Design Synthesis And Applications Of Y-shaped Unctional Molecules In Surface Modification Of Materials

Grafting polymer brushes on the surface of materials is a common method of surface modification.Compared with other types of polymer brushes,Y-shape mixed polymer brushes are mainly characterized in that two molecular chains are grafted on the surface of the material through a common,single anchoring group,so a uniformly distributed mixed polymer brush can be obtained.In this paper,two different Y-shape functional initiators are designed and synthesized,and research for their applications in surface modification of materials.(1)Firstly,we synthesized a new catechol-based biomimetic Y-shaped binary photoinitiator(Y-photoinitiator).Its "leg" is a catechol functional anchoring moiety capable of bonding to the surface of materials.The arms are photoinitiator moieties that can initiate the polymerization of vinyl monomers by ultraviolet and visible light irradiation,respectively.Then,based on the synthesized Y-photoinitiator,Styrene(St)and N-vinylpyrrolidone(NVP)were used as model monomers and its applications for gold surface modification with Y-shaped block copolymer brushes poly(N-vinylpyrrolidone)-block-poly(styrene)(PVP-b-PS)through both "grafting to" and"grafting from" strategies.The modified surface exhibits different surface wettability and surface morphology in different selective solvents.Finally,we also prepared a block copolymer modified gold surface(Au-g-PILPNG-RGD)containing poly(ionic liquid)and short peptide RGD through the "Grafting from" strategy.The Au-g-PILPNG-RGD surfaces showed excellent cell-adhesive,bacteriostatic,and bactericidal properties.(2)After that,in order to conveniently and fastly construct multifunctional biological material surface interface,a new Y-shape functional molecule containing benzophenone group(Y-photoclick)was designed and synthesized.The "leg" of the Y compound consists of a benzophenone group as surface anchoring moiety.And one"arm" is photoinitiator moiety containing alkyl bromide,which can initiate the polymerization of vinyl monomers by ultraviolet irradiation;the other "arm" is sulfonyl fluoride functional group can be grafted with different functional molecules through the"sulfur(Ⅵ)-fluorine exchange"(SuFEx)click reaction.Based on the synthesized Y-photoclick,under the UV light irradiation,three different functional material surfaces were successfully prepared by the“one-pot”method:(a)Material surfaces containing poly(hydroxyethyl methacrylate)and ionic liquid(Si-g-PHEMA-IL),the Si-g-PHEMA-IL surface showed excellent bacteriostatic,and bactericidal properties.(b)Material surfaces containing poly(glucosamine)and poly(ethylene glycol)(Si-g-(PHEMA-co-PMAG)-PEG5000),the Si-g-(PHEMA-co-PMAG)-PEG5000 surface has a good performance of repelling non-specific protein adsorption and specific ConA adsorption.(c)The material surface containing GRGDY short peptide and poly(vinylpyrrolidone)(Si-g-(PHEMA-co-PVP)-GRGDY),which has a good performance of repelling the non-specific protein adsorption on the surface of the material and promoting the adhesion of L929 cells.