Cerous Ions Promote Surface Modification Of Fluoropolymers By UV-Irradiation

Fluoroplastics are the most inert and hydropobic polymers, these properties have limited their application in many fields. In order to improve their performance, it is necessary to increase the surface polarity by surface modification. Their wettability and biocompatibility can be modified by the incorporation of polar functionality. Poly(acrylic acid), Poly(Hydroxyethyl methacrylate), Poly(glycidyl-methacrylate), Poly(N, N'—Methylene bisacrylamide), Poly(N-Isopropyl acrylamide) and Poly(ethylene glycol) methyl ether methacrylate can be grafted to several fluoropolymers by UV irradiation under the catalysis of Ce(III) in the acid medium.Modification effect has been contrasted when UV-irradiation and acrylic acid modification, cerous ions and ceric ions also have important effect on the modification of FEP film. Experiments have indicated that Ce3+/H+ system can promote the initiation of UV light to FEP film.X-ray photoelectron spectroscopy (XPS) characterization demonstrated that PAA had been introduced to the surface of the FEP film, the contact angle(CA) of water had been improved to decrease from 118.0°to 45.0°. The influence factors, such as the concentration of cerous ions and AA, reaction temperature and the intensity of the UV light on the grafting yield(GY%) and CA were discussed. Mouse immunoglobulin G(IgG) adsorption experiments demonstrated that the protein content of the modified film surface were less than the original FEP film. Specific pattern had been achieved by the use of a photo mask. Atomic force microscope analysis indicate that the surface roughness Ra of the FEP-g-PAA had decreased from 42.73nm to 13.51nm。Many other polymers can also be introduced to the surface of many other fluoroplastics, making their hydrophility improved.