梳状形状的高聚梳在二氧化硅纳米颗粒的表面上毕业论文外文翻译.doc

Macromolecules Communications to the Editor Volume 38, Number 26 December 27, 2005 ? Copyright 2005 by the American Chemical Society Comb-Coil Polymer Brushes on the Surface of Silica Nan particles Handing Zhao,* Xiao Kang, and Li Leakey Laboratory of Functional Polymer Materials, Ministry of Education, Department of Chemistry, Nankai University, Tianjin 300071, P. R. China Received August 17, 2005Revised Manuscript Received November 4, 2005During the past decade, surface modification of inorganic Nan particles by attachment of polymer brushes has attracted much interest due to the improvement of the properties of the Nan particles, especially the dispersion and stability of the particles in various solvents. Recently, many groups reported preparation of polymer brushes on the surface of gold nanoparticles,1magneticnanoparticles,2and silica nanoparticles.3There are two principal techniques to graft polymer brushes on the surface of the inorganic particles: (1) the “grafting to” method, where the end-functionalized polymers react with the functional groups on the inorganic particle surface, and (2) the “grafting from” method, where the polymer chains grow from the initiator-modified inorganic particle surface. Because of the satiric hindrance imposed by the grafted polymer chains, it is difficult to prepare polymer brushes with high graft density on the particle surface using the “grafting to” method. How-ever, in the “grafting from” method polymer chains grow from the initiators that have been initially anchored to the particle surface, and the grafted chains will not hinder the diffusion of the small molecular monomers to the reaction sites, so the polymer brushes with higher graft density can be obtained. In recent years, there have been increasing research activities in the use of various polymerization methods to grow polymer chains on the silica particle surface. These methods include anionic polymerization,3bcat-Ni ionic polymerization,3dring-opening polymeriz