Preparation And Properties Of Organic-inorganic Composite Anti-fogging Coating

Fogging on the surface of transparent substrate often occurs in all areas of people's daily life.Fogging causes a series of problems because of light scattering and blurring of vision.For example,fogging of bathroom mirror and building glass will cause problems of aesthetics and convenience.Fogging on the plastic film materials of agricultural greenhouse may reduce crop yield.More seriously,fogging in medical,food,automobile and aerospace fields may cause serious health and safety problems.The preparation of anti-fogging coating is a way to change the chemical structure of substrate surface to achieve anti-fogging performance.At present,there are many methods for preparing anti-fogging coatings and materials,such as etching,plasma treatment,Lb L chemical-synthetic coating and so on.These methods can prepare surfaces with excellent anti-fogging performance.but the first three methods involve expensive instruments and complex processes,which are difficult to be industrialized on a large scale and applied to practice.Therefore,the chemical-synthetic coating method was used in this paper.The main structure of silicon oxygen silicon bond was formed by the co-hydrolysis and condensation of tetraalkoxysilane and silane coupling agent,and then hydrophilic compounds were introduced into the system to prepare an anti-fogging coating.The main contents and results of this paper were listed as follows:(1)Tetraethyl orthosilicate(TEOS),?-glycidyl ether oxypropyl trimethoxysilane(KH560),diethanolamine(DEA)were selected as the main raw materials.The diethanolamine grafted anti-fogging coatings were obtained by the process of hydrolysis,condensation,ring opening and curing reaction.The optimal reaction conditions were obtained through experiments and results,and finally the stable anti-fogging coating and uniform,continuous and transparent anti-fogging coating were obtained.The effects of KH560 / TEOS on the hydrophilicity,anti-fogging property and water resistance,solvent resistance and heat resistance of the coating were mainly studied.it was found that with the increase of KH560 / TEOS,WCA decreased from 37.17 ° to 35.20 ° and anti-fogging time increased from 20 s to 33 s,indicating that the film had good hydrophilicity and anti-fogging performance.Other tests showed that the film had good water resistance,solvent resistance,heat resistance,pencil hardness and adhesion.(2)The film with better hydrophilicity and anti-fogging property was prepared by replacing DEA with polyetheramine(PEA)(ED-600).By exploring the influence of KH560 /TEOS ratio on WCA and anti-fogging performance,it was found that with the increase of KH560 / TEOS,WCA decreased from 22.4 ° to 20.1 ° and water droplets had obvious spreading trend in 15 s,WCA decreased to 8.58 ° and anti-fogging time increased from 120 s to 138 s,indicating that the film had better hydophilicity and anti-fogging performance than DEA system.At the same time,the film retained other excellent properties.