Nano-sized Spherical Polyelectrolyte Brushes: Preparation,Characterization and Potential Applications
Nano-sized spherical polyelectrolyte brushes were prepared by two novel methods: Thermal-controlled emulsion polymerization and photo-emulsion polymerization. The brush particles consist of a solid polystyrene core and a poly(acrylic acid) (PAA) shell which are covalently attached on the core surface densely by one end.The preparation was divided into three steps: First of all, the core was synthesized by conventional emulsion polymerization initiated by redoxy initiators. Then, the home-made thermo-initiators or photo-initiators were attached to the core surface by controlled emulsion polymerization. Finally, the acrylic acids dissolved in water were polymerized under controlled heating or UV radiation, and the PAA brush shell was grown in-situ on the core surface. Dynamic light scattering (DLS) was employed to determine the size of the brushes and to monitor the brush growing during the preparation. The structure of brushes was observed by Atomic Force Microscopy (AFM) and Transmission Electronic Microscopy (TEM). The size of the spherical polyelectrolyte brushes was tunable by controlling pH and salt concentration in the solution while the pH and salt concentration inside the brush less changed due to the intensified Donnen effect of PAA brushes. The thickness of brushes can be modulated by the amount of acrylic acid, and the grafting density of PAA on the core surface is tunable by the amount of themo-initiators or photo-initiators. These nano-sized spherical polyelectrolyte brushes should be ideal candidates for removal of harmful heavy metal ions in waste water, recovery of precious metals in dilute aqueous solutions, and carriers for proteins, diagnostic groups or nano-sized metal catalysts.
Spherical polyelectrolyte brush dynamic light scattering thermo-controlled emulsion polymerization photo-emulsion polymerization
Xuhong Guo Li Li Xiang Wang Jun Xu Shuang Wu Qingchuan Chen Shibin Huang
State Key Laboratory of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China
国际会议
5th International Symposium on High-Tech Polymer Materials(HTPM-V)(第五届国际高技术高分子材料学术会议)
北京
英文
115
2008-10-27（万方平台首次上网日期，不代表论文的发表时间）