摘要
采用二溴异丁基酯化低聚乙二醇甲基丙烯酸酯(OEGMA-Br)为自引发性单体,以三(2-苯基吡啶)合铱为光氧化还原催化剂,通过激光调控自缩合表面引发原子转移自由基聚合(SI-ATRP),在硅片表面制备超支化聚乙二醇(PEG)聚合物刷.在对硅片-溶液界面与硅片表面溶液中自引发性单体OEGMA-Br自缩合ATRP反应机理推导的基础上,硅片表面反应溶液的核磁共振(1H-NMR)表征及聚合物刷表面活性末端官能团的光电子能谱(XPS)表征证实了所得表面PEG聚合物刷的超支化结构;椭圆偏光仪对不同反应条件下聚合物刷厚度的表征表明过高或过低的自引发性单体浓度均不利于超支化PEG聚合物刷的生长,同时其生长过程受到聚合时间和光辐照强度的影响;采用异硫氰酸荧光素(FITC)标记牛血清蛋白表面吸附实验证明PEG聚合物刷微图案的非特异性抗蛋白吸附性能.
Surface polymer brushes have been extensively studied to modify the surface properties of substrates and to implement multifunctionality. Compared to comb type brushes, hyperbranched-structure polymer brushes show significant advantages in thermal stability, compatibility and functionalization potential. The preparation study of surface hyperbranched polymer brushes is fundamental to explode polymer brushes applications. Here, laser-mediated surface-initiated atom transfer radical polymerization （SI-ATRP） is firstly introduced to conduct self-condensing polymerization, with 2-bromoisobutyrate ester of oligo （ethylene glycol） methacrylate （OEGMA- Br） as AB＊-type inimer and Ir（ppy）3 as the photo-redox catalyst, to prepare hyperbranched poly（ethylene glycol）（PEG） brushes on a silicon substrate. Based on the discussion on the mechanism of OEGMA-Br inimer self-condensing polymerization on solid-liquid interface and at surface solution on silicon surface, five microstructures are proposed for the constitution of the hyperbranched PEG brushes and the corresponding signals are further confirmed by 1H-NMR spectra analysis. X-ray photoelectron spectroscopy （XPS） characterization is conducted to investigate the chemical composition of hyperbranched PEG brushes. The high resolution C 1 s and Br3d spectra indicate the preservation of surface bromine density on hyperbranched PEG brushes in comparison to initiator surface on silicon substrate, implying the hyperbranched microstructure and high active site densities. Then, the thickness of hyperbranched PEG brushes corresponding to different inimer concentrations is investigated by ellipsometry, which indicates an increase first in the thickness and a subsequant decrease trend as the inimer concentration increased. A competitive mechanism for the surface polymerization is proposed to depict the growth of the hyperbranched PEG brushes on a silicon substrate, which refers to a competition between the solid-liquid interface polymerization and the surfa
作者
马康
马玉录
赵海利
刘嵩
谢林生
沙金
Kang Ma, Yu-lu Ma, Hai-li Zhao, Song Liu, Lin-sheng Xie, Jin Sha(Engineering Center of Efficient Green Process Equipment and Energy Conservation of Ministry of Education, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 20023)
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2018年第5期571-580,共10页
Acta Polymerica Sinica
基金
国家自然科学青年基金(基金号51503065)资助项目
关键词
表面引发原子转移自由基聚合
超支化结构
聚乙二醇刷
微图案
Surface-initiated atom transfer radical polymerization
Hyperbranched structure
Poly（ethyleneglycol） brush
Micropattern
