepared by different methods offering various levels of control on the final properties of the solid. In this account, we exemplify bottom-up preparation routes that are based on the sol-gel chemistry and allow to tailor some decisive properties of solid catalysts. First, an emulsion templating strategy is shown to lead to macrocellular self-standing monoliths with a macroscopic 3D structure. The latter can be used as catalyst or catalyst supports in flow chemistry, without requiring any subsequent shaping step. Second, the aerosol-assisted sol-gel process allows for the one-step and continuous production of porous mixed oxides. Tailored textural properties can be obtained together with an excellent control on composition and homogeneity. Third, the application of non-hydrolytic sol-gel routes, in the absence of water, leads to mixed oxides with outstanding textural properties and with peculiar surface chemistry. In all cases, the resulting catalytic performance can be correlated with the specificities of the preparation routes presented. This is exemplified in catalytic reactions in the fields of biomass conversion, petro chemistry, enantioselective organic synthesis, and air pollution mitigation. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Characterization of composites prepared by sol-gel process through positrons lifetime spectroscopy

    International Nuclear Information System (INIS)

    Sousa, Edesia M.B. de; Magalhaes, Welligton F. de; Mohallem, Nelcy D.S.

    1996-01-01

    Si O 2 matrix were prepared by sol-gel method using TEOS, ethanol and H 2 O in a 1/3/10 mol ratio, with HCl and HF as catalysts. This silica gels were doped with copper and titanium adding Cu Cl and titanium tetra-iso-prop oxide in the starting solution, during agitation. The samples were prepared in monolithic shape, were dried at 110 deg C for 24 hours and thermally treated for 2 hours at 500, 900 and 1100 deg C. The structural evolution was studied y x-ray diffraction, mercury porosimetry and pycnometry. In this work, it was also used the Position Annihilation Lifetime Spectroscopy which have been used, nowadays, as a microscopic probe in order to investigate the free volume in zeolites, polymers and metallic alloy. All the samples have shown a stable pore structure until 900 deg C and a strong densification process at 1100 deg C. (author)

  6. Effect of annealing temperature on optical properties of binary zinc tin oxide nano-composite prepared by sol-gel route using simple precursors: structural and optical studies by DRS, FT-IR, XRD, FESEM investigations.

    Science.gov (United States)

    Habibi, Mohammad Hossein; Mardani, Maryam

    2015-02-25

    Binary zinc tin oxide nano-composite was synthesized by a facile sol-gel method using simple precursors from the solutions consisting of zinc acetate, tin(IV) chloride and ethanol. Effect of annealing temperature on optical and structural properties was investigated using X-ray diffraction (XRD), diffuse reflectance spectra (DRS), field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). XRD results revealed the existence of the ZnO and SnO2 phases. FESEM results showed that binary zinc tin oxide nano-composites ranges from 56 to 60 nm in diameter at 400°C and 500°C annealing temperatures respectively. The optical band gap was increased from 2.72 eV to 3.11 eV with the increasing of the annealing temperature. FTIR results confirmed the presence of zinc oxide and tin oxide and the broad absorption peaks at 3426 and 1602 cm(-1) can be ascribed to the vibration of absorptive water, and the absorption peaks at 546, 1038 and 1410 cm(-1) are due to the vibration of Zn-O or Sn-O groups in binary zinc tin oxide. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Excimer laser processing of ZnO thin films prepared by the sol-gel process

    International Nuclear Information System (INIS)

    Winfield, R.J.; Koh, L.H.K.; O'Brien, Shane; Crean, Gabriel M.

    2007-01-01

    ZnO thin films were prepared on soda-lime glass from a single spin-coating deposition of a sol-gel prepared with anhydrous zinc acetate [Zn(C 2 H 3 O 2 ) 2 ], monoethanolamine [H 2 NC 2 H 4 OH] and isopropanol. The deposited films were dried at 50 and 300 deg. C. X-ray analysis showed that the films were amorphous. Laser annealing was performed using an excimer laser. The laser pulse repetition rate was 25 Hz with a pulse energy of 5.9 mJ, giving a fluence of 225 mJ cm -2 on the ZnO film. Typically, five laser pulses per unit area of the film were used. After laser processing, the hexagonal wurtzite phase of zinc oxide was observed from X-ray diffraction pattern analysis. The thin films had a transparency of greater than 70% in the visible region. The optical band-gap energy was 3.454 eV. Scanning electron microscopy and profilometry analysis highlighted the change in morphology that occurred as a result of laser processing. This comparative study shows that our sol-gel processing route differs significantly from ZnO sol-gel films prepared by conventional furnace annealing which requires temperatures above 450 deg. C for the formation of crystalline ZnO

  8. Preparation of supramolecular hydrogel-enzyme hybrids exhibiting biomolecule-responsive gel degradation.

    Science.gov (United States)

    Shigemitsu, Hajime; Fujisaku, Takahiro; Onogi, Shoji; Yoshii, Tatsuyuki; Ikeda, Masato; Hamachi, Itaru

    2016-09-01

    Hydrogelators are small, self-assembling molecules that form supramolecular nanofiber networks that exhibit unique dynamic properties. Development of supramolecular hydrogels that degrade in response to various biomolecules could potentially be used for applications in areas such as drug delivery and diagnostics. Here we provide a synthetic procedure for preparing redox-responsive supramolecular hydrogelators that are used to create hydrogels that degrade in response to oxidizing or reducing conditions. The synthesis takes ∼2-4 d, and it can potentially be carried out in parallel to prepare multiple hydrogelator candidates. This described solid-phase peptide synthesis protocol can be used to produce previously described hydrogelators or to construct a focused molecular library to efficiently discover and optimize new hydrogelators. In addition, we describe the preparation of redox-responsive supramolecular hydrogel-enzyme hybrids that are created by mixing aqueous solutions of hydrogelators and enzymes, which requires 2 h for completion. The resultant supramolecular hydrogel-enzyme hybrids exhibit gel degradation in response to various biomolecules, and can be rationally designed by connecting the chemical reactions of the hydrogelators with enzymatic reactions. Gel degradation in response to biomolecules as triggers occurs within a few hours. We also describe the preparation of hydrogel-enzyme hybrids arrayed on flat glass slides, enabling high-throughput analysis of biomolecules such as glucose, uric acid, lactate and so on by gel degradation, which is detectable by the naked eye. The protocol requires ∼6 h to prepare the hydrogel-enzyme hybrid array and to complete the biomolecule assay.

  9. Process for preparing polyolefin gel articles as well as for preparing herefrom articles having a high tensile strength and modulus

    NARCIS (Netherlands)

    1990-01-01

    A process is described for the preparation of highly stretchable high-molecular weight polyolefin gel articles and polyolefin gel articles prepared therefrom having combined high tensile strength and high modulus, wherein an initial shaped article of the polyolefin is exposed to or contacted with a

  10. Preparation and Properties of Polyester-Based Nanocomposite Gel Coat System

    Directory of Open Access Journals (Sweden)

    P. Jawahar

    2006-01-01

    Full Text Available Nanocomposite gel coat system is prepared using unsaturated polyester resin with aerosil powder, CaCO3, and organoclay. The influence of organoclay addition on mechanical and water barrier properties of gel coat system is studied for different amount (1, 2, and 3 wt % of organoclay. The nanolevel incorporation of organoclay improves the mechanical and water barrier properties of nanocomposite gel coat system. The nanocomposite gel coat system exhibits 55% improvement in tensile modulus and 25% improvement in flexural modulus. There is a 30% improvement in impact property of nanocomposite gel coat system. The dynamic mechanical analysis shows a slight increase in glass transition temperature for nanocomposite gel coat system.

  11. Novel Materials through Non-Hydrolytic Sol-Gel Processing: Negative Thermal Expansion Oxides and Beyond

    Directory of Open Access Journals (Sweden)

    Cora Lind

    2010-04-01

    Full Text Available Low temperature methods have been applied to the synthesis of many advanced materials. Non-hydrolytic sol-gel (NHSG processes offer an elegant route to stable and metastable phases at low temperatures. Excellent atomic level homogeneity gives access to polymorphs that are difficult or impossible to obtain by other methods. The NHSG approach is most commonly applied to the preparation of metal oxides, but can be easily extended to metal sulfides. Exploration of experimental variables allows control over product stoichiometry and crystal structure. This paper reviews the application of NHSG chemistry to the synthesis of negative thermal expansion oxides and selected metal sulfides.

  12. Sol-Gel/Hydrothermal Synthesis of Mixed Metal Oxide

    African Journals Online (AJOL)

    Keywords: Nanocomposites, Titanium dioxide, Zinc oxide, Particle sizes, Optical property, X-Ray Diffraction. ABSTRACT. 321 .... holey carbon support film were used to prepare the samples for SEM .... absorb photons in the visible range of the.

  13. Preparation of poly(3-hydroxybutyrate)/carboxymethyl cellulose acetate butyrate blends using gel formation

    International Nuclear Information System (INIS)

    Gomes, A.L.; Rodrigues, G.V.; Goncalves, M.C.

    2009-01-01

    This study investigates poly(3-hydroxybutyrate) (PHB) gel formation with a binary combination of solvents and its use on the preparation of PHB and carboxymethyl cellulose acetate butyrate (CMCAB) blends. The gel preparation method was compared to a precipitation method followed by hot pressing. The results from DSC and X-ray diffractions showed that both methodologies produced blends with very similar thermal properties and crystallization behavior. Scanning electron microscopy indicated better homogeneity in gel formation blends. Apart from this, the gel formation methodology provided new ways to prepare immiscible blends with the advantage of using friendlier solvents. (author)

  14. Characterizations of maghemite thin films prepared by a sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Lau, L. N., E-mail: lau7798@gmail.com; Ibrahim, N. B., E-mail: baayah@ukm.edu.my [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor. Malaysia (Malaysia)

    2015-09-25

    Iron is one of the abundant elements of Mother Nature and its compound, iron oxide is an interesting material to study since its discovery in the form of magnetite. It can exist in many phases such as hematite and maghemite, this unique nature has put it as a potential candidate in various applications. The aim of this work is to study the influence of different precursor concentrations on the microstructural and magnetic properties of iron oxide thin film. All samples were prepared via the sol-gel method followed by a spin coating technique on quartz substrates. Iron oxide films were confirmed as maghemite phase from X-ray diffraction patterns. The film morphology was examined by a field emission scanning electron microscope and it showed non-systematic value of average grain size and film thickness throughout the study. Hysteresis loop further confirmed that maghemite is a magnetic material when it was characterized by a vibrating sample magnetometer. The coercivity did not show any correlation with molarity. Nevertheless, it increased as the precursor concentration of the film increased due to the domain behaviour. In conclusion, maghemite thin films were successfully synthesized by the sol-gel method with different precursor concentrations in this work.

  15. Preparation and Optoelectrical Properties of p-CuO/n-Si Heterojunction by a Simple Sol-Gel Method

    Science.gov (United States)

    He, Bo; Xu, Jing; Ning, Huanpo; Zhao, Lei; Xing, Huaizhong; Chang, Chien-Cheng; Qin, Yuming; Zhang, Lei

    The Cuprous oxide (CuO) thin film was prepared on texturized Si wafer by a simple sol-gel method to fabricate p-CuO/n-Si heterojunction photoelectric device. The novel sol-gel method is very cheap and convenient. The structural, optical and electrical properties of the CuO film were studied by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), X-ray photoelectron spectroscopy (XPS), UV-Vis spectrophotometer and Hall effect measurement. A good nonlinear rectifying behavior is obtained for the p-CuO/n-Si heterojunction. Under reverse bias, good photoelectric behavior is obtained.

  16. Syntheses of rare-earth metal oxide nanotubes by the sol-gel method assisted with porous anodic aluminum oxide templates

    International Nuclear Information System (INIS)

    Kuang Qin; Lin Zhiwei; Lian Wei; Jiang Zhiyuan; Xie Zhaoxiong; Huang Rongbin; Zheng Lansun

    2007-01-01

    In this paper, we report a versatile synthetic method of ordered rare-earth metal (RE) oxide nanotubes. RE (RE=Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb) oxide nanotubes were successfully prepared from corresponding RE nitrate solution via the sol-gel method assisted with porous anodic aluminum oxide (AAO) templates. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM, and X-ray diffraction (XRD) have been employed to characterize the morphology and composition of the as-prepared nanotubes. It is found that as-prepared RE oxides evolve into bamboo-like nanotubes and entirely hollow nanotubes. A new possible formation mechanism of RE oxide nanotubes in the AAO channels is proposed. These high-quantity RE oxide nanotubes are expected to have promising applications in many areas such as luminescent materials, catalysts, magnets, etc. - Graphical abstract: A versatile synthetic method for the preparation of ordered rare-earth (RE) oxide nanotubes is reported, by which RE (RE=Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb) oxide nanotubes were successfully prepared from corresponding RE nitrate solution via the sol-gel method assisted with porous anodic aluminum oxide (AAO) templates

  17. Ionic conductivity of Bi{sub 2}Ni{sub x}V{sub 1−x}O{sub 5.5−3x/2} (0.1 ≤ x ≤ 0.2) oxides prepared by a low temperature sol-gel route

    Energy Technology Data Exchange (ETDEWEB)

    Rusli, Rolan; Patah, Aep, E-mail: ismu@chem.itb.ac.id; Prijamboedi, Bambang, E-mail: ismu@chem.itb.ac.id; Ismunandar, E-mail: ismu@chem.itb.ac.id [Inorganic and Physical Chemistry Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia); Abrahams, Isaac [Materials Research Institute, School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom)

    2014-03-24

    Solid oxides fuel cells (SOFCs) is one technology that could contribute toward future sustainable energy. One of the most important components of an SOFC is the electrolyte, which must have high ionic conductivity. Cation substitution of vanadium in Bi{sub 4}V{sub 2}O{sub 11} yields a family of fast oxide ion conducting solids known collectively as the BIMEVOXes (bismuth metal vanadium oxide), which have the potential to be applied as electrolytes in SOFCs. The purpose of this work is to study the effect of Ni concentration, when used as a dopant, on the ionic conductivity of Bi{sub 2}Ni{sub x}V{sub 1−x}O{sub 5.5−3x/2} (BINIVOX) oxides (0.1 ≤ x ≤ 0.2) when prepared by a sol gel method. The gels were calcined at 600 °C for 24 h to produce pure BINIVOX. These oxides were found to exhibit the γ-phase structure with tetragonal symmetry in space group I4/mmm. Ionic conductivity of BINIVOX at 300 °C were 6.9 × 10{sup −3} S cm{sup −1}, 1.2 × 10{sup −3} S cm{sup −1}, and 8.2 × 10{sup −4} S cm{sup −1}, for x = 0.1; 0.15; and 0.2; respectively; and at 600 °C were 1.1 × 10{sup −1} S cm{sup −1}, 5.3 × 10{sup −2} S cm{sup −1}, and 2.8 ×10{sup −2} S cm{sup −1}, for x = 0.1; 0.15; and 0.2; respectively.

  18. Preparation And Evaluation Of Fluconazole Gels | Abdel-Mottaleb ...

    African Journals Online (AJOL)

    Gels dosage forms are successfully used as drug delivery systems considering their ability to control drug release and to protect medicaments from a hostile environment. Thus, it was desired in this study to formulate fluconazole into a gel that could be used locally in the treatment of different skin fungal infections. Cellulose ...

  19. Preparation of Natural Rubber (NR) Based Nano-Sized Materials Using Sol-Gel Technique

    International Nuclear Information System (INIS)

    Dahlan Mohd; Mahathir Mohamed

    2011-01-01

    The objectives of this project are to prepare nano-sized natural rubber-based hybrid coating material by sol-gel technique; to explore the possibility of producing ENR-Si (epoxidized natural rubber-silica) cramer with toughening effects; and to use it in radiation curing of surface coating. Since early 1960s Malaysia has introduced various forms of value-added natural rubber such as Standard Malaysian Rubber (SMR), methylmethacrylate-grafted natural rubber (MG rubber), followed by liquid natural rubber and epoxidized natural rubber (ENR). Products such as liquid epoxidized natural rubber acrylate (LENRA) and thermoplastic natural rubber (TPNR) are still on-going research projects in Nuclear Malaysia. The former has strong possibility to be used as radiation-sensitive comparabilities in TPNR blends, besides its original purpose for example in radiation curing of surface coating. But earlier findings indicated that, to make it (as for surface coating) more effective, reinforcement system is needed to be introduced. Strong candidate is silica by sol-gel technique, since common reinforcement filler for example carbon black has drawbacks in this particular case. This technique was introduced in late 1960s to produce metal oxides such as silica and titanium oxides in solution. (author)

  20. Synthesis of lithium doped zinc oxide by sol gel

    International Nuclear Information System (INIS)

    Meziane, K; Elhichou, A; Elhamidi, A; Almaggoussi, A; CHHIBA, M

    2016-01-01

    Li-doped ZnO thin films were prepared by sol-gel method and deposed on glass substrate using spin coating technique. The effects of Li on structural and optical properties were investigated. The X-ray diffraction (XRD) analysis reveals that Li incorporation leads to the great improvement of the crystalline quality of ZnO thin films. Scanning electron microscopy (SEM) images showed that nanowires are aligned nearly perpendicular to the substrate plane and are affected significantly by Li incorporation. The optical transmission of the films was higher than 80% in the visible region. It is found that the optical gap and the refractive index remain practically constant. (paper)

  1. Preparation of nickel and Ni_3Sn nanoparticles via extension of conventional citric acid and ethylene diamine tetraacetic acid mediated sol–gel method

    International Nuclear Information System (INIS)

    Li, Pingyun; Deng, Guodong; Guo, Xiaode; Liu, Hongying; Jiang, Wei; Li, Fengsheng

    2016-01-01

    This work aims to extend the application field of sol–gel process from conventional oxides, carbides, sulfides to metallic nanocrystalline materials. Metallic ions were coordinated with chelating agents of citric acid (CA) and ethylene diamine tetraacetic acid (EDTA) in aqueous solution. Then the solutions were dried at 383 K, resulting in the formation of sol and gel. Heating treatments of dried gels were then carried out with protection of N_2 atmosphere. Ni and Ni_3Sn alloy nanoparticles were obtained by this sol–gel method in the range of 623–823 K. The as-prepared Ni and Ni_3Sn alloy nanoparticles have average grain sizes of 15 and 30 nm, and have face-centred-cubic (fcc) crystalline phase. Our results provide new insight into the application of conventional sol–gel method. - Graphical abstract: Sol–gel method is conventionally applied to prepare oxides, carbides, and sulfides. In this work, the application field of sol–gel method is extended to metallic nanoparticles. By using citric acid (CA) and ethylene diamine tetraacetic acid (EDTA) mediated sol–gel method, metallic Ni (a and c) and Ni_3Sn (b and d) alloy nanoparticles can be prepared when the heating treatments are performed under N_2 protecting atmosphere. The Ni and Ni_3Sn nanoparticles have face-centered-cubic (fcc) crystalline phase and ultrafine grain sizes. Diffraction peaks of (110) superstructure reflection plane of Ni_3Sn nanoparticles can also be observed in Figure b, which can be considered as direct evidence of formation of alloy crystalline phase by performing this sol–gel method. - Highlights: • Ni and Ni_3Sn alloy nanoparticles have been prepared by sol–gel processes. • Citric acid and ethylene diamine tetraacetic acid were applied as chelating agent. • Diffraction peak of superstructure reflection plane of Ni_3Sn was detected by XRD. • A novel strategy for preparation of alloy nanoparticles has been presented.

  2. Sol-gel based oxidation catalyst and coating system using same

    Science.gov (United States)

    Watkins, Anthony N. (Inventor); Leighty, Bradley D. (Inventor); Oglesby, Donald M. (Inventor); Patry, JoAnne L. (Inventor); Schryer, Jacqueline L. (Inventor)

    2010-01-01

    An oxidation catalyst system is formed by particles of an oxidation catalyst dispersed in a porous sol-gel binder. The oxidation catalyst system can be applied by brush or spray painting while the sol-gel binder is in its sol state.

  3. Processing and Characterization of Sol-Gel Cerium Oxide Microspheres

    Energy Technology Data Exchange (ETDEWEB)

    McClure, Zachary D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Padilla Cintron, Cristina [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-09-27

    Of interest to space exploration and power generation, Radioisotope Thermoelectric Generators (RTGs) can provide long-term power to remote electronic systems without the need for refueling or replacement. Plutonium-238 (Pu-238) remains one of the more promising materials for thermoelectric power generation due to its high power density, long half-life, and low gamma emissions. Traditional methods for processing Pu-238 include ball milling irregular precipitated powders before pressing and sintering into a dense pellet. The resulting submicron particulates of Pu-238 quickly accumulate and contaminate glove boxes. An alternative and dust-free method for Pu-238 processing is internal gelation via sol-gel techniques. Sol-gel methodology creates monodisperse and uniform microspheres that can be packed and pressed into a pellet. For this study cerium oxide microspheres were produced as a surrogate to Pu-238. The similar electronic orbitals between cerium and plutonium make cerium an ideal choice for non-radioactive work. Before the microspheres can be sintered and pressed they must be washed to remove the processing oil and any unreacted substituents. An investigation was performed on the washing step to find an appropriate wash solution that reduced waste and flammable risk. Cerium oxide microspheres were processed, washed, and characterized to determine the effectiveness of the new wash solution.

  4. Preparation of poly(acrylonitrile-butyl acrylate) gel electrolyte for lithium-ion batteries

    International Nuclear Information System (INIS)

    Tian Zheng; He Xiangming; Pu Weihua; Wan Chunrong; Jiang Changyin

    2006-01-01

    Poly(acrylonitrile-butyl acrylate) gel polymer electrolyte was prepared for lithium ion batteries. The preparation started with synthesis of poly(acrylonitrile-butyl acrylate) by radical emulsion polymerization, followed by phase inversion to produce microporous membrane. Then, the microporous gel polymer electrolytes (MGPEs) was prepared with the microporous membrane and LiPF 6 in ethylene carbonate/diethyl carbonate. The dry microporous membrane showed a fracture strength as high as 18.98 MPa. As-prepared gel polymer electrolytes presented ionic conductivity in excess of 3.0 x 10 -3 S cm -1 at ambient temperature and a decomposition voltage over 6.6 V. The results showed that the as-prepared gel polymer electrolytes were promising materials for Li-ion batteries

  5. Preparation of poly(acrylonitrile-butyl acrylate) gel electrolyte for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Tian Zheng [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); He Xiangming [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China)]. E-mail: hexm@tsinghua.edu.cn; Pu Weihua [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Wan Chunrong [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Jiang Changyin [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China)

    2006-10-25

    Poly(acrylonitrile-butyl acrylate) gel polymer electrolyte was prepared for lithium ion batteries. The preparation started with synthesis of poly(acrylonitrile-butyl acrylate) by radical emulsion polymerization, followed by phase inversion to produce microporous membrane. Then, the microporous gel polymer electrolytes (MGPEs) was prepared with the microporous membrane and LiPF{sub 6} in ethylene carbonate/diethyl carbonate. The dry microporous membrane showed a fracture strength as high as 18.98 MPa. As-prepared gel polymer electrolytes presented ionic conductivity in excess of 3.0 x 10{sup -3} S cm{sup -1} at ambient temperature and a decomposition voltage over 6.6 V. The results showed that the as-prepared gel polymer electrolytes were promising materials for Li-ion batteries.

  6. Synthesis and Characterization of Oxide Dispersion Strengthened Ferritic Steel via a Sol-Gel Route

    International Nuclear Information System (INIS)

    Sun Qinxing; Zhang Tao; Wang Xianping; Fang Qianfeng; Hu Jing; Liu Changsong

    2012-01-01

    Nanocrystalline oxide dispersion strengthened (ODS) ferritic steel powders with nominal composition of Fe-14Cr-3W-0.3Ti-0.4Y 2 O 3 are synthesized using sol-gel method and hydrogen reduction. At low reduction temperature the impurity phase of CrO is detected. At higher reduction temperature the impurity phase is Cr 2 O 3 which eventually disappears with increasing reduction time. A pure ODS ferritic steel phase is obtained after reducing the sol-gel resultant products at 1200°C for 3 h. The HRTEM and EDS mapping indicate that the Y 2 O 3 particles with a size of about 15 nm are homogenously dispersed in the alloy matrix. The bulk ODS ferritic steel samples prepared from such powders exhibit good mechanical performance with an ultimate tensile stress of 960 MPa.

  7. Thermal behavior of La2O3/Nio composite prepared by sol-gel method

    International Nuclear Information System (INIS)

    Sakallioglu, M.

    2005-01-01

    The La 2 O 3 /NiO composite was prepared by sol-gel method by using transition metal oxides (La 2 O 3 /NiO). The variation of specific heat capacity Cp with temperature for La2O3/NiO composite was investigated by DSC. The heat capacity curve was taken with a heating rate of 20 degrees/min between 0-100 degrees. The variation of specific heat capacity was found by PKI Muse Standard Analysis Program. The thermal stability of the La 2 O 3 /NiO composite was investigated by thermogravimetric analysis (TG) in air atmosphere at a heating rate of 20 degrees/min. The weight loss of La 2 O 3 /NiO composite was determined by the variation of temperature

  8. In Vitro and In Vivo Evaluation of Diclofenac Sodium Gel Prepared ...

    African Journals Online (AJOL)

    Purpose: To develop diclofenac sodium gel using high molecular weight hydroxypropyl methylcellulose (HPMC) and Carbopol 934P for topical and systemic delivery. Methods: Diclofenac sodium gel was prepared with HPMC K100M and Carbopol 934P as gelling agents. The formulations were examined for pH, ...

  9. Reproducibility of measurement of the environmental carbon-14 samples prepared by the gel suspension method

    International Nuclear Information System (INIS)

    Ohura, Hirotaka; Wakabayashi, Genichiro; Nakamura, Kouji; Okai, Tomio; Matoba, Masaru; Kakiuchi, Hideki; Momoshima, Noriyuki; Kawamura, Hidehisa.

    1997-01-01

    Simple liquid scintillation counting technique for the assay of 14 C in the environment was developed. This technique was done by using gel suspension method, in which sample preparation is very simple and requires no special equipments. The reproducibility of this technique was considered and it was shown that the gel suspension method had enough reproducibility to monitor the environmental 14 C. (author)

  10. Patterned transparent zinc oxide films produced by sol-gel embossing

    Energy Technology Data Exchange (ETDEWEB)

    Rao, J.; Koh, L.H.K.; Crean, G.M. [Tyndall National Institute, Lee Maltings, Prospect Row, Cork (Ireland); Department of Microelectronic Engineering, University College Cork, Cork (Ireland); O' Brien, S. [Tyndall National Institute, Lee Maltings, Prospect Row, Cork (Ireland); Winfield, R.J.

    2008-08-15

    A low cost zinc oxide embossing technique is reported as a method of fabricating structures relevant to a variety of applications. A zinc based sol-gel material was prepared from zinc acetate[Zn(C{sub 2}H{sub 3}O{sub 2}){sub 2}], monoethanolamine[H{sub 2}NC{sub 2}H{sub 4}OH] and isopropanol. The sol-gel was cast into a polydimethylsiloxane (PDMS) mould a track design, placed in contact with the substrate and dried under vacuum at 70 C for 3 hours. The formed track pattern was further densified to provide a stable conductor film that retained the embossed shape. An optimum Zn sol-gel content of 0.6 M was identified. The embossed films had a transparency of greater than 83% in the visible region. The optical bandgap energy was evaluated to be 3.306 eV. The influence of ZnO sol-gel film synthesis and embossing parameters on the microstructure, morphology and optical transparency of fabricated structures is described. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Catalytic oxidation of dichloromethane over sol-gel oxides supported Pd or Ni

    International Nuclear Information System (INIS)

    Martinez; Leidy Marcela; Montes, Consuelo

    2004-01-01

    Several supported Pd or Ni catalysts were synthesized by the sol-gel method using y-alumina, silica, sulfated zirconium and sulfated titanium as carriers. The resulting catalysts were characterized by XRD and nitrogen adsorption, and evaluated in the catalytic oxidation of dichloromethane. The effect of different parameters were determined, i.e. method of synthesis, temperature and the type of support. The durability of the best catalyst (0,5% Pd impregnated over sulfated titanium) was tested between 300 degrades Celsius and 350 degrades Celsius during 48 h. Under the conditions of this study, impregnated catalysts exhibited higher activity than those prepared by cogelation. Pd loaded catalysts showed higher conversion into CO 2 and HCl. Catalyst activity also increased with increasing temperature. Y-Alumina and sulfated titanium showed good activity but the formation of CO is favored instead of CO 2 . Therefore, bifunctional catalysts, i.e. containing metallic and acid sites appear to be required for the decomposition of methylene chloride into CO 2 and HCI

  12. Optical and electrochromic properties of sol-gel deposited Ti- doped vanadium oxide films

    International Nuclear Information System (INIS)

    Oezer, N.; Sabuncu, S.

    1997-01-01

    Because of the yellowish color, vanadium oxide films in the as deposited state is not as favorable as transparent coatings for most elector chromic devices. an interesting possibility to alter the yellowish colours is the doping with other non-absorbing metal oxides. Ti doped vanadium oxide films with various amounts of titanium were synthesized and investigated as transparent counter electrodes for electrochromic transmissive device application. Electrochromic titanium doped vanadium pentoxide (V sub 2 O 5) coatings were prepared by the sol-gel dip coating technique. The coating solutions were synthesized from vanadium tri(isopropoxide) precursors. X-ray diffraction (XRD) studies showed that the sol-gel deposited doped films heat treated at temperatures below 350 degree centigrade, were amorphous, whereas hose heat treated at higher temperatures were slight y crystalline. The optical and electrochemical properties of the Ti doped vanadium oxide films has been investigated in 0.1 m LiClO sub 4 propylene carbonate solution color changes by dropping were noted for all investigated films exhibits good electrochemical cycling (CV) measurements also showed that Ti doped V sub 2 O sub 5 films exhibits good electrochemical cycling reversibility, 'in situ' optical measurement revealed that those films exhibits good electrochemical cycling the spectra range 300 < lambda < 800 nm and change color between yellow and light green. The change in visible transmittance was 25 % for 5% Ti doped film. (author)

  13. Preparation Of Porous And Dense Bodies From Hydroxyapatite Powders Prepared Via Sol-Gel Technique

    International Nuclear Information System (INIS)

    Sopyan, Lis

    2001-01-01

    Hydroxyapatite (HA) ceramics is clinically proven and, thus, a reliable material for medical applications, that is, for use in dental and orthopedical surgery to fill cavities in bones. In this paper, we report a preliminary study on development of HA porous and dense materials manufactured using fine HA powders prepared via a sol-gel technique. In the preparation of HA porous bodies, slurries of the as-prepared powder were prepared with an adjusted loading ofHA, using Duramax of 0-3021 type as dispersant. After soaking cellulosic sponges into the slurry, the sponges were dried and then subjected to heat-treatment at 600 o C, followed by sintering at 1250 o C for I h. The apparent density of the porous bodies is 1.290 g/cm 3 , with a porosity of 59%. The sintering shrinkage is about 20% (in respect of dimension) and 44 % (in respect of volume). Morphological evaluation of the porous bodies showed that the samples contained macropores of 1-2 mm diameter and micropores of 1-2 μm diameter. The measurement of mechanical strength provided 1.31 ± 0.30 MPa. Subsequently, dense samples were prepared from the as-prepared powder. In this case, the powder was mixed with poly(vinyl alcohol) and distilled water to make a slurry. The mixture was mixed using Zirconia balls as the crusher for 2h. The suspension was then spray-dried, and well-dispersed powder was obtained. The powder was compressed uniaxially using cold pressing technique at 800 kglcm2 and the pellets obtained were sintered in air at : 250 o C for I h. The sintered dense bodies have apparent density of 2.855 g/cm 3 , with a 10% porosity. The flexural strength of the dense bodies measured on the specimens of riimension 2 mm x 2.5 mm gave rise to the considerable value of 57.7 MPa

  14. Acquisition of Preparative Gel Permeation Chromatography for Research and Education in Energy Conversion and Nanocomposites

    Science.gov (United States)

    2017-04-19

    AFRL-AFOSR-VA-TR-2017-0090 Acquisition of Preparative Gel Permeation Chromatography for Research and Education in Energy Conversion and...TITLE AND SUBTITLE Acquisition of Preparative Gel Permeation Chromatography for Research and Education in Energy Conversion and Nanocomposites 5a... research with education at all levels across a broad range of materials, and create important opportunities to expose and train undergraduates, women

  15. Synthesis and characterization of hollow α-Fe2O3 sub-micron spheres prepared by sol–gel

    International Nuclear Information System (INIS)

    León, Lizbet; Bustamante, Angel; Osorio, Ana; Olarte, G. S.; Santos Valladares, Luis De Los; Barnes, Crispin H. W.; Majima, Yutaka

    2011-01-01

    In this work we report the preparation of magnetic hematite hollow sub-micron spheres (α-Fe 2 O 3 ) by colloidal suspensions of ferric nitrate nine-hydrate (Fe(NO 3 ) 3 ·9H 2 O) particles in citric acid solution by following the sol–gel method. After the gel formation, the samples were annealed at different temperatures in an oxidizing atmosphere. Annealing at 180°C resulted in an amorphous phase, without iron oxide formation. Annealing at 250°C resulted in coexisting phases of hematite, maghemite and magnetite, whereas at 400°C, only hematite and maghemite were found. Pure hematite hollow sub-micron spheres with porous shells were formed after annealing at 600°C. The characterization was performed by X-ray diffraction (XRD), Mössbauer spectroscopy (MS) and scanning electron microscopy (SEM).

  16. Preparation and characterization of vanadium oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Monfort, O.; Plesch, G. [Comenius University of Bratislava, Faculty of Natural Sciences, Department of Inorganic Chemistry, 84215 Bratislava (Slovakia); Roch, T. [Comenius University of Bratislava, Faculty of Mathematics Physics and Informatics, Department of Experimental Physics, 84248 Bratislava (Slovakia)

    2013-04-16

    The thermotropic VO{sub 2} films have many applications, since they exhibit semiconductor-conductor switching properties at temperature around 70 grad C. Vanadium oxide thin films were prepared via sol-gel method. Spin coater was used to depose these films on Si/SiO{sub 2} and lime glass substrates. Thin films of V{sub 2}O{sub 5} can be reduced to metastable VO{sub 2} thin films at the temperature of 450 grad C under the pressure of 10{sup -2} Pa. These films are then converted to thermotropic VO{sub 2} at 700 grad C in argon under normal pressure. (authors)

  17. Preparation of gold nanoparticles-agarose gel composite and its application in SERS detection

    Science.gov (United States)

    Ma, Xiaoyuan; Xia, Yu; Ni, Lili; Song, Liangjing; Wang, Zhouping

    2014-03-01

    Agarose gel/gold nanoparticles hybrid was prepared by adding gold nanoparticles to preformed agarose gel. Nanocomposite structures and properties were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and UV-Vis-NIR absorption spectroscopy. Based on the swelling-contraction characteristics of agarose gel and the adjustable localized surface plasmon resonance (LSPR) of the gold nanoparticles, the nanocomposites were used as surface enhanced Raman scattering (SERS) substrate to detect the Raman signal molecules (NBA, MBA, 1NAT). Results revealed that the porous structure of the agarose gel provided a good carrier for the enrichment of the gold nanoparticles. The gold nanoparticles dynamic hot-spot effect arising from the agarose gel contraction loss of water in the air greatly enhanced the Raman signal. Furthermore, the gel could be cleaned with washing solution and recycling could be achieved for Raman detection.

  18. Lithium ceramics: sol-gel preparation and tritium release; Ceramiques lithiees: elaboration sol-gel et relachement du tritium

    Energy Technology Data Exchange (ETDEWEB)

    Renoult, O

    1994-04-01

    Ceramics based on lithium aluminate (LiA1O{sub 2}), lithium zirconate (Li{sub 2}ZrO{sub 3}) and lithium titanate (Li{sub 2}TiO{sub 3}) are candidates as tritium breeder blanket materials for forthcoming nuclear fusion reactors. Lithium silico-aluminate Li{sub 4+x}A1{sub 4-3x}Si{sub 2x}O{sub 8} (0 {<=} x {<=} 0,25) powders were synthetized from alkoxyde-hydroxyde sol-gel route. By direct sintering at 850-1100 deg C (without prior calcination), ceramics with controlled stoichiometry and homogenous microstructure were obtained. We have also prepared, using a comparable method, Li{sub 2}Zr{sub 1-x}Ti{sub x}O{sub 3} (x = 0, x = 0,1 et x = 1) materials. All these ceramics, with different microstructures and compositions, have been tested in out-of-reactor experiments. Concerning lithium aluminate microporous ceramics, the silicon substitution leads to a significant improvement of the tritrium release. Classical models taking into account independent surface mechanisms are not able to describe correctly the observed tritium release kinetics. We show, using a simple model, that the release kinetics is in fact limited by an intergranular diffusion followed by a desorption. The delay in tritium release, which occurs when the ceramic compacity increases, is explained in terms of an enhancement of the ionic T{sup +} diffusion path length. The energy required for desorption includes a leading term independent of hydrogen contained in the sweep gas. This term is attributed to the limiting recombination step of T{sup +} in molecular species HTO. For similar microstructures, the facility of tritium release for the different studied materials is explained by three properties: the crystal structure of the ceramic, the acidity of oxides and finally the presence of electronic non-stoichiometric defects. (author). 89 refs., 50 figs., 2 tabs., 1 annexe.

  19. Sol–gel preparation of selected lanthanide aluminium garnets

    Czech Academy of Sciences Publication Activity Database

    Dubnikova, N.; Garskaite, E.; Pinkas, J.; Bezdička, Petr; Beganskiene, A.; Kareiva, A.

    2010-01-01

    Roč. 55, č. 2 (2010), s. 213-219 ISSN 0928-0707 Institutional research plan: CEZ:AV0Z40320502 Keywords : lanthanide aluminium garnets * sol-gel processing Subject RIV: CA - Inorganic Chemistry Impact factor: 1.525, year: 2010

  20. Lithium containing MgAl mixed oxides obtained from sol-gel hydrotalcite for transesterification

    Directory of Open Access Journals (Sweden)

    Renata A. B. Lima-Corrêa

    Full Text Available Abstract The innumerous advantages of heterogeneous catalysts employed in biodiesel production have stimulated the search for a solid catalyst capable of replacing the industrially used homogeneous catalysts. This paper investigates the effect of the sol-gel method in the catalytic activity and stability of Li-MgAl mixed oxides prepared by the “in situ” lithium addition to a MgAl hydrotalcite. The analyses based on N2 physisorption, thermogravimetric analysis, X-ray diffractometry, scanning electron microscopy and temperature-programmed desorption of CO2 were carried out to elucidate the properties of the catalysts. Considerable differences in the physico-chemical properties of the catalysts were observed with the Li addition. Li reduced the surface area and increased the crystallite size of the oxides. Furthermore, Li-MgAl mixed oxides prepared by the calcination of the sol-gel MgAl hydrotalcites presented substantial morphological differences when compared to the same oxides obtained by heat treatment of hydrotalcites synthesized via the conventional co-precipitation route. Furthermore, Li increased the number and strength of the base sites which resulted in the increase of the oxide reactivities towards the transesterification reaction between methyl acetate and ethanol. The activity was dependent on the Li loading on the catalysts. The catalyst containing only 5 wt.% Li turned out to be highly active (( 85% conversion at 50°C, ethanol/methyl acetate molar ratio = 6/1, 4 wt.% of catalyst and 30 min of reaction. Stability tests showed that the Li-MgAl catalysts lose activity after 3 reuse cycles.

  1. Gel stabilization in chelate sol-gel preparation of Bi-2223 superconductors

    Czech Academy of Sciences Publication Activity Database

    Rubešová, K.; Jakeš, V.; Hlásek, T.; Vašek, Petr; Matějka, P.

    2012-01-01

    Roč. 73, č. 3 (2012), s. 448-453 ISSN 0022-3697 Institutional research plan: CEZ:AV0Z10100521 Keywords : superconductors * sol-gel growth * infrared spectroscopy * thermogravimetric analysis (TGA) * X-ray diffraction Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.527, year: 2012

  2. Au Nanoparticle Sub-Monolayers Sandwiched between Sol-Gel Oxide Thin Films

    Science.gov (United States)

    Della Gaspera, Enrico; Menin, Enrico; Sada, Cinzia

    2018-01-01

    Sub-monolayers of monodisperse Au colloids with different surface coverage have been embedded in between two different metal oxide thin films, combining sol-gel depositions and proper substrates functionalization processes. The synthetized films were TiO2, ZnO, and NiO. X-ray diffraction shows the crystallinity of all the oxides and verifies the nominal surface coverage of Au colloids. The surface plasmon resonance (SPR) of the metal nanoparticles is affected by both bottom and top oxides: in fact, the SPR peak of Au that is sandwiched between two different oxides is centered between the SPR frequencies of Au sub-monolayers covered with only one oxide, suggesting that Au colloids effectively lay in between the two oxide layers. The desired organization of Au nanoparticles and the morphological structure of the prepared multi-layered structures has been confirmed by Rutherford backscattering spectrometry (RBS), Secondary Ion Mass Spectrometry (SIMS), and Scanning Electron Microscopy (SEM) analyses that show a high quality sandwich structure. The multi-layered structures have been also tested as optical gas sensors. PMID:29538338

  3. SEM studies of the structure of the gels prepared from untreated and radiation modified potato starch

    International Nuclear Information System (INIS)

    Cieśla, Krystyna; Sartowska, Bożena; Królak, Edward

    2015-01-01

    Potato starch was irradiated with a 60 Co gamma rays using doses of 5, 10, 20 and 30 kGy. Gels containing ca. 9.1% of starch were prepared by heating the starch suspensions in the heating chamber stabilized at 100 °C. Four procedures were applied for preparation of the samples in regard to SEM studies and the ability to observe the radiation effect by SEM was assessed for each method. Differences were observed between the SEM images recorded for the non-irradiated samples prepared using all the methods, and those irradiated. Images of the non-irradiated gels indicate generally a honey-comb structure, while smooth areas but with oriented fractures has appeared after irradiation. Modification of gel structure corresponds to the applied dose. The results were related to the process of gel formation (as observed by means of the hot stage microscope) to decrease in swelling power of the irradiated starch and to decreased viscosity of the resulting gels. It can be concluded that the differences in structural properties of gels shown by SEM result probably due to the better homogenization of the gels formed after radiation induced degradation. - Highlights: • Four procedures of the preservation of starch gels for SEM studies were applied. • The ability to observe the radiation effect by SEM was assessed for each method. • Dose dependent changes in the gel structure were discovered. • It was related to decrease in the swelling power and decreased viscosity of the gels. • A hot-stage microscope was applied in order to follow the gelatinization process

  4. Sol–gel synthesis of nanostructured indium tin oxide with controlled morphology and porosity

    Energy Technology Data Exchange (ETDEWEB)

    Kőrösi, László, E-mail: ltkorosi@gmail.com [Department of Biotechnology, Nanophage Therapy Center, Enviroinvest Corporation, Kertváros u. 2, H-7632 Pécs (Hungary); Scarpellini, Alice [Department of Nanochemistry, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy); Petrik, Péter [Institute for Technical Physics and Materials Science, Konkoly-Thege út 29-33, H-1121 Budapest (Hungary); Papp, Szilvia [Department of Biotechnology, Nanophage Therapy Center, Enviroinvest Corporation, Kertváros u. 2, H-7632 Pécs (Hungary); Dékány, Imre [MTA-SZTE Supramolecular and Nanostructured Materials Research Group, University of Szeged, Dóm tér 8, H-6720 Szeged (Hungary)

    2014-11-30

    Graphical abstract: - Highlights: • Nanocrystalline ITO thin films and powders were prepared by a sol–gel method. • The nature of the compounds used for hydrolysis plays a key role in the morphology. • Hydrolysis of In{sup 3+}/Sn{sup 4+} with EA led to a rod-like morphology. • Monodisperse spherical ITO nanoparticles were obtained on the use of AC. • ITO{sub E}A was highly porous, while ITO{sub A}C contained densely packed nanocrystals. - Abstract: Nanostructured indium tin oxide (ITO) powders and thin films differing in morphology and porosity were prepared by a sol–gel method. In{sup 3+} and Sn{sup 4+} were hydrolyzed in aqueous medium through the use of ethanolamine (EA) or sodium acetate (AC). X-ray diffraction measurements demonstrated that both EA and AC furnished indium tin hydroxide, which became nanocrystalline after aging for one day. The indium tin hydroxide samples calcined at 550 °C afforded ITO with a cubic crystal structure, but the morphology differed significantly, depending on the agent used for hydrolysis. Electron microscopy revealed the formation of round monodisperse nanoparticles when AC was used, whereas the application of EA led to rod-like ITO nanoparticles. Both types of nanoparticles were suitable for the preparation of transparent and conductive ITO thin films. The influence of the morphology and porosity on the optical properties is discussed.

  5. Electrical stability of Al-doped ZnO transparent electrode prepared by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Tabassum, Samia, E-mail: shawon14@gmail.com; Yamasue, Eiji; Okumura, Hideyuki; Ishihara, Keiichi N.

    2016-07-30

    Highlights: • Al-doped ZnO thin film was deposited by sol-gel method in different annealing temperature and duration. • We examined the environmental stability in ambient and damp heat condition. • We investigated chemical state of thin film. • Better stability was observed in the film annealed at high temperature (600 °C) along with longer duration (120 min). • An ultrathin aluminum oxide layer formation was predicted by XPS measurement which protects further oxidation and improves stability. - Abstract: Al-doped zinc oxide (AZO) thin films have been considered as a promising alternative to tin doped indium oxide (ITO), which is currently used in various optoelectronic applications. However, the environmental stability of AZO film is not satisfactory, in that the resistivity is significantly increases in air. Here, we investigate the resistivity stability of AZO thin films prepared by sol-gel method using various annealing temperatures and durations. The degradation of resistivity property was observed for AZO films stored in ambient or damp heat environment, where the degradation rate was influenced by annealing temperature. A significant improvement of electrical stability was attained in AZO films that were prepared at high annealing temperature. The films, which showed the highest and the lowest increasing rate of resistivity, were further characterized in detail to shed light on the possible mechanisms explaining the improved stability through crystallinity, surface morphology and elemental state of the thin film.

  6. Electrical stability of Al-doped ZnO transparent electrode prepared by sol-gel method

    International Nuclear Information System (INIS)

    Tabassum, Samia; Yamasue, Eiji; Okumura, Hideyuki; Ishihara, Keiichi N.

    2016-01-01

    Highlights: • Al-doped ZnO thin film was deposited by sol-gel method in different annealing temperature and duration. • We examined the environmental stability in ambient and damp heat condition. • We investigated chemical state of thin film. • Better stability was observed in the film annealed at high temperature (600 °C) along with longer duration (120 min). • An ultrathin aluminum oxide layer formation was predicted by XPS measurement which protects further oxidation and improves stability. - Abstract: Al-doped zinc oxide (AZO) thin films have been considered as a promising alternative to tin doped indium oxide (ITO), which is currently used in various optoelectronic applications. However, the environmental stability of AZO film is not satisfactory, in that the resistivity is significantly increases in air. Here, we investigate the resistivity stability of AZO thin films prepared by sol-gel method using various annealing temperatures and durations. The degradation of resistivity property was observed for AZO films stored in ambient or damp heat environment, where the degradation rate was influenced by annealing temperature. A significant improvement of electrical stability was attained in AZO films that were prepared at high annealing temperature. The films, which showed the highest and the lowest increasing rate of resistivity, were further characterized in detail to shed light on the possible mechanisms explaining the improved stability through crystallinity, surface morphology and elemental state of the thin film.

  7. Preparation and characterization of PAN–KI complexed gel polymer ...

    Indian Academy of Sciences (India)

    The conductivity-temperature dependence of these polymer electrolyte films obeys Arrhenius behaviour with activa- ... oxide (PEO), polyvinyl alcohol, polyvinyl pyrrolidone (PVP) ... chemical, flame resistance and electrochemical stability.

  8. Thermal stability of octadecylsilane hybrid silicas prepared by grafting and sol-gel methods

    International Nuclear Information System (INIS)

    Brambilla, Rodrigo; Santos, Joao H.Z. dos; Miranda, Marcia S.L.; Frost, Ray L.

    2008-01-01

    Hybrid silicas bearing octadecylsilane groups were prepared by grafting and sol-gel (SG) methods. The effect of the preparative route on the thermal stability was evaluated by means of thermal gravimetric analysis (TGA), infrared emission spectroscopy (IRES) and, complementary, by 13 C solid-state nuclear magnetic resonance ( 13 C NMR) and matrix assisted laser deionization time of flight mass spectroscopy (MALDI-TOF-MS). Silicas prepared by the grafting route seem to be slightly more stable than those produced by the sol-gel method. This behavior seems to be associated to the preparative route, since grafting affords a liquid-like conformation, while in the case of sol-gel a highly organized crystalline chain conformation was observed

  9. Preparation of durable insecticide cotton fabrics through sol–gel treatment with permethrin

    OpenAIRE

    Ardanuy Raso, Mònica; Faccini, Mirko; Amantia, David; Aubouy, Laurent; Borja, Guadalupe

    2014-01-01

    This paper presents the development of an industrially viable procedure for the fabrication of durable insecticide textiles based on the sol–gel technique. Permethrin was incorporated on cotton fabrics by a silicon oxide nanocoating applied by conventional padding followed by curing. The effect of the sol–gel process parameters, such as silica solid content and the permethrin/tetraethyl orthosilicate (TEOS) ratio on the insecticide activity and on the textile properties of the resulting fabri...

  10. Effect of ammonium hydroxide on preparation process of YBa2Cu3O7-x superconductor by sol gel method

    Directory of Open Access Journals (Sweden)

    H Arabi

    2006-09-01

    Full Text Available  In this paper the effect of ammonium hydroxide addition to the solution of metallic oxide on sol gel preparation process of YBCO is studied with differential thermal analysis, thermal graviometry and X-ray diffraction. Two samples with and without ammonium hydroxide. Ammonium hydroxide prevents both barium nitrate precipitate during the gel preparation and also unwanted reaction as well as increasing homogeneous product. After drying the gel, the samples heated up to 1050°C in DTA apparatus in order to find more accurate the type and the temperature of reaction during the preparation process. After the initial reactions in the samples, Y2Cu2O5 and 123 phases are created in the range of 780-840°C and then the 123 phase is strengthened at 900-950°C. As shown in X-ray data, 123 was the only phase after this range. In addition ammonium hydroxide support and increase the creation of 123 phase at lower temperature.

  11. Preparation of UO2 dense spherical particles by sol-gel technique

    International Nuclear Information System (INIS)

    Urbanek, V.; Dolezal, J.

    1977-01-01

    The results of the basic research and development of processes of preparation of dense UO 2 spherical particles by sol-gel technique are presented. Attention was paid to the study of chemistry of internal gelation step in the uranylnitrate-urea-hexamethylentetramine system. The existence regions of several stable gels with different properties were established in connection with variable ratio of basic gel's components and the appropriate ''Phase diagrams'' were drawn. From these diagrams, two of the most interesting types of uranyl gels were chosen for the subsequent thermal processing which included drying, reduction and sintering. The detailed studies of each step of the whole process enabled preparation of UO 2 dense spheres with well defined microstructure

  12. Preparation and characterization of conductive and transparent ruthenium dioxide sol-gel films.

    Science.gov (United States)

    Allhusen, John S; Conboy, John C

    2013-11-27

    RuO2 conductive thin films were synthesized using the sol-gel method and deposited onto transparent insulating substrates. The optical transmission, film thickness, surface morphology and composition, resistivity, and spectroelectrochemical performance have been characterized. The optical transmission values of these films ranged from 70 to 89% in the visible region and from 56 to 88% in the infrared region. Resistivity values of the RuO2 sol-gel films varied from 1.02 × 10(-3) to 1.13 Ω cm and are highly dependent on the initial solution concentration of RuO2 in the sol-gel. The RuO2 sol-gel films were used as electrodes for the electrochemical oxidation and reduction of ferrocenemethanol. The electrochemical behavior of our novel RuO2 sol-gel films was compared to that of a standard platinum disk electrode and showed no appreciable differences in the half-wave potential (E1/2). The mechanical and chemical stability of the coatings was tested by physical abrasion and exposure to highly acidic, oxidizing Piranha solution. Repeated exposure to these extreme conditions did not result in any appreciable decline in electrochemical performance. Finally, the use of the novel RuO2 sol-gel conductive and transparent films was demonstrated in a spectroelectrochemistry experiment in which the oxidation and reduction of ferrocenemethanol was monitored via UV-vis spectroscopy as the applied potential was cycled.

  13. Comparison of non-electrophoresis grade with electrophoresis grade BIS in NIPAM polymer gel preparation

    Science.gov (United States)

    Khodadadi, Roghayeh; Khajeali, Azim; Farajollahi, Ali Reza; Hajalioghli, Parisa; Raeisi, Noorallah

    2015-01-01

    Introduction:The main objective of this study was to investigate the possibility of replacing electrophoresis cross-linker with non-electrophoresis N, N′-methylenebisacrylamide (BIS) in N-isopropyl acrylamide (NIPAM) polymer gel and its possible effect on dose response. Methods: NIPAM polymer gel was prepared from non-electrophoresis grade BIS and the relaxation rate (R2) was measured by MR imaging after exposing the gel to gamma radiation from Co-60 source. To compare the response of this gel with the one that contains electrophoresis grade BIS, two sets of NIPAM gel were prepared using electrophoresis and non-electrophoresis BIS and irradiated to different gamma doses. Results: It was found that the dose–response of NIPAM gel made from the non-electrophoresis grade BIS is coincident with that of electrophoresis grade BIS. Conclusion:Taken all, it can be concluded that the non-electrophoresis grade BIS not only is a suitable alternative for the electrophoresis grade BIS but also reduces the cost of gel due to its lower price. PMID:26457250

  14. Recovery of Filtered Graphene Oxide Residue Using Elastic Gel Packed in a Column by Cross Flow

    Directory of Open Access Journals (Sweden)

    Yuji Takaoka

    2018-04-01

    Full Text Available To recover the filtered residues on a gel layer in a column, the method using the elasticity of the gel layer and flowing water in a cross-flow manner is proposed. Polymerized spherical gel (40 μm was packed in a column to a set height of 0.7 cm. The suspensions of graphene oxide at various sizes and shapes were injected on the top of the gel layer and then water was flowed at a flow rate of 1000 mL·h−1 until 0.10 MPa. By releasing the applied pressure, the elastic gel layer rose up, and the filtered graphene oxide also rose above the layer. This rise of the gel layer is due to the difference of pressure between the gel layer, including the filtered graphene oxide, and the open bottom of the column, using the flow of water. The cross flow of water through the column carried away the larger-sized filtered graphene oxide floating above the gel layer. The elasticity of the gel layer and cross flow through the column has the potential to recover the filtered particles.

  15. Sol-Gel Synthesis and Characterization of Cubic Bismuth Zinc Niobium Oxide Nanopowders

    Directory of Open Access Journals (Sweden)

    Ganchimeg Perenlei

    2014-01-01

    Full Text Available Bismuth zinc niobium oxide (BZN was successfully synthesized by a diol-based sol-gel reaction utilizing metal acetate and alkoxide precursors. Thermal analysis of a liquid suspension of precursors suggests that the majority of organic precursors decompose at temperatures up to 150°C, and organic free powders form above 350°C. The experimental results indicate that a homogeneous gel is obtained at about 200°C and then converts to a mixture of intermediate oxides at 350–400°C. Finally, single-phased BZN powders are obtained between 500 and 900°C. The degree of chemical homogeneity as determined by X-ray diffraction and EDS mapping is consistent throughout the samples. Elemental analysis indicates that the atomic ratio of metals closely matches a Bi1.5ZnNb1.5O7 composition. Crystallite sizes of the BZN powders calculated from the Scherrer equation are about 33–98 nm for the samples prepared at 500–700°C, respectively. The particle and crystallite sizes increase with increased sintering temperature. The estimated band gap of the BZN nanopowders from optical analysis is about 2.60–2.75 eV at 500-600°C. The observed phase formations and measured results in this study were compared with those of previous reports.

  16. Preparation and Characterization of Hydrous Zirconium Oxide Formed by Homogeneous Precipitation

    Directory of Open Access Journals (Sweden)

    Silva G.L.J.P. da

    2002-01-01

    Full Text Available This paper reports on the preparation, characterization and study of the ion exchange behavior of hydrous zirconium oxides formed by homogeneous precipitation from zirconium oxychloride. The precipitants used were obtained by thermal decomposition of urea, sodium nitrite or ammonium carbonate. Seven compounds were prepared and characterized by thermal analysis, X-ray diffractometry and by surface area measurements. Amorphous forms were obtained in each case, a result that agrees with those obtained by conventional gel precipitation methodology. All these materials present surface area values of >148 m².g-1, determined after heat treatment at 50 °C. The ion exchange behavior of each hydrous zirconium oxide prepared was studied using K+ as the exchanged species and the results compared with those obtained for hydrous zirconium oxide originally precipitated by the sol gel method.

  17. Sol gel synthesis for preparation of yttrium aluminium garnet

    NARCIS (Netherlands)

    Vrolijk, J.W.G.A.; Willems, J.W.M.M.; Metselaar, R.; With, de G.; Terpstra, R.A.; Metselaar, R.

    1989-01-01

    Sol-gel—synthesis for preparation of pure yttrium aluminium garnet powder with small grain size is subject of this ongoing study. Starting materials were sulfates and chlorides of yttrium and aluminium. To obtain pure YAG (Y3A1SO1Z) pH during hydrolysis as well as temperature during calcination and

  18. Microstructure, optical, and electrochromic properties of sol-gel nanoporous tungsten oxide films

    Science.gov (United States)

    Djaoued, Yahia; Ashrit, P. V.; Badilescu, S.; Bruning, R.

    2003-08-01

    Porous tungsten oxide films have been prepared by a nonhydrolitic sol-gel method using poly(ethylene glycol) (PEG) as a structure directing agent. The method entails the hydrolysis of an ethanolic solution of tungsten ethoxide (formed by the reaction of WCl6 with ethanol) followed by condensation and polymerization at the PEG-tungsten oxide oligometers interface. A highly porous WO3 framework was obtained after PEG was burned off by calcination at a relativley low temperature. AFM images of the films treated thermally show an ordered material rather than microscopic particulates. Both fibrilar nanostructures and striped phase can be obtained via this approach, depending on the concentration of PEG in the coating solution. XRD data from the fibrils indicate that they are crystalline with very small crystals, whereas the striped phases obtained with 20% PEG correspond to two crystalline phases, one, the stoichiometric WO3 and the other one an oxygen deficient phase, containing larger crystals (~28 nm). The results show that PEG promotes the formation of oxygen deficient phases and delays crystallization. Compared to WO3 with no PEG, the optical and electrochromic properties of the macroporous tungsten oxide films appear to be significantly improved. The formation of organized nanostructures is tentatively accounted for by the strong hydrogen bonding interactions between PEG and the tungsten oxide oligomers.

  19. Preparation of SDC electrolyte thin films on dense and porous substrates by modified sol-gel route

    International Nuclear Information System (INIS)

    Lin Hongfei; Ding, Changsheng; Sato, Kazuhisa; Tsutai, Yoshifumi; Ohtaki, Hiromichi; Iguchi, Mabito; Wada, Chiharu; Hashida, Toshiyuki

    2008-01-01

    Nanocrystalline fluorite type samarium doped ceria (SDC) electrolyte thin film for intermediate temperature-solid oxide fuel cells (IT-SOFCs) application were prepared on the dense and porous substrates at low temperatures of 573-1373 K using a novel citrate sol-gel route combined with a sol suspension spray coating technique. Thermogravimetric analysis showed that the decomposition of the citrate gel film and the initial crystallization of the SDC occurred at a low temperature of about 590 K. XRD examination revealed that the annealing of the green film at temperatures of 573-1373 K provided cubic nanocrystalline SDC phase. The crystallite sizes were in the range of 9-19 nm. Microscopic observations indicated that the derived film was homogeneous, dense and crack-free without pinholes. The desired thickness for preparation of thin electrolyte films from hundreds of nm to several μm should be controllable and feasible by repeating the simple and inexpensive citrate sol-gel spray coating process

  20. comparative study between different oxidizing agents to prepare radioiodinated alpha fetoprotein (AFP)

    International Nuclear Information System (INIS)

    El-Kolaly, M.T.; Ragab, M.T.; El-Mohty, A.A.; Sallam, K.M.; Arief, M.H.

    2004-01-01

    the aim of the present study was designed to prepare four different preparation of radioiodinated alpha fetoprotein ( 125 I-Afp) using different oxidizing agents. the oxidizing agents were chloramine-T (Ch-T), lodogen (1,3,4 , 6-tetrachloro 3 α ,6α diphenyl glycoluril ), N-bromosuccinimide (NBS) and lactoperoxidase (LPS). the product was purified by gel filtration using sephadex G-25. then the tracers obtained were tested by radioimmunoassay (RIA) technique. different affecting factors were extensively studied including reaction time, reaction volume, oxidizing agent content and Ph of reaction. it was found that the Ch-T method is the best one

  1. Preparation of Diatomite Supported Nano Zinc Oxide Composite Photocatalytic Material and Study on its Formaldehyde Degradation

    Science.gov (United States)

    Xiao, Liguang; Pang, Bo

    2017-09-01

    This experiment used zinc nitrate as precursor, ethanol as solvent and polyethylene glycol as dispersant, diatomite as carrier, diatomite loaded nano Zinc Oxide was prepared by sol-gel method, in addition, the formaldehyde degradation was studied by two kinds of experimental methods: preparation and loading, preparation and post loading, The samples were characterized by SEM, XRD, BET and IR. Experimental results showed that: Diatomite based nano Zinc Oxide had a continuous adsorption and degradation of formaldehyde, formaldehyde gas with initial concentration was 0.7mg/m3, after 36h degradation, the concentration reached 0.238mg/m3, the degradation rate reached to 66%.

  2. Impact of temperature on zinc oxide particle size by using sol-gel process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Keanchuan, E-mail: lee.kc@petronas.com.my; Ching, Dennis Ling Chuan, E-mail: dennis.ling@petronas.com.my [Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, 31750 Tronoh, Perak (Malaysia); Saipolbahri, Zulhilmi Akmal bin, E-mail: zulhilmiakmal@gmail.com [Geoscience and Petroleum Engineering Department, Universiti Teknologi PETRONAS, 31750 Tronoh, Perak (Malaysia); Guan, Beh Hoe, E-mail: beh.hoeguan@petronas.com.my, E-mail: hassan.soleimani@petronas.com.my; Soleimani, Hassan, E-mail: beh.hoeguan@petronas.com.my, E-mail: hassan.soleimani@petronas.com.my

    2014-10-24

    Zinc oxide (ZnO) nanoparticles were prepared and synthesized via sol-gel method, by using citric acid as a precursor. The impact of annealing on the particle size was investigated. Based on the results from the Thermogravimetric Analysis (TGA), three different annealing temperature which is 500, 600 and 700 °C were chosen followed by the characterization of the ZnO nanoparticle by using Powder X-Ray Diffraction (PXRD), Transmission Electron Microscopy (TEM) and Field Emission Scanning Electron Microscopy (FESEM). Results showed that the crystallite size estimated from PXRD increased with the annealing temperature which was hexagonal structure for ZnO. TEM further revealed the same tendency which the Zn NPs size also increased with the annealing temperature.

  3. Impact of temperature on zinc oxide particle size by using sol-gel process

    International Nuclear Information System (INIS)

    Lee, Keanchuan; Ching, Dennis Ling Chuan; Saipolbahri, Zulhilmi Akmal bin; Guan, Beh Hoe; Soleimani, Hassan

    2014-01-01

    Zinc oxide (ZnO) nanoparticles were prepared and synthesized via sol-gel method, by using citric acid as a precursor. The impact of annealing on the particle size was investigated. Based on the results from the Thermogravimetric Analysis (TGA), three different annealing temperature which is 500, 600 and 700 °C were chosen followed by the characterization of the ZnO nanoparticle by using Powder X-Ray Diffraction (PXRD), Transmission Electron Microscopy (TEM) and Field Emission Scanning Electron Microscopy (FESEM). Results showed that the crystallite size estimated from PXRD increased with the annealing temperature which was hexagonal structure for ZnO. TEM further revealed the same tendency which the Zn NPs size also increased with the annealing temperature

  4. Preparation and characterization of core-shell electrodes for application in gel electrolyte-based dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Avellaneda, Cesar O.; Goncalves, Agnaldo D.; Benedetti, Joao E.; Nogueira, Ana F.

    2010-01-01

    Core-shell electrodes based on TiO 2 covered with different oxides were prepared and characterized. These electrodes were applied in gel electrolyte-based dye-sensitized solar cells (DSSC). The TiO 2 electrodes were prepared from TiO 2 powder (P25 Degussa) and coated with thin layers of Al 2 O 3 , MgO, Nb 2 O 5 , and SrTiO 3 prepared by the sol-gel method. The core-shell electrodes were characterized by X-ray diffraction, scanning electron microscopy and atomic force microscopy measurements. J-V curves in the dark and under standard AM 1.5 conditions and photovoltage decay measurements under open-circuit conditions were carried out in order to evaluate the influence of the oxide layer on the charge recombination dynamics and on the device's performance. The results indicated an improvement in the conversion efficiency as a result of an increase in the open circuit voltage. The photovoltage decay curves under open-circuit conditions showed that the core-shell electrodes provide longer electron lifetime values compared to uncoated TiO 2 electrodes, corroborating with a minimization in the recombination losses at the nanoparticle surface/electrolyte interface. This is the first time that a study has been applied to DSSC based on gel polymer electrolyte. The optimum performance was achieved by solar cells based on TiO 2 /MgO core-shell electrodes: fill factor of ∼0.60, short-circuit current density J sc of 12 mA cm -2 , open-circuit voltage V oc of 0.78 V and overall energy conversion efficiency of ∼5% (under illumination of 100 mW cm -2 ).

  5. Assessment of a gel-type chelating preparation containing 1-hydroxyethylidene-1, 1-bisphosphonate.

    Science.gov (United States)

    Girard, S; Paqué, F; Badertscher, M; Sener, B; Zehnder, M

    2005-11-01

    To test an aqueous gel containing 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP) regarding its interactions with sodium hypochlorite, its calcium binding capacity, and its potential in preventing the formation of a smear layer when used in conjunction with rotary root canal preparation. The experimental aqueous gel consisted of (w/v) 2% alginate, 3% aerosil, 10% Tween 80 and 18% HEBP. Interactions of gel components with hypochlorite were assessed using iodometric titration and monochromatic ultraviolet spectrometry. Two commercial paste-type chelators containing ethylenediaminetetraacetic acid (EDTA) and peroxide (RC-Prep and Glyde) served as controls. Calcium-binding capacities were measured in mixtures with a Ca2+ standard solution buffered at pH 10 using a calcium-selective measuring chain. Finally, root canals of 16 extracted single-rooted premolars per group were instrumented using ProFile instruments dipped in the experimental gel, RC-Prep, or nothing. Additionally, canals were rinsed with 10 mL of a 1% NaOCl solution during/after preparation. Smear scores in instrumented teeth were monitored using scanning electron microscopy. None of the experimental gel components showed short-term interactions with hypochlorite, whilst EDTA, peroxide, RC-Prep and Glyde immediately reduced the hypochlorite in solution. The experimental gel chelated 30 mg Ca2+ g-1, compared with 16 mg Ca2+ g-1 and 11 mg Ca2+ g-1 chelated by RC-Prep and Glyde respectively. Smear scores obtained with the experimental gel were significantly (P<0.05) lower than with RC-Prep in coronal and middle root thirds, whilst no differences were observed in apical root thirds. Under the conditions of this study, an HEBP gel appeared advantageous over currently available products.

  6. Silica-gel modified with zirconium oxide as a novel 99Mo adsorbent 99mTc generators

    International Nuclear Information System (INIS)

    Salehi, H.; Mollarazi, E.; Abbasi, H.

    2010-01-01

    A new 99 Mo adsorbent has been prepared with modified silica gel with zirconium oxide (SiO 2 /ZrO 2 :Na 2 MoO 4 ) and used in technetium-99m generator. The adsorption behaviors of 99 Mo in the form of molybdate and 99m Tc in the form of pertechnetate on the new adsorbent was investigated showed that the adsorption capacity of molybdate on this generator was considerably higher than the usual generator with alumina column. Coating zirconium oxide on the surface of silica gel resulted in higher 99 Mo adsorption of this compound. 99m Tc is eluted with 0.9% NaCl, and the radionuclidic, radiochemical and chemical purities of the eluate were checked. This generator has a great potential as compared to the traditional alumina generators.

  7. Formation and characterization of vitreous materials prepared by the sol-gel technique

    International Nuclear Information System (INIS)

    Martinez, J.R.; Ruiz, J.F.; Cruz M, J.A. de la; Villasenor G, P.

    1999-01-01

    A full process of preparation and characterization of silica gel, which can be implemented in a experimental course for undergraduate laboratories is presented. Samples of silica gel and sol-gel derived SiO 2 films on glass substrates were fabricated and characterized using atomic force microscopy, Raman and Infrared absorption techniques. Raman and Infrared spectroscopy were used to analyze the local structure. The microstructure characteristics of the films, fabricated by dip-coating, were monitored using atomic force microscopy. The samples were prepared from alcoholic solutions of tetraethylortosilicate (TEOS) keeping the H 2 O/TEOS and Et-OH/TEOS molar ratios constant and equal to 11.66 and 4 respectively. (Author)

  8. Sol-gel prepared B2O3-SiO2 thin films for protection of copper substrates

    International Nuclear Information System (INIS)

    Gouda, M.; Ahmed, M.S.; Shahin, M.A.

    2000-01-01

    Full text.Borosilicate coating has potential for applications in the field of electronics, e.g., as passivation layers. One of the main difficulties for applying these films by the conventional melting process is the extensive volatilization of B 2 O 3 from the melt. In this work transparent borosilicate films of 2OB 2 O3.8OSiO 2 (in mole %). Prepared by the sole gel method, were applied onto copper substrates by dip-coating technique. The transparency of these films was very sensitive to the humidity of the atmosphere during the coating process. Transparent films were obtained below 20% relative humidity at 20 celsius degree. High temperature oxidation tests, at about 585 celsius degree stream of air, showed that the sol-gel prepared 2OB 2 O 3 .8OSiO 2 thin films are protective coating for copper substrates under fairly severe temperature gradient and oxidizing atmosphere. It was found that the protective action of these films depends on the film thickness

  9. Low dielectric loss in nano-Li-ferrite spinels prepared by sol–gel ...

    Indian Academy of Sciences (India)

    ... Refresher Courses · Symposia · Live Streaming. Home; Journals; Bulletin of Materials Science; Volume 39; Issue 1. Low dielectric loss in nano-Li-ferrite spinels prepared by sol–gel auto-combustion technique. Mamata Maisnam Nandeibam Nilima Maisnam Victory Sumitra Phanjoubam. Volume 39 Issue 1 February 2016 ...

  10. Supercritical fluid extraction of silicone oil from uranate microspheres prepared by sol-gel process

    International Nuclear Information System (INIS)

    Kumar, R.; Venkatakrishnan, R.; Sivaraman, N.; Srinivasan, T.G.; Vasudeva Rao, P.R.

    2005-01-01

    Supercritical fluid extraction of silicone oil from urania microspheres prepared through sol-gel route was investigated. The influence of pressure, temperature, and flow rate on the extraction efficiency was studied. Experimental conditions were optimised for the complete removal of silicone oil from urania microspheres. (author)

  11. Sol-gel synthesis of magnesium oxide-silicon dioxide glass compositions

    Science.gov (United States)

    Bansal, Narottam P.

    1988-01-01

    MgO-SiO2 glasses containing up to 15 mol pct MgO, which could not have been prepared by the conventional glass melting method due to the presence of stable liquid-liquid immiscibility, were synthesized by the sol-gel technique. Clear and transparent gels were obtained from the hydrolysis and polycondensation of silicon tetraethoxide (TEOS) and magnesium nitrate hexahydrate when the water/TEOS mole ratio was four or more. The gelling time decreased with increase in magnesium content, water/TEOS ratio, and reaction temperature. Magnesium nitrate hexahydrate crystallized out of the gels containing 15 and 20 mol pct MgO on slow drying. This problem was partially alleviated by drying the gels quickly at higher temperatures. Monolithic gel samples were prepared using glycerol as the drying control additive. The gels were subjected to various thermal treatments and characterized by several methods. No organic groups could be detected in the glasses after heat treatments to approx. 800 C, but trace amounts of hydroxyl groups were still present. No crystalline phase was found from X-ray diffraction in the gel samples to approx. 890 C. At higher temperatures, alpha quartz precipitated out as the crystalline phase in gels containing up to 10 mol pct MgO. The overall activation energy for gel formation in 10MgO-90SiO2 (mol pct) system for water/TEOS mole ratio of 7.5 was calculated to be 58.7 kJ/mol.

  12. Surface functionalization of carbon nanofibers by sol-gel coating of zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Shao Dongfeng [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China); Changzhou Textile Garment Institute, Changzhou 213164 (China); Wei Qufu [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China)], E-mail: qfwei@jiangnan.edu.cn; Zhang Liwei; Cai Yibing; Jiang Shudong [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China)

    2008-08-15

    In this paper the functional carbon nanofibers were prepared by the carbonization of ZnO coated PAN nanofibers to expand the potential applications of carbon nanofibers. Polyacrylonitrile (PAN) nanofibers were obtained by electrospinning. The electrospun PAN nanofibers were then used as substrates for depositing the functional layer of zinc oxide (ZnO) on the PAN nanofiber surfaces by sol-gel technique. The effects of coating, pre-oxidation and carbonization on the surface morphology and structures of the nanofibers were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Scanning electron microscopy (SEM), respectively. The results of SEM showed a significant increase of the size of ZnO nanograins on the surface of nanofibers after the treatments of coating, pre-oxidation and carbonization. The observations by SEM also revealed that ZnO nanoclusters were firmly and clearly distributed on the surface of the carbon nanofibers. FTIR examination also confirmed the deposition of ZnO on the surface of carbon nanofibers. The XRD analysis indicated that the crystal structure of ZnO nanograins on the surface of carbon nanofibers.

  13. Solar absorption and thermal emission properties of multiwall carbon nanotube/nickel oxide nanocomposite thin films synthesized by sol-gel process

    CSIR Research Space (South Africa)

    Roro, Kittessa T

    2012-05-01

    Full Text Available Multiwall carbon nanotubes (MWCNTs)/nickel oxide (NiO) nanocomposites were successfully prepared by a sol–gel process and coated on an aluminium substrate. The MWCNTs were chemically functionalized and then added into NiO alcogels, and magnetic...

  14. Sol-gel zinc oxide humidity sensors integrated with a ring oscillator circuit on-a-chip.

    Science.gov (United States)

    Yang, Ming-Zhi; Dai, Ching-Liang; Wu, Chyan-Chyi

    2014-10-28

    The study develops an integrated humidity microsensor fabricated using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS) process. The integrated humidity sensor consists of a humidity sensor and a ring oscillator circuit on-a-chip. The humidity sensor is composed of a sensitive film and branch interdigitated electrodes. The sensitive film is zinc oxide prepared by sol-gel method. After completion of the CMOS process, the sensor requires a post-process to remove the sacrificial oxide layer and to coat the zinc oxide film on the interdigitated electrodes. The capacitance of the sensor changes when the sensitive film adsorbs water vapor. The circuit is used to convert the capacitance of the humidity sensor into the oscillation frequency output. Experimental results show that the output frequency of the sensor changes from 84.3 to 73.4 MHz at 30 °C as the humidity increases 40 to 90%RH.

  15. Sol-Gel Zinc Oxide Humidity Sensors Integrated with a Ring Oscillator Circuit On-a-Chip

    Directory of Open Access Journals (Sweden)

    Ming-Zhi Yang

    2014-10-01

    Full Text Available The study develops an integrated humidity microsensor fabricated using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS process. The integrated humidity sensor consists of a humidity sensor and a ring oscillator circuit on-a-chip. The humidity sensor is composed of a sensitive film and branch interdigitated electrodes. The sensitive film is zinc oxide prepared by sol-gel method. After completion of the CMOS process, the sensor requires a post-process to remove the sacrificial oxide layer and to coat the zinc oxide film on the interdigitated electrodes. The capacitance of the sensor changes when the sensitive film adsorbs water vapor. The circuit is used to convert the capacitance of the humidity sensor into the oscillation frequency output. Experimental results show that the output frequency of the sensor changes from 84.3 to 73.4 MHz at 30 °C as the humidity increases 40 to 90%RH.

  16. Preparation of Barley Storage Protein, Hordein, for Analytical Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis

    DEFF Research Database (Denmark)

    Doll, Hans; Andersen, Bente

    1981-01-01

    The extraction, reduction, and alkylation of barley hordein for routine electrophoresis in sodium dodecyl sulfate-polyacrylamide gels were studied to set up a simple preparation procedure giving well-resolved bands in the electrophoresis gel. Hordein was extracted from single crushed seeds or flour...... by aqueous 50% propan-2-ol containing a Tris-borate buffer, pH 8.6. The presence of the buffer facilitates the consecutive complete reduction of the extracted protein in the alcohol. Reduction and alkylation in the buffer containing propan-2-ol give sharper bands in the electrophoresis than reduction...

  17. Polyacrylamide gel electrophoretic preparation of labelled and non-labelled peptides for radioimmunoassay

    International Nuclear Information System (INIS)

    Besch, W.; Woltanski, K.P.; Keilacker, H.; Kohnert, K.D.

    1986-01-01

    Radioiodinated polypeptide hormones, such as insulin, glucagon, human growth hormone, and human C-peptide are employed for radioimmunoassays for investigation of hormonal alterations in states of disturbed carbohydrate metabolism. Iodination was performed using chloramine T. Iodination products of these polypeptide hormones and, for preparation of standard material, native human C-peptide from cadaver pancreases were fractionated by polyacrylamide gel electrophoresis at pH 8.9. Disc electrophoresis in 24 cm long gel rods resulted in stable tracers with high specific activity as well as homogeneous standard material being highly suitable for radioimmunoassays. (author)

  18. Porphyrinosilica and metalloporphyrinosilica: hybrid organic-inorganic materials prepared by sol-gel processing

    Science.gov (United States)

    Iamamoto; Sacco; Biazzotto; Ciuffi; Serra

    2000-01-01

    New materials porphyrinosilica and metalloporphyrinosilica template have been obtained by a sol-gel processing where functionalyzed porphyrins and metalloporphyrins "building blocks" were assembled into a three-dimensional silicate network. The optimized conditions for preparation of these materials are revised. The monomer precursors porphyrinopropylsilyl and metalloporphyrinopropylsilyl preparation reactions and subsequent one pot sol-gel processing with tetraethoxysilane are discussed. In the case of metalloporphyrins the nitrogen base coordinates to the central metal and acts as a template in the molecular imprinting technique. UV-visible absorption spectroscopy, thermogravimetric analysis, electron paramagnetic resonance, nuclear magnetic spectra, infrared spectra, luminescence spectra, surface area and electron spectroscopy imaging of the materials are used to characterize the prepared materials. The catalytic activities of these metalloporphyrinosilica-template are compared.

  19. Porphyrinosilica and metalloporphyrinosilica: hybrid organic-inorganic materials prepared by sol-gel processing

    Directory of Open Access Journals (Sweden)

    YASSUKO IAMAMOTO

    2000-03-01

    Full Text Available New materials porphyrinosilica and metalloporphyrinosilica template have been obtained by a sol-gel processing where functionalyzed porphyrins and metalloporphyrins "building blocks" were assembled into a three-dimensional silicate network. The optimized conditions for preparation of these materials are revised. The monomer precursors porphyrinopropylsilyl and metalloporphyrinopropylsilyl preparation reactions and subsequent one pot sol-gel processing with tetraethoxysilane are discussed. In the case of metalloporphyrins the nitrogen base coordinates to the central metal and acts as a template in the molecular imprinting technique. UV-visible absorption spectroscopy, thermogravimetric analysis, electron paramagnetic resonance, nuclear magnetic spectra, infrared spectra, luminescence spectra, surface area and electron spectroscopy imaging of the materials are used to characterize the prepared materials. The catalytic activities of these metalloporphyrinosilica- template are compared.

  20. Preparation and studies of Co(II) and Co(III)-substituted barium ferrite prepared by sol-gel method

    International Nuclear Information System (INIS)

    Teh, Geok Bee; Nagalingam, Saravanan; Jefferson, David A.

    2007-01-01

    The sol-gel preparative method was employed to synthesise Co(II) and Co(III)-substituted barium ferrite. This method was attempted to achieve higher homogeneity of the final product. Samples of substituted ferrites were characterised by various experimental techniques including high resolution transmission electron microscopy, X-ray diffraction analysis, magnetometry and thermal gravimetric analysis. The microstructural changes induced by such substitution are also discussed

  1. Preparation and studies of Co(II) and Co(III)-substituted barium ferrite prepared by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Teh, Geok Bee [Department of Bioscience and Chemistry, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, 53300 Kuala Lumpur (Malaysia)]. E-mail: tehgb@mail.utar.edu.my; Nagalingam, Saravanan [Department of Bioscience and Chemistry, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, 53300 Kuala Lumpur (Malaysia); Jefferson, David A. [Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW (United Kingdom)

    2007-01-15

    The sol-gel preparative method was employed to synthesise Co(II) and Co(III)-substituted barium ferrite. This method was attempted to achieve higher homogeneity of the final product. Samples of substituted ferrites were characterised by various experimental techniques including high resolution transmission electron microscopy, X-ray diffraction analysis, magnetometry and thermal gravimetric analysis. The microstructural changes induced by such substitution are also discussed.

  2. Preparation of porous titanium oxide films onto indium tin oxide for application in organic photovoltaic devices

    Energy Technology Data Exchange (ETDEWEB)

    Macedo, Andreia G. [Laboratorio de Dispositivos Nanoestruturados, Departamento de Fisica, Universidade Federal do Parana, Curitiba, Parana (Brazil); Mattos, Luana L.; Spada, Edna R.; Serpa, Rafael B.; Campos, Cristiani S. [Laboratorio de Sistemas Nanoestruturados, Departamento de Fisica, Universidade Federal de Santa Catarina, Florianopolis, Santa Catarina (Brazil); Grova, Isabel R.; Ackcelrud, Leni [Laboratorio de Polimeros Paulo Scarpa, Departamento de Quimica, Universidade Federal do Parana, Curitiba, Parana (Brazil); Reis, Francoise T.; Sartorelli, Maria L. [Laboratorio de Sistemas Nanoestruturados, Departamento de Fisica, Universidade Federal de Santa Catarina, Florianopolis, Santa Catarina (Brazil); Roman, Lucimara S., E-mail: lsroman@fisica.ufpr.br [Laboratorio de Dispositivos Nanoestruturados, Departamento de Fisica, Universidade Federal do Parana, Curitiba, Parana (Brazil)

    2012-05-01

    In this work, porous ordered TiO{sub 2} films were prepared through sol gel route by using a monolayer of polystyrene spheres as template on indium-tin oxide/glass substrate. These films were characterized by SEM, AFM, Raman spectroscopy, UV-vis absorbance and XRD. The UV-vis absorbance spectrum show a pseudo band gap (PBG) with maxima at 460 nm arising from the light scattering and partial or total suppression of the photon density of states, this PBG can be controlled by the size of the pore. We also propose the use of this porous film as electron acceptor electrode in organic photovoltaic cells; we show that devices prepared with porous titania displayed higher efficiencies than devices using compact titania films as electrode. Such behaviour was observed in both bilayer and bulk heterojunction devices.

  3. Preparation of porous titanium oxide films onto indium tin oxide for application in organic photovoltaic devices

    International Nuclear Information System (INIS)

    Macedo, Andreia G.; Mattos, Luana L.; Spada, Edna R.; Serpa, Rafael B.; Campos, Cristiani S.; Grova, Isabel R.; Ackcelrud, Leni; Reis, Françoise T.; Sartorelli, Maria L.; Roman, Lucimara S.

    2012-01-01

    In this work, porous ordered TiO 2 films were prepared through sol gel route by using a monolayer of polystyrene spheres as template on indium-tin oxide/glass substrate. These films were characterized by SEM, AFM, Raman spectroscopy, UV-vis absorbance and XRD. The UV-vis absorbance spectrum show a pseudo band gap (PBG) with maxima at 460 nm arising from the light scattering and partial or total suppression of the photon density of states, this PBG can be controlled by the size of the pore. We also propose the use of this porous film as electron acceptor electrode in organic photovoltaic cells; we show that devices prepared with porous titania displayed higher efficiencies than devices using compact titania films as electrode. Such behaviour was observed in both bilayer and bulk heterojunction devices.

  4. Correlation of the oxidation state of cerium in sol-gel glasses as a function of thermal treatment via optical spectroscopy and XANES studies.

    Science.gov (United States)

    Assefa, Zerihun; Haire, R G; Caulder, D L; Shuh, D K

    2004-07-01

    Sol-gel glass matrices containing lanthanides have numerous technological applications and their formation involves several chemical facets. In the case of cerium, its ability to exist in two different oxidation states or in mixed valence state provides additional complexities for the sol-gel process. The oxidation state of cerium present during different facets of preparation of sol-gel glasses, and also as a function of the starting oxidation state of cerium added, were studied both by optical spectroscopy and X-ray absorption near-edge structures (XANES). The findings acquired by each approach were compared. The primary focus was on the redox chemistries associated with sample preparation, gelation, and thermal treatment. When Ce3+ is introduced into the starting sols, the trivalent state normally prevails in the wet and room temperature-dried gels. Heating in air at >100 degrees C can generate a light yellow coloration with partial oxidation to the tetravalent state. Above 200 degrees C and up to approximately 1000 degrees C, cerium is oxidized to its tetravalent state. In contrast, when tetravalent cerium is introduced into the sol, both the wet and room temperature-dried gels lose the yellow-brown color of the initial ceric ammonium nitrate solution. When the sol-gel is heated to 110 degrees C it turns yellowish as the cerium tends to be re-oxidized. The yellow color is believed to represent the effect of oxidation and oligomerization of the cerium-silanol units in the matrix. The luminescence properties are also affected by these changes, the details of which are reported herein.

  5. Microcontroller based instrumentation for the fuel pin preparation facility by sol-gel method

    International Nuclear Information System (INIS)

    Suhasini, B.; Prabhakar Rao, J.; Srinivas, K.C.

    2009-01-01

    The fuel pin preparation facility by Sol-Gel route has been set up at Chemistry Group at Indira Gandhi Centre for Atomic Research, Kalpakkam. Sol-Gel, a solution-gelation process involves conversion of solutions of nitrates of uranium-plutonium (at 0 deg C) into gel microspheres. To measure the exact quantities of the above solutions and to ensure their temperatures, a variety of sensors have been used at various stages in the plant. To monitor and acquire the data of process parameters used in the production and for an automated operation of the plant, a PC (master)-microcontroller (slave) based instrumentation has been developed along with acquisition software and a GU interface developed in Visual Basic. (author)

  6. Mullite fibres preparation by aqueous sol-gel process and activation energy of mullitization

    International Nuclear Information System (INIS)

    Tan Hongbin; Ding Yaping; Yang Jianfeng

    2010-01-01

    Mullite fibres were prepared by sol-gel process using aluminum carboxylates (ACs) and silica sol. ACs was synthesized from dissolving aluminum powder in a mixture of formic acid and oxalic acid using aluminum chloride hexahydrate as catalyst. A molar ratio of 1:2:1 for aluminum, formic acid and oxalic acid was optimized to obtain clear solution and viscous ACs sol for fibres synthesis. Thermogravimetry-differential scanning calorimetry (TG-DSC), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM) analysis were used to characterize the properties of the gel and ceramic fibres. The gel fibres completely transformed to mullite at 1200 o C, with a smooth surface and uniform diameter. The activation energy for mullite formation in precursor gel fibres was determined by means of differential thermal analysis. The value obtained, E a = 741.4 kJ/mol, was lower than most data reported in the literatures, which was attributed to the silica-alumina micro-phase separation when organic acids decomposed during gel fibres heating.

  7. Stimuli responsive ion gels based on polysaccharides and other polymers prepared using ionic liquids and deep eutectic solvents.

    Science.gov (United States)

    Prasad, Kamalesh; Mondal, Dibyendu; Sharma, Mukesh; Freire, Mara G; Mukesh, Chandrakant; Bhatt, Jitkumar

    2018-01-15

    Ion gels and self-healing gels prepared using ionic liquids (ILs) and deep eutectic solvents (DESs) have been largely investigated in the past years due to their remarkable applications in different research areas. Herewith we provide an overview on the ILs and DESs used for the preparation of ion gels, highlight the preparation and physicochemical characteristics of stimuli responsive gel materials based on co-polymers and biopolymers, with special emphasis on polysaccharides and discuss their applications. Overall, this review summarizes the fundamentals and advances in ion gels with switchable properties prepared using ILs or DESs, as well as their potential applications in electrochemistry, in sensing devices and as drug delivery vehicles. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Preparation of Metal Immobilized Orange Waste Gel for Arsenic(V Removal From Water

    Directory of Open Access Journals (Sweden)

    Biplob Kumar Biswas

    2014-05-01

    Full Text Available Abstract - The toxicity of arsenic is known to be a risk to aquatic flora and fauna and to human health even in relatively low concentration. In this research an adsorption gel was prepared from agricultural waste material (orange waste through simple chemical modification in the view to remove arsenic (V from water. Orange waste was crushed into small particles and saponified with Ca(OH2 to prepare saponified orange waste, which was further modified by immobilizing gadolinium(III to obtain desired adsorption material (Gd(III-immobilized SOW gel. The effective pH range for arsenic adsorption was found to be 7.5 – 8.5. Adsorption capacity of the gel was evaluated to be 0.45 mol-arsenic (V/kg. Dynamic adsorption of arsenic (V in column-mode was conducted and a dynamic capacity was found to be 0.39 mol/kg. Elution of arsenate was tested after complete saturation of the column packed with gadolinium-immobilized orange waste adsorption gel. A complete elution of arsenate was achieved with the help of 1 M HCl and 28 times pre-concentration factor was attained. This study showed that a cheap and abundant agro-industrial waste material could be successfully employed for the remediation of arsenic pollution in aquatic environment. Keywords: Arsenic; Orange waste; Gadolinium(III; Adsorption; Elution.

  9. Obtention and characterization of dried gels prepared with whey proteins, honey and hydrocolloids mixture.

    Science.gov (United States)

    Rodriguez, Ana C; Torrez Irigoyen, Martín R; Navarro, Alba S; Yamul, Diego K

    2017-11-01

    Large amounts of honey and liquid whey derived from the dairy industry are produced in Argentina. Honey is exported in bulk and whey is transformed into whey protein concentrates and isolates. The objective of this work was to investigate the effect of pH, composition and storage time on the properties of dried gels with honey, whey proteins and hydrocolloids. Color properties varied according to pH and composition. The fracture stress of dried gels prepared with corn starch was higher than that of gels prepared with guar gum in all conditions assayed. Young's modulus was higher at pH 7 for both compositions and increased with storage time. Rubbery characteristics were found in dried gels with guar gum, while both corn starch and guar gum made the microstructure rougher. Multivariate analysis showed that samples could be grouped by pH. Panelists preferred pH 7 products over acidic ones, and no significant differences in sensory properties were found using either corn starch or guar gum in the formulation. The results demonstrated that it is possible to generate a new product, which may open new applications for honey and whey in food formulations. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  10. Development of novel biocompatible hybrid nanocomposites based on polyurethane-silica prepared by sol gel process

    Energy Technology Data Exchange (ETDEWEB)

    Rashti, Ali [Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Yahyaei, Hossein [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Firoozi, Saman [Department of Tissue Engineering & Regenerative Medicine, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ramezani, Sara [Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Rahiminejad, Ali [Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Karimi, Roya [Department of Tissue Engineering and Applied Cell Science, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Farzaneh, Khadijeh [Tehran Heart Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Mohseni, Mohsen [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Ghanbari, Hossein, E-mail: hghanbari@tums.ac.ir [Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Tehran Heart Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Medical Biomaterials Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2016-12-01

    Due to high biocompatibility, polyurethane has found many applications, particularly in development of biomedical devices. A new nanocomposite based on thermoset polyurethane and silica nanoparticles was synthesized using sol-gel method. Sol-gel process was fulfilled in two acidic and basic conditions by using tetraethylorthosilicate (TEOS) and trimethoxyisocyanatesilane as precursors. The hybrid films characterized for mechanical and surface properties using tensile strength, contact angle, ATR-FTIR and scanning electron microscopy. Biocompatibility and cytotoxicity of the hybrids were assessed using standard MTT, LDH and TUNEL assays. The results revealed that incorporation of silica nanoparticles was significantly improved tensile strength and mechanical properties of the hybrids. Based on the contact angle results, silica nanoparticles increased hydrophilicity of the hybrids. Biocompatibility by using human lung epithelial cell line (MRC-5) demonstrated that the hybrids were significantly less cytotoxic compared to pristine polymer as tested by MTT and LDH assays. TUNEL assay revealed no signs of apoptosis in all tested samples. The results of this study demonstrated that incorporation of silica nanoparticles into polyurethane lead to the enhancement of biocompatibility, indicating that these hybrids could potentially be used in biomedical field in particular as a new coating for medical implants. - Highlights: • Nanocomposites based on polyurethane and nanosilica prepared by sol-gel method fabricated • Addition of inorganic phase improved mechanical properties. • Nanosilica prepared by sol-gel method increased hydrophilicity. • By adding nanosilica to polyurethane biocompatibility increased significantly.

  11. Template-directed formation of functional complex metal-oxide nanostructures by combination of sol-gel processing and spin coating

    International Nuclear Information System (INIS)

    Choi, Y.C.; Kim, J.; Bu, S.D.

    2006-01-01

    We report the template-based formation of functional complex metal-oxide nanostructures by a combination of sol-gel processing and spin coating. This method employs the spin-coating of a sol-gel solution into an anodic aluminum oxide membrane (SSAM). Various metal-oxide nanowires and nanotubes with a high aspect-ratio were prepared. The aspect-ratios of the PbO 2 nanowires and Pb(Zr 0.52 Ti 0.48 )O 3 nanowires were about 300 and 400, respectively, and their diameters were about 50 nm. The fabricated PbTiO 3 nanotubes have a relatively constant wall thickness of about 20 nm with an outer diameter of about 60 nm. The deposition time for all of the fabricated metal-oxide nanowires and nanotubes is less than 120 s, which is far shorter than those required in both the sol-gel dipping and sol-gel electrophoretic methods. These results indicate that the SSAM method can be a versatile pathway to prepare functional complex metal-oxide nanowires and nanotubes with a high aspect-ratio. The possible formation process for the one-dimensional nanostructures by SSAM is discussed

  12. EXAFS and XRD studies of nanocrystalline cerium oxide: the effect of preparation method on the microstructure

    International Nuclear Information System (INIS)

    Savin, S.L.P.; Chadwick, A.V.; Smith, M.E.; O'Dell, L.A.

    2007-01-01

    There is considerable interest in nanocrystalline materials due to their unusual properties, such as enhanced ionic conductivity in the case of nanocrystalline ionic solids. This has potential commercial applications, particularly for oxide ion conductors. However, a detailed knowledge of the microstructure is important in fully understanding the novel properties exhibited by nanocrystalline materials. The final microstructure of a material is dependent on the preparation method used, for example, sol-gel and ball-milling methods are commonly used in the preparation of nanocrystalline oxides. Additionally, there is a problem in maintaining the materials in nanocrystalline form when they are subjected to elevated temperatures. We have been exploring strategies to restrict the growth of nanocrystalline oxides and have found that adding a small amount of an inert material, e.g. SiO 2 or Al 2 O 3 , is particularly effective. We will report XRD and EXAFS studies of nanocrystalline ceria prepared by sol-gel, sol-gel pinned and ball-milling methods and the effect of preparation method on the final microstructure. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Comparative study of ZnO thin films prepared by different sol-gel route

    Directory of Open Access Journals (Sweden)

    F Esmaieli Ghodsi

    2012-03-01

    Full Text Available   Retraction Notice    The paper "Comparative study of ZnO thin films prepared by different sol-gel route" by H. Absalan and F. E. Ghodsi, which appeared in Iranian Journal of Physics Research, Vol. 11, No. 4, 423-428 (in Farsi is translation of the paper "Comparative Study of ZnO Thin Films Prepared by Different Sol-Gel Route" by F. E. Ghodsi and H. Absalan, which appeared in ACTA PHYSICA POLONICA A, Vol 118 (2010 (in English and for this reason is retracted from this journal.The corresponding author  (and also the first author is the only responsible person for this action.   

  14. Evaluation of sol–gel based magnetic 45S5 bioglass and bioglass–ceramics containing iron oxide

    International Nuclear Information System (INIS)

    Shankhwar, Nisha; Srinivasan, A.

    2016-01-01

    Multicomponent oxide powders with nominal compositions of (45 − x)·SiO_2·24.5CaO·24.5Na_2O·6P_2O_5xFe_2O_3 (in wt.%) were prepared by a modified sol–gel procedure. X-ray diffraction (XRD) patterns and high resolution transmission electron microscope images of the sol–gel products show fully amorphous structure for Fe_2O_3 substitutions up to 2 wt.%. Sol–gel derived 43SiO_2·24.5CaO·24.5Na_2O·6P_2O_5·2Fe_2O_3 glass (or bioglass 45S5 with SiO_2 substituted with 2 wt.% Fe_2O_3), exhibited magnetic behavior with a coercive field of 21 Oe, hysteresis loop area of 33.25 erg/g and saturation magnetization of 0.66 emu/g at an applied field of 15 kOe at room temperature. XRD pattern of this glass annealed at 850 °C for 1 h revealed the formation of a glass–ceramic containing sodium calcium silicate and magnetite phases in nanocrystalline form. Temperature dependent magnetization and room temperature electron spin resonance data have been used to obtain information on the magnetic phase and distribution of iron ions in the sol–gel glass and glass–ceramic samples. Sol–gel derived glass and glass–ceramic exhibit in-vitro bioactivity by forming a hydroxyapatite surface layer under simulated physiological conditions and their bio-response is superior to their melt quenched bulk counterparts. This new form of magnetic bioglass and bioglass ceramics opens up new and more effective biomedical applications. - Highlights: • Bioglass 45S5 containing 2 wt.% Fe_2O_3 is prepared by sol–gel route. • Fully amorphous bioglass exhibits spontaneous magnetization. • Gel powders with more than 2 wt.% Fe_2O_3 formed glass–ceramics. • γ-Fe_2O_3 in bioglass transformed irreversibly to magnetite upon heat treatment. • In vitro bioactivity of sol–gel samples is superior to their bulk counterparts.

  15. Improvement of physical properties of IGZO thin films prepared by excimer laser annealing of sol–gel derived precursor films

    International Nuclear Information System (INIS)

    Tsay, Chien-Yie; Huang, Tzu-Teng

    2013-01-01

    Indium gallium zinc oxide (IGZO) transparent semiconductor thin films were prepared by KrF excimer laser annealing of sol–gel derived precursor films. Each as-coated film was dried at 150 °C in air and then annealed using excimer laser irradiation. The influence of laser irradiation energy density on surface conditions, optical transmittances, and electrical properties of laser annealed IGZO thin films were investigated, and the physical properties of the excimer laser annealed (ELA) and the thermally annealed (TA) thin films were compared. Experimental results showed that two kinds of surface morphology resulted from excimer laser annealing. Irradiation with a lower energy density (≤250 mJ cm −2 ) produced wavy and irregular surfaces, while irradiation with a higher energy density (≥350 mJ cm −2 ) produced flat and dense surfaces consisting of uniform nano-sized amorphous particles. The explanation for the differences in surface features and film quality is that using laser irradiation energy to form IGZO thin films improves the film density and removes organic constituents. The dried IGZO sol–gel films irradiated with a laser energy density of 350 mJ/cm 2 had the best physical properties of all the ELA IGZO thin films. The mean resistivity of the ELA 350 thin films (4.48 × 10 3 Ω cm) was lower than that of TA thin films (1.39 × 10 4 Ω cm), and the average optical transmittance in the visible range (90.2%) of the ELA 350 thin films was slightly higher than that of TA thin films (89.7%). - Highlights: • IGZO semiconductor films were prepared by laser annealing of sol–gel derived films. • Surface roughness and resistivity of ELA samples were affected by energy density. • The ELA 350 IGZO film exhibited the best properties among all of ELA IGZO films. • Transmittance and resistivity of ELA 350 films are greater than those of TA films

  16. Effect of oxidizer on grain size and low temperature DC electrical conductivity of tin oxide nanomaterial synthesized by gel combustion method

    International Nuclear Information System (INIS)

    Rajeeva, M. P.; Jayanna, H. S.; Ashok, R. L.; Naveen, C. S.; Bothla, V. Prasad

    2014-01-01

    Nanocrystalline Tin oxide material with different grain size was synthesized using gel combustion method by varying the fuel (C 6 H 8 O 7 ) to oxidizer (HNO 3 ) molar ratio by keeping the amount of fuel as constant. The prepared samples were characterized by using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Energy Dispersive Analysis X-ray Spectroscopy (EDAX). The effect of fuel to oxidizer molar ratio in the gel combustion method was investigated by inspecting the grain size of nano SnO 2 powder. The grain size was found to be reduced with the amount of oxidizer increases from 0 to 6 moles in the step of 2. The X-ray diffraction patterns of the calcined product showed the formation of high purity tetragonal tin (IV) oxide with the grain size in the range of 12 to 31 nm which was calculated by Scherer's formula. Molar ratio and temperature dependence of DC electrical conductivity of SnO 2 nanomaterial was studied using Keithley source meter. DC electrical conductivity of SnO 2 nanomaterial increases with the temperature from 80K to 300K. From the study it was observed that the DC electrical conductivity of SnO 2 nanomaterial decreases with the grain size at constant temperature

  17. Ultralow-density SiO2 aerogels prepared by a two-step sol-gel process

    International Nuclear Information System (INIS)

    Wang Jue; Li Qing; Shen Jun; Zhou Bin; Chen Lingyan; Jiang; Weiyang

    1996-01-01

    Low density SiO 2 gels are prepared by a two-step sol-gel process from TEOS. The influence of various solution ratios on the gelation process is investigated. The comparative characterization of gels using different solvent, such as ethanol, acetone and methyl cyanide, is also given. The ultralow-density SiO 2 aerogels with density less than 10 kg/m 3 are prepared by CO 2 supercritical drying technique. The structure difference between SiO 2 aerogels prepared by conventional single-step process and the two-step process is also presented

  18. Mucoadhesive in situ gel formulation for vaginal delivery of clotrimazole: formulation, preparation, and in vitro/in vivo evaluation.

    Science.gov (United States)

    Rençber, Seda; Karavana, Sinem Yaprak; Şenyiğit, Zeynep Ay; Eraç, Bayri; Limoncu, Mine Hoşgör; Baloğlu, Esra

    2017-06-01

    The purpose of this study was to develop a suitable mucoadhesive in situ gel formulation of clotrimazole (CLO) for the treatment of vaginal candidiasis. For this aim, the mixture of poloxamer (PLX) 407 and 188 were used to prepare in situ gels. Hydroxypropyl methylcellulose (HPMC) K100M or E50 was added to in situ gels in 0.5% ratio to improve the mucoadhesive and mechanical properties of formulations and to prolong the residence time in vaginal cavity. After the preparation of mucoadhesive in situ gels; gelation temperature/time, viscosity, mechanical, mucoadhesive, syringeability, spreadibility and rheological properties, in vitro release behavior, and anticandidal activities were determined. Moreover vaginal retention of mucoadhesive in situ gels was investigated with in vivo distribution studies in rats. Based on the obtained results, it was found that gels prepared with 20% PLX 407, 10% PLX 188 and 0.5% HPMC K100M/E50 might be suitable for vaginal administration of CLO. In addition, the results of in vivo distribution studies showed that gel formulations remained on the vaginal mucosa even 24 h after application. In conclusion, the mucoadhesive in situ gels of CLO would be alternative candidate for treatment of vaginal candidiasis since it has suitable gel properties with good vaginal retention.

  19. Synthesis and characterization of mixtures of cobalt and titanium oxides by mechanical alloyed and Sol-Gel

    International Nuclear Information System (INIS)

    Basurto S, R.; Bonifacio M, J.; Fernandez V, S. M.

    2009-01-01

    The mechanical alloyed techniques continued by combustion and Sol-Gel method, were used for the synthesis of CoTiO 3 . With the first technique was used Co 3 O 4 obtained in a balls mill SPEX in argon atmosphere, using cobalt nitrate and urea, the combustion is realized at 400 and 500 C, the characterization by X-ray diffraction showed the obtaining of the valence oxide mixed of cobalt with crystallite size from 10 to 12.5 nm and the particle size of 60 to 75 nm was obtained by scanning electron microscopy. To prepare the CoTiO 3 , the obtained Co 3 O 4 was mixed with TiO 2 on a relationship in weight (1:1) and with a milling time of 2.5 h and the combustion at 800 C. the mixed oxide of titanium cobalt was also obtained by the Sol-Gel technique starting from cobalt chloride and titanium propoxide in acetic-water acid, the gel is burned to temperature of 300, 500, 700 and 900 C, finding that this last temperature it is that provides the compound with crystalline size from 50 to 75 nm. (Author)

  20. The influence of the matrix structure on the oxidation of aniline in a silica sol-gel composite

    International Nuclear Information System (INIS)

    Widera, J.; Kijak, A.M.; Ca, D.V.; Pacey, G.E.; Taylor, R.T.; Perfect, H.; Cox, J.A.

    2005-01-01

    Mesoporous and microporous silica matrices were formed on indium tin oxide electrodes for liquid-phase voltammetry and as monoliths for solid-state voltammetry of aniline. The pore structure, which was verified by scanning probe microscopy and by surface area measurement, was directed by either control of pH during sol-gel processing or by inclusion of a templating agent. Whether aniline was included as a dopant in the sol-gel or as a component of the contacting liquid, the pore size influenced the coupling of the product of its electrochemical oxidation. With microporous silica, the dominant products were dimers and related short-chain products whereas with mesoporous silica, polymerization was suggested. As a step toward the formation of polyaniline (PANI) that is covalently anchored to the sol-gel, the electrochemistry of aniline was investigated using composites prepared from sols comprising tetraethyl orthosilicate (TEOS), 3-aminophenyl-[3-triethoxylsilyl)-propyl] urea (ormosil), and aniline in various ratios. Combinatorial chemistry identified that the optimum combination of silica precursors in terms of obtaining PANI was a 1:12 mole ratio of ormosil:TEOS

  1. Carbon-Nickel oxide nanocomposites: Preparation and charecterisation

    CSIR Research Space (South Africa)

    Tile, N

    2011-07-01

    Full Text Available Nanocomposite materials have wide range of applications in solar energy conversion. In this work, C-NiO nanocomposite coatings are prepared using sol-gel synthesis and deposited on aluminium substrates using a spin coater. The coatings are prepared...

  2. Gel-aided sample preparation (GASP)--a simplified method for gel-assisted proteomic sample generation from protein extracts and intact cells.

    Science.gov (United States)

    Fischer, Roman; Kessler, Benedikt M

    2015-04-01

    We describe a "gel-assisted" proteomic sample preparation method for MS analysis. Solubilized protein extracts or intact cells are copolymerized with acrylamide, facilitating denaturation, reduction, quantitative cysteine alkylation, and matrix formation. Gel-aided sample preparation has been optimized to be highly flexible, scalable, and to allow reproducible sample generation from 50 cells to milligrams of protein extracts. This methodology is fast, sensitive, easy-to-use on a wide range of sample types, and accessible to nonspecialists. © 2014 The Authors. PROTEOMICS published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Study of hafnium (IV) oxide nanoparticles synthesized by polymerized complex and polymer precursor derived sol-gel methods

    KAUST Repository

    Ramos-Gonzá lez, R.; Garcí a-Cerda, L. A.; Alshareef, Husam N.; Gnade, Bruce E.; Quevedo-Ló pez, Manuel Angel Quevedo

    2010-01-01

    This work reports the preparation and characterization of hafnium (IV) oxide (HfO2) nanoparticles grown by derived sol-gel routes that involves the formation of an organic polymeric network. A comparison between polymerized complex (PC) and polymer precursor (PP) methods is presented. For the PC method, citric acid (CA) and ethylene glycol (EG) are used as the chelating and polymerizable reagents, respectively. In the case of PP method, poly(acrylic acid) (PAA) is used as the chelating reagent. In both cases, different precursor gels were prepared and the hafnium (IV) chloride (HfCl4) molar ratio was varied from 0.1 to 1.0 for the PC method and from 0.05 to 0.5 for the PP method. In order to obtain the nanoparticles, the precursors were heat treated at 500 and 800 °C. The thermal characterization of the precursor gels was carried out by thermogravimetric analysis (TGA) and the structural and morphological characterization by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD patterns of the samples obtained by both methods shows the formation of HfO2 at 500 °C with monoclinic crystalline phase. The PC method exhibited also the cubic phase. Finally, the HfO2 nanoparticles size (4 to 11 nm) was determined by TEM and XRD patterns. © (2010) Trans Tech Publications.

  4. Study of hafnium (IV) oxide nanoparticles synthesized by polymerized complex and polymer precursor derived sol-gel methods

    KAUST Repository

    Ramos-González, R.

    2010-03-01

    This work reports the preparation and characterization of hafnium (IV) oxide (HfO2) nanoparticles grown by derived sol-gel routes that involves the formation of an organic polymeric network. A comparison between polymerized complex (PC) and polymer precursor (PP) methods is presented. For the PC method, citric acid (CA) and ethylene glycol (EG) are used as the chelating and polymerizable reagents, respectively. In the case of PP method, poly(acrylic acid) (PAA) is used as the chelating reagent. In both cases, different precursor gels were prepared and the hafnium (IV) chloride (HfCl4) molar ratio was varied from 0.1 to 1.0 for the PC method and from 0.05 to 0.5 for the PP method. In order to obtain the nanoparticles, the precursors were heat treated at 500 and 800 °C. The thermal characterization of the precursor gels was carried out by thermogravimetric analysis (TGA) and the structural and morphological characterization by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD patterns of the samples obtained by both methods shows the formation of HfO2 at 500 °C with monoclinic crystalline phase. The PC method exhibited also the cubic phase. Finally, the HfO2 nanoparticles size (4 to 11 nm) was determined by TEM and XRD patterns. © (2010) Trans Tech Publications.

  5. {sup 90}Y microspheres prepared by sol-gel method, promising medical material for radioembolization of liver malignancies

    Energy Technology Data Exchange (ETDEWEB)

    Łada, Wiesława, E-mail: w.lada@ichtj.waw.pl [Institute of Nuclear Chemistry and Technology, 03-195 Warsaw, Dorodna 16 (Poland); Iller, Edward [National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Andrzej Sołtan 7 (Poland); Wawszczak, Danuta [Institute of Nuclear Chemistry and Technology, 03-195 Warsaw, Dorodna 16 (Poland); Konior, Marcin, E-mail: marcin.konior@polatom.pl [National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Andrzej Sołtan 7 (Poland); Dziel, Tomasz [National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Andrzej Sołtan 7 (Poland)

    2016-10-01

    A new technology for the production of radiopharmaceutical {sup 90}Y microspheres in the form of spherical yttrium oxide grains obtained by sol-gel method has been described. The authors present and discuss the results of investigations performed in the development of new production technology of yttrium microspheres and determination of their physic-chemical properties. The final product has the structure of spherical yttrium oxide grains with a diameter 25–100 μm, is stable and free from contaminants. Irradiation of 20 mg samples of grains with diameter of 20–50 μm in the thermal neutron flux of 1.7 × 10{sup 14} cm{sup −2} s{sup −1} at the core of MARIA research nuclear reactor allowed to obtain microspheres labelled with the {sup 90}Y isotope on the way of the nuclear reaction {sup 89}Y(n, γ){sup 90}Y. Specific activity of irradiated microspheres has been determined by application of absolute triple to double coincidence ratio method (TDCR) and has been evaluated at 190 MBq/mg Y. {sup 90}Y microspheres prepared by the proposed technique can be regarded as a promising medical material for radioembolization of liver malignancies. - Highlights: • Sol-gel methods for preparation of spherical yttrium trioxide grains have been proposed. • Determination condition for irradiation {sup 89}Y{sub 2}O{sub 3} grains in nuclear reactor • Evaluation of specific activity of {sup 90}Y microspheres • Estimation of {sup 90}Y microspheres as promising medical material for radioembolization.

  6. Fast and facile preparation of CTAB based gels and their applications in Au and Ag nanoparticles synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Ravi Kant, E-mail: rkupadhyay85@gmail.com [Department of Chemistry, School of Natural Sciences, Shiv Nadar University, Gautam Budh Nagar, 201314 Uttar Pradesh (India); Soin, Navneet, E-mail: n.soin@bolton.ac.uk [Knowledge Centre for Materials Chemistry (KCMC), Institute for Materials Research and Innovation (IMRI), University of Bolton, Deane Road, Bolton BL3 5AB (United Kingdom); Saha, Susmita, E-mail: ssaha@bose.res.in [Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098 (India); Barman, Anjan, E-mail: abarman@bose.res.in [Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098 (India); Sinha Roy, Susanta, E-mail: susanta.roy@snu.edu.in [Department of Physics, School of Natural Sciences, Shiv Nadar University, Gautam Budh Nagar, 201314 Uttar Pradesh (India)

    2015-04-15

    We have demonstrated that the gel-like mesophase of Cetyltrimethylammonium bromide (CTAB) can be synthesized by judicial adjustment of water to surfactant molar ratio (W{sub 0}), without using any additional salts, gelating agents or co-surfactants. Gel formation was found to be highly dependent on the water to surfactant molar ratio (W{sub 0}), with the lowest value of W{sub 0} (41.5) resulting in rapid gel formation. Environmental scanning electron microscope (ESEM) analysis revealed that the gel was comprised of interconnected cylindrical structures. The presence of hydrogen bonding in the gel-like mesophase was confirmed by Fourier Transform Infrared spectroscopy (FTIR) analysis. Rheology measurements revealed that all the gel samples were highly viscoelastic in nature. Furthermore, Au and Ag containing CTAB gels were explored as precursors for the preparation of spherical Gold (Au) and Silver (Ag) nanoparticles using Sodium borohydride (NaBH{sub 4}) as reducing agent. The effects of NaBH{sub 4} concentration on the particle size and morphology of the Au and Ag nanoparticles have also been studied. - Highlights: • A facile synthesis of CTAB based gel-like mesophase is reported. • CTAB gels were obtained by adjusting water to surfactant molar ratio (W{sub 0}). • FTIR analysis revealed that hydrogen bonding plays a key role in gel formation. • Au, Ag nanoparticles were synthesized by using CTAB gel and NaBH{sub 4}.

  7. Cobalt sulfide aerogel prepared by anion exchange method with enhanced pseudocapacitive and water oxidation performances

    Science.gov (United States)

    Gao, Qiuyue; Shi, Zhenyu; Xue, Kaiming; Ye, Ziran; Hong, Zhanglian; Yu, Xinyao; Zhi, Mingjia

    2018-05-01

    This work introduces the anion exchange method into the sol-gel process for the first time to prepare a metal sulfide aerogel. A porous Co9S8 aerogel with a high surface area (274.2 m2 g‑1) and large pore volume (0.87 cm3 g‑1) has been successfully prepared by exchanging cobalt citrate wet gel in thioacetamide and subsequently drying in supercritical ethanol. Such a Co9S8 aerogel shows enhanced supercapacitive performance and catalytic activity toward oxygen evolution reaction (OER) compared to its oxide aerogel counterpart. High specific capacitance (950 F g‑1 at 1 A g‑1), good rate capability (74.3% capacitance retention from 1 to 20 A g‑1) and low onset overpotential for OER (220 mV) were observed. The results demonstrated here have implications in preparing various sulfide chalcogels.

  8. Preparation and Evaluation of Valsartan Liquid Filling Formulations for Soft Gels

    Directory of Open Access Journals (Sweden)

    Jyothi Sanaboina

    2013-01-01

    Full Text Available The present investigation includes the preparation of liquid filling formulations for soft gels using an antihypertensive drug, valsartan (VAL, in order to improve its dissolution properties and thereby its bioavailability. Formulations were prepared using excipients like polyethylene glycol 400 (PEG 400, propylene glycol (PG, polyvinylpyrrolidone (PVP K-30, antioxidants, ethanol, and purified water. Prepared formulations were evaluated for appearance, pH, drug content percentage, viscosity, stability, and in vitro dissolution studies. The compatibility between the drug and excipients in formulations was confirmed by FTIR spectra. The drug contents were in the range of 99.62-99.63 and the viscosity was in the range of 60.9–591.7 cps with all the formulations developed. Formulations containing 10 mg PVP K 30 gave better dissolution properties when compared to formulations without PVP K 30, and a complete drug dissolution was observed within 10 min and followed the first-order release kinetics. Stability studies were conducted for selected formulations (F4–F9 for a period of 6 months at room temperature (~30°C/65% RH. From the studies, it can be concluded that VAL liquid filling formulations for soft gels were successfully prepared with in vitro dissolution properties superior when compared to VAL itself.

  9. Optimizing human synovial fluid preparation for two-dimensional gel electrophoresis.

    Science.gov (United States)

    Chen, Carl Pc; Hsu, Chih-Chin; Yeh, Wen-Lin; Lin, Hsiu-Chu; Hsieh, Sen-Yung; Lin, Shih-Cherng; Chen, Tai-Tzung; Chen, Max Jl; Tang, Simon Ft

    2011-10-11

    Proteome analysis is frequently applied in identifying the proteins or biomarkers in knee synovial fluids (SF) that are associated with osteoarthritis and other arthritic disorders. The 2-dimensional gel electrophoresis (2-DE) is the technique of choice in these studies. Disease biomarkers usually appear in low concentrations and may be masked by high abundant proteins. Therefore, the main aim of this study was to find the most suitable sample preparation method that can optimize the expression of proteins on 2-DE gels that can be used to develop a reference proteome picture for non-osteoarthritic knee synovial fluid samples. Proteome pictures obtained from osteoarthritic knee synovial fluids can then be compared with the reference proteome pictures obtained in this study to assist us in identifying the disease biomarkers more correctly. The proteomic tool of 2-DE with immobilized pH gradients was applied in this study. A total of 12 2-DE gel images were constructed from SF samples that were free of osteoarthritis. In these samples, 3 were not treated with any sample preparation methods, 3 were treated with acetone, 3 were treated with 2-DE Clean-Up Kit, and 3 were treated with the combination of acetone and 2-D Clean-Up Kit prior to 2-DE analysis. Gel images were analyzed using the PDQuest Basic 8.0.1 Analytical software. Protein spots that were of interest were excised from the gels and sent for identification by mass spectrometry. Total SF total protein concentration was calculated to be 21.98 ± 0.86 mg/mL. The untreated SF samples were detected to have 456 ± 33 protein spots on 2-DE gel images. Acetone treated SF samples were detected to have 320 ± 28 protein spots, 2-D Clean-Up Kit treated SF samples were detected to have 413 ± 31 protein spots, and the combined treatment method of acetone and 2-D Clean-Up Kit was detected to have 278 ± 26 protein spots 2-DE gel images. SF samples treated with 2-D Clean-Up Kit revealed clearer presentation of the isoforms

  10. Optimizing Human Synovial Fluid Preparation for Two-Dimensional Gel Electrophoresis

    Directory of Open Access Journals (Sweden)

    Chen Max JL

    2011-10-01

    Full Text Available Abstract Background Proteome analysis is frequently applied in identifying the proteins or biomarkers in knee synovial fluids (SF that are associated with osteoarthritis and other arthritic disorders. The 2-dimensional gel electrophoresis (2-DE is the technique of choice in these studies. Disease biomarkers usually appear in low concentrations and may be masked by high abundant proteins. Therefore, the main aim of this study was to find the most suitable sample preparation method that can optimize the expression of proteins on 2-DE gels that can be used to develop a reference proteome picture for non-osteoarthritic knee synovial fluid samples. Proteome pictures obtained from osteoarthritic knee synovial fluids can then be compared with the reference proteome pictures obtained in this study to assist us in identifying the disease biomarkers more correctly. Results The proteomic tool of 2-DE with immobilized pH gradients was applied in this study. A total of 12 2-DE gel images were constructed from SF samples that were free of osteoarthritis. In these samples, 3 were not treated with any sample preparation methods, 3 were treated with acetone, 3 were treated with 2-DE Clean-Up Kit, and 3 were treated with the combination of acetone and 2-D Clean-Up Kit prior to 2-DE analysis. Gel images were analyzed using the PDQuest Basic 8.0.1 Analytical software. Protein spots that were of interest were excised from the gels and sent for identification by mass spectrometry. Total SF total protein concentration was calculated to be 21.98 ± 0.86 mg/mL. The untreated SF samples were detected to have 456 ± 33 protein spots on 2-DE gel images. Acetone treated SF samples were detected to have 320 ± 28 protein spots, 2-D Clean-Up Kit treated SF samples were detected to have 413 ± 31 protein spots, and the combined treatment method of acetone and 2-D Clean-Up Kit was detected to have 278 ± 26 protein spots 2-DE gel images. SF samples treated with 2-D Clean-Up Kit

  11. Preparation and Performance of an Adsorption Type Gel Plugging Agent as Enhanced Oil Recovery Chemical

    Directory of Open Access Journals (Sweden)

    Xiaoping Qin

    2015-01-01

    Full Text Available A novel adsorption type gel plugging agent (ATGPA was prepared using acrylamide (AM, acrylic acid (AA, diallyl dimethyl ammonium chloride (DMDAAC, 2-acrylamido-2-methylpropanesulfonate (AMPS, formaldehyde (HCHO, resorcinol (C6H6O2, and thiocarbamide (CH4N2S as raw materials under mild conditions. ATGPA was characterized by infrared (IR spectroscopy, elemental analysis, and scanning electron microscope (SEM. It was found that ATGPA exhibited higher elastic modulus (G′ and viscous modulus (G′′ than AM/AA gel plugging agent (AAGPA under the same scanning frequency. It was also found that ATGPA had moderate temperature resistance and salt tolerance. Core plugging tests results indicated that ATGPA could achieve up to higher plugging rate (PR than AAGPA (97.2% versus 95.7% at 65°C. In addition, ATGPA possessed stronger antiscouring ability by core plugging experiments at 65°C.

  12. Strong poly(ethylene oxide) based gel adhesives via oxime cross-linking.

    Science.gov (United States)

    Ghosh, Smita; Cabral, Jaydee D; Hanton, Lyall R; Moratti, Stephen C

    2016-01-01

    There is a demand for materials to replace or augment the use of sutures and staples in surgical procedures. Currently available commercial surgical adhesives provide either high bond strength with biological toxicity or polymer and protein-based products that are biologically acceptable (though with potential sensitizing potential) but have much reduced bond strength. It is desirable to provide novel biocompatible and biodegradable surgical adhesives/sealants capable of high strength with minimal immune or inflammatory response. In this work, we report the end group derivatization of 8-arm star PEOs with aldehyde and amine end groups. Gels were prepared employing the Schiff-base chemistry between the aldehydes and the amines. Gel setting times, swelling behavior and rheological characterization were carried out for these gels. The mechanical-viscoelastic properties were found to be directly proportional to the crosslinking density of the gels, the 10K PEO gel was stiffer in comparison to the 20K PEO gel. The adhesive properties of these gels were tested using porcine skin and showed excellent adhesion properties. Cytotoxicity studies were carried out for the individual gel components using two different methods: (a) Crystal Violet Staining assay (CVS assay) and (b) impedance and cell index measurement by the xCELLigence system at concentrations >5%. Gels prepared by mixing 20% w/w solutions were also tested for cytotoxicity. The results revealed that the individual gel components as well as the prepared gels and their leachables were non-cytotoxic at these concentrations. This work presents a new type of glue that is aimed at surgery applications using a water soluble star shaped polymer. It show excellent adhesion to skin and is tough and easy to use. We show that it is very biocompatible based on tests on live human cells, and could therefore in principle be used for internal surgery. Comparison with other reported and commercial glues shows that it is stronger

  13. Comparison of optical properties of Eu3+ ions in the silica gel glasses obtained by different preparation techniques

    International Nuclear Information System (INIS)

    Legendziewicz, J.; Sokolnicki, J.; Keller, B.; Borzechowska, M.; Strek, W.

    1996-01-01

    Silica-gel glasses doped with Eu 3+ ions were obtained by different preparation techniques. The absorption, emission and excitation spectra of the obtained glasses were measured in the range of 77-300 K. The energy levels diagrams of Eu 3+ ions were derived. An intensity analysis of f-f transitions was performed. In particular, polymeric structure behaviour of europium compounds entrapped in silica gel glasses was temperature controlled during the preparation of glasses. Their optical properties were investigated. (author)

  14. Synthesis and characterization of hollow {alpha}-Fe{sub 2}O{sub 3} sub-micron spheres prepared by sol-gel

    Energy Technology Data Exchange (ETDEWEB)

    Leon, Lizbet, E-mail: lizbetlf@gmail.com; Bustamante, Angel; Osorio, Ana; Olarte, G. S. [Universidad Nacional Mayor de San Marcos (Peru); Santos Valladares, Luis De Los, E-mail: ld301@cam.ac.uk; Barnes, Crispin H. W. [University of Cambridge, Cavendish Laboratory (United Kingdom); Majima, Yutaka [Tokyo Institute of Technology, Materials and Structures Laboratory (Japan)

    2011-11-15

    In this work we report the preparation of magnetic hematite hollow sub-micron spheres ({alpha}-Fe{sub 2}O{sub 3}) by colloidal suspensions of ferric nitrate nine-hydrate (Fe(NO{sub 3}){sub 3}{center_dot}9H{sub 2}O) particles in citric acid solution by following the sol-gel method. After the gel formation, the samples were annealed at different temperatures in an oxidizing atmosphere. Annealing at 180 Degree-Sign C resulted in an amorphous phase, without iron oxide formation. Annealing at 250 Degree-Sign C resulted in coexisting phases of hematite, maghemite and magnetite, whereas at 400 Degree-Sign C, only hematite and maghemite were found. Pure hematite hollow sub-micron spheres with porous shells were formed after annealing at 600 Degree-Sign C. The characterization was performed by X-ray diffraction (XRD), Moessbauer spectroscopy (MS) and scanning electron microscopy (SEM).

  15. Characterization of mucoadhesive nasal gels containing midazolam hydrochloride prepared from Linum usitatissimum L. mucilage

    Directory of Open Access Journals (Sweden)

    Shyamoshree Basu

    2011-12-01

    Full Text Available Nasal drug delivery systems prepared from natural materials are gaining importance in the field of pharmaceutical technology. Mucilage isolated from Linum usitatissimum L. (LUM seeds was reported to be an effective natural mucoadhesive agent. The present study deals with a comparison of various characteristics of nasal gels containing midazolam hydrochloride (HCl prepared from mucoadhesive agent extracted from Linum usitatissimum L. seeds and synthetic polymers like HPMC and Carbopol 934P in terms of texture profile analysis, mucoadhesive strength, and in vivo drug absorption profiles. It was observed that gels formulated with the natural mucilage showed better results than the synthetic gels in all aspects like hardness, adhesiveness, cohesiveness and mucoadhesive strength. The absolute bioavailability of midazolam hydrochloride from the natural gel was 97.55% whereas that of synthetic gels was 57.33% and 76.81% respectively.Sistemas de liberação nasal preparados com produtos naturais estão ganhando importância no campo da tecnologia farmacêutica. A mucilagem isolada de sementes de Linum usitatissimum L. (LUM mostrou-se agente mucoadesivo eficaz. O presente estudo trata da comparação de várias características de géis nasais contendo cloridrato de midazolam preparados com agente mucoadesivo extraído das sementes de Linum usitatissimum L. e com polímeros sintéticos, como HPMC e Carbopol 943P, com relação ao perfil de textura, força mucoadesiva e perfis de absorção do fármaco in vivo. Observou-se que os géis formulados com mucilagem natural apresentam melhores resultados do que os sintéticos em todos os aspectos, como dureza, adesão, coesão e força mucoadesiva. A biodisponibilidade absoluta do cloridrato de midazolam a partir do gel natural foi de 97,55%, enquanto que nos géis sintéticos foi de 57,33% e 76,81%, respectivamente.

  16. Magnetic iron oxide nanoparticles (MIONs) cross-linked natural polymer-based hybrid gel beads: Controlled nano anti-TB drug delivery application.

    Science.gov (United States)

    Kesavan, Mookkandi Palsamy; Ayyanaar, Srinivasan; Vijayakumar, Vijayaparthasarathi; Dhaveethu Raja, Jeyaraj; Annaraj, Jamespandi; Sakthipandi, Kathiresan; Rajesh, Jegathalaprathaban

    2018-04-01

    The nanosized rifampicin (RIF) has been prepared to increase the solubility in aqueous solution, which leads to remarkable enhancement of its bioavailability and their convenient delivery system studied by newly produced nontoxic, biodegradable magnetic iron oxide nanoparticles (MIONs) cross-linked polyethylene glycol hybrid chitosan (mCS-PEG) gel beads. The functionalization of both nano RIF and mCS-PEG gel beads were studied using various spectroscopic and microscopic techniques. The size of prepared nano RIF was found to be 70.20 ± 3.50 nm. The mechanical stability and swelling ratio of the magnetic gel beads increased by the addition of PEG with a maximum swelling ratio of 38.67 ± 0.29 g/g. Interestingly, this magnetic gel bead has dual responsive assets in the nano drug delivery application (pH and the magnetic field). As we expected, magnetic gel beads show higher nano drug releasing efficacy at acidic medium (pH = 5.0) with maximum efficiency of 71.00 ± 0.87%. This efficacy may also be tuned by altering the external magnetic field and the weight percentage (wt%) of PEG. These results suggest that such a dual responsive magnetic gel beads can be used as a potential system in the nano drug delivery applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1039-1050, 2018. © 2017 Wiley Periodicals, Inc.

  17. Evaluation of sol-gel based magnetic 45S5 bioglass and bioglass-ceramics containing iron oxide.

    Science.gov (United States)

    Shankhwar, Nisha; Srinivasan, A

    2016-05-01

    Multicomponent oxide powders with nominal compositions of (45-x)·SiO2·24.5CaO·24.5Na2O·6P2O5xFe2O3 (in wt.%) were prepared by a modified sol-gel procedure. X-ray diffraction (XRD) patterns and high resolution transmission electron microscope images of the sol-gel products show fully amorphous structure for Fe2O3 substitutions up to 2 wt.%. Sol-gel derived 43SiO2·24.5CaO·24.5Na2O·6P2O5·2Fe2O3 glass (or bioglass 45S5 with SiO2 substituted with 2 wt.% Fe2O3), exhibited magnetic behavior with a coercive field of 21 Oe, hysteresis loop area of 33.25 erg/g and saturation magnetization of 0.66 emu/g at an applied field of 15 kOe at room temperature. XRD pattern of this glass annealed at 850 °C for 1h revealed the formation of a glass-ceramic containing sodium calcium silicate and magnetite phases in nanocrystalline form. Temperature dependent magnetization and room temperature electron spin resonance data have been used to obtain information on the magnetic phase and distribution of iron ions in the sol-gel glass and glass-ceramic samples. Sol-gel derived glass and glass-ceramic exhibit in-vitro bioactivity by forming a hydroxyapatite surface layer under simulated physiological conditions and their bio-response is superior to their melt quenched bulk counterparts. This new form of magnetic bioglass and bioglass ceramics opens up new and more effective biomedical applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Electron beam crosslinked gels-Preparation, characterization and their effect on the mechanical, dynamic mechanical and rheological properties of rubbers

    International Nuclear Information System (INIS)

    Mitra, Suman; Chattopadhyay, Santanu; Sabharwal, Sunil; Bhowmick, Anil K.

    2010-01-01

    Electron beam (EB) crosslinked natural rubber (NR) gels were prepared by curing NR latex with EB irradiation over a range of doses from 2.5 to 20 kGy using butyl acrylate as sensitizer. The NR gels were systematically characterized by solvent swelling, dynamic light scattering, mechanical and dynamic mechanical properties. These gels were introduced in virgin NR and styrene butadiene rubber (SBR) matrices at 2, 4, 8 and 16 phr concentration. Addition of the gels improved the mechanical and dynamic mechanical properties of NR and SBR considerably. For example, 16 phr of 20 kGy EB-irradiated gel-filled NR showed a tensile strength of 3.53 MPa compared to 1.85 MPa of virgin NR. Introduction of gels in NR shifted the glass transition temperature to a higher temperature. A similar effect was observed in the case of NR gel-filled SBR systems. Morphology of the gel-filled systems was studied with atomic force microscopy. The NR gels also improved the processability of the virgin rubbers greatly. Both the shear viscosity and the die swell values of EB-irradiated gel-filled NR and SBR were lower than their virgin counterparts as investigated by capillary rheometer.

  19. Electron beam crosslinked gels-Preparation, characterization and their effect on the mechanical, dynamic mechanical and rheological properties of rubbers

    Energy Technology Data Exchange (ETDEWEB)

    Mitra, Suman; Chattopadhyay, Santanu [Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302 (India); Sabharwal, Sunil [Radiation Technology Development Section, Bhabha Atomic Research Center, Trombay, Mumbai 400085 (India); Bhowmick, Anil K., E-mail: anilkb@rtc.iitkgp.ernet.i [Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302 (India)

    2010-03-15

    Electron beam (EB) crosslinked natural rubber (NR) gels were prepared by curing NR latex with EB irradiation over a range of doses from 2.5 to 20 kGy using butyl acrylate as sensitizer. The NR gels were systematically characterized by solvent swelling, dynamic light scattering, mechanical and dynamic mechanical properties. These gels were introduced in virgin NR and styrene butadiene rubber (SBR) matrices at 2, 4, 8 and 16 phr concentration. Addition of the gels improved the mechanical and dynamic mechanical properties of NR and SBR considerably. For example, 16 phr of 20 kGy EB-irradiated gel-filled NR showed a tensile strength of 3.53 MPa compared to 1.85 MPa of virgin NR. Introduction of gels in NR shifted the glass transition temperature to a higher temperature. A similar effect was observed in the case of NR gel-filled SBR systems. Morphology of the gel-filled systems was studied with atomic force microscopy. The NR gels also improved the processability of the virgin rubbers greatly. Both the shear viscosity and the die swell values of EB-irradiated gel-filled NR and SBR were lower than their virgin counterparts as investigated by capillary rheometer.

  20. Preparation of Reduced Graphene Oxides as Electrode Materials for Supercapacitors

    KAUST Repository

    Bai, Yaocai

    2012-01-01

    Reduced graphene oxide as outstanding candidate electrode material for supercapacitor has been investigated. This thesis includes two topics. One is that three kinds of reduced graphene oxides were prepared by hydrothermal reduction under different

  1. Influence of protecting gel film on oxidation of zirconium alloys

    Czech Academy of Sciences Publication Activity Database

    Frank, H.; Weishauptová, Zuzana; Vrtílková, V.

    2007-01-01

    Roč. 360, č. 3 (2007), s. 282-292 ISSN 0022-3115 R&D Projects: GA ČR GA106/04/0043 Institutional research plan: CEZ:AV0Z30460519 Keywords : fuel cladding * corrosion * Zirconium oxide Subject RIV: JF - Nuclear Energetics Impact factor: 1.643, year: 2007

  2. An improved method of preparation of nanoparticular metal oxide catalysts

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention concerns an improved method of preparation of nanoparticular vanadium oxide/anatase titania catalysts having a narrow particle size distribution. In particular, the invention concerns preparation of nanoparticular vanadium oxide/anatase titania catalyst precursors comprising...... combustible crystallization seeds upon which the catalyst metal oxide is coprecipitated with the carrier metal oxide, which crystallization seeds are removed by combustion in a final calcining step....

  3. Mesoporous metal oxides and processes for preparation thereof

    Energy Technology Data Exchange (ETDEWEB)

    Suib, Steven L.; Poyraz, Altug Suleyman

    2018-03-06

    A process for preparing a mesoporous metal oxide, i.e., transition metal oxide. Lanthanide metal oxide, a post-transition metal oxide and metalloid oxide. The process comprises providing an acidic mixture comprising a metal precursor, an interface modifier, a hydrotropic ion precursor, and a surfactant; and heating the acidic mixture at a temperature and for a period of time sufficient to form the mesoporous metal oxide. A mesoporous metal oxide prepared by the above process. A method of controlling nano-sized wall crystallinity and mesoporosity in mesoporous metal oxides. The method comprises providing an acidic mixture comprising a metal precursor, an interface modifier, a hydrotropic ion precursor, and a surfactant; and heating the acidic mixture at a temperature and for a period of time sufficient to control nano-sized wall crystallinity and mesoporosity in the mesoporous metal oxides. Mesoporous metal oxides and a method of tuning structural properties of mesoporous metal oxides.

  4. Magnetic properties of Co-Ni alloy nanoparticles prepared by the sol-gel technique

    International Nuclear Information System (INIS)

    Sangregorio, C.; Fernandez, C. de Julian; Battaglin, G.; De, G.; Gatteschi, D.; Mattei, G.; Mazzoldi, P.

    2004-01-01

    The magnetic properties of Co, Ni and Co x Ni 1-x alloy nanoparticles with different composition (0 < x < 1), prepared by the sol-gel route, were investigated. ZFC and FC magnetization measurements show that the blocking temperature increases with the Co content, while a maximum in the anisotropy constant was found for x=0.7. Room temperature FMR measurements, suggest that in samples with larger Co content (x≥0.66) interparticle interactions play a relevant role in determining their magnetic properties

  5. Magnetic properties of Co-Ni alloy nanoparticles prepared by the sol-gel technique

    Energy Technology Data Exchange (ETDEWEB)

    Sangregorio, C. E-mail: claudio.sangregorio@unifi.it; Fernandez, C. de Julian; Battaglin, G.; De, G.; Gatteschi, D.; Mattei, G.; Mazzoldi, P

    2004-05-01

    The magnetic properties of Co, Ni and Co{sub x}Ni{sub 1-x} alloy nanoparticles with different composition (0 < x < 1), prepared by the sol-gel route, were investigated. ZFC and FC magnetization measurements show that the blocking temperature increases with the Co content, while a maximum in the anisotropy constant was found for x=0.7. Room temperature FMR measurements, suggest that in samples with larger Co content (x{>=}0.66) interparticle interactions play a relevant role in determining their magnetic properties.

  6. Thermal properties and water repellency of cotton fabric prepared through sol-gel method

    Directory of Open Access Journals (Sweden)

    Gu Jia-Li

    2016-01-01

    Full Text Available Cotton fabrics were treated by one-step sol-gel method. The pure silica hydrosol and phosphorus-doped hydrosol were prepared with the addition of a hydrophobic hexadecyltrimethoxysilane to decrease the surface energy of cotton fabric. The thermal properties and water repellency of treated cotton fabric were characterized by thermo-gravimetric analysis, micro combustion, limiting oxygen index, and contact angle measurement. The results showed that cotton fabric treated by phosphorus-doped silica hydrosol had excellent flame retardance, and the water repellence was apparently improved with the addition of hexadecyltrimethoxysilane.

  7. Evolution of the local structure of ferric gels and polymers during the crystallisation of iron oxides. Application to uranium trapping

    International Nuclear Information System (INIS)

    Combes, Jean-Marie

    1988-01-01

    A first part of this research thesis reports the study of the structure of the main iron oxides and oxy-hydroxides, and of the protocols for the synthesis of ferric gels. The second part reports a topological approach by EXAFS (Extended X-Ray Absorption Fine Structure) of the structure of Mn and Fe oxides and oxy-hydroxides. The third part reports the study of the formation of ferric oxides from aqueous solutions by using a polyhedral approach by X-ray absorption spectroscopy in the case of hydrolysis and formation of ferric gels, and in the case of haematite formation from ferric gels. The next parts respectively report the study of the local structure of gels synthesised from iron(II), and the study of the local structure of natural ferric gels. Then, the author reports the study of sites of uranium bonding on ferric gels [fr

  8. Preparation and characterization of sol-gel derived TiO2 films

    International Nuclear Information System (INIS)

    Hong, Y.J.; Brungs, M.P.; Chaplin, R.P.; Sizgek, E.

    2001-01-01

    Crack-free transparent titania films have been prepared through a new sol-gel process combined with hydrogen peroxide treatment. Hydrogen peroxide and HCl were used to dissolve amorphous titania powder which is obtained by drying common sol-gel titania sol. The peroxo-titania sol produced a thicker film than the common sol-gel titania sol due to a higher degree of condensation. Film thickness could be further increased by controlled drying conditions of the amorphous titania powder or 'aging' the sol. Polyethylene glycol (PEG) and chemical additives were effective in controlling condensation rate by preventing rapid condensation during curing of the film. When these two components were incorporated, it was possible to create a 0.5μm transparent film and PEG could also control the porosity of the film. The cured film was analysed by XRD and Raman spectroscopy. In order to measure the reflective index and thickness of the titania film, an ellipsometer was used. Copyright (2001) The Australian Ceramic Society

  9. Determination of Insulator-to-Semiconductor Transition in Sol-Gel Oxide Semiconductors Using Derivative Spectroscopy.

    Science.gov (United States)

    Lee, Woobin; Choi, Seungbeom; Kim, Kyung Tae; Kang, Jingu; Park, Sung Kyu; Kim, Yong-Hoon

    2015-12-23

    We report a derivative spectroscopic method for determining insulator-to-semiconductor transition during sol-gel metal-oxide semiconductor formation. When an as-spun sol-gel precursor film is photochemically activated and changes to semiconducting state, the light absorption characteristics of the metal-oxide film is considerable changed particularly in the ultraviolet region. As a result, a peak is generated in the first-order derivatives of light absorption ( A' ) vs. wavelength (λ) plots, and by tracing the peak center shift and peak intensity, transition from insulating-to-semiconducting state of the film can be monitored. The peak generation and peak center shift are described based on photon-energy-dependent absorption coefficient of metal-oxide films. We discuss detailed analysis method for metal-oxide semiconductor films and its application in thin-film transistor fabrication. We believe this derivative spectroscopy based determination can be beneficial for a non-destructive and a rapid monitoring of the insulator-to-semiconductor transition in sol-gel oxide semiconductor formation.

  10. Fundamental electrochemiluminescence characteristics of fluorine-doped tin oxides synthesized by sol-gel combustion.

    Science.gov (United States)

    Moon, B H; Chaoumead, A; Sung, Y M

    2013-10-01

    Fluorine-doped tin oxide (FTO) materials synthesized by sol-gel combustion method were investigated for electrochemical luminescence (ECL) application. Effects of sol-gel combustion conditions on the structures and morphology of the porous FTO (p-FTO) materials were studied. ECL efficiency of p-FTO-based cell was about 251 cd/m2 at 4 V bias, which is higher than the sell using only FTO electrodes (102.8 cd/m2). The highest intensity of the emitting light was obtained at the wavelength of about 610 nm. The porous FTO layer was effective for increasing ECL intensities.

  11. Mixed U/Pu oxide fabrication facility for gel-sphere-pac fuel

    International Nuclear Information System (INIS)

    1978-09-01

    This paper describes a conceptual plant which uses the gel-sphere-pac process to fabricate mixed oxide (MOX) fuel and covers (1) fabrication of co-processed MOX fuel and (2) fabrication of co-processed spiked MOX fuel, using 60 Co. The report describes: the fuel fabrication process and plant layout, including scrap and waste processing; and maintenance safety and ventilation measures. A description of the conversion of U and Pu nitrate using a gel sphere process is given in Appendix A

  12. Simple and Efficient Synthesis of Iron Oxide-Coated Silica Gel Adsorbents for Arsenic Removal: Adsorption Isotherms and Kinetic Study

    Energy Technology Data Exchange (ETDEWEB)

    Arifin, Eric; Lee, Jiukyu [Interdisciplinary Program in Nanoscience and Technology, Virginia (United States); Cha, Jinmyung [Seoul National Univ., Seoul (Korea, Republic of)

    2013-08-15

    Iron oxide (ferrihydrite, hematite, and magnetite) coated silica gels were prepared using a low-cost, easily-scalable and straightforward method as the adsorbent material for arsenic removal application. Adsorption of the anionic form of arsenic oxyacids, arsenite (AsO{sup 2-}) and arsenate (AsO{sub 4}{sup -3}), onto hematite coated silica gel was fitted against non-linear 3-parameter-model Sips isotherm and 2-parameter-model Langmuir and Freundlich isotherm. Adsorption kinetics of arsenic could be well described by pseudo-second-order kinetic model and value of adsorption energy derived from non-linear Dubinin-Radushkevich isotherm suggests chemical adsorption. Although arsenic adsorption process was not affected by the presence of sulfate, chloride, and nitrate anions, as expected, bicarbonate and silicate gave moderate negative effects while the presence of phosphate anions significantly inhibited adsorption process of both arsenite and arsenate. When the actual efficiency to remove arsenic was tested against 1 L of artificial arsenic-contaminated groundwater (0.6 mg/L) in the presence competing anions, the reasonable amount (20 g) of hematite coated silica gel could reduce arsenic concentration to below the WHO permissible safety limit of drinking water of 10 μg/L without adjusting pH and temperature, which would be highly advantageous for practical field application.

  13. Study of gels of molybdenum with cerium in the preparation of generators of 99Mo-99mTc

    International Nuclear Information System (INIS)

    Moraes, Vanessa; Marczewski, Barbara; Dias, Carla Roberta; Osso Junior, Joao Alberto

    2005-01-01

    99m Tc has ideal nuclear properties for organ imaging in nuclear medicine, and it is obtained from the 99 Mo- 99m Tc generator. Four different types of generators are available: chromatographic that uses 99 Mo from fission of uranium; MEK solvent extraction; Tc 2 O 7 sublimation; gel chromatographic. This work presents the preparation of gel generators of molybdenum with cerium and characterization of the gels: mass ratio between molybdenum and cerium, structure, size of particles and elution percentage of 99m Tc after irradiating the gels. Eight gels were prepared at the same temperature of 50 deg C with concentrations of NaOH of 2 and 4 mol/L, mass ratio of 0.31 and 0.38 and final pH of 3.5 and 4.5. The analysis of the results proved that these gels are not adequate for preparation of the generators of 99 Mo- 99m Tc, since the elution percentages are low, when compared with the gel of molybdenum with zirconium.(author)

  14. Effect of Organic Solvents in Preparation of Silica-Based Chemical Gel Decontaminates for Decontamination of Nuclear Facilities

    International Nuclear Information System (INIS)

    Yoon, Suk Bon; Jung, Chong Hun; Kim, Chang Ki; Choi, Byung Seon; Lee, Kune Woo; Moon, Jei Kwon

    2011-01-01

    Decontamination of nuclear facilities is necessary to reduce the radiation field during normal operations and decommissioning of complex equipment such as stainless steel components, other iron-based steel and alloys, metal surfaces, structural materials and so on. Chemical decontamination technology in particular is a highly effective method to remove the radioactive contamination through a chemical dissolution or a redox reaction. However, this method has the serious drawback due to the generation of large amounts of the radioactive liquid wastes. Recently, a few literatures have been reported for the preparation of the chemical gel decontaminants to reduce the amount of the radioactive liquid wastes and to enhance the decontamination efficiency through increasing the contact time between the gels and the radioactive contaminants. In the preparation of the chemical gels, the control of the viscosity highly depends on the amount of a coviscosifier used among the components of the chemical gels consisted of a viscosifier, a coviscosifier, and a chemical decontaminant. In this works, a new effective method for the preparation of the chemical gel was investigated by introducing the organic solvents. The mixture solution of the coviscosifier and organic solvent was more effective in the control of the viscosity compared with that of the coviscosifier only in gels. Furthermore, the decontamination efficiency of the chemical gels measured by using the multi-channel analyzer (MCA) showed the high decontamination factor for Co-60 and Cs-137 contaminated on the surface of the stainless steel 304

  15. Outcome of temperature variation on sol-gel prepared CuO nanostructure properties (optical and dielectric)

    Energy Technology Data Exchange (ETDEWEB)

    Bibi, Maryam [Nano Synthesis Laboratory, Department of Physics, National University of Sciences and Technology, Islamabad (Pakistan); Javed, Qurat-ul-Ain, E-mail: quratulain@sns.nust.edu.pk [Nano Synthesis Laboratory, Department of Physics, National University of Sciences and Technology, Islamabad (Pakistan); Abbas, Hussain [Institute of Avionics & Aeronautics (IAA), Air University, Islamabad (Pakistan); Baqi, Sabah [Nano Synthesis Laboratory, Department of Physics, National University of Sciences and Technology, Islamabad (Pakistan)

    2017-05-01

    The optical and dielectric properties of Copper Oxide (CuO) have made it a fascinating material to be used in solar energy harvesting, gas sensing, optoelectronics and catalytical applications. Focusing on the cost-effectiveness of Sol-gel method, it is employed for nanostructured CuO production. Effect of changing temperature is observed on the formation mechanism of CuO and its properties. The temperature range of 300 °C–500 °C was used in annealing of samples to produce defect free CuO nanomaterial. Prepared material was investigated using phase characterization (X-ray diffraction ‘XRD’) technique, scanning electron microscopy (SEM), UV–Visible absorption spectroscopy and LCR meter. A structural change in prepared CuO was observed from cluster formation to Nano-fibrils by increase in annealing temperature. 11.99 nm–29.17 nm crystallites of CuO were attained by using Debye Scherer formula. A large band gap of 3.15 eV was achieved by increasing the annealing temperature upto 400 °C. For better solar energy harvest, wide band gapped CuO structures are proved to be functional and practical materials. The fabricated CuO nanostructures were found suitable to be used in devices for stabilizing circuit designs for sensitive appliances as well as micro electromechanical systems (mems). - Highlights: • CuO was synthesized by using sol gel method post growth annealing process. • XRD and SEM characterizations confirm the successful synthesis of CuO. • Change in morphology was observed with varying annealing temperature. • Improved optical and dielectric properties were observed.

  16. Determination of Ideal Broth Formulations Needed to Prepare Hydrous Cerium Oxide Microspheres via the Internal Gelation Process

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Jack Lee [ORNL; Chi, Anthony [ORNL

    2009-02-01

    A simple test tube methodology was used to determine optimum process parameters for preparing hydrous cerium oxide microspheres via the internal gelation process.1 Broth formulations of cerium ammonium nitrate [(NH4)2Ce(NO3)6], hexamethylenetetramine, and urea were found that can be used to prepare hydrous cerium oxide gel spheres in the temperature range of 60 to 90 C. A few gel-forming runs were made in which microspheres were prepared with some of these formulations to be able to equate the test-tube gelation times to actual gelation times. These preparations confirmed that the test-tube methodology is reliable for determining the ideal broth formulations.

  17. Aloe vera gel improves behavioral deficits and oxidative status in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Tabatabaei, Seyed Reza Fatemi; Ghaderi, Shahab; Bahrami-Tapehebur, Mohammad; Farbood, Yaghoob; Rashno, Masome

    2017-12-01

    Oxidative stress has a major role in progression of diabetes-related behavioral deficits. It has been suggested that Aloe vera has anti-diabetic, antioxidative, and neuroprotective effects. The present study was designed to determine the effects of Aloe vera gel on behavioral functions, oxidative status, and neuronal viability in the hippocampus of streptozotocin (STZ)-induced diabetic rats. Fifty five adult male Wistar rats were randomly divided into five groups, including: control (normal saline 8ml/kg/day; P.O.), diabetic (normal saline 8ml/kg/day; P.O.), Aloe vera gel (100mg/kg/day; P.O.), diabetic+Aloe vera gel (100mg/kg/day; P.O.) and diabetic+NPH insulin (10 IU/kg/day; S.C.). All treatments were started immediately following confirmation of diabetes in diabetic groups and were continued for eight weeks. Behavioral functions were evaluated by employing standard behavioral paradigms. Additionally, oxidative status and neuronal viability were assessed in the hippocampus. The results of behavioral tests showed that diabetes enhanced anxiety/depression-like behaviors, reduced exploratory and locomotor activities, decreased memory performance, and increased stress related behaviors. These changes in diabetic rats were accompanied by increasing oxidative stress and neuronal loss in the hippocampus. Interestingly, eight weeks of treatment with Aloe vera gel not only alleviated all the mentioned deficits related to diabetes, but in some aspects, it was even more effective than insulin. In conclusion, the results suggest that both interrelated hypoglycemic and antioxidative properties of Aloe vera gel are possible mechanisms that improve behavioral deficits and protect hippocampal neurons in diabetic animals. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  18. A novel green nonaqueous sol-gel process for preparation of partially stabilized zirconia nanopowder

    Directory of Open Access Journals (Sweden)

    Guo Feng

    2017-09-01

    Full Text Available A novel green nonaqueous sol-gel process was developed to prepare 3 mol% Y2O3-doped ZrO2 nanopowder from zirconium oxychloride and without need for washing of the obtained particles. It was shown that highly dispersive nanometer-scale zirconia powder with the particle size of 15–25 nm and BET surface area of 41.2 m2/g can be prepared. The sintering behaviour was also investigated. Density of the translucent body sintered at 1400 °C is 98.7 ± 0.3% of its theoretical density and the surface and cross section areas are dense without holes or other defects. The bending strength of the sintered sample is 928 ± 64 MPa.

  19. Properties of Zn O/Cr thin films prepared by Sol-Gel

    International Nuclear Information System (INIS)

    Tirado G, S.; Olvera A, R.

    2014-08-01

    Zn O films and those superficially modified with chromium were deposited on substrates of soda-lime glass, using the Sol-Gel process and the repeated immersion method. Starting from dehydrated zinc acetate was prepared a solution to 0.6 M to ambient temperature in 2-methoxyethanol and monoethanolamine (Mea) stirring magnetically. The Sol was prepared with an aging to seven days and was used to grow a films group with thickness to eight immersions. These same films were superficially modified with several depositions of a chromium nitrate Sol dissolved in ethanol to low concentration. The Zn O films were structurally characterized by X-ray diffraction, its chemical composition by energy dispersive X-ray spectroscopy and its morphology by scanning electron microscopy and atomic force microscopy, as well as their optical properties by UV-vis. Of the obtained results are proposed possible applications. (author)

  20. The Preparation and Property of Graphene /Tin Oxide Transparent Conductive Film

    Directory of Open Access Journals (Sweden)

    SUN Tao

    2017-02-01

    Full Text Available Graphene doped tin oxide composites were prepared with SnCIZ·2HZ 0 and graphene oxide as raw materials with sol-gel method and then spincoated on the quartz glass to manufacture a new transparent conductive film. The composite film was characterized with X-ray diffraction(XRDand scanning electron microscopy(SEM analysis. XRD results show that the graphene oxide was successfully prepared with Hummers method. The graphene layers and particulate SnOZ can be clearly observed in SEM photos. The transmittance and conductivity of the thin films were tested with ultraviolet visible spectrophotometer and Hall effect measurement. The results show that the transmittivity of composite film in visible region is more than 90% and surface square resistance is 41 S2/口.The graphene/ SnOZ film exhibits a higher performance in transparence and conductivity than commercial FTO glass.

  1. Antimicrobial Activity of Thin Solid Films of Silver Doped Hydroxyapatite Prepared by Sol-Gel Method

    Science.gov (United States)

    Iconaru, Simona Liliana; Chapon, Patrick; Le Coustumer, Philippe; Predoi, Daniela

    2014-01-01

    In this work, the preparation and characterization of silver doped hydroxyapatite thin films were reported and their antimicrobial activity was characterized. Silver doped hydroxyapatite (Ag:HAp) thin films coatings substrate was prepared on commercially pure Si disks by sol-gel method. The silver doped hydroxyapatite thin films were characterized by various techniques such as Scanning electron microscopy (SEM) with energy Dispersive X-ray attachment (X-EDS), Fourier transform infrared spectroscopy (FT-IR), and glow discharge optical emission spectroscopy (GDOES). These techniques have permitted the structural and chemical characterisation of the silver doped hydroxyapatite thin films. The antimicrobial effect of the Ag:HAp thin films on Escherichia coli and Staphylococcus aureus bacteria was then investigated. This is the first study on the antimicrobial effect of Ag:HAp thin films obtained by sol-gel method. The results of this study have shown that the Ag:HAp thin films with x Ag = 0.5 are effective against E. coli and S. aureus after 24 h. PMID:24523630

  2. Antimicrobial activity of thin solid films of silver doped hydroxyapatite prepared by sol-gel method.

    Science.gov (United States)

    Iconaru, Simona Liliana; Chapon, Patrick; Le Coustumer, Philippe; Predoi, Daniela

    2014-01-01

    In this work, the preparation and characterization of silver doped hydroxyapatite thin films were reported and their antimicrobial activity was characterized. Silver doped hydroxyapatite (Ag:HAp) thin films coatings substrate was prepared on commercially pure Si disks by sol-gel method. The silver doped hydroxyapatite thin films were characterized by various techniques such as Scanning electron microscopy (SEM) with energy Dispersive X-ray attachment (X-EDS), Fourier transform infrared spectroscopy (FT-IR), and glow discharge optical emission spectroscopy (GDOES). These techniques have permitted the structural and chemical characterisation of the silver doped hydroxyapatite thin films. The antimicrobial effect of the Ag:HAp thin films on Escherichia coli and Staphylococcus aureus bacteria was then investigated. This is the first study on the antimicrobial effect of Ag:HAp thin films obtained by sol-gel method. The results of this study have shown that the Ag:HAp thin films with x(Ag) = 0.5 are effective against E. coli and S. aureus after 24 h.

  3. Antimicrobial Activity of Thin Solid Films of Silver Doped Hydroxyapatite Prepared by Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    Simona Liliana Iconaru

    2014-01-01

    Full Text Available In this work, the preparation and characterization of silver doped hydroxyapatite thin films were reported and their antimicrobial activity was characterized. Silver doped hydroxyapatite (Ag:HAp thin films coatings substrate was prepared on commercially pure Si disks by sol-gel method. The silver doped hydroxyapatite thin films were characterized by various techniques such as Scanning electron microscopy (SEM with energy Dispersive X-ray attachment (X-EDS, Fourier transform infrared spectroscopy (FT-IR, and glow discharge optical emission spectroscopy (GDOES. These techniques have permitted the structural and chemical characterisation of the silver doped hydroxyapatite thin films. The antimicrobial effect of the Ag:HAp thin films on Escherichia coli and Staphylococcus aureus bacteria was then investigated. This is the first study on the antimicrobial effect of Ag:HAp thin films obtained by sol-gel method. The results of this study have shown that the Ag:HAp thin films with xAg=0.5 are effective against E. coli and S. aureus after 24 h.

  4. Preparation of mesoporous silica microparticles by sol-gel/emulsion route for protein release.

    Science.gov (United States)

    Vlasenkova, Mariya I; Dolinina, Ekaterina S; Parfenyuk, Elena V

    2018-04-06

    Encapsulation of therapeutic proteins into particles from appropriate material can improve both stability and delivery of the drugs, and the obtained particles can serve as a platform for development of their new oral formulations. The main goal of this work was development of sol-gel/emulsion method for preparation of silica microcapsules capable of controlled release of encapsulated protein without loss of its native structure. For this purpose, the reported in literature direct sol-gel/W/O/W emulsion method of protein encapsulation was used with some modifications, because the original method did not allow to prepare silica microcapsules capable for protein release. The particles were synthesized using sodium silicate and tetraethoxysilane as silica precursors and different compositions of oil phase. In vitro kinetics of bovine serum albumin (BSA) release in buffer (pH 7.4) was studied by Fourier transform infrared (FTIR) and fluorescence spectrometry, respectively. Structural state of encapsulated BSA and after release was evaluated. It was found that the synthesis conditions influenced substantially the porous structure of the unloaded silica particles, release properties of the BSA-loaded silica particles and structural state of the encapsulated and released protein. The modified synthesis conditions made it possible to obtain the silica particles capable of controlled release of the protein during a week without loss of the protein native structure.

  5. Preparation and characterization of strontium-fluorapatite nanopowders by sol-gel method

    Science.gov (United States)

    Kamaei, Maryam; Fathi, Mohammad Hossein

    2018-01-01

    Biomaterials based on calcium orthophosphate are especially attractive for use in medicine, for bone and teeth implants due to their biological properties, such as biocompatibility and bioactivity. Among them, hydroxyapatite (HAP; Ca10(PO4)6(OH)2) is used particularly because of its similarities to the inorganic component of bone. Hydroxyapatite has been widely used for biomedical applications. Despite desirable properties such as bioactivity, biocompatibility, solubility and adsorption, synthetic HA is limited in application due to poor thermostability and poor mechanical properties. Properties of HA can be tailored over a wide range by incorporating different ions into HA lattice. Use of the sol-gel technique is technically simple, cost effective and beneficial for fabrication biomaterials. This research aimed to prepare and characterize Sr-doped FA nanopowders (Sr-FA). Sr-FA with different Sr contents was prepared by sol-gel method. The designated degree of substitution of Ca by Sr in the mixture was determined by the x value in the general formula of (Ca10-x Srx(PO4)6F2), where x=0,0.5,1. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) techniques were utilized to characterize the obtained nano powders. Results showed that Sr ions entered into the fluorapatite lattice and occupied Ca sites. The incorporation of Sr ions into the fluorapatite resulted in the increase of the lattice parameters.

  6. Performance study of molybdenum gels with titanium for preparation of 99Mo-99mTc generators

    International Nuclear Information System (INIS)

    Moraes, Vanessa; Osso Junior, Joao Alberto

    2005-01-01

    99m Tc is the most used radioisotope in Nuclear Medicine, due to nuclear characteristics. It is obtained by the radioactive decay of 99 Mo, generator of radioisotope system. When 99 Mo is produced by the activation in reactor, the most used technique for the preparation of the generators is the gel type generator, which incorporates 99 Mo to the gel that is insoluble, chemically inert to the solutions and with properties of ion exchange. Several countries had already studied this methodology, as is the case of Vietnam, India, China, Australian. This work has the objective of studying the performance and characterization of molybdenum gels with titanium. Four variables in the preparation of the gel were studied: mass ratio between Mo and Ti (1.80 and 2.25), concentration of NaOH (2 and 4 mol/L), final temperature (25 and 50 deg C) and pH (3.5 and 4.5). The prepared gels were analyzed with relation to the size of its particles, identification of its structure, amount of molybdenum, amount of titanium, profile of elution, pH of the elution, determination of the radioisotopes in the eluate and final radiochemical purity. The final result is a formularization of the gel with the best characteristics for posterior preparation of the generator of 99m Tc- 99 Mo. (author)

  7. A sol-gel method to synthesize indium tin oxide nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Xiuhua Li; Xiujuan xu; Xin Yin; Chunzhong Li; Jianrong Zhang

    2011-01-01

    Transparent conductive indium tin oxide (ITO) nanoparticles were synthesized by a novel sol-gel method.Granulated indium and tin were dissolved in HNO3 and partially complexed with citric acid.A sol-gel process was induced when tertiary butyl alcohol was added dropwise to the above solution.ITO nanoparticles with an average crystallite size of 18.5 nm and surface area of 32.6 m2/g were obtained after the gel was heat-treated at 700 C.The ITO nanoparticles showed good sinterability,the starting sintering temperature decreased sharply to 900 C,and the 1400 C sintered pellet had a density of 98.1 % of theoretical density (TD).

  8. How do monomeric components of a polymer gel dosimeter respond to ionising radiation: A steady-state radiolysis towards preparation of a 3D polymer gel dosimeter

    International Nuclear Information System (INIS)

    Kozicki, Marek

    2011-01-01

    Ionising radiation-induced reactions of aqueous single monomer solutions and mixtures of poly(ethylene glycol) diacrylate (PEGDA) and N,N'-methylenebisacrylamide (Bis) in a steady-state condition are presented below and above gelation doses in order to highlight reactions in irradiated 3D polymer gel dosimeters, which are assigned for radiotherapy dosimetry. Both monomers are shown to undergo radical polymerisation and cross-linking, which result in the measured increase in molecular weight and radius of gyration of the formed polydisperse polymer coils. The formation of nanogels was also observed for Bis solutions at a low concentration. In the case of PEGDA-Bis mixtures, co-polymerisation is suggested as well. At a sufficiently high radiation dose, the formation of a polymer network was observed for both monomers and their mixture. For this reason a sol-gel analysis for PEGDA and Bis was performed gravimetrically and a proposition of an alternative to this method employing a nuclear magnetic resonance technique is made. The two monomers were used for preparation of 3D polymer gel dosimeters having the acronyms PABIG and PABIG nx . The latter is presented for the first time in this work and is a type of the formerly established PABIG polymer gel dosimeter. The elementary characteristics of the new composition are presented, underlining the ease of its preparation, low dose threshold, and slightly increased sensitivity but lower quasi-linear range of dose response in comparison to PABIG. - Highlights: → Steady-state radiolysis of Bis, PEGDA and Bis-PEGDA is examined. → High Mw products are formed at low absorbed doses. → Formation of Bis nanogels is likely; PEGDA solutions form hydrogels. → NMR technique can be used for sol-gel analysis. → Features of 3D polymer gel dosimeters made from PEGDA and Bis are shown.

  9. Cobalt(II phthalocyanine bonded to 3-n-propylimidazole immobilized on silica gel surface: preparation and electrochemical properties

    Directory of Open Access Journals (Sweden)

    Fujiwara Sergio T.

    1999-01-01

    Full Text Available Co-Phthalocyanine complex was immobilized on 3-n-propylimidazole groups grafted on a porous SiO2 surface (specific surface area S BET = 500 m² g-1 and efficiently electrocatalyzed the oxalic acid oxidation on a carbon paste electrode surface made of this material. Intermolecular interactions of the complex species which can normally interfere in the redox process practically are not observed in the present case because of a low average surface density, delta = 4.7 x 10-13 mol cm-2 (delta = Nf/S BET, where Nf is the amount of adsorbed Co-phtalocyanine per gram of modified silica gel of the complex species material prepared. The linear response of the electrode to oxalic acid concentration, between 6.5 x 10-4 and 3.2 x 10-3 mol L-1, associated with its high chemical stability makes the covalently immobilized Co-phtalocyanine complex material very attractive in preparing a new class of chemical sensors.

  10. Structural and optical studies of nano-structure silica gel doped with different rare earth elements, prepared by two different sol -gel techniques

    International Nuclear Information System (INIS)

    Battisha, I.K.; El Beyally, A.; Seliman, S.I.; El Nahrawi, A.S.

    2005-01-01

    Structural and optical characteristics of pure silica gel (silica-xerogel, SiO 2 ) and doped with different concentrations ranging from 1 up to 6% of some rare earth (REEs) ions such as, praseodymium Pr +3 ,and Europium Eu +3 , Erbium Er +3 and Holmium Ho +3 , ions, in the form of thin film and monolith materials were prepared by sol - gel technique, Using tetra-ethoxysilane as precursor materials, which are of particular interest for sol-gel integrated optics applications. Some structural and optical features of sol-gel derived monolith and thin films are analyzed and compared, namely the structure of nano-particle monolith and thin film silica-gel samples, based on X-ray diffraction (XRD). The types of structural information obtainable are compared in detail. It is show that the XRD spectra of a-cristobalite are obtained for the two type materials and even by doping with the four REEs ions. Optical measurements of monolith and thin films were also studied and compared, the normal transmission and specular reflection were measured. The refractive index were calculated and discussed

  11. Preparation of demipermanent and semipermanent hair dyes gels from ethanol extract of Caesalpinia sappan L. using carbomer as gelling agent

    Science.gov (United States)

    Indrawati, T.; Syahrin, A.; Irpan

    2017-07-01

    Caesalpinia sappan L. (Cs L) contains of essential oils, saponin, brazilin, brazilein, alkaloids, flavonoids and tannins that have a function as cationic natural dyes. The aim of this research was to prepare the ethanol extract of Cs L wood and to prepare demi-permanent and semi-permanent of hair dye gels by using Carbomer of 2 % and 1.5 % as gelling agent and Cs L extract as cationic dyes. The Extract of Cs L was macerated by using ethanol of 96 % as the solvent, and then thickened. Three formula of demi-permanent hair dye gels were made by using Cs L extract of 3 %, 6% and 9 %. Three formula of semi-permanent hair dye gels were made by using Cs L extract of 2.50 %, 7.00 % and 10.50 %. Those hair dyes gels were prepared by swelling and mixing methods. All products of hair dyes gels were evaluated with organoleptic test, homogeneity test, pH test, consistency test, rheological properties test and dyeing effect test. The demi-permanent hair dye gels products had brown to brown dark black colors, pH of 5.05-5.43, homogeny, specific Cs L odor, and had pseudoplastic thixotropic flow characteristic. The semi-permanent hair dye gels products had red color pH of 6.5-6.25, homogeny, Cs L odor, and have pseudoplastic thixotropic flow characteristics. The optimum formula of demi-permanent was formula gel that contained of 6 % extract of Cs L and the optimum formula of permanent hair dyes gel was formula that contained of 10.50 % extract of Cs L.

  12. Improvement of physical properties of IGZO thin films prepared by excimer laser annealing of sol–gel derived precursor films

    Energy Technology Data Exchange (ETDEWEB)

    Tsay, Chien-Yie, E-mail: cytsay@fcu.edu.tw; Huang, Tzu-Teng

    2013-06-15

    Indium gallium zinc oxide (IGZO) transparent semiconductor thin films were prepared by KrF excimer laser annealing of sol–gel derived precursor films. Each as-coated film was dried at 150 °C in air and then annealed using excimer laser irradiation. The influence of laser irradiation energy density on surface conditions, optical transmittances, and electrical properties of laser annealed IGZO thin films were investigated, and the physical properties of the excimer laser annealed (ELA) and the thermally annealed (TA) thin films were compared. Experimental results showed that two kinds of surface morphology resulted from excimer laser annealing. Irradiation with a lower energy density (≤250 mJ cm{sup −2}) produced wavy and irregular surfaces, while irradiation with a higher energy density (≥350 mJ cm{sup −2}) produced flat and dense surfaces consisting of uniform nano-sized amorphous particles. The explanation for the differences in surface features and film quality is that using laser irradiation energy to form IGZO thin films improves the film density and removes organic constituents. The dried IGZO sol–gel films irradiated with a laser energy density of 350 mJ/cm{sup 2} had the best physical properties of all the ELA IGZO thin films. The mean resistivity of the ELA 350 thin films (4.48 × 10{sup 3} Ω cm) was lower than that of TA thin films (1.39 × 10{sup 4} Ω cm), and the average optical transmittance in the visible range (90.2%) of the ELA 350 thin films was slightly higher than that of TA thin films (89.7%). - Highlights: • IGZO semiconductor films were prepared by laser annealing of sol–gel derived films. • Surface roughness and resistivity of ELA samples were affected by energy density. • The ELA 350 IGZO film exhibited the best properties among all of ELA IGZO films. • Transmittance and resistivity of ELA 350 films are greater than those of TA films.

  13. Oxidative decontamination of chemical and biological warfare agents using L-Gel.

    Science.gov (United States)

    Raber, Ellen; McGuire, Raymond

    2002-08-05

    A decontamination method has been developed using a single reagent that is effective both against chemical warfare (CW) and biological warfare (BW) agents. The new reagent, "L-Gel", consists of an aqueous solution of a mild commercial oxidizer, Oxone, together with a commercial fumed silica gelling agent, Cab-O-Sil EH-5. L-Gel is non-toxic, environmentally friendly, relatively non-corrosive, maximizes contact time because of its thixotropic nature, clings to walls and ceilings, and does not harm carpets or painted surfaces. The new reagent also addresses the most demanding requirements for decontamination in the civilian sector, including availability, low maintenance, ease of application and deployment by a variety of dispersal mechanisms, minimal training and acceptable expense. Experiments to test the effectiveness of L-Gel were conducted at Lawrence Livermore National Laboratory and independently at four other locations. L-Gel was tested against all classes of chemical warfare agents and against various biological warfare agent surrogates, including spore-forming bacteria and non-virulent strains of real biological agents. Testing showed that L-Gel is as effective against chemical agents and biological materials, including spores, as the best military decontaminants.

  14. Photocatalytic degradation of methylene blue dye by zinc oxide nanoparticles obtained from precipitation and sol-gel methods.

    Science.gov (United States)

    Balcha, Abebe; Yadav, Om Prakash; Dey, Tania

    2016-12-01

    Zinc oxide (ZnO) nanoparticles were synthesized by precipitation and sol-gel methods. The aim of this study was to understand how different synthetic methods can affect the photocatalytic activity of ZnO nanoparticles. As-synthesized ZnO nanoparticles were characterized by X-ray diffraction (XRD) and UV-Visible spectroscopic techniques. XRD patterns of ZnO powders synthesized by precipitation and sol-gel methods revealed their hexagonal wurtzite structure with crystallite sizes of 30 and 28 nm, respectively. Their photocatalytic activities were evaluated by photocatalytic degradation of methylene blue, a common water pollutant, under UV radiation. The effects of operational parameters such as photocatalyst load and initial concentration of the dye on photocatalytic degradation of methylene blue were investigated. While the degradation of dye decreased over the studied dye concentration range of 20 to 100 mg/L, an optimum photocatalyst load of 250 mg/L was needed to achieve dye degradation as high as 81 and 92.5 % for ZnO prepared by precipitation and sol-gel methods, respectively. Assuming pseudo first-order reaction kinetics, this corresponded to rate constants of 8.4 × 10 -3 and 12.4 × 10 -3  min -1 , respectively. Hence, sol-gel method is preferred over precipitation method in order to achieve higher photocatalytic activity of ZnO nanostructures. Photocatalytic activity is further augmented by better choice of capping ligand for colloidal stabilization, starch being more effective than polyethylene glycol (PEG).

  15. Boron cross-linked graphene oxide/polyvinyl alcohol nanocomposite gel electrolyte for flexible solid-state electric double layer capacitor with high performance

    International Nuclear Information System (INIS)

    Huang, Yi-Fu; Wu, Peng-Fei; Zhang, Ming-Qiu; Ruan, Wen-Hong; Giannelis, Emmanuel P.

    2014-01-01

    Highlights: • Gel electrolyte is prepared and used in electric double layer capacitor. • Insertion of boron crosslinks into GO agglomerates opens channels for ion migration. • Solid supercapacitors show excellent specific capacitance and cycle stability. • Nanocomposite electrolyte shows better thermal stability and mechanical properties. - Abstract: A new family of boron cross-linked graphene oxide/polyvinyl alcohol (GO-B-PVA) nanocomposite gels is prepared by freeze-thaw/boron cross-linking method. Then the gel electrolytes saturated with KOH solution are assembled into electric double layer capacitors (EDLCs). Structure, thermal and mechanical properties of GO-B-PVA are explored. The electrochemical properties of EDLCs using GO-B-PVA/KOH are investigated, and compared with those using GO-PVA/KOH gel or KOH solution electrolyte. FTIR shows that boron cross-links are introduced into GO-PVA, while the boronic structure inserted into agglomerated GO sheets is demonstrated by DMA analysis. The synergy effect of the GO and the boron crosslinking benefits for ionic conductivity due to unblocking ion channels, and for improvement of thermal stability and mechanical properties of the electrolytes. Higher specific capacitance and better cycle stability of EDLCs are obtained by using the GO-B-PVA/KOH electrolyte, especially the one at higher GO content. The nanocomposite gel electrolytes with excellent electrochemical properties and solid-like character are candidates for the industrial application in high-performance flexible solid-state EDLCs

  16. Oxidation catalysts and process for preparing same

    International Nuclear Information System (INIS)

    1980-01-01

    Compounds particularly suitable as oxidation catalysis are described, comprising specified amounts of uranium, antimony and tin as oxides. Processes for making and using the catalysts are described. (U.K.)

  17. Non-traditional Oxidants in Preparative Coordination Chemistry

    Science.gov (United States)

    Kukushkin, Vadim Yu; Kukushkin, Yurii N.

    1986-10-01

    The application of nitrosonium and arenediazonium salts, carbenium, silver(I), and mercury(II) ions, protic acids, and amine oxides as oxidants in preparative coordination chemistry is examined. Specific examples illustrate which problems in the field of the synthesis and reactions of coordination compounds can be solved with the aid of these oxidants. The bibliography includes 158 references.

  18. Study of alumosilicate porcelains: Sol-gel preparation, characterization and erosion evaluated by gravimetric method

    International Nuclear Information System (INIS)

    Bogdanoviciene, Irma; Jankeviciute, Audrone; Pinkas, Jiri; Beganskiene, Aldona; Kareiva, Aivaras

    2008-01-01

    In this paper, the sol-gel synthesis and characteristic properties of kalsilite-type alumosilicates (KAlSiO 4 and K 0.5 Na 0.5 AlSiO 4 ) are reported. The polycrystalline powders were characterized by thermal analysis (TG/DTA), powder X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). Single-phase kalsilite oxides have been obtained after annealing precursor gels for 5 h in the temperature range of 750-850 deg. C. It was demonstrated that crystallinity of the samples slightly depends on the temperature of annealing. From the results obtained, it could be concluded that the KAlSiO 4 solids are composed of the volumetric plate-like grains with no regular size (from 5 μm to 30 μm at 750 deg. C and around 5-50 μm at 850 deg. C). Larger crystallites for mixed potassium-sodium kalsilite have formed (from 10 μm to 80 μm at 750 deg. C and >100 μm at 850 deg. C) in comparison with potassium kalsilite samples). The erosion of obtained dental porcelain samples stored in saliva, beer and Coca-Cola was compared

  19. Preparation and characterization of ZnO transparent semiconductor thin films by sol-gel method

    International Nuclear Information System (INIS)

    Tsay, Chien-Yie; Fan, Kai-Shiung; Chen, Sih-Han; Tsai, Chia-Hao

    2010-01-01

    Transparent semiconductor thin films of zinc oxide (ZnO) were deposited onto alkali-free glass substrates by the sol-gel method and spin-coating technique. In this study, authors investigate the influence of the heating rate of the preheating process (4 or 10 o C/min) on the crystallization, surface morphology, and optical properties of sol-gel derived ZnO thin films. The ZnO sol was synthesized by dissolving zinc acetate dehydrate in ethanol, and then adding monoethanolamine. The as-coated films were preheated at 300 o C for 10 min and annealed at 500 o C for 1 h in air ambiance. Experimental results indicate that the heating rate of the preheating process strongly affected the surface morphology and transparency of ZnO thin film. Specifically, a heating rate of 10 o C/min for the preheating process produces a preferred orientation along the (0 0 2) plane and a high transmittance of 92% at a wavelength of 550 nm. Furthermore, this study reports the fabrication of thin-film transistors (TFTs) with a transparent ZnO active channel layer and evaluates their electrical performance.

  20. Photocatalytic Activity in CH3CN Related to the Surface Properties of TiO2 Powders Prepared by Sol-Gel Method

    OpenAIRE

    Bettoni, Marta; Candori, Pietro; Marmottini, Fabio; Perenze, Nicoletta; Rol, Cesare; Sebastiani, Giovanni V.; Vecchiocattivi, Franco

    2009-01-01

    Some TiO2 powders, prepared from titanium(IV)tetraisopropoxide by the sol-gel method and thermally treated between 100 and 1000∘C, have been characterized by X-ray powder diffraction and by nitrogen adsorption and desorption at 77 K to calculate the BET-specific surface area, from which the micropore volume and the external surface area can be derived. The photocatalytic activity (ka) of the above powders has been evaluated considering the TiO2-sensitized photo-oxidation of 4-methoxybenzyl al...

  1. Application of gel-Co-conversion for TRU (Pu, Np, Am) fuel and target preparation

    International Nuclear Information System (INIS)

    Prunier, C.; Warin, D.; Bauer, M.

    1993-01-01

    In the fabrication of fuel containing transuranium (TRU) elements, flow sheets and techniques which allow a shielded and/or remote fabrication will probably need to be applied. One approach, which has been demonstrated on the laboratory and semi prototype scale, is the wet fabrication route of coprecipitation of the matrix element uranium mixed with plutonium to form dense spherical particles or to produce hybrid pellets made from pressed gel microspheres. The ceramic material produced holds the TRU-elements homogeneously distributed in the matrix. In conjunction with the Departement d'Etudes des Combustibles of the French Commissariat a l'Energie Atomique (CEA-DEC) in Cadarache, the Paul Scherrer Institut (PSI) in Switzerland is further developing a mixed nitride ceramic and mixed oxide with high concentrations (up to 50%) of plutonium with the aim of a joint irradiation test of transuranium elements in the French PHENIX reactor. 6 refs., 3 figs., 3 tabs

  2. Vanadium oxide thin films and fibers obtained by acetylacetonate sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Berezina, O.; Kirienko, D. [Department of Physical Engineering, Petrozavodsk State University, 185910 Petrozavodsk (Russian Federation); Pergament, A., E-mail: aperg@psu.karelia.ru [Department of Physical Engineering, Petrozavodsk State University, 185910 Petrozavodsk (Russian Federation); Stefanovich, G.; Velichko, A. [Department of Physical Engineering, Petrozavodsk State University, 185910 Petrozavodsk (Russian Federation); Zlomanov, V. [Department of Chemistry, Moscow State University, 119991 Moscow (Russian Federation)

    2015-01-01

    Vanadium oxide films and fibers have been fabricated by the acetylacetonate sol–gel method followed by annealing in wet nitrogen. The samples are characterized by X-ray diffraction and electrical conductivity measurements. The effects of a sol aging, the precursor decomposition and the gas atmosphere composition on the annealing process, structure and properties of the films are discussed. The two-stage temperature regime of annealing of amorphous films in wet nitrogen for formation of the well crystallized VO{sub 2} phase is chosen: 1) 25–550 °C and 2) 550–600 °C. The obtained films demonstrate the metal–insulator transition and electrical switching. Also, the effect of the polyvinylpyrrolidone additive concentration and electrospinning parameters on qualitative (absence of defects and gel drops) and quantitative (length and diameter) characteristics of vanadium oxide fibers is studied. - Highlights: • Vanadium oxide thin films and fibers are synthesized by sol–gel method. • The effect of annealing, atmosphere, time and electrospinning parameters is studied. • Produced VO{sub 2} structures exhibit metal–insulator transition and electrical switching.

  3. Controlled formation of emulsion gels stabilized by salted myofibrillar protein under malondialdehyde (MDA)-induced oxidative stress.

    Science.gov (United States)

    Zhou, Feibai; Sun, Weizheng; Zhao, Mouming

    2015-04-15

    This study presented the cold-set gelation of emulsions stabilized by salted myofibrillar protein (MP) under oxidative stress originated from malondialdehyde (MDA). Gel properties were compared over a range of MDA/NaCl concentrations including gel viscoelastic properties, strength, water-holding capacity (WHC), amount of protein entrapped, and microstructure. The oxidative stability of emulsion gels as indicated by lipid hydroperoxide was further determined and compared. Results indicated that emulsion stabilized by MP at swollen state under certain ionic strengths (0.2-0.6 M) was the premise of gel formation under MDA. In the presence of intermediate MDA concentrations (2.5-10 mM), the emulsion gels showed an improved elasticity, strength, WHC, and oxidative stability. This improvement should be mainly attributed to the enhanced protein-protein cross-linkings via MDA, which were homogeneously formed among absorbed and/or unabsorbed proteins, entrapping a greater amount and fractions of protein within network. Therefore, the oil droplets were better adherent to the gel matrix. Nevertheless, addition of high MDA concentrations (25-50 mM) led to the formation of excessive covalent bonds, which might break protein-protein bonds and trigger the desorption of protein from the interface. This ultimately caused "oil leak" phenomena as well as the collapse of gel structure and, thus, overall decreased gel properties and oxidative stability.

  4. Highly concentrated EDTA gel improves cleaning efficiency of root canal preparation in vitro.

    Science.gov (United States)

    Putzer, P; Hoy, L; Günay, H

    2008-12-01

    Debris and smear layer, as a product of mechanical root canal instrumentation, reduce the effectiveness of pharmacological substances to prevent post-treatment diseases and impair direct contact of filling materials with a clean dentinal surface. The aim of this in vitro study was to investigate the presence and localization of debris and smear layer via scanning electron microscope analysis after standardized root canal preparation with different chelating agents. Dentin surfaces received treatment with: (1) 15% ethylenediaminetetraacetic acid (EDTA), (2) 18.6% EDTA (3) and 24% EDTA or without any demineralizing chemicals as control. Forty vertically split human premolars were sputtered and divided into coronal, middle, and apical sections, followed by a randomized, blinded score evaluation using five scores. Pairwise comparisons of all treatment groups against a control group have been performed by Mann-Whitney U test and the Kruskal-Wallis test. Debris grades showed no significant difference between the three regions of the root canals, except for 18.6% EDTA in the central third. Smear layer and smear plug removal was concentration-dependent. Removal of the smear layer in the three areas showed that there was a statistically significant difference between all parts when using 18.6% and 24% EDTA concentrations compared with the control. The best smear layer removal in the apical region was observed using a 24% EDTA gel as chelating agent and lubricant. The usage of EDTA gel >/=18.6% presented a better cleaning regime when compared to the control group.

  5. Effect of urea on the photoactivity of titania powder prepared by sol-gel method

    International Nuclear Information System (INIS)

    Cheng Ping; Deng Changsheng; Gu Mingyuan; Dai Xiaming

    2008-01-01

    The synthesis of nanocrystalline titania powders from the hydrolysis of Ti(OBu n ) 4 in the presence of urea was investigated. DRS results showed that a redshift occurred in the absorption edge of titania with increasing the content of urea. XRD results indicated that urea showed a retarding effect on the transformation of titania from anatase to rutile. Moreover, the addition of urea resulted in a higher Brunauer-Emmett-Teller (BET) surface area as well as a larger average pore size of TiO 2 nanoparticles. The average pore size of urea/TiO 2 gels calcined at 500 deg. C increased with the increase of urea content, while the specific surface area increased with the amount of urea to reach a maximum at 10% and then decreased with further increase of the amount of urea. The maximal specific surface area of 64.4 m 2 g -1 was obtained for 10% urea/TiO 2 gels calcined at 500 deg. C, which showed an average particle size of 15 nm and pore size distribution in the range of mesopores centered at 5.8 nm. The photocatalytic experiments exhibited that titania nanoparticles prepared in the presence of urea could effectively photodegrade methyl orange under visible light irradiation due to the redshift of the absorption edge. The maximum photoactivity was achieved when the content of urea was 10%, which was attributed to the higher specific surface area

  6. Sol-gel Process in Preparation of Organic-inorganic Hybrid Materials

    Directory of Open Access Journals (Sweden)

    Macan, J

    2008-07-01

    Full Text Available Organic-inorganic hybrid materials are a sort of nanostructured material in which the organic and inorganic phases are mixed at molecular level. The inorganic phase in hybrid materials is formed by the sol-gel process, which consists of reactions of hydrolysis and condensation of metal (usually silicon alkoxides. Flexibility of sol-gel process enables creation of hybrid materials with varying organic and inorganic phases in different ratios, and consequently fine-tuning of their properties. In order to obtain true hybrid materials, contact between the phases should be at molecular level, so phase separation between thermodynamically incompatible organic and inorganic phases has to be prevented. Phase interaction can be improved by formation of hydrogen or covalent bonds between them during preparation of hybrid materials. Covalent bond can be introduced by organically modified silicon alkoxides containing a reactive organic group (substituent capable of reacting with the organic phase. In order to obtain hybrid materials with desired structures, a detailed knowledge of hydrolysis and condensation mechanism is necessary. The choice of catalyst, whether acid or base, has the most significant influence on the structure of the inorganic phase. Other important parameters are alkoxide concentration, water: alkoxide ratio, type of alkoxide groups, solvent used, temperature, purity of chemicals used, etc. Hydrolysis and condensation of organically modified silicon alkoxides are additionally influenced by nature and size of the organic supstituent.

  7. Nanostructured zirconium titanate fibers prepared by particulate sol–gel and cellulose templating techniques

    Energy Technology Data Exchange (ETDEWEB)

    Rouhani, P. [Helmerich Advanced Technology Research Center, School of Electrical and Computer Engineering, Oklahoma State University, OK 74106 (United States); Salahinejad, E. [Helmerich Advanced Technology Research Center, School of Material Science and Engineering, Oklahoma State University, OK 74106 (United States); Department of Materials Science and Engineering, School of Engineering, Shiraz University, Zand Blvd., 7134851154 Shiraz (Iran, Islamic Republic of); Kaul, R. [Department of Biochemistry and Microbiology, Center for Health Sciences, Oklahoma State University, OK 74107 (United States); Vashaee, D. [Helmerich Advanced Technology Research Center, School of Electrical and Computer Engineering, Oklahoma State University, OK 74106 (United States); Tayebi, L., E-mail: lobat.tayebi@okstate.edu [Helmerich Advanced Technology Research Center, School of Material Science and Engineering, Oklahoma State University, OK 74106 (United States); School of Chemical Engineering, Oklahoma State University, Stillwater, OK 74078 (United States)

    2013-08-15

    Highlights: •A method to produce zirconium titanate fibers was introduced. •The resultant structure and photocatalytic activity of the fiber were investigated. •The fiber exhibited higher photocatalytic characteristics, compared with the powders. -- Abstract: In this paper, a method for cost-effective production of nanostructured zirconium titanate (ZrTiO{sub 4}) fibers is introduced. In this method, ZrTiO{sub 4} fibers were synthesized by a sol–gel technique using cellulose fibers as the template. The resultant structures were studied by transmission electron microscopy, X-ray diffraction, scanning electron microscopy, and Brunauer–Emmett–Teller (BET) analyses. The photocatalytic activity of the fiber was compared to that of ZrTiO{sub 4} powders prepared by the same sol–gel method, in dark and under UVA and UVC radiations. According to the results, after calcination accompanied by the template removal, the ZrTiO{sub 4} fiber consists of uniformly-deposited, crystalline nanoparticles. This nanostructured fiber exhibited a higher surface area and a higher porosity compared with the ZrTiO{sub 4} powders, resulting in considerably higher photocatalytic characteristics, as confirmed by the experiment. The large surface area and the enhanced photocatalytic activity of the ZrTiO{sub 4} fibers also offer applications in sensors and bioactive films.

  8. Benchmarking sample preparation/digestion protocols reveals tube-gel being a fast and repeatable method for quantitative proteomics.

    Science.gov (United States)

    Muller, Leslie; Fornecker, Luc; Van Dorsselaer, Alain; Cianférani, Sarah; Carapito, Christine

    2016-12-01

    Sample preparation, typically by in-solution or in-gel approaches, has a strong influence on the accuracy and robustness of quantitative proteomics workflows. The major benefit of in-gel procedures is their compatibility with detergents (such as SDS) for protein solubilization. However, SDS-PAGE is a time-consuming approach. Tube-gel (TG) preparation circumvents this drawback as it involves directly trapping the sample in a polyacrylamide gel matrix without electrophoresis. We report here the first global label-free quantitative comparison between TG, stacking gel (SG), and basic liquid digestion (LD). A series of UPS1 standard mixtures (at 0.5, 1, 2.5, 5, 10, and 25 fmol) were spiked in a complex yeast lysate background. TG preparation allowed more yeast proteins to be identified than did the SG and LD approaches, with mean numbers of 1979, 1788, and 1323 proteins identified, respectively. Furthermore, the TG method proved equivalent to SG and superior to LD in terms of the repeatability of the subsequent experiments, with mean CV for yeast protein label-free quantifications of 7, 9, and 10%. Finally, known variant UPS1 proteins were successfully detected in the TG-prepared sample within a complex background with high sensitivity. All the data from this study are accessible on ProteomeXchange (PXD003841). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Effect of thiolated polymers to textural and mucoadhesive properties of vaginal gel formulations prepared with polycarbophil and chitosan.

    Science.gov (United States)

    Cevher, Erdal; Sensoy, Demet; Taha, Mohamed A M; Araman, Ahmet

    2008-01-01

    The aim of this study was to design and evaluate of mucoadhesive gel formulations for the vaginal application of clomiphene citrate (CLM) for local treatment of human papilloma virus (HPV) infections. Chitosan (CHI) and polycarbophil (PC) were covalently modified using the thioglycolic acid and L-cysteine, respectively. The formation of thiol conjugates of chitosan (CHI-TG) and polycarbophil (PC-CYS) were confirmed by FT-IR analysis and PC-CYS and CHI-TG were found to have 148.42 +/- 4.16 and 41.17 +/- 2.34 micromol of thiol groups per gram of polymer, respectively. One percent CLM gels were prepared by combination of various concentrations of PC and CHI with thiolated conjugates of these polymers. Hardness, compressibility, elasticity, adhesiveness and cohesiveness of the gels were measured by Texture profile analysis and the vaginal mucoadhesion was investigated by mucoadhesion test. The increasing in the amount of the thiol conjugates was found to enhance the elasticity, cohesiveness, adhesiveness and mucoadhesion of the gel formulations but not their hardness and compressibility when compared to gels prepared using their respective parent formulations. Slower release rate of CLM from gels was achieved when the polymer concentrations were increased in the gel formulations. PC and its thiol conjugate were found to prolong the release of CLM longer than 70 h unlike gel formulations prepared using CHI and its thiol conjugate which were able to release CLM up to 12 h. Stability of CLM was preserved during the 3 month stability analysis under controlled room temperature and accelerated conditions.

  10. Effects of synthetic parameters on structure and electrochemical performance of spinel lithium manganese oxide by citric acid-assisted sol-gel method

    International Nuclear Information System (INIS)

    Yi Tingfeng; Dai Changsong; Gao Kun; Hu Xinguo

    2006-01-01

    The spinel lithium manganese oxide cathode materials were prepared by citric acid-assisted sol-gel method at 623-1073 K in air. The effects of pH value, raw material, synthesis temperature and time on structure and electrochemical performance of spinel lithium manganese oxide are investigated by X-ray diffraction (XRD), scanning electronic microscope (SEM) and cyclic voltammetry (CV). XRD data results strongly suggest that the synthesis temperature is the dominating factors of the formation of spinel phase, and spinel lithium manganese oxide powder with various crystallites size can be obtained by controlling the sintering time. CV shows that spinel lithium manganese oxide powder formed about 973 K presents the best electrochemical performance with well separated two peaks and the highest peak current. Charge-discharge test indicates that spinel lithium manganese oxide powders calcined at higher temperatures have high discharge capacity and capacity loss, and sintered at lower temperatures has low discharge capacity and high capacity retention

  11. Effects of synthetic parameters on structure and electrochemical performance of spinel lithium manganese oxide by citric acid-assisted sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Yi Tingfeng [Department of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China)]. E-mail: tfyihit@hit.edu.cn; Dai Changsong [Department of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China); Gao Kun [Department of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China); Hu Xinguo [Department of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China)

    2006-11-30

    The spinel lithium manganese oxide cathode materials were prepared by citric acid-assisted sol-gel method at 623-1073 K in air. The effects of pH value, raw material, synthesis temperature and time on structure and electrochemical performance of spinel lithium manganese oxide are investigated by X-ray diffraction (XRD), scanning electronic microscope (SEM) and cyclic voltammetry (CV). XRD data results strongly suggest that the synthesis temperature is the dominating factors of the formation of spinel phase, and spinel lithium manganese oxide powder with various crystallites size can be obtained by controlling the sintering time. CV shows that spinel lithium manganese oxide powder formed about 973 K presents the best electrochemical performance with well separated two peaks and the highest peak current. Charge-discharge test indicates that spinel lithium manganese oxide powders calcined at higher temperatures have high discharge capacity and capacity loss, and sintered at lower temperatures has low discharge capacity and high capacity retention.

  12. Characterization of LaNiO3 prepared by sol–gel: Application to hydrogen evolution under visible light

    International Nuclear Information System (INIS)

    Khettab, M.; Omeiri, S.; Sellam, D.; Ladjouzi, M.A.; Trari, M.

    2012-01-01

    Highlights: ► Photoactive LaNiO 3 was prepared by sol–gel. ► LaNiO 3 exhibits n type conductivity it due to slight oxygen deficiency. ► LaNiO 3 was successfully for hydrogen evolution upon visible light. - Abstract: The semi conducting properties of LaNiO 3 , elaborated by sol–gel, have been investigated for the first time by the photocurrent technique and capacitance measurements. The oxide crystallizes in a distorted perovskite structure and the transport properties indicate degenerate conductivity with activation energy of 18 meV. The infrared spectrum allowed us to evaluate the band gap at 88 meV. The electrochemical behaviour has been studied in alkaline electrolyte (KOH, 0.5 M). The corrosion potential (−0.204 V SCE ) and the exchange current density (0.103 mA cm −2 ), determined from the semi logarithmic plot, indicate long lived oxide. The slope and the intercept to C −2 = 0 of the Mott Schottky plot, characteristic of n type behaviour, gave respectively an electron density (N D ) of 2.3 × 10 19 cm −3 and a flat band potential (V fb ) of −0.61 V SCE . The nature of the Nyquist plot, measured over a wide frequency range (10 −3 –10 5 Hz), shows the predominance of the bulk contribution. The arc is not centred on the real axis (−6.3°), an evidence of a constant phase element. The straight line at low frequencies is due to Warburg diffusion and the data are interpreted thanks to the Randles model. The absorption of light promotes electrons into LaNiO 3 –CB with a potential (−0.62 V SCE ) sufficient to reduce water (−0.50 V SCE ). As application, the oxide has been tested successfully for hydrogen evolution upon visible light with a rate evolution of 1.73 μmol min −1 (g catalyst) −1 and a quantum efficiency of 0.042% under full light (29 mW cm −2 ).

  13. Processing of non-oxide ceramics from sol-gel methods

    Science.gov (United States)

    Landingham, Richard; Reibold, Robert A.; Satcher, Joe

    2014-12-12

    A general procedure applied to a variety of sol-gel precursors and solvent systems for preparing and controlling homogeneous dispersions of very small particles within each other. Fine homogenous dispersions processed at elevated temperatures and controlled atmospheres make a ceramic powder to be consolidated into a component by standard commercial means: sinter, hot press, hot isostatic pressing (HIP), hot/cold extrusion, spark plasma sinter (SPS), etc.

  14. Modified lignin: Preparation and use in reversible gel via Diels-Alder reaction.

    Science.gov (United States)

    Zhou, Wanpeng; Zhang, Hui; Chen, Fangeng

    2018-02-01

    In this study, popular soda lignin was modified with either furan or maleimide ring, and the modified lignins were subjected to reversible Diels-Alder reaction. A new process was proposed to prepare the functionalized lignin. A long chain was introduced to the hydroxyl groups of lignin, and then either the furan or maleimide ring was added to the other end of the chain. The test results confirmed that either the furan ring or the maleimide ring was bound to lignin. Furan- and maleimide-functionalized lignins were also combined to generate crosslinking via Diels-Alder [4+2] cycloaddition reaction. Under appropriate conditions, the formation of a gel was identified, which reverted to liquid state after retro Diels-Alder reaction upon heating at 120°C. This study reveals the significant versatility and potential of the developed strategy for the utilization of lignin-based recyclable networks. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Judd-Ofelt Analysis of Dy3+-Activated Aluminosilicate Glasses Prepared by Sol-Gel Method

    Science.gov (United States)

    Sengthong, Buonyavong; Van Tuyen, Ho; An, Nguyen Thi Thai; Van Do, Phan; Hai, Nguyen Thi Quy; Chau, Pham Thi Minh; Quang, Vu Xuan

    2018-04-01

    Aluminosilicate (AS) glasses doped with different Dy3+ concentrations were synthesized via sol-gel method. Absorption, photoluminescence spectra and lifetime of this material have been studied. From analytical results of absorption spectra, the Judd-Ofelt (JO) parameters of prepared samples have been determined. These JO parameters combined with photoluminescence spectra have been used to evaluate transition probabilities ( A R), branching ratios ( β) and the calculated oscillator strengths of AS:Dy3+ glasses. The radiative branching ratio of 4F9/2 → 6H13/2 transition has a minimum value at 62.2% for β R which predicts that this transition in AS:Dy3+ glasses can give rise to lasing action. JO parameters show that the Ω2 increases with the increasing of Dy3+ ion concentration due to the increased polarizability of the average coordination medium and decreased average symmetry.

  16. Preparation of Rare Earth Doped Alumina-Siloxane Gel and Its ER Effect

    Institute of Scientific and Technical Information of China (English)

    李幼荣; 张明; 周兰香; 邱关明; 井上真一; 冈本宏

    2002-01-01

    Poly(methyl methacrylate) (PMMA) was used to wrap alumina-siloxane sol through emulsion polymerization. A kind of suspensions with notable ER effect was produced by fully mixing the prepared microcapsule with silicon oil. Meanwhile a series of PMMA wrapped alumina-siloxane gel doped with rare earths was obtained and its ER effect was tested, like viscosity of different rare earth ion doped samples in different powder concentrations and at different temperatures, at the same time, leak current density and dielectric constant were measured. Results show that the ER effect of this suspension is remarkable, and its stability is much better. The condition of emulsion polymerization and the mechanism of effect are discussed.

  17. Electrochemical performance of trimethylolpropane trimethylacrylate-based gel polymer electrolyte prepared by in situ thermal polymerization

    International Nuclear Information System (INIS)

    Zhou, Dong; Fan, Li-Zhen; Fan, Huanhuan; Shi, Qiao

    2013-01-01

    Cross-linked trimethylolpropane trimethylacrylate-based gel polymer electrolytes (GPE) were prepared by in situ thermal polymerization. The ionic conductivity of the GPEs are >10 −3 S cm −1 at 25 °C, and continuously increased with the increase of liquid electrolyte content. The GPEs have excellent electrochemical stability up to 5.0 V versus Li/Li + . The LiCoO 2 |TMPTMA-based GPE|graphite cells exhibit an initial discharge capacity of 129 mAh g −1 at the 0.2C, and good cycling stability with around 83% capacity retention after 100 cycles. Both the simple fabricating process of polymer cell and outstanding electrochemical performance of such new GPE make it potentially one of the most promising electrolyte materials for next generation lithium ion batteries

  18. Preparation and characterization of ultra-thin sol-gel films

    International Nuclear Information System (INIS)

    Shapiro, Leora; Marx, Sharon; Mandler, Daniel

    2007-01-01

    The formation and characterization of nanometer thick sol-gel films are reported. The films were prepared by spin-coating of a diluted solution of a silane precursor on a number of different substrates. The effect of dilution, rotation speed and nature of substrate on the thickness and homogeneity of the films was examined. Characterization of the films was carried out by profilometry, reflectance spectroscopy, atomic force microscopy, adhesion test and electrochemistry. We find that the dilution factor has a pronounced effect on the film thickness. Moreover, the time of dilution, namely, whether dilution was carried out before or after a period of hydrolysis, has a noticeable effect on the thickness as well as on the permeability of embedded species

  19. Porous MnO2 prepared by sol-gel method for electrochemical supercapacitor

    Science.gov (United States)

    Bazzi, K.; Kumar, A.; Jayakumar, O. D.; Nazri, G. A.; Naik, V. M.; Naik, R.

    2015-03-01

    MnO2 has attracted great attention as material for electrochemical pseudocapacitor due to its high theoretical specific faradic capacitance (~ 1370 F .g-1) , environmental friendliness and wide potential window in both aqueous and nonaqueous electrolytes. However, the MnO2 has a low surface area which depresses its electrochemical performance. The amorphous α-MnO2 composite was synthesized by sol gel method in the presence of the tri-block copolymer P123. Our aim is to investigate the role of P123 on the electrochemical performance of MnO2. The samples with and without P123 were prepared and characterized by x-ray diffraction (XRD), SEM, TEM and Brunauer-Emmett-Teller (BET) method. The electrochemical performances of the amorphous MnO2 composites as the electrode materials for supercapacitors were evaluated by cyclic voltammetry and AC impedance measurements in a 1M Na2SO4 solution. The results show that the sample prepared without P123 exhibited a relatively low specific capacitance of 28F .g-1, whereas the porous MnO2 prepared with P123 exhibited 117 F .g-1at 5 mV/s. The results of crystalline MnO2 composites will also be presented. The authors acknowledge the support from the Richard J. Barber Foundation for Interdisciplinary Research.

  20. Application of preparative disk gel electrophoresis for antigen purification from inclusion bodies.

    Science.gov (United States)

    Okegawa, Yuki; Koshino, Masanori; Okushima, Teruya; Motohashi, Ken

    2016-02-01

    Specific antibodies are a reliable tool to examine protein expression patterns and to determine the protein localizations within cells. Generally, recombinant proteins are used as antigens for specific antibody production. However, recombinant proteins from mammals and plants are often overexpressed as insoluble inclusion bodies in Escherichia coli. Solubilization of these inclusion bodies is desirable because soluble antigens are more suitable for injection into animals to be immunized. Furthermore, highly purified proteins are also required for specific antibody production. Plastidic acetyl-CoA carboxylase (ACCase: EC 6.4.1.2) from Arabidopsis thaliana, which catalyzes the formation of malonyl-CoA from acetyl-CoA in chloroplasts, formed inclusion bodies when the recombinant protein was overexpressed in E. coli. To obtain the purified protein to use as an antigen, we applied preparative disk gel electrophoresis for protein purification from inclusion bodies. This method is suitable for antigen preparation from inclusion bodies because the purified protein is recovered as a soluble fraction in electrode running buffer containing 0.1% sodium dodecyl sulfate that can be directly injected into immune animals, and it can be used for large-scale antigen preparation (several tens of milligrams). Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Thermal and oxidative degradation studies of formulated C-ethers by gel-permeation chromatography

    Science.gov (United States)

    Jones, W. R., Jr.; Morales, W.

    1982-01-01

    Gel-permeation chromatography was used to analyze C-ether lubricant formulations from high-temperature bearing tests and from micro-oxidation tests. Three mu-styragel columns (one 500 and two 100 A) and a tetrahydrofuran mobile phase were found to adequately separate the C-ether degradation products. The micro-oxidation tests yielded degradation results qualitatively similar to those observed from the bearing tests. Micro-oxidation tests conducted in air yielded more degradation than did tests in nitrogen. No great differences were observed between the thermal-oxidative stabilities of the two C-ether formulations or between the catalytic degradation activities of silver and M-50 steel. C-ether formulation I did yield more degradation than did formulation II in 111- and 25-hour bearing tests, respectively.

  2. Synthesis, Consolidation and Characterization of Sol-gel Derived Tantalum-Tungsten Oxide Thermite Composites

    Energy Technology Data Exchange (ETDEWEB)

    Cervantes, O [Univ. of California, Davis, CA (United States)

    2010-06-01

    Energetic composite powders consisting of sol-gel (SG) derived nanostructured tungsten oxide were produced with various amounts of micrometer-scale tantalum fuel metal. Such energetic composite powders were ignition-tested and results show that the powders are not sensitive to friction, spark and/or impact ignition. Initial consolidation experiments, using the High Pressure Spark Plasma Sintering (HPSPS) technique, on the SG derived nanostructured tungsten oxide produced samples with higher relative density than can be achieved with commercially available tungsten oxide. The SG derived nanostructured tungsten oxide with immobilized tantalum fuel metal (Ta - WO3) energetic composite was consolidated to a density of 9.17 g·cm-3 or 93% relative density. In addition, those samples were consolidated without significant pre-reaction of the constituents, thus retaining their stored chemical energy.

  3. Trimetallic oxide nanocomposites of transition metals titanium and vanadium by sol-gel technique: synthesis, characterization and electronic properties

    Science.gov (United States)

    Kumar, Amit; Mishra, Neeraj Kumar; Sachan, Komal; Ali, Md Asif; Soaham Gupta, Sachchidanand; Singh, Rajeev

    2018-04-01

    Novel titanium and vanadium based trimetallic oxide nanocomposites (TMONCs) have been synthesized using metal salts of titanium-vanadium along with three others metals viz. tin, aluminium and zinc as precursors by the sol-gel method. Aqueous ammonia and hydrazine hydrate were used as the reducing agents. The preparations of nanocomposites were monitored by observing the visual changes during each step of synthesis. The synthesized TMONCs were characterized using UV–vis, SEM, EDX, TEM and DLS. Band gap of the synthesized TMONCs ranges from 3–4.5 eV determined using tauc plot. FTIR study revealed the molecular stretching and bending peaks of corresponding M–O/M–O–M bonds thus confirming their formation. Molecular composition and particle size were determined using EDX and DLS respectively. Molecular shape, size and surface morphology have been examined by SEM and TEM.

  4. Studies on Y{sub 2}SiO{sub 5}:Ce phosphors prepared by gel combustion using new fuels

    Energy Technology Data Exchange (ETDEWEB)

    Muresan, L.E., E-mail: laura_muresan2003@yahoo.com [“Raluca Ripan” Institute for Research in Chemistry, Babeş Bolyai University, Fântânele 30, 400294 Cluj-Napoca (Romania); Oprea, B.F.; Cadis, A.I.; Perhaita, I. [“Raluca Ripan” Institute for Research in Chemistry, Babeş Bolyai University, Fântânele 30, 400294 Cluj-Napoca (Romania); Ponta, O. [Faculty of Physics, Babeş Bolyai University, 400084 Cluj-Napoca (Romania)

    2014-12-05

    Highlights: • Y{sub 2}SiO{sub 5}:Ce was prepared by combustion using aspartic or glutamic acid as fuels. • Combustion process occurs differently depending on the fuels amount. • Single phase X2-Y{sub 2}SiO{sub 5} phosphors were obtained in fuel rich conditions. • PL measurements indicate that aspartic acid is a better fuel than glutamic. • Optimal preparative conditions were established for synthesis of Y{sub 2}SiO{sub 5}:Ce. - Abstract: Cerium activated yttrium silicate (Y{sub 2}SiO{sub 5}:Ce) phosphors were prepared by combustion, using yttrium–cerium nitrate as oxidizer, aspartic or glutamic acid as fuel and TEOS as source of silicon. In this study, aspartic and glutamic acid are used for the first time for the synthesis of Y{sub 2}SiO{sub 5}:Ce phosphors. The fuels molar amount was varied from 0.5 mol to 1.5 mol in order to reveal the thermal behavior of intermediary products (gels and ashes) same as the structural and luminescent characteristics of final products (phosphors). According to thermal analysis correlated with FTIR and XPS investigations, the combustion process occurs differently depending on the fuel amount; unreacted nitrate compounds have been identified in fuel lean conditions and carbonate based compounds along with organic residue in rich fuel conditions. The conversion to well crystallized silicates was revealed by changes of FTIR vibration bands and confirmed by XRD measurements. Based on luminescent spectra, aspartic acid is a better fuel than glutamic acid. A positive effect on the luminescence have been observed for samples fired in air due to complete remove of organic residue. The best luminescence was obtained for combustions with 0.75 mol aspartic acid and 1.25 mol glutamic respectively, fired at 1400 °C for 4 h in air atmosphere.

  5. Comparison of Preparation Methods of Copper Based PGMFree Diesel-Soot Oxidation Catalysts

    Directory of Open Access Journals (Sweden)

    R. Prasad

    2011-05-01

    Full Text Available CuO-CeO2 systems have been proposed as a promising catalyst for low temperature diesel-soot oxidation. CuO-CeO2 catalysts prepared by various methods were examined for air oxidation of the soot in a semi batch tubular flow reactor. The air oxidation of soot was carried out under tight contact with soot/catalyst ratio of 1/10. Air flow rate was 150 ml/min, soot-catalyst mixture was 110 mg, heating rate was 5 0C/min. Prepared catalysts were calcined at 500 0C and their stability was examined by further heating to 800 0C for 4 hours. It was found that the selectivity of all the catalysts was nearly 100% to CO2 production. It was observed that the activity and stability of the catalysts greatly influenced by the preparation methods. The strong interaction between CuO and CeO2 is closely related to the preparation route that plays a crucial role in the soot oxidation over the CuO-CeO2 catalysts. The ranking order of the preparation methods of the catalysts in the soot oxidation performance is as follows: sol-gel > urea nitrate combustion > Urea gelation method > thermal decomposition > co-precipitation. Copyright © 2011 BCREC UNDIP. All rights reserved.(Received: 27th June 2010, Revised: 7th August 2010; Accepted: 13rd October 2010[How to Cite: R. Prasad, V.R. Bella. (2011. Comparison of Preparation Methods of Copper Based PGMFree Diesel-Soot Oxidation Catalysts. Bulletin of Chemical Reaction Engineering and Catalysis, 6(1: 15-21. doi:10.9767/bcrec.6.1.822.15-21][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.6.1.822.15-21 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/822 | View in 

  6. Electrochemical preparation of new uranium oxide phases

    International Nuclear Information System (INIS)

    Smolenskij, V.V.; Lyalyushkin, N.V.; Bove, A.L.; Komarov, V.K.; Kapshukov, I.I.

    1992-01-01

    Behaviour of uranium ions in oxidation states 3+ and 4+ in molten chlorides of alkali metals in the temperature range of 700-900 degC in the atmosphere of an inert gas was studied by the method of cyclic voltametry. It is shown that as a result of introduction of crystal uranium dioxide into the salt melt formation of uranium oxide ions of the composition UO + and UO 2+ occurs, the ions participating in electrode reactions and bringing about formation of the following uranium oxides on the cathode: UO and, presumably, U 3 O 4 . Oxides UO and U 3 O 4 are thermodynamically unstable at low temperatures and decompose into uranium oxide of the composition UO 2-x , where x varies from 0 to 0.05, and metal uranium

  7. A novel gel combustion procedure for the preparation of foam and porous pellets of UO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Sanjay Kumar, D. [Fuel Chemistry Division, Materials Chemistry and Metal Fuel Cycle Group, Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam, 603102, Tamil Nadu (India); Ananthasivan, K., E-mail: asivan@igcar.gov.in [Fuel Chemistry Division, Materials Chemistry and Metal Fuel Cycle Group, Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam, 603102, Tamil Nadu (India); Venkata Krishnan, R.; Maji, Dasarath [Fuel Chemistry Division, Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, 603102, Tamil Nadu (India); Dasgupta, Arup [Microscopy and Thermo-Physical Property Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Homi Bhabha National Institute, Kalpakkam, 603102, Tamil Nadu (India)

    2017-01-15

    In this study, it has been demonstrated for the first time how sucrose gel-combustion could be used for the preparation of UO{sub 2} foam. Further the citrate gel-combustion was gainfully used for preparing porous pellets of UO{sub 2}. The utility of two-step sintering (1073 K for 30 min and 1473 K for 4 h) for obtaining these porous bodies was demonstrated for the first time. The foams and pellets possessed meso and macro pores. A starting mixture with sucrose to nitrate ratio of 2.4 was found to yield urania foam with adequate crush strength. The porous pellets were found to possess better handling strength, lesser carbon residue and higher overall density than the foam. A citric acid to nitrate ratio 0.25 in the starting mixture, 180 MPa compaction pressure were optimal for obtaining a pellet with 40% porosity. - Highlights: • Urania foam was successfully prepared for the first time by using sucrose-gel precursor method. • Porous urania pellets were successfully prepared for the first time by using citrate gel-combustion method. • The foam comprised both meso and macro pores, possessed good crush strength and porosity. • Citric acid to nitrate ratio of 0.25 and a compaction pressure of 180 MPa were best suited for the preparation of porous pellets.

  8. Novel synthesis strategy for the preparation of individual phytosterol oxides.

    Science.gov (United States)

    Gao, Junlan; Yue, Qiulin; Ji, Yishun; Cheng, Beijiu; Zhang, Xin

    2013-01-30

    Sterols (cholesterol and phytosterols) are important structural components of cell membranes and major constituents of lipid metabolism. Research on their oxides, such as the factors affecting oxidation, oxides' structures, and qualitative and quantitative analysis, aroused more attention in this decade. However, the biological roles of individual phytosterol oxides are still unclear because no commercial individual phytosterol oxide standards are available. Different from the traditional chemical synthesis, in the present study, chemical synthesis from a starting phytosterol mixture followed with a semipreparative HPLC separation produced individual oxides. TLC and analytical HPLC were used here to not only monitor the reaction process but also specifically analyze the synthetic intermediates and oxides. The chromatographic results exhibited strict rules and similar characteristics. Finally, for the first time, four individual phytosterol oxides were successfully separated and collected by a semipreparative HPLC system, thus providing a novel strategy for the preparation of individual phytosterol oxides.

  9. Optical Constants of Crystallized TiO2 Coatings Prepared by Sol-Gel Process

    Directory of Open Access Journals (Sweden)

    Jun Shen

    2013-07-01

    Full Text Available Titanium oxide coatings have been deposited by the sol-gel dip-coating method. Crystallization of titanium oxide coatings was then achieved through thermal annealing at temperatures above 400 °C. The structural properties and surface morphology of the crystallized coatings were studied by micro-Raman spectroscopy and atomic force microscopy, respectively. Characterization technique, based on least-square fitting to the measured reflectance and transmittance spectra, is used to determine the refractive indices of the crystallized TiO2 coatings. The stability of the synthesized sol was also investigated by dynamic light scattering particle size analyzer. The influence of the thermal annealing on the optical properties was then discussed. The increase in refractive index with high temperature thermal annealing process was observed, obtaining refractive index values from 1.98 to 2.57 at He-Ne laser wavelength of 633 nm. The Raman spectroscopy and atomic force microscopy studies indicate that the index variation is due to the changes in crystalline phase, density, and morphology during thermal annealing.

  10. Sol-gel process for preparation of YBa2Cu4O8 from acidic acetates/ammonia/ascorbic acid systems

    International Nuclear Information System (INIS)

    Deptula, A.; Lada, W.; Olczak, T.; Goretta, K.C.

    1997-01-01

    YBa 2 Cu 4 O x sols were prepared by addition of ammonia to acidic acetate solutions of Y 3+ , Ba 2+ , and Cu 2+ . Ascorbic acid was added to part of the sol. The resultant sols were gelled to a shard or a coating by evaporation at 60 C. Addition of ethanol to the sols facilitated formation of gel coatings, fabricated by a dipping technique, on Ag or glass or substrates. At 100 C, gels formed in the presence of ascorbic acid were perfectly amorphous, in contrast to crystalline acetate gels. The quality of coatings prepared from ascorbate gels was superior to that of acetate gel coatings

  11. Zirconium titanate thin film prepared by surface sol-gel process and effects of thickness on dielectric property

    CERN Document Server

    Kim, C H

    2002-01-01

    Single phase of multicomponent oxide ZrTiO sub 4 film could be prepared through surface sol-gel route simply by coating the mixture of 100mM zirconium butoxide and titanium butoxide on Pt/Ti/SiO sub 2 /Si(100) substrate, following pyrolysis at 450 .deg. C, and annealing it at 770 .deg. C. The dielectric constant of the film was reduced as the film thickness decreased due to of the interfacial effects caused by layer/electrode and a few voids inside the multilayer. However, the dielectric property was independent of applied dc bias sweeps voltage (-2 to +2 V). The dielectric constant of bulk film, 31.9, estimated using series-connected capacitor model was independent of film thickness and frequency in the measurement range, but theoretical interfacial thickness, t sub i , was dependent on the frequency. It reached a saturated t sub i value, 6.9 A, at high frequency by extraction of some capacitance component formed at low frequency range. The dielectric constant of bulk ZrTiO sub 4 pellet-shaped material was 3...

  12. New synthesis parameters of GGG:Nd nanocrystalline powder prepared by sol–gel method: Structural and spectroscopic investigation

    Energy Technology Data Exchange (ETDEWEB)

    Alshikh Mohamad, Yassin, E-mail: yassinm@mail.ru; Atassi, Yomen; Moussa, Zafer

    2015-09-15

    GGG:Nd nanopowder is synthesized by the sol–gel method using formic acid and acetic acid as chelating agents and ethylene glycol as a cross linking agent. TGA–DSC, XRD, photoluminescence spectroscopy and fluorescence life time analysis (τ) are used to characterize the powder. XRD is used to optimize the synthesis parameters. According to XRD, complete phase of GGG nanopowder is formed at 800 °C for 1 min. Fluorescence life time analyses reveal that the optimum crystallization temperature is 1000 °C. - Highlights: • GGG:Nd nanopowder was prepared using formic acid by the sol gel method. • Optimization of sol gel parameters was done. • GGG phase formation was complete at 800 °C for 1 min • According to τ measurements, optimal temperature treatment is at 1000 °C. • Nanopowder prepared with formic acid was better than that formed with acetic acid.

  13. Synthesis and characterization of mixtures of cobalt and titanium oxides by mechanical alloyed and Sol-Gel;Sintesis y caracterizacion de mezclas de oxidos de cobalto y titanio por aleado mecanico y Sol-Gel

    Energy Technology Data Exchange (ETDEWEB)

    Basurto S, R.; Bonifacio M, J.; Fernandez V, S. M., E-mail: rafael.basurto@inin.gob.m [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico)

    2009-07-01

    The mechanical alloyed techniques continued by combustion and Sol-Gel method, were used for the synthesis of CoTiO{sub 3}. With the first technique was used Co{sub 3}O{sub 4} obtained in a balls mill SPEX in argon atmosphere, using cobalt nitrate and urea, the combustion is realized at 400 and 500 C, the characterization by X-ray diffraction showed the obtaining of the valence oxide mixed of cobalt with crystallite size from 10 to 12.5 nm and the particle size of 60 to 75 nm was obtained by scanning electron microscopy. To prepare the CoTiO{sub 3}, the obtained Co{sub 3}O{sub 4} was mixed with TiO{sub 2} on a relationship in weight (1:1) and with a milling time of 2.5 h and the combustion at 800 C. the mixed oxide of titanium cobalt was also obtained by the Sol-Gel technique starting from cobalt chloride and titanium propoxide in acetic-water acid, the gel is burned to temperature of 300, 500, 700 and 900 C, finding that this last temperature it is that provides the compound with crystalline size from 50 to 75 nm. (Author)

  14. Hydrogen permeation through steel coated with erbium oxide by sol-gel method

    International Nuclear Information System (INIS)

    Yao Zhenyu; Suzuki, Akihiro; Levchuk, Denis; Chikada, Takumi; Tanaka, Teruya; Muroga, Takeo; Terai, Takayuki

    2009-01-01

    Er 2 O 3 coating is formed on austenitic stainless steel 316ss by sol-gel method. The results showed good crystallization of coating by baking in high purity flowing-argon at 973 K, and indicated that a little oxygen in baking atmosphere is necessary to crystallization of coating. The best baking temperature could be thought as 973 K, to get good crystallization of coating and avoid strong oxidation of steel substrate. The deuterium permeation test was performed for coated and bare 316ss, to evaluate the property of Er 2 O 3 sol-gel coating as a potential tritium permeation barrier. In this study, the deuterium permeability of coated 316ss is about 1-2 orders of magnitude lower than that of bare 316ss, and is about 2-3 orders of magnitude than the referred data of bare Eurofer97 and F82H martensitic steel.

  15. Progress of studies on preparation of TiO2 photocatalysts with sol-gel auto igniting synthesis

    Science.gov (United States)

    Wu, Di; Shi, Zaifeng; Zhang, Xiaopeng; Xinghui, Wu

    2017-11-01

    In this article, influencing factors on the kinetics of the process of Sol-gel Auto igniting Synthesis (SAS) which is an advanced technology for preparing nanometer particles of inorganic materials were reviewed. The studies on preparing of nanometer TiO2 photocatalysts with SAS were focused. It was concluded that SAS will play an important role in practical preparing of high-pure nanometer TiO2 powder, and as a technical support, preparation of titania TiO2 from titanic iron ore with SAS is feasible and practicable.

  16. A sol-gel method for preparing ZnO quantum dots with strong blue emission

    International Nuclear Information System (INIS)

    Chen Zhong; Li Xiaoxia; Du Guoping; Chen Nan; Suen, Andy Y.M.

    2011-01-01

    ZnO quantum dots (QDs) with strong blue emission have been successfully synthesized by sol-gel method, and their crystal structures, sizes, and photoluminescence properties were characterized by X-ray diffractometer, scanning electron microscope, and ultraviolet-visible spectroscopy. It has been found that ZnO QDs had a hexagonal wurtzite crystal structure, and their average diameter was about 16.0-32.2 nm. Both the reaction time and temperature were found to have a strong influence on the average size and photoluminescence properties of ZnO QDs. Longer reaction time and higher reaction temperature resulted in larger average size for ZnO QDs. It has been shown that at reaction temperature 60 deg. C the emission intensity for ZnO QDs increased first with reaction time before 7 h and then decreased after 7 h. For the same reaction time 7 h, ZnO QDs synthesized at 60 deg. C showed the strongest emission intensity. It was found that annealing in nitrogen, vacuum, and air all resulted in an increase of the size of ZnO QDs and a reduction in their photoluminescence. The dependence of the size and properties of ZnO QDs on the reaction parameters as well as the annealing conditions has been discussed. - Highlights: → ZnO quantum dots (QDs) with strong blue emission were prepared by sol-gel method. → ZnO QDs had a pure spectral blue with the chromaticity coordinates (0.166, 0.215). → Optimal reaction time and temperature were 7 h and 60 deg. C, respectively.

  17. A strategic approach for preparation of oxide nanomaterials

    Indian Academy of Sciences (India)

    A microwave assisted solvothermal method is described for rapid preparation of nano-oxides. This method is based on exploiting differential dielectric constants to induce preferred heating and decomposition of the oxide precursors in the presence of suitable capping agents. This strategic approach has been used to ...

  18. Synthesis and characterization of zinc oxide thin films prepared by ...

    African Journals Online (AJOL)

    Zinc oxide thin films were prepared with ammonia/ammonium chloride buffer as the reaction moderating agent in the chemical bath deposition technique. An observable color change during the reaction due to variations in the reactants concentration indicated the existence of the cupric (CuO) and cuprous (Cu2O) oxides ...

  19. Effect of pyrolysis temperature on the properties of carbon/nickel nanocomposites prepared by sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Mansour, N. Ben, E-mail: Nabil.Benmansour@fsg.rnu.tn [Laboratory of Physics of Materials and Nanomaterials Applied at Environment (LaPhyMNE), Gabès University, Faculty of Sciences in Gabès, Gabès (Tunisia); Najeh, I.; Mansouri, S. [Laboratory of Physics of Materials and Nanomaterials Applied at Environment (LaPhyMNE), Gabès University, Faculty of Sciences in Gabès, Gabès (Tunisia); El Mir, L. [Laboratory of Physics of Materials and Nanomaterials Applied at Environment (LaPhyMNE), Gabès University, Faculty of Sciences in Gabès, Gabès (Tunisia); Al Imam Mohammad Ibn Saud Islamic University (IMSIU), College of Sciences, Department of Physics, Riyadh 11623 (Saudi Arabia)

    2015-05-15

    Highlights: • Synthesis of nickel oxide nanoparticles in carbon structures. • Presence of multiwall carbon nanotubes (MWNT) around Ni nanoparticles for the sample treated at high pyrolysis temperature. • DC conductivity exhibited the presence of conduction percolation phenomenon and the dominance of conduction model 3D-GVRH in the studied materials. • From AC conductance PF/Ni nanocomposites have two behaviors: semiconductor and metal, depending on the pyrolysis temperature. • Appearance of a negative differential resistance (NDR) at room temperature in the sample treated at 600 °C. - Abstract: Carbon–nickel nanocomposites (C/Ni) were prepared by sol–gel method after the incorporation of nickel oxide (NiO) nanoparticles in organic matrix based on pyrogallol-formaldehyde (PF). The nanocomposites heated under inert atmosphere have been characterized by various techniques such as X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), and electrical analysis. The XRD spectra exhibited the presence of NiO or metallic Ni phase in amorphous carbon matrix at low pyrolysis temperature, while at 1000 °C the graphite structure line was observed. The TEM images indicate the presence of multiwall carbon nanotubes (MWNT) around Ni nanoparticles for the sample treated at high pyrolysis temperature. The AC conductance shows that our nanocomposites have two behaviors: semiconductor and metal, depending on the pyrolysis temperature. The voltage–current V(I) characteristics of the compound show two different regions: an Ohmic region at low current and a negative differential resistance (NDR) region at higher current. This switching phenomenal behavior has been explained by an electrothermal model.

  20. Effect of pyrolysis temperature on the properties of carbon/nickel nanocomposites prepared by sol–gel method

    International Nuclear Information System (INIS)

    Mansour, N. Ben; Najeh, I.; Mansouri, S.; El Mir, L.

    2015-01-01

    Highlights: • Synthesis of nickel oxide nanoparticles in carbon structures. • Presence of multiwall carbon nanotubes (MWNT) around Ni nanoparticles for the sample treated at high pyrolysis temperature. • DC conductivity exhibited the presence of conduction percolation phenomenon and the dominance of conduction model 3D-GVRH in the studied materials. • From AC conductance PF/Ni nanocomposites have two behaviors: semiconductor and metal, depending on the pyrolysis temperature. • Appearance of a negative differential resistance (NDR) at room temperature in the sample treated at 600 °C. - Abstract: Carbon–nickel nanocomposites (C/Ni) were prepared by sol–gel method after the incorporation of nickel oxide (NiO) nanoparticles in organic matrix based on pyrogallol-formaldehyde (PF). The nanocomposites heated under inert atmosphere have been characterized by various techniques such as X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), and electrical analysis. The XRD spectra exhibited the presence of NiO or metallic Ni phase in amorphous carbon matrix at low pyrolysis temperature, while at 1000 °C the graphite structure line was observed. The TEM images indicate the presence of multiwall carbon nanotubes (MWNT) around Ni nanoparticles for the sample treated at high pyrolysis temperature. The AC conductance shows that our nanocomposites have two behaviors: semiconductor and metal, depending on the pyrolysis temperature. The voltage–current V(I) characteristics of the compound show two different regions: an Ohmic region at low current and a negative differential resistance (NDR) region at higher current. This switching phenomenal behavior has been explained by an electrothermal model

  1. The effect of reaction temperature on the room temperature ferromagnetic property of sol-gel derived tin oxide nanocrystal

    Science.gov (United States)

    Sakthiraj, K.; Hema, M.; Balachandra Kumar, K.

    2018-06-01

    In the present study, nanocrystalline tin oxide materials were prepared using sol-gel method with different reaction temperatures (25 °C, 50 °C, 75 °C & 90 °C) and the relation between the room temperature ferromagnetic property of the sample with processing temperature has been analysed. The X-ray diffraction pattern and infrared absorption spectra of the as-prepared samples confirm the purity of the samples. Transmission electron microscopy images visualize the particle size variation with respect to reaction temperature. The photoluminescence spectra of the samples demonstrate that luminescence process in materials is originated due to the electron transition mediated by defect centres. The room temperature ferromagnetic property is observed in all the samples with different amount, which was confirmed using vibrating sample magnetometer measurements. The saturation magnetization value of the as-prepared samples is increased with increasing the reaction temperature. From the photoluminescence & magnetic measurements we accomplished that, more amount of surface defects like oxygen vacancy and tin interstitial are created due to the increase in reaction temperature and it controls the ferromagnetic property of the samples.

  2. Simple Preparation of ZnO Nano-layer by Sol-Gel Method as Active Electrode in P3HT/ZnO Heterojunction Solar Cell

    Science.gov (United States)

    Aprilia, Annisa; Herman, Hidayat, Rahmat

    2010-10-01

    Highly transparent undoped ZnO thin films have been prepared on glass and indium tin oxide substrates with simple process by sol-gel route and dip-coating deposition. Gel precursor of ZnO was prepared from zinc acetat dehydrate solution in methanol with the addition of trietylamine as stabilizing agent. Thin layer of gel precursor was prepared by dip coating and then followed by calcination at 400° C for 5 minute in air atmosphere. The thickness of the resulted ZnO thin film produced by ten times coating is about 150 nm. The films shows high transmittance larger than 98% in the visible region (400-800 nm). Absorption is observed in the UV region with absorption onset at about 390 nm indicating varying band gap between 3.18 eV until 3.23 eV depending on the number of coating layer. The AFM image shows that the films seems to be constructed from random stacking of nano-sized ZnO particle in the order of 50 nm. Among the prepared samples, the lowest resistivity is about 1.8×107 Ωm observed in the five-layer coating film. In order to fabricate solar cell structure, P3HT was deposited onto the ZnO thin film layer by spin casting technique and then followed by metal (Au) layer deposition by thermal evaporation. The formed solar cell has the inverted type solar cell with ITO/ZnO/P3HT/Au configuration. By the insertion ZnO layer, the photocurrent was improved by more than ten orders of magnitude in comparison to that of without ZnO layer. The measured photocurrent decreases at large number of coating layer which is supposed to be related with the current limitation by the effective carrier path length in ZnO layer.

  3. Prontonic ceramic membrane fuel cells with layered GdBaCo{sub 2}O{sub 5+x} cathode prepared by gel-casting and suspension spray

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Bin; Zhang, Shangquan; Zhang, Linchao; Bi, Lei; Ding, Hanping; Liu, Xingqin; Gao, Jianfeng; Meng, Guangyao [Department of Materials Science and Engineering, University of Science and Technology of China (USTC), Hefei 230026 (China)

    2008-03-01

    In order to develop a simple and cost-effective route to fabricate protonic ceramic membrane fuel cells (PCMFCs) with layered GdBaCo{sub 2}O{sub 5+x} (GBCO) cathode, a dense BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.2}O{sub 3-{delta}} (BZCY7) electrolyte was fabricated on a porous anode by gel-casting and suspension spray. The porous NiO-BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.2}O{sub 3-{delta}} (NiO-BZCY7) anode was directly prepared from metal oxide (NiO, BaCO{sub 3}, ZrO{sub 2}, CeO{sub 2} and Y{sub 2}O{sub 3}) by a simple gel-casting process. A suspension of BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.2}O{sub 3-{delta}} powders synthesized by gel-casting was then employed to deposit BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.2}O{sub 3-{delta}} (BZCY7) thin layer by pressurized spray process on NiO-BZCY7 anode. The bi-layer with 10 {mu}m dense BZCY7 electrolyte was obtained by co-sintering at 1400 C for 5 h. With layered GBCO cathode synthesized by gel-casting on the bi-layer, single cells were assembled and tested with H{sub 2} as fuel and the static air as oxidant. An open-circuit potential of 0.98 V, a maximum power density of 266 mW cm{sup -2}, and a low polarization resistance of the electrodes of 0.16 {omega} cm{sup 2} was achieved at 700 C. (author)

  4. Self-healing guar gum and guar gum-multiwalled carbon nanotubes nanocomposite gels prepared in an ionic liquid.

    Science.gov (United States)

    Sharma, Mukesh; Mondal, Dibyendu; Mukesh, Chandrakant; Prasad, Kamalesh

    2013-10-15

    Guar gum is a galactomannan extracted from the seed of the leguminous shrub Cyamopsis tetragonoloba. It was found to form a soft viscoelastic gel in 1-butyl-3-methylimidazolium chloride, an ionic liquid at an optimized concentration of 10%w/v. A nanocomposite gel of the gum with enhanced strength could be prepared with 0.2%w/v of multiwalled carbon nanotubes (MWCNTs) in the ionic liquid. When the gels thus prepared were subjected to surface fractures or bisected completely, they found to self-heal at room temperature without any external interventions. The self-healing process could be repeated several times. These viscoelastic gel systems showed thixotropic nature and recovery of the storage modulus with time for several cycles was observed upon rheological investigations. The interaction took place between ionic liquid, guar gum and MWCNT was studied by SEM, TEM, FT-IR, powder XRD and rheometry. The results suggested that, upon standing at room temperature development of electrostatic interactions and the van der Waals interactions among the ionic liquid molecules facilitated the formation of reversible noncovalent bonds and eventually activated the self-healing in the gel systems through appropriate chain entanglements. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Preparation of Photocrosslinked Fish Elastin Polypeptide/Microfibrillated Cellulose Composite Gels with Elastic Properties for Biomaterial Applications

    Directory of Open Access Journals (Sweden)

    Shinya Yano

    2015-01-01

    Full Text Available Photocrosslinked hydrogels reinforced by microfibrillated cellulose (MFC were prepared from a methacrylate-functionalized fish elastin polypeptide and MFC dispersed in dimethylsulfoxide (DMSO. First, a water-soluble elastin peptide with a molecular weight of ca. 500 g/mol from the fish bulbus arteriosus was polymerized by N,N′-dicyclohexylcarbodiimide (DCC, a condensation reagent, and then modified with 2-isocyanatoethyl methacrylate (MOI to yield a photocrosslinkable fish elastin polypeptide. The product was dissolved in DMSO and irradiated with UV light in the presence of a radical photoinitiator. We obtained hydrogels successfully by substitution of DMSO with water. The composite gel with MFC was prepared by UV irradiation of the photocrosslinkable elastin polypeptide mixed with dispersed MFC in DMSO, followed by substitution of DMSO with water. The tensile test of the composite gels revealed that the addition of MFC improved the tensile properties, and the shape of the stress–strain curve of the composite gel became more similar to the typical shape of an elastic material with an increase of MFC content. The rheology measurement showed that the elastic modulus of the composite gel increased with an increase of MFC content. The cell proliferation test on the composite gel showed no toxicity.

  6. Properties of form-stable paraffin/silicon dioxide/expanded graphite phase change composites prepared by sol–gel method

    International Nuclear Information System (INIS)

    Li, Min; Wu, Zhishen; Tan, Jinmiao

    2012-01-01

    Highlights: ► Paraffin/SiO 2 /EG composite PCM was prepared with sol–gel method. ► The thermal conductivity of SiO 2 /paraffin/EG is 94.7% higher than paraffin. ► The latent heat of paraffin/SiO 2 /EG composite is 104.4 J/g. -- Abstract: A form-stable paraffin/silicon dioxide (SiO 2 )/expanded graphite (EG) composite phase change material (PCM) was prepared by sol–gel method. Silica gel acts as the supporting material and EG is used to increase the thermal conductivity. The mass fractions of silicon oxide and graphite are 20.8% and 7.2%, respectively. The composite PCM was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transformation infrared spectroscopy (FTIR) method. Thermal properties and thermal stability of the composite PCM were studied using differential scanning calorimetry (DSC). The result shows that paraffin was well dispersed in the network of silica gel and there is no chemical reaction between them. The phase change temperature of the paraffin/SiO 2 composite and the paraffin/SiO 2 /EG composite are 27.53 °C and 27.72 °C, respectively. The latent heat of the paraffin/SiO 2 composite and the paraffin/SiO 2 /EG composite are 112.8 J/g and 104.4 J/g, respectively. The thermal conductivity of the SiO 2 /paraffin composite and the SiO 2 /paraffin/EG composite are 28.2% and 94.7% higher than that of paraffin.

  7. Electrochemical corrosion behavior of composite MAO/sol-gel coatings on magnesium alloy AZ91D using combined micro-arc oxidation and sol-gel technique

    International Nuclear Information System (INIS)

    Shang Wei; Chen Baizhen; Shi Xichang; Chen Ya; Xiao Xiang

    2009-01-01

    Protective composite coatings were obtained on a magnesium alloy by micro-arc oxidation (MAO) and sol-gel technique. The coatings consisted of a MAO layer and a sol-gel layer. The microstructure and composition of the MAO coating and the composite coatings were analyzed by scanning electron microscopy (SEM) and energy dispersive X-rays (EDX). Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and total immersion tests were used to evaluate the corrosion behavior of these coatings in a 3.5 wt.% NaCl solution. The results show that the sol-gel layer provides corrosion protection by physically sealing the pores in the MAO coating and acting as a barrier. The composite coatings can suppress the corrosion process by preventing the corrosive ions from transferring or diffusing to the magnesium alloy substrate. This enhances the corrosion resistance of the magnesium alloy AZ91D significantly

  8. Synthesis of Copper-Based Transparent Conductive Oxides with Delafossite Structure via Sol-Gel Processing

    OpenAIRE

    Götzendörfer, Stefan

    2011-01-01

    Starting off with solubility experiments of possible precursors, the present study reveals the whole development of a sol gel processing route for transparent p type semiconductive thin films with delafossite structure right to the fabrication of functional p-n junctions. The versatile sol formulation could successfully be modified for several oxide compositions, enabling the synthesis of CuAlO2, CuCrO2, CuMnO2, CuFeO2 and more. Although several differences in the sintering behaviour of powde...

  9. Preparation and characterization of dialdehyde starch by one-step acid hydrolysis and oxidation.

    Science.gov (United States)

    Zuo, Yingfeng; Liu, Wenjie; Xiao, Junhua; Zhao, Xing; Zhu, Ying; Wu, Yiqiang

    2017-10-01

    Dialdehyde starch was prepared by one-step synthesis of acid hydrolysis and oxidation, using corn starch as the raw material, sodium periodate (NaIO 4 ) as the oxidant, and hydrochloric acid (HCl) as the acid solution. The prepared dialdehyde starch was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and gel permeation chromatography (GPC). The results confirmed that oxidation occurred between the starch and NaIO 4 . The acid hydrolysis reaction reduced the molecular weight of starch and effectively improved the aldehyde group contents (92.7%). Scanning electron microscope (SEM) analysis indicated that the average particle size decreased after acid hydrolysis and oxidation reaction. X-ray diffraction (XRD) and thermal gravimetric analyzer (TGA) analysis demonstrated that the crystallinity of the obtained dialdehyde starch showed a downward trend and a decelerated thermal decomposition rate. The starch after acid hydrolysis and oxidation exhibited lower hot paste viscosity and higher reactivity. Copyright © 2017. Published by Elsevier B.V.

  10. Optical ph sensing material prepared from doped sol-gel film for use in acid-base titration

    Directory of Open Access Journals (Sweden)

    Musa Ahmad

    2017-11-01

    Full Text Available An optical pH sensing material has been prepared in this study by using sol-gel technique. Bromothymol blue, bromophenol blue and thymol blue were chosen in this study as acidbase indicators for strong acid-strong base, strong acid-weak base and weak acid-strong base titration, respectively. The results show that these indicators could be successfully entrapped inside the sol-gel film and still maintain its chemical behaviour as in solution. The entrapped acid-base indicators respond well to any pH changes and could be used to determine the end-point of the acid-base titration.

  11. Optical ph sensing material prepared from doped sol-gel film for use in acid-base titration

    OpenAIRE

    Musa Ahmad; T.W. Tan

    2017-01-01

    An optical pH sensing material has been prepared in this study by using sol-gel technique. Bromothymol blue, bromophenol blue and thymol blue were chosen in this study as acidbase indicators for strong acid-strong base, strong acid-weak base and weak acid-strong base titration, respectively. The results show that these indicators could be successfully entrapped inside the sol-gel film and still maintain its chemical behaviour as in solution. The entrapped acid-base indicators respond well to ...

  12. Sol-gel process for preparing YBa2Cu4O8 precursors from Y, Ba, and Cu acidic acetates/ammonia/ascorbic acid systems

    International Nuclear Information System (INIS)

    Deptula, A.; Lada, W.; Olczak, T.; Goretta, K.C.

    1995-08-01

    Sols were prepared by addition of ammonia to acidic acetate solutions of Y 3+ , Ba 2+ , and Cu 2+ . Ascorbic acid was added to a part of the sol. The resultant sols were gelled to a shard, a film, or microspheres by evaporation at 60 C or by extraction of water from drops of emulsion suspended in 2-ethylhexanol-1. Addition of ethanol to the sols facilitated the formation of gel films, fabricated by a dipping technique, on glass or silver substrates. At 100 C, gels that were formed in the presence of ascorbic acid were perfectly amorphous, in contrast to the crystalline acetate gels. Conversion of the amorphous ascorbate gels to final products was easier than for the acetate gels. The quality of coatings prepared from ascorbate gels was superior to that of acetate gel coatings

  13. Development of bufferless gel electrophoresis chip for easy preparation and rapid DNA separation.

    Science.gov (United States)

    Oleksandrov, Sergiy; Aman, Abdurazak; Lim, Wanyoung; Kim, Younghee; Bae, Nam Ho; Lee, Kyoung G; Lee, Seok Jae; Park, Sungsu

    2018-02-01

    This work presents a handy, fast, and compact bufferless gel electrophoresis chip (BGEC), which consists of precast agarose gel confined in a disposable plastic body with electrodes. It does not require large volumes of buffer to fill reservoirs, or the process of immersing the gel in the buffer. It withstands voltages up to 28.4 V/cm, thereby allowing DNA separation within 10 min with a similar separation capability to the standard gel electrophoresis. The results suggest that our BGEC is highly suitable for in situ gel electrophoresis in forensic, epidemiological settings and crime scenes where standard gel electrophoresis equipment cannot be brought in while quick results are needed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Híbridos de poli(oxido de etileno-b-amida-6 e ZrO2 sol-gel: preparação, caracterização e aplicação em processos de separação por membranas Hybrids of poly(ethylene oxide-b-amide-6 and ZrO2 sol-gel: preparation, characterization and application in membrane separation processes

    Directory of Open Access Journals (Sweden)

    Rita A. Zoppi

    2000-06-01

    Full Text Available Híbridos constituídos de poli(óxido de etileno-b-amida-6, PEBAX, e óxido de zircônio foram preparados a partir da hidrólise e condensação do tetraisopropóxido de zircônio em solução contendo o polímero orgânico dissolvido. Estes foram caracterizados por termogravimetria, calorimetria diferencial de varredura, espectroscopia na região do infravermelho e microscopia eletrônica. Os resultados obtidos mostraram que a incorporação da fase inorgânica parece promover a degradação do polímero orgânico. Membranas compostas constituídas de um suporte poroso de poli(fluoreto de vinilideno, PVDF, e uma camada filtrante de PEBAX/ZrO2 foram preparadas e caracterizadas por microscopia eletrônica. Foram realizados ensaios de permeação de água e de soluções aquosas contendo poli(etileno glicol de diferentes massas molares. Para determinar a rejeição de fosfato, foram realizados ensaios de permeação de uma solução aquosa de KH2PO4. Independente da composição da camada filtrante, foram obtidos valores de rejeição de fosfato da ordem de 80%.Hybrid films based on poly(ethylene oxide-b-amide-6, PEBAX, and zirconium oxide were prepared by hydrolysis and condensation of zirconium tetraisopropoxide in a 3wt% PEBAX/n-butanol solution. Films were characterized by thermogravimetric analysis, differential scanning calorimetry, infrared spectroscopy and electron microscopy. The results showed that the incorporation of the inorganic phase promoted the organic polymer degradation. Composite membranes constituted by a porous support of poly(vinylidene fluoride, PVDF, covered with a PEBAX/ZrO2 filter layer were prepared and characterized by electron microscopy. Tests including the permeation of water and aqueous solutions of poly(ethylene glycol with different molecular weight were performed. Phosphate retention was also determined by permeation tests of a KH2PO4 aqueous solution. Regardless of the filter layer composition, phosphate

  15. Preparation and characterization of a Polyacrylonitrile based gel polymer electrolyte for redox capacitors

    Directory of Open Access Journals (Sweden)

    C.M. Bandaranayake

    2016-06-01

    Full Text Available In this study, a gel polymer electrolyte (GPE consisting with polyacrylonitrile (PAN, ethylene carbonate (EC, propylene carbonate (PC and magnesium trifluromethane sulfonate (Mg(CF3SO32 was prepared using the hot pressed method. The starting materials were heated at 130 oC for 2 hours and the resulting hot viscous mixture was pressed in between two well cleaned glass plates. The composition was fine-tuned by varying the salt and the polymer concentration in order to obtain a mechanically stable, thin and flexible film with a high ionic conductivity. It was found that the composition, 105 PAN : 150 MgTF : 400 EC : 400 PC gives the maximum conductivity of 1.06 x 10-2 Scm-1. DC polarization test done with blocking electrodes confirmed the ionic nature of the sample while the results obtained with non-blocking electrodes proved that the anionic contribution for the conductivity is dominant. The sample was used in redox capacitors having two identical polypyrrole electrodes doped with dodecylbenzesulfonate. Cyclic Voltammetry, Galvanostatic Charge Discharge and Electrochemical Impedance Spectroscopy techniques were used to evaluate the performance of the redox capacitors. The specific capacitance was high at low scan rates. The electrolyte was quite stable when use in the redox capacitors. Further, redox capacitor was having a good cycleability which is one of the important key issues to be considered for practical applications.

  16. Preparation and Adsorption Ability of Polysulfone Microcapsules Containing Modified Chitosan Gel

    Institute of Scientific and Technical Information of China (English)

    CHEN Fei; LUO Guangsheng; YANG Weiwei; WANG Yujun

    2005-01-01

    Chemically modified chitosan beads containing polyethyleneimine (PEI) were prepared to improve the metal ion adsorption capacity of the chitosan beads and their mechanical stability and to limit their biodegradability. The modified beads were encapsulated with the polymer material polysulfone by a novel surface coating method named the emulsion phase inversion method. The adsorption properties of the modified beads and the microstructures of the polysulfone coating layer were then analyzed. The experimental results showed that the PEI was successfully linked onto the chitosan beads. The density of the -NH2 groups in the modified beads was significantly increased, while the water content was reduced. The coating layer thickness was about 200 (m. The modified chitosan gel beads had excellent Cu(II) adsorption capacity, with a maximum Cu(II) adsorption capacity 1.34 times higher than that of the unmodified beads. The results show that even with the polysulfone coating the adsorption kinetics of the modified beads is still better than those of the unmodified beads. The modifications improve the mass transfer performance of the chitosan beads as well as the bead stability.

  17. Chirality of Single-Handed Twisted Titania Tubular Nanoribbons Prepared Through Sol-gel Transcription.

    Science.gov (United States)

    Wang, Sibing; Zhang, Chuanyong; Li, Yi; Li, Baozong; Yang, Yonggang

    2015-08-01

    Single-handed twisted titania tubular nanoribbons were prepared through sol-gel transcription using a pair of enantiomers. Handedness was controlled by that of the template. The obtained samples were characterized using field-emission electron microscopy, transmission electron microscopy, diffuse reflectance circular dichroism (DRCD), and X-ray diffraction. The DRCD spectra indicated that the titania nanotubes exhibit optical activity. Although the tubular structure was destroyed after being calcined at 700 °C for 2.0 h, DRCD signals were still identified. However, the DRCD signals disappeared after being calcined at 1000 °C for 2.0 h. The optical activity of titania was proposed to be due to chiral defects. Previous results showed that straight titania tubes could be used as asymmetric autocatalysts, indicating that titania exhibit chirality at the angstrom level. Herein, it was found that they also exhibit DRCD signals, indicating that there are no obvious relationships between morphology at the nano level and chirality at the angstrom level. The nanotube chirality should originate from the chiral defects on the nanotube inner surface. The Fourier transform infrared spectra indicated that the chirality of the titania was transferred from the gelators through the hydrogen bonding between N-H and Ti-OH. © 2015 Wiley Periodicals, Inc.

  18. Phase Composition of Samarium Niobate and Tantalate Thin Films Prepared by Sol-Gel Method

    Science.gov (United States)

    Bruncková, H.; Medvecký, Ľ.; Múdra, E.; Kovalčiková, A.; Ďurišin, J.; Šebek, M.; Girman, V.

    2017-12-01

    Samarium niobate SmNbO4 (SNO) and tantalate SmTaO4 (STO) thin films ( 100 nm) were prepared by sol-gel/spin-coating process on alumina substrates with PZT interlayer and annealing at 1000°C. The precursors of films were synthesized using Nb or Ta tartrate complexes. The improvement of the crystallinity of monoclinic M'-SmTaO4 phase via heating was observed through the coexistence of small amounts of tetragonal T-SmTa7O19 phase in STO precursor at 1000°C. The XRD results of SNO and STO films confirmed monoclinic M-SmNbO4 and M'-SmTaO4 phases, respectively, with traces of orthorhombic O-SmNbO4 (in SNO). In STO film, the single monoclinic M'-SmTaO4 phase was revealed. The surface morphology and topography of thin films were investigated by SEM and AFM analysis. STO film was smoother with roughness 3.2 nm in comparison with SNO (6.3 nm). In the microstructure of SNO film, small spherical ( 50 nm) and larger cuboidal particles ( 100 nm) of the SmNbO4 phase were observed. In STO, compact clusters composed of fine spherical SmTaO4 particles ( 20-50 nm) were found. Effect of samarium can contribute to the formation different polymorphs of these films for the application to environmental electrolytic thin film devices.

  19. Laboratory sol-gel preparation of fine fraction of sintered uranium dioxide spheres

    International Nuclear Information System (INIS)

    Landspersky, H.; Tympl, M.

    1984-01-01

    The results are summed up of the laboratory investigation of preparing the fine fraction of sintered uranium dioxide particles from uranyl gel using the method of the mixed reactor and the method of the dual-liquid nozzle, processed by leaching, drying, calcination and sintering. None of the two methods provides monodispersion particles under the given conditions but better control of the throughflow of the liquid media may improve results. Leaching of the fine fraction is very quick and the leaching of most components takes no longer than 5 minutes. In view of the fact that leaching of all components does not proceed at the same rate it is recommended that leaching time be doubled, or that leaching take place in two stages. Azeotropic distillation with chlorinated hydrocarbons is a favourable procedure for obtaining quality material; it is, however, necessary to prevent dried particles from comino. into contact with the water phase condensing on the walls of the distillation vessel and running down onto the surface of the distilling mixture. Calcination at a temperature of 500 degC in a thin layer and sintering at temperatures between 1350 and 1550 degC at an adequate rate of inflow of gaseous media and adequate rate of outflow of reaction wastes results in the production of high quality material whose density exceeds 97 to 98% theoretical density. (author)

  20. Phase study of titanium dioxide nanoparticle prepared via sol-gel process

    Science.gov (United States)

    Oladeji Araoyinbo, Alaba; Bakri Abdullah, Mohd Mustafa Al; Salleh, Mohd Arif Anuar Mohd; Aziz, Nurul Nadia Abdul; Iskandar Azmi, Azwan

    2018-03-01

    In this study, titanium dioxide nanoparticles have been prepared via sol-gel process using titanium tetraisopropoxide as a precursor with hydrochloric acid as a catalyst, and ethanol with deionized water as solvents. The value of pH used is set to 3, 7 and 8. The sols obtained were dried at 100 °C for 1 hr and calcined at 350, 550, and 750 °C for 3 hrs to observe the phase transformation of titanium dioxide nanoparticle. The samples were characterized by x-ray diffraction and field emission scanning electron microscope. The morphology analysis is obtained from field emission scanning electron microscope. The phase transformation was investigated by x-ray diffraction. It was found that the pH of the solution affect the agglomeration of titanium dioxide particle. The x-ray diffraction pattern of titanium dioxide shows the anatase phase most abundant at temperature of 350 °C. At temperature of 550 °C the anatase and rutile phase were present. At temperature of 750 °C the rutile phase was the most abundant for pH 3, 7 and 8. It was confirmed that at higher temperature the rutile phase which is the stable phase are mostly present.

  1. Oxidizing gel formulation for nuclear decontamination: rheological and acidic properties of the organic matrix and its ozonolysis

    International Nuclear Information System (INIS)

    Rouy, E.

    2003-10-01

    An acidic and oxidizing gel was formulated with a purely organic matrix, xanthan gum, at low concentrations (1 to 2 wt %). This polymer gel was investigated in various media (aqueous, acidic and ceric) by means of rheology: shear thinning behaviour, thixotropy, yield stress... Evidences of unexpected rheological properties in highly concentrated media show that xanthan is quite convenient for industrial projection of this type of gel on metallic walls in nuclear plants, notwithstanding its time-limited resistance to oxidation (about a few hours). Complexation mechanisms between ceric species and polar sites of the polymer led us to characterise acidic properties of our xanthan sample by potentiometric titration and 1 H NMR techniques. The matrix was finally treated by ozonolysis to suppress organic residues, as required to handle nuclear wastes. In acidic medium, ozonolysis of the gel was achieved successfully while in acidic and ceric medium this process showed limited efficiency, needing further investigation to be clarified. (author)

  2. Properties of Zn O/Cr thin films prepared by Sol-Gel; Propiedades de peliculas delgadas ZnO/Cr preparadas por Sol-Gel

    Energy Technology Data Exchange (ETDEWEB)

    Tirado G, S.; Olvera A, R., E-mail: tirado@esfm.ipn.mx [IPN, Escuela Superior de Fisica y Matematicas, Edificio 9, Unidad Profesional A. L. M., San Pedro Zacatenco, 07788 Mexico D. F. (Mexico)

    2014-08-15

    Zn O films and those superficially modified with chromium were deposited on substrates of soda-lime glass, using the Sol-Gel process and the repeated immersion method. Starting from dehydrated zinc acetate was prepared a solution to 0.6 M to ambient temperature in 2-methoxyethanol and monoethanolamine (Mea) stirring magnetically. The Sol was prepared with an aging to seven days and was used to grow a films group with thickness to eight immersions. These same films were superficially modified with several depositions of a chromium nitrate Sol dissolved in ethanol to low concentration. The Zn O films were structurally characterized by X-ray diffraction, its chemical composition by energy dispersive X-ray spectroscopy and its morphology by scanning electron microscopy and atomic force microscopy, as well as their optical properties by UV-vis. Of the obtained results are proposed possible applications. (author)

  3. Luminescence of Eu(3+) doped SiO2 Thin Films and Glass Prepared by Sol-gel Technology

    Science.gov (United States)

    Castro, Lymari; Jia, Weiyi; Wang, Yanyun; Santiago, Miguel; Liu, Huimin

    1998-01-01

    Trivalent europium ions are an important luminophore for lighting and display. The emission of (5)D0 to (7)F2 transition exhibits a red color at about 610 nm, which is very attractive and fulfills the requirement for most red-emitting phosphors including lamp and cathode ray phosphorescence materials. Various EU(3+) doped phosphors have been developed, and luminescence properties have been extensively studied. On the other hand, sol-gel technology has been well developed by chemists. In recent years, applications of this technology to optical materials have drawn a great attention. Sol-gel technology provides a unique way to obtain homogeneous composition distribution and uniform doping, and the processing temperature can be very low. In this work, EU(3+) doped SiO2 thin films and glasses were prepared by sol-gel technology and their spectroscopic properties were investigated.

  4. Preparation and utilization of metal oxide fine powder

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joon Soo; Jang, Hee Dong; Lim, Young Woong; Kim, Sung Don; Lee, Hi Sun; Lee, Hoo In; Kim, Chul Joo; Shim, Gun Joo; Jang, Dae Kyu [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    Metal oxide fine powders finds many applications in industry as new materials. It is very much necessary for the development of such powders to improve the domestic industry. The purpose of present research is to develop a process for the preparation and utilization of metal oxide fine powder. This project is consisted of two main subjects. (1) Production of ultrafine metal oxide powder: Ultrafine metal oxide powder is defined as a metal oxide powder of less than 100 nanometer in particle size. Experiments for the control of particle size and distributions in the various reaction system and compared with results of (2 nd year research). Various reaction systems were adopted for the development of feasible process. Ultrafine particles could be prepared even higher concentration of TiCl{sub 4} and lower gas flowrate compared to TiCl{sub 4}-O{sub 2} system in the TiCl{sub 4}-Air-H{sub 2}O system. Ultrafine Al{sub 2}O{sub 3} powders also prepared with the change of concentration and gas flowrate. Experiments on the treatment of surface characteristics of ultrafine TiO{sub 2} powders were investigated using esterification and surface treating agents. A mathematical model that can predict the particle size and distribution was also developed. (2) Preparation of cerium oxide for high-grade polishing powder: Used cerium polishing powder was recycled for preparation of high grade cerium oxide polishing powder. Also, cerium hydroxide which was generated as by-product in processing of monazite ore was used as another material. These two materials were leached respectively by using acid, and the precipitate was gained in each leached solution by adjusting pH of the solution, and by selective crystallization. These precipitates were calcined to make high grade cerium oxide polishing powder. The effect of several experimental variables were investigated, and the optimum conditions were obtained through the experiments. (author). 81 refs., 49 figs., 27 tabs.

  5. Preparation and characterization of polyindole - iron oxide nanocomposite electrolyte

    International Nuclear Information System (INIS)

    Rajasudha, G.; Stephen, A.; Narayanan, V.

    2009-01-01

    Full text: A novel polyindole-iron oxide containing LiClO 4 solid polymer electrolyte has been prepared. The diverse property of magnetic nanoparticle has elicited wide interest from the point of view of technological applications. Their properties are known to be strongly dependent on size, anisotropy and inter particle interactions. The proton conducting materials has received considerable attention as electrolyte materials in technological applications such as fuel cells, sensors and electrochromic display. In this work, polyindole-iron oxide nanocomposite containing LiClO 4 was prepared by in situ polymerization. The indole was polymerized in the presence of iron oxide, using ammonium peroxy disulphate as an oxidizing agent. The polyindole-iron oxide nanocomposite was characterized by XRD, IR, SEM, TGA and TEM. The iron oxide nano particles was incorporated into polyindole and was confirmed by XRD and Fourier transform infrared (FTIR) spectroscopy. The surface Morphology and thermal stability were studied by thermogravimetric analysis (TGA) and SEM respectively. The ionic conductivity of polyindole electrolyte was analyzed from impedance spectrum. The prepared polyindole-iron oxide nanocomposite could be used as solid electrolyte in lithium ion batteries

  6. Preparative-scale separation of C60 and C70 on polystyrene gel

    International Nuclear Information System (INIS)

    Guegel, A.; Becker, M.; Hammel, D.; Mindach, L.; Raeder, J.; Simon, T.; Wagner, M.; Muellen, K.

    1992-01-01

    Five grams of a mixture of C 60 /C 70 can be separated in 24 hours by gel permeation chromatography on polystyrene gel. The mobile phase can be completely recovered, and the method can be scaled up by a simple increase in the inner diameter of the column. (orig.) [de

  7. Preparation of chitosan-graft-(β-cyclodextrin) based sol-gel stationary phase for open-tubular capillary electrochromatography.

    Science.gov (United States)

    Lü, Haixia; Li, Qingyin; Yu, Xiaowei; Yi, Jiaojiao; Xie, Zenghong

    2013-07-01

    A novel open-tubular CEC column coated with chitosan-graft-(β-CD) (CDCS) was prepared using sol-gel technique. In the sol-gel approach, owing to the 3D network of sol-gel and the strong chemical bond between the stationary phase and the surface of capillary columns, good chromatographic characteristics and unique selectivity in separating isomers were shown. The column efficiencies of 55,000∼163,000 plates/m for the isomeric xanthopterin and phenoxy acid herbicides using the sol-gel-derived CDCS columns were achieved. Good stabilities were demonstrated that the RSD values for the retention time of thiourea and isoxanthopterin were 1.3 and 1.4% (run to run, n = 5), 1.6 and 2.0% (day to day, n = 3), 2.9 and 3.1% (column to column, n = 3), respectively. The sol-gel-coated CDCS columns have shown improved separations of isomeric xanthopterin in comparison with CDCS-bonded capillary column. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Sol-gel preparation of high surface area potassium tetratitanate for the immobilization of nuclear waste metal ions

    International Nuclear Information System (INIS)

    Jung, K.T.; Shul, Y.G.; Moon, J.K.; Oh, W.J.

    1997-01-01

    Potassium tetratinates(K 2 Ti 4 O 9 ) were synthesized by using the sol-gel method to produce ion-exchangeable materials with high surface area. The effects of mole ratios of K/Ti and H 2 O/Ti were examined. K 2 Ti 4 O 9 was obtained at 740 deg. C by the sol-gel method, which uses a lower temperature than the melting method. After calcination at 800 deg. C, K 2 Ti 4 O exhibits a needle shape which is quite different from the shape of K 2 Ti 6 O 13 powder. The surface areas of K 2 Ti 4 O 9 was 15 m 2 /g by the sol-gel method after calcining at 800 C. The enhancement of BET area to 25 m 2 /g was obtained after supercritical drying using EtOH as solvent. By using the sodium alginate method, needle type potassium titanate 10μm in length, the longest aspect ratio of 1,3 x 10 3 could be obtained. There are variations in the Sr 2+ ion exchange rate and capacity according to the preparation method. Larger BET surface area provides fast ion exchange and larger capacity for Sr 2+ ion in the order; sol-gel process with supercritical drying > sol-gel process > melting process. (author). 17 refs, 21 figs, 1 tab

  9. Preparation and use of chemically modified MCM-41 and silica gel as selective adsorbents for Hg(II) ions

    International Nuclear Information System (INIS)

    Puanngam, Mahitti; Unob, Fuangfa

    2008-01-01

    Adsorbents for Hg(II) ion extraction were prepared using amorphous silica gel and ordered MCM-41. Grafting with 2-(3-(2-aminoethylthio)propylthio)ethanamine was used to functionalize the silica. The functionalized adsorbents were characterized by nitrogen adsorption, X-ray diffraction, 13 C MAS NMR spectroscopy and thermogravimetric analysis. The adsorption properties of the modified silica gel and MCM-41 were compared using batch method. The effect of pH, stirring time, ionic strength and foreign ions were studied. The extraction of Hg(II) ions occurred rapidly with the modified MCM-41 and the optimal pH range for the extraction by the modified materials was pH 4-7. Foreign ions, especially Cl - had some effect on the extraction efficiency of the modified silica gel and the modified MCM-41. The adsorption behavior of both adsorbents could be described by a Langmuir model at 298 K, and the maximum adsorption capacity of the modified silica gel and MCM-41 at pH 3 was 0.79 and 0.70 mmol g -1 , respectively. The modified MCM-41 showed a larger Langmuir constant than that of the modified silica gel, indicating a better ability for Hg(II) ion adsorption. The results indicate that the structure of the materials affects the adsorption behavior. These materials show a potential for the application as effective and selective adsorbents for Hg(II) removal from water

  10. Analysis of purified gp96 preparations from rat and mouse livers using 2-D gel electrophoresis and tandem mass spectrometry.

    Science.gov (United States)

    Fairburn, B; Muthana, M; Hopkinson, K; Slack, L K; Mirza, S; Georgiou, A S; Espigares, E; Wong, C; Pockley, A G

    2006-09-01

    The stress protein gp96 exhibits a number of immunological activities, the majority of studies into which have used gp96 purified from a variety of tissues. On the basis of 1-D gel electrophoresis, the purity of these preparations has been reported to range between 70% and 99%. This study analyzed gp96 preparations from rat and mouse livers using 2-D gel electrophoresis and liquid chromatography electrospray ionization tandem mass spectrometry (MS-MS). The procedure for purifying gp96 was reproducible, as similar protein profiles were observed in replicate gels of gp96 preparations. The purity of the preparations was typically around 70%, with minor co-purified proteins of varying molecular weights and mobilities being present. Dominant bands at 95-100 kDa in preparations from Wistar rats and C57BL/6 mice were identified as gp96 by ECL Western blotting. Multiple bands having similar, yet distinct molecular weights and differing pI mobility on ECL Western blots were confirmed as being gp96 in preparations from Wistar rats using MS-MS. The most striking feature of the 2-D gel analysis was the presence of additional dominant bands at 55 kDa in preparations from Wistar rats, and at 75-90 kDa in preparations from C57BL/6 mice. These were identified as gp96 by ECL Western blotting and, in the case of preparations from Wistar rats, by MS-MS. Although the lower molecular weight, gp96-related molecules might be partially degraded gp96, their reproducible presence, definition and characteristics suggest that they are alternative, species-specific isoforms of the molecule. A 55 kDa protein which exhibited a lower pI value than gp96 was present in all preparations and this was identified as calreticulin, another putative immunoregulatory molecule. This study confirms the reproducibility of the gp96 purification protocol and reveals the presence of multiple gp96 isoforms, some of which likely result from post-translational modifications such as differential glycosylation and

  11. Thin TiO2 Films Prepared by Inkjet Printing of the Reverse Micelles Sol-Gel Composition

    Czech Academy of Sciences Publication Activity Database

    Morozová, Magdalena; Klusoň, Petr; Krýsa, Josef; Dzik, P.; Veselý, M.; Šolcová, Olga

    2011-01-01

    Roč. 160, č. 1 (2011), s. 371-378 ISSN 0925-4005 R&D Projects: GA ČR GD203/08/H032; GA ČR GA104/09/0694; GA AV ČR KAN400720701 Institutional research plan: CEZ:AV0Z40720504 Keywords : sol-gel * titanium oxide * inkjet printing Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.898, year: 2011

  12. Preparation and Characterization of Tin Oxide Nanowires

    Directory of Open Access Journals (Sweden)

    A. Kabiri

    2013-12-01

    Full Text Available The aim of this research is preparation of SnO2 nanowires by means of Thermal chemical reaction vapor transport deposition (TCRVTD method from SnO powders. The morphology, chemical composition and microstructure properties of the nanowires are characterized using field emission scanning electron microscope (FE-SEM, EDS, and XRD. The XRD diffraction patterns reveal that the SnO2 nanowires have been grown in the form of tetragonal crystal structures with the lattice parameter of a=b=0.440 nm, and c=0.370 nm. The SEM images reveal that SnO2 nanowires have successfully been grown on the Si substrate. The EDS patterns show that only elements of Sn, O and Au are detected. Prior to the VLS process the substrate is coated by a thin layer of Au. The diameter of nanowires is measured to be something between 20-100 nm.

  13. The effect of linker of electrodes prepared from sol–gel ionic liquid precursor and carbon nanoparticles on dioxygen electroreduction bioelectrocatalysis

    International Nuclear Information System (INIS)

    Szot, Katarzyna; Lynch, Robert P.; Lesniewski, Adam; Majewska, Ewa; Sirieix-Plenet, Juliette; Gaillon, Laurent; Opallo, Marcin

    2011-01-01

    The effect of linker of three-dimensional, hydrophilic-carbon-nanoparticle film-electrodes prepared by layer-by-layer method on redox probe accumulation and bioelectrocatalytic dioxygen reduction was studied and compared for two different electrode scaffolds. The linker in both of these scaffolds was based on the same ionic liquid sol–gel precursor, 1-methyl-3-(3-trimethoxysilylpropyl) imidazolium bis(trifluoromethyl-sulfonyl)imide. The first electrode type was prepared by alternative immersion of tin doped indium oxide substrate in an aqueous suspension of carbon nanoparticles modified with phenyl sulphonic groups and a sol composed of ionic liquid sol–gel precursor and tetramethoxysilane. For the second electrode type sol was replaced by a methanolic suspension of silicate submicroparticles with appended imidazolium functional groups. In both films 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) anions accumulate irreversibly. In the case of the first electrode electrostatic attraction plays the more important role in comparison to the case of the second where stable adsorption of the redox probe takes place. After adsorption of bilirubin oxidase, electrodes obtained from sol and carbon nanoparticles exhibit modest bioelectrocatalytic activity towards dioxygen reduction at pH 4.8, however those obtained from oppositely charged particles are much more efficient. The magnitude of the associated catalytic current in both cases depends on the number of immersion and withdrawal steps. Interestingly, mediatorless catalysis at electrodes obtained from oppositely charged particles is more efficient than mediated catalysis.

  14. Boron cross-linked graphene oxide/polyvinyl alcohol nanocomposite gel electrolyte for flexible solid-state electric double layer capacitor with high performance

    KAUST Repository

    Huang, Yi-Fu; Wu, Peng-Fei; Zhang, Ming-Qiu; Ruan, Wen-Hong; Giannelis, Emmanuel P.

    2014-01-01

    A new family of boron cross-linked graphene oxide/polyvinyl alcohol (GO-B-PVA) nanocomposite gels is prepared by freeze-thaw/boron cross-linking method. Then the gel electrolytes saturated with KOH solution are assembled into electric double layer capacitors (EDLCs). Structure, thermal and mechanical properties of GO-B-PVA are explored. The electrochemical properties of EDLCs using GO-B-PVA/KOH are investigated, and compared with those using GO-PVA/KOH gel or KOH solution electrolyte. FTIR shows that boron cross-links are introduced into GO-PVA, while the boronic structure inserted into agglomerated GO sheets is demonstrated by DMA analysis. The synergy effect of the GO and the boron crosslinking benefits for ionic conductivity due to unblocking ion channels, and for improvement of thermal stability and mechanical properties of the electrolytes. Higher specific capacitance and better cycle stability of EDLCs are obtained by using the GO-B-PVA/KOH electrolyte, especially the one at higher GO content. The nanocomposite gel electrolytes with excellent electrochemical properties and solid-like character are candidates for the industrial application in high-performance flexible solid-state EDLCs. © 2014 Elsevier Ltd.

  15. Boron cross-linked graphene oxide/polyvinyl alcohol nanocomposite gel electrolyte for flexible solid-state electric double layer capacitor with high performance

    KAUST Repository

    Huang, Yi-Fu

    2014-06-01

    A new family of boron cross-linked graphene oxide/polyvinyl alcohol (GO-B-PVA) nanocomposite gels is prepared by freeze-thaw/boron cross-linking method. Then the gel electrolytes saturated with KOH solution are assembled into electric double layer capacitors (EDLCs). Structure, thermal and mechanical properties of GO-B-PVA are explored. The electrochemical properties of EDLCs using GO-B-PVA/KOH are investigated, and compared with those using GO-PVA/KOH gel or KOH solution electrolyte. FTIR shows that boron cross-links are introduced into GO-PVA, while the boronic structure inserted into agglomerated GO sheets is demonstrated by DMA analysis. The synergy effect of the GO and the boron crosslinking benefits for ionic conductivity due to unblocking ion channels, and for improvement of thermal stability and mechanical properties of the electrolytes. Higher specific capacitance and better cycle stability of EDLCs are obtained by using the GO-B-PVA/KOH electrolyte, especially the one at higher GO content. The nanocomposite gel electrolytes with excellent electrochemical properties and solid-like character are candidates for the industrial application in high-performance flexible solid-state EDLCs. © 2014 Elsevier Ltd.

  16. Preparation and study of properties of dispersed graphene oxide

    Directory of Open Access Journals (Sweden)

    Evgeniya Seliverstova

    2015-09-01

    Full Text Available Ability of graphene oxide to form stable dispersion in organic solvents was studied in this work. As it was shown, sonication of graphene leads to the decreas of the particle size. Stability of prepared graphene dispersions was studied upon measurements of distribution of number of the particles via size and change of optical density of the solutions with time. It was found that graphene oxide forms a more stable dispersion in tetrahydrofuran and dimethylformamide than in chloroform and acetone.

  17. Preparation and characterization of antimony barium composite oxide photocatalysts

    Science.gov (United States)

    Han, X. P.; Yao, B. H.; Pan, Q. H.; Pen, C.; Zhang, C. L.

    2018-01-01

    In this paper, two kinds of antimony barium composite oxide photocatalysts have been prepared by two methods and characterized by XRD and SEM. The photocatalytic activity was evaluated by a photocatalytic reactor and an ultraviolet spectrophotometer. The results showed that-BaSb2O5•4H2O, BaSb2O6 two kinds of antimony barium composite oxide photocatalysts were successfully prepared in this experiment and they showed good photocatalytic properties. In addition, BaSb2O6 morphology showed more regular, microstructure and better catalytic performance.

  18. Synthesis and studies of Y-Ba-Cu-O high temperature superconductor prepared by sol-gel method

    International Nuclear Information System (INIS)

    Grigoryan, S.G.; Manukyan, A.L.; Hayrapetyan, A.G.; Arzumanyan, A.M.; Rashidyan, L.H.; Mkrtichyan, N.Y.; Mkrtchyan, A.A.; Kurginyan, K.A.; Trozyan, A.H.; Vardanyan, R.S.

    2004-01-01

    The method of preparation of Y-Ba-Cu-O high temperature superconducting materials by sol-gel processing technique both for powders and thin films are described. All these methods are based on using yttrium alkoxides as precursors, which are not ready available reagents, besides the majority of these methods use copper alkoxides, which show low solubility in organic solvents, moreover they are very sensitive to hydrolysis in air. The new method of preparation of Y-Ba-Cu-O ceramic materials by sol-gel processing technique based on new and convenient precursors stable in air, having high compatibility with each other is offered. Basic scientific and technological issues related to the synthesis of bulk materials, their structure and electrical conductivity are discussed

  19. Sol-gel preparation of lead magnesium niobate (PMN) powders and thin films

    Science.gov (United States)

    Boyle, T.J.

    1999-01-12

    A method of preparing a lead magnesium niobium oxide (PMN), Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}, precursor solution by a solvent method wherein a liquid solution of a lead-complex PMN precursor is combined with a liquid solution of a niobium-complex PMN precursor, the combined lead- and niobium-complex liquid solutions are reacted with a magnesium-alkyl solution, forming a PMN precursor solution and a lead-based precipitate, and the precipitate is separated from the reacted liquid PMN precursor solution to form a precipitate-free PMN precursor solution. This precursor solution can be processed to form both ferroelectric powders and thin films. 3 figs.

  20. Preparation of Reduced Graphene Oxides as Electrode Materials for Supercapacitors

    KAUST Repository

    Bai, Yaocai

    2012-06-01

    Reduced graphene oxide as outstanding candidate electrode material for supercapacitor has been investigated. This thesis includes two topics. One is that three kinds of reduced graphene oxides were prepared by hydrothermal reduction under different pH conditions. The pH values were found to have great influence on the reduction of graphene oxides. Acidic and neutral media yielded reduced graphene oxides with more oxygen-functional groups, lower specific surface areas but broader pore size distributions than those in basic medium. Variations induced by the pH changes resulted in great differences in the supercapacitor performance. The graphene produced in the basic solution presented mainly electric double layer behavior with specific capacitance of 185 F/g, while the other two showed additional pseudocapacitance behavior with specific capacitance of 225 F/g (acidic) and 230 F/g (neutral), all at a constant current density of 1A/g. The other one is that different reduced graphene oxides were prepared via solution based hydrazine reduction, low temperature thermal reduction, and hydrothermal reduction. The as- prepared samples were then investigated by UV-vis spectroscopy, X-ray diffraction, Raman spectroscopy, and Scanning electron microscope. The supercapacitor performances were also studied and the hydrothermally reduced graphene oxide exhibited the highest specific capacitance.

  1. Preparation and evaluation of chitosan-based nanogels/gels for oral delivery of myricetin.

    Science.gov (United States)

    Yao, Yashu; Xia, Mengxin; Wang, Huizhen; Li, Guowen; Shen, Hongyi; Ji, Guang; Meng, Qianchao; Xie, Yan

    2016-08-25

    A novel nanogel/gel based on chitosan (CS) for the oral delivery of myricetin (Myr) was developed and evaluated comprehensively. The particle size of the obtained Myr-loaded CS/β-glycerol phosphate (β-GP) nanogels was in the range of 100-300nm. The rheological tests showed that the sol-gel transition happened when the nanogels were exposed to physiological temperatures, and 3D network structures of the gelatinized nanogels (gels) were confirmed by Scanning Electron Microscopy. Myr was released from CS/β-GP nanogel/gel in acidic buffers via a Fickian mechanism, and this release was simultaneously accompanied by swelling and erosion. Moreover, the nanogel/gel exhibited no cytotoxicity by MTT assay, and the oral bioavailability of Myr in rats was improved with an accelerated absorption rate after Myr was loaded into CS/β-GP nanogel/gel. In summary, all of the above showed that CS/β-GP nanogel/gel was an excellent system for orally delivering Myr. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Processing and mechanical behavior of Nicalon{reg_sign}/SiC composites with sol-gel derived oxide interfacial coatings

    Energy Technology Data Exchange (ETDEWEB)

    Shanmugham, S.; Liaw, P.K. [Tennessee Univ., Knoxville, TN (United States). Dept. of Materials Science and Engineering

    1996-10-01

    Recent analytical and finite element modeling studies have indicated that low modulus interface materials are desirable for obtaining Nicalon/SiC composites with good toughness. Two oxides, Al titanate and mullite, were chosen on this basis as interface materials. The oxide and C coatings were deposited by sol-gel and CVD, respectively. Nicalon/SiC composites with oxide/C and C/oxide/C interfaces were fabricated and evaluated for flexure strength in the as-processed and oxidized conditions. Composites with C/oxide/C interfaces retained considerable strength and damage-tolerant behavior even after 500 h oxidation at 1000 C in air. The C/oxide/C interface shows promise as a viable oxidation-resistant interface alternative to C or BN interfaces.

  3. Methods of preparing deposits containing iron oxides for recycling

    Directory of Open Access Journals (Sweden)

    T. Lis

    2013-04-01

    Full Text Available The metallurgical industry is one of the largest sources of wastes. Some of them, however, owing to their content of metals such as zinc or iron, may become valuable secondary raw materials. In order to achieve that purpose, they require appropriate preparation. This article provides a discussion on the methods of preparation of scrap from steelworks, namely deposits containing iron oxides, enabling their recycling.

  4. Preparation of ZrW{sub 2}O{sub 8} xerogel and aerogels by sol-gel chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Noailles, L.; Dunn, B.; Larson, D. [Dept. of Materials Science and Engineering, Univ. of California, Los Angeles, CA (United States); Starkovich, J.; Peng, H. [Northrop Grumman Space Technology, Redondo Beach, CA (United States)

    2004-07-01

    Xerogels and aerogels with the composition ZrW{sub 2}O{sub 8} have been synthesized using sol-gel chemistry. For the xerogel, trigonal phase is formed at 650 C and the cubic phase forms above 1100 C in less than 30 seconds. Aerogels have been prepared with an average pore diameter of 110 Aa and a surface area of 510 m{sup 2}g{sup -1}. (orig.)

  5. Synthesis of NiO–Al{sub 2}O{sub 3} nanocomposites by sol–gel process and their use as catalyst for the oxidation of styrene

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Sudheer Kumar; Jeevanandam, P., E-mail: jeevafcy@iitr.ac.in

    2014-10-15

    Highlights: • NiO–Al{sub 2}O{sub 3} nanocomposites have been synthesized by sol–gel method. • The synthesis takes shorter time (∼48 h) compared to reported methods. • The nanocomposites show high catalytic activity for the oxidation of styrene compared to NiO. - Abstract: NiO–Al{sub 2}O{sub 3} nanocomposites were prepared by sol–gel method. The synthesized nanocomposites were characterized by X-ray diffraction, FT-IR spectroscopy, Raman spectroscopy, field emission scanning electron microscopy coupled with energy dispersive X-ray analysis, transmission electron microscopy, diffuse reflectance spectroscopy and magnetic measurements. XRD results indicate that the NiO–Al{sub 2}O{sub 3} nanocomposites consist of small NiO crystallites (mean size ∼2.6 nm). TEM results indicate uniform distribution of NiO nanoparticles in the Al{sub 2}O{sub 3} matrix. Increase in the band gap of NiO in the nanocomposites compared to pure NiO nanoparticles is observed and the nanocomposites show superparamagnetic behaviour. The NiO–Al{sub 2}O{sub 3} nanocomposites show high catalytic activity for the oxidation of styrene using tert-butyl hydroperoxide as the oxidant and also show higher selectivity for styrene oxide with higher total conversion compared to pure NiO nanoparticles.

  6. Nanostructured ZnO thin films prepared by sol–gel spin-coating

    Energy Technology Data Exchange (ETDEWEB)

    Heredia, E., E-mail: heredia.edu@gmail.com [UNIDEF (CONICET-MINDEF), J.B. de La Salle 4397, 1603 Villa Martelli, Pcia. de Buenos Aires (Argentina); Bojorge, C.; Casanova, J.; Cánepa, H. [UNIDEF (CONICET-MINDEF), J.B. de La Salle 4397, 1603 Villa Martelli, Pcia. de Buenos Aires (Argentina); Craievich, A. [Instituto de Física, Universidade de São Paulo, Cidade Universitária, 66318 São Paulo, SP (Brazil); Kellermann, G. [Universidade Federal do Paraná, 19044 Paraná (Brazil)

    2014-10-30

    Highlights: • ZnO films synthesized by sol–gel were deposited by spin-coating on flat substrates. • Structural features of ZnO films with several thicknesses were characterized by means of different techniques. • The thicknesses of different ZnO thin films were determined by means of FESEM and AFM. • The nanoporous structures of ZnO thin films were characterized by GISAXS using IsGISAXS software. • The average densities of ZnO thin films were derived from (i) the critical angle in 1D XR patterns, (ii) the angle of Yoneda peak in 2D GISAXS images, (iii) minimization of chi2 using IsGISAXS best fitting procedure. - Abstract: ZnO thin films deposited on silica flat plates were prepared by spin-coating and studied by applying several techniques for structural characterization. The films were prepared by depositing different numbers of layers, each deposition being followed by a thermal treatment at 200 °C to dry and consolidate the successive layers. After depositing all layers, a final thermal treatment at 450 °C during 3 h was also applied in order to eliminate organic components and to promote the crystallization of the thin films. The total thickness of the multilayered films – ranging from 40 nm up to 150 nm – was determined by AFM and FESEM. The analysis by GIXD showed that the thin films are composed of ZnO crystallites with an average diameter of 25 nm circa. XR results demonstrated that the thin films also exhibit a large volume fraction of nanoporosity, typically 30–40 vol.% in thin films having thicknesses larger than ∼70 nm. GISAXS measurements showed that the experimental scattering intensity is well described by a structural model composed of nanopores with shape of oblate spheroids, height/diameter aspect ratio within the 0.8–0.9 range and average diameter along the sample surface plane in the 5–7 nm range.

  7. Study of gels of molybdenum with cerium in the preparation of generators of 99Mo - 99mTc

    Directory of Open Access Journals (Sweden)

    Vanessa Moraes

    2005-10-01

    Full Text Available 99mTc has ideal nuclear properties for organ imaging in nuclear medicine, and it is obtained from the 99Mo-99mTc generator. Four different types of generators are available: chromatographic that uses 99Mo from fission of uranium; MEK solvent extraction; Tc2O7 sublimation; gel chromatographic. This work presents the preparation of gel generators of molybdenum with cerium and characterization of the gels: mass ratio between molybdenum and cerium, structure, size of particles and elution percentage of 99mTc after irradiating the gels. Eight gels were prepared at the same temperature of 50 ºC with concentrations of NaOH of 2 and 4 mol/L, mass ratio of 0.31 and 0.38 and final pH of 3.5 and 4.5. The analysis of the results proved that these gels are not adequate for preparation of the generators of 99Mo-99mTc, since the elution percentages are low, when compared with the gel of molybdenum with zirconium.O 99mTc é o radiofármaco mais utilizado em Medicina Nuclear. Ele é obtido do gerador de 99Mo-99mTc e existem quatro tipos diferentes de geradores: cromatográfico que utiliza 99Mo de fissão; extração por solvente com MKT; sublimação do heptaóxido de tecnécio; cromatográfico tipo gel. Este trabalho apresenta a preparação de geradores tipo gel de molibdênio com cério, a caracterização desses géis com relação à quantidade de molibdênio e de cério, sua estrutura, tamanho das partículas e porcentagem de eluição do 99mTc após o gel ser irradiado. Foram preparados oito géis na temperatura de 50ºC com concentração de NaOH de 2 e 4 mol/L, relação de massa de 0,31 e 0,38 e pH final de 3,5 e 4,5. A análise dos resultados comprovou que esses géis não são adequados para preparação dos geradores de 99Mo-99mTc, já que as porcentagens de eluição são baixas, quando comparadas com o gel de molibdênio com zircônio.

  8. Preparation and characterization of ultrafine alumina via sol-gel polymeric route

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, D.M. [Ceramic Department, National Research Centre, Dokki, Cairo (Egypt); Abu-Ayana, Y.M. [Polymers and Pigments Department, National Research Centre, Dokki, Cairo (Egypt)], E-mail: yosreya20@gmail.com

    2008-10-15

    Ultrafine alumina powder was prepared through resin formation between urea and formaldehyde. Aluminium stearate soap was introduced during resin preparation. Ethylene glycol was used to terminate the thermosetting reaction. Calcination of the product was carried out at 700, 1000, 1100, 1300 and 1400 deg. C to obtain aluminium oxide. IR and Raman spectroscopic analysis indicated the occupation of Al{sup 3+} at different sites in the polymer network (C=O, -NH{sub 2}, C-O, -NH, and -CH{sub 2}OH). X-ray diffraction of powder calcined at 1000 deg. C revealed the presence of a mixture of {alpha}- and {theta}-alumina together, while a mixture of {alpha}- and {beta}-alumina phases were obtained on calcination at 1400 deg. C. Transmission electron microscope (TEM) examination of the powder fired at 700 deg. C showed uniform grains in the form of clusters with average size between 22.02 and 30.5 nm. Clusters are multi-particles as evident from the electron diffraction pattern. Crystallite size of alumina powder calcined at 1000 deg. C was found to be {approx}25.67 nm, while that of powder calcined at1400 deg. C was {approx}30.52 nm. The calculated specific surface area of alumina powder calcined at 1000 deg. C was 59.17 m{sup 2} g{sup -1}, while that calcined at 1400 deg. C was 49.77 m{sup 2} g{sup -1}.

  9. Preparation, characterization and antibacterial activity of oxidized κ-carrageenan.

    Science.gov (United States)

    Zhu, Mingjin; Ge, Liming; Lyu, Yongbo; Zi, Yaxin; Li, Xinying; Li, Defu; Mu, Changdao

    2017-10-15

    The oxidized κ-carrageenans with different oxidation levels were prepared through the hydrogen peroxide and copper sulfate redox system. The oxidation level of oxidized κ-carrageenan was successfully controlled by adjusting the dosage of hydrogen peroxide. The results showed that the microtopography of oxidized κ-carrageenan changed from rough granules to smooth flakes, mainly resulting from the easily melting property of oxidized κ-carrageenan induced by introduced carboxyl and aldehyde groups. Especially, the antibacterial activity of oxidized κ-carrageenans against Gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) was systematically investigated. The results showed that the oxidized κ-carrageenan could damage the bacterial cell wall and cytoplasmic membrane and suppress the growth of both Gram-positive and Gram-negative bacteria. The oxidized κ-carrageenan possessed broad-spectrum antibacterial activity, which may be used as a new antibacterial agent. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Preparation of the FXG gel dosemeter and studying its response for low and medium energy X-rays

    International Nuclear Information System (INIS)

    Bero, M.; Kharita, M. H.

    2008-02-01

    Gel dosimetry method was found to be capable of addressing complicated issues related to dose measurements particularly in modern sophisticated radiotherapy applications. Ferrous-sulphate Xylenol-orange and Gelatin (FXG) radiochromic gel dosemeter is one of the systems used for such applications. Some chemical dosemeters show different response for low and medium energies X-rays in comparison with high energy-photons. The energy and dose rate dependence of the FXG dose response was examined. In addition to the detector response other important dosimetric properties of the system were investigated for different X-ray beam qualities with tube voltages in the range 100 - 300 kv. An orthovoltage X-ray therapy unit was used to irradiate standard sized samples of FXG from different batches for radiation doses in the range 0 - 8 Gy. This work includes in the first stage the preparation of the radiochromic gel dosemeter (FXG) as well as its calibration in gamma radiation field. Furthermore, the stability and reproducibility of measurements were tested. The obtained results were found to be suitable as a basis to carry on the next stage of this study. The second phase was centred about the delivery of radiation doses from X-ray source that has increasing energy and evaluating the gel material properties as a dosemeter in this case, with concentration on finding the changes of the gel material response with the changes in the applied X-ray energy. Therefore establishing the response radiation energy dependence and comparing the measurement results with other results taken from other known dosimetry system such as ion chambers. Experiments shows that the FXG gel detector has a dynamic rage suitable for the dose delivered in radiotherapy treatment; its response as a function of the dose rate is also stable in the range of radiation energies applied.(Author)

  11. Preparation of Nd-doped gadolinium-gallium garnet laser ceramic powder by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    YAO Yan-ping; LIU Jing-he

    2006-01-01

    Preparation of Nd3+:Gd3Ga5O12 polycrystalline material by sol-gel method was preparated in this paper.The structure and the pattern of the sample were analyzed by thermogravimetric analysis and differential thermal analysis(TG-DTA),Infrared spectrum,XRD,TEM and electron spectrum,which indicated that the powder with good characteristics of 70-100 nm can be obtained by sintering at 1 000℃.It was shown that the chemical composition of the sample was agreed with experimental requirements by electron spectrum analysis.

  12. Viscoelasticity of various gel films prepared from solvent-soluble constituents in coal; Sekitanchu no yobai kayoseibun kara sakuseishita shushu no gel maku no nendansei

    Energy Technology Data Exchange (ETDEWEB)

    Takanohashi, T.; Isoda, S.; Doi, S.; Iino, M. [Tohoku University, Sendai (Japan). Institute for Chemical Reaction Science

    1996-10-28

    Viscoelasticity of gel films prepared from solvent-soluble constituents without ash of coal using the mixed solvent of carbon disulfide and N-methyl-2-pyrrolidinone (CS2-NMP) was measured to study the network structure of the constituents. In experiment, Upper Freeport coal and Zao Zhuang coal were used as specimens. Viscoelasticity of various gels with different weight fractions of solvent was measured by creep measurement under a fixed load and stress-strain analysis under variable loads. In the 2nd and 3rd creep measurements, although no large changes in elastic strain and viscoelastic strain were found, viscous strain gradually decreased with an increase in viscosity. In the case of small weight fraction of solvent, small viscous strain and viscoelastic strain were found, while slightly large elastic strain was found. It was thus suggested that this elastic strain is derived from not only physical cross-linked networks by coal-solvent interaction but also those by coal-coal interaction in polymer chains of coal itself. 9 refs., 4 figs., 1 tab.

  13. Preparation, characterization and efficacy of lysostaphin-chitosan gel against Staphylococcus aureus.

    Science.gov (United States)

    Nithya, Sai; Nimal, T R; Baranwal, Gaurav; Suresh, Maneesha K; C P, Anju; Anil Kumar, V; Gopi Mohan, C; Jayakumar, R; Biswas, Raja

    2018-04-15

    Lysostaphin (LST) is a bacteriocin that cleaves within the pentaglycine cross bridge of Staphylococcus aureus peptidoglycan. Previous studies have reported the high efficiency of LST even against multi drug resistant S. aureus including methicillin resistant S. aureus (MRSA). In this study, we have developed a new chitosan based hydrogel formulation of LST to exploit its anti-staphylococcal activity. The atomic interactions of LST with chitosan were studied by molecular docking studies. The rheology and the antibacterial properties of the developed LSTC gel were evaluated. The developed LST containing chitosan hydrogel (LSTC gel) was flexible, flows smoothly and remains stable at physiological temperature. The in vitro studies by agar well diffusion and ex vivo studies in porcine skin model exhibited a reduction in S. aureus survival by ∼3 Log 10 CFU/mL in the presence of LSTC gel. The cytocompatibility of the gel was tested in vitro using macrophage RAW 264.7 cell line and in vivo in Drosophila melanogaster. A gradual disruption of S. aureus biofilms with the increase of LST concentrations in the LSTC gel was observed which was confirmed by SEM analysis. We conclude that LSTC gel could be highly effectual and advantageous over antibiotics in treating staphylococcal-topical and biofilm infections. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Preparation and evaluation of bioadhesive benzocaine gels for enhanced local anesthetic effects.

    Science.gov (United States)

    Shin, Sang-Chul; Lee, Jin-Woo; Yang, Kyu-Ho; Lee, Chi H

    2003-07-09

    This study was performed to develop new enhanced anesthetic benzocaine gels with a suitable bioadhesive property for local anesthetic effects. As the concentration of benzocaine in the HPMC gels increased up to 15%, the permeation of drug increased, thereafter slightly increased. The activation energy of drug permeation was 11.29 kcal/mol. Bioadhesive forces were also measured. The permeation rate of drug through the skin was studied using various enhancers, such as glycols, non-ionic surfactants or fatty acids. Among the enhancers used, diethylene glycol showed the most enhancing effects. Analgesic activity was examined using a tail-flick analgesimeter. According to the rat tail-flick test, the value of AUEC (0 - 360min) of 15% benzocaine gels containing diethylene glycol was 4662 +/- 200 s min, while that of gels without diethylene glycol was 3353 +/- 132 s min, showing about 1.39-fold increase in analgesic activity. Fifteen percentage of benzocaine gels containing diethylene glycol showed the most enhanced, prolonged analgesic effects, showing the maximum anesthetic effects at 240 min, while the gels without diethylene glycol showed maximum effect at 180 min.

  15. Preparation of Dispersion-Hardened Copper by Internal Oxidation

    DEFF Research Database (Denmark)

    Brøndsted, Povl; Sørensen, Ole Toft

    1978-01-01

    Internal oxidation experiments in CO2/CO atmospheres on Cu-Al alloys for preparation of dispersion-hardened Cu are described. The oxygen pressures of the atmospheres used in the experiments were controlled with a solid electrolyte oxygen cell based on ZrO2 (CaO). The particle size distributions o...

  16. Cross-linking by protein oxidation in the rapidly setting gel-based glues of slugs

    Science.gov (United States)

    Bradshaw, Andrew; Salt, Michael; Bell, Ashley; Zeitler, Matt; Litra, Noelle; Smith, Andrew M.

    2011-01-01

    SUMMARY The terrestrial slug Arion subfuscus secretes a glue that is a dilute gel with remarkable adhesive and cohesive strength. The function of this glue depends on metals, raising the possibility that metal-catalyzed oxidation plays a role. The extent and time course of protein oxidation was measured by immunoblotting to detect the resulting carbonyl groups. Several proteins, particularly one with a relative molecular mass (Mr) of 165×103, were heavily oxidized. Of the proteins known to distinguish the glue from non-adhesive mucus, only specific size variants were oxidized. The oxidation appears to occur within the first few seconds of secretion. Although carbonyls were detected by 2,4-dinitrophenylhydrazine (DNPH) in denatured proteins, they were not easily detected in the native state. The presence of reversible cross-links derived from carbonyls was tested for by treatment with sodium borohydride, which would reduce uncross-linked carbonyls to alcohols, but stabilize imine bonds formed by carbonyls and thus lead to less soluble complexes. Consistent with imine bond formation, sodium borohydride led to a 20–35% decrease in the amount of soluble protein with a Mr of 40–165 (×103) without changing the carbonyl content per protein. In contrast, the nucleophile hydroxylamine, which would competitively disrupt imine bonds, increased protein solubility in the glue. Finally, the primary amine groups on a protein with a Mr of 15×103 were not accessible to acid anhydrides. The results suggest that cross-links between aldehydes and primary amines contribute to the cohesive strength of the glue. PMID:21525316

  17. Graphene oxide-enhanced sol-gel transition sensitivity and drug release performance of an amphiphilic copolymer-based nanocomposite

    Science.gov (United States)

    Hu, Huawen; Wang, Xiaowen; Lee, Ka I; Ma, Kaikai; Hu, Hong; Xin, John H.

    2016-01-01

    We report the fabrication of a highly sensitive amphiphilic copolymer-based nanocomposite incorporating with graphene oxide (GO), which exhibited a low-intensity UV light-triggered sol-gel transition. Non-cytotoxicity was observed for the composite gels after the GO incorporation. Of particular interest were the microchannels that were formed spontaneously within the GO-incorporated UV-gel, which expedited sustained drug release. Therefore, the present highly UV-sensitive, non-cytotoxic amphiphilic copolymer-based composites is expected to provide enhanced photothermal therapy and chemotherapy by means of GO’s unique photothermal properties, as well as through efficient passive targeting resulting from the sol-gel transition characteristic of the copolymer-based system with improved sensitivity, which thus promises the enhanced treatment of patients with cancer and other diseases. PMID:27539298

  18. Far from the equilibrium crystallization of oxide quantum dots in dried inorganic gels

    Science.gov (United States)

    Costille, B.; Dumoulin, M.; Ntsame Abagha, A. M.; Thune, E.; Guinebretière, R.

    2018-06-01

    We synthesized, through the sol-gel process, far from the equilibrium amorphous materials in which heterogeneous crystallization allowed the formation of oxide quantum dots. The isothermal evolutions of the mean size of the nanocrystals and the crystallinity of the materials were determined through x-ray diffraction experiments. The heterogeneous crystallization is characterized by a kinetic behavior that is far from that expected, according to the classical nucleation theory. We demonstrate that the evolution of the crystallinity is characterized by an Avrami exponent largely smaller than 1. Finally, nanocrystals exhibiting a size significantly below their Bohr radius are obtained and the number of these nanocrystals increases during isothermal treatment, whereas their mean size remains quasi-constant.

  19. Photocatalytic Activity in CH3CN Related to the Surface Properties of TiO2 Powders Prepared by Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    Marta Bettoni

    2009-01-01

    Full Text Available Some TiO2 powders, prepared from titanium(IVtetraisopropoxide by the sol-gel method and thermally treated between 100 and 1000∘C, have been characterized by X-ray powder diffraction and by nitrogen adsorption and desorption at 77 K to calculate the BET-specific surface area, from which the micropore volume and the external surface area can be derived. The photocatalytic activity (ka of the above powders has been evaluated considering the TiO2-sensitized photo-oxidation of 4-methoxybenzyl alcohol in CH3CN as the test reaction. The decrease of ka have been related to the decrease of the BET surface area, the micropore volume, and the external surface area of the TiO2 powders, but a satisfactory linear correlation is observed only for the last superficial parameter.

  20. Preparation and nonlinear optical properties of indium nanocrystals in sodium borosilicate glass by the sol–gel route

    International Nuclear Information System (INIS)

    Zhong, Jiasong; Xiang, Weidong; Zhao, Haijun; Chen, Zhaoping; Liang, Xiaojuan; Zhao, Wenguang; Chen, Guoxin

    2012-01-01

    Graphical abstract: The sodium borosilicate glass doped with indium nanocrystals have been successfully prepared by sol–gel methods. And the indium nanocrystals in tetragonal crystal system have formed uniformly in the glass, and the average diameter of indium nanocrystals is about 30 nm. The third-order optical nonlinear refractive index γ, absorption coefficient β, and susceptibility χ (3) of the glass are determined to be −4.77 × 10 −16 m 2 /W, 2.67 × 10 −9 m/W, and 2.81 × 10 −10 esu, respectively. Highlights: ► Indium nanocrystals embedded in glass matrix have been prepared by sol–gel route. ► The crystal structure and composition are investigated by XRD and XPS. ► Size and distribution of indium nanocrystals is determined by TEM. ► The third-order optical nonlinearity is investigated by using Z-scan technique. -- Abstract: The sodium borosilicate glass doped with indium nanocrystals have been successfully prepared by sol–gel route. The thermal stability behavior of the stiff gel is investigated by thermogravimetric (TG) and differential thermal (DTA) analysis. The crystal structure of the glass is characterized by X-ray powder diffraction (XRD). Particle composition is determined by X-ray photoelectron spectroscopy (XPS). Size and distribution of the nanocrystals are characterized by transmission electron microscopy (TEM) as well as high-resolution transmission electron microscopy (HRTEM). Results show that the indium nanocrystals in tetragonal crystal structure have formed in glass, and the average diameter is about 30 nm. Further, the glass is measured by Z-scan technique to investigate the nonlinear optical (NLO) properties. The third-order NLO coefficient χ (3) of the glass is determined to be 2.81 × 10 −10 esu. The glass with large third-order NLO coefficient is promising materials for applications in optical devices.

  1. Sol-gel derived zinc oxide films alloyed with cobalt and aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Mamta [Department of Electronic Science, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021 (India); Mehra, R.M., E-mail: rammehra2003@yahoo.co [Department of Electronic Science, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021 (India)

    2010-05-03

    ZnO films codoped with 5 at.% Co and 1 at.% Al were prepared by sol-gel technique on corning glass and silicon substrates with precursor sols of different pH values. The pH was varied from 5.4 to 11 by adding varying amounts of monoethanolamine to the sol. Since pH plays an important role in controlling the properties of films, we discuss in detail the effect of pH value on the structural, morphological and optical properties of the grown films. X-ray diffraction and atomic force microscopy images reveal that the size of crystallites increases with pH of the sol. The variation of pH in the reaction system influences the density of homogeneous nucleation and the crystal growth along the c-axis. High quality Co and Al codoped ZnO films annealed at 600 {sup o}C have been obtained using a sol with pH = 9. These sol-gel derived films find their suitability to be used as dilute magnetic semiconductors.

  2. Sol-gel derived zinc oxide films alloyed with cobalt and aluminium

    International Nuclear Information System (INIS)

    Sharma, Mamta; Mehra, R.M.

    2010-01-01

    ZnO films codoped with 5 at.% Co and 1 at.% Al were prepared by sol-gel technique on corning glass and silicon substrates with precursor sols of different pH values. The pH was varied from 5.4 to 11 by adding varying amounts of monoethanolamine to the sol. Since pH plays an important role in controlling the properties of films, we discuss in detail the effect of pH value on the structural, morphological and optical properties of the grown films. X-ray diffraction and atomic force microscopy images reveal that the size of crystallites increases with pH of the sol. The variation of pH in the reaction system influences the density of homogeneous nucleation and the crystal growth along the c-axis. High quality Co and Al codoped ZnO films annealed at 600 o C have been obtained using a sol with pH = 9. These sol-gel derived films find their suitability to be used as dilute magnetic semiconductors.

  3. Preparation of sol-gel TiO2/purified Na-bentonite composites and their photovoltaic application for natural dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Saelim, Ni-on; Magaraphan, Rathanawan; Sreethawong, Thammanoon

    2011-01-01

    Highlights: → Natural dye from red cabbage was successfully employed in DSSC. → A fast sol-gel method to produce TiO 2 /clay thin film was proposed. → The sol-gel-prepared TiO 2 /clay was applied as the scattering layer on top of TiO 2 electrode. → Thicker sol-gel-prepared TiO 2 /clay electrode showed higher DSSC efficiency. - Abstract: The sol-gel TiO 2 /purified natural clay electrodes having Ti:Si molar ratios of 95:5 and 90:10 were initially prepared, sensitized with natural red cabbage dye, and compared to the sol-gel TiO 2 electrode in terms of physicochemical characteristics and solar cell efficiency. The results showed that the increase in purified Na-bentonite content greatly increased the specific surface area and total pore volume of the prepared sol-gel TiO 2 /purified Na-bentonite composites because the clay platelets prevented TiO 2 particle agglomeration. The sol-gel TiO 2 /5 mol% Si purified Na-bentonite and sol-gel TiO 2 /10 mol% Si purified Na-bentonite composites could increase the film thickness of solar cells without cracking when they were coated as a scattering layer on the TiO 2 semiconductor-based film, leading to increasing the efficiency of the natural dye-sensitized solar cells in this work.

  4. Preparation of (Bi,Pb)2Sr2Ca2Cu3Ox precursor powders by a modified polyethylene glycol based sol-gel process

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Andersen, N.H.

    2002-01-01

    A modified sol-gel process based on polyethylene glycol has been developed for preparing (Bi,Pb)(2)Sr2Ca2Cu3Ox precursor powders in view of Ag-sheeted tape manufacture. A careful control of the pH and concentration temperature yields an amorphous gel, which can be converted to a fine and extremely...

  5. Preparation and Evaluation of Novel In Situ Gels Containing Acyclovir for the Treatment of Oral Herpes Simplex Virus Infections

    Directory of Open Access Journals (Sweden)

    Binu Chaudhary

    2014-01-01

    Full Text Available The objective of this work was to develop an oral mucosal drug delivery system to facilitate the local and systemic delivery of acyclovir for the treatment of oral herpes infection caused by the herpes simplex virus (HSV. An in situ gelling system was used to increase the residence time and thus the bioavailability of acyclovir in oral mucosa. Temperature and pH trigged in situ gel formulations were prepared by cold method using polymers like poloxamer 407, carbopol 934, and HPMC. Glycerin and a mixture of tween 80 and ethanol (1 : 2 ratio were used as the drug dissolving solvent. The pH of carbopol containing formulation was adjusted to pH 5.8 while the pH of poloxamer solution was adjusted to pH 7. These formulations were evaluated for sol-gel transition temperature, gelling capacity, pH, viscosity, spreadability, gel strength, drug content, ex-vitro permeation, and mucoadhesion. The gelation temperatures of all the formulations were within the range of 28–38°C. All the formulations exhibited fairly uniform drug content (98.15–99.75%. Drug release study of all the formulations showed sustained release properties. The release of drug through these in situ gel formulations followed the Higuchi model and Korsmeyer peppas model mechanism.

  6. Influence of silane on the structure of polystyrene prepared by sol-gel coatings via UV curing

    Directory of Open Access Journals (Sweden)

    Balbay Senay

    2017-01-01

    Full Text Available Light, heat, oxygen, moisture, ozone, atmospheric pollution and biological effects are the most important effectives wreak to chemical degradation in the polymer structure. In result of chemical degradation on the polymer consist of problems such as discoloration, brittleness, surface cracks, perspiration, crumbling, smell, surface acidity. In this work, it is aimed to improve the problem of the polystyrene (PS material against chemical degradation. For this reason, PS is coated with silica sol-gel hybrid coating. Silica sol-gel was synthesized by using vinyltrimethoxysilane (VTMS as a cross-linker and tetraethylorthosilicate (TEOS as a silica source. Firstly, four different pre-treatment technique (oven, vacuum oven, lyophilizer and freezing was studied to determine the most suitable pre-treatment technique for coating on PS substrate of sol-gel prepared with initial formulation (S1. A freezing technique gave the best results for coating sample. The change of surface colour of coated PS was measured by CIE L*a*b* methods. Secondly, the most suitable curing agent (Irgacure 184, Irgacure 819, Darocur 1173 and TiO2 as crystalline anatase phase was determined to coat the sol-gel on PS. It was determined to the lowest yellowing of PS surface hybrid coated as UV curing of TEOS sol modified by VTMS and TiO2 as photo-initiators. Finally, the chemical and morphological structure of the coated PS samples was determined by FT-IR and SEM instruments, respectively.

  7. Sol-Gel Deposition of Iridium Oxide for Biomedical Micro-Devices

    Directory of Open Access Journals (Sweden)

    Cuong M. Nguyen

    2015-02-01

    Full Text Available Flexible iridium oxide (IrOx-based micro-electrodes were fabricated on flexible polyimide substrates using a sol-gel deposition process for utilization as integrated pseudo-reference electrodes for bio-electrochemical sensing applications. The fabrication method yields reliable miniature on-probe IrOx electrodes with long lifetime, high stability and repeatability. Such sensors can be used for long-term measurements. Various dimensions of sol-gel iridium oxide electrodes including 1 mm × 1 mm, 500 µm × 500 µm, and 100 µm × 100 µm were fabricated. Sensor longevity and pH dependence were investigated by immersing the electrodes in hydrochloric acid, fetal bovine serum (FBS, and sodium hydroxide solutions for 30 days. Less pH dependent responses, compared to IrOx electrodes fabricated by electrochemical deposition processes, were measured at 58.8 ± 0.4 mV/pH, 53.8 ± 1.3 mV/pH and 48 ± 0.6 mV/pH, respectively. The on-probe IrOx pseudo-reference electrodes were utilized for dopamine sensing. The baseline responses of the sensors were higher than the one using an external Ag/AgCl reference electrode. Using IrOx reference electrodes integrated on the same probe with working electrodes eliminated the use of cytotoxic Ag/AgCl reference electrode without loss in sensitivity. This enables employing such sensors in long-term recording of concentrations of neurotransmitters in central nervous systems of animals and humans.

  8. Sol-Gel Deposition of Iridium Oxide for Biomedical Micro-Devices

    Science.gov (United States)

    Nguyen, Cuong M.; Rao, Smitha; Yang, Xuesong; Dubey, Souvik; Mays, Jeffrey; Cao, Hung; Chiao, Jung-Chih

    2015-01-01

    Flexible iridium oxide (IrOx)-based micro-electrodes were fabricated on flexible polyimide substrates using a sol-gel deposition process for utilization as integrated pseudo-reference electrodes for bio-electrochemical sensing applications. The fabrication method yields reliable miniature on-probe IrOx electrodes with long lifetime, high stability and repeatability. Such sensors can be used for long-term measurements. Various dimensions of sol-gel iridium oxide electrodes including 1 mm × 1 mm, 500 μm × 500 μm, and 100 μm × 100 μm were fabricated. Sensor longevity and pH dependence were investigated by immersing the electrodes in hydrochloric acid, fetal bovine serum (FBS), and sodium hydroxide solutions for 30 days. Less pH dependent responses, compared to IrOx electrodes fabricated by electrochemical deposition processes, were measured at 58.8 ± 0.4 mV/pH, 53.8 ± 1.3 mV/pH and 48 ± 0.6 mV/pH, respectively. The on-probe IrOx pseudo-reference electrodes were utilized for dopamine sensing. The baseline responses of the sensors were higher than the one using an external Ag/AgCl reference electrode. Using IrOx reference electrodes integrated on the same probe with working electrodes eliminated the use of cytotoxic Ag/AgCl reference electrode without loss in sensitivity. This enables employing such sensors in long-term recording of concentrations of neurotransmitters in central nervous systems of animals and humans. PMID:25686309

  9. Preparation and characterization of several transition metal oxides

    International Nuclear Information System (INIS)

    Wold, A.; Dwight, K.

    1989-01-01

    The structure-property relationships of several conducting transition metal oxides, as well as their preparative methods, are presented in this paper. The importance of preparing homogeneous phases with precisely known stoichiometry is emphasized. A comparison is also made of the various techniques used to prepare both polycrystalline and single crystal samples. For transition metal oxides, the metallic properties are discussed either in terms of metal-metal distances which are short enough to result in metallic behavior, or in terms of the formation of a π* conduction band resulting from covalent metal-oxygen interactions. Metallic behavior is observed when the conduction bands are populated with either electrons or holes. The concentration of these carriers can be affected by either cation or anion substitutions. The discussion in this presentation will be limited to the elements Re, Ti, V, Cr, Mo, and Cu

  10. Study of the performance of gels of molybdenum containing several cations for the preparation of 99Mo and 99mTc

    International Nuclear Information System (INIS)

    Moraes, Vanessa

    2005-01-01

    99m Tc is the most employed radioisotope in Nuclear Medicine, due to its nuclear characteristics: short half-life (6.04 h); emission of low energy gamma ray (140 keV); no emission of β - ; generated by the radioactive decay of 99 Mo (radioisotope generator system). 99 Mo can be produced in cyclotron or nuclear reactor by the irradiation of 235 U (n, f) 99 Mo or by the 98 Mo (n, γ) 90 Mo reaction. Four different kinds of generators of 99m Tc can be employed, based on the separation techniques: column chromatographic using alumina, with fission 99 Mo; solvent extraction using methylethylketone; sublimation of technetium heptoxide; gel type chromatographic generator, that contains molybdenum. IPEN, aiming the nationalization of the 99m Tc generators production, developed a gel type generator that uses zirconium molybdate. Three types of gels are studied in the work: molybdenum gel with titanium, molybdenum gel with cerium and molybdenum gel with hafnium, that were compared with the molybdenum gel with zirconium. The variables studied in the gel preparation are: mass relation between Mo and the cation, NaOH concentration, temperature and final pH of the product. After the preparation, the gels are analysed in relation to the amount of Mo and the cation, structure and gel particle size. The gel is irradiated and later a generator system is prepared, and the elutions are analysed in order to measure the 99m Tc elution efficiency. The results showed that the molybdenum gel with titanium had the best performance in all analysis. (author)

  11. Luminescent Eosin Y–SiO{sub 2} hybrid nano and microrods prepared by sol–gel template method

    Energy Technology Data Exchange (ETDEWEB)

    Secu, M., E-mail: msecu@infim.ro [National Institute for Materials Physics, P.O. Box MG-7, Bucharest–Magurele, 077125 (Romania); Secu, C.E.; Sima, M.; Negrea, R.F.; Bartha, C. [National Institute for Materials Physics, P.O. Box MG-7, Bucharest–Magurele, 077125 (Romania); Dinescu, M.; Damian, V. [National Institute for Laser, Plasma and Radiation, P.O. Box MG-36, Bucharest–Magurele 077125 (Romania)

    2013-11-15

    Sol–gel chemistry within the pores of a polycarbonate template membrane was used for the preparation of Eosin Y–SiO{sub 2} hybrid nano- and microrods, using tetraethylorthosilicate [TEOS, Si(OC{sub 2}H{sub 5}){sub 4}] as the precursor in the presence of trifluoroacetic acid (TFA) catalyst. The ethanolic solution of Eosin-Y was added to the silica sol to trap dye molecules inside the SiO{sub 2} gel network during the gelation. Structural and morphological characterization using scanning electron microscopy (SEM) and luminescence microscopy have shown the formation of rods with 200 nm and 1.2 μm diameter and about 30 μm length, exhibiting luminescence properties. Spectroscopic characterization has shown that the luminescence is due to Eosin-Y molecule in the xerogel porous network, surrounded by a solvation shell given mainly by the water. -- Highlights: • Sol–gel template method was used to prepare Eosin Y–SiO{sub 2} hybrid rods-type structures. • Morphological characterization has shown nano- and microrods with luminescent properties. • Luminescence is due to Eosin-Y molecule surrounded by a solvation shell given by water.

  12. Luminescent Eosin Y–SiO2 hybrid nano and microrods prepared by sol–gel template method

    International Nuclear Information System (INIS)

    Secu, M.; Secu, C.E.; Sima, M.; Negrea, R.F.; Bartha, C.; Dinescu, M.; Damian, V.

    2013-01-01

    Sol–gel chemistry within the pores of a polycarbonate template membrane was used for the preparation of Eosin Y–SiO 2 hybrid nano- and microrods, using tetraethylorthosilicate [TEOS, Si(OC 2 H 5 ) 4 ] as the precursor in the presence of trifluoroacetic acid (TFA) catalyst. The ethanolic solution of Eosin-Y was added to the silica sol to trap dye molecules inside the SiO 2 gel network during the gelation. Structural and morphological characterization using scanning electron microscopy (SEM) and luminescence microscopy have shown the formation of rods with 200 nm and 1.2 μm diameter and about 30 μm length, exhibiting luminescence properties. Spectroscopic characterization has shown that the luminescence is due to Eosin-Y molecule in the xerogel porous network, surrounded by a solvation shell given mainly by the water. -- Highlights: • Sol–gel template method was used to prepare Eosin Y–SiO 2 hybrid rods-type structures. • Morphological characterization has shown nano- and microrods with luminescent properties. • Luminescence is due to Eosin-Y molecule surrounded by a solvation shell given by water

  13. Highly Conducting Nanosized Monodispersed Antimony-Doped Tin Oxide Particles Synthesized via Nonaqueous Sol−Gel Procedure

    Czech Academy of Sciences Publication Activity Database

    Müller, V.; Rasp, M.; Štefanić, G.; Ba, J.; Günther, S.; Rathouský, Jiří; Niederberger, M.; Fattakhova Rohlfing, D.

    2009-01-01

    Roč. 21, č. 21 (2009), s. 5229-5236 ISSN 0897-4756 Institutional research plan: CEZ:AV0Z40400503 Keywords : nanoparticles * nonaqueous Ssl -gel procedure * oxide materials Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.368, year: 2009

  14. Special Advanced Studies for Pollution Prevention. Delivery Order 0017: Sol-Gel Surface Preparation for Carbon Steel and Stainless Steel Bonding

    National Research Council Canada - National Science Library

    Zheng, Haixing

    1997-01-01

    The objective of this program is to study the feasibility of using sol-gel active alumina coatings for the surface preparation of carbon steel and stainless steel for adhesive bonding, and to optimize...

  15. Gel spinning of PVA composite fibers with high content of multi-walled carbon nanotubes and graphene oxide hybrids

    International Nuclear Information System (INIS)

    Wei, Yizhe; Lai, Dengpan; Zou, Liming; Ling, Xinlong; Lu, Hongwei; Xu, Yongjing

    2015-01-01

    In this report, poly (vinyl alcohol) (PVA) composite fibers with high content of multi-walled carbon nanotubes and graphene oxide (MWCNTs-GO) hybrids were prepared by gel spinning, and were characterized by TGA, DSC, SEM, XL-2 yarn strength tester and electrical conductivity measurement. The total content of MWCNTs-GO hybrids in the PVA composite fibers, which is up to 25 wt%, was confirmed by TGA analysis. The DSC measurement shows that the melting and crystallization peaks decreased after the addition of nano-fillers. This is due to the reason that the motion of PVA chains is completely confined by strong hydrogen bonding interaction between PVA and nano-fillers. After the addtion of GO, the dispersibility of MWCNTs in composite fibers improved slightly. And the tensile strength and Young's modulus increased by 38% and 67%, respectively. This is caused by the increased hydrogen bonding interaction and synergistic effect through hybridization of MWCNTs and GO. More significantly, the electrical conductivity of PVA/MWCNTs/GO composite fibers enhanced by three orders of magnitude with the addition of GO. (paper)

  16. Influence of annealing temperature on microstructure and optical properties of sol-gel derived tungsten oxide films

    International Nuclear Information System (INIS)

    Sun Xilian; Cao Hongtao; Liu Zhimin; Li Jianzhong

    2009-01-01

    Tungsten oxide (WO 3 ) thin films have been extensively studied for their interesting physical properties and a variety of potential applications in electrochromic devices. In order to explore the possibility of using these in electrochromic devices, a preliminary and thorough study of the optical properties of the host materials is an important step. Based on this, the influence of annealing temperature on the structural, surface morphological, optical and electrochromic properties has been investigated in the present work. The host material, WO 3 films, has been prepared from an ethanolic acetylated peroxotungstic acid sol containing 5 wt.% oxalic acid dehydrate (OAD) by sol-gel technique. The monoclinic structure and textured nature change of the films with the temperature increasing have been investigated by X-ray diffraction analysis. The surface morphology evolution of the films has been characterized by SEM. The shift in absorption edge towards the higher wavelength region observed from optical studies may be due to the electron scattering effects and the optical band filling effect that reveals the crystallization of the film. The amorphous film shows better optical modulation (ΔT = 76.9% at λ = 610 nm), fast color-bleach kinetics (t c ∼ 4 s and t b ∼ 9 s) and good reversibility (Q b /Q c = 90%), thereby rendering it suitable for smart window applications.

  17. Investigation of the visible light photocatalytic activity of BiVO4 prepared by sol gel method assisted by ultrasonication.

    Science.gov (United States)

    Deebasree, J P; Maheskumar, V; Vidhya, B

    2018-07-01

    Visible light induced photocatalyst BiVO 4 with monoclinic scheelite structure has been synthesised via sol gel method assisted by ultrasonication. The prepared samples were characterised using X-ray diffraction (XRD), scanning electron microscope (SEM), UV-Vis diffused reflectance spectroscopy (DRS) techniques. The photocatalytic efficiency was evaluated by decolourisation of MB under visible light irradiation. The effect of ultrasound output power on the properties of BiVO 4 during and after preparation by sol-gel method has been compared with normal agitated sample (As prepared). The power of ultrasonic vibration has been varied and an ideal output power which yields better catalytic efficiency is determined. BiVO 4 sonicated with 80 W during preparation 80 W (D) exhibited relatively high surface area, better surface morphology and better catalytic efficiency compared to other samples which were sonicated with 100, 160 and 200 W. The results signify that the photodegradation rate of BiVO 4 80 W (D) sample is high up to 96% in 90 min compared to other samples. Change in morphology leading to better catalytic efficiency was obtained just by exposing the sample to ultrasonic radiation without addition of any surfactant. The recovery test showed that the sample was stable for four consecutive cycles. Using radical test, a reasonable mechanism for photodegradation has been proposed. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Preparation of Raspberry-like Superhydrophobic SiO2 Particles by Sol-gel Method and Its Potential Applications

    Directory of Open Access Journals (Sweden)

    Xu Gui-Long

    2011-12-01

    Full Text Available Raspberry‐like SiO2 particles with a nano‐micro‐binary structure were prepared by a simple sol‐gel method using tetraethoxysilane (TEOS and methyltriethoxysilane (MTES as precursors. The chemical components and morphology of the SiO2 particles were characterized by Fourier transform infrared spectroscopy (FT‐IR and a Transmission electron microscope (TEM. The surface topography and wetting behaviour of the raspberry‐like SiO2 surface were observed with a Scanning electron microscope (SEM and studied by the water/oil contact angle (CA, respectively. The thermal stability of the prepared SiO2 particles was characterized by TGA analysis. The results show that the highly dispersed SiO2 particles initially prepared by the sol‐gel method turn into raspberry‐like particles with during the aging process. The raspberry‐like SiO2 particles show superhydrophobicity and superoleophilicity across a wide range of pH values. The SiO2 particles were thermally stable up to 475°C, while above this temperature the hydrophobicity decreases and finally becomes superhydrophobic when the temperature reaches 600°C. The raspberry‐like SiO2 particles which were prepared have potential applications in the fields of superhydrophobic surfaces, water‐oil separation, anti‐corrosion and fluid transportation.

  19. An economic route to mass production of graphene oxide solution for preparing graphene oxide papers

    Energy Technology Data Exchange (ETDEWEB)

    Liou, Yan-Jia; Tsai, Bo-Da; Huang, Wu-Jang, E-mail: wjhuang@mail.npust.edu.tw

    2015-03-15

    Highlights: • Graphene oxide paper can be prepared from synthesized graphene sheet containing carbon materials. • Graphene oxide paper can be used as a phase change materials for thermal storage. • To prepare graphene oxide paper from synthesized graphene sheet containing carbon materials could highly reduce the cost. - Abstract: Graphene oxide paper (GOP) is a composite material fabricated from graphene oxide (GO) solution. In addition, it can be a novel and potential material for application on the separation of water vapor from gaseous steam or larger alkali ions from aqueous solution. GOP could be used as electricity and thermal storage materials. The preparation of GO commonly uses high purity natural or artificial graphite. It is difficult to prepare GOP from artificial graphite powder due to the cost of $1,450 US/ton. In this study, we tried to prepare GOPs from homemade graphene sheets containing carbon materials (GSCCMs) and evaluate the thermal properties of GSCCM derived GOPs. Results show that GSCCM derived GOPs have a higher phase transition temperature, and the average mesophase phase change enthalpy is 9.41 J/g, which is 2.87 times higher than graphite derived GOP. Therefore, to prepare GOP from GSCCMs could highly reduce the cost.

  20. Comparative facile methods for preparing graphene oxide-hydroxyapatite for bone tissue engineering.

    Science.gov (United States)

    Raucci, M G; Giugliano, D; Longo, A; Zeppetelli, S; Carotenuto, G; Ambrosio, L

    2017-08-01

    Motivated by the success of using graphene oxide (GO) as a nanofiller of composites, there is a drive to search for this new kind of carbon material as a bioactive component in ceramic materials. In the present study, biomineralized GO was prepared by two different approaches, represented by in situ sol-gel synthesis and biomimetic treatment. It was found that in the biocomposites obtained by the sol-gel approach, the spindle-like hydroxyapatite nanoparticles, with a diameter of ca. 5 ± 0.37 nm and a length of ca. 70 ± 2.5 nm, were presented randomly and strongly on the surface. The oxygen-containing functional groups, such as hydroxyl and carbonyl, present on the basal plane and edges of the GO sheets, play an important role in anchoring calcium ions, as demonstrated by FT-IR and TEM investigations. A different result was obtained for biocomposites after biomimetic treatment: an amorphous calcium phosphate on GO sheet was observed after 5 days of treatment. These different approaches resulted in a diverse effect on the proliferation and differentiation of osteogenic mesenchymal stem cells. In fact, in biocomposites prepared by the sol-gel approach the expression of an early marker of osteogenic differentiation, ALP, increases with the amount of GO in the first days of cell culture. Meanwhile, biomimetic materials sustain cell viability and proliferation, even if the expression of alkaline phosphatase activity in a basal medium is delayed. These findings may provide new prospects for utilizing GO-based hydroxyapatite biocomposites in bone repair, bone augmentation and coating of biomedical implants and broaden the application of GO sheets in biological areas. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  1. Specially Treated Aramid Fiber Stabilized Gel-Emulsions: Preparation of Porous Polymeric Monoliths and Highly Efficient Removing of Airborne HCHO.

    Science.gov (United States)

    Liu, Jianfei; Chen, Xiangli; Wang, Pei; Fu, Xuwei; Liu, Kaiqiang; Fang, Yu

    2017-08-01

    Porous polymeric monoliths with densities as low as ≈0.060 g cm -3 are prepared in a gel-emulsion template way, of which the stabilizer employed is a newly discovered acidified aramid fiber that is so efficient that 0.05% (w/v, accounts for continuous phase) is enough to gel the system. The porous monoliths as obtained can be dried at ambient conditions, avoiding energy-consuming processes. Importantly, the monoliths show selective adsorption to HCHO, and the corresponding adsorption capacity (M6) is ≈2700 mg g -1 , the best result that is reported until now. More importantly, the monoliths can be reused after drying. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Mechanical and thermal expansion properties of β-eucryptite prepared by sol-gel methods and hot pressing

    International Nuclear Information System (INIS)

    Xia, L.; Wen, G.W.; Qin, C.L.; Wang, X.Y.; Song, L.

    2011-01-01

    Research highlights: → Dense LAS glass-ceramics were fabricated by sol-gel and hot pressing technique. → The LAS glass-ceramics have relative good mechanical properties. → The negative thermal expansion behavior of LAS glass-ceramics was investigated. -- Abstract: The microstructures, mechanical properties and thermal expansion behavior of monolithic lithium aluminosilicate glass-ceramics, prepared by sol-gel method and hot pressing, were investigated by using X-ray diffraction, scanning and transmission electron microscopies, three-point bend tests and dilatometry. β-eucryptite appeared as main phase in the monolithic lithium aluminosilicate glass-ceramics. The glass ceramics exhibited high relative densities and the average flexural strength and fracture toughness values were 154 MPa and 2.46 MPa m 1/2 , respectively. The lithium aluminosilicate glass-ceramics hot pressed 1300 and 1350 o C demonstrated negative coefficient of thermal expansion, which was affected by amount and type of crystalline phases.

  3. The development of latent fingerprints by zinc oxide and tin oxide nanoparticles prepared by precipitation technique

    Science.gov (United States)

    Luthra, Deepali; Kumar, Sacheen

    2018-05-01

    Fingerprints are the very important evidence at the crime scene which must be developed clearly with shortest duration of time to solve the case. Metal oxide nanoparticles could be the mean to develop the latent fingerprints. Zinc oxide and Tin Oxide Nanoparticles were prepared by using chemical precipitation technique which were dried and characterized by X-ray diffraction, UV-Visible spectroscopy and FTIR. The size of zinc oxide crystallite was found to be 14.75 nm with minimum reflectance at 360 nm whereas tin oxide have the size of 90 nm and reflectance at minimum level 321 nm. By using these powdered samples on glass, plastic and glossy cardboard, latent fingerprints were developed. Zinc oxide was found to be better candidate than tin oxide for the fingerprint development on all the three types of substrates.

  4. On shear rheology of gel propellants

    Energy Technology Data Exchange (ETDEWEB)

    Rahimi, Shai; Peretz, Arie [RAFAEL, MANOR Propulsion and Explosive Systems Division, Haifa (Israel); Natan, Benveniste [Faculty of Aerospace Engineering, Technion - Israel Institute of Technology, Haifa (Israel)

    2007-04-15

    Selected fuel, oxidizer and simulant gels were prepared and rheologically characterized using a rotational rheometer. For fuel gelation both organic and inorganic gellants were utilized, whereas oxidizers and simulants were gelled with addition of silica and polysaccharides, respectively. The generalized Herschel-Bulkley constitutive model was found to most adequately represent the gels studied. Hydrazine-based fuels, gelled with polysaccharides, were characterized as shear-thinning pseudoplastic fluids with low shear yield stress, whereas inhibited red-fuming nitric acid (IRFNA) and hydrogen peroxide oxidizers, gelled with silica, were characterized as yield thixotropic fluids with significant shear yield stress. Creep tests were conducted on two rheological types of gels with different gellant content and the results were fitted by Burgers-Kelvin viscoelastic constitutive model. The effect of temperature on the rheological properties of gel propellant simulants was also investigated. A general rheological classification of gel propellants and simulants is proposed. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  5. Afterglow luminescence in sol-gel/Pechini grown oxide materials: persistence or phosphorescence process? (Conference Presentation)

    Science.gov (United States)

    Sontakke, Atul; Ferrier, Alban; Viana, Bruno

    2017-03-01

    Persistent luminescence and phosphorescence, both yields afterglow luminescence, but are completely different mechanisms. Persistent luminescence involves a slow thermal release of trapped electrons stored in defect states, whereas the phosphorescence is caused due to triplet to singlet transition [1,2]. Many persistent luminescence phosphors are based on oxide inorganic hosts, and exhibit long afterglow luminescence after ceasing the excitation. We observed intense and long afterglow luminescence in sol-gel/pechini grown inorganic oxides, and as a first interpretation thought to be due to persistence mechanism. However, some of these materials do not exhibit defect trap centers, and a detailed investigation suggested it is due to phosphorescence, but not the persistence. Phosphorescence is not common in inorganic solids, and that too at room temperature, and therefore usually misinterpreted as persistence luminescence [3]. Here we present a detailed methodology to distinguish phosphorescence from persistence luminescence in inorganic solids, and the process to harvest highly efficient long phosphorescence afterglow at room temperature. 1. Jian Xu, Setsuhisa Tanabe, Atul D. Sontakke, Jumpei Ueda, Appl. Phys. Lett. 107, 081903 (2015) 2. Sebastian Reineke, Marc A. Baldo, Scientific Reports, 4, 3797 (2014) 3. Pengchong Xue, Panpan Wang, Peng Chen, Boqi Yao, Peng Gong, Jiabao Sun, Zhenqi Zhang, Ran Lu, Chem. Sci. (2016) DOI: 10.1039/C5SC03739E

  6. Fabrication and characterization of Zinc Oxide (ZnO) nanoparticle by sol-gel method

    International Nuclear Information System (INIS)

    Siswanto; Akwalia, Putri Riski; Rochman, Nurul T.

    2017-01-01

    Currently, nanomaterial is an interestingfield of study. This is due to its chemical and physical properties that are superior to that of large-sized materials. One nanomaterial widely studied is zinc oxide (ZnO). In this study, a synthesis of ZnO nanoparticles made by Sol-Gel method was conducted. The process parameters used are variations in pH, in increasing order, of 7; 8; 9; 10; 11; and 12. There are two principal reactions to produce a compound oxide, namely hydrolysis and condensation. NaOH is an agent for the hydrolysis of (CH 3 COO) 2 Zn resultingin Zn (OH) 2 . Subsequently, condensation produces ZnO. Calcination was carried out at a temperature of 80 ° C for 1 hour. The ccharacterization of the samples showed that the condition of pH 12 produced the best sample with a size of 73.8 nm and ZnO percentage of 100%. Although pH 7 produced a particle size of 1.3 nm, the percentage of ZnO formed was only 42.9%. The calcination process was performed to remove CH 3 COONa. However, the process can lead to aggregation of ZnO particles to each other, which increases the particle size. (paper)

  7. Preparation of a sinterable beryllium oxide through decomposition of beryllium hydroxide (1963)

    International Nuclear Information System (INIS)

    Bernier, M.

    1963-01-01

    In the course of the present study, we have attempted to precise the factors which among the ones effective in the course of the preparation of the beryllium hydroxide and oxide and during the sintering have an influence on the final result: the density and homogeneity of the sintered body. Of the several varieties of hydroxides precipitated from a sulfate solution the β-hydroxide only is always contaminated with beryllium sulfate and cannot be purified even by thorough washing. We noticed that those varieties of the hydroxide (gel, α, β) have different decomposition rates; this behaviour is used to identify and even to dose the different species in (α, β) mixtures. The various hydroxides transmit to the resulting oxides the shape they had when precipitated. Accordingly the history of the oxide is revealed by its behaviour during its fabrication and sintering. By comparing the results of the sintering operation with the various measurements performed on the oxide powders we are led to the conclusion that an oxide obtained from beryllium hydroxide is sinterable under vacuum if the following conditions are fulfilled: the particle size must lie between 0.1 and 0.2 μ and the BeSO 4 content of the powder must be less than 0.25 per cent wt (expressed as SO 3 /BeO). The best fitting is obtained with the oxide issued from an α-hydroxide precipitated as very small aggregates and with a low sulfur-content. We have observed that this is also the case for the oxide obtained by direct calcination of beryllium sulfate. (author) [fr

  8. [Treatment of postburn and postoperative cicatrices using karipaine cream preparations and karipaine ultra gel].

    Science.gov (United States)

    Zhernov, O A; Osadcha, O I; Zhernov, A O; Nazarenko, V M; Staskevych, S V

    2011-07-01

    Peculiarities of the burn wound course and the cicatricial tissue formation are shown. Clinical efficacy of application of cream Karipaine and gel Karipaine Ultra was proved, witnessed by improvement of the cell to tissue interaction as well as the connective tissue metabolism and the cicatricial tissue reconstruction.

  9. Preparation of nanocrystalline Mg4Nb2O9 by citrate gel method

    Indian Academy of Sciences (India)

    Unknown

    using potassium niobate precursor. The purpose ... ficult to maintain reaction conditions. This citrate ... of metal ions by poly functional carboxyl acids such as citric acid or ... on a water bath at 100°C a gel was formed after evaporation of water.

  10. Nanocrystalline Ni-Zn ferrites prepared by sol-gel method

    Czech Academy of Sciences Publication Activity Database

    Popovici, M.; Savii, C.; Nižňanský, Daniel; Šubrt, Jan; Boháček, Jaroslav; Becherescu, D.; Caizer, C.; Enache, C.; Ionescu, C.

    2003-01-01

    Roč. 5, č. 1 (2003), s. 251-256 ISSN 1454-4164 R&D Projects: GA MŠk LN00A028 Institutional research plan: CEZ:AV0Z4032918 Keywords : nanostructures * sol-gel processing * XRD Subject RIV: CA - Inorganic Chemistry Impact factor: 0.996, year: 2003

  11. Epoxy-based organic-inorganic nanocomposite coatings and films prepared by sol-gel process

    Czech Academy of Sciences Publication Activity Database

    Špírková, Milena; Brus, Jiří; Matějka, Libor

    2004-01-01

    Roč. 6, 3-4 (2004), s. 7-15 R&D Projects: GA ČR GA203/01/0735; GA AV ČR IAA4050008; GA AV ČR KSK4050111 Institutional research plan: CEZ:AV0Z4050913 Keywords : sol-gel process * nanocomposite s * solid-state NMR Subject RIV: CD - Macromolecular Chemistry

  12. Structure of mineral gels

    International Nuclear Information System (INIS)

    Miranda Salvado, I.M.; Margaca, F.M.A.; Teixeira, J.

    1999-01-01

    Small Angle Neutron Scattering (SANS) measurements have been performed to investigate the nanoscale structure of materials of the systems xTiO 2 -(1-x)SiO 2 and xZrO 2 -(1-x)SiO 2 with x ≤ 10 mol % at different processing stages. The materials were prepared by sol-gel using the alkoxides method, in strong acidic conditions. Samples were studied as xerogels heat-treated at 120 and 850 deg. C and as wet gels at gel point and after aging. All samples showed identical microstructure at gel point, extended linear chains ∼10 nm long. The aged gel has a mass fractal structure with fractal dimension of 1.7 - 1.9. The 120 deg. C heat-treated xerogels show homogeneous oxide regions with mass fractal structure. For the 850 deg. C heat-treated xerogel the oxide regions average size has reduced and it has densified as compared to 120 deg. C heat-treated sample. (author)

  13. Nonequilibrium phase formation in oxides prepared at low temperature: Fergusonite-related phases

    International Nuclear Information System (INIS)

    Mather, S.A.; Davies, P.K.

    1995-01-01

    Sol-gel methods have been developed to prepare YNbO 4 , YTaO 4 , and other rare-earth niobates and tantalates with fergusonite-related crystal structures. At low temperatures, all of the fergusonites, with the exception of SmTaO 4 , crystallize in a metastable tetragonal (T') structure similar to that of tetragonal zirconia. Although all of the equilibrium forms of these oxides adopt a crystal structure containing an ordered distribution of the trivalent and pentavalent cations, a random cation distribution is obtained in the metastable T' phase. Metastable phase formation is often ascribed solely to kinetically limited topotactic crystallization. However, the changes in the grain size and unit-cell volumes that accompany the metastable-to-equilibrium fergusonite conversions imply that other physical phenomena induced by small-particle synthesis, namely the Gibbs-Thompson pressure effect and the increased contribution of surface energy, cannot be ignored

  14. The Influence of Uranium Content and PVA/U Ratio on Physical Propertiesof PVA-U Gel and Its Oxide

    International Nuclear Information System (INIS)

    Damunir; W, Bangun; Indra-Suryawan; Endang-Nawangsih

    2000-01-01

    The influence of uranium content and PVA/U ratio on physical propertiesof PVA-U gel and its oxide has been investigated. Fifty milliliters of uranylnitrate solution containing 100 g U/l was neutralized using 1M NH 4 0H. Thesolution was converted into PVA-U sol by adding 9.18 % PVA while mixed andheated at 80 o C for 20 minutes. In order to find spherical gel, the solsolution was dropped into a 5 M NH 4 0H solution at room temperature. Theshape formed of the gels small spherical, shape of the formed gels werefiltered, washed and heated at 120 o C. After that the gels were calcined at800 o C for 4 hours. The formed U 3 O 8 particles. Under a similar method, theinfluence of uranium content from 150-400 g/l and the influence of PVA/Uratio of 6.5-12.5 % in 100 g U/l were studied. Characterization of the resultwas obtained from physical properties of the gel and its oxide in the form ofdensity using pycnometer, surface area using surface areameter with N 2 asabsorbent and particle size/ shape using a loop and optical microscope. Theexperimental results showed that both uranium content and PVA/U ratioaffected the physical properties of the kernel properties. The best resultoccurred at uranium content of 100 g/l and PVA/U 9.18 %. The resulted gelwith solid content of 89.17 %, density of 3.36 g/l and size of 124 μm. Theresulted oxide U 3 0 8 had density of 7.98 g U/l, surface area of specific of0.449 m 2 /g and grain size of 810 μm. (author)

  15. Microleakage and antibacterial properties of ZnO and ZnO:Ag nanopowders prepared via a sol-gel method for endodontic sealer application

    Energy Technology Data Exchange (ETDEWEB)

    Shayani Rad, M.; Kompany, A. [Ferdowsi University of Mashhad, Materials and Electroceramics Laboratory, Department of Physics, Faculty of Sciences (Iran, Islamic Republic of); Khorsand Zak, A., E-mail: alikhorsandzak@gmail.com [Esfarayen University, Nanotechnology Laboratory (Iran, Islamic Republic of); Javidi, M.; Mortazavi, S. M. [Mashhad University of Medical Sciences, Dental Material Research Centre, Department of Endodontics, Faculty of Dentistry (Iran, Islamic Republic of)

    2013-09-15

    One of the most important problems in dentistry is the microleakage, whether apical or coronal, which may cause failure of root canal therapy. The aim of this study is to prepare suitable sealer to decrease the microleakage of the root canals as well as having good antibacterial property. Pure ZnO and ZnO:Ag nanopowders were synthesized via sol gel method using gelatin as polymerization agent calcined at different temperatures of 500, 600, and 700 Degree-Sign C for 8 h. The prepared samples were characterized using X-ray diffraction and transition electron microscopy. The microleakage and antibacterial properties of the prepared samples were investigated and compared with zinc oxide eugenol (ZOE) and epoxy resin sealer (AH26), which are commonly used in dentistry as sealers. The results showed that the synthesized pure ZnO and ZnO:Ag nanopowders exhibit better microleakage and antibacterial properties in comparison with ZOE and AH26 sealers, and therefore are more suitable filling materials to be used as sealer in root canal treatment.

  16. Microleakage and antibacterial properties of ZnO and ZnO:Ag nanopowders prepared via a sol–gel method for endodontic sealer application

    International Nuclear Information System (INIS)

    Shayani Rad, M.; Kompany, A.; Khorsand Zak, A.; Javidi, M.; Mortazavi, S. M.

    2013-01-01

    One of the most important problems in dentistry is the microleakage, whether apical or coronal, which may cause failure of root canal therapy. The aim of this study is to prepare suitable sealer to decrease the microleakage of the root canals as well as having good antibacterial property. Pure ZnO and ZnO:Ag nanopowders were synthesized via sol gel method using gelatin as polymerization agent calcined at different temperatures of 500, 600, and 700 °C for 8 h. The prepared samples were characterized using X-ray diffraction and transition electron microscopy. The microleakage and antibacterial properties of the prepared samples were investigated and compared with zinc oxide eugenol (ZOE) and epoxy resin sealer (AH26), which are commonly used in dentistry as sealers. The results showed that the synthesized pure ZnO and ZnO:Ag nanopowders exhibit better microleakage and antibacterial properties in comparison with ZOE and AH26 sealers, and therefore are more suitable filling materials to be used as sealer in root canal treatment

  17. Structural and optical properties of Tb and Na-Tb co-doped Ca3V2O8 phosphors prepared by sol-gel process

    Science.gov (United States)

    Parab, Shambhu S.; Salker, A. V.

    2018-01-01

    A malic acid assisted sol-gel route was successfully employed to prepare two distinct series of green emitting Ca3V2O8 phosphors. In the first series, Tb was solely doped whereas in the second series Na and Tb were doped simultaneously in the Ca3V2O8 crystal lattice. X-ray diffraction studies proved the utility of adopted preparative method by confirming the monophasic formation of all compounds from both the series. Spectral analysis like Raman spectroscopy, UV-DRS were undertaken to analyse the local structure, crystallinity and absorptive characteristics. XPS validated the presence of desired oxidation states of all the elements present. Finally, photoluminescence studies were done to elucidate the scope of prepared compounds as green emitting phosphors and also to understand the effect of both doping schemes on the luminescence. Intense green emission was observed in both the cases. Tb concentration of 0.08 was found to be optimum in case of Tb singly doped compounds whereas Tb = 0.12 showed highest intensity among the Na-Tb co-doped samples. Moreover, a red shift in the excitation wavelength was observed after Na doping signifying a change in the local electronic environment which in turn has affected the luminescence pattern. Local crystallinity and vacancy concentrations were found to have a major say on the emission intensities.

  18. Preparation and in vitro/in vivo evaluation of antimicrobial ocular in situ gels containing a disappearing preservative for topical treatment of bacterial conjunctivitis.

    Science.gov (United States)

    Saher, Osama; Ghorab, Dalia M; Mursi, Nadia M

    2016-08-01

    The study aimed to formulate and evaluate levofloxacin hemihydrate ocular in situ gels along with freshly prepared disappearing preservative reported to be safer to human eyes. Formulae were prepared using thermosensitive (PF127 and PF68) or ion-activated (Gelrite) polymers. They were evaluated for gelation temperature (GT), capacity, content uniformity, pH, rheological behavior, in vitro drug release with kinetic analysis. Best formulae were exposed to storage effect to select the optimum formula that was subjected to different sterilization methods and in vivo evaluation. The prepared disappearing preservative (sodium perborate monohydrate) proved to be active oxidative preservative and compatible with our formulae. F9 (24% PF127, 15% PF 68, 0.5% levofloxacin hemihydrate, and 0.0025% sodium perborate monohydrate) showed prolonged drug release (12 h), acceptable GT, viscosity, and pH. It remained stable over 3 months at two temperatures and was best sterilized by filtration. It showed longer residence time (12 h) in rabbits' eye fluids compared with the Levoxin® eye drops (4 h). This successful attempt of using thermo-gelling system along with a disappearing type of preservatives would allow the use of these systems to achieve sustained release of antimicrobial drugs with minimum risk of eye damage improving patient compliance and treatment efficacy.

  19. Oxidation stability of biodiesel fuel as prepared by supercritical methanol

    Energy Technology Data Exchange (ETDEWEB)

    Jiayu Xin; Hiroaki Imahara; Shiro Saka [Kyoto University, Kyoto (Japan). Department of Socio-Environmental Energy Science, Graduate School of Energy Science

    2008-08-15

    A non-catalytic supercritical methanol method is an attractive process to convert various oils/fats efficiently into biodiesel. To evaluate oxidation stability of biodiesel, biodiesel produced by alkali-catalyzed method was exposed to supercritical methanol at several temperatures for 30 min. As a result, it was found that the tocopherol in biodiesel is not stable at a temperature higher than 300{sup o}C. After the supercritical methanol treatment, hydroperoxides were greatly reduced for biodiesel with initially high in peroxide value, while the tocopherol slightly decreased in its content. As a result, the biodiesel prepared by the supercritical methanol method was enhanced for oxidation stability when compared with that prepared by alkali-catalyzed method from waste oil. Therefore, supercritical methanol method is useful especially for oils/fats having higher peroxide values. 32 refs., 8 figs., 3 tabs.

  20. Nanostructured Mesoporous Titanium Dioxide Thin Film Prepared by Sol-Gel Method for Dye-Sensitized Solar Cell

    Directory of Open Access Journals (Sweden)

    Yu-Chang Liu

    2011-01-01

    Full Text Available Titanium dioxide (TiO2 paste was prepared by sol-gel and hydrothermal method with various precursors. Nanostructured mesoporous TiO2 thin-film back electrode was fabricated from the nanoparticle colloidal paste, and its performance was compared with that made of commercial P25 TiO2. The best performance was demonstrated by the DSSC having a 16 μm-thick TTIP-TiO2 back electrode, which gave a solar energy conversion efficiency of 6.03%. The ability of stong adhesion on ITO conducting glass substrate and the high surface area are considered important characteristics of TiO2 thin film. The results show that a thin film with good adhesion can be made from the prepared colloidal paste as a result of alleviating the possibility of electron transfer loss. One can control the colloidal particle size from sol-gel method. Therefore, by optimizing the preparation conditions, TiO2 paste with nanoparticle and narrow diameter distribution was obtained.

  1. Optical and structural properties of ZnO/ZnMgO composite thin films prepared by sol–gel technique

    International Nuclear Information System (INIS)

    Xu, Linhua; Su, Jing; Chen, Yulin; Zheng, Gaige; Pei, Shixin; Sun, Tingting; Wang, Junfeng; Lai, Min

    2013-01-01

    Highlights: ► ZnMgO thin film and ZnO/ZnMgO composite thin film have been prepared by sol–gel method. ► The intensity of ultraviolet emission of ZnMgO thin film is enhanced two times compared with that of pure ZnO thin film. ► Compared with ZnMgO thin film, ZnO/ZnMgO composite thin film shows better crystallization and optical properties. ► ZnO/ZnMgO composite thin films prepared by sol–gel method have potential applications in many optoelectronic devices. - Abstract: In this study, pure ZnO thin film, Mg-doped ZnO (ZnMgO) thin film, ZnO/ZnMgO and ZnMgO/ZnO composite thin films were prepared by sol–gel technique. The structural and optical properties of the samples were analyzed by X-ray diffraction, scanning electron microscopy, UV–visible spectrophotometer, ellipsometer and photoluminescence spectra, respectively. The results showed that the incorporation of Mg increased the strain, broadened the optical bandgap, and improved the intensity of ultraviolet emission of ZnO thin film. The full width at half maximum (FWHM) of the ultraviolet emission peak was also increased due to Mg-doping at the same time. Compared with pure ZnO and ZnMgO thin films, the ZnO/ZnMgO thin film showed better crystalline quality and ultraviolet emission performance, smaller strains and higher transmittance in the visible range.

  2. Ammonia sensing properties of V-doped ZnO:Ca nanopowders prepared by sol–gel synthesis

    International Nuclear Information System (INIS)

    Fazio, E.; Hjiri, M.; Dhahri, R.; El Mir, L.; Sabatino, G.; Barreca, F.; Neri, F.; Leonardi, S.G.; Pistone, A.; Neri, G.

    2015-01-01

    V-doped ZnO:Ca nanopowders with different V loading were prepared by sol–gel synthesis and successive drying in ethanol under supercritical conditions. Characterization data of nanopowders annealed at 700 °C in air, revealed that they have the wurtzite structure. Raman features of V-doped ZnO:Ca samples were found to be substantially modified with respect to pure ZnO or binary ZnO:Ca samples, which indicate the substitution of vanadium ions in the ZnO lattice. The ammonia sensing properties of V-doped ZnO:Ca thick films were also investigated. The results obtained demonstrate the possibility of a fine tuning of the sensing characteristics of ZnO-based sensors by Ca and V doping. In particular, their combined effect has brought to an enhanced response towards NH 3 compared to bare ZnO and binary V-ZnO and Ca-ZnO samples. Raman investigation suggested that the presence of Ca play a key role in enhancing the sensor response in these ternary composite nanomaterials. - Graphical abstract: V-doped ZnO:Ca nanopowders prepared by sol–gel synthesis possess enhanced sensing characteristics towards NH 3 compared to bare ZnO. - Highlights: • V-doped ZnO:Ca nanopowders with different V loading were prepared by sol–gel synthesis. • Raman features of V-doped ZnO:Ca samples indicate the substitution of V ions in the ZnO lattice. • Combined effects of dopants have brought to an enhanced response to NH 3 compared to ZnO. • Ca play a key role in enhancing the sensor response of ternary V-doped ZnO:Ca composites

  3. Laser ablation inductively coupled plasma mass spectrometry analysis of agricultural soils using the sol-gel technique of pellet preparation

    International Nuclear Information System (INIS)

    Hubova, I.; Hola, M.; Vaculovic, T.; Pinkas, J.; Prokes, L.; Stefan, I.; Kanicky, V.

    2009-01-01

    Full text: Monitoring of metals in agricultural soils is gaining importance as they are accumulated by plants. A LAICPQMS method with Nd:YAG 213 nm laser has been developed for determination of Cr, Ni, Cu, Zn and Pb in soil pellets prepared by the sol-gel technique. LA-ICPMS analysis of archive samples was verified by XRF of wax-soil pellets and ICPMS with nebulization of solutions obtained by total soil decomposition and by analysis of reference materials. Sequention extraction was used for fractionation analysis. (author)

  4. Influence of temperature in TL signal induced by gamma radiation in zircon prepared by sol gel via

    International Nuclear Information System (INIS)

    Salas, P.; Castano, V.M.; Mendoza A, D.; Gonzalez M, P.R.; Rosa C, E. de la

    2000-01-01

    In this work, it was realized a study of the temperature effects in thermoluminescent signal (Tl) induced by gamma radiation in zircon, which was prepared by the sol gel method. According to the obtained results, the zircon thermically treated at 500 C or over is sensitive to radiation. This sensitivity is increased when the temperature in study is augmented, moreover, the Tl spectra form also is modified with the temperature increment. The samples thermically treated at 750 C or over present a linear response in the dose interval 27 to 165 Gy; therefore, such materials result promissories for dosimetric purposes. (Author)

  5. Characteristics of nano Ti-doped SnO2 powders prepared by sol-gel method

    International Nuclear Information System (INIS)

    Liu, X.M.; Wu, S.L.; Chu, Paul K.; Zheng, J.; Li, S.L.

    2006-01-01

    Ti 4+ -doped SnO 2 nano-powders were prepared by the sol-gel process using tin tetrachloride and titanium tetrachloride as the starting materials. The crystallinity and purity of the powders were analyzed by X-ray diffraction (XRD) and the size and distribution of Ti 4+ -doped SnO 2 grains were studied using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The results show that Ti 4+ has been successfully incorporated into the SnO 2 crystal lattice and the electrical conductivity of the doped materials improves significantly

  6. Purification and preparation of graphite oxide from natural graphite

    Energy Technology Data Exchange (ETDEWEB)

    Panatarani, C., E-mail: c.panatarani@phys.unpad.ac.id; Muthahhari, N.; Joni, I. Made [Instrumentation Systems and Functional Material Processing Laboratory, Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Padjadjaran University, Jl. Raya Bandung-Sumedang KM 21, Jatinangor, 45363, Jawa Barat (Indonesia); Rianto, Anton [Grafindo Nusantara Ltd., Belagio Mall Lantai 2, Unit 0 L3-19, Kawasan Mega Kuningan, Kav. B4 No.3, Jakarta Selatan (Indonesia)

    2016-03-11

    Graphite oxide has attracted much interest as a possible route for preparation of natural graphite in the large-scale production and manipulation of graphene as a material with extraordinary electronic properties. Graphite oxide was prepared by modified Hummers method from purified natural graphite sample from West Kalimantan. We demonstrated that natural graphite is well-purified by acid leaching method. The purified graphite was proceed for intercalating process by modifying Hummers method. The modification is on the reaction time and temperature of the intercalation process. The materials used in the intercalating process are H{sub 2}SO{sub 4} and KMNO{sub 4}. The purified natural graphite is analyzed by carbon content based on Loss on Ignition test. The thermo gravimetricanalysis and the Fouriertransform infrared spectroscopy are performed to investigate the oxidation results of the obtained GO which is indicated by the existence of functional groups. In addition, the X-ray diffraction and energy dispersive X-ray spectroscopy are also applied to characterize respectively for the crystal structure and elemental analysis. The results confirmed that natural graphite samples with 68% carbon content was purified into 97.68 % carbon content. While the intercalation process formed a formation of functional groups in the obtained GO. The results show that the temperature and reaction times have improved the efficiency of the oxidation process. It is concluded that these method could be considered as an important route for large-scale production of graphene.

  7. Preparation and characterization of silk/silica hybrid biomaterials by sol-gel crosslinking process

    Energy Technology Data Exchange (ETDEWEB)

    Hou Aiqin, E-mail: aiqinhou@dhu.edu.c [National Engineering Research Center for Dyeing and Finishing of Textiles, Donghua University, 3H, 2999 North Renmin Road, Songjiang, Shanghai 201620 (China); Chen Huawei [National Engineering Research Center for Dyeing and Finishing of Textiles, Donghua University, 3H, 2999 North Renmin Road, Songjiang, Shanghai 201620 (China)

    2010-03-15

    The silk/silica hybrid biomaterials are synthesized by sol-gel crosslinking process. The chemical and morphological structures of silk/silica hybrids are investigated with micro-FT-IR spectra, X-ray diffraction, SEM, AFM, and DSC. The results show that the crosslinking reactions among inorganic nano-particles, fibroin and 2,4,6-tri[(2-epihydrin-3-bimethyl-ammonium)propyl]-1,3,5-triazine chloride (Tri-EBAC) take place during sol-gel process. The silk/silica hybrids form new molecular structures containing not only organic fibroin but also inorganic nano-silica particles. The inorganic particles are bounded to the fibroin through covalent bonds. The silk/silica hybrids can form excellent film with very even nanometer particles. The thermal properties of organic/inorganic hybrid are improved.

  8. Preparation and characterization of silk/silica hybrid biomaterials by sol-gel crosslinking process

    International Nuclear Information System (INIS)

    Hou Aiqin; Chen Huawei

    2010-01-01

    The silk/silica hybrid biomaterials are synthesized by sol-gel crosslinking process. The chemical and morphological structures of silk/silica hybrids are investigated with micro-FT-IR spectra, X-ray diffraction, SEM, AFM, and DSC. The results show that the crosslinking reactions among inorganic nano-particles, fibroin and 2,4,6-tri[(2-epihydrin-3-bimethyl-ammonium)propyl]-1,3,5-triazine chloride (Tri-EBAC) take place during sol-gel process. The silk/silica hybrids form new molecular structures containing not only organic fibroin but also inorganic nano-silica particles. The inorganic particles are bounded to the fibroin through covalent bonds. The silk/silica hybrids can form excellent film with very even nanometer particles. The thermal properties of organic/inorganic hybrid are improved.

  9. Modified sol–gel preparation of LiNbO.sub.3./sub. target for PLD

    Czech Academy of Sciences Publication Activity Database

    Jakeš, V.; Rubešová, V.; Erben, J.; Nekvindová, P.; Jelínek, Miroslav

    2013-01-01

    Roč. 35, č. 12 (2013), s. 2540-2543 ISSN 0925-3467 R&D Projects: GA ČR(CZ) GAP106/10/1477 Institutional support: RVO:68378271 Keywords : lithium niobate * PLD * sol–gel * Pechini polyesterification * transmittance Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.075, year: 2013 http://dx.doi.org/10.1016/j.optmat.2013.07.019

  10. Performance of the sol-gel method for the preparation of optical fibers

    Czech Academy of Sciences Publication Activity Database

    Matějec, Vlastimil; Hayer, Miloš; Mrázek, Jan; Kašík, Ivan; Podrazký, Ondřej; Pospíšilová, Marie

    2007-01-01

    Roč. 52, č. 10 (2007), s. 991-998 ISSN 0035-3930. [Physical Chemistry Conference ROMPHYSCHEM /12./. Bucharest, 06.09.2006-08.09.2006] R&D Projects: GA ČR GA102/05/0956 Institutional research plan: CEZ:AV0Z20670512 Keywords : sol-gel processing * optical fibres * chemical sensors Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.262, year: 2007

  11. Development of cobalt ferrite powder preparation employing the sol-gel technique and its structural characterization

    International Nuclear Information System (INIS)

    Sajjia, M.; Oubaha, M.; Prescott, T.; Olabi, A.G.

    2010-01-01

    Research highlights: This work focuses on the sol-gel process and the effects that the initial parameters have on the final product, which is the cobalt ferrite powder, in addition to the heat treatment. Particular interest is devoted to understand how the crosslinker and the chelating agent work and affect the final product. - Abstract: This work focuses on the development of a method to make cobalt ferrite powder using the sol-gel process. A particular emphasis is devoted to the understanding of the role of the chemical parameters involved in the sol-gel technique, and of the heat treatment on the structures and morphologies of the materials obtained. Several samples of cobalt ferrite powder were obtained by varying the initial parameters of the process in addition to the heat treatment temperature. X-ray diffraction and scanning electron microscopy were used to identify the structure and morphology of samples demonstrating the influence of the initial parameters. DTA/TGA was carried out on two standard samples to identify important reaction temperatures during the heat treatment. The average size of the nano crystallites was estimated for a sample by the full width at half maximum (FWHM) of the strongest X-ray diffraction (XRD) peak. It has been found that the chelating agent and the crosslinker have a critical influence on the resultant structure, the particle size and the particle size distribution.

  12. Evaluation of preparation and performance of gel column 99Tcm generators based on zirconium molybdate - 99Mo

    International Nuclear Information System (INIS)

    Saraswathy, P.; Sarkar, S.K.; Patel, R.R.; Arora, S.S.; Arjun, G.; Narasimhan, D.V.S.; Ramamoorthy, N.

    1998-01-01

    In view of the importance and relevance of zirconium molybdate (ZrMo) based gel generators for 99 Tc m , developed first by Australian scientists, particularly for developing nations having production capability for neutron activated 99 Mo, work has been carried out in our centre towards optimisation of the preparatory conditions. Appropriate facilities have been set up for safe, reliable and regular manufacture of such 99 Tc m gel generators on a small scale based on our earlier successful attempts on the approach for process standardisation. The results of our extensive evaluation, including for clinical use, are reported here. Following the regular procedure standardised by us earlier, 9 lots of 99 Mo were converted in ZrMo gel adopting aseptic practices and two different techniques for drying the ZrMo cake - heated air at 60-80 deg. C and microwave drying at 385 watts. The ZrMo granules obtained after further processing were loaded onto generator assemblies. 10 g molybdenum was handled in each batch of gel conversion, while typically 2 g Mo was used per generator column, except in the case of demonstration of higher capacity generators. The generator performance was evaluated systematically over nearly 15 days, in terms of rapidity and smoothness of elution, 99 Tc m elution yield and quality of eluted pertechnetate. The consistent results of over 60% (Max. 90%) yield of 99 Tc m , -3 % 99 Mo breakthrough, >98% radiochemical purity of pertechnetate, 99 Tc m compounds etc. indicated satisfactory quality of pertechnetate, comparable to that obtained by conventional generator systems. 12 such generators, containing up to 18.5 GBq 99 Mo, supplied for clinical use and evaluated at two hospital radiopharmacies showed satisfactory generator performance. The applicability for preparing larger capacity generators for centralised radiopharmacies and feasibility to achieve reduced process time and ease of control by using microwave oven drying have been established. (author)

  13. Deposition of tin oxide doped with fluorine produced by sol-gel method and deposited by spray-pyrolysis

    International Nuclear Information System (INIS)

    Maia, Paulo Herbert Franca; Lima, Francisco Marcone; Sena, Aline Cosmo de; Silva, Alvaro Neuton; Almeida, Ana Fabiola Leite de; Freire, Francisco Nivaldo Aguiar

    2014-01-01

    Solar energy is one of the most important sources of renewable energy today, but its production is based on silicon cells, expensive and difficult to produce, so the research seek new materials to replace them. This work aims to deposit tin oxide doped with fluorine on the glass substrate using the sol-gel method to provide a working solution and spray pyrolysis technique to perform the deposition. F-SnO2 (FTO) were synthesized by sol-gel method, employing NH_4F and SnCl_2 precursor in an ethanol solution. Before the formation of the gel phase, the entire solution was sprayed, with the aid of a pistol aerographic substrate under heated at 600 °C divided by 50 applications and cooled in the furnace. The substrates had resistances between 10 and 30 S.cm. The energy dispersive x-ray (EDS) revealed the presence of fluorine in the SnO_2 network. (author)

  14. Study of gels of molybdenum with cerium in the preparation of generators of {sup 99}Mo-{sup 99m}Tc

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Vanessa; Marczewski, Barbara; Dias, Carla Roberta; Osso Junior, Joao Alberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), SP (Brazil). Centro de Radiofarmacia

    2005-10-15

    {sup 99m} Tc has ideal nuclear properties for organ imaging in nuclear medicine, and it is obtained from the {sup 99}Mo-{sup 99m} Tc generator. Four different types of generators are available: chromatographic that uses {sup 99}Mo from fission of uranium; MEK solvent extraction; Tc{sub 2}O{sub 7} sublimation; gel chromatographic. This work presents the preparation of gel generators of molybdenum with cerium and characterization of the gels: mass ratio between molybdenum and cerium, structure, size of particles and elution percentage of {sup 99m} Tc after irradiating the gels. Eight gels were prepared at the same temperature of 50 deg C with concentrations of NaOH of 2 and 4 mol/L, mass ratio of 0.31 and 0.38 and final pH of 3.5 and 4.5. The analysis of the results proved that these gels are not adequate for preparation of the generators of {sup 99}Mo-{sup 99m} Tc, since the elution percentages are low, when compared with the gel of molybdenum with zirconium.(author)

  15. Preparation and studies of Eu3+ and Tb3+ co-doped Gd2O3 and Y2O3 sol-gel scintillating films

    International Nuclear Information System (INIS)

    Morales Ramirez, A. de J; Garcia Murillo, A.; Carrillo Romo, F. de J; Ramirez Salgado, J.; Le Luyer, C.; Chadeyron, G.; Boyer, D.; Moreno Palmerin, J.

    2009-01-01

    Eu 3+ (2.5 at.%) and Tb 3+ (0.005-0.01 at.%) co-doped gadolinium and yttrium oxide (Gd 2 O 3 and Y 2 O 3 ) powders and films have been prepared using the sol-gel process. High density and optical quality thin films were prepared with the dip-coating technique. Gadolinium (III) 2,4-pentadionate and yttrium (III) 2,4-pentadionate were used as precursors, and europium and terbium in their nitrate forms were used as doping agents. Chemical and structural analyses (infrared spectroscopy, X-ray diffraction and high-resolution transmission electron microscopy) were conducted on both sol-gel precursor powders and dip-coated films. The morphology of thin films heat-treated at 700 o C was studied by means of atomic force microscopy. It was shown that the highly dense and very smooth films had a root mean roughness (RMS) of 2 nm ± 0.2 (A = 0.0075 Tb 3+ ) and 24 nm ± 3.0 (B = 0.01 Tb 3+ ). After treatment at 700 o C, the crystallized films were in the cubic phase and presented a polycrystalline structure made up of randomly oriented crystallites with grain sizes varying from 20 to 60 nm. The X-ray induced emission spectra of Eu 3+ - and Tb 3+ -doped Gd 2 O 3 and Y 2 O 3 powders showed that Tb 3+ contents of 0.005, 0.0075 and 0.01 at.% affected their optical properties. Lower Tb 3+ concentrations (down to 0.005 at.%) in both systems enhanced the light yield.

  16. One-pot synthesis of a graphene oxide coated with an imprinted sol–gel for use in electrochemical sensing of paracetamole

    International Nuclear Information System (INIS)

    Luo, Jing; Cong, Jiaojiao; Fang, Ruixue; Fei, Xiaoma; Liu, Xiaoya

    2014-01-01

    A route is described for the preparation of a composite consisting of graphene oxide and a molecularly imprinted sol–gel polymer (GO/MIPs) through one-pot room temperature polymerization in aqueous solution. The material was obtained by mixing graphene oxide with the monomers (phenyltriethoxysilane and tetramethoxysilane) and the template paracetamole, followed by sol–gel copolymerization and extraction. The monomer and template concentrations and the incubation time were optimized. The composite was characterized by FTIR, TGA, XRD, Raman spectroscopy and SEM. It was then deposited as a thin film acting as a molecular recognition element on a glassy carbon electrode to obtain an electrochemical sensor for paracetamole. The electrode displayed an excellent recognition capacity toward paracetamole compared to its analogs. The peak current is linearly proportional to the concentration of paracetamole in the 0.1 μM to 80 μM range, and the detection limit is 20 nM (at an SNR of 3). Hence, this electrode possesses a wider response range and lower detection limit compared to most previously reported electrochemical sensors for paracetamole. It also exhibits excellent stability and has been successfully used to determine paracetamole in tablets and spiked human urine samples. (author)

  17. Analysis on the factors affecting the preparation of TIO2-ADUN composite sol by sol-gel method

    International Nuclear Information System (INIS)

    Wang Hui; Yin Rongcai; Liu Jinhong

    2010-01-01

    With C 2 H 2 O 5 and water as solvent and TBT as precursor and HNO 3 as the activator and valorize, the process for preparing TiO 2 -ADUN composite Sol method was studied. The influence of different reaction conditions on Sol-Gel time was analyzed in this study. The optimal reaction condition are: reaction temperature 20-25 degree C; pH value of reaction mixture 2-5; HNO 3 value of reaction mixture 0.3-0.5 ml; molar rations of alcohol to TBT 10, of water to TBT 2-3, respectively. A concentrated ADUN solution with Ti Sol , urea, water as additive is dispersed into uniform which are prepared by external mlii. (authors)

  18. Effects of sintering temperature on structural and electrical transport properties of zinc ferrites prepared by sol-gel route

    International Nuclear Information System (INIS)

    Anis-ur-Rehman, M.; Malik, M.A.; Ahmad, I.; Nasir, S.; Mubeen, M.; Abdullah, A.

    2011-01-01

    The effects of sintering temperature on the structural and electrical transport properties of nanocrystalline zinc ferrites are reported. The zinc ferrites were prepared by WOWS sol-gel synthesis route. The prepared sample was sintered at temperatures 500 deg. C, 700 deg. C and 900 deg. C respectively for 2 h. X-ray Diffraction (XRD) technique was used to describe the structural properties. The crystallite size, lattice parameters and porosity of samples were measured from the analysis of XRD data. The average crystallite size for each sample was measured using the Scherrer formula by considering the most intense (3 1 1) peak. The dielectric constant (e), dielectric loss tangent (tan theta ) and AC electrical conductivity of nanocrystalline Zn ferrites are investigated as a function of frequency and sintering temperature. All the electrical properties are explained in accordance with MaxwellWagner model and Koops phenomenological theory. (author)

  19. Ionic liquids in a poly ethylene oxide cross-linked gel polymer as an electrolyte for electrical double layer capacitor

    Science.gov (United States)

    Chaudoy, V.; Tran Van, F.; Deschamps, M.; Ghamouss, F.

    2017-02-01

    In the present work, we developed a gel polymer electrolyte via the incorporation of a room temperature ionic liquid into a cross-linked polymer matrix. The cross-linked gel electrolyte was prepared using a free radical polymerization of methacrylate and dimethacrylate oligomers dissolved in 1-propyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide. Combining the advantages of the ionic liquids and of conventional polymers, the cross-linked gel polymer electrolyte was used both as a separator and as an electrolyte for a leakage-free and non-flammable EDLC supercapacitor. The quasi-all solid-state supercapacitors showed rather good capacitance, power and energy densities by comparison to a liquid electrolyte-based EDLC.

  20. Biodiesel production using alkali earth metal oxides catalysts synthesized by sol-gel method

    Directory of Open Access Journals (Sweden)

    Majid Mohadesi

    2014-03-01

    Full Text Available Biodiesel fuel is considered as an alternative to diesel fuel. This fuel is produced through transesterification reactions of vegetable oils or animal fat by alcohols in the presence of different catalysts. Recent studies on this process have shown that, basic heterogeneous catalysts have a higher performance than other catalysts. In this study different alkali earth metal oxides (CaO, MgO and BaO doped SiO2 were used as catalyst for the biodiesel production process. These catalysts were synthesis by using the sol-gel method. A transesterification reaction was studied after 8h by mixing corn oil, methanol (methanol to oil molar ratio of 16:1, and 6 wt. % catalyst (based on oil at 60oC and 600rpm. Catalyst loading was studied for different catalysts ranging in amounts from 40, 60 to 80%. The purity and yield of the produced biodiesel for 60% CaO/SiO2 was higher than other catalysts and at 97.3% and 82.1%, respectively.

  1. [In vitro evaluation of the gels properties prepared on Pluronic F-127 as vehicles for administration prolactin by injection].

    Science.gov (United States)

    Karolewicz, Bozena; Pawlik-Gałczyńska, Anna; Pluta, Janusz; Ryszka, Florian

    2011-01-01

    The aim of this study was to prepare a thermoresponsive formulations, which are a carrier for proteins--prolactin administered directly into solid tumor and which obtain sol-gel transitions at physiological ranges of temperature. Prolactin (PRL) is a hormone that in vivo and in vitro exhibits antiangiogenic properties. Application of this protein in the proposed formulations can be particularly advantageous because of its relatively low stability and limited ability to transmembrane penetration. The paper prepared thermoresponsive carriers, based on nonionic polymer Pluronic F-127 with selected excipients such as dextran 7000, PEG 400, Tween 20 and Tween 80. The sol-gel transition temperature of the formulations was investigated and their physicochemical properties such as pH, density, osmotic pressure were studied. In the remainder of the work carried out tests of prolactin release from the proposed media. The results obtained indicate that a significant influence on the theological parameters obtained carriers and the availability of pharmaceutical composition of prolactin was developed formulation.

  2. Effect of various lanthanum sol-gel coatings on the 330Cb (Fe-35Ni-18Cr-1Nb-2Si) oxidation at 900 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Buscail, H., E-mail: buscail@iut.u-clermont1.fr [Clermont Universite- LVEEM, 8 rue J.B. Fabre, BP 219, 43006 Le Puy en Velay (France); Issartel, C.; Riffard, F.; Rolland, R.; Perrier, S. [Clermont Universite- LVEEM, 8 rue J.B. Fabre, BP 219, 43006 Le Puy en Velay (France); Fleurentin, A. [CETIM, 52 av Felix Louat, BP 80067, 60304 Senlis (France); Josse, C. [L' ICB UMR5209 CNRS, BP 47870, 21078 Dijon (France)

    2011-11-01

    The influence of a lanthanum sol-gel coating on the oxide scale adherence has been studied during the 330Cb (Fe-35Ni-18Cr-1Nb-2Si) oxidation at 900 deg. C, in air. The alloy oxidation is performed in order to generate a protective chromia scale acting as a good barrier against carburization. Argon annealing of lanthanum sol-gel coatings have been performed at various temperatures in order to find the best conditions to insure the scale adherence. Kinetic results show that lanthanum sol-gel coatings lead to a lower oxidation rate compared to blank specimens. Thermal cycling tests on lanthanum the sol-gel coated specimen show that the oxide scale formed at 900 deg. C, in air, is adherent.

  3. Inhibition of interaction between epigallocatechin-3-gallate and myofibrillar protein by cyclodextrin derivatives improves gel quality under oxidative stress.

    Science.gov (United States)

    Zhang, Yumeng; Chen, Lin; Lv, Yuanqi; Wang, Shuangxi; Suo, Zhiyao; Cheng, Xingguang; Xu, Xinglian; Zhou, Guanghong; Li, Zhixi; Feng, Xianchao

    2018-06-01

    High levels of polyphenols can interact with myofibrillar proteins (MPs), causing damage to a MP emulsion gel. In this study, β-cyclodextrins were used to reduce covalent and non-covalent interaction between epigallocatechin-3-gallate (EGCG) and MPs under oxidative stress. The loss of both thiol and free amine groups and the unfolding of MPs caused by EGCG (80 μM/g protein) were significantly prevented by β-cyclodextrins, and the structural stability and solubility were improved. MP emulsion gel treated with EGCG (80 μM/g protein) had the highest cooking loss (68.64%) and gel strength (0.51 N). Addition of β-cyclodextrins significantly reduced cooking loss (26.24-58.20%) and improved gel strength (0.31-0.41 N) of MP emulsion gel jeopardized by EGCG under oxidative stress. Damage to the emulsifying properties of MPs caused by EGCG was significantly prevented by addition of β-cyclodextrins. β-cyclodextrins reduced interaction between EGCG and MPs in the order Methyl-β-cyclodextrin > (2-Hydroxypropyl)-β-cyclodextrin > β-cyclodextrin. In absence of EGCG, addition of β-cyclodextrins partly protected MPs from oxidative attack and improved its solubility. It is concluded that β-cyclodextrins does not markedly reduce the antioxidant ability of EGCG according to carbonyl analysis, and can effectively increase EGCG loading to potentially provide more durable antioxidant effect for meat products during processing, transportation and storage. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Preparation and Characterization of Promoted Fe-V/SiO2 Nanocatalysts for Oxidation of Alcohols

    Directory of Open Access Journals (Sweden)

    Hamid Reza Rafiee

    2013-01-01

    Full Text Available A series of SiO2 supported iron-vanadium catalysts were prepared using sol-gel and wetness impregnation methods. This research investigates the effects of V and Cu on the structure and morphology of Fe/SiO2 catalysts. The SiO2 supported catalyst with the highest specific surface area and pore volume was obtained when it is containing 40 wt.% Fe, 15 wt.% V, and 2 wt.% Cu. Characterization of prepared catalysts was carried out by powder X-ray diffraction (XRD, scanning electron microcopy (SEM, vibrating sample magnetometry (VSM, Fourier transform infrared (FT-IR spectrometry, temperature program reduction (TPR, N2 physisorption, and thermal analysis methods such as thermal gravimetric analysis (TGA and differential scanning calorimetry (DSC. The Fe-V/SiO2 catalyst promoted with 2 wt.% of Cu exhibited typical ferromagnetic behavior at room temperature with a saturation magnetization value of 11.44 emu/g. This character of catalyst indicated great potential for application in magnetic separation technologies. The prepared catalyst was found to act as an efficient recoverable nanocatalyst for oxidation reaction of alcohols to aldehydes and ketones in aqueous media under mild condition. Moreover, the catalyst was reused five times without significant degradation in catalytic activity and performance.

  5. Effect of Sn doping on structural, mechanical, optical and electrical properties of ZnO nanoarrays prepared by sol-gel and hydrothermal process

    Science.gov (United States)

    Agarwal, Manish Baboo; Sharma, Akash; Malaidurai, M.; Thangavel, R.

    2018-05-01

    Undoped and Sn doped Zinc oxide nanorods were prepared by two step process: initially growth of seed layers by sol-gel spin coating technique and then zinc oxide nanorods by hydrothermal process using the precursors zinc nitrate hexahydrate, hexamine and tin chloride. The effects on the electrical, optical, mechanical and structural properties for various Sn concentrations were studied. The crystalline phase determination from X-ray diffraction (XRD) confirms that Sn doped ZnO nanorods have hexagonal wurtzite structure. The variations of stress and strain with different doping concentration of Sn in ZnO nanorods were studied. The doping effect on electrical properties and optical bandgap is estimated by current voltage characteristics and absorbance spectra respectively. The surface morphology was studied with field emission scanning electron microscope (FESEM), which shows that the formation of hexagonal nanorods arrays with increasing Sn concentration. The calculated value of Young's modulus of elasticity (Y) for all the samples remains same. These results can be used in optoelectronic devices.

  6. Preparation of micro-porous gel polymer for lithium ion polymer battery

    International Nuclear Information System (INIS)

    Kim, Je Young; Kim, Seok Koo; Lee, Seung-Jin; Lee, Sang Young; Lee, Hyang Mok; Ahn, Soonho

    2004-01-01

    We have developed a micro-porous gelling polymer layer which is formed on both the sides of support polyolefin separator with wet or dry processing technique. Morphologies of gel-coated layer are dependent on the compositions and process conditions, such as solvent/non-solvent combination and stretching ratios. The micro-porous gelling layer is used for the assembly of the lithium ion polymer battery of LG Chemical Ltd. The structure of battery is given elsewhere and the battery has excellent discharge performance with 94% of 2C discharge performance at room temperature

  7. Synthesis by sol-gel and characterization of catalysts Ag/Al2O3- CeO2 for the elimination of nitric oxide

    International Nuclear Information System (INIS)

    Zayas R, M.L.

    2005-01-01

    The environmental pollution is one from the big problems to solve at the present time, because the quality of the alive beings life is affected. For such reason, more clean and economic technologies are required, that it conduces to develop new catalytic alternatives to diminish the nitrogen oxides that due to its chemical processes in the environment contribute considerably in the air pollution. The main objective of the present work, is the preparation and characterization of catalytic materials with base of silver supported in simple and mixed aluminium oxides (Al 2 O 3 ) and Cerium oxide (CeO 2 ), and its catalytic evaluation that through of the reduction of nitric oxide (NO) using hydrogen (H 2 ) as reducer agent. It was synthesized alumina (Al 2 O 3 ) and Cerium oxide (CeO 2 ) and mixed oxides (Al 2 O 3 - CeO 2 ), by the sol-gel method and the cerium oxide (CeO 2 ) by precipitation of the cerium nitrate (III) hexa hydrated. The oxides were stabilized thermally at 900 C by 5 hr. The catalysts were prepared by impregnation using silver nitrate (AgNO 3 ), the nominal concentration of Ag was of 5% in weight. The catalysts were reduced at 400 C by 2 hr, in hydrogen flow of 60 cc/min. The characterization of the catalytic materials was carried out through different techniques as: nitrogen adsorption to determine the surface area BET, scanning electron microscopy (SEM) to observe the final morphology of the catalysts, X-ray diffraction (XRD) to identify the crystalline phases of the catalytic materials, Infrared spectroscopy (DRIFT) to know the structural characterization of the catalysts, reduction to programmed temperature (TPR) to evidence the interaction metal-support. The catalytic properties of the catalysts were evaluated in the model reaction NO + H 2 , to determine the activity and selectivity. The results indicate that the preparation technique, the precursors and the thermal treatments that underwent these materials influence in the catalyst and by

  8. Highly stable and imperceptible electronics utilizing photoactivated heterogeneous sol-gel metal-oxide dielectrics and semiconductors.

    Science.gov (United States)

    Jo, Jeong-Wan; Kim, Jaekyun; Kim, Kyung-Tae; Kang, Jin-Gu; Kim, Myung-Gil; Kim, Kwang-Ho; Ko, Hyungduk; Kim, Jiwan; Kim, Yong-Hoon; Park, Sung Kyu

    2015-02-18

    Incorporation of Zr into an AlOx matrix generates an intrinsically activated ZAO surface enabling the formation of a stable semiconducting IGZO film and good interfacial properties. Photochemically annealed metal-oxide devices and circuits with the optimized sol-gel ZAO dielectric and IGZO semiconductor layers demonstrate the high performance and electrically/mechanically stable operation of flexible electronics fabricated via a low-temperature solution process. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Structural studies on iron-tellurite glasses prepared by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Rada, S., E-mail: Simona.Rada@phys.utcluj.r [Department of Physics, Technical University of Cluj-Napoca, Bibliotecii, No. 10, 400020 Cluj-Napoca (Romania); Dehelean, A. [Department of Physics, Technical University of Cluj-Napoca, Bibliotecii, No. 10, 400020 Cluj-Napoca (Romania); Nat. Inst. for R and D of Isotopic and Molec. Technologies, Cluj-Napoca (Romania); Stan, M. [Nat. Inst. for R and D of Isotopic and Molec. Technologies, Cluj-Napoca (Romania); Chelcea, R. [Department of Physics, Technical University of Cluj-Napoca, Bibliotecii, No. 10, 400020 Cluj-Napoca (Romania); Nat. Inst. for R and D of Isotopic and Molec. Technologies, Cluj-Napoca (Romania); Culea, E. [Department of Physics, Technical University of Cluj-Napoca, Bibliotecii, No. 10, 400020 Cluj-Napoca (Romania)

    2011-01-05

    Research highlights: {yields} Iron-tellurite glasses obtained using the sol-gel synthesis. - Abstract: In this study, we report structural properties of the iron-tellurite glasses obtained using the sol-gel synthesis. The samples were characterized by X-ray diffraction, FTIR, UV-vis and EPR spectroscopy. Our results indicate dominant presence of iron ions in the trivalent state and the existence some Fe{sup 2+} ions. The analysis of the IR spectra indicates a gradual transformation of iron ions from tetrahedral into octahedral sites when the concentration of Fe(NO{sub 3}){sub 3} is increased beyond 0.64 mol%. EPR studies show that the increase of Fe(NO{sub 3}){sub 3} content in the host matrix induces the growth of the number of effective g values. This can be explained considering that the orbitals of O{sup 2-} ion with a large spin-orbit interaction constant will interact with the 3d orbital of Fe{sup 3+} ion bonded to this O{sup 2-} ion, thus leading to appearance of an orbital angular momentum which contributes to the magnetic moment of Fe{sup 3+} ion. A strong dipolar interaction, which is more predominant in a glass with higher content of Fe(NO{sub 3}){sub 3}, causing a localized magnetic field along the site of the Fe{sup 3+} ions and the increase the effective g values.

  10. Sol-gel preparation of Ag-silica nanocomposite with high electrical conductivity

    Science.gov (United States)

    Ma, Zhijun; Jiang, Yuwei; Xiao, Huisi; Jiang, Bofan; Zhang, Hao; Peng, Mingying; Dong, Guoping; Yu, Xiang; Yang, Jian

    2018-04-01

    Sol-gel derived noble-metal-silica nanocomposites are very useful in many applications. Due to relatively low price, higher conductivity, and higher chemical stability of silver (Ag) compared with copper (Cu), Ag-silica has gained much more research interest. However, it remains a significant challenge to realize high loading of Ag content in sol-gel Ag-silica composite with high structural controllability and nanoparticles' dispersity. Different from previous works by using multifunctional silicon alkoxide to anchor metal ions, here we report the synthesis of Ag-silica nanocomposite with high loading of Ag nanoparticles by employing acetonitrile bi-functionally as solvent and metal ions stabilizer. The electrical conductivity of the Ag-silica nanocomposite reached higher than 6800 S/cm. In addition, the Ag-silica nanocomposite could simultaneously possess high electrical conductivity and positive conductivity-temperature coefficient by properly controlling the loading content of Ag. Such behavior is potentially advantageous for high-temperature devices (like phosphoric acid fuel cells) and inhibiting the thermal-induced increase of devices' internal resistance. The strategy proposed here is also compatible with block-copolymer directed self-assembly of mesoporous material, spin-coating of film and electrospinning of nanofiber, making it more charming in various practical applications.

  11. Preparation of soft-agglomerated nano-sized ceramic powders by sol-gel combustion process

    International Nuclear Information System (INIS)

    Feng, Q.; Ma, X.H.; Yan, Q.Z.; Ge, C.C.

    2009-01-01

    The soft-agglomerated Gd 2 BaCuO 5 (Gd211) nano-powders were synthesized by sol-gel combustion process with binary ligand and the special pretreatment on gel. The mechanism of the formation of weakly agglomerated structure was studied in detail. The results showed that network structure in gelation process was found to be a decisive factor for preventing agglomeration of colloidal particles. The removal of free water, coordinated water, and most of hydroxyl groups during pretreatment further inhibited the formation of hydrogen bonds between adjacent particles. The soft-agglomeration of the particles was confirmed by isolated particles in calcined Gd211 powders and in green compact, a narrow monomodal pore size distribution of the green compact and the low agglomeration coefficient of the calcined Gd211 powder. Extension this process to synthesis of BaCeO 3 , BaTiO 3 and Ce 0.8 Sm 0.2 O 1.9 powders, also led to weakly agglomerated nano-powders. It suggests that this method represents a powerful and facile method for the creation of doped and multi-component nano-sized ceramic powders.

  12. Structural and optical characterization of nanoparticulate manganese doped zinc silicate phosphors prepared by sol–gel and combustion methods

    Energy Technology Data Exchange (ETDEWEB)

    Mbule, P.S., E-mail: mbuleps@gmail.com [Department of Physics, CSET, University of South Africa, Johannesburg, 1710 (South Africa); Ntwaeaborwa, O.M. [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein 9300 (South Africa); Mothudi, B.M.; Dhlamini, M.S. [Department of Physics, CSET, University of South Africa, Johannesburg, 1710 (South Africa)

    2016-11-15

    The present study reports the synthesis, crystallographic structure and optical properties of manganese (Mn{sup 2+}) doped zinc silicate (Zn{sub 2}SiO{sub 4}) nanoparticle phosphors prepared by sol–gel and combustion methods. For samples prepared by sol–gel method, the X-ray diffraction results showed phase transformation from amorphous to α-phase Zn{sub 2}SiO{sub 4} due to annealing temperatures at 600 °C to 1100 °C, whereas for combustion samples an admixture of highly crystalline β-phase and hexagonal wurtzite structure of ZnO was observed at annealing temperature of 600 °C. Photoluminescence spectra with Mn{sup 2+} concentrations ranging from 0.015–0.09 mol% were compared for two methods. Emission band assigned to the {sup 4}T{sub 1}({sup 4}G)→{sup 6}A{sub 1}({sup 6}S) electronic transition of Mn{sup 2+} was observed with maximum intensity at ~573 nm for combustion samples and ~532 nm for sol–gel samples upon UV-excitation by a Xenon lamp. Furthermore, the photoluminescence decay curves of annealed Zn{sub 2}SiO{sub 4}:Mn{sup 2+} samples were observed to be bi-exponential. The fast and slow decay components are due to the pair or cluster formation and isolated ions at higher doping concentration, respectively. - Highlights: • Synthesis, crystallographic and optical properties of Zn{sub 2}SiO{sub 4}:Mn{sup 2+} are presented. • XRD shows amorphous diffraction peak and crystallinity improved by increase of annealing temperature. • Crystallite and particle size from XRD and SAXS techniques, respectively, are compared. • Photoluminescence (PL) spectra are compared for sol-gel and combustion method. • The photoluminescence decay curves of annealed Zn{sub 2}SiO{sub 4}:Mn{sup 2+} samples were observed to be bi-exponential.

  13. Preparation of molybdenum oxide thin films by MOCVD

    International Nuclear Information System (INIS)

    Guerrero, R. Martinez; Garcia, J.R. Vargas; Santes, V.; Gomez, E.

    2007-01-01

    In this study, molybdenum oxide films were prepared in a horizontal hot-wall MOCVD apparatus using molybdenum dioxide acetylacetonate as precursor. The molybdenum precursor was synthesized from acetylacetone and molybdenum oxide powder. Thermal gravimetric (TG) and differential thermal analyses (DTA) of the precursor suggested the formation of molybdenum oxides around 430 o C (703 K). Thus, a range of deposition temperatures varying from 350 to 630 o C (623-903 K) was explored to investigate the effects on the nature of the molybdenum oxide films. X-ray diffraction (XRD) results showed that the films consisted of α-MoO 3 phase at deposition temperatures ranging from 400 to 560 o C (673-833 K). Crystalline α-MoO 3 films can be obtained from molybdenum dioxide acetylacetonate precursor, without need of a post-annealing treatment. The best crystalline quality was found in films having needle-like crystallites grown at deposition temperature of about 560 o C (833 K), which exhibit a strong (0 1 0) preferred orientation and a transparent visual appearance

  14. Preparation of molybdenum oxide thin films by MOCVD

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero, R. Martinez [Depto. de Ingenieria Metalurgica, ESIQIE-IPN, Mexico 07300, D.F. (Mexico); Garcia, J.R. Vargas [Depto. de Ingenieria Metalurgica, ESIQIE-IPN, Mexico 07300, D.F. (Mexico)]. E-mail: rvargasga@ipn.mx; Santes, V. [CIIEMAD-IPN, Miguel Othon de Mendizabal 485, Mexico 07700, D.F. (Mexico); Gomez, E. [Instituto de Quimica-UNAM, Circuito Exterior-Ciudad Universitaria, Mexico 04510, D.F. (Mexico)

    2007-05-31

    In this study, molybdenum oxide films were prepared in a horizontal hot-wall MOCVD apparatus using molybdenum dioxide acetylacetonate as precursor. The molybdenum precursor was synthesized from acetylacetone and molybdenum oxide powder. Thermal gravimetric (TG) and differential thermal analyses (DTA) of the precursor suggested the formation of molybdenum oxides around 430 {sup o}C (703 K). Thus, a range of deposition temperatures varying from 350 to 630 {sup o}C (623-903 K) was explored to investigate the effects on the nature of the molybdenum oxide films. X-ray diffraction (XRD) results showed that the films consisted of {alpha}-MoO{sub 3} phase at deposition temperatures ranging from 400 to 560 {sup o}C (673-833 K). Crystalline {alpha}-MoO{sub 3} films can be obtained from molybdenum dioxide acetylacetonate precursor, without need of a post-annealing treatment. The best crystalline quality was found in films having needle-like crystallites grown at deposition temperature of about 560 {sup o}C (833 K), which exhibit a strong (0 1 0) preferred orientation and a transparent visual appearance.

  15. Poly(vinyl Alcohol) Borate Gel Polymer Electrolytes Prepared by Electrodeposition and Their Application in Electrochemical Supercapacitors.

    Science.gov (United States)

    Jiang, Mengjin; Zhu, Jiadeng; Chen, Chen; Lu, Yao; Ge, Yeqian; Zhang, Xiangwu

    2016-02-10

    Gel polymer electrolytes (GPEs) have been studied for preparing flexible and compact electrochemical energy storage devices. However, the preparation and use of GPEs are complex, and most GPEs prepared through traditional methods do not have good wettability with the electrodes, which retard them from achieving their performance potential. In this study, these problems are addressed by conceiving and implementing a simple, but effective, method of electrodepositing poly(vinyl alcohol) potassium borate (PVAPB) GPEs directly onto the surfaces of active carbon electrodes for electrochemical supercapacitors. PVAPB GPEs serve as both the electrolyte and the separator in the assembled supercapacitors, and their scale and shape are determined solely by the geometry of the electrodes. PVAPB GPEs have good bonding to the active electrode materials, leading to excellent and stable electrochemical performance of the supercapacitors. The electrochemical performance of PVAPB GPEs and supercapacitors can be manipulated simply by adjusting the concentration of KCl salt used during the electrodeposition process. With a 0.9 M KCl concentration, the as-prepared supercapacitors deliver a specific capacitance of 65.9 F g(-1) at a current density of 0.1 A g(-1) and retain more than 95% capacitance after 2000 charge/discharge cycles at a current density of 1 A g(-1). These supercapacitors also exhibit intelligent high voltage self-protection function due to the electrolysis-induced cross-linking effect of PVAPB GPEs.

  16. Optimized sample preparation for two-dimensional gel electrophoresis of soluble proteins from chicken bursa of Fabricius

    Directory of Open Access Journals (Sweden)

    Zheng Xiaojuan

    2009-10-01

    Full Text Available Abstract Background Two-dimensional gel electrophoresis (2-DE is a powerful method to study protein expression and function in living organisms and diseases. This technique, however, has not been applied to avian bursa of Fabricius (BF, a central immune organ. Here, optimized 2-DE sample preparation methodologies were constructed for the chicken BF tissue. Using the optimized protocol, we performed further 2-DE analysis on a soluble protein extract from the BF of chickens infected with virulent avibirnavirus. To demonstrate the quality of the extracted proteins, several differentially expressed protein spots selected were cut from 2-DE gels and identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS. Results An extraction buffer containing 7 M urea, 2 M thiourea, 2% (w/v 3-[(3-cholamidopropyl-dimethylammonio]-1-propanesulfonate (CHAPS, 50 mM dithiothreitol (DTT, 0.2% Bio-Lyte 3/10, 1 mM phenylmethylsulfonyl fluoride (PMSF, 20 U/ml Deoxyribonuclease I (DNase I, and 0.25 mg/ml Ribonuclease A (RNase A, combined with sonication and vortex, yielded the best 2-DE data. Relative to non-frozen immobilized pH gradient (IPG strips, frozen IPG strips did not result in significant changes in the 2-DE patterns after isoelectric focusing (IEF. When the optimized protocol was used to analyze the spleen and thymus, as well as avibirnavirus-infected bursa, high quality 2-DE protein expression profiles were obtained. 2-DE maps of BF of chickens infected with virulent avibirnavirus were visibly different and many differentially expressed proteins were found. Conclusion These results showed that method C, in concert extraction buffer IV, was the most favorable for preparing samples for IEF and subsequent protein separation and yielded the best quality 2-DE patterns. The optimized protocol is a useful sample preparation method for comparative proteomics analysis of chicken BF tissues.

  17. Preparation of mixed oxides (Th,U)O2: an evaluation of different techniques

    International Nuclear Information System (INIS)

    Ayoub, Jamil Mahmoud Said

    1999-01-01

    An evaluation of different ways of obtaining (Th-U)O 2 mixed oxides is described. Coprecipitation, mechanical mixing of uranium and thorium powders, and the sol-gel technique were studied in order to get a large spectrum of knowledge of the process performance. The use of ultrasonic waves for the homogenization of the hydroxide mixture and microwave heating for powder drying was also investigated. Sol-gel showed the best results regarding the specific area for obtained samples. Oxide drying by microwave is an effective method to get mixed oxides for fuel fabrication. Neither coprecipitation nor mechanical mixing of the thorium and uranium oxide powders is suitable for the purpose. The obtained data are less than 70% than those achieved when sol-gel process is performed. Electronic microscopy, X-ray fluorescence and diffraction, thermogravimetry, specific gravidity and specific area determination (BET) used for sample characterization were convenient and accomplished good results. (author)

  18. Effect of Preparation Methods on Al2O3 Supported CuO-CeO2-ZrO2 Catalysts for CO Oxidation

    Directory of Open Access Journals (Sweden)

    Gaurav Rattan

    2012-12-01

    Full Text Available To examine the effect of preparation methods, four catalyst samples having same composition (CuCe5.17Zr3.83Ox/g-Al2O3 (15wt% were prepared by four different methods for CO oxidation. The catalysts were prepared by co-impregnation, citric acid sol-gel, urea nitrate combustion and urea gelation co-precipitation methods, and characterized by BET, XRD, TGA/DSC and SEM. The The air oxidation of CO was carried out in a tubular fixed bed reactor under the following operating conditions: catalyst weight - 100 mg, temperature - ambient to 250 oC, pressure - atmospheric, 2.5% CO in air, total feed rate - 60 ml/min.  It was observed that the catalytic activity greatly influenced by the preparation methods. The highest activity of the catalyst prepared by the sol gel method appeared to be associated with its largest BET surface area. All the four catalysts were active for CO oxidation and did not show deactivation of catalytic activity for 50 hours of continuous runs. The ranking order of the preparation methods of the catalyst is as follows: sol-gel > co-impregnation > urea gelation > urea nitrate combustion. Copyright © 2012 by BCREC UNDIP. All rights reservedReceived: 14th June 2012, Revised: 8th September 2012, Accepted: 19th September 2012[How to Cite: G. Rattan, R. Prasad, R.C.Katyal. (2012. Effect of Preparation Methods on Al2O3 Supported CuO-CeO2-ZrO2 Catalysts for CO Oxidation. Bulletin of Chemical Reaction Engineering & Catalysis, 7(2: 112-123. doi:10.9767/bcrec.7.2.3646.112-123] [How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.2.3646.112-123 ] | View in 

  19. Production of Monodisperse Cerium Oxide Microspheres with Diameters near 100 µm by Internal Gelation Sol-Gel Methods

    Energy Technology Data Exchange (ETDEWEB)

    Katalenich, Jeffrey A.; Kitchen, Brian B.; Pierson, Bruce

    2018-05-01

    Internal gelation sol-gel methods have used a variety of sphere forming methods in the past to produce metal oxide microspheres, but typically with poor control over the size uniformity at diameters near 100 µm. This work describes efforts to make and measure internal gelation, sol-gel microspheres with very uniform diameters in the 100 – 200 µm size range using a two-fluid nozzle. A custom apparatus was used to form aqueous droplets of sol-gel feed solutions in silicone oil and heat them to cause gelation of the spheres. Gelled spheres were washed, dried, and sintered prior to mounting on glass slides for optical imaging and analysis. Microsphere diameters and shape factors were determined as a function of silicone oil flow rate in a two-fluid nozzle and the size of a needle dispensing the aqueous sol-gel solution. Nine batches of microspheres were analyzed and had diameters ranging from 65.5 ± 2.4 µm for the smallest needle and fastest silicone oil flow rate to 211 ± 4.7 µm for the largest needle and slowest silicone oil flow rate. Standard deviations for measured diameters were less than 8% for all samples and most were less than 4%. Microspheres had excellent circularity with measured shape factors of 0.9 – 1. However, processing of optical images was complicated by shadow effects in the photoresist layer on glass slides and by overlapping microspheres. Based on calculated flow parameters, microspheres were produced in a simple dripping mode in the two-fluid nozzle. Using flow rates consistent with a simple dripping mode in a two-fluid nozzle configuration allows for very uniform oxide microspheres to be produced using the internal-gelation sol-gel method.

  20. A preparation method of thorium nitrides and their oxidation behavior

    International Nuclear Information System (INIS)

    Miyake, M.; Katsura, M.; Uno, M.

    1991-01-01

    In the preparation of ThN, thermal decomposition of Th 3 N 4 has been performed under various conditions and the kind of products has been examined as a function of temperature and time. In the Th-N-O system there exist ThN, Th 3 N 4 , ThO 2 , and Th 2 N 2 O as solid phases. The thermodynamic stability of these solid compounds has been evaluated as a function of P(O 2 ) and P(N 2 ) and compared with the experimental results. One of the main aims in this work is to explore the oxidation behaviour of thorium nitrides. Preliminary oxidation experiments of ThN and Th 3 N 4 gave the same result. From the study of the air oxidation of Th 3 N 4 , it was found that the oxidation product obtained close to room temperature exhibited only one or more diffuse reflections in its diffraction pattern, suggesting that the product may be of a poor crystalline nature. In order to reveal the dependence of the crystallinity of the product on the oxidation temperature, powdered Th 3 N 4 was exposed to air for one week at 0, 50, and 100degC and the product was examined by X-ray diffraction. In order to prepare ThO 2 with a wide variety of degrees of crystallinity, poorly-crystallized ThO 2 , which is produced by the air oxidation of Th 3 N 4 at 50degC, was heat-treated at temperatures ranging from 200 to 1,400degC in air and vacuum. The degree of crystallinity of ThO 2 heat-treated at and below 1000degC is discussed in terms of the number of detected peaks in the X-ray diffraction patterns, and above 1100degC in terms of the Kα doublet resolution of detected peaks. (author). 11 refs., 7 figs., 6 tabs

  1. Use of hydroxyapatite prepared by sol-gel method for gamma ray and electron beam dosimetry

    International Nuclear Information System (INIS)

    Hajiloo, N.; Ziaie, F.; Hesami, M.

    2011-01-01

    In this research, radiation dosimetry was made through measuring free radicals induced in synthetic hydroxyapatite using EPR spectroscopy. At the first step, the hydroxyapatite nano-powders were synthesized via sol-gel method. The produced powders were passed through a thermal treatment, weighted and packed. Then, the samples were irradiated at different dose rates using 60 Co γ-ray and 10 MeV electron beam radiation at a high dose range. The hydroxyapatite signal intensity of hydroxyapatite samples were measured at room temperature in the air. Subsequently, the variations of the EPR signal intensities were constructed as peak-to-peak signal amplitude and were compared with alanine and bone powder samples. The results showed that the EPR signal intensity of the hydroxyapatite samples are several times higher than alanine and bone powder and are saturated at the higher dose rates in comparison with other species.

  2. The effect of Ni and Fe doping on YBCO powder prepared by sol gel method

    Directory of Open Access Journals (Sweden)

    F Saeb

    2009-08-01

    Full Text Available  We fabricated YBa2Cu3-xMxO7- d (M=Ni, Fe bulk samples, with stochiometric amount 0≤x≤0.045 by sol-gel method. The phase analysis and microstructure of specimens were examined by XRD and SEM. The electrical resistivity was measured using standard four probe technique for 77-300K. Investigation of XRD spectrum by MAUD shows Ni and Fe ions substitute in Cu(2 and Cu(1 site, respectively. Transition temperature decreases in 93-87K for Ni-doped samples and 93-92K for Fe-doped series. It seems that the suppression of superconductivity has no direct correlation with the magnetism of ions itself .

  3. Synthesis and Characterization of Nanostructure Tio2/Anthraquenone (AQ Prepared by Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    Fadhela M. Hussein

    2017-11-01

    Full Text Available sol–gel technique conducted to synthesize nano titanium dioxide with anthraquenone (AQ relatively in acidic pH. Nanoparticles were characterized using techniques like, Scanning Electrion Microscope (SEM, Atomic Force Microscope (AFM, UV-Visible Spectrioscopy, X-ray diffraction (XRD, Fourier transform infrared (FT-IR, SEM picture display that the TiO2/AQ is spherical in style, the band gap of TiO2/AQ nanoparticle is (3.05eV, BET and BJH analysis provides Pore volume and specific Surface area and the kinetic studie Suggest that the reaction is pseudo first order and the rate of reaction was reduce with rising initial concentration for p-Nitrotolune.

  4. Sol-gel process for thermal reactor fuel fabrication

    International Nuclear Information System (INIS)

    Mukerjee, S.K.

    2008-01-01

    Full text: Sol-gel processes have revolutionized conventional ceramic technology by providing extremely fine and uniform powders for the fabrication of ceramics. The use of this technology for nuclear fuel fabrication has also been explored in many countries. Unlike the conventional sol-gel process, sol-gel process for nuclear fuels tries to eliminate the preparation of powders in view of the toxic nature of the powders particularly those of plutonium and 233 U. The elimination of powder handling thus makes this process more readily amenable for use in glove boxes or for remote handling. In this process, the first step is the preparation of microspheres of the fuel material from a solution which is then followed by vibro-compaction of these microspheres of different sizes to obtain the required smear density of fuel inside a pin. The maximum achievable packing density of 92 % makes it suitable for fast reactors only. With a view to extend the applicability of sol-gel process for thermal reactor fuel fabrication the concept of converting the gel microspheres derived from sol-gel process, to the pellets, has been under investigation for several years. The unique feature of this process is that it combines the advantages of sol-gel process for the preparation of fuel oxide gel microspheres of reproducible quality with proven irradiation behavior of the pellet fuel. One of the important pre-requisite for the success of this process is the preparation of soft oxide gel microspheres suitable for conversion to dense pellets free from berry structure. Studies on the internal gelation process, one of the many variants of sol-gel process, for obtaining soft oxide gel microspheres suitable for gel pelletisation is now under investigation at BARC. Some of the recent findings related to Sol-Gel Microsphere Pelletisation (SGMP) in urania-plutonia and thoria-urania systems will be presented

  5. Hyaluronic acid gel (Juvéderm™ preparations in the treatment of facial wrinkles and folds

    Directory of Open Access Journals (Sweden)

    Inja Bogdan Allemann

    2008-12-01

    Full Text Available Inja Bogdan Allemann, Leslie BaumannUniversity of Miami Cosmetic Group, Leonard M. Miller School of Medicine, Miami Heart Institute, Miami Beach, Florida, USAAbstract: Soft tissue augmentation with temporary dermal fillers is a continuously growing field, supported by the ongoing development and advances in technology and biocompatibility of the products marketed. The longer lasting, less immunogenic and thus more convenient hyaluronic acid (HA fillers are encompassing by far the biggest share of the temporary dermal filler market. Since the approval of the first HA filler, Restylane®, there are at least 10 HA fillers that have been approved by the FDA. Not all of the approved HA fillers are available on the market, and many more are coming. The Juvéderm™ product line (Allergan, Irvine, CA, consisting of Juvéderm™ Plus and Juvéderm™ Ultra Plus, was approved by the FDA in 2006. Juvéderm™ is a bacterium-derived nonanimal stabilized HA. Juvéderm™ Ultra and Ultra Plus are smooth, malleable gels with a homologous consistency that use a new technology called “Hylacross™ technology”. They have a high concentration of cross-linked HAs, which accounts for its longevity. Juvéderm™ Ultra Plus is used for volumizing and correcting deeper folds, whereas Juvéderm™ Ultra is best for contouring and volumizing medium depth facial wrinkles and lip augmentation. Various studies have shown the superiority of the HA filler products compared with collagen fillers for duration, volume needed, and patient satisfaction. Restylane®, Perlane®, and Juvéderm™ are currently the most popular dermal fillers used in the United States.Keywords: hyaluronic acid gel, Juvéderm™, facial wrinkles, facial folds

  6. Blade-coated sol-gel indium-gallium-zinc-oxide for inverted polymer solar cell

    Directory of Open Access Journals (Sweden)

    Yan-Huei Lee

    2016-11-01

    Full Text Available The inverted organic solar cell was fabricated by using sol-gel indium-gallium-zinc-oxide (IGZO as the electron-transport layer. The IGZO precursor solution was deposited by blade coating with simultaneous substrate heating at 120 °C from the bottom and hot wind from above. Uniform IGZO film of around 30 nm was formed after annealing at 400 °C. Using the blend of low band-gap polymer poly[(4,8-bis-(2-ethylhexyloxy-benzo(1,2-b:4,5-b’dithiophene-2,6-diyl-alt- (4-(2-ethylhexanoyl-thieno [3,4-b]thiophene--2-6-diyl] (PBDTTT-C-T and [6,6]-Phenyl C71 butyric acid methyl ester ([70]PCBM as the active layer for the inverted organic solar cell, an efficiency of 6.2% was achieved with a blade speed of 180 mm/s for the IGZO. The efficiency of the inverted organic solar cells was found to depend on the coating speed of the IGZO films, which was attributed to the change in the concentration of surface OH groups. Compared to organic solar cells of conventional structure using PBDTTT-C-T: [70]PCBM as active layer, the inverted organic solar cells showed significant improvement in thermal stability. In addition, the chemical composition, as well as the work function of the IGZO film at the surface and inside can be tuned by the blade speed, which may find applications in other areas like thin-film transistors.

  7. Catalytic Oxidation of Toluene on Hydrothermally Prepared Ceria Nanocrystals

    Directory of Open Access Journals (Sweden)

    M. Duplančić

    2018-01-01

    Full Text Available Ceria nanocrystals were prepared hydrothermally and tested as potential catalysts for oxidation of volatile organic compounds using toluene as a model compound. Pure ceria with a crystallite size of 4 nm, determined by the Scherrer method from XRD pattern has been obtained. The specific surface area of the prepared nanoparticles determined by BET analysis yielded 201 m2 g–1, while the band gap of 3.2 eV was estimated from DRS spectrum via Tauc’s plot. Catalytic tests were performed on calcined ceria (500 °C with increased crystallite size (9 nm caused by thermal treatment. The tests showed good activities for the toluene oxidation with T50 temperatures, corresponding to 50 % toluene conversion, observed at 250 °C and even lower temperatures depending on the total flow rate of the gas mixture. The one-dimensional pseudo-homogeneous model of the fixed bed reactor was proposed to describe the reactor performance and the appropriate kinetic parameters were estimated. Good agreement between experimental data and the proposed model was observed.

  8. Preparation and evaluation of a phospholipid-based injectable gel for the long term delivery of leuprolide acetaterrh.

    Science.gov (United States)

    Long, Danhong; Gong, Tao; Zhang, Zhirong; Ding, Rui; Fu, Yao

    2016-07-01

    A phospholipid-based injectable gel was developed for the sustained delivery of leuprolide acetate (LA). The gel system was prepared using biocompatible materials (SPME), including soya phosphatidyl choline (SPC), medium chain triglyceride (MCT) and ethanol. The system displayed a sol state with low viscosity in vitro and underwent in situ gelation in vivo after subcutaneous injection. An in vitro release study was performed using a dialysis setup with different release media containing different percentages of ethanol. The stability of LA in the SPME system was investigated under different temperatures and in the presence of various antioxidants. In vivo studies in male rats were performed to elucidate the pharmacokinetic profiles and pharmacodynamic efficacy. A sustained release of LA for 28 days was observed without obvious initial burst in vivo. The pharmacodynamic study showed that once-a-month injection of LA-loaded SPME (SPME-LA) led to comparable suppression effects on the serum testosterone level as observed in LA solution except for the onset time. These findings demonstrate excellent potential for this novel SPME system as a sustained release delivery system for LA.

  9. Preparation and evaluation of a phospholipid-based injectable gel for the long term delivery of leuprolide acetaterrh

    Directory of Open Access Journals (Sweden)

    Danhong Long

    2016-07-01

    Full Text Available A phospholipid-based injectable gel was developed for the sustained delivery of leuprolide acetate (LA. The gel system was prepared using biocompatible materials (SPME, including soya phosphatidyl choline (SPC, medium chain triglyceride (MCT and ethanol. The system displayed a sol state with low viscosity in vitro and underwent in situ gelation in vivo after subcutaneous injection. An in vitro release study was performed using a dialysis setup with different release media containing different percentages of ethanol. The stability of LA in the SPME system was investigated under different temperatures and in the presence of various antioxidants. In vivo studies in male rats were performed to elucidate the pharmacokinetic profiles and pharmacodynamic efficacy. A sustained release of LA for 28 days was observed without obvious initial burst in vivo. The pharmacodynamic study showed that once-a-month injection of LA-loaded SPME (SPME-LA led to comparable suppression effects on the serum testosterone level as observed in LA solution except for the onset time. These findings demonstrate excellent potential for this novel SPME system as a sustained release delivery system for LA.

  10. Epitaxial growth of Er, Ti doped LiNbO3 films prepared by sol-gel method

    International Nuclear Information System (INIS)

    Takahashi, Makoto; Yoshiga, Tsuyoshi; Kajitani, Naofumi; Takeda, Yuki; Sato, Shoji; Wakita, Koichi; Ohnishi, Naoyuki; Hotta, Kazutoshi; Kurachi, Masato

    2006-01-01

    Erbium (Er 3+ ) doped lithium niobate (LiNbO 3 ) thick films were deposited on z-cut congruent LiNbO 3 (LN) substrate by the sol-gel method from the 0.20 mol/dm 3 precursor solution containing various Er 3+ concentration and 0.10 mol/dm 3 poly(vinyl alcohol) (PVA), and their crystal characteristics were evaluated. The Er 3+ concentration in the LN film was controlled by the Er 3+ concentration in the starting solution. The orientation relationships between Er doped LN films and substrates were determined by X-ray diffraction, Raman spectroscopy, and transmission electron microscopy, and (006) oriented Er doped LN epitaxial layers with parallel epitaxial relationships could be grown on the z-cut LN wafer. Moreover, it was made clear from the electron beam diffraction measurements that the film came to be polycrystalline, when the Er concentration was over 3 mol%. The refractive index of Er-doped LN films decreased with increasing Er concentration. 1.5 mol% Ti: 1.0 mol% Er LN films, which acted as a waveguide, were prepared by our so-gel method. It showed the 1530 nm emission by 980 nm excitation, which was considered to be due to the Er 3+ corresponding to the 4 I 13/2 → 4 I 15/2 transition. (author)

  11. Preparation and Scintillating Properties of Sol-Gel Eu3+, Tb3+ Co-Doped Lu2O3 Nanopowders

    Directory of Open Access Journals (Sweden)

    Joel Moreno Palmerin

    2011-09-01

    Full Text Available Nanocrystalline Eu3+, Tb3+ co-doped Lu2O3 powders with a maximum size of 25.5 nm were prepared by the sol-gel process, using lutetium, europium and terbium nitrates as precursors, and ethanol as a solvent. Differential thermal analysis (DTA and infrared spectroscopy (IR were used to study the chemical changes during the xerogel annealing. After the sol evaporation at 100 °C, the formed gel was annealed from 300 to 900 °C for 30 min under a rich O2 atmosphere, and the yielded product was analyzed by X-ray diffraction (XRD to characterize the microstructural behavior and confirm the crystalline structure. The results showed that Lu2O3 nanopowders start to crystallize at 400 °C and that the crystallite size increases along with the annealing temperature. A transmission electron microscopy (TEM study of samples annealed at 700 and 900 °C was carried out in order to analyze the microstructure, as well as the size, of crystallites. Finally, in regard to scintillating properties, Eu3+ dopant (5 mol%, Tb3+ codoped Lu2O3 exhibited a typical red emission at 611 nm (Do→7F2, furthermore, the effect of Tb3+ molar content (0.01, 0.015 and 0.02% mol on the Eu3+ radioluminiscence was analyzed and it was found that the higher emission intensity corresponds to the lower Tb3+ content.

  12. Preparation and characterization of quercetin-loaded silica microspheres stabilized by combined multiple emulsion and sol-gel processes

    Directory of Open Access Journals (Sweden)

    Kim Young Ho

    2015-01-01

    Full Text Available Despite exhibiting a wide spectrum of cosmeceutical properties, flavonoids and related compounds have some limitations related to their stability and solubility in distilledwater. In this project, we prepared silica microspheres using a novel method that uses polyol-in-oil-in-water (P/O/W emulsion and sol-gel methods as techniques for stabilizing quercetin. A stable microsphere suspension was successfully preparedusing a mixed solvent system comprising a polyol-phase medium for performing the sol-gel processing of tetraethyl orthosilicate (TEOS as an inorganic precursor with outer water phase. The morphology of the microsphere was evaluated using a scanning electron microscope (SEM, which showed a characteristic spherical particle shape with a smooth surface. Furthermore, SEM/EDSanalysis of a representative microsphere demonstrated that the inner structure of the silica microspheres was filled with quercetin. The mean diameter of the microsphere was in the range 20.6-35.0 μm, and the encapsulation efficiency ranged from 17.8% to 27.5%. The free and encapsulated quercetin samples were incubated in separateaqueous solutions at 25 and 42°C for 28 days. The residualcontent of the quercetin encapsulated by silica microspheres was 82% at 42°C. In contrast, that of the free quercetin stored at 42°C decreased to ~24%.

  13. Preparation and characterization of composites of ultrasonic gel and copper sulphate for using as magnetic resonance body simulator

    International Nuclear Information System (INIS)

    Cardoso, Gabriela P.; Soares, Sidney S.; Gontijo, Rodrigo M.G.; Batista, Adriana S.M.; Pereira, Esther Lorrayne M.

    2017-01-01

    The use of magnetic resonance (MRI) body simulators has application in both equipment control and didactics, providing training to new professionals, regarding the manipulation of parameters related to image weights. For this, it is necessary to simulate longitudinal (T1) and transverse (T2) relaxation times in order to control the extrinsic echo time (TE) and repetition time (TR) parameters in obtaining images with different contrasts. For this purpose, composites with different proportions of ultrasonic gel and copper sulphate were prepared for submission to MRI for the characterization of the times T1 and T2. The selection of copper sulphate, paramagnetic material, was conducted considering relaxation times similar to the different body tissues in order to reproduce images of suitable contrasts. Copper sulphate powder was characterized by the X-Ray Diffraction (XRD) technique which showed characteristic peaks of copper and sulfate group. The composite was evaluated using Fourier Transform Infrared Spectrometry (FTIR) and Visible Ultraviolet Spectrometry (UV-Vis) techniques, demonstrating composite stability for future imaging tests. In the UV-Vis analyzes the peak centered at 725 nm was monitored by the overlap of the peaks at wavelengths between 200 - 450 nm, gel and copper. FTIR of the copper sulphate powder was used for comparison with composite spectrum

  14. Preparation and spectroscopic analysis of zinc oxide nanorod thin films of different thicknesses

    Directory of Open Access Journals (Sweden)

    Mia Nasrul Haque

    2017-10-01

    Full Text Available Zinc oxide thin films with different thicknesses were prepared on microscopic glass slides by sol-gel spin coating method, then hydrothermal process was applied to produce zinc oxide nanorod arrays. The nanorod thin films were characterized by various spectroscopic methods of analysis. From the images of field emission scanning electron microscope (FESEM, it was observed that for the film thickness up to 200 nm the formed nanorods with wurtzite hexagonal structure were uniformly distributed over the entire surface substrate. From X-ray diffraction analysis it was revealed that the thin films had good polycrystalline nature with highly preferred c-axis orientation along (0 0 2 plane. The optical characterization done by UV-Vis spectrometer showed that all the films had high transparency of 83 % to 96 % in the visible region and sharp cut off at ultraviolet region of electromagnetic spectrum. The band gap of the films decreased as their thickness increased. Energy dispersive X-ray spectroscopy (EDS showed the presence of zinc and oxygen elements in the films and Fourier transform infrared spectroscopy (FT-IR revealed the chemical composition of ZnO in the film.

  15. Preparation and characterization of Ce/Zr mixed oxides and their use as catalysts for the direct oxidation of dry CH{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Larrondo, Susana; Vidal, Maria Adelina; Irigoyen, Beatriz; Amadeo, Norma [Lab. de Procesos Cataliticos, Depto. de Ing. Quimica, Facultad de Ingenieria, University de Buenos Aires, Pab. de Industrias, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Craievich, Aldo F. [Instituto de Fisica, USP, Travessa R da Rua do Matao, no.187, Cidade Universitaria, 05508-900, Sao Paulo, SP (Brazil); Lamas, Diego G.; Fabregas, Ismael O.; Lascalea, Gustavo E.; Reca, Noemi E. Walsoee de [Centro de Investigaciones en Solidos CINSO, CITEFA-CONICET, J.B. de La Salle 4397, 1603 Villa Martelli, Buenos Aires (Argentina)

    2005-10-30

    Solid oxide fuel cells have a promissory future in the direct combustion of fuels but, their main drawbacks are the high operation temperature and the rapid performance degradation due to carbon deposition in the anode. The development of ceria-based anodes with good electronic conductivity at lower temperatures seems to be a promising way to solve those problems. In this work, preparation of compositionally homogeneous Ce/Zr oxides by a gel-combustion process and their characterization are reported. A detailed crystallographic study performed by synchrotron radiation X-ray diffraction has been carried out, in order to analyze the correlation between crystal structure and catalytic properties. The oxides presented specific area values, porous size distribution and carbon content values desirable for solid catalysts. Likewise, increasing the content of ZrO{sub 2} facilitates the reducibility of both surface and bulk sites in the solid. The oxides have been active in the combustion of methane. Their performances were stable during a typical work period of 8h, with no evidence of formation of carbonaceous deposits. The experiments that were carried out confirm the promising features of these oxides as anodic materials in solid oxide fuel cells.

  16. Novel metal oxides prepared by ingenious synthetic routes

    International Nuclear Information System (INIS)

    Rao, C.N.R.; Gopalakrishnan, J.; Vidyasagar, K.; Ganguli, A.K.; Ramanan, A.; Ganapathi, L.

    1986-01-01

    Several novel oxides have been prepared by the decomposition of carbonate precursors of calcite structure of the general formulas Mn/sub 1-x/M/sub x/CO 3 (M = Mg,Co,Cd), Ca/sub 1-x/M/sup prime//sub x/CO 3 , and Ca/sub 1-x/-yM/sup //sub x/M/sup double-prime//sub y/CO 3 (M',M'' = Mn,Fe,Co). Typical of the oxides synthesized are a variety of monoxides, Mn/sub 1-x/M/sub x/O, of rocksalt structure and perovskite-related oxides such as Ca 2 FeCoO 5 , Ca 2 Co 2 O 5 , and Ca 3 Fe 2 MnO 8 , many of them exhibiting novel anion-vacancy-ordered superstructures. An interesting series of oxides prepared by the topotactic reduction of Ca 2 Fe/sub 2-x/Mn/sub x/O/sub 6-y/ (synthesized by the decomposition of the corresponding carbonate precursors) is Ca 2 Fe/sub 2-x/Mn/sub x/O 5 where three different coordination polyhedra (octahedra, tetrahedra, and square pyramids) of the transition metals coexist. Topotactic reduction of LaCoO 3 and LaNiO 3 yields new oxides, La 2 Co 2 O 5 and La 2 Ni 2 O 5 , possessing anion-vacancy-ordered superstructures. While La 2 Co 2 O 5 adopts the brownmillerite structure, La 2 Ni 2 O 5 exhibits a new type of vacancy ordering with octahedral and square-planar coordination of Ni 2+ . Slightly reduced LaNiO 3 seem to exhibit crystallographic shear (CS) planes similar to WO/sub 3-x/. Topotactic dehydration of isostructural Mo/sub 1-x/W/sub x/O 3 x H 2 O provides a convenient route for the synthesis of Mo/sub 1-x/W/sub x/O 3 (0 3 -related structure

  17. Facile preparation of superhydrophobic surfaces based on metal oxide nanoparticles

    Science.gov (United States)

    Bao, Xue-Mei; Cui, Jin-Feng; Sun, Han-Xue; Liang, Wei-Dong; Zhu, Zhao-Qi; An, Jin; Yang, Bao-Ping; La, Pei-Qing; Li, An

    2014-06-01

    A novel method for fabrication of superhydrophobic surfaces was developed by facile coating various metal oxide nanoparticles, including ZnO, Al2O3 and Fe3O4, on various substrates followed by treatment with polydimethylsiloxane (PDMS) via chemical vapor deposition (CVD) method. Using ZnO nanoparticles as a model, the changes in the surface chemical composition and crystalline structures of the metal oxide nanoparticles by PDMS treatment were investigated by X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and Fourier transform infrared (FTIR) analysis. The results show that the combination of the improved surface roughness generated from of the nanoparticles aggregation with the low surface-energy of silicon-coating originated from the thermal pyrolysis of PDMS would be responsible for the surface superhydrophobicity. By a simple dip-coating method, we show that the metal oxide nanoparticles can be easily coated onto the surfaces of various textural and dimensional substrates, including glass slide, paper, fabric or sponge, for preparation of superhydrophobic surfaces for different purpose. The present strategy may provide an inexpensive and new route to surperhydrophobic surfaces, which would be of technological significance for various practical applications especially for separation of oils or organic contaminates from water.

  18. Facile preparation of superhydrophobic surfaces based on metal oxide nanoparticles

    International Nuclear Information System (INIS)

    Bao, Xue-Mei; Cui, Jin-Feng; Sun, Han-Xue; Liang, Wei-Dong; Zhu, Zhao-Qi; An, Jin; Yang, Bao-Ping; La, Pei-Qing; Li, An

    2014-01-01

    A novel method for fabrication of superhydrophobic surfaces was developed by facile coating various metal oxide nanoparticles, including ZnO, Al 2 O 3 and Fe 3 O 4 , on various substrates followed by treatment with polydimethylsiloxane (PDMS) via chemical vapor deposition (CVD) method. Using ZnO nanoparticles as a model, the changes in the surface chemical composition and crystalline structures of the metal oxide nanoparticles by PDMS treatment were investigated by X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and Fourier transform infrared (FTIR) analysis. The results show that the combination of the improved surface roughness generated from of the nanoparticles aggregation with the low surface-energy of silicon-coating originated from the thermal pyrolysis of PDMS would be responsible for the surface superhydrophobicity. By a simple dip-coating method, we show that the metal oxide nanoparticles can be easily coated onto the surfaces of various textural and dimensional substrates, including glass slide, paper, fabric or sponge, for preparation of superhydrophobic surfaces for different purpose. The present strategy may provide an inexpensive and new route to surperhydrophobic surfaces, which would be of technological significance for various practical applications especially for separation of oils or organic contaminates from water.

  19. Facile preparation of superhydrophobic surfaces based on metal oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Xue-Mei; Cui, Jin-Feng; Sun, Han-Xue; Liang, Wei-Dong; Zhu, Zhao-Qi; An, Jin; Yang, Bao-Ping; La, Pei-Qing; Li, An, E-mail: lian2010@lut.cn

    2014-06-01

    A novel method for fabrication of superhydrophobic surfaces was developed by facile coating various metal oxide nanoparticles, including ZnO, Al{sub 2}O{sub 3} and Fe{sub 3}O{sub 4}, on various substrates followed by treatment with polydimethylsiloxane (PDMS) via chemical vapor deposition (CVD) method. Using ZnO nanoparticles as a model, the changes in the surface chemical composition and crystalline structures of the metal oxide nanoparticles by PDMS treatment were investigated by X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and Fourier transform infrared (FTIR) analysis. The results show that the combination of the improved surface roughness generated from of the nanoparticles aggregation with the low surface-energy of silicon-coating originated from the thermal pyrolysis of PDMS would be responsible for the surface superhydrophobicity. By a simple dip-coating method, we show that the metal oxide nanoparticles can be easily coated onto the surfaces of various textural and dimensional substrates, including glass slide, paper, fabric or sponge, for preparation of superhydrophobic surfaces for different purpose. The present strategy may provide an inexpensive and new route to surperhydrophobic surfaces, which would be of technological significance for various practical applications especially for separation of oils or organic contaminates from water.

  20. Preparation of cerium oxide for lens polishing powder

    International Nuclear Information System (INIS)

    Injarean, Uthaiwan; Rodthongkom, Chouvana; Pichestapong, Pipat; Changkrurng, Kalaya

    2003-10-01

    Cerium is an element of rare earth group which is called lanthanide series. It is found in the ores like monazite and xenotime which are the tailings of tin mines in the south of Thailand. Cerium is used mostly as lens polishing powder besides the applications in other industries. In this study, cerium extracted from monazite ore breakdown by alkaline process was used for the preparation of lens polishing powder. Cerium hydroxide cake from the process was dissolved by hydrochloric acid and precipitated with oxalic acid. The oxalate precipitate then was calcined to oxide powder and its particle size was measured. Precipitation conditions being studied are concentration of feed cerium chloride solution, concentration of oxalic acid used for the precipitation, concentration of sulfuric acid used as precipitation control reagent and the precipitation temperature. It was found that the appropriate precipitation conditions yielded the fine oxide powder with particle size about 12μm. The oxide powder can be ground to the size of 1-3 μm which is suitable for making lens polishing powder

  1. High Refractive Organic–Inorganic Hybrid Films Prepared by Low Water Sol-Gel and UV-Irradiation Processes

    Directory of Open Access Journals (Sweden)

    Hsiao-Yuan Ma

    2016-03-01

    Full Text Available Organic-inorganic hybrid sols (Ti–O–Si precursor were first synthesized by the sol-gel method at low addition of water, and were then employed to prepare a highly refractive hybrid optical film. This film was obtained by blending the Ti–O–Si precursor with 2-phenylphenoxyethyl acrylate (OPPEA to perform photo-polymerization by ultraviolet (UV irradiation. Results show that the film transparency of poly(Ti–O–Si precursor-co-OPPEA film is higher than that of a pure poly(Ti–O–Si precursor film, and that this poly(Ti–O–Si precursor-co-OPPEA hybrid film exhibits a high transparency of ~93.7% coupled with a high refractive index (n of 1.83 corresponding to a thickness of 2.59 μm.

  2. Visible Light-Photocatalytic Activity of Sulfate-Doped Titanium Dioxide Prepared by the Sol−Gel Method

    Directory of Open Access Journals (Sweden)

    Tsuneo Fujii

    2013-04-01

    Full Text Available Sulfate-doped TiO2 was prepared from sol−gel systems containing titaniumalkoxide and sulfuric acid. The time needed for gelation of the systems was significantlyreduced by ultrasonic irradiation. The doped sulfate was observed by FTIR and XPSmeasurements. Some sulfate ions remained in the TiO2 even after heating at 300−600 °C.The UV and visible photocatalytic activities of the samples were confirmed by thedegradation of trichloroethylene (TCE. The activity of the photocatalyst samples duringthe UV irradiation strongly depended on their crystallinities rather than their specificsurface areas, i.e., adsorption ability. The degradation rate during the visible irradiationdepended on both the adsorption ability and visible absorption of the photocatalystsamples. The visible absorption induced by the sulfate-doping was effective for theTCE degradation.

  3. Recovery of Silver Using Adsorption Gels Prepared from Microalgal Residue Immobilized with Functional Groups Containing Sulfur or Nitrogen

    Directory of Open Access Journals (Sweden)

    Kanjana Khunathai

    2017-06-01

    Full Text Available Although biodiesel oil extracted from microalgae attracts much attention as one of the most promising green energies, its high production cost is a big problem, impeding its extensive use. In order to lower the production cost, the effective use of microalgal residue after extracting biofuel was investigated as a feed material of functional materials. In the present work, a new adsorbent for silver(I was prepared by immobilizing functional groups of polyethylene-polyamine or dithiooxamide, which exhibita high affinity for soft Lewis acids such as silver(I ions. Their adsorption behaviors for silver(I were investigated from aqueous nitrate and acidothiourea media. The effects of the concentrations of nitrate and thiourea, as well as of sulfuric acid, were qualitatively interpreted. From the study of adsorption isotherms on these gels, they were found to exhibita higher adsorption capacity than the majority of those reported to date.

  4. Sol-gel processed thin-layer ruthenium oxide/carbon black supercapacitors: A revelation of the energy storage issues

    Energy Technology Data Exchange (ETDEWEB)

    Panic, V.V.; Dekanski, A.B.; Stevanovic, R.M. [Institute of Chemistry, Technology and Metallurgy, Department of Electrochemistry, University of Belgrade, Njegoseva 12, Belgrade 125213 (RS)

    2010-07-01

    Hydrous ruthenium oxide/carbon black nanocomposites were prepared by impregnation of the carbon blacks by differently aged inorganic RuO{sub 2} sols, i.e. of different particle size. Commercial Black Pearls 2000 {sup registered} (BP) and Vulcan {sup registered} XC-72 R (XC) carbon blacks were used. Capacitive properties of BP/RuO{sub 2} and XC/RuO{sub 2} composites were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in H{sub 2}SO{sub 4} solution. Capacitance values and capacitance distribution through the composite porous layer were found different if high- (BP) and low- (XC) surface-area carbons are used as supports. The aging time (particle size) of Ru oxide sol as well as the concentration of the oxide solid phase in the impregnating medium influenced the capacitive performance of prepared composites. While the capacitance of BP-supported oxide decreases with the aging time, the capacitive ability of XC-supported oxide is promoted with increasing oxide particle size. The increase in concentration of the oxide solid phase in the impregnating medium caused an improvement of charging/discharging characteristics due to pronounced pseudocapacitance contribution of the increasing amount of inserted oxide. The effects of these variables in the impregnation process on the energy storage capabilities of prepared nanocomposites are envisaged as a result of intrinsic way of population of the pores of carbon material by hydrous Ru oxide particle. (author)

  5. Optimized spray drying process for preparation of one-step calcium-alginate gel microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Popeski-Dimovski, Riste [Department of physic, Faculty of Natural Sciences and Mathematics, “ss. Cyril and Methodius” University, Arhimedova 3, 1000 Skopje, R. Macedonia (Macedonia, The Former Yugoslav Republic of)

    2016-03-25

    Calcium-alginate micro particles have been used extensively in drug delivery systems. Therefore we establish a one-step method for preparation of internally gelated micro particles with spherical shape and narrow size distribution. We use four types of alginate with different G/M ratio and molar weight. The size of the particles is measured using light diffraction and scanning electron microscopy. Measurements showed that with this method, micro particles with size distribution around 4 micrometers can be prepared, and SEM imaging showed that those particles are spherical in shape.

  6. ZnO-SiO{sub 2} based nanocomposites prepared by a modified sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Grigorie, Alexandra Carmen [Politehnica University Timisoara, Faculty of Industrial Chemistry and Environmental Engineering, 6 V. Parvan Blv., RO-300223, Timisoara (Romania); Muntean, Cornelia, E-mail: cornelia.muntean@upt.ro [Politehnica University Timisoara, Faculty of Industrial Chemistry and Environmental Engineering, 6 V. Parvan Blv., RO-300223, Timisoara (Romania); Politehnica University Timisoara, Research Institute for Renewable Energy, 2 Piata Victoriei, RO-300006, Timisoara (Romania); Vlase, Titus [West University of Timisoara, 4 V. Parvan Blv., RO-300223, Timisoara (Romania); Locovei, Cosmin [Politehnica University Timisoara, Research Institute for Renewable Energy, 2 Piata Victoriei, RO-300006, Timisoara (Romania); Politehnica University Timisoara, Faculty of Mechanical Engineering, 1 Mihai Viteazul Blv., RO-300222, Timisoara (Romania); Stefanescu, Mircea [Politehnica University Timisoara, Faculty of Industrial Chemistry and Environmental Engineering, 6 V. Parvan Blv., RO-300223, Timisoara (Romania)

    2017-01-15

    This paper presents a study on nanocomposites formation in ZnO-SiO{sub 2} systems with different ZnO:SiO{sub 2} molar ratios (1:4, 1:1, and 4:1), prepared employing a sol-gel method modified by an original procedure. The evolution of ZnO-SiO{sub 2} systems depending on the composition and temperature was studied by thermal analysis, Fourier transform infrared spectroscopy, X-ray diffractometry and transmission electron microscopy. Zn(II) carboxylate was synthesized in situ in hybrid silica gels by redox reaction between zinc nitrate and 1,3-propanediol. Its thermal decomposition at low temperatures led to ZnO dispersed in the pores of silica matrix. Only for the 4:1 system, at 400 and 600 °C, ZnO nanocrystallites (average size ∼9 nm) embedded in the amorphous silica matrix were obtained, the other systems being amorphous. Whatever the mixture composition is, above 600 °C, ZnO reacts with SiO{sub 2} to form zinc silicate. At 800 °C, for both 1:4 and 1:1 systems, poor crystallized β-Zn{sub 2}SiO{sub 4} and α-Zn{sub 2}SiO{sub 4} phases embedded in silica matrix were formed. Increasing the temperature, at 1000 °C, only for 1:1 system, β-Zn{sub 2}SiO{sub 4} phase turned into single phase α-Zn{sub 2}SiO{sub 4} (average crystallites size 28.3 nm). For 4:1 composition, at 800 and 1000 °C, systems consisting of ZnO and α-Zn{sub 2}SiO{sub 4} nanocrystallites dispersed in silica were obtained. - Highlights: • By modified sol-gel method, ZnO/SiO{sub 2} and Zn{sub 2}SiO{sub 4}/SiO{sub 2} nanocomposites were obtained. • ZnO dispersed in silica matrix results from zinc carboxylate thermal decomposition. • Zinc carboxylate was synthesized in situ in hybrid silica gels via redox reaction. • Evolution of ZnO in SiO{sub 2} matrix depends on temperature and system composition.

  7. Synthesis and photoluminescent properties of yttrium vanadate phosphor prepared by the non-hydrolytic sol–gel process

    International Nuclear Information System (INIS)

    Matos, Marcela G.; Faria, Emerson H. de; Rocha, Lucas A.; Calefi, Paulo S.; Ciuffi, Katia J.; Nassar, Eduardo J.; Sarmento, Victor Hugo Vitorino

    2014-01-01

    We used the non-hydrolytic sol–gel route to synthesize YVO 4 crystalline phases doped with europium III ion. We heat-treated the samples at 600, 800, and 1000 °C and characterized the materials by thermal analysis, X-ray diffraction, small-angle X-ray scattering, and photoluminescence. Larger weight loss occurred until 500 °C, ascribed to removal of residual precursor molecules. X-ray diffraction patterns evidenced YVO 4 phase formation at 600 °C. The crystallite size depended on the heat treatment temperature. SAXS showed that the nature of the system interfaces changed as a function of the thermal treatment. The excitation spectra of the samples displayed the charge transfer band. The photoluminescence data revealed the characteristic transition bands arising from the 5 D 0 → 5 F J (J=0, 1, 2, 3, and 4) manifolds under maximum excitation at the charge transfer band and the 5 L 6 level of the Eu 3+ ion. The 5 D 0 → 7 F 2 transition dominated the emission spectra, indicating that the Eu 3+ ion occupies a site without inversion center. The lifetime and quantum efficiency values were about 0.70 ms and 50%, respectively, corroborating literature results. -- Highlights: • This study described the preparation of the yttrium vanadate by non-hydrolytic sol–gel. • The SAXS curves can be interpreted from the fractal theory for a two-phase model. • The goal of the work is the preparation of the phosphors at low temperature. • The lifetimes depend on wavelength of the excitation

  8. Synthesis and photoluminescent properties of yttrium vanadate phosphor prepared by the non-hydrolytic sol–gel process

    Energy Technology Data Exchange (ETDEWEB)

    Matos, Marcela G.; Faria, Emerson H. de; Rocha, Lucas A.; Calefi, Paulo S.; Ciuffi, Katia J. [Universidade de Franca, Av. Dr. Armando Salles Oliveira, 201 Franca, SP, CEP 14404-600 (Brazil); Nassar, Eduardo J., E-mail: ejnassar@unifran.br [Universidade de Franca, Av. Dr. Armando Salles Oliveira, 201 Franca, SP, CEP 14404-600 (Brazil); Sarmento, Victor Hugo Vitorino [Universidade Federal de Sergipe, Av. Ver. Olimpio Grande s/n Itabaiana, SE, CEP 49500-000 (Brazil)

    2014-03-15

    We used the non-hydrolytic sol–gel route to synthesize YVO{sub 4} crystalline phases doped with europium III ion. We heat-treated the samples at 600, 800, and 1000 °C and characterized the materials by thermal analysis, X-ray diffraction, small-angle X-ray scattering, and photoluminescence. Larger weight loss occurred until 500 °C, ascribed to removal of residual precursor molecules. X-ray diffraction patterns evidenced YVO{sub 4} phase formation at 600 °C. The crystallite size depended on the heat treatment temperature. SAXS showed that the nature of the system interfaces changed as a function of the thermal treatment. The excitation spectra of the samples displayed the charge transfer band. The photoluminescence data revealed the characteristic transition bands arising from the {sup 5}D{sub 0}→{sup 5}F{sub J} (J=0, 1, 2, 3, and 4) manifolds under maximum excitation at the charge transfer band and the {sup 5}L{sub 6} level of the Eu{sup 3+} ion. The {sup 5}D{sub 0}→{sup 7}F{sub 2} transition dominated the emission spectra, indicating that the Eu{sup 3+} ion occupies a site without inversion center. The lifetime and quantum efficiency values were about 0.70 ms and 50%, respectively, corroborating literature results. -- Highlights: • This study described the preparation of the yttrium vanadate by non-hydrolytic sol–gel. • The SAXS curves can be interpreted from the fractal theory for a two-phase model. • The goal of the work is the preparation of the phosphors at low temperature. • The lifetimes depend on wavelength of the excitation.

  9. Reddish orange long afterglow phosphor Ca2SnO4:Sm3+prepared by sol-gel method

    International Nuclear Information System (INIS)

    Ju Zhenghua; Zhang Shuihe; Gao Xiuping; Tang Xiaoliang; Liu Weisheng

    2011-01-01

    Highlights: → A promising reddish orange emissive long afterglow phosphor Ca 2 SnO 4 :Sm 3+ prepared by sol-gel method was firstly reported. → The optics properties of Ca 2 SnO 4 :Sm 3+ were discussed. → Very useful tool, thermoluminscent technique was chosen to investigate the traps in the material. The results of thermoluminscent spectra indicating that the depth and number of traps are critical factors in determining their performance. → Furthermore, the phosphorescence mechanism was discussed successfully. → This work provides a potential approach to develop reddish orange light emitting long afterglow phosphor. - Abstract: A reddish orange light emissive long afterglow phosphor, Ca 2 SnO 4 :Sm 3+ was prepared by sol-gel method at lower temperature. The synthesized phosphors were characterized by X-ray diffraction, scanning electron micrograph images, photoluminescence spectra, afterglow decay curves and thermoluminescence spectra. Three emission peaks locate at 565 nm, 609 nm and 655 nm corresponding to CIE chromaticity coordinates of x = 0.53 and y = 0.47, which indicates the reddish orange light emitting. The fluorescent intensity and the afterglow characteristic depends on the concentration of Sm 3+ and the optimized concentration is 1.5 mol%. The afterglow decay curves are well fitted with triple-exponential decay models. The thermoluminescence glow curves show that the Sm 3+ induces suitable trap depth and result in the long afterglow phenomenon, and the corresponding increase or decrease in afterglow is associated with trap concentration, nearly no change in trap depth. The 1.5 mol% Sm 3+ -doped Ca 2 SnO 4 sample has the biggest trap concentration and exhibit the best afterglow characteristic, its' afterglow time is about 1 h. The phosphorescence mechanism of this long afterglow phosphor was discussed.

  10. Making MgO/SiO2 Glasses By The Sol-Gel Process

    Science.gov (United States)

    Bansal, Narottam P.

    1989-01-01

    Silicon dioxide glasses containing 15 mole percent magnesium oxide prepared by sol-gel process. Not made by conventional melting because ingredients immiscible liquids. Synthesis of MgO/SiO2 glass starts with mixing of magnesium nitrate hexahydrate with silicon tetraethoxide, both in alcohol. Water added, and transparent gel forms. Subsequent processing converts gel into glass. Besides producing glasses of new composition at lower processing temperatures, sol-gel method leads to improved homogeneity and higher purity.

  11. Fabrication and characterisation of selective solar absorber surfaces prepared by sol-gel technique

    CSIR Research Space (South Africa)

    Katumba, G

    2006-07-01

    Full Text Available characterization: The near normal spectral hemispherical reflect- ance, R, of the prepared samples was measured in the wavelength interval 0.3 to 20.0 μm1 using a Lambda 900 spec- trophotometer and a Bomem-Michel- son 110 FTIR spectrometer. Solar ab...

  12. Biochemical assessment of oxidative stress by the use of açai (Euterpe oleracea Martius gel in physically active individuals

    Directory of Open Access Journals (Sweden)

    Daniela Soares VIANA

    2016-01-01

    Full Text Available Abstract The relation between oxidative stress and inflammation induced by diseases and exercise has increased the interest in the benefits of antioxidant supplements in the improvement of health and physical and mental performance. The aim of this study was to evaluate the effectiveness of açai gel in reducing oxidative stress in individuals engaged in physical activities as well as their acceptance. Sensory evaluation was performed to determine its acceptability and the biochemical parameters related to immune profile and biomarkers of muscle, liver and oxidative stress, with and without the use of gel were evaluated. The appearance, sweetness and overall impression of the açai gel were considered good. It was observed a significant increase in CK enzyme, without the gel as well as the oxidative stress biomarkers, it was observed that the MDA (with and without gel a significant increase (p < 0.05. Through biochemical evaluation, it is concluded that the gel provided protection for some of parameters studied, since it modulated the immunological parameter reducing the lymphocyte activity and muscular stress. However, more studies must be carried out with a larger number of individuals to confirm the gel functionality.

  13. Biochemical assessment of oxidative stress by the use of açai (Euterpe oleracea Martius gel in physically active individuals

    Directory of Open Access Journals (Sweden)

    Daniela Soares VIANA

    Full Text Available Abstract The relation between oxidative stress and inflammation induced by diseases and exercise has increased the interest in the benefits of antioxidant supplements in the improvement of health and physical and mental performance. The aim of this study was to evaluate the effectiveness of açai gel in reducing oxidative stress in individuals engaged in physical activities as well as their acceptance. Sensory evaluation was performed to determine its acceptability and the biochemical parameters related to immune profile and biomarkers of muscle, liver and oxidative stress, with and without the use of gel were evaluated. The appearance, sweetness and overall impression of the açai gel were considered good. It was observed a significant increase in CK enzyme, without the gel as well as the oxidative stress biomarkers, it was observed that the MDA (with and without gel a significant increase (p < 0.05. Through biochemical evaluation, it is concluded that the gel provided protection for some of parameters studied, since it modulated the immunological parameter reducing the lymphocyte activity and muscular stress. However, more studies must be carried out with a larger number of individuals to confirm the gel functionality.

  14. Tetragonal zirconia quantum dots in silica matrix prepared by a modified sol-gel protocol

    Science.gov (United States)

    Verma, Surbhi; Rani, Saruchi; Kumar, Sushil

    2018-05-01

    Tetragonal zirconia quantum dots (t-ZrO2 QDs) in silica matrix with different compositions ( x)ZrO2-(100 - x)SiO2 were fabricated by a modified sol-gel protocol. Acetylacetone was added as a chelating agent to zirconium propoxide to avoid precipitation. The powders as well as thin films were given thermal treatment at 650, 875 and 1100 °C for 4 h. The silica matrix remained amorphous after thermal treatment and acted as an inert support for zirconia quantum dots. The tetragonal zirconia embedded in silica matrix transformed into monoclinic form due to thermal treatment ≥ 1100 °C. The stability of tetragonal phase of zirconia is found to enhance with increase in silica content. A homogenous dispersion of t-ZrO2 QDs in silica matrix was indicated by the mapping of Zr, Si and O elements obtained from scanning electron microscope with energy dispersive X-ray analyser. The transmission electron images confirmed the formation of tetragonal zirconia quantum dots embedded in silica. The optical band gap of zirconia QDs (3.65-5.58 eV) was found to increase with increase in zirconia content in silica. The red shift of PL emission has been exhibited with increase in zirconia content in silica.

  15. Structural and multiferroic properties of barium substituted bismuth ferrite nanocrystallites prepared by sol–gel method

    International Nuclear Information System (INIS)

    Anju; Agarwal, Ashish; Aghamkar, Praveen; Lal, Bhajan

    2017-01-01

    Nanocrystalline Bi 1-x Ba x FeO 3 (0≤x≤0.3) multiferroics were efficiently obtained by sol–gel method after sintering at 800 °C for one hour. The Ba substitution in BiFeO 3 (BFO) strongly modifies its structural and multiferroic properties. XRD studies revealed the structural transition from distorted rhombohedral (R3c) to pseudo-cubic (Pm3m) crystal symmetry. The magnetization increases appreciably for x=0.1, which is due to spin canting of magnetic moments at the nanoparticle surfaces and decreases afterward. From the temperature dependent magnetization studies, it is found that magnetic transition temperature (T N ) is 620 K for x=0 and 640 K for x=0.1. Besides, the maximum polarisation value decreases with increasing Ba content. SEM micrographs revealed the formation of cubic nanocrystallites with increased porosity on Ba substitution. FTIR analysis of the samples also supports the structural change towards increased crystal symmetry. - Highlights: • XRD studies revealed the structural transition from distorted rhombohedral (R3c) to pseudo-cubic (Pm3m) crystal symmetry. • The magnetization increases appreciably for x=0.1 and decreases afterward for higher Ba content. • Magnetic transition temperature (T N ) is found to be 620 K for x=0 and 640 K for x=0.1. • Maximum polarisation value is highest for x=0.1.

  16. Magnetic studies of cobalt doped barium hexaferrite nanoparticles prepared by modified sol-gel method

    International Nuclear Information System (INIS)

    Shalini, M. Govindaraj; Sahoo, Subasa C.

    2016-01-01

    M-type barium hexaferrite (BaFe_1_2O_1_9) and cobalt doped barium hexaferrite (BaFe_1_1CoO_1_9) nanopowders were synthesized by modified sol-gel auto-combustion technique and were annealed at 900°C in air for 4 hours. The annealed powders were studied in the present work and X-ray diffraction studies showed pure phase formation after annealing. The average grain size in the nanopowder sample was decreased after doping. Magnetization value of 60 emu/g was observed at 300 K for the barium hexaferrite and was reduced to 54 emu/g after doping. The coercivity of 5586 Oe was observed at 300 K for the undoped sample and was found to be decreased in the doped sample. As the measurement temperature was decreased from 300 K to 60 K, magnetization value was increased in both the samples compared to those at 300 K. The coercivity of the undoped sample was found to decrease whereas it was increased for the doped sample at 60 K. The observed magnetic properties may be understood on the basis of modified exchange interaction and anisotropy in the doped sample compared to that of pure barium hexaferrite.

  17. Sol-gel preparation of ion-conducting ceramics for use in thin films

    International Nuclear Information System (INIS)

    Steinhauser, M.I.

    1992-12-01

    A metal alkoxide sol-gel solution suitable for depositing a thin film of La 0.6 Sr 0.4 CoO 3 on a porous substrate has been developed; such films should be useful in fuel cell electrode and oxygen separation membrane manufacture. Crack-free films have been deposited on both dense and porous substrates by dip-coating and spin-coating techniques followed by a heat treatment in air. Fourier transform infrared spectroscopy was used to determine the chemical structure of metal alkoxide solution system. X-ray diffraction was used to determine crystalline phases formed at various temperatures, while scanning electron microscopy was used to determine physical characteristics of the films. Surface coatings have been successfully applied to porous substrates through the control of the substrate pore size, deposition parameters, and firing parameters. Conditions have been defined for which films can be deposited, and for which the physical and chemical characteristics of the film can be improved. A theoretical discussion of the chemical reactions taking place before and after hydrolysis in the mixed alkoxide solutions is presented, and the conditions necessary for successful synthesis are defined. Applicability of these films as ionic and electronic conductors is discussed

  18. Structural and multiferroic properties of barium substituted bismuth ferrite nanocrystallites prepared by sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Anju [Materials Science Lab, Department of Physics, Chaudhary Devi Lal University, Sirsa 125055 (India); Agarwal, Ashish [Department of Applied Physics, Guru Jambheshwar University of Science & Technology, Hisar 125001 (India); Aghamkar, Praveen, E-mail: praveenaghamkar@gmail.com [Materials Science Lab, Department of Physics, Chaudhary Devi Lal University, Sirsa 125055 (India); Lal, Bhajan [Department of Applied Sciences, Goverment Polytechnic for Women, Sirsa 125055 (India)

    2017-03-15

    Nanocrystalline Bi{sub 1-x}Ba{sub x}FeO{sub 3} (0≤x≤0.3) multiferroics were efficiently obtained by sol–gel method after sintering at 800 °C for one hour. The Ba substitution in BiFeO{sub 3} (BFO) strongly modifies its structural and multiferroic properties. XRD studies revealed the structural transition from distorted rhombohedral (R3c) to pseudo-cubic (Pm3m) crystal symmetry. The magnetization increases appreciably for x=0.1, which is due to spin canting of magnetic moments at the nanoparticle surfaces and decreases afterward. From the temperature dependent magnetization studies, it is found that magnetic transition temperature (T{sub N}) is 620 K for x=0 and 640 K for x=0.1. Besides, the maximum polarisation value decreases with increasing Ba content. SEM micrographs revealed the formation of cubic nanocrystallites with increased porosity on Ba substitution. FTIR analysis of the samples also supports the structural change towards increased crystal symmetry. - Highlights: • XRD studies revealed the structural transition from distorted rhombohedral (R3c) to pseudo-cubic (Pm3m) crystal symmetry. • The magnetization increases appreciably for x=0.1 and decreases afterward for higher Ba content. • Magnetic transition temperature (T{sub N}) is found to be 620 K for x=0 and 640 K for x=0.1. • Maximum polarisation value is highest for x=0.1.

  19. Wafer scale lead zirconate titanate film preparation by sol-gel method using stress balance layer

    International Nuclear Information System (INIS)

    Lu Jian; Kobayashi, Takeshi; Yi Zhang; Maeda, Ryutaro; Mihara, Takashi

    2006-01-01

    In this paper, platinum/titanium (Pt/Ti) film was introduced as a residual stress balance layer into wafer scale thick lead zirconate titanate (PZT) film fabrication by sol-gel method. The stress developing in PZT film's bottom electrode as well as in PZT film itself during deposition were analyzed; the wafer curvatures, PZT crystallizations and PZT electric properties before and after using Pt/Ti stress balance layer were studied and compared. It was found that this layer is effective to balance the residual stress in PZT film's bottom electrode induced by thermal expansion coefficient mismatch and Ti diffusion, thus can notably reduce the curvature of 4-in. wafer from - 40.5 μm to - 12.9 μm after PZT film deposition. This stress balance layer was also found effective to avoid the PZT film cracking even when annealed by rapid thermal annealing with heating-rate up to 10.5 deg. C/s. According to X-ray diffraction analysis and electric properties characterization, crack-free uniform 1-μm-thick PZT film with preferred pervoskite (001) orientation, excellent dielectric constant, as high as 1310, and excellent remanent polarization, as high as 39.8 μC/cm 2 , can be obtained on 4-in. wafer

  20. Synthesis of ZrO2-TiO2 mixed oxide spheres by sol-gel method and investigation of Sr adsorption behaviours by experimental design approach

    International Nuclear Information System (INIS)

    Cetinkaya, B.; Tel, H.; Altas, Y.; Eral, M.; Sert, S.; Inan, S.; Talip, Z.

    2009-01-01

    ZrO 2 -TiO 2 gel spheres were synthesized by sol-gel method. Zr-Ti sol solution was prepared from ZrCl 4 and TiCl 4 (1:1 mol ratio) via partial neutralization by ammonia to obtain 0.5M final metal concentration. ZrO 2 -TiO 2 sol was transferred to vibrating nozzle system by peristaltic pump. Vibrating nozzle system was designed and produced in Institute of Nuclear Sciences. Sol drops formed by nozzle were gelled in gelation column. Synthesized ZrO 2 -TiO 2 spheres were aged for 24h then washed with deionized water and dried in oven. Sr + 2 adsorption behaviors of ZrO 2 -TiO 2 mixed oxides were investigated with central composite design (CCD). Four independent parameters (pH, initial Sr + 2 concentration, temperature and contact time) were investigated with 7 replicates at central points. Sorption data have been interpreted in terms of Langmuir, Freundlich and Dubinin Radushkevich equations. Thermodynamic parameters for the sorption system have been determined.

  1. Preparation of a gel of zirconium molybdate for use in the generators of 99 Mo - 99m Tc prepared with 99 Mo produced by the 98 Mo(n,γ)99 Mo reaction

    International Nuclear Information System (INIS)

    Osso Junior, Joao A.; Lima, Ana Lucia V.P.; Silva, Nestor C. da; Nieto, Renata C.; Velosa, Adriana C. de

    1998-01-01

    IPEN develops a project concerning the preparation of a gel of Zirconium Molybdate for use in the generators of 99 Mo- 99m Tc . 99m Tc is the most used radioisotope in nuclear medicine diagnosis procedures and nowadays the generators are being prepared with imported 99 Mo, produced by 235 U fission. The production of 99 Mo by the 98 Mo(n, γ) 99 Mo reaction is now possible because of the power upgrade of IPEN's IEA-R1 reactor, from 2 to 5 MW. This work describes the preparation method of Zirconium Molybdate gel that will be used in the 99 Mo- 99m Tc generators. The gel is prepared by the chemical reaction between Mo, in Mo O 3 form, and Zr, in Zr O Cl 2 .8H 2 O form. After the reaction, the gel is filtered, dried and cracked with saline solution. The product is then loaded into glass columns for use as 99m Tc generator. The results showed the good quality of the gel prepared at laboratory level and of the generators evaluated. (author)

  2. Iron oxide nanoparticles stabilized inside highly ordered ...

    Indian Academy of Sciences (India)

    CdS nanoparticles prepared in reverse micellar system was incorporated into ... The molar ratio of various constituents of the hydrothermal gel was ... other synthesis techniques for the preparation of iron oxide nanocomposites using.

  3. Preparation of new crystal forms via photochemical, mechanochemical and sol-gel methods

    OpenAIRE

    D’Agostino, Simone

    2012-01-01

    This work of thesis involves various aspects of crystal engineering. Chapter 1 focuses on crystals containing crown ether complexes. Aspects such as the possibility of preparing these materials by non-solution methods, i.e. by direct reaction of the solid components, thermal behavior and also isomorphism and interconversion between hydrates are taken into account. In chapter 2 a study is presented aimed to understanding the relationship between hydrogen bonding capability and shape of the...

  4. Lattice Constant Dependence on Particle Size for Ceria prepared from a Citrate Sol-Gel

    International Nuclear Information System (INIS)

    Morris, V N; Farrell, R A; Sexton, A M; Morris, M A

    2006-01-01

    High surface area ceria nanoparticles have been prepared using a citrate solgel precipitation method. Changes to the particle size have been made by calcining the ceria powders at different temperatures, and X-ray methods used to determine their lattice parameters. The particle sizes have been assessed using transmission electron microscopy (TEM) and the lattice parameter found to fall with decreasing particle size. The results are discussed in the light of the role played by surface tension effects

  5. Moessbauer studies of SnO2 powders doped with dilute 57Fe, prepared by a sol-gel method

    International Nuclear Information System (INIS)

    Nomur, K.; Sakuma, J.; Takeda, M.

    2006-01-01

    Diluted magnetic semiconductor (DMS) is prospected as new materials with both semiconductor and magnetic properties. In order to confirm these phenomena, we prepared the powders of SnO 2 doped with various amount of 57 Fe by a sol-gel method. Various compositions of Sn 1-x 57 Fe x O 2 were obtained by mixing some ratio of Fe 3+ nitrate solution and acetylacetonate Sn 4+ complex in the ethylene glycol and citric acid solution. The solutions were evaporated, ashed at around 200 grad C, and finally annealed at 500 grad C, 600 grad C, and 650 grad C, respectively. These Sn 1-x 57 Fe x O 2 (x=0.005, 0.01, 0.03 and 0.05) were measured by XRD, VSM, and Moessbauer spectrometry. The prepared powder samples were confirmed to be a rutile structure, but iron compounds were not detected by XRD. Moessbauer spectra of Sn 1-x 57 Fe x O 2 prepared at 500 grad C were shown in Fig. 1. A small amount of broad sextets were observed in MS spectra of Sn 1-x 57 Fe x O 2 in addition to paramagnetic components. The relative intensity seems to be strong with the decrease of the amount of doped Fe. Moessbauer spectrum at 10 K shows clearly the magnetic components. The magnetic sextet was observed in MS spectra of samples prepared at 650 grad C, but the magnetic behavior weakened because of antiferromagnetic α-Fe 2 O 3 , produced due to the phase separation at high temperatures. (authors)

  6. Sol-gel chemistry applied to the synthesis of polymetallic oxides including actinides reactivity and structure from solution to solid state

    International Nuclear Information System (INIS)

    Lemonnier, St.

    2006-02-01

    Minor actinides transmutation is studied at present in order to reduce the radiotoxicity of nuclear waste and the assessment of its technical feasibility requires specific designed materials. When considering americium, yttria stabilized zirconia (Am III YII Zriv)Or x is among the ceramic phases that one which presents the required physico-chemical properties. An innovative synthesis of this mixed oxide by sol-gel process is reported in this manuscript. The main aim of this work is to adjust the reactivity of the different metallic cations in aqueous media using complexing agent, in order to initiate a favourable interaction for a homogeneous elements repartition in the forming solid phase. The originality of the settled synthesis lies on an in-situ formation of a stable and monodisperse nano-particles dispersion in the presence of acetylacetone. The main reaction mechanisms have been identified: the sol stabilisation results from an original interaction between the three compounds (Zrly, trivalent cations and acetylacetone). The sol corresponds to a structured system at the nanometer scale for which zirconium and trivalent cations are homogeneously dispersed, preliminary to the sol-gel transition. Furthermore, preliminary studies were carried out with a view to developing materials. They have demonstrated that numerous innovative and potential applications can be developed by taking advantage of the direct and controlled formation of the sol and by adapting the sol-gel transition. The most illustrating result is the preparation of a sintered pellet with the composition Am0,13Zro,73Yo,0901,89 using this approach. (author)

  7. Simplified sample preparation method for protein identification by matrix-assisted laser desorption/ionization mass spectrometry: in-gel digestion on the probe surface

    DEFF Research Database (Denmark)

    Stensballe, A; Jensen, Ole Nørregaard

    2001-01-01

    /ionization-time of flight mass spectrometry (MALDI-TOF-MS) is used as the first protein screening method in many laboratories because of its inherent simplicity, mass accuracy, sensitivity and relatively high sample throughput. We present a simplified sample preparation method for MALDI-MS that enables in-gel digestion...... for protein identification similar to that obtained by the traditional protocols for in-gel digestion and MALDI peptide mass mapping of human proteins, i.e. approximately 60%. The overall performance of the novel on-probe digestion method is comparable with that of the standard in-gel sample preparation...... protocol while being less labour intensive and more cost-effective due to minimal consumption of reagents, enzymes and consumables. Preliminary data obtained on a MALDI quadrupole-TOF tandem mass spectrometer demonstrated the utility of the on-probe digestion protocol for peptide mass mapping and peptide...

  8. Preparation of Organic-Inorganic Multifunctional Nanocomposite Coating via Sol-Gel Routes

    International Nuclear Information System (INIS)

    Li Haoying; Chen Yunfa; Ruan Chengxiang; Gao Weimin; Xie Yusheng

    2001-01-01

    The inorganic-organic nanocomposite coatings are prepared on poly(methyl methacrylate) (PMMA) substrate by the spinning technique which involves incorporating homogeneously nanosized ZnO particle into the molecular inorganic-organic hybrid matrices. The hybrid matrices are derived from tetraethoxyasilane (TEOS) and 3-glycidoxypropyltrimethoxyailane (GLYMO). To avoid the destruction of the polymer structure caused by ZnO and modify the interface between nanoparticles and organic groups, ZnO was first surface-coated with SiO 2 from hydrolyzed TEOS using ammonia water as catalyst. The coatings thus obtained are dense, flexible, abrasion resistant and UV absorbent

  9. Synthesis and photocatalytic properties of porous TiO2 films prepared by ODA/sol-gel method

    International Nuclear Information System (INIS)

    Zhang Wenjie; Bai Jiawei

    2012-01-01

    Porous TiO 2 films were deposited on SiO 2 pre-coated glass-slides by sol-gel method using octadecylamine (ODA) as template. The amount of ODA in the sol played an important role on the physicochemical properties and photocatalytic performance of the TiO 2 films. The films prepared at different conditions were all composed of anatase titanium dioxide crystals, and TiO 2 crystalline size got larger with increasing ODA amount. The maximum specific surface area of 41.5 m 2 /g was obtained for TiO 2 powders prepared from titanium sol containing 2.0 g ODA. Methyl orange degradation rate was enhanced along with increasing ODA amount and reached the maximal value at 2.0 g addition of ODA. After 40 min of UV-light irradiation, methyl orange degradation rate reached 30.5% on the porous film, which was about 10% higher than that on the smooth film. Porous TiO 2 film showed almost constant activity with slight decrease from 30.5% to 28.5% after 4 times of recycles.

  10. Characteristics and Laser Performance of Yb3+-Doped Silica Large Mode Area Fibers Prepared by Sol–Gel Method

    Directory of Open Access Journals (Sweden)

    Shikai Wang

    2013-12-01

    Full Text Available Large-size 0.1 Yb2O3–1.0 Al2O3–98.9 SiO2 (mol% core glass was prepared by the sol–gel method. Its optical properties were evaluated. Both large mode area double cladding fiber (LMA DCF with core diameter of 48 µm and large mode area photonic crystal fiber (LMA PCF with core diameter of 90 µm were prepared from this core glass. Transmission loss at 1200 nm is 0.41 dB/m. Refractive index fluctuation is less than 2 × 10−4. Pumped by 976 nm laser diode LD pigtailed with silica fiber (NA 0.22, the slope efficiency of 54% and “light-to-light” conversion efficiency of 51% were realized in large mode area double cladding fiber, and 81 W laser power with a slope efficiency of 70.8% was achieved in the corresponding large mode area photonic crystal fiber.

  11. Preparation of CuAlO2 Thin Films by Sol-Gel Method Using Nitrate Solution Dip-Coating

    Directory of Open Access Journals (Sweden)

    Ehara Takashi

    2016-01-01

    Full Text Available CuAlO2 thin films are prepared by sol-gel dip-coating followed by annealing in nitrogen atmosphere using copper nitrate and aluminum nitrate as metal source materials. X-ray diffraction (XRD patterns show (003, (006 and (009 oriented peaks of CuAlO2 at annealing temperature of 800 – 1000°C. This result indicates that the CuAlO2 films prepared in the present work are c-axis oriented. XRD peak intensity increase with annealing temperature and becomes maximum at 850°C. The CuAlO2 XRD peak decreased at annealing temperature of 900°C with appearance of a peak of CuO, and then increased again with annealing temperature until 1000 °C. The films have bandgap of 3.4 eV at annealing temperature of 850°C in which the transparency becomes the highest. At the annealing temperature of 850°C, scanning electron microscope (SEM observation reveals that the films are consist of amorphous fraction and microcrystalline CuAlO2 fraction.

  12. Preparation and characterization of Sio2CaCl2 nanocomposite by the sol-gel method

    International Nuclear Information System (INIS)

    Tohidi, S. H.; Ziaie, F.; Abdolmaleki, A.

    2009-01-01

    The SiO 2 CaCl 2 hybrid porous materials were prepared by the sol-gel method. This process was conducted by the hydrolysis and condensation of Tetraethyl orthosilicate by replacement of ethanol from alcogel and drying at the ambient temperature to obtain xerogel structure. The alcogel samples were synthesized from Tetraethyl orthosilicate, EtOH, H 2 O, HCl, NH 4 OH and CaCl 2 , while the total molar ratio of the compounds was 1: 9: 4: 8 x 10 -4 , 8 x 10 -3 , respectively. Xerogel containing 30 wt % of CaCl 2 (dry matter) was prepared and characterized by Scanning Electron Microscopy, Transmission Electron Microscopy, Fourier Transmittance Infra Red spectrum, Energy Dispersive X-ray and Thermal Gravimetric Analysis systems. The results obtained from Scanning Electron Microscopy and Energy Dispersive X-ray showed the micrograph of CaCl 2 on the silica and chemical elemental analysis, respectively. On the other hand, The Transmission Electron Microscopy micrograph confirmed average particle size of SiO 2 -CaCl 2 about 50 nm and Fourier Transmittance Infra Red spectrum described the functional groups of the nano composite. The thermal analysis of SiO 2 -CaCl 2 nano composite was performed using Thermal Gravimetric Analysis system and the results showed that the suitable temperature for initial thermal treatment was about 200 d eg C .

  13. Development of novel hybrid materials based on poly(2-aminophenyl disulfide)/silica gel: Preparation, characterization and electrochemical studies

    Science.gov (United States)

    Benyakhou, S.; Belmokhtar, A.; Zehhaf, A.; Benyoucef, A.

    2017-12-01

    Hydrochloric acid functionalized silica gel (SiO2) has been successfully used for the grafting of poly(2-Aminophenyl disulfide) (poly(2APhS)) moieties through in-situ polymerization in the presence of ammonium peroxodisulfate (APS) as oxidant. The organic-inorganic hybrid (poly(2APhS)/SiO2 with different amounts of SiO2: 0.5 g, 1.5 g and 2 g) were thoroughly characterized through powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and ultraviolet spectroscopy (UV) measurements. The results confirm the successful formation of the poly(2APhS)/SiO2 composite. The surface morphology of the samples was characterized by transmission electron microscopy (TEM). The obtained images show the formation of poly(2APhS) on surface of silica gel. Although the incorporation of SiO2 nanoparticles reduces the electric conductivity of the poly(2APhS), the resulting samples still keep high conductivities, ranging between 8.2 × 10-4 to 1.1 × 10-6 S cm-1. The electrochemical properties of the composite were characterized by the cyclic voltammetry. The comparison between the different samples shows that the electrochemical activity is significantly depending on the amount of added SiO2. There is a clear and good electroactivity for poly(2APhS)/SiO2 with amounts of SiO2: 0.5 g and 1.5 g, respectively, compared to that observed in materials nanocomposite with amounts of SiO2: 2.0 g. However, that effect may be explained by a decrease of polymer in surface area with increase amount of SiO2 nanoparticle.

  14. Preparation of nitrogen-doped titania using sol-gel technique and its photocatalytic activity

    International Nuclear Information System (INIS)

    Qin Haoli; Gu Guobang; Liu Song

    2008-01-01

    Yellowish nitrogen-doped titania was produced through sol-gel method at room temperature, with the elemental nitrogen derived from aqua ammonia. The titania catalysts were characterized using TG-DSC, XRD, BET, TEM, and UV-vis diffuse reflectance spectrophotometer. Methyl orange (MO) and 2-mercaptobenzothiazole (MBT) were used in this study as model chemicals and both the adsorption isotherm and photocatalytic activity of the nitrogen-doped titania catalysts were evaluated based on the MO and MBT photodegradation in aqueous solution under UV and visible light, respectively. The results showed that all titania catalysts were anatase. The crystallite size of nitrogen-doped ones increased with the increase of N/Ti proportion, both the adsorption capacity and adsorption equilibrium constants of the nitrogen-doped titania catalysts were improved by the doping of nitrogen. The doping of nitrogen could extend the absorption shoulder into the visible-light region, thus nitrogen-doped titania possessed visible-light activity illustrated by that higher capability of degradation of MO and MBT under the irradiation of visible light, whereas the pure ones showed little such kind of visible-light activity. The kinetics of the MO and MBT photodegradation using different nitrogen-doped titania were also studied, the experiments demonstrated that there was an optimum N/Ti proportion of 4 mol% to exhibit the highest visible-light activity. The UV activity of nitrogen-doped titania catalysts were worse than that of the pure one and Degussa P-25. In addition, nitrogen-doped titania had weakened appreciably activity in the visible-light region as the N/Ti proportion increased, while a reverse relationship exists for the UV light. It was concluded that the enhancement of MO and MBT photodegradation using the nitrogen-doped titania catalysts mainly involved in both the improvement of the organic substrate adsorption in catalysts suspension and the enhancement of the separation of electron

  15. Detection by denaturing gradient gel electrophoresis of ammonia-oxidizing bacteria in microcosms of crude oil-contaminated mangrove sediments.

    Science.gov (United States)

    dos Santos, A C F; Marques, E L S; Gross, E; Souza, S S; Dias, J C T; Brendel, M; Rezende, R P

    2012-01-27

    Currently, the effect of crude oil on ammonia-oxidizing bacterium communities from mangrove sediments is little understood. We studied the diversity of ammonia-oxidizing bacteria in mangrove microcosm experiments using mangrove sediments contaminated with 0.1, 0.5, 1, 2, and 5% crude oil as well as non-contaminated control and landfarm soil from near an oil refinery in Camamu Bay in Bahia, Brazil. The evolution of CO(2) production in all crude oil-contaminated microcosms showed potential for mineralization. Cluster analysis of denaturing gradient gel electrophoresis-derived samples generated with primers for gene amoA, which encodes the functional enzyme ammonia monooxygenase, showed differences in the sample contaminated with 5% compared to the other samples. Principal component analysis showed divergence of the non-contaminated samples from the 5% crude oil-contaminated sediment. A Venn diagram generated from the banding pattern of PCR-denaturing gradient gel electrophoresis was used to look for operational taxonomic units (OTUs) in common. Eight OTUs were found in non-contaminated sediments and in samples contaminated with 0.5, 1, or 2% crude oil. A Jaccard similarity index of 50% was found for samples contaminated with 0.1, 0.5, 1, and 2% crude oil. This is the first study that focuses on the impact of crude oil on the ammonia-oxidizing bacterium community in mangrove sediments from Camamu Bay.

  16. Powder of a copper oxide superconductor precursor, fabrication process and use for the preparation of superconducting oxide

    International Nuclear Information System (INIS)

    Dehaudt, P.

    1990-01-01

    The precursor powder comprises at least a copper compound (hydroxide, oxide and hydroxynitrates), at least a rare earth and/or yttrium compound (nitrates, hydroxides and hydroxynitrates) or bismuth oxide and at least an alkaline earth nitrate. It can be prepared by atomization drying of a suspension a copper precipitate or coprecipitate and other elements of the superconducting oxide in solution [fr

  17. Aggregation and growth of ZnO quantum dots prepared from sol-gel chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Santilli, C.V.; Pulcinelli, S.H.; Caetano, B.L. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Araraquara, SP (Brazil); Briois, V.B [Synchrotron SOLEIL, Saint-Aubin (France)

    2016-07-01

    Full text: Herein we discuss in depth the mechanisms of growth control of ZnO quantum dots (Q-dot) prepared from the zinc oxy-acetate ethanolic solution by the addition of LiOH. Through in situ monitoring of Q-dot radii and of aggregation index calculated from UV-Vis absorption spectra and small-angle X-ray scattering (SAXS) the aggregation and growth of ZnO nanocrystal was well described from two kinetic models: during the first step (t< 50 min) the structural evolution is controlled by the coalescence caused by the oriented attachment between the nanocrystal aggregates while at the advanced time (t> 50 min) the Q-dot coarsening follows the Ostwald ripening (OR) mechanism. From the higher oriented attachment efficiency observed here as compared with early reported synthesis using NaOH and KOH, we propose an universal mechanism to control coalescence and coarsening of ZnO nanocrystal provided from the shield caused by the adsorption of the alkali cation. From X-ray diffraction and transmission electron microscopy results we demonstrate that this mechanism is also useful to prepare Q-dot powders with controlled size. (author)

  18. Photochemical preparation of aluminium oxide layers via vacuum ultraviolet irradiation of a polymeric hexanoato aluminium complex

    International Nuclear Information System (INIS)

    Wennrich, L.; Khalil, H.; Bundesmann, C.; Decker, U.; Gerlach, J.W.; Helmstedt, U.; Manova, D.; Naumov, S.; Prager, L.

    2013-01-01

    By means of photochemical conversion of thin layers of a polymeric hexanoato aluminium complex as the precursor, thin aluminium oxide layers were prepared onto silicon wafers. The precursor compound was synthesized and characterized by several analytical techniques like NMR, FTIR, XPS, ICP, and found to be a polymeric aluminium-containing coordination compound which has been proposed to be a hydroxo-bridged aluminium chain with pendant hexanoyl side-chains ascertained as catena-poly[{di(κ-O,O-hexanoato)aluminium}(μ-hydroxo)] (PHAH). Thin layers deposited from a solution of PHAH in toluene onto silicon wafers were irradiated using VUV radiation from a xenon excimer lamp. The layers were characterized by XPS, XRD, XRR, and spectroscopic ellipsometry. VUV radiation with a radiant exposure of E = 36 J cm −2 led to almost carbon-free amorphous layers with a composition close to that of alumina having a density of about 2.1 g cm −3 . Thus, using the example of a polymeric aluminium complex, the potential of the photochemical conversion of metal complexes into oxides could be shown as an alternative method, in addition to sol–gel techniques, for the generation of thin plane metal-oxide layers at normal temperature and pressure. Highlights: ► A polymeric aluminium complex was synthesized and characterized by NMR, FTIR, XPS and ICP. ► Thin layers of the compound were irradiated using vacuum-UV radiation and converted to AlO x . ► Quantum-chemical calculations explain the conversion mechanism.

  19. Characterization and hydrogen gas sensing properties of TiO{sub 2} thin films prepared by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Haidry, Azhar Ali [Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, Bratislava (Slovakia); Puskelova, Jarmila [Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, Bratislava (Slovakia); Plecenik, Tomas; Durina, Pavol; Gregus, Jan; Truchly, Martin; Roch, Tomas; Zahoran, Miroslav [Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, Bratislava (Slovakia); Vargova, Melinda [Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, Bratislava (Slovakia); Kus, Peter; Plecenik, Andrej [Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, Bratislava (Slovakia); Plesch, Gustav, E-mail: plesch@fns.uniba.sk [Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, Bratislava (Slovakia)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Preparation and characterization of hydrogen sensing TiO{sub 2} thin films by sol-gel method. Black-Right-Pointing-Pointer The annealing effect on the structure, electrical, optical and sensing properties was studied. Black-Right-Pointing-Pointer The best sensitivity show the films composed of rutile with grain size of {approx}100 nm. - Abstract: Thin films of titanium dioxide with thickness of about 150 nm were deposited by spin coating method on a sapphire substrate from a sol-gel and annealed at various temperatures (from 600 Degree-Sign C to 1000 Degree-Sign C). Structural, optical and hydrogen gas sensing properties of the films were investigated. The annealing temperatures from 600 to 800 Degree-Sign C led to anatase phase with grain size in the range of 14-28 nm. Further increase of the annealing temperature resulted in transformation to rutile phase with larger grain size of about 100-120 nm. The optical band gap tended to decrease with increasing annealing temperature. The estimated values of activation energy for charge transport were in the range of 0.6-1.0 eV for films annealed at temperatures from 600 Degree-Sign C to 800 Degree-Sign C and 0.37-0.38 eV for films annealed at 900 Degree-Sign C and 1000 Degree-Sign C. The films annealed at 900 Degree-Sign C and 1000 Degree-Sign C showed better hydrogen sensitivity, what can be at least partially caused by their higher surface roughness.

  20. Preparation and characterization of the titanium dioxide thin films used for pH electrode and procaine drug sensor by sol-gel method

    International Nuclear Information System (INIS)

    Liao Yihung; Chou, J.-C.

    2009-01-01

    We used titanium dioxide (TiO 2 ) as the sensing layer of an ion selective pH sensor electrode, and as the substrate for a procaine drug sensitive membrane sensor. The TiO 2 thin films were prepared using sol-gel spin coating technology. We adopted the Ti(OC 4 H 9 ) 4 as the precursor, and added an ethanol solute to obtain the TiO 2 sol. The sol-gel was spun coated onto the indium tin oxide (ITO) substrate. The drug sensitive membrane was coated on the TiO 2 film. We then measured the I DS -V G curves of the TiO 2 ion selective electrode (ISE) pH sensor in pH buffer solutions that had different pH concentrations using a Keithley 236 Semiconductor Parameter Analyzer instrument. The procaine concentration was measured from 10 -2 M to 10 -6 M with the drug sensitive membrane using a HP 34401A Digital Multimeter. We prepared the TiO 2 ISE pH sensor and obtained a high pH sensitivity of 58.73 mV/pH. Uniform TiO 2 films surface structures, with an average roughness (Ra) of 10.211 nm and root mean square roughness (Rms) of 13.01 nm were obtained. The drift effect of the titanium dioxide ion selective pH sensor electrode is 1.97 mV h -1 . The sensitivity of the procaine drug sensor is 55.03 mV pC -1 between 1.0 x 10 -2 mol L -1 and 1.0 x 10 -6 mol L -1 procaine concentrations. The detection limit is 5.0 x 10 -6 mol L -1 . The response time to reach 90% output voltage is 16 s. Forty seconds are required to reach 95% output voltage. The procaine drug sensor 1 x 10 -3 mol L -1 drift test is 3.64 mV h -1 and the variation in output voltage of the repeated measurement is less than 7.4 mV

  1. Preparation of LiMO2(M=Co,Ni) cathode materials for intermediate temperature fuel cells by sol-gel processes

    DEFF Research Database (Denmark)

    Tao, S.W.; Wu, Q.Y.; Zhan, Z.L.

    1999-01-01

    LiMO2 (M = Co, Ni) was prepared by complexing sol-gel processes. The phase and thermal stability were characterized by XRD and TG analyses. LiCoO2 and LiNiO2 phases are formed around 400 degrees C and 700 degrees C respectively in our synthesis process. LiNiO2 exhibit higher electrical conductivity...

  2. Preparation of uranium-based oxide catalysts; Preparation de catalyseurs oxydes a base d'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Bressat, R [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1965-07-01

    We have studied the thermal decomposition of uranyl and uranium IV oxalates as a mean of producing uranium dioxide. We have isolated the main intermediate phases of the decompositions and have indexed the lines of their X-ray diffraction patterns. The oxides produced by the decomposition are ill-defined and unstable: they strongly absorb atmospheric oxygen with modification of the composition and, in certain cases, of the structure (pyrophoric oxide). With a view to obtaining stable oxides, we have prepared mixed uranium-thorium oxalates. In order to prepare an oxalate having a homogeneous composition, it is necessary to adopt a well-defined preparation method: the addition of solutions of thorium and uranium IV nitrates to a continually saturated oxalic acid solution. The mixed oxide obtained from the thermal decomposition of an oxalate U{sub x}Th{sub 1-x}(C{sub 2}O{sub 4}){sub 2}, 2 H{sub 2}O at 500 C for 24 hours in a current of oxygen leads to a cubic structure which is well-defined both in the bulk and superficially when x is less than 0.35. Above this atomic concentration of uranium, some uranium moves out of the lattice in the form of UO{sub 3} or U{sub 3}O{sub 8} according to the temperature. The mixed oxide is not stoichiometric,(U{sub x}Th{sub 1-x}O{sub 2+y}) and the average degree of oxidation of the uranium varies with the temperature and partial oxygen pressure. The oxides thus formed have a high surface area. By dissolving the mixed oxalates in a concentrated solution of ammonium oxalate, it is possible to deposit the catalyst on a support, but the differences in the solubilities of the thorium and uranium IV oxalates in the ammonium oxalate make it impossible to prepare double salts formed either of thorium and uranium and of ammonium. (author) [French] Nous avons etudie la decomposition thermique des oxalates d'uranyle et d'uranium IV en vue d'aboutir au dioxide d'uranium. Nous avons pu isoler les principales phases intermediaires des decompositions

  3. Graphene oxide powders with different oxidation degree, prepared by synthesis variations of the Hummers method

    International Nuclear Information System (INIS)

    Guerrero-Contreras, Jesus; Caballero-Briones, F.

    2015-01-01

    Graphene oxide (GO) powders with different oxidation degree estimated through the relative intensity of the infrared absorption bands related to oxygen containing groups were prepared through variations of the Hummers method. The GO powders were analyzed by Transmission Electron Microscopy, Energy dispersive spectroscopy, X-ray Photoelectron Spectroscopy, Fourier Transform Infrared Spectroscopy, Raman spectroscopy, X-ray Diffraction, UV–VIS spectroscopy and Electrical Resistance measurements. Several square micron GO sheets with low wrinkling were obtained. Oxygen to carbon ratio is around 0.2 in all the samples although a strong variance in the relative intensity of the oxygen related infrared bands is evident. Thus, the oxidation degree was estimated from the FTIR measurements using the quotient between the C–O related bands area to the total area under the spectra. FTIR shows presence of hydroxyl (–OH), epoxy (C–O–C), carboxyl (–COOH) and carbonyl (C=O) moieties and evidence of intermolecular interactions between adjacent groups. These interactions influence the exfoliation degree, the absorbance of the GO suspensions, as well as the electrical resistance, while the crystalline domain sizes, estimated from XRD and Raman do not show a noticeable behavior related with the composition and molecular structure. The results indicate that the electrical resistance is influenced mainly by the surface chemistry of the GO powders and not only by the O/C ratio. The control of the surface chemistry of GO powders would allow their use as additives in organic bulk heterojunction solar cells with enhanced photoconversion efficiency. - Highlights: • Powders of graphene oxide with different oxidation degree were prepared through variations of the Hummers method. • Raman spectroscopy and XRD demonstrated similar crystallite domain size in the samples. • Electrical resistance, exfoliation degree and optical absorption depend on the molecular structure.

  4. Graphene oxide powders with different oxidation degree, prepared by synthesis variations of the Hummers method

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero-Contreras, Jesus; Caballero-Briones, F., E-mail: fcaballero@ipn.mx

    2015-03-01

    Graphene oxide (GO) powders with different oxidation degree estimated through the relative intensity of the infrared absorption bands related to oxygen containing groups were prepared through variations of the Hummers method. The GO powders were analyzed by Transmission Electron Microscopy, Energy dispersive spectroscopy, X-ray Photoelectron Spectroscopy, Fourier Transform Infrared Spectroscopy, Raman spectroscopy, X-ray Diffraction, UV–VIS spectroscopy and Electrical Resistance measurements. Several square micron GO sheets with low wrinkling were obtained. Oxygen to carbon ratio is around 0.2 in all the samples although a strong variance in the relative intensity of the oxygen related infrared bands is evident. Thus, the oxidation degree was estimated from the FTIR measurements using the quotient between the C–O related bands area to the total area under the spectra. FTIR shows presence of hydroxyl (–OH), epoxy (C–O–C), carboxyl (–COOH) and carbonyl (C=O) moieties and evidence of intermolecular interactions between adjacent groups. These interactions influence the exfoliation degree, the absorbance of the GO suspensions, as well as the electrical resistance, while the crystalline domain sizes, estimated from XRD and Raman do not show a noticeable behavior related with the composition and molecular structure. The results indicate that the electrical resistance is influenced mainly by the surface chemistry of the GO powders and not only by the O/C ratio. The control of the surface chemistry of GO powders would allow their use as additives in organic bulk heterojunction solar cells with enhanced photoconversion efficiency. - Highlights: • Powders of graphene oxide with different oxidation degree were prepared through variations of the Hummers method. • Raman spectroscopy and XRD demonstrated similar crystallite domain size in the samples. • Electrical resistance, exfoliation degree and optical absorption depend on the molecular structure.

  5. Integrating nanohybrid membranes of reduced graphene oxide: chitosan: silica sol gel with fiber optic SPR for caffeine detection

    Science.gov (United States)

    Kant, Ravi; Tabassum, Rana; Gupta, Banshi D.

    2017-05-01

    Caffeine is the most popular psychoactive drug consumed in the world for improving alertness and enhancing wakefulness. However, caffeine consumption beyond limits can result in lot of physiological complications in human beings. In this work, we report a novel detection scheme for caffeine integrating nanohybrid membranes of reduced graphene oxide (rGO) in chitosan modified silica sol gel (rGO: chitosan: silica sol gel) with fiber optic surface plasmon resonance. The chemically synthesized nanohybrid membrane forming the sensing route has been dip coated over silver coated unclad central portion of an optical fiber. The sensor works on the mechanism of modification of dielectric function of sensing layer on exposure to analyte solution which is manifested in terms of red shift in resonance wavelength. The concentration of rGO in polymer network of chitosan and silica sol gel and dipping time of the silver coated probe in the solution of nanohybrid membrane have been optimized to extricate the supreme performance of the sensor. The optimized sensing probe possesses a reasonably good sensitivity and follows an exponentially declining trend within the entire investigating range of caffeine concentration. The sensor boasts of an unparalleled limit of detection value of 1.994 nM and works well in concentration range of 0-500 nM with a response time of 16 s. The impeccable sensor methodology adopted in this work combining fiber optic SPR with nanotechnology furnishes a novel perspective for caffeine determination in commercial foodstuffs and biological fluids.

  6. Bioactive materials for biomedical applications using sol-gel technology

    International Nuclear Information System (INIS)

    Gupta, Radha; Kumar, Ashok

    2008-01-01

    This review paper focuses on the sol-gel technology that has been applied in many of the potential research areas and highlights the importance of sol-gel technology for preparing bioactive materials for biomedical applications. The versatility of sol-gel chemistry enables us to manipulate the characteristics of material required for particular applications. Sol-gel derived materials have proved to be good biomaterials for coating films and for the construction of super-paramagnetic nanoparticles, bioactive glasses and fiberoptic applicators for various biomedical applications. The introduction of the sol-gel route in a conventional method of preparing implants improves the mechanical strength, biocompatibility and bioactivity of scaffolds and prevents corrosion of metallic implants. The use of organically modified silanes (ORMOSILS) yields flexible and bioactive materials for soft and hard tissue replacement. A novel approach of nitric-oxide-releasing sol-gels as antibacterial coatings for reducing the infection around orthopedic implants has also been discussed

  7. Aging of trivalent metal hydroxide/oxide gels in divalent metal salt ...

    Indian Academy of Sciences (India)

    Unknown

    3' gels do not form LDHs on aging in any of the divalent metal salts. In general, conditions .... values of I pH and II pH for all the systems investigated in this paper are given in ... spectra were obtained using a Nicolet Model Impact. 400D FTIR ...

  8. Physicochemical properties of manganese oxides obtained via the sol-gel method: The reduction of potassium permanganate by polyvinyl alcohol

    Science.gov (United States)

    Ivanets, A. I.; Prozorovich, V. G.; Krivoshapkina, E. F.; Kuznetsova, T. F.; Krivoshapkin, P. V.; Katsoshvili, L. L.

    2017-08-01

    Experimental data on the sol-gel synthesis of manganese oxides formed during the reduction of potassium permanganate by polyvinyl alcohol in an aqueous medium are presented. The physicochemical properties of the obtained manganese oxide systems that depend on the conditions of the synthesis are studied by means of DTA, XRD, SEM, and the low temperature adsorption-desorption of nitrogen. It is found that the obtained samples have a mesoporous structure and predominantly consist of double potassium-manganese oxide K2Mn4O8 with a tunnel structure and impurities of oxides such as α-MnO2, MnO, α-Mn2O3, and Mn5O8. It is shown that the proposed method of synthesis allows us to regulate the size and volume of mesopores and, to a lesser extent, the texture of the obtained oxides, which can be considered promising sorbents for the selective extraction of strontium and cesium ions from multicomponent aqueous solutions.

  9. Evaluation of tetraethoxysilane (TEOS) sol–gel coatings, modified with green synthesized zinc oxide nanoparticles for combating microfouling

    Energy Technology Data Exchange (ETDEWEB)

    Krupa, A. Nithya Deva; Vimala, R., E-mail: vimala.r@vit.ac.in

    2016-04-01

    Green synthesis of zinc oxide nanoparticles (ZnO-NPs) is gaining importance as an eco-friendly alternative to conventional methods due to its enormous applications. The present work reports the synthesis of ZnO-NPs using the endosperm of Cocos nucifera (coconut water) and the bio-molecules responsible for nanoparticle formation have been identified. The synthesized nanoparticles were characterized using UV–Visible spectroscopy (UV–Vis), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and Zeta potential measurement. The results obtained reveal that the synthesized nanoparticles are moderately stable with the size ranging from 20 to 80 nm. The bactericidal effect of the nanoparticles was proved by well diffusion assay and determination of minimum inhibitory concentration (MIC) against marine biofilm forming bacteria. Further the green synthesized ZnO-NPs were doped with TEOS sol–gels (TESGs) in order to assess their antimicrofouling capability. Different volumes of liquid sol–gels were coated on to 96-well microtitre plate and cured under various conditions. The optimum curing conditions were found to be temperature 60 °C, time 72 h and volume 200 μl. Antiadhesion test of the undoped (SG) and ZnO-NP doped TEOS sol–gel (ZNSG) coatings were evaluated using marine biofilm forming bacteria. ZNSG coatings exhibited highest biofilm inhibition (89.2%) represented by lowest OD value against Pseudomonasotitidis strain NV1. - Highlights: • The study reports low cost, and simple procedure for the synthesis of ZnO-NPs using coconut water. • XRD result shows the high crystalline nature of the synthesized ZnO-NPs. • TEM and zeta potential distribution confirms the nanostructure, stability of the synthesized ZnO-NPs. • ZnO-NPs doped with TEOS sol¬-gels (TESGs) exhibited excellent antimicrofouling activity.

  10. High-density carrier-accumulated and electrically stable oxide thin-film transistors from ion-gel gate dielectric.

    Science.gov (United States)

    Fujii, Mami N; Ishikawa, Yasuaki; Miwa, Kazumoto; Okada, Hiromi; Uraoka, Yukiharu; Ono, Shimpei

    2015-12-18

    The use of indium-gallium-zinc oxide (IGZO) has paved the way for high-resolution uniform displays or integrated circuits with transparent and flexible devices. However, achieving highly reliable devices that use IGZO for low-temperature processes remains a technological challenge. We propose the use of IGZO thin-film transistors (TFTs) with an ionic-liquid gate dielectric in order to achieve high-density carrier-accumulated IGZO TFTs with high reliability, and we discuss a distinctive mechanism for the degradation of this organic-inorganic hybrid device under long-term electrical stress. Our results demonstrated that an ionic liquid or gel gate dielectric provides highly reliable and low-voltage operation with IGZO TFTs. Furthermore, high-density carrier accumulation helps improve the TFT characteristics and reliability, and it is highly relevant to the electronic phase control of oxide materials and the degradation mechanism for organic-inorganic hybrid devices.

  11. Fabrication of ceramic oxide-coated SWNT composites by sol-gel process with a polymer glue

    Science.gov (United States)

    Zhang, Cheng; Gao, Lei; Chen, Yongming

    2011-09-01

    The functional copolymer bearing alkoxysilyl and pyrene groups, poly[3-(triethoxysilyl)propyl methacrylate]- co-[(1-pyrene-methyl) methacrylate] (TEPM13- co-PyMMA3), was synthesized via atom transfer radical polymerization. Attributing the π-π interaction of pyrene units with the walls of single-walled carbon nanotubes (SWNTs), this polymer could disperse and exfoliate SWNTs in different solvents through physical interaction as demonstrated by TEM, UV/Vis absorption, and FT-IR analysis. The alkoxysilyl groups functionalized SWNTs were reacted with different inorganic precursors via sol-gel reaction, and, as a results, silica, titania, and alumina were coated onto the surface of SWNTs, respectively via copolymers as a molecular glue. The nanocomposites of ceramic oxides/SWNTs were characterized by SEM analysis. Dependent upon the feed, the thickness of inorganic coating can be tuned easily. This study supplies a facile and general way to coat SWNTs with ceramic oxides without deteriorating the properties of pristine SWNTs.

  12. Study on the Preparation and Properties of Colored Iron Oxide Thin Films

    International Nuclear Information System (INIS)

    Zhao Xianhui; Li Changhong; Liu Qiuping; He Junjing; Wang Hai; Liang Song; Duan Yandong; Liu Su

    2013-01-01

    Colored iron oxide thin films were prepared using Sol-gel technique. The raw materials were tetraethyl orthosilicate (TEOS), etoh ehanol (EtOH), iron nitrate, and de-ionized water. Various properties were measured and analysed, including the colour of thin films, surface topography, UV-Visible spectra, corrosion resistance and hydrophobicity. To understand how these properties influenced the structural and optical properties of Fe 2 O 3 thin films, Scanning Electron Microscope (SEM), UV Spectrophotometer and other facilities were employed. Many parameters influence the performance of thin films, such as film layers, added H 2 O content, and the amount of polydimethylsiloxane (PDMS). When the volume ratio of TEOS, EtOH and H 2 O was 15: 13: 1, the quality of Fe(NO 3 ) 3 ·9H 2 O was 6g, and pH value was 3, reddish and uniform Fe 2 O 3 thin films with excellent properties were produced. Obtained thin films possessed corrosion resistance in hydrochloric acid with pH=l and the absorption edge wavelength was ∼350.2nm. Different H 2 O contents could result in different morphologies of Fe 2 O 3 nanoparticles. When 1.5 ml PDMS was added into the Sol, thin films possessed hydrophobiliry without dropping. Coating with different layers, thin films appeared different morphologies. Meanwhile, with the increment of film layers, the absorbance increased gradually.

  13. Thin copper oxide films prepared by ion beam sputtering with subsequent thermal oxidation: Application in chemiresistors

    Energy Technology Data Exchange (ETDEWEB)

    Horak, P., E-mail: phorak@ujf.cas.cz [Nuclear Physics Institute, Academy of Sciences of the Czech Republic, 250 68 Řež (Czech Republic); Bejsovec, V.; Vacik, J.; Lavrentiev, V. [Nuclear Physics Institute, Academy of Sciences of the Czech Republic, 250 68 Řež (Czech Republic); Vrnata, M. [Department of Physics and Measurements, The University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6 (Czech Republic); Kormunda, M. [Department of Physics, Jan Evangelista Purkyně University in Ústí nad Labem, České mládeže 8, 400 96 Ústí nad Labem (Czech Republic); Danis, S. [Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, 121 16 Prague 2 (Czech Republic)

    2016-12-15

    Highlights: • A rapid oxidation process of thin copper films. • Sheet resistance up to 10{sup 9} Ω/◊. • Mixed oxide phase at 200 °C with significant hydroxide presence. • Gas sensing response to 1000 ppm of hydrogen and methanol vapours. • Increased sensitivity with Pd and Au catalyst to hydrogen and methanol, respectively. - Abstract: Copper oxide films were prepared by thermal oxidation of thin Cu films deposited on substrates by ion beam sputtering. The subsequent oxidation was achieved in the temperature range of 200 °C–600 °C with time of treatment from 1 to 7 h (with a 1-h step) in a furnace open to air. At temperatures 250 °C–600 °C, the dominant phase formed was CuO, while at 200 °C mainly the Cu{sub 2}O phase was identified. However, the oxidation at 200 °C led to a more complicated composition − in the depth Cu{sub 2}O phase was observed, though in the near-surface layer the CuO dominant phase was found with a significant presence of Cu(OH){sub 2}. A limited amount of Cu{sub 2}O was also found in samples annealed at 600 °C. The sheet resistance R{sub S} of the as-deposited Cu sample was 2.22 Ω/□, after gradual annealing R{sub S} was measured in the range 2.64 MΩ/□–2.45 GΩ/□. The highest R{sub S} values were obtained after annealing at 300 °C and 350 °C, respectively. Oxygen depth distribution was studied using the {sup 16}O(α,α) nuclear reaction with the resonance at energy 3032 keV. It was confirmed that the higher oxidation degree of copper is located in the near-surface region. Preliminary tests of the copper oxide films as an active layer of a chemiresistor were also performed. Hydrogen and methanol vapours, with a concentration of 1000 ppm, were detected by the sensor at an operating temperature of 300 °C and 350 °C, respectively. The response of the sensors, pointed at the p-type conductivity, was improved by the addition of thin Pd or Au catalytic films to the oxidic film surface. Pd-covered films showed

  14. Effect of annealing temperature on the tribological behavior of ZnO films prepared by sol-gel method

    International Nuclear Information System (INIS)

    Lin Liyu; Kim, Dae-Eun

    2009-01-01

    The tribological behavior of zinc oxide (ZnO) films grown on glass and silicon (100) substrates by sol-gel method was investigated. Particularly, the as-coated films were post-annealed at different temperatures in air to investigate the effect of annealing temperature. Crystal structural and surface morphology of the films were measured by X-ray diffraction (XRD) and Atomic Force Microscopy (AFM). XRD patterns and AFM images indicated that the crystallinity and grain size of the films were enhanced and increased, respectively, with temperature. The tribological behavior of films was evaluated by sliding the ZnO films against a Si 3 N 4 ball under 0.5 gf normal load using a reciprocating pin-on-plate tribo-tester. The wear tracks of the films were measured by AFM to quantify the wear resistance of the films. The results showed that the wear resistance of the films could be improved by the annealing process. The wear resistance of the films generally increased with annealing temperature. Specifically, the wear resistance of the films was significantly improved when the annealing temperature was higher than 550 deg. C. The increase in the wear resistance is attributed to the increase in hardness and modulus of the film with annealing temperature

  15. Nanoencapsulation of Rose-Hip Oil Prevents Oil Oxidation and Allows Obtainment of Gel and Film Topical Formulations.

    Science.gov (United States)

    Contri, Renata V; Kulkamp-Guerreiro, Irene C; da Silva, Sheila Janine; Frank, Luiza A; Pohlmann, Adriana R; Guterres, Silvia S

    2016-08-01

    The rose-hip oil holds skin regenerating properties with applications in the dermatological and cosmetic area. Its nanoencapsulation might favor the oil stability and its incorporation into hydrophilic formulations, besides increasing the contact with the skin and prolonging its effect. The aim of the present investigation was to develop suitable rose-hip-oil-loaded nanocapsules, to verify the nanocapsule effect on the UV-induced oxidation of the oil and to obtain topical formulations by the incorporation of the nanocapsules into chitosan gel and film. The rose-hip oil (500 or 600 μL), polymer (Eudragit RS100®, 100 or 200 mg), and acetone (50 or 100 mL) contents were separately varied aiming to obtain an adequate size distribution. The results led to a combination of the factors acetone and oil. The developed formulation showed average diameter of 158 ± 6 nm with low polydispersity, pH of 5.8 ± 0.9, zeta potential of +9.8 ± 1.5 mV, rose-hip oil content of 54 ± 1 μL/mL and tendency to reversible creaming. No differences were observed in the nanocapsules properties after storage. The nanoencapsulation of rose-hip oil decreased the UVA and UVC oxidation of the oil. The chitosan gel and film containing rose-hip-oil-loaded nanocapsules showed suitable properties for cutaneous use. In conclusion, it was possible to successfully obtain rose-hip-oil-loaded nanocapsules and to confirm the nanocapsules effect in protecting the oil from the UV rays. The chitosan gel and film were considered interesting alternatives for incorporating the nanoencapsulated rose-hip oil, combining the advantages of the nanoparticles to the advantages of chitosan.

  16. Evaluation of the photocatalytic ability of a sol-gel-derived MgO-ZrO2 oxide material

    Directory of Open Access Journals (Sweden)

    Ciesielczyk Filip

    2017-02-01

    Full Text Available This paper deals with the synthesis and characterization of a novel group of potential photocatalysts, based on sol-gel-derived MgO-ZrO2 oxide material. The material was synthesized in a typical sol-gel system using organic precursors of magnesia and zirconia, ammonia as a promoter of hydrolysis and methanol as a solvent. All materials were thoroughly analyzed, including morphology and particle sizes, chemical composition, identification of characteristic functional groups, porous structure parameters and crystalline structure. The proposed methodology of synthesis resulted in obtaining pure MgO-ZrO2 oxide material with micrometric-sized particles and a relatively high surface area. The samples underwent an additional calcination process which led to the crystalline phase of zirconia being formed. The key element of the study was the evaluation of the effectiveness of decomposition of C.I. Basic Blue 9 dye. It was shown that the calcined materials exhibit both satisfactory adsorption and photocatalytic activity with respect to the decomposition of a selected model organic impurity. Total dye removal varied in the range of 50-70%, and was strongly dependent on process parameters such as quantity of photocatalyst, time of irradiation, and the addition of promoters.

  17. Transition metal-free oxidation of benzylic alcohols to carbonyl compounds by hydrogen peroxide in the presence of acidic silica gel

    Directory of Open Access Journals (Sweden)

    Hossein Ghafuri

    2015-01-01

    Full Text Available Oxidation of alcohols to carbonyl compounds has become an important issue in the process industry as well as many other applications. In this method, various benzylic alcohols were successfully converted to corresponding aldehydes and ketones under transition metal-free condition using hydrogen peroxide in the presence of some amount of catalytic acidic silica gel. Silica gel is inexpensive and available. One of the most important features of this method is its short reaction time.

  18. Electrochemical properties of the hexacyanoferrate(II)–ruthenium(III) complex immobilized on silica gel surface chemically modified with zirconium(IV) oxide

    International Nuclear Information System (INIS)

    Panice, Lucimara B.; Oliveira, Elisangela A. de; Filho, Ricardo A.D. Molin; Oliveira, Daniela P. de; Lazarin, Angélica M.; Andreotti, Elza I.S.; Sernaglia, Rosana L.; Gushikem, Yoshitaka

    2014-01-01

    Highlights: • The cyano-bridged mixed valence ruthenium composite material was synthesized. • This newly synthesized compound was incorporated into a carbon paste electrode. • The electrode did not show significant changes in response after six months of use. • The modified electrode is very stable and reproducible. • The electrode sensor was successfully applied for ascorbic acid determination. - Abstract: The chemically modified silica gel with zirconium(IV) oxide was used to immobilize the [Fe(CN) 6 ] 4− complex ion initially. The reaction of this material with [Ru(edta)H 2 O] − complex ion formed the immobilized cyano-bridged mixed valence ruthenium complex, (≡Zr) 5 [(edta)RuNCFe(CN) 5 ]. This material was incorporated into a carbon paste electrode and, its electrochemical properties were investigated. However, for an ascorbic acid solution, an enhancement of the anodic peak current was detected due to electrocatalytic oxidation. The electrode presented the same response for at least 150 successive measurements, with a good repeatability. The modified electrode is very stable and reproducible. The sensor was applied for ascorbic acid determination in pharmaceutical preparation with success

  19. Photocatalysis of zinc oxide nanotip array/titanium oxide film heterojunction prepared by aqueous solution deposition

    Science.gov (United States)

    Lee, Ming-Kwei; Lee, Bo-Wei; Kao, Chen-Yu

    2017-05-01

    A TiO2 film was prepared on indium tin oxide (ITO)/glass by aqueous solution deposition (ASD) with precursors of ammonium hexafluoro-titanate and boric acid at 40 °C. The photocatalysis of annealed TiO2 film increases with increasing growth time and decreases with increasing growth times longer than 60 min. A ZnO nanotip array was prepared on ZnO seed layer/TiO2 film/glass by aqueous solution deposition with precursors of zinc nitrate and ammonium hydroxide at 70 °C. The photocatalysis of ASD-ZnO/ASD-TiO2 film/ITO glass can be better than that of P25.

  20. X-ray line profile analysis of BaTiO3 thin film prepared by sol-gel deposition

    Science.gov (United States)

    Ooi, Zeen Vee; Saif, Ala'eddin A.; Wahab, Yufridin; Jamal, Zul Azhar Zahid

    2017-04-01

    Barium titanate (BaTiO3) thin film was prepared using sol-gel method and spun-coated on SiO2/Si substrate. The phase and crystallinity of the synthesized film were identified using X-ray diffractometer (XRD), which scanned at the range of 20° to 60°. The phase and lattice parameters of the fabricated film were extracted from the recorded XRD patterns using lattice geometry equations. The crystallite size and lattice strain were determined using X-ray line profile analysis (XLPA) with various approaches. The Scherrer equation was applied to the perovskite peaks of the film to explore the size contribution on the peak broadening. Meanwhile, the Williamson-Hall and size-strain plot (SSP) methods were used to review two main independent contributions, i.e. crystallite sizes and lattice strain, on the X-ray line broadening. From the analysis, it is found that Scherrer method gives smallest crystallite size value by ignoring the strain-induced broadening effect. On the other hand, Williamson-Hall and SSP graphs revealed the existence of the lattice strain within the film, which contributes to the broadening in the Bragg peak. The results that analyzed via both techniques show a linear trend with all data points fitted. However, result obtained from SSP method gives better settlement due to the best fit of the data.

  1. Preparation and characterization of multilayer mesoporous γ-alumina membrane obtained via sol-gel using new precursors

    Directory of Open Access Journals (Sweden)

    Tafrishi R.

    2015-12-01

    Full Text Available In this paper, a mesoporous γ-alumina membrane coated on a macroporous α-alumina support via sol-gel method has been reported. A crack-free γ-alumina membrane was obtained by adding PVA to the alumina solution and optimum parameters of roughness, temperature and porosity were achieved. The support was dip-coated in different solutions using two new different solvents with different particle size distributions. Using these two solvents led to the uniform distribution of pore size in the final membrane. The alumina sols showed particle size distributions in the range of 20 to 55 nm which was measured by a DLS Zeta Sizer. X-ray diffraction technique, atomic force microscopy and scanning electron microscopy were used to characterize the membrane layer. XRD and DTA data for the γ-alumina membrane showed its thermal stability up to around 600 °C. The thickness of the mesoporous γ-alumina membrane was about 4 μm with 16 nm of surface roughness and 5 nm pore size. The resultant crack-free mesoporous membrane shows that the membrane preparation procedure was optimum. In this work, it has been investigated the performance of γ-alumina membranes for single gas permeation and separation of binary gas mixtures.

  2. Sol-gel synthesized of nanocomposite palladium-alumina ceramic membrane for H{sub 2} permeability: Preparation and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, A.L.; Mustafa, N.N.N. [School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, Seri Ampangan, 14300 Nibong Tebal, Penang (Malaysia)

    2007-08-15

    Palladium-alumina membrane with mesopore and narrow pore size distribution was prepared by the sol-gel method. Effect of the finely dispersed metal on the microstructure and the characteristic properties of the palladium-alumina membrane were investigated. Observations were made on membrane weight loss, morphology, pore structure, pore size, surface area, pore surface fractal and membrane's crystal structure. Autosorb analysis, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) analysis were employed in the membrane characterization. Autosorb analysis found that, BET surface area decreased and pore size of the membrane increased with the increasing of calcinations temperature (500-1100{sup o}C) and with the increasing of palladium amount in the membrane. FTIR and TG/DTA analysis show that the suitable temperature for calcinations of palladium-alumina membrane is at 700{sup o}C. Palladium metals are highly dispersed at calcinations temperature of 700{sup o}C as observed by TEM analysis. The fine crystallinity of the palladium and {gamma}-alumina phase was obtained after calcined at 700{sup o}C. The SEM morphology shows a smooth and free crack layer of palladium-alumina membrane after repeating the process of dipping, drying and calcinations at temperature of 700{sup o}C. The membrane also successfully coated with a good adhesion on support. The thickness of the final membrane layer was estimated as 9{mu} m. (author)

  3. Effects of Calcination Temperature on Preparation of Boron-Doped TiO2 by Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    Wenjie Zhang

    2012-01-01

    Full Text Available Boron-doped TiO2 photocatalyst was prepared by a modified sol-gel method. Being calcinated at temperatures from 300°C to 600°C, all the 3% B-TiO2 samples presented anatase TiO2 phase, and TiO2 crystallite sizes were calculated to be 7.6, 10.3, 13.6, and 27.3 nm, respectively. The samples were composed of irregular particles with rough surfaces in the size range within 3 μm. Ti atoms were in an octahedron skeleton and existed mainly in the form of Ti4+, while the Ti-O-B structure was the main boron existing form in the 3% B-TiO2 sample. When calcination temperature increased from 300°C to 600°C, specific surface area decreased sharply from 205.6 m2/g to 31.8 m2/g. The average pore diameter was 10.53 nm with accumulative pore volume of 0.244 mL/g for the 3% B-TiO2 sample calcinated at 400°C, which performed optimal photocatalytic degradation activity. After 90 min of UV-light irradiation, degradation rate of methyl orange was 96.7% on the optimized photocatalyst.

  4. Sol–gel followed by urea–acetone spherodization for preparation of lithium titanate ceramics pebbles and preliminary characterization

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, S.K., E-mail: sk.sinha@bitmesra.ac.in [Department of Physics, Birla Institute of Technology, Patna 800014 (India); Yadav, S. [Department of Physics, Birla Institute of Technology, Patna 800014 (India); Raole, P.M. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

    2016-12-15

    Lithium titanate ceramics pebbles were prepared by chemical method of sol. gel followed by urea-aceton spherodization technique. Lithium titanate having monoclinic phase was obtained. Laser flash method was used to study thermal conductivity and diffusivity of the ceramics. At near 472 K the average value of diffusivity was around 0.0052 cm{sup 2} s{sup −1} while the specific heat capacity was 3101.3 J kg{sup −1} K{sup −1} while the same two parameters had values of 0.0041 cm{sup 2} s{sup −1} and 3894.4 J kg{sup −1} K{sup −1} at a temperature 1050 K. The crush strength of pebble was measured on Universal Testing Machine (UTM) and was found as 37.08 N. The density was measured and found to be 2.8 g/cc (81.63% of TD of value 3.43 g/cc).

  5. Enhanced photoelectrochemical performance of Ti-doped hematite thin films prepared by the sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Lian Xiaojuan; Yang Xin; Liu Shangjun; Xu Ying; Jiang Chunping; Chen Jinwei [College of Materials Science and Engineering, Sichuan University, No.24 South Section 1, Yihuan Road, Chengdu 610065 (China); Wang Ruilin, E-mail: rlwang26@yahoo.com.cn [College of Materials Science and Engineering, Sichuan University, No.24 South Section 1, Yihuan Road, Chengdu 610065 (China)

    2012-01-15

    Ti-doped {alpha}-Fe{sub 2}O{sub 3} thin films were successfully prepared on FTO substrates by the sol-gel route. Hematite film was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS). The XRD data showed {alpha}-Fe{sub 2}O{sub 3} had a preferred (1 1 0) orientation which belonged to the rhombohedral system. Interestingly, the grains turned into worm-like shape after annealed at high temperature. The IPCE could reach 32.6% at 400 nm without any additional potential vs. SCE. Titanium in the lattice can affect the photo electro chemical performance positively by increasing the conductivity of the thin film. So the excited electrons and holes could live longer, rather than recombining with each other rapidly as undoped hematite. And the efficient carrier density on the Ti-doped anode surface was higher than the undoped anode, which contribute to the well PEC performance.

  6. Indium tin oxide films prepared via wet chemical route

    International Nuclear Information System (INIS)

    Legnani, C.; Lima, S.A.M.; Oliveira, H.H.S.; Quirino, W.G.; Machado, R.; Santos, R.M.B.; Davolos, M.R.; Achete, C.A.; Cremona, M.

    2007-01-01

    In this work, indium tin oxide (ITO) films were prepared using a wet chemical route, the Pechini method. This consists of a polyesterification reaction between an α-hydroxicarboxylate complex (indium citrate and tin citrate) with a polyalcohol (ethylene glycol) followed by a post annealing at 500 deg. C. A 10 at.% of doping of Sn 4+ ions into an In 2 O 3 matrix was successfully achieved through this method. In order to characterize the structure, the morphology as well as the optical and electrical properties of the produced ITO films, they were analyzed using different experimental techniques. The obtained films are highly transparent, exhibiting transmittance of about 85% at 550 nm. They are crystalline with a preferred orientation of [222]. Microscopy discloses that the films are composed of grains of 30 nm average size and 0.63 nm RMS roughness. The films' measured resistivity, mobility and charge carrier concentration were 5.8 x 10 -3 Ω cm, 2.9 cm 2 /V s and - 3.5 x 10 20 /cm 3 , respectively. While the low mobility value can be related to the small grain size, the charge carrier concentration value can be explained in terms of the high oxygen concentration level resulting from the thermal treatment process performed in air. The experimental conditions are being refined to improve the electrical characteristics of the films while good optical, chemical, structural and morphological qualities already achieved are maintained

  7. Methanol oxidation at platinized copper particles prepared by galvanic replacement

    Directory of Open Access Journals (Sweden)

    Ioanna Mintsouli

    2016-04-01

    Full Text Available Bimetallic Pt-Cu particles have been prepared by galvanic replacement of Cu precursor nanoparticles, upon the treatment of the latter with a chloro-platinate acidic solution. The resulting particles, typically a few tens of nm large, were supported on high surface area carbon (Vulcan® XC–72R, Cabot and tested as electrodes. Surface electrochemistry in deaerated acid solutions was similar to that of pure Pt, indicating the existence of a Pt shell (hence the particles are denoted as Pt(Cu. Pt(Cu/C supported catalysts exhibit superior carbon monoxide and methanol oxidation activity with respect to their Pt/C analogues when compared on a per electroactive surface area basis, due to the modification of Pt activity by Cu residing in the particle core. However, as a result of large particle size and agglomeration phenomena, Pt(Cu/C are still inferior to Pt/C when compared on a mass specific activity basis.

  8. Preparation and characterization of carbon/nickel oxide nanocomposite coatings for solar absorber applications

    CSIR Research Space (South Africa)

    Roro, Kittessa T

    2012-04-01

    Full Text Available Nanocomposite materials have wide range of applications in solar energy conversion. In this work, C/NiO nanocomposite solar energy absorbing surfaces were prepared using sol-gel synthesis and deposited on aluminium substrates using a spin coater...

  9. Nonhydrolytic sol-gel approach to facile creation of surface-bonded zirconia organic-inorganic hybrid coatings for sample preparation. Ι. Capillary microextraction of catecholamine neurotransmitters.

    Science.gov (United States)

    Alhendal, Abdullah; Mengis, Stephanie; Matthews, Jacob; Malik, Abdul

    2016-10-14

    Nonhydrolytic sol-gel (NHSG) route was used for the creation of novel zirconia-polypropylene oxide (ZrO 2 -PPO) sol-gel hybrid sorbents in the form of surface coatings for the extraction and preconcentration of catecholamine neurotransmitters and molecules structurally related to their deaminated metabolites. In comparison to other sorbents made of inorganic transition metal oxides, the presented hybrid organic-inorganic sorbents facilitated reversible sorption properties that allowed for efficient desorption of the extracted analytes by LC-MS compatible mobile phases. The presented sol-gel hybrid sorbents effectively overcame the major drawbacks of traditional silica- or polymer-based sorbents by providing superior pH stability (pH range: 0-14), and a variety of intermolecular interactions. Nonaqueous sol-gel treatment of PPO with ZrCl 4 was employed for the derivatization of the terminal hydroxyl groups on PPO, providing zirconium trichloride-containing end groups characterized by enhanced sol-gel reactivity. NHSG ZrO 2 -PPO sorbent provided excellent microextraction performance for catecholamines, low detection limits (5.6-9.6pM), high run-to-run reproducibility (RSD 0.6-5.1%), high desorption efficiency (95.0-99.5%) and high enrichment factors (∼1480-2650) for dopamine and epinephrine, respectively, extracted from synthetic urine samples. The presented sol-gel sorbents provided effective alternative to conventional extraction media providing unique physicochemical characteristics and excellent extraction capability. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. TEMPO-oxidized Konjac glucomannan as appliance for the preparation of hard capsules

    NARCIS (Netherlands)

    Chen, Yuying; Zhao, Huiying; Liu, Xianwu; Li, Zusen; Liu, Bin; Wu, Jiande; Shi, Mengxuan; Norde, Willem; Li, Yuan

    2016-01-01

    TEMPO-oxidized Konjac glucomannan (OKGM) was developed as new material for preparing vegetarian hard capsules. OKGM of different degrees of oxidation: DO30%, DO50%, and DO80% were prepared to select optimum DO for capsule formation. FT-IR results proved that the primary alcohol groups on KGM were

  11. Studies of the effect of irradiation in a nuclear reactor, of targets containing Mo used for the preparation of 99Mo gel, material that constitutes the 99Mo - 99mTc generators

    International Nuclear Information System (INIS)

    Nieto, Renata Correa

    2004-01-01

    The most used radioisotope in Nuclear Medicine is 99m Tc, obtained in the 99 Mo - 99m Tc generator form. 99 Mo can be produced by several nuclear reactions in Cyclotron and Reactor. The production in Cyclotron is not technically and commercially feasible. The production in Nuclear Reactor can be made in two ways: 235 U fission and 99 Mo (n,γ) 99 Mo reaction. A project aiming the production of 99 Mo by activation of Mo is under way at IPEN, producing a gel type MoZr generator. There are two ways of preparing the gel and the generators: by irradiating MoO 3 and preparing the gel or by the preparation of the gel and further irradiation. This work consists in the study of the irradiation effects in several targets containing Mo for the production of 99 Mo by the 98 Mo (n,γ) 99 Mo reaction and further preparation of the gel for use as a gel type 99 Mo - 99m Tc generator. Three rinds of gel were studied: zirconium, titanium and cerium molybdate, and their morphology, infrared structure and elution yield of 99m Tc were analysed. The best results were achieved with the generators prepared with MoZr post formed gel, with amorphous structure and better elution yields. The pre formed gel induced crystallinity and worst performance of the generators. (author)

  12. Colloidal sol-gel synthesis of oxides: application to the precursors of nuclear fuels

    International Nuclear Information System (INIS)

    Gossard, Alban

    2014-01-01

    One of the main objectives for the future nuclear fuel cycle is the recycling of the minor actinides. Different options are considered: their integration into a new fuel for a prospect of a closed fuel cycle or their transmutation in order to significantly decrease the long-term radiotoxicity of ultimate wastes. In both cases, the synthesis of new advanced materials integrating the actinides jointly is required. Sol-gel processes allow the organization of the material at the colloidal scale or the insertion of controlled porosity using 'templates'. Furthermore, the possibility to work in a 'wet environment' prevents the formation of pulverulent powders which are contaminant in the case of materials incorporating radioactive elements. The main purpose of this work is to demonstrate the adaptability of this route to the nuclear field. Firstly, a methodology of synthesis from a colloidal sol-gel route was set up on a non-radioactive zirconium-based system in order to characterize and understand of the different mechanisms of this synthesis. Then, studies on shaping, including insertion of porosity, were performed. Zirconia monoliths have been obtained thanks to a coupling between a colloidal sol-gel process and the formation of an emulsion stabilized by clusters of solid particles. Finally, a transposition of this work to an uranium-based system was introduced, pointing out different promising perspectives specially concerning the possibilities of shaping of the final material. (author) [fr

  13. Gelatin Template Synthesis of Aluminum Oxide and/or Silicon Oxide Containing Micro/Mesopores Using the Proteic Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    Amanda Sayure Kasuya de Oliveira

    2017-01-01

    Full Text Available Aluminum oxide and/or silicon oxide-based supports were synthesized by proteic sol-gel method. The characterization was performed through the analysis of TG, XRD, FTIR, SEM, and N2 physisorption. The XRD diffractograms showed an amorphous material profile. TG results indicate the total liberation of the organic and inorganic material in the calcination temperature used, occurring in different mass loss range. This piece of information was reaffirmed by the FTIR spectra, which presented characteristic bands of gelatin structure before calcinations which disappear in the spectrum of the solid after calcinations, indicating the loss of organic matter from gelatin after heat treatment. The spectra exhibited M-O stretching vibration at low wavenumbers after calcinations related to metal oxides. The acquired images by SEM suggest the obtaining of a highly porous material with very different characteristics depending on the composition of the support. The N2 isotherms indicate the presence of a micro/mesoporous oxide with interesting textural properties, particularly for the supports containing aluminum and silicon oxide. The ethanol dehydration results showed greater selectivity to diethyl ether compared to ethylene. From the reaction data, the following order of acid strength was obtained: 2Si-Al > Si-2Al > Si-Al > Al, which is related to the Si-Al ratio.

  14. Preparation of reduced graphene oxide/gelatin composite films with reinforced mechanical strength

    International Nuclear Information System (INIS)

    Wang, Wenchao; Wang, Zhipeng; Liu, Yu; Li, Nan; Wang, Wei; Gao, Jianping

    2012-01-01

    Highlights: ► We used and compared different proportion of gelatin and chitosan as reducing agents. ► The mechanical properties of the films are investigated, especially the wet films. ► The cell toxicity of the composite films as biomaterial is carried out. ► The water absorption capabilities of the composite films also studied. -- Abstract: Graphene oxide (GO) was reduced by chitosan/gelatin solution and added to gelatin (Gel) to fabricate reduced graphene oxide/gelatin (RGO/Gel) films by a solvent-casting method using genipin as cross-linking agent. The structure and properties of the films were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA) and UV–vis spectroscopy. The addition of RGO increased the tensile strength of the RGO/Gel films in both dry and wet states, but decreased their elongation at break. The incorperation of RGO also decreased the swelling ability of the films in water. Cell cultures were carried out in order to test the cytotoxicity of the films. The cells grew and reproduced well on the RGO/Gel films, indicating that the addition of RGO has no negative effect on the compatibility of the gelatin. Therefore, the reduced graphene oxide/gelatin composite is a promising biomaterial with excellent mechanical properties and good cell compatibility.

  15. Therapeutic Potential of Human Adipose-Derived Stem/Stromal Cell Microspheroids Prepared by Three-Dimensional Culture in Non-Cross-Linked Hyaluronic Acid Gel.

    Science.gov (United States)

    Mineda, Kazuhide; Feng, Jingwei; Ishimine, Hisako; Takada, Hitomi; Doi, Kentaro; Kuno, Shinichiro; Kinoshita, Kahori; Kanayama, Koji; Kato, Harunosuke; Mashiko, Takanobu; Hashimoto, Ichiro; Nakanishi, Hideki; Kurisaki, Akira; Yoshimura, Kotaro

    2015-12-01

    Three-dimensional culture of mesenchymal stem/stromal cells for spheroid formation is known to enhance their therapeutic potential for regenerative medicine. Spheroids were prepared by culturing human adipose-derived stem/stromal cells (hASCs) in a non-cross-linked hyaluronic acid (HA) gel and compared with dissociated hASCs and hASC spheroids prepared using a nonadherent dish. Preliminary experiments indicated that a 4% HA gel was the most appropriate for forming hASC spheroids with a relatively consistent size (20-50 µm) within 48 hours. Prepared spheroids were positive for pluripotency markers (NANOG, OCT3/4, and SOX-2), and 40% of the cells were SSEA-3-positive, a marker of the multilineage differentiating stress enduring or Muse cell. In contrast with dissociated ASCs, increased secretion of cytokines such as hepatocyte growth factor was detected in ASC spheroids cultured under hypoxia. On microarray ASC spheroids showed upregulation of some pluripotency markers and downregulation of genes related to the mitotic cell cycle. After ischemia-reperfusion injury to the fat pad in SCID mice, local injection of hASC spheroids promoted tissue repair and reduced the final atrophy (1.6%) compared with that of dissociated hASCs (14.3%) or phosphate-buffered saline (20.3%). Part of the administered hASCs differentiated into vascular endothelial cells. ASC spheroids prepared in a HA gel contain undifferentiated cells with therapeutic potential to promote angiogenesis and tissue regeneration after damage. This study shows the therapeutic value of human adipose-derived stem cell spheroids prepared in hyarulonic acid gel. The spheroids have various benefits as an injectable cellular product and show therapeutic potential to the stem cell-depleted conditions such as diabetic chronic skin ulcer. ©AlphaMed Press.

  16. Thin copper oxide films prepared by ion beam sputtering with subsequent thermal oxidation: Application in chemiresistors

    Science.gov (United States)

    Horak, P.; Bejsovec, V.; Vacik, J.; Lavrentiev, V.; Vrnata, M.; Kormunda, M.; Danis, S.

    2016-12-01

    Copper oxide films were prepared by thermal oxidation of thin Cu films deposited on substrates by ion beam sputtering. The subsequent oxidation was achieved in the temperature range of 200 °C-600 °C with time of treatment from 1 to 7 h (with a 1-h step) in a furnace open to air. At temperatures 250 °C-600 °C, the dominant phase formed was CuO, while at 200 °C mainly the Cu2O phase was identified. However, the oxidation at 200 °C led to a more complicated composition - in the depth Cu2O phase was observed, though in the near-surface layer the CuO dominant phase was found with a significant presence of Cu(OH)2. A limited amount of Cu2O was also found in samples annealed at 600 °C. The sheet resistance RS of the as-deposited Cu sample was 2.22 Ω/□, after gradual annealing RS was measured in the range 2.64 MΩ/□-2.45 GΩ/□. The highest RS values were obtained after annealing at 300 °C and 350 °C, respectively. Oxygen depth distribution was studied using the 16O(α,α) nuclear reaction with the resonance at energy 3032 keV. It was confirmed that the higher oxidation degree of copper is located in the near-surface region. Preliminary tests of the copper oxide films as an active layer of a chemiresistor were also performed. Hydrogen and methanol vapours, with a concentration of 1000 ppm, were detected by the sensor at an operating temperature of 300 °C and 350 °C, respectively. The response of the sensors, pointed at the p-type conductivity, was improved by the addition of thin Pd or Au catalytic films to the oxidic film surface. Pd-covered films showed an increased response to hydrogen at 300 °C, while Au-covered films were more sensitive to methanol vapours at 350 °C.

  17. PREPARATION OF NICKEL - COBALT SPINEL OXIDES NixCO3 ...

    African Journals Online (AJOL)

    degree of crystallinity give rise to reversible nickel incorporation. Pellets ... are of interest in solid oxide fuel cell and this is one of the features which make them attractive ... oxide system can only be obtained in a limited composition extent.

  18. Preparation and investigations of thermal properties of copper oxide ...

    Indian Academy of Sciences (India)

    The effects of copper oxide, aluminium oxide and graphite on the thermal and structural properties of the organic ... solar energy, and heat regulation of electronics, biomedical ..... We gratefully acknowledge the financial support provided by.

  19. In vitro study of the role of thrombin in platelet rich plasma (PRP) preparation: utility for gel formation and impact in growth factors release.

    Science.gov (United States)

    Huber, Stephany Cares; Cunha Júnior, José Luiz Rosenberis; Montalvão, Silmara; da Silva, Letícia Queiroz; Paffaro, Aline Urban; da Silva, Francesca Aparecida Ramos; Rodrigues, Bruno Lima; Lana, José Fabio Santos Duarte; Annichino-Bizzacchi, Joyce Maria

    2016-01-01

    The use of PRP has been studied for different fields, with promising results in regenerative medicine. Until now, there is no study in the literature evaluating thrombin levels in serum, used as autologous thrombin preparation. Therefore, in the present study we evaluated the role played by different thrombin concentrations in PRP and the impact in the release of growth factors. Also, different activators for PRP gel formation were evaluated. Thrombin levels were measured in different autologous preparations: serum, L-PRP (PRP rich in leukocytes) and T-PRP (thrombin produced through PRP added calcium gluconate). L-PRP was prepared according to the literature, with platelets and leukocytes being quantified. The effect of autologous thrombin associated or not with calcium in PRP gel was determined by measuring the time of gel formation. The relationship between thrombin concentration and release of growth factors was determined by growth factors (PDGF-AA, VEGF and EGF) multiplex analysis. A similar concentration of thrombin was observed in serum, L-PRP and T-PRP (8.13 nM, 8.63 nM and 7.56 nM, respectively) with a high variation between individuals (CV%: 35.07, 43 and 58.42, respectively). T-PRP and serum with calcium chloride showed similar results in time to promote gel formation. The increase of thrombin concentrations (2.66, 8 and 24 nM) did not promote an increase in growth factor release. The technique of using serum as a thrombin source proved to be the most efficient and reproducible for promoting PRP gel formation, with some advantages when compared to other activation methods, as this technique is easier and quicker with no need of consuming part of PRP. Noteworthy, PRP activation using different thrombin concentrations did not promote a higher release of growth factors, appearing not to be necessary when PRP is used as a suspension.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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