Preparation of Silicon Dioxide Fiber via Sol-Gel Process

2008 ◽  
Vol 368-372 ◽  
pp. 794-796
Author(s):  
Xiao Hui Wang ◽  
Xiao Ping Liang ◽  
Shao Bo Xin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hydrochloric Acid ◽  
Silicon Dioxide ◽  
Sol Gel ◽  
Tetraethyl Orthosilicate ◽  
Molar Ratio ◽  
Sol Gel Process ◽  
Different Temperatures ◽  
Scanning Electron

Silicon dioxide gel fibers were prepared by hydrolysis reaction of tetraethyl orthosilicate (TEOS). TEOS was used as basic materials, anhydrous ethanol (EtOH) as solvent and hydrochloric acid (HCl) as the catalyst. The best proportion of the chosen materials (TEOS, EtOH, H2O and HCl) was 1:1:1.5:0.03(molar ratio).Gel fibers were investigated by thermogravimetry (TG). Silicon dioxide fibers were obtained by treating the gel fibers at different temperatures. The calcined fibers were characterized by scanning electron microscopy (SEM). The optimal sintering schedule was obtained. Silicon dioxide fiber dried at 200°C for 1 hour then calcined at 800°C for 3 hours was the best.

Antitumoral drug loaded in TEOS nanoparticles

2012 ◽  
Vol 1498 ◽  
pp. 9-14 ◽  
Author(s):  
Ana Paula V. Araújo ◽  
Claure N. Lunardi ◽  
Anderson J. Gomes
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Slow Release ◽  
Sol Gel ◽  
Aqueous Media ◽  
Tetraethyl Orthosilicate ◽  
Mean Diameter ◽  
Immunomodulating Drug ◽  
Distribution Studies ◽  
Scanning Electron

ABSTRACTMethotrexate (MTX), is a potent immunomodulating drug and widely used in the treatment of cancer, psoriasis and others disease. Despite its efficacy, the use of MTX is greatly limited due to its toxicity. To solve this problem, we prepared nanoparticles of tetraethyl orthosilicate (NP-TEOS) containing the compound methotrexate (MTX), by the sol-gel method. This drug delivery system (DDS) showed a loading efficiency of 39.7%. Size distribution studies were performed with dynamic light scattering and scanning electron microscopy revealing that these particles were spherical in shape, with a mean diameter between 140-430 nm and a low polydispersity (0.12 – 0.26). Also the particles displayed a low tendency toward aggregation which was confirmed by the low zeta potential -61.4 mV. Profile release showed a slow release loaded with MTX (PBS buffer pH = 7.4). The slow release can be attributed to the low porosity of the NP-TEOS and the extremely low diffusivity of MTX in aqueous media. B16-F10 cells were used to assay the toxicity and uptake of NP-TEOS showing to be nontoxic without MTX making a good candidate for DDS.

scholarly journals Porosity in Polysilsesquioxane Xerogels

1999 ◽  
Vol 576 ◽  
Author(s):  
Brigitta M. Baugher ◽  
Duane A. Schneider ◽  
Douglas A. Loy ◽  
Kamyar Rahimian
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Pore Structure ◽  
Convenient Method ◽  
Sol Gel ◽  
Monomer Concentration ◽  
Inorganic Materials ◽  
Sol Gel Process ◽  
Very High ◽  
Scanning Electron

ABSTRACTPolymerization of organotrialkoxysilanes is a convenient method for introducing organic functionality into hybrid organic-inorganic materials. However, not much is known about the effects of the organic substituent on the porosity of the resulting xerogels. In this study, we prepared a series of polysilsesquioxane xerogels from organotrialkoxysilanes, RSi(OR′)3, with different organic groups (R = H, Me, Et, dodecyl, hexadecyl, octadecyl, vinyl, chloromethyl, cyanoethyl). Polymerizations of the monomers were carried out under a variety of conditions, varying monomer concentration, type of catalyst, and alkoxide substituent. The effect of the organic substituent on the sol-gel process was often dramatic. In many cases, gels were formed only at very high monomer concentration and/or with only one type of catalyst. All of the gels were processed as xerogels and characterized by scanning electron microscopy and nitrogen sorption porosimetry to evaluate their pore structure.

Research of Rough Structure of Superhydrophobic Film

2011 ◽  
Vol 287-290 ◽  
pp. 253-256
Author(s):  
Zhan Shen Zheng ◽  
Rui Jiao Li ◽  
Pei Qi Yan ◽  
Rong Yang ◽  
Peng Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Scanning Electron

Superhydrophobic film was fabricated mainly by ethyl silicate (TEOS) and ethanol (EtOH) using sol-gel method. SiO2 gel and samples coated with SiO2 sol were calcined at different temperatures, and their morphology and composition were studied using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The results indicate that increasing calcining temperature appropriately improved the bond of nanoparticles of film successfully. Furthermore, there were only amorphous SiO2 and hydroxyl existing in the calcined film which would be benefit for the further modification.

scholarly journals A STUDY OF THE SYNTHESIS OF HYBRID ORGANOSILICATE NANOTUBES

2010 ◽  
Vol 5 (2) ◽  
pp. 83-86
Author(s):  
Eko Sri Kunarti ◽  
Grainne M Moran
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Room Temperature ◽  
Sol Gel ◽  
Tetraethyl Orthosilicate ◽  
Physical Characteristics ◽  
Ammonium Tartrate ◽  
Tube Forming ◽  
Controlled Hydrolysis ◽  
Scanning Electron

Hybrid organosilicate nanotubes have been prepared by sol-gel chemistry, using crystalline ammonium tartrate as the tube-forming template. The nanotubes were prepared by controlled hydrolysis and co-condensation of tetraethyl orthosilicate (TEOS) and methyltriethoxysilane (MTES) at room temperature. The synthetic conditions have been systematically studied. The physical characteristics of the materials were examined by scanning electron microscopy (SEM) and the aging times of the tubes due to slow post-gelation condensation reactions was investigated. The morphology and microstructure of the nanotubes are greatly influenced by the synthetic conditions.   Keywords: organosilicate, nanotube, ammonium tartrate crystals.

Surface Morphology and the Adsorptive Behavior of Coconut Active Carbon

2013 ◽  
Vol 690-693 ◽  
pp. 1029-1032
Author(s):  
Xiao Qiang Li ◽  
Li Juan Lan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hydrochloric Acid ◽  
Active Carbon ◽  
Adsorption Process ◽  
Hydrochloric Acid Concentration ◽  
Impregnation Method ◽  
Adsorption Experiment ◽  
Adsorptive Behavior ◽  
Scanning Electron

Active carbon modified by hydrochloric acid was prepared with impregnation method. The synthesized material was characterized by scanning electron microscopy. It was proved that plenty of pores with diameter of about 5-10μm were exist on the surface of active carbon. The adsorption process with toluene was performed over the modified active carbon to investigate the adsorptive efficiency. For comparison, other porous materials were also performed the adsorption experiment. The results showed that active carbon modified by hydrochloric acid has high adsorptive efficiency for toluene. The results proved that adsorptive performance of active carbon increased with the hydrochloric acid concentration.

scholarly journals Structural and optical properties of SnO2–Al2O3 nanocomposite synthesized via sol-gel route

2015 ◽  
Vol 33 (4) ◽  
pp. 714-718 ◽  
Author(s):  
Neeraj K. Mishra ◽  
Chaitnaya Kumar ◽  
Amit Kumar ◽  
Manish Kumar ◽  
Pratibha Chaudhary ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Properties ◽  
Sol Gel ◽  
Physical Interaction ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Sensing Applications ◽  
Scanning Electron

AbstractA nanocomposite of 0.5SnO2–0.5Al2O3 has been synthesized using a sol-gel route. Structural and optical properties of the nanocomposite have been discussed in detail. Powder X-ray diffraction and scanning electron microscopy with energy-dispersive X-ray diffraction spectroscopy confirm the phase purity and the particle size of the 0.5SnO2–0.5Al2O3 nanocomposite (13 to 15 nm). The scanning electron microscopy also confirms the porosity in the sample, useful in sensing applications. The FT-IR analysis confirms the presence of physical interaction between SnO2 and Al2O3 due to the slight shifting and broadening of characteristic bands. The UV-Vis analysis confirms the semiconducting nature because of direct transition of electrons into the 0.5SnO2–0.5Al2O3 nanocomposites.

Grain growth and sintering in Bi–(Pb)—Sr—Ca—Cu—O superconductors made by sol-gel

1994 ◽  
Vol 9 (2) ◽  
pp. 286-291 ◽  
Author(s):  
Kunsong Ma ◽  
Alain C. Pierre
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Citric Acid ◽  
Grain Growth ◽  
Sol Gel ◽  
Gel Processing ◽  
Scanning Electron

Bi—(Pb)—Sr—Ca—Cu—O superconductors were synthesized by sol-gel processing from nitrates by complexation with citric acid. Their grain growth and sintering above 800 °C were studied by Scanning Electron Microscopy (SEM) and Brunauer, Emmett, Teller (BET) porosimetry. The sintering was limited by anisotropic grain growth, and microcracks in 2212 phase grains were created due to the formation of 2223 phase.

Preparation of Borosilicate Xerogel and Research on its Mineralization

2012 ◽  
Vol 476-478 ◽  
pp. 2059-2062
Author(s):  
Chen Wang ◽  
Ya Dong Li ◽  
Gu Qiao Ding
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Ph Value ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compositional Changes ◽  
Scanning Electron

Tributyl borate was first adopted for the introduction of boron in the preparation of bioactive borosilicate xerogel by sol-gel method. The xerogel reacted continuously in 0.25M K2HPO4 solution with a starting pH value of 7.0 at 37 °C for 1day. The structural, morphologies and compositional changes resulting from the conversion were characterized using X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. The results indicated that speed of formation of HA was cut way back on the time with the addition of boron and the induction period for the HA nucleation on the surface of the borosilicate xerogel was short than 1 days. The conversion mechanism of the borosilicate xerogels to hydroxyapaptite was also discussed.

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