Acid and Base Catalysts in the Hybrid Silica Sol–Gel Process

1997 ◽  
Vol 195 (2) ◽  
pp. 381-387 ◽  
Author(s):  
Cesar R. Silva ◽  
Claudio Airoldi
Keyword(s):  
Sol Gel ◽  
Silica Sol ◽  
Base Catalysts ◽  
Hybrid Silica ◽  
Sol Gel Process ◽  
Acid And Base

scholarly journals Resistance to Growth of Molds for Wood Modified with Hydrophobic Hybrid Silica Gel Containing Copper Amine Complexes

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 577
Author(s):  
Shaokun Hao ◽  
Chuanshuang Hu ◽  
Xiuyi Lin ◽  
Jin Gu ◽  
Hong Yun ◽  
...  
Keyword(s):  
Silica Gel ◽  
High Efficiency ◽  
Copper Chloride ◽  
Sol Gel ◽  
Untreated Wood ◽  
Populus Tomentosa ◽  
Amine Complexes ◽  
Hybrid Silica ◽  
Sol Gel Process ◽  
Copper Amine

Complexation copper with amine provides an effective strategy for fixation copper in wood, while hydrophobic modification improves the dimensional stability of wood. Thus, a combination of complexation and hydrophobization is expected to enhance the efficiency of copper-based biocides. In this study, hydrophobic hybrid silica gel containing copper amine complexes (MACu) was prepared through an in situ sol-gel process in wood using methyltriethoxysilane (MTES), 3-amino-propyltriethoxysilane (APTES), and copper chloride. The resistance to growth of molds for MACu modified wood (Populus tomentosa) was measured according to ASTM D3273-16. A leaching resistance test was carried out in accordance with AWPA E11-16. The results showed that only Aspergillus niger covered the surface of untreated wood blocks and no mold grew on the MACu surface even after the leaching test. MACu xerogel and MACu wood were further characterized by SEM-EDS, FTIR, and XPS. A possible schematic diagram of the reaction mechanism was proposed to explain the high-efficiency anti-mold performance of MACu wood.

The Effect of Hydrolysis Conditions on the Characteristics of PbTiO3 Gels and Thin Films

1986 ◽  
Vol 72 ◽  
Author(s):  
K. D. Budd ◽  
S. K. Dey ◽  
D. A. Payne
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Dielectric Constants ◽  
Electronic Ceramics ◽  
Base Catalysts ◽  
Acid And Base ◽  
Crystalline Films ◽  
Continuous Crack ◽  
Free Films ◽  
Hydrolysis Conditions

AbstractSol-gel processing represents a promising method of fabrication for thin films of electronic ceramics which are useful in a number of packaging and device applications. In this study, the influence of acid and base catalysts on the structure of PbTiO3 gels and films (0.1-1.0μm) was investigated, for the purpose of inducing and identifying gel structures which were the most suitable as precursors for thin dielectric layers. Continuous, crack-free films, with dielectric strengths in excess of 106 V/cm were developed. Basic solutions gelled rapidly, phase separated, and were probably more crosslinked than acidic gels. Acidic gels seemed more capable of polymeric rearrangement during drying, yielding denser amorphous structures with microcrystalline regions. High-field dielectric constants (1 MV/m ac) in the range K=30–40, and K=160–170, were determined for amorphous and crystalline films, respectively.

scholarly journals Tuning the structure and the mechanical properties of epoxy–silica sol–gel hybrid materials

RSC Advances ◽  
2016 ◽  
Vol 6 (13) ◽  
pp. 10736-10742 ◽  
Author(s):  
Berta Domènech ◽  
Ignasi Mata ◽  
Elies Molins
Keyword(s):  
Mechanical Properties ◽  
Porous Material ◽  
Hybrid Materials ◽  
Sol Gel ◽  
Silica Sol ◽  
One Pot ◽  
Sol Gel Process

A new epoxy–silica porous material prepared via one-pot sol–gel process. Mechanical properties can be continuously tuned by modifying reactant proportions.

scholarly journals Triethylphosphite as a network forming agent enhances in vitro biocompatibility and corrosion protection of hybrid organic–inorganic sol–gel coatings for Ti6Al4V alloys

2014 ◽  
Vol 2 (45) ◽  
pp. 7955-7963 ◽  
Author(s):  
A. A. El hadad ◽  
V. Barranco ◽  
A. Jiménez-Morales ◽  
G. J. Hickman ◽  
J. C. Galván ◽  
...  
Keyword(s):  
Corrosion Protection ◽  
Sol Gel ◽  
Silica Sol ◽  
In Vitro Biocompatibility ◽  
Hybrid Silica

Introduction of phosphorous into hybrid silica sol–gel coatings on Ti6Al4V gives materials demonstrating higher levels of intermolecular condensation and fibrinogen uptake as well as improved in vitro biocompatibility and corrosion protection.

Study on Preparation and Hydrophobicity of MTES Derived Silica Sol and Gel

2012 ◽  
Vol 535-537 ◽  
pp. 2563-2566 ◽  
Author(s):  
Yu Ma ◽  
Hye Ryeon Lee ◽  
Toshinori Tsuru
Keyword(s):  
Reaction Rate ◽  
Sol Gel ◽  
Phase Segregation ◽  
Silica Sol ◽  
Molar Ratio ◽  
Modified Silica ◽  
Sol Gel Process ◽  
One Step ◽  
Inorganic Precursors

The synthesis of hydrophobic sol by one-step sol-gel process ammonia catalyzed was investigated. The water molar ratio and catalyst molar ratio were discussed to prevent phase segregation during the hydrolysis and co-condensation of the organic and inorganic precursors. The reactant system with water molar ratio 70 could make the reaction rate of MTES slightly less than that of TEOS, so that the hydrolysis - condensation – gelling reaction with MTES and TEOS as co-precursors could be synchronously. With the increase of the MTES/TEOS molar ratio, the reaction rate of the silica sol preparation decreased, the hydrophobicity of the sol and gel increased as the molar ratio MTES/TEOS change from 0.5~4. But the hydrophobicity of the methyl-modified silica sol and gel prepared with pure MTES in the sol-gel process were slightly lower than that of the methyl-modified silica sol and gel prepared with MTES and TEOS as co-precursors.

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