Lu Yu, McLellan Joe, Xia Younan
Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, USA.
Langmuir. 2004 Apr 13;20(8):3464-70.
The Stöber method has been adopted to prepare hybrid core-shell particles by coating the surfaces of monodisperse polystyrene beads with uniform silica shells. Polystyrene beads with diameters in the range of 0.1-1.0 microm have been successfully demonstrated for use with this process, and the thickness of the silica coating could be controlled in the range of 50-150 nm by adjusting the concentration of tetraethoxysilane, the deposition time, or both. The morphology and surface smoothness of the deposited silica were found to strongly depend on a number of parameters such as the surface functional groups on the polymer beads, the pH value of the medium, and the deposition time. Hollow spheres made of silica could be obtained by selectively removing the polymer cores via calcination in air at an elevated temperature or by wet etching with toluene. These core-shell colloids were also explored as building blocks to fabricate long-range ordered lattices (or colloidal crystals) that exhibited stop bands different from those assembled from spherical colloids purely made of either polystyrene or silica.
采用施托伯方法，通过用均匀的二氧化硅壳包覆单分散聚苯乙烯珠粒的表面来制备核壳杂化颗粒。直径在0.1 - 1.0微米范围内的聚苯乙烯珠粒已成功证明可用于此工艺，通过调节四乙氧基硅烷的浓度、沉积时间或两者，二氧化硅涂层的厚度可控制在50 - 150纳米范围内。发现沉积二氧化硅的形态和表面光滑度强烈依赖于许多参数，如聚合物珠粒上的表面官能团、介质的pH值和沉积时间。通过在高温下于空气中煅烧或用甲苯进行湿蚀刻选择性地去除聚合物核，可以获得由二氧化硅制成的空心球。这些核壳胶体也被用作构建块来制造长程有序晶格（或胶体晶体），这些晶格表现出与由纯聚苯乙烯或二氧化硅制成的球形胶体组装而成的晶格不同的禁带。
