| Super hydrophilic surface has high surface energy and strong self-cleaning function,It has a wide application prospect in the fields of architecture and medicine.However,the transparent super hydrophilic film does not affect the ornamental and has enough hydrophilic anti-fog function,It can bring more convenience to people's life and more widely be used.such as Car windshield,Building glass,bathroom mirror,etc.At present,the methods of preparing superhydrophilic surface mainly include sol-gel method,gas phase method,electrochemical method,etc.These methods are difficult to be popularized in practical production because of complicated technology and large investment in equipment.Uv curing is a new method to prepare super hydrophilic surface in recent years,The advantages of uv curing is high efficiency,energy saving and curing at room temperature.But,there are few studies on the preparation of hydrophilic films by uv curing,In this paper,the super hydrophilic surface is prepared by uv curing coating with acrylic acid and methacrylic acid as the principal part.And the effects of different material composition,content and curing time on the hydrophilic performance are also discussed.However,most of the hydrophilic coatings have poor surface properties and wear resistance.Therefore,in this paper,nano-micro thermal imprinting technology is used to change the substrate morphology and support the microstructure to improve the wear resistance of superhydrophilic film surface.In order to prepare the abrasion resistant super hydrophilic surface,and finally meet the requirements of transparency,the paper mainly does the following work:By means of hot stamping,polycarbonate(PC)as the substrate and SiO2 microspheres are combined with different mesh screen as microstructures to form a super hydrophilic surface on the surface of PC films during the hot stamping process.The contact angle of material surface can reach 0° under the impression of 100 mesh screen with super hydrophilic effect.SiO2 microspheres are closely distributed on the material surface and have good hydrophilic and wear resistance.But it has low light transmittance,high haze and poor transparency.In order to improve the transparency of the hydrophilic film,the formulation of the uv-curable coating is further discussed,and the hydrophilic coating is prepared on the surface of PC film by uv-curable method.Select appropriate coating formula:Acrylic acid,methacrylic acid and ester monomers are used as the main functional monomers and the coating is uniformly mixed in different proportions and cured directly under ultraviolet irradiation.Under the final proportion,the contact angle from 82° to 4.08°,the polymer films with super hydrophilic properties are successfully prepared.The light transmittance of the prepared hydrophilic film is 92%,which is basically the same as PC of 92.2%.And the hardness is stable around 3H.The resistance to friction can last 50-70 laps under the friction of the friction wheel,and still maintain good hydrophilicity.By micro-nano embossing,Microlens,V groove and hemispherical microstructure are used as supporting structure to modify the substrate surface.After modification of base material contact Angle changed from 82° to 92°,The average degree of haze is 5.6%,After curing by super hydrophilic coating,the haze back to 0.43%,the transparent is same as PC and hydrophilic can still can reach 4.68°.The friction resistance can be maintained for 90 laps under 30KPa pressure friction without completely losing its hydrophilicity. |
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