毛细微模塑实现单链微球的有序排列

以微米级的聚苯乙烯微球当作真实大分子链的结构单元,用软刻蚀的毛细微模塑法在玻璃基片上把它们组装成单链形状的微球串,加热使微球相互连接,从而为“亚观”尺度上模拟“大分子”链(刚性链)提供简单又直观的“模型”．并把基片上的模型链剥离下来,处于自由态．

Ordered Arrangement of Micro-beads in Single Line by Micromolding in Capillaries

An effective procedure was demonstrated to arrange spherical micro-beads into ordered, long, line-shape arrays by means of "micromolding in capillaries" in soft lithography. Polystyrene (PS) micro-beads with 2-3 mm of diameter were used as units and arranged by molding in continuous micro-channels formed by the conformal contact between a glass substrate and an elastomeric stamp with micrometer-scale line patterns on the surface. An aqueous emulsion of PS micro-beads filled these channels by capillary action and was allowed to solidify. The stamp was then removed. The PS micro-beads could be assembled into a string of long line-shape arrays, and the strings were then joined by heating them to their softening temperature. In order to separate the PS micro-bead string from the substrate, the glass was covered with a thin layer of Al or polymethyl methacrylate. After the Al layer was dissolved, the string of PS micro-beads would be released. A string of micrometer scale PS beads can be used as a simple and direct "model" of a real macromolecular chain. It is hopeful to show an analogue with the condensed process of real macromolecules in a mesoscopic scale using the "string of PS micro-beads".