Effects Of "Click" Groups On Surface/Interface

Typical"click"reaction is the Cu(I) catalyzed cyclo-addition reaction between azide and alkyne groups that highly selectively forms 1,2,3-triazole ("click"group) as product. As a convenient and efficient binding method, it has been widely used in biology, medicine and chemical synthesis. The applications of"click"reaction mainly focused on two directions: as chemical binding technique of high efficiency, and interests in the properties of 1,2,3-triazole groups. In this paper, we focus on the latter.The paper can be outlined in three parts:(1) The interaction between"click"group and gold surface and its application in forming polymer brush: 1-Benzyl-4-(bromomethyl)-1H-[1,2,3]-triazole compound was synthesized as a new kind of ATRP initiator by"click"reaction. The structure was characterized by 1H NMR and EI-TOF MS. Kinetics of living free radical polymerization of styrene and methyl methacrylate initiated from 1-benzyl-4-(bromomethyl)-1H-[1,2,3]-triazole were studied. PS-PMMA copolymer was synthesized to verify the living character of the ATRP initiator. 1,2,3-triazole end-functionalized PS in THF solution can self-assembly on the surface of gold to form monolayers.(2) Surface behavior of diblock copolymers containing side"click"groups, including microphase separation and proteins selective adsorption: Poly(styrene-1-chloromethyl-4-vinyl-benzene) was synthesized by RAFT living polymerization and then was modified by azide and successive"click"reaction to form 1,2,3-triazole side groups in the diblock copolymers to obtain a new diblock copolymer (PS-PVBTM). The structures and functionalization efficiency of click reactions were proved by 1H NMR spectra. PS-PVBTM film was formed by being spun cast on the gold surface and was studied by reflection FTIR, XPS, contact angle and AFM images. The results showed that the film was constituted by micelles with PS as core and PVBTM as corona. After annealed at 90 oC, the micelle structure was transferred into donut-like structure with more PS on the surface. SPR technology was used to study the interaction between PS-PVBTM and proteins. It is found that only protein with positive charge can be adsorbed onto the PS-PVBTM film and the quality of protein adsorbed decreased after annealing.(3) Electrospun of diblock copolymer containing"click"groups and its application in nanofibers: PS-PVBTM in DMF was electro-spun under 15 kV, and nanofibers with obvious phase-separation and diameters of about 100 nm were obtained. The surface of the obtained nanofibers was smoothened after being annealed at 90 oC. Polymethacrylic acid can affect the morphology of the spun-casting nanofirbers.