Synthesis and crystallization of hybrid spherical colloids composed of polystyrene cores and silica shells
Synthesis and crystallization of hybrid spherical colloids composed of polystyrene cores and silica shells
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DOI：
10.1021/la036245h
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发表时间：
2004-04-13
期刊：
影响因子：
3.9
通讯作者：
Xia, YN
中科院分区：
文献类型：
--
作者：
Lu, Y;McLellan, J;Xia, YN
采用Stober法在单分散聚苯乙烯微球表面包覆均匀的二氧化硅壳层，制备了核壳杂化粒子。直径在0.1-1.0 μ m范围内的聚苯乙烯珠粒已被成功地证明可用于该工艺，并且二氧化硅涂层的厚度可通过调节四乙氧基硅烷的浓度、沉积时间或两者来控制在50-150 nm的范围内。沉积的二氧化硅的形态和表面光滑度被发现强烈依赖于一些参数，如聚合物珠上的表面官能团，介质的pH值，和沉积时间。由二氧化硅制成的空心球可以通过在高温下在空气中煅烧或通过用甲苯进行湿法蚀刻来选择性地去除聚合物核而获得。这些核-壳胶体也被探索作为构建块来制造长程有序晶格（或胶体晶体），其表现出不同于由纯聚苯乙烯或二氧化硅制成的球形胶体组装的阻带。
The Stober 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 mum 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.