Study And Applications Of Antifouling And Humidity-responsive Properties Of Hydrophilic Polymers

Hydrophilic polymers with abundant hydrophilic groups have been widely used in many fields such as biomedicine,marine antifouling,wastewater treatment and intelligent materials.This thesis focuses on the systematic study of a variety of hydrophilic polymers,and their applications in the fields of anti-biofouling and intelligently humidity-responsive materials.The main contents of this thesis are as follows:Zwitterionic polymers possess strong hydrophilicity,excellent anti-bioadhesion and biocompatibility,etc.However,the differences of different zwitterionic materials have not been well studied.In this thesis,hydrogels based on four typical types of zwitterionic monomers were synthesized by crosslinking polymerization.In this way,the physicochemical and biological properties of different zwitterionic materials could be systematically studied and compared.This study provides useful in formations for the selection of zwitterionic materials in biomedical applications.Meanwhile,hydrogels based on six nonionic hydrophilic monomers were synthesized and their physicochemical and biological properties were systematically studied and compared.It was found that polypyrrolidone(PVP)possessed the strongest hydration and antifouling properties.Therefore,a copolymer(PNMBH)was designed and synthesized using PVP as the main segment of copolymer chain.Then,PNMMB was integrated into polydimethylsilicone(PDMS)network,and an amphiphilic PNMBH-PDMS antifouling coating with dual functions was prepared.Antifouling performances of the antifouling coating were evaluated.Moreover,a four-month marine field test showed the long-term and strong antifouling performance of this coating,indicating its promising application in marine industry.In this thesis,a variety of hydrophilic polymer materials were also selected to cast films.Agarose(AG)and sodium hyaluronate(SH)with best film-forming properties were selected and their humidity-responsive performance was evaluated.Then,a humidity-driven soft robot was designed and prepared with AG film,which could perform spontaneous and continuous fast rolling locomotion.The rolling speed of the Hydrollbot could be up to 0.714 BL/s on a wet substrate with a constant humidity(70% RH),and its trajectory could be programmable by changing the shapes of AG film.Next,SH and multi-walled carbon nanotubes(MWCNT)were combined to prepare a humidityresponsive composite film as a humidity sensor.This sensor possessed high sensitivity,accuracy,stability and low hysteresis.It could be used for breath monitoring,and the response/recovery time under rapid breathing could reach to 0.4 s/ 0.3 s.This sensor could also efficiently detect finger humidity and could be applied to non-contact switches.These studies provided a new way for the application of hydrophilic polymers in the field of intelligent humidity-responsive driving and humidity-responsive sensing.