Study On UV Irradiation Modification Of Glass-like Carbon Films And Polyimide Films

Nowadays,as one of the important development fields in the world,surface modification technology can not only improve the surface properties of materials,but increase the lifespan and reliability of components.Also,surface modification technology can help reduce the production costs of materials and save energy,which is of great significance in promoting the development of high technology.The traditional surface modification technologies such as electroplating,thermal spraying and other technologies have become more comprehensive.And in recent years,researchers are focusing on developing emerging surface modification technologies.As a new modification method,UV irradiation can introduce or form active groups on the surface of the material,which can effectively improve the surface hydrophilicity and adhesion of the material and enhance the biological activity of the material.As a result,it is mainly applied to the modification of biomaterials and polymer materials.Based on the characteristics of ultraviolet radiation modification,we have selected biomaterial glassy carbon membranes and polymer materials polyimides for the study in this paper and studied the physical,chemical and tribological properties of the modified surface.The main findings and innovations of this article are summarized as follows:(1)This paper reveals the effect of UV irradiation modification on the surface properties of glass-like carbon films.The UV irradiation modification can improve the surface roughness,hydrophilicity,adhesion and surface energy of the glassy carbons.The above-mentioned improvement of the properties facilitates the adsorption of the glassy carbon-like cells when used as a cell culture medium.Moreover,UV irradiation modification affects the mechanical properties of glass-like carbon films,resulting in a slight decrease its hardness,while Young's modulus changed little.By studying the tribological properties before and after its modification,it is found that the friction and friction coefficient of the sample surface increases with the increase of the irradiation time,while the wear resistance of the surface has little effect on the 10 minutes before irradiation.As the time increased to 20 minutes,the wear resistance of the carbon film surface is significantly reduced.Further analysis shows that the high energy of the ultraviolet light and the strong oxidation of ozone may introduce active oxygen atoms on the surface of the glassy carbon-like film to form hydrophilic groups such as hydroxyl carboxyl groups.Likewise,the carbon film can shift to the disordered graphite phase during the modification process.(2)In addition,this paper reveals the effect of UV radiation modification on the surface properties of polyimides.UV irradiation modification can improve the surface roughness,hydrophilicity and adhesion of polyimide.The improvement of these properties is very essential when the polyimide material is used as a self-adhesive tape for a flexible plate.The results of indentation test show that with the increase of irradiation time,the mechanical properties of the polyimide material surface will be reduced,and the hardness and Young's modulus will be slightly reduced.While with the increase of irradiation time,polyimide The friction and coefficient of friction of the amine surface also increase.At the same time,the scratch test results show that under the same load,with the increase of irradiation time,the scratch depth of the sample surface gradually increases.For the sample with the same irradiation time,the depth of scratch under acidic condition,ultrapure water and atmosphere is shallow,and the wear resistance is better,while the KOH-treated sample had the deepest scratch depth at the same irradiation time,indicating that the polyimide was not resistant to alkali.Further analysis showed that the modification of the ultraviolet radiation on the polyimide surface was mainly attributed to the cleavage and cross-linking of the molecular chains.The polyimide produces radicals after UV irradiation and the free radicals and free radicals cross-linking occurs,resulting in a more stable chemical structure.Moreover,polyimide does not tolerate strong alkalis and similar modification reactions can occur under alkaline conditions,while it has good acid resistance,similar reactions do not occur under acidic conditions.(3)Futhermore,this paper demonstrates the application of UV irradiation modification.The cell culture experiment is performed on the surface of carbon film samples at different irradiation times,which has found that the bioaffinity of the surface of the sample after UV irradiation is enhanced.The adhesion and proliferation of the cells on the surface of the samples were increased for 10 minutes before irradiation,and the cells on the surface of the samples were reduced for 20 minutes.Therefore,the modification time was about 10 minutes.At the same time,we conducts scratch tests under different loads on the modified polyimide surface and processes a series of surface textures.The related experimental results provided a reference for the direct-write processing of the probe on the polyimide surface.In this paper,the effects of ultraviolet irradiation on glassy carbon-like membranes and polyimide films have been studied.The use of UV irradiation has successfully improved the biocompatibility of the glass-like carbon membrane surface and the modified polyimide surface is more suitable for direct-write processing of the probe.Related studies have important guiding significance for the application of UV irradiation modification materials.