Study On The Preparation And Properties Of Typical Natural Mineral Anti-fog Film Materials

The problem of material surface fogging exists in various fields and has brought a great obstacle to the application scenarios of various materials.In order to solve this situation,researchers have used physical or chemical methods to process materials.Among them,the construction of hydrophilic or hydrophobic surfaces is a hot topic in today’s research.However,current materials or methods suffer from high preparation costs,complex processes,toxic materials selected and unsustainable anti-fog effects.Therefore,this paper uses natural silicate minerals,which are widely sourced,low-priced,green,safe and nontoxic,as raw materials,in order to prepare new mineral anti-fog films with significant antifog effects and stable properties.In this paper,silicate minerals were used as raw materials to prepare coating materials by purification,tabletting and roasting.The mineral types and preparation conditions of coating materials were studied.Mineral anti-fog film was prepared by vacuum evaporation coating method.The effects of coating conditions,film thickness and metal compound doping on the anti-fog performance and surface roughness of mineral anti-fog film were studied.The performance test and characterization analysis of mineral anti-fog film were carried out.The main research contents and conclusions are as follows:The optimum preparation conditions for the coating materials were studied.It was found that the best hydrophilic films were prepared when feldspar was used as the coating material and the anti-fog level could reach the first level when the mineral purity reached 95%.The optimum conditions for preparing coating materials were as follows:the amount of deionized water was 5 wt%,the tabletting time was 10 min,the calcination temperature was 500℃,and the calcination time was 2 h.There are adsorbed water,interlayer water and bound water in the coating material,and the structure of the mineral is Si-O-Si and Si-O-Al.The coating material gradually removes the water as the temperature increasing.The coating material was prepared into a mineral anti-fog film by vacuum evaporation method.When the substrate temperature was 60℃,the film thickness was 100 nm,and the metal compound addition was 1%,the prepared anti-fog film had the best anti-fog effect,which could reach the first anti-fog level.At that situation,the surface roughness of the film was the largest.When the film thickness gradually increased,the anti-fog level of the film decreased and the surface roughness decreased.The maximum transmittance of the mineral anti-fog film for visible light is 92.2%,which is 4.5%higher than that of the blank substrate.Compared with the coating material,the crystallization degree of the film becomes worse and changes to the amorphous state,which made the surface roughness become larger.But it still maintains the basic Si-O-Si and Si-O-Al structures,which made the hydrophilicity become stronger,and the anti-fog performance become better.Using the optimum conditions for coating material preparation and mineral anti-fog film preparation on spectacle lenses,the obtained spectacle samples coated with mineral anti-fog film had a lower contact angle and achieved anti-fog effect of first level and still had second level after 60 days.The sample had a transmission rate of 88%and an adhesion force of 570.379 mN to the substrate.