A Preliminary Study On The Construction And Application Of A New Controllable Polymer Coating

Polydopamine（PDA）has been established as the most effective and powerful universal coating,which is used in the fields of chemistry,physics,medicine and engineering.However,some major challenges,such as low mechanical strength and poor wear resistance,still limits its in-depth applications.Even small changes in environment,e.g.,ultrasonic waves,acid solutions,may result in peeling off of the coating.In addition,the PDA-coated surface displays a dark and oily colored background.Herein,we report a universal coating made from bis（vinylsulfonyl）methane（BVS）on a variety of substrate surfaces,e.g.,metals,metal oxides and polymers.It has the following advantages:controllability of film formation,broad-spectrum of substrate surfaces and possibility of further functionalization.It also offers good stability and colorless background.In this thesis,firstly,the controllability of the reaction and the subsequent reactivity were examined.The coating was successfully constructed through oxygen plasma treatment and BVS coupling reaction utilizing the surface of silicon wafers.The controllability,characterized using static water contact angle and ellipsometer,showed that the thickness of the coating is a function of time and catalyst.After 12 hours of reaction,the film thickness has reached 60 nm,which is higher than the reported maximum thickness（50 nm）of PDA coating.Sulfo-Cy3-NH₂,a fluorescent dye,was also used to verify the subsequent reactivity of the surface.Then,the substrate surfaces and the coating stability were studied.The BVS coatings were successfully constructed on metals（titanium,gold,steel）,metal oxides（alumina）,inorganic non-metals（silicon,glass）and polymers（polypropylene,polytetrafluoroethylene）.In addition,the BVS coating has good mechanical stability under ultrasonic conditions,acid solution treatment and high-pressure steam sterilization conditions.Interestingly,subsequent reactivity still remains.Finally,the effect of BVS coating on cell growth was preliminarily evaluated.Using fluorescence image analysis of the titanium surface with PDA or BVS coatings,the adhesion area of the mammalian cells（NIH 3T3）and their nucleus were quantified.After 1 day of culture,it can be observed that the cell survival rates of the BVS and PDA coated titanium surface are59.4%and 36.5%,respectively.Compared with the first day culture,the cell proliferation after48 h on the BVS and PDA coated surface were 10.6 and 8.0 times higher,respectively.The above results indicate that our BVS coating promotes cell adhesion and proliferation,better than PDA coating.