Micro to mesoporous SiO2xerogels: the effect of acid catalyst type in sol–gel process

2021 ◽  
Author(s):  
Cristián Huck-Iriart ◽  
Noé J. Morales ◽  
María Lidia Herrera ◽  
Roberto J. Candal
Keyword(s):  
Sol Gel ◽  
Acid Catalyst ◽  
Sol Gel Process ◽  
Catalyst Type

Designing hierarchical porosity in tin oxide monoliths and their application as solid acid catalyst

2021 ◽  
Author(s):  
Yoshinao Suzuki ◽  
George Hasegawa ◽  
Kazuyoshi Kanamori ◽  
Kazuki Nakanishi
Keyword(s):  
Phase Separation ◽  
Tin Oxide ◽  
Solid Acid ◽  
Aprotic Solvent ◽  
Low Cost ◽  
Solid Acid Catalyst ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Hierarchical Porosity ◽  
Sol Gel Process

Hierarchically porous tin oxide monoliths have been prepared from a low-cost tin(IV) chloride precursor through an epoxide-mediated sol-gel process in an aprotic solvent N,N-dimethylformamide. Phase separation is induced in the...

scholarly journals The Effect of Catalyst in the Process of Nano-Silica Particle Formation as a Hydrophobic Material

2018 ◽  
Vol 2 (3) ◽  
pp. 152
Author(s):  
Ikhwanul Muslim ◽  
Wulan Safrihatini ◽  
Witri Aini
Keyword(s):  
Tensile Strength ◽  
Colloidal Suspension ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Phase Changes ◽  
Nano Silica ◽  
Base Catalysts ◽  
Sol Gel Process ◽  
Silk Fabrics ◽  
Hydrophobic Material

<p>Nano Silica is known as a hydrophobic material used to coat the material that further modifies the surface properties of the material. In this study the process of making nano silica material is using sol-gel method. The sol gel process is defined as the process of forming an inorganic compound through chemical reaction in solution at a low temperature wherein the process a phase changes from the colloidal suspension (sol) to a continuous liquid phase (gel). The types of catalyst were studied. The result was then applied to cotton, polyamide and silk fabrics. Acid catalyst showed the greatest moisture reduction based on Moisture Content and Moisture Regain evaluation in cotton and polyamide fabrics, whereas base catalysts showed a significantly less moisture reduction on the three fabrics. The use of these types of catalyst will also affect the value of the tensile strength of each fiber. Tensile test results showed that the use of acid catalysts decreased the maximum tensile strength in cotton fabrics by 88.57%, compared to polyamide and silk fabrics and the use of base catalyst showed less significant decreased on tensile strength for all fabrics.</p>

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.

Structure-Related Mechanical Properties of Ormosils by SOL-GEL Process

1992 ◽  
Vol 271 ◽  
Author(s):  
Yi Hu ◽  
John D. Mackenzie
Keyword(s):  
Mechanical Properties ◽  
Reaction Temperature ◽  
Fracture Strength ◽  
Modulus Of Elasticity ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Polydimethyl Siloxane ◽  
Organically Modified Silicates ◽  
Sol Gel Process ◽  
Organically Modified

ABSTRACTThe mechanical properties corresponding to the different structures of organically modified silicates (Ormosils) prepared by the sol-gel process were studied. Tetraethoxysilane (TEOS) and polydimethyl siloxane (PDMS) were used as the inorganic and polymeric components, respectively. Large variations in the microstructure of the Ormosils were found by changing the reaction temperature, and the content of PDMS, acid catalyst (HCI),and water. The structure of the Ormosils and the mechanical properties were correlated by the edge connectivity. Modulus of elasticity and fracture strength were used to study their relations Ormosils structures.

scholarly journals Organo-Silica Membrane Prepared from TEOS-TEVS Modified with Organic-Acid Catalyst for Brackish Water Desalination

2021 ◽  
Vol 16 (1) ◽  
pp. 11-18
Author(s):  
Muthia Elma ◽  
Aptar Eka Lestari ◽  
Anna Sumardi ◽  
Zaini Lambri Assyaifi ◽  
Adi Darmawan ◽  
...  
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Silica Matrix ◽  
Water Desalination ◽  
Feed Water ◽  
Silica Membrane ◽  
Vinyl Silane ◽  
Sol Gel Process ◽  
Feed Water Temperature

The sol gel process is one of the processes used in the manufacture of thin films on membranes because it can control the pore size in the resulting silica matrix. In addition, another way to build membrane size can be done by adding catalysts and precursors to be used. In this study, using a combination of tetraethyl ortho silicate (TEOS) and triethoxy vinyl silane (TEVS) precursors and citric acid as a catalyst to produce a silica matrix with mesoporous size so that it is suitable for application in the desalination process. The organo silica membrane was calcined at 350 ° C for 1 hour using the RTP calcination technique under vacuum, thus preventing the decomposition of carbon in the silica matrix. The membrane was dipcoated 4 times to obtain 4 layers. The FTIR (Fourier-transform Infrared Spectroscopy) test was carried out to see the functional groups on xerogel, namely silanol, siloxane and carbon. In addition, the performance of this membrane is carried out by desalination through pervaporation using 0.3% NaCl feed water with variations in feed air temperature, namely 25 ℃, 40 ℃ and 60 ℃. The resulting flux of air value increased with increasing feed water temperature, namely 6.1; 11.2; and 12.1 kg.m-2h-1 while the resulting salt rejection was 99.72; 99.64 and 99.23%. So that the organo silica membrane is suitable when applied to the desalination process through pervaporation.  

Influence of Catalyst in Synthesizing Brookite Thin Film Coating

2017 ◽  
Vol 264 ◽  
pp. 5-8
Author(s):  
Nur Dalilah Johari ◽  
Zulkifli Mohd Rosli ◽  
Jariah Mohamad Juoi ◽  
Muharniza Azinita Musa
Keyword(s):  
Thin Film ◽  
Grain Size ◽  
Surface Morphology ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Film Coating ◽  
Base Catalyst ◽  
Thin Film Coating ◽  
Catalyst Type ◽  
Different Temperatures

Brookite is the least known titanium dioxide (TiO2) crystallographic phases compare to anatase and rutile. In a sol-gel process, very few works are devoted on synthesizing pure brookite as a thin film coating and usually brookite co-exist with anatase and rutile as a byproduct. This study is performed as an attempt to produce brookite thin film coating via sol-gel dipping method. In this study, the influence of catalyst type on TiO2 phases, morphology and grain size were investigated. Hydrochloric acid (HCl) is used for an acid catalyst and sodium hydroxide (NaOH) is used as base catalyst. All of the TiO2 films were deposited on a glass substrate and heated at four different temperatures of 400°C, 450°C, 500°C and 550°C for 3 hours. X-ray diffraction (XRD) is employed to analyze the phases and the grain size acquired. Images on the surface morphology are obtained with Scanning Electron Microscope (SEM). Results showed that brookite phase exist only for base catalyst with a grain size of 27.40 nm for all of the selected temperatures except at 550°C. SEM results revealed that the surface morphology of the deposited TiO2 film with base catalyst comprised of agglomerated particle networks. In contrast, the surface morphology of the deposited TiO2 film with acid catalyst seems more compact and uniform with an XRD pattern of amorphous-like characteristic having grain size of less than 3 nm.

Effects of sol–gel process parameters on the anticorrosive performance of phosphosilicate hybrid coatings for carbon steel: structural and electrochemical studies

2018 ◽  
Vol 42 (16) ◽  
pp. 13442-13452 ◽  
Author(s):  
Thi Trang Phan ◽  
Fouad Bentiss ◽  
Charafeddine Jama
Keyword(s):  
Heat Treatment ◽  
Process Parameters ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Hybrid Coatings ◽  
Electrochemical Studies ◽  
Treatment Procedure ◽  
Sol Gel Process ◽  
Ethyl Phosphate ◽  
Heat Treatment Procedure

The effects of several sol–gel process parameters such as acid catalyst addition and the heat treatment procedure on porosity and anticorrosive properties were investigated for phosphosilicate sol–gel hybrid coatings prepared from 3-[(methacryloyloxy)propyl] trimethoxysilane (MEMO) and bis-[2-(methacryloyloxy)ethyl] phosphate (BMEP).

The crystallization of thin-film ceramics

1992 ◽  
Vol 50 (1) ◽  
pp. 338-339
Author(s):  
J.M. Schwartz ◽  
L.F. Francis ◽  
L.D. Schmidt ◽  
P.S. Schabes-Retchkiman
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Sol Gel ◽  
Processing Route ◽  
Small Areas ◽  
Ceramic Thin Films ◽  
Complex Shapes ◽  
Sol Gel Process ◽  
Ceramic Precursors ◽  
Crystalline Ceramic

Ceramic thin films and coatings are of interest for electrical, optical, magnetic and thermal barrier applications. Critical for improved properties in thin films is the development of specific microstructures during processing. To this end, the sol-gel method is advantageous as a versatile processing route. The sol-gel process involves depositing a solution containing metalorganic or colloidal ceramic precursors onto a substrate and heating the deposited layer to form a crystalline or non-crystalline ceramic coating. This route has several advantages, including the ability to create tailored microstructures and properties, to coat large or small areas, simple or complex shapes, and to more easily prepare multicomponent ceramics. Sol-gel derived coatings are amorphous in the as-deposited state and develop their crystalline structure and microstructure during heat-treatment. We are particularly interested in studying the amorphous to crystalline transformation, because many key features of the microstructure such as grain size and grain size distribution may be linked to this transformation.

Epitaxial Growth of Sr0.3Ba0.7Nb2O6 Thin Films Prepared by Sol-Gel Process

1999 ◽  
Vol 606 ◽  
Author(s):  
Keishi Nishio ◽  
Jirawat Thongrueng ◽  
Yuichi Watanabe ◽  
Toshio Tsuchiya
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Epitaxial Growth ◽  
Raw Materials ◽  
Substrate Surface ◽  
Sol Gel ◽  
Tungsten Bronze ◽  
Monomethyl Ether ◽  
Tetragonal Tungsten Bronze ◽  
Sol Gel Process

AbstructWe succeeded in the preparation of strontium-barium niobate (Sr0.3Ba0.7Nb2O6 : SBN30)that have a tetragonal tungsten bronze type structure thin films on SrTiO3 (100), STO, or La doped SrTiO3 (100), LSTO, single crystal substrates by a spin coating process. LSTO substrate can be used for electrode. A homogeneous coating solution was prepared with Sr and Ba acetates and Nb(OEt)5 as raw materials, and acetic acid and diethylene glycol monomethyl ether as solvents. The coating thin films were sintered at temperature from 700 to 1000°C for 10 min in air. It was confirmed that the thin films on STO substrate sintered above 700°C were in the epitaxial growth because the 16 diffraction spots were observed on the pole figure using (121) reflection. The <130> and <310> direction of the thin film on STO were oriented with the c-axis in parallel to the substrate surface. However, the diffraction spots of thin film on LSTO substrate sintered at 700°C were corresponds to the expected pattern for (110).

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