Development And Applications Of Antifouling Functional Coatings Based On Polyvinylpyrrolidone

Biofouling means the detrimental adhesion of bio-foulants such as biomolecules,microorganisms,and cells on the surface of materials,and it has become a general problem in many fields including optical lenses,medical equipment,and marine equipment.PVP is a hydrophilic and neutrally charged polymer,it can strongly bound water molecules and can form a hydrated layer when coated on surfaces.Therefore,PVP coating can effectively eliminate the electrostatic and hydrophobic forces between bio-foulants and the surfaces.Based on this property of PVP,in this thesis,several antifouling coatings were developed and systematically characterized,and their applications in endoscope protection,medical antifouling catheters,and marine antifouling coatings were explored.The main contents of this thesis are as follows:Firstly,aiming at equipment malfunction caused by fogging or microbial adhesion on the surface of optical lens,a P(NVP-co-MA)polymer was developed.This co-polymer can be grafted to the glass surface to form a stable hydrophilic antifouling coating in a mild reaction condition.Due to the hydrophilic PVP,tiny water droplets can spread on the surface to form a water film and fog formation can be avoided.The modified glass maintains a light transmittance >88% in the fog test,and can effectively resist bacteria adhesion(> 99%).It also shows an excellent self-cleaning performance against hydrophobic contaminants.Next,this thesis focuses on the antifouling modification of the medical catheter inner wall.Combining the antifouling property of PVP and the low surface energy of PDMS,a new amphiphilic polymer PDMS-PVP is designed and prepared.This polymer can be easily incorporated into the catheter inner wall with a simple immersion method to form a highly effective antifouling coating.This method may notably improve current modification methods which are complex and time consuming.Besides medical coatings,the prevention of biofouling in marine engineering field is also a major challenge.In this thesis,PVP is modified to directly crosslink with PDMS at room temperature to form a chemically stable amphiphilic marine antifouling coating.The coating can effectively inhibit the adhesion of bacteria and diatoms(both >99%),and reduce the adhesion of barnacles(reduction rate >82%).Next,the effect of the amphiphilic polymer PDMS-PVP raw material ratio and polymer molecular weight on the resistance to marine biofouling are systematically studied.Diatom and barnacle tests show that the coating possesses surface renewable and antifouling properties,and the antifouling performance was proportional to the PVP content.The marine field test(? 4 months)proves that the coating based on 10%of PDMS-PVP content presents the optimized antifouling properties.In summary,basing on the antifouling property of the hydrophilic PVP polymer,this thesis focuses on the development of highly effective,stable,environmentally friendly antifouling coatings using straightforward methods in various fields of biochemical engineering.The work presented in this thesis may provide new opportunities for the development of novel antifouling coatings.