带电悬浮粒子胶体晶体的固定化

采用光固化技术, 以丙烯酰胺单体与亚甲基双丙烯酰胺交联剂在紫外光的照射下发生光聚合反应, 嵌入聚苯乙烯胶体晶体, 实现了胶体晶体的固定化. 结合反射光谱和Kossel衍射技术研究对照了固定化前后胶体晶体的变化, 实验结果表明, 通过这种水凝胶固定化的胶体晶体保存了未固定前悬浮液中胶体晶体的结构. 但固定化后的胶体晶体的晶面间距和晶体的尺寸都略微减小. 通过对固定化后的水凝胶长时间的反射光谱观测, 发现固定化后胶体晶体在Milli-Q水中起初会发生溶胀, 经过2-5天溶胀-消溶胀过程达到平衡, 平衡后的水凝胶胶体晶体十分稳定, 可以长时间保持胶体晶体的结构. 因此, 胶体晶体固定化不但极大地提高了悬浮液中胶体晶体的抗剪切能力, 还克服了悬浮液中胶体晶体对离子、外界干扰的敏感性, 扩大了胶体晶体的实际应用价值.

Immobilization of Charged Colloidal Crystals in a Polymer Matrix

We immobilized colloidal crystals of charged particles in a poly (acrylamide) matrix by photoinduced polymerization. A reflection spectrum and Kossel-line diffraction were employed to trace and compare changes in the colloidal crystal structure before and after immobilization processing. Our experiments showed that immobilized colloidal crystals successfully retained the structure of colloidal crystals unless the sizes and the lattice spacings of the immobilized colloidal crystals decreased slightly. By observing the structure of immobilized crystals in Milli-Q water we confirmed that the lattice spacings of the crystals varied for several days initially during immobilization because of gel swelling or de-swelling. After reaching a balance (2-5 d), the immobilized colloidal crystals are found to be stable in Milli-Q water. Our study thus explores potential applications of colloidal crystals such as their use in photonic materials.