In this research work silica coating was produced on nickel substrates by a sol-gel process. In order to increase the rate of hydrolysis and to reduce the rate of polymerization several acid catalysts including nitric...In this research work silica coating was produced on nickel substrates by a sol-gel process. In order to increase the rate of hydrolysis and to reduce the rate of polymerization several acid catalysts including nitric acid-hydrochloric acid, acetic acid, hydrochloric acid and nitric acid were add to silica sol. Conversely, in order to control the rate of hydrolysis and to increase the rate of polymerization, basic catalyst of ammonia and ammonia hydroxyl were introduced in to the solution. Nickel specimens of known surface roughness were chemically cleaned and prepared by dipping in the sols. In order to produce a suitable silica coating the drying and firing cycles were optimized on these substrates. The structure and uniformity of the coatings produced were examined by scanning electron microscopy. Coatings composition was determined using glow discharge optical spectroscopy and EDAX microanalysis. Experimental result showed that hydrochloric acid, acetic acid, ammonia and acetic acid - ammonia are suitable catalytic agents for silica coating formation on nickel type substrate.展开更多
A new silica antireflective coating with improved hydrophobicity and optical stability in a vacuum is obtained by a two-step route. Firstly, silica sols are prepared with a sol-gel process, in which tetraethyl orthosi...A new silica antireflective coating with improved hydrophobicity and optical stability in a vacuum is obtained by a two-step route. Firstly, silica sols are prepared with a sol-gel process, in which tetraethyl orthosilicate is utilized as a precursor. And by introduction of fluorine containing glycol into the sols, the porosity of silica particles and surface polarity of the coatings are decreased. Afterward, coatings are constructed with low surface roughness by modification of PMBA-PMMA. The coatings retain transmission of up to 99.6%, and laser damage threshold of about 50 J/cm^2 at a wavelenth of 532 nm （1-on-1. 10 ns）展开更多
Aerogels are predominantly mesoporous,extremely lightweight,low density(∼0.003 g/cm 3)and thermally insulat-ing materials.Over the years,aerogels have gained increasing attention due to their extraordinary properties...Aerogels are predominantly mesoporous,extremely lightweight,low density(∼0.003 g/cm 3)and thermally insulat-ing materials.Over the years,aerogels have gained increasing attention due to their extraordinary properties(light,heat,sound,electricity and force)and application potentials in varieties of fields.Several studies have been carried out regarding aerogel preparation and its applications in coatings on different substrates.In this review,an overview of aerogels preparation and their application progress in coatings of most common substrates is presented.Attention is paid to aerogel coatings of textiles,leather,and substrates other than leather and textiles for special functionali-ties that could address the application progress in coatings.This review will help to inspire scientists and engineers towards novel aerogel materials and technologies to boost the industrial fabrication of flexible advanced materials.展开更多
基金supported by electroceramics research center in Malek Ashtar university of Technology(Shahin-Shahr)and Isfahan university of Technology
文摘In this research work silica coating was produced on nickel substrates by a sol-gel process. In order to increase the rate of hydrolysis and to reduce the rate of polymerization several acid catalysts including nitric acid-hydrochloric acid, acetic acid, hydrochloric acid and nitric acid were add to silica sol. Conversely, in order to control the rate of hydrolysis and to increase the rate of polymerization, basic catalyst of ammonia and ammonia hydroxyl were introduced in to the solution. Nickel specimens of known surface roughness were chemically cleaned and prepared by dipping in the sols. In order to produce a suitable silica coating the drying and firing cycles were optimized on these substrates. The structure and uniformity of the coatings produced were examined by scanning electron microscopy. Coatings composition was determined using glow discharge optical spectroscopy and EDAX microanalysis. Experimental result showed that hydrochloric acid, acetic acid, ammonia and acetic acid - ammonia are suitable catalytic agents for silica coating formation on nickel type substrate.
基金supported by the National Major Project of Science and Technology under Grant No.2013ZX04006011-101
文摘A new silica antireflective coating with improved hydrophobicity and optical stability in a vacuum is obtained by a two-step route. Firstly, silica sols are prepared with a sol-gel process, in which tetraethyl orthosilicate is utilized as a precursor. And by introduction of fluorine containing glycol into the sols, the porosity of silica particles and surface polarity of the coatings are decreased. Afterward, coatings are constructed with low surface roughness by modification of PMBA-PMMA. The coatings retain transmission of up to 99.6%, and laser damage threshold of about 50 J/cm^2 at a wavelenth of 532 nm （1-on-1. 10 ns）
基金This work was financially supported by the National Foreign Experts Program-Foreign Youth Talent Program(QN20200173001)the National Key R&D Pro-gram(2020YFE0203800)the Research and development project of China Leather and Footwear Research Institute Co.Ltd.(2021PGX02).
文摘Aerogels are predominantly mesoporous,extremely lightweight,low density(∼0.003 g/cm 3)and thermally insulat-ing materials.Over the years,aerogels have gained increasing attention due to their extraordinary properties(light,heat,sound,electricity and force)and application potentials in varieties of fields.Several studies have been carried out regarding aerogel preparation and its applications in coatings on different substrates.In this review,an overview of aerogels preparation and their application progress in coatings of most common substrates is presented.Attention is paid to aerogel coatings of textiles,leather,and substrates other than leather and textiles for special functionali-ties that could address the application progress in coatings.This review will help to inspire scientists and engineers towards novel aerogel materials and technologies to boost the industrial fabrication of flexible advanced materials.
