scholarly journals Functionalization of Si-C Using TEOS (Tetra Ethyl Ortho Silica) as Precursor and Organic Catalyst

2020 ◽  
Vol 148 ◽  
pp. 07008 ◽  
Author(s):  
Riani Ayu Lestari ◽  
Muthia Elma ◽  
Erdina Lulu Atika Rampun ◽  
Anna Sumardi ◽  
Adhe Paramitha ◽  
...  
Keyword(s):  
Citric Acid ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Silica Xerogel ◽  
Silica Network ◽  
Infrared Band ◽  
Oh Groups ◽  
Structured Materials ◽  
Sol Gel Process ◽  
Organic Catalyst

Silica network was tailored configuring siloxane (Si-O-Si) and silanol (Si-OH) groups which are essential to produce porous-structured materials. As silanols are hydrophilic, react with water to form fouling. This research address to actualize strategy for synthesizing highly functionalized silica carbon (Si-C) using hybrid organic-inorganic structures as the primary method for improving hydro-stability by employing precursor TEOS and organic catalyst through a sol-gel process. Catalysis employs citric acid or citric acid-ammonia whereas carbon templated into silica network. The synthesis scheme involves: a) sol-gel process at 0°C and b) calcination. Silica sol dried into xerogels were prepared and calcined at 200°C and 250°C. Characterization of xerogels showed the infrared band areas of the organic groups to evaluate the thermal stability. For xerogel employed single (pH 5.5) and dual (pH 7.65) catalyst, infrared spectra showed mostly look similar Si-C area at similar wavelength. Silica xerogel is more effectively prepared from TEOS with one-step single acid catalyst including calcination.

Effect of annealing on fluorescence of Ce3+-doped silica prepared by sol-gel process

2000 ◽  
Vol 15 (11) ◽  
pp. 2364-2367 ◽  
Author(s):  
H. J. Bi ◽  
W. P. Cai ◽  
H. Z. Shi ◽  
L. D. Zhang ◽  
B. D. Yao
Keyword(s):  
Vapor Deposition ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Structural Evolution ◽  
Chemical Vapor ◽  
Emission Peak ◽  
Silica Network ◽  
Oh Groups ◽  
Sol Gel Process ◽  
Different Temperatures

We prepared Ce3+-doped silica by the sol-gel method and studied the effect of annealing on fluorescence of these samples. Different fluorescence was observed for samples annealed at different temperatures, changing gradually from solution like fluorescence to fluorescence similar to that observed in the Ce3+-doped silica prepared by chemical vapor deposition. It was found that the emission intensity first decreased with increasing annealing temperature until 500 °C, and then increased with the temperature ranging from 500 to 950 °C. Meanwhile, the emission peak showed a large red shift and an obvious broadening. These changes were attributed to the annealing-induced structural evolution in silica: Ce3+ ions changed from coordinating with water and terminal OH-groups to embedding in silica network.

Development of temporal spectroscopic properties for Xerogel matrices doped with Rhodamine 6G dye

Open Physics ◽  
2006 ◽  
Vol 4 (3) ◽  
Author(s):  
Abbas Al-Wattar ◽  
Baha Chiad ◽  
Wesam Twej ◽  
Sarmed Al-Awadi
Keyword(s):  
Fluorescence Spectra ◽  
Rhodamine 6G ◽  
Sol Gel ◽  
Blue Shift ◽  
Spectroscopic Properties ◽  
Dye Molecules ◽  
Absorption And Fluorescence Spectra ◽  
Silica Network ◽  
Sol Gel Process ◽  
Two Parameters

AbstractThe solid host of a laser dye modifies its spectroscopic properties with respect to its liquid host. During the Sol-Gel process the dye molecules suffer from changing their environment. Two parameters affect this matter, the change in the concentration due to the evaporation of the solvent (drying) and the caging of dye molecules inside the pores or attachment to the silica network. Rhodamine 6G absorption and fluorescence spectra with different concentrations, during Sol-Gel time processing, have been studied. Both, absorption and fluorescence spectra of the dye in the solid host, for different concentrations, show a blue-shift relative to its liquid phase.

Deconvolution of TEOS/TEVS Xerogel by Single or Dual Organic Catalyst Addition

2021 ◽  
Vol 6 (2) ◽  
pp. 208-214
Author(s):  
Anna Sumardi ◽  
Muthia Elma ◽  
Aptar Eka Lestari ◽  
Zaini Lambri Assyaifi ◽  
Adi Darmawan ◽  
...  
Keyword(s):  
Citric Acid ◽  
Unit Area ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Area Ratio ◽  
Silica Sol ◽  
Suitable Material ◽  
Vinyl Silane ◽  
Filtration Material ◽  
Silica Precursor

Currently, xerogel has been applied as a filtration material, especially in membrane desalination. However, the xerogel matrix structure for desalination have to be designed properly in order to allow rejection of salt and obtain good hydro-stability, thus, silica precursor in the form of TEOS (tetraethyl orthosilicate)/TEVS (triethoxy vinyl silane) and organic acid catalyst are suitable material for fabrication. The aim of this study is therefore to fabricate and perform deconvolution of TEOS/TEVS xerogel by adding single or dual catalyst, using FTIR (Fourier-transform Infrared Spectroscopy) and Fityk software. The xerogel was fabricated by dried silica sol and calcined using RTP technique (rapid thermal processing) at 450 °C.  Prior to this fabrication, the silica sol was synthesized by sol gel method, using a mixture of silica precursor TEOS/TEVS, ethanol solvent, and varied addition of single catalyst (citric acid) as well as dual catalyst (citric acid + ammonia) for 2 hours, at 50 °C. Subsequently, the xerogel was characterized by FTIR and the deconvolution was obtained through Gaussian approach, with Fityk software. All TEOS/TEVS xerogel samples indicated existence of silanol (Si-OH), siloxane (Si-O-Si) and silica-carbon (Si-C) functional groups. The xerogel deconvolution of TEOS/TEVS using single catalyst exhibit a peak area ratio of Si-OH/Si-O-Si, and this is similar to the dual catalyst counterpart of 0.24 (unit area) and 1.86 (unit area), for Si-C area ratio. This shows the addition of single catalyst was enough to produce deconvolution in TEOS/TEVS xerogel, dominated by siloxane functional group and carbon bonds with the ability to enhance membrane material hydro-stability’s fabrication.

Synthesis of BaMoO4 Nanocrystallites Using Sol-Gel Process

2012 ◽  
Vol 535-537 ◽  
pp. 469-472
Author(s):  
Quan Zheng Zhang
Keyword(s):  
Citric Acid ◽  
Optical Property ◽  
Sol Gel ◽  
Sol Gel Process

BaMoO4nanocrystallites were synthesized successfully using Sol-gel process with (NH4)6Mo7O24•4H2O, BaCl2•2H2O, citric acid and PEG400 as original materials. The result shows that well-crystallized BaMoO4nanoparticles were formed at 600°C with size of ca.50nm. The synthesized BaMoO4nanocrystallites were characterized by XRD and IR, and the optical property was studied as well.

Preparation and Properties of PVC-Silica Composites using Different Catalysts Via Sol-Gel Process

1999 ◽  
Vol 576 ◽  
Author(s):  
Khan M. Asif ◽  
M.I. Sarwar ◽  
Z. Ahmad
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Sol Gel ◽  
Silica Network ◽  
Transparent Films ◽  
Sol Gel Process ◽  
Gel Technique ◽  
In Situ Generation ◽  
Scanning Electron

Novel micro-composites from Polyvinyl chloride (PVC) and silica were prepared using sol-gel technique. Different catalysts were used for the in-situ generation of silica network from tetraethylorthosilicate (TEOS) in the PVC matrix. Thin transparent films containing various proportions of silica in PVC were cast by the solvent elution technique. Mechanical properties of these films were studied. The results showed an increase in the value of Young's modulus and strain at rupture by the addition of small amount of silica in PVC. However, the stress at yields point and stress at rupture decreased with the addition of silica contents. Scanning electron microscopy (SEM-EDAX) studies were also performed on these samples.

Development of Nanomaterials from Natural Resources for Various Industrial Applications

2009 ◽  
Vol 67 ◽  
pp. 71-76 ◽  
Author(s):  
V. Rajendran
Keyword(s):  
Natural Resources ◽  
Sol Gel ◽  
Industrial Applications ◽  
Nano Particles ◽  
Nano Materials ◽  
Chemical Methods ◽  
Structured Materials ◽  
Nano Alumina ◽  
Sol Gel Process ◽  
Antibacterial Textile

In the present study, the synthesis of nano structured materials such as nano alumina (Al2O3), nano silica (SiO2), and nano hydroxyapatite (HAp) have been discussed for industrial applications. The oxide nano materials are prepared employing chemical methods from natural resources. The HAp is prepared employing sol-gel process using chemical precursors. The synthesised nano alumina (Al2O3) powder has been used to improve the physicochemical properties of refractories. The prepared nano particles employing different process techniques have been characterized using XRD, FTIR, EDAX and SEM studies. The silica nano particles have been coated on textiles to get the wrinkle free/antibacterial textile cloths/products. The synthesized nanoparticles from natural resources have been used in various industrial applications such as refractories, textiles and biomedical field.

scholarly journals Synthesis and Characterization of Trimethylchlorosilane-Modified Silica Xerogel

2020 ◽  
Vol 23 (7) ◽  
pp. 249-254
Author(s):  
Sellen Tanheitafino ◽  
Anis Shofiyani ◽  
Risya Sasri ◽  
Rudiyansyah Rudiyansyah
Keyword(s):  
Contact Angle ◽  
Citric Acid ◽  
Sodium Silicate ◽  
Sol Gel ◽  
Volume Ratio ◽  
Silica Xerogel ◽  
Silica Xerogels ◽  
Modified Silica ◽  
Average Pore ◽  
Pore Size Distributions

Modification of silica xerogel with TMCS (trimethylchlorosilane) reagent has been carried out to improve the hydrophobicity of silica xerogel. Silica xerogel was synthesized based on the sol-gel method using sodium silicate as a precursor, and citric acid as a catalyst, with a mole ratio of sodium silicate and citric acid, was 0.172: 0.004. The sol-gel process was carried out through several stages, i.e., hydrolysis and condensation of sodium silicate to form sol, gelation (sol transition to gel), aging, and drying. Surface modification was performed by studying the effect of TMCS: methanol: petroleum benzine volume ratio of 0.5:1:1, 1:1:1, 1.5:1:1, 2:1:1, and 2.5:1:1 on the characteristics of silica xerogel synthesized. FTIR, SEM, and GSA characterized the synthesized results. The results of FTIR characterization on silica xerogel with volume ratios of 2:1:1 and 2.5:1:1 indicate the presence of the Si‑C group absorption at a wavenumber of 848.68 cm-1 which shows that the formation of silyl groups on the modified silica xerogel surfaces occurs at a TMCS: methanol: petroleum benzine ratio of 2:1:1 and 2.5:1:1. SEM results indicate that the silica xerogels produced are porous. Meanwhile, the GSA analysis results show that the pore size distributions are in the mesoporous region with an average pore radius of 8-13 nm. The greater the volume of TMCS used, the higher the surface area, and the resulting xerogel’s hydrophobicity. Based on the contact angle and seeped time test, the highest hydrophobicity is produced by the material synthesized at a TMCS: methanol: PB volume ratio of 2.5:1:1 with a contact angle of 116.346°.

scholarly journals Sol-gel synthesis of α-Al2O3 with enhanced porosity via dicarboxylic acid templating

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Simon Carstens ◽  
Christian Splith ◽  
Dirk Enke
Keyword(s):  
Citric Acid ◽  
Thermal Analyses ◽  
Sol Gel ◽  
Dicarboxylic Acids ◽  
Precise Control ◽  
Sol Gel Process ◽  
Successful Establishment ◽  
The One ◽  
Α Al2o3 ◽  
Sol Gel Synthesis

AbstractOne of the major routes to synthesize macroporous α-Al2O3 is the sol-gel process in presence of templates. Templates include polymers as well as carboxylic acids, such as citric acid. By careful choice of the template, pore diameters can be adjusted between 110 nm and several µm. We report the successful establishment of plain short-chain dicarboxylic acids (DCA) as porogenes in the sol-gel synthesis of macroporous α-Al2O3. By this extension of the recently developed synthesis route, a very precise control of pore diameters is achieved, in addition to enhanced macropore volumes in α-Al2O3. The formation mechanism thereof is closely related to the one postulated for citric acid, as thermal analyses show. However, since branching in the DCA-linked alumina nuclei is not possible, close monomodal pore width distributions are attained, which are accompanied by enhanced pore volumes. This is a significant improvement in terms of controlled enhanced porosity in the synthesis of macroporous α-Al2O3.

CHARACTERIZATION ON SILICA FROM WASTE SUGARCANE BAGASSE FOR MEMBRANE FABRICATION

2016 ◽  
Vol 78 (5-4) ◽  
Author(s):  
Hamizah Mokhtar ◽  
Ramlah M. T. ◽  
Aida Isma M. I. ◽  
Nabilah Huda A. H. ◽  
Noor Sa’adah A. H. ◽  
...  
Keyword(s):  
Sugarcane Bagasse ◽  
Sol Gel ◽  
Organic Additive ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
Oh Groups ◽  
Membrane Fabrication ◽  
Sol Gel Process ◽  
Characterization Test ◽  
Silica Oxide

The used of additive enhance the surface of the membrane layer and can be choose from various material. Examples of commonly used additive in membrane are Polyethylene glycol, silica oxide, cellulose acetate and Polyvinylpyrrolidone. Silica oxide was proven have ability to minimize the fouling problem hence increase hydrophobic properties of membrane. Silica also can be extracted from rice husk ash, sugarcane bagasse, sorghum vularae seed and kenaf by precipitation method, biodigestion and sol-gel process. Silica extraction from sugarcane bagasse was chosen as the organic additive for membrane formation. In order to investigate the suitability of the material, several characterization test have been conducted. There are thermal, microscopic and spectroscopic analyses. Thermal gravimetric analysis was performed on sugarcane bagasse to determine the amount of silica that can be extracted from it. Results of TGA on sugarcane bagasse show that the peak temperature at 315.70 °C are defined as crystalline melt. After the melt transition, the baseline takings to a slightly lower position than the pre-melt baseline. The post-melt baseline changes slope as the sample begins decomposition while TGA extrapolated onset temperature of 241.56 °C as this sample decomposes. The analysis of microscopic shows that the addition of silica from sugarcane bagasse changed the surface structure of the membrane especially at top layer and sub layer. Sugarcane bagasse show bands for carboxylate (COO-) and hydroxyl (OH-) groups. The availability of negatively charged groups at the surface of sugarcane bagasse shows potential to be used as additive in membrane fabrication.

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