The Study Of Ultrasound Enhanced Dopamine Coated Onto Stainless Steel Surface And The Second Modification Of Radiation Grafting HEMA

Medical stainless steel has applied in vascular stents, artificial joints, dental and other materials more and more widely. To improve the corrosion resistance of stainless steel surface, biocompatibility has become implanted stainless steel hotspot. Bionic dopamine adhesion self-polymerization and coating technology has been an effective new technology of surface modification in recent years. Our research group has found that dopamine can form a thin film in various materials under ultrasound conditions, which greatly accelerated the speed of film forming, besides, the film was more uniform and bound with the substrate also significantly enhanced.This paper studied the self-polymerization of dopamine in alkaline and oxidizing environments properties, using ultrasound to enhance dopamine-coating in the substrate surface to form a high adhesion poly-dopamine layer, and using radiation grafting method for the second modification in the stainless steel which had coated dopamine. This paper studied the physical and chemical properties, biocompatibility of stainless steel before and after modification, etc.The main work is as follows:1. Using dipping coating method and ultrasonic coating method to coat dopamine on the substrate surface. Through the analysis of SEM, AFM and contact angle instrument compared of the material surface morphology and the change of hydrophilicity using the different method.2. With polystyrene and stainless steel as base material,respectively, this paper studied the effects of p H, concentration of dopamine, reaction temperature, reaction time, ultrasonic power on the coating of dopamine in ultrasonic condition.3. Using gamma ray radiation as radiation source, put the dopamine coated stainless steel in ethyl methacrylate(HEMA) aqueous solution to copolymerization. This paper studied the effects of HEMA concentration, inhibitor concentration on the grafting progress. Infrared spectroscopy(ATR-FTIR), XPS, contact angle measurement, SEM,AFM were used to study the chemical structure, surface element, surface morphology and hydrophilicity of stainless steel surface before and after dopamine coating and radiation grafting HEMA.4. The determination of polarization curve electrochemical workstation, platelet adhesion test, hemolysis test and protein adsorption experiments were investigated the corrosion resistance, biocompatibility of the surface of pristine stainless steel, dopamine coated stainless steel and HEMA grafted onto the dopamine coated stainless steel stainless steel coated stainless steel.