Structural Regulation And Preparation Strategies Of Hydrophilic Polymer Coatings

Hydrophilic polymer coating materials can provide super-lubricity and super-wetting to traditional solid surfaces and can bring advanced functions such as anticoagulation,drug loading,and improved biocompatibility to the biomedical field.However,hydrophilic polymer coating materials generally face the problems of harsh preparation conditions,poor generalizability,and weak interfacial adhesion,which limit the application prospects of such materials.Therefore,the development of environmentally friendly,easy-to-operate,low-toxicity,and highly versatile coating preparation strategy has significant basic research value and application prospect.This thesis mainly studies two types of hydrophilic polymer coating materials,hydrogel and polymer brush.On the one hand,tough hydrogel paint is prepared under green and mild conditions by introducing double network structure enhancement strategy.On the other hand,argon plasma surface treatment technology is used to develop a universal strategy covering a variety of hydrophilic polymer brush coatings.And the advantages of the two technologies in medical devices and outdoor wearable devices are explored respectively.The specific research contents are as follows:（1）Preparation of"Tough Hydrogel Paint"based on silane coupling agent.Different from the traditional in-situ polymerization to prepare hydrogel coating,in this experiment,the polymerization,crosslinking and interlinking of hydrogel coating are controllably separated based on the minimum crosslinking degree of silane coupling agent at p H～4.5.Tough hydrogel paint is obtained by introducing calcium alginate as an energy dissipating structure in polyacrylamide（PAAm）hydrogel paint systems.The viscosity of the tough hydrogel paint is regulated by regulating the concentration of the first network AAm monomer and chain transfer agent（CTA）.The experimental results showed that the prepared tough hydrogel paint can be coated on the solid surface of various materials and complex morphology by brushing,coating,dipping and other ways.In addition,the mechanical properties test shows that the shelf life of the tough hydrogel paint can be up to one month at room temperature,and it can last longer at low temperature.The curing time can be adjusted from days to hours and the elastic modulus can be increased to～500 k Pa by adjusting the p H and concentration of the alkaline calcium chloride solution.The adhesion energy between tough hydrogel paint and substrate is>1400 J m^-2 by peeling test.In the application exploration,the mechanical properties of the medical gloves coated with tough hydrogel paint and the original medical gloves were tested.The comparison shows that the toughness value of the medical gloves coated with tough hydrogel paint is as high as 3.2 MJ m^-2,which is 3.2 times that of the original medical gloves,so the medical gloves coated with tough hydrogel paint can reduce the rate of being scratched by sharp objects.Through high-speed video,we observe the state change of original balloon and balloon coated with tough hydrogel paint when it meets sharp objects.When the needle pricks uncoated balloon,the balloon bursts immediately when the needle touches the balloon;when the balloon coated with tough hydrogel paint is pricked with a sharp needle,the balloon maintains the integrity of the original shape without bursting,and the balloon remains intact even after the needle is pulled out.Therefore,the tough hydrogel paint has the potential application value of anti-bursting in medical airbag and other equipment.（2）Preparation of multifunctional hydrophilic polymer brush coating.The polymer brush can be successfully grafted from the solid surface by immersing the argon plasma-treated solid surface in an aqueous solution containing only monomers（without introducing various substances such as initiators）.During the experiment,a variety of monomers are grafted from the solid surface,and the contact angle of water on PS surface is measured by Contact Angle Meter.The change of the contact angle from hydrophobic state（98°）to hydrophilic state（～10°）proved that the hydrophilic polymer brush coating prepared by argon plasma method is universal.It is proved by infrared spectrum test that the polymer brush is successfully grafted on the solid surface.Combined with SEM and AFM experimental results,we confirm the solid surface morphology and the thickness of the grafted polymer brush before and after grafting.Through the UV-Vis spectrophotometer test,it is found that the PS surface always maintained high transparency（>90%）before and after grafting.By culturing human renal epithelial cells on the surface of PS grafted polymer brush,the cells maintain a high survival rate（>90%）within 24 hours,indicating that the surface of the grafted polymer brush has high biocompatibility.In addition,the transfusion catheter grafted with zwitterionic（SBMA）polymer brushes by this method has a good anticoagulant effect（>30 min）,which exceeds the existing reported results（10 min）.In summary,the research on hydrophilic polymer coating materials will provide material basis and innovative ideas for our applications in various fields.