Research On The Preparation And Durability Of Superhydrophilic Anti-fog Coating

Transparent glass is widely used,but in actual use,due to changes in temperature caused by environmental changes,water vapor in the air is likely to condense into water droplets on the surface of the substrate,resulting in mist,a sharp drop in its transparency and visibility.Therefore,how to perform anti-fog treatment on transparent glass has gradually attracted the attention of researchers and the industry.Among them,the superhydrophilic surface coating technology that can actively prevent fog has unique advantages such as ease of construction,continuous protection,and economy of operation and maintenance costs,and is the most promising anti-fog technology.However,the current superhydrophilic anti-fog coating exphit low hardness,not resistant to wear,short service life and easily polluted.The development of long-lasting,durable and anti-pollution,anti-fog coatings has become an important research direction in this field.Therefore,this article has carried out the research on the preparation technology of the superhydrophilic anti-fog coating on the glass surface and its durability and self-cleaning characteristics.The inorganic superhydrophilic anti-fog coating is prepared by blending SiO₂ nano sol and anionic surfactant C14-16 sodium alkenyl sulfonate,and the inorganic superhydrophilic anti-fogging coating is prepared by dipping and pulling method.The experiment found that when SiO₂ nano sol with a particle size of less than 10nm is added at 4wt%,the coating has the densest and uniform microstructure and the best mechanical wear resistance.The coating exphit the most dense,uniform microstructure and the best mechanical wear resistance.Maintain good anti-fog performance.In addition,after adding 3.0wt‰of inorganic hard filler Ti O₂ sol and Al₂O₃ sol to enhance the mechanical properties of the coating,the hardness of the coating reached 3H.Inorganic superhydrophilic anti-fog coating uses small particle size inorganic nanoparticles to accumulate to form a hard microstructure,which has a certain degree of wear resistance,but the lack of cross-linking between SiO₂ nanoparticles makes the coating still porous,which makes it difficult to resist the abrasion tester.The hard wear.In order to improve the wear resistance,the cross-linking agent TEOS is introduced into the coating and its incomplete hydrolysis under acidic conditions is used to strengthen the cross-linking between SiO₂ nanoparticles.The paint is adjusted to acidity with acetic acid and 1.0wt%TEOS is added to obtain an acid cross-linked superhydrophilic anti-fog coating,which is sprayed to prepare an acid cross-linked superhydrophilic anti-fog coating.The microscopic morphology of the coating is dense and uniform,and the SiO₂ nanoparticles are tightly cross-linked,and a single spherical nanoparticle is almost invisible.The coating remains anti-fogging after the CS-10F wheel rubs for 150r.Acetic acid-catalyzed TEOS hydrolysis enhances the cross-linking between SiO₂ nanoparticles,and obtains a dense acid cross-linked superhydrophilic anti-fog coating on the surface,which further improves the abrasion resistance of the coating,but the coating has poor blistering resistance.The anti-fogging property will be lost after 96h in water.In the process of soaking in water,water will destroy the bond between SiO₂ nanoparticles,causing the coating to become loose and porous and the adhesion to the substrate deteriorates.After 96 hours of soaking in water,the adhesion of the coating drops to level 4.For this reason,a water-based transparent resin is used to wrap the SiO₂nanoparticles,and the adhesion between the resin and the substrate is used to improve the stability of the coating after long-term soaking in water.Preferably,the water-based transparent polyacrylic resin is mixed into the coating at 1.0 wt%,and the coating still has 0-level adhesion after being immersed in deionized water for 96 hours.After selecting the formulation of the organic-inorganic composite superhydrophilic anti-fog coating with the best comprehensive durability,the preparation process was optimized.Oxygen plasma activation of the surface can improve the initial wettability of the substrate,and obtain a substrate surface with an initial contact angle of less than 15°.Combined with the alternate dry and wet-spray process,the roughness of the dry-spray coating can be reduced and the light transmittance of the preparation is above 90%.