Li Weibin, Zhang Chen, Lan Ding, Ji Wenjie, Zheng Zhongyu, Wang Yuren
National Microgravity Laboratory, Institute of Mechanics, Chinese Academy of Sciences, 100190 Beijing, China; School of Engineering Science, University of Chinese Academy of Sciences, 100049 Beijing, China.
National Microgravity Laboratory, Institute of Mechanics, Chinese Academy of Sciences, 100190 Beijing, China; School of Engineering Science, University of Chinese Academy of Sciences, 100049 Beijing, China.
J Colloid Interface Sci. 2022 Oct 15;624:370-376. doi: 10.1016/j.jcis.2022.05.114. Epub 2022 May 21.
Self-assembly of colloidal particles enables the versatile fabrication of highly ordered structures and materials for optical, sensing, and other applications. Nevertheless, many traditional assembly processes are inefficient, because there exists an inevitable contradiction between time efficiency and crystalline quality. In this work, we introduce an ultrafast, robust, and scalable approach of imbibition-induced assembly. We assume that the instantaneous solvent imbibition induced by the nanoporous media could direct ultrafast self-assembly of colloidal particles into ordered structures.
Self-assembly of colloidal particles from a droplet on a nanoporous substrate was firstly observed and investigated. A phase diagram of the thickness of the colloidal crystal as a function of the printing speed and the particle volume fraction was presented through systematic experiments.
The nanoporous substrate can induce strong capillary flow that will directthe rapid self-assemblyof particles intocolloidalcrystals. The imbibition-induced assembly was spatially and temporally combined with the meniscus-guided printing approach, and the printing speed can be improved by two orders of magnitude than the traditional evaporative assembly methods. We finally demonstrate an effective and ultrafast approach for assembling colloidal particles into photonic crystals with controllable sizes and shapes on the macroscale.
胶体颗粒的自组装能够实现用于光学、传感及其他应用的高度有序结构和材料的多种制造。然而，许多传统的组装工艺效率低下，因为在时间效率和晶体质量之间存在不可避免的矛盾。在这项工作中，我们引入了一种超快、稳健且可扩展的吸液诱导组装方法。我们假设纳米多孔介质诱导的瞬时溶剂吸液能够将胶体颗粒超快自组装成有序结构。
首先观察并研究了纳米多孔基底上液滴中胶体颗粒的自组装。通过系统实验给出了胶体晶体厚度作为打印速度和颗粒体积分数函数的相图。
纳米多孔基底可诱导强烈的毛细流动，从而将颗粒快速自组装成胶体晶体。吸液诱导组装在空间和时间上与弯月面引导的打印方法相结合，并且打印速度比传统的蒸发组装方法提高了两个数量级。我们最终展示了一种在宏观尺度上将胶体颗粒组装成尺寸和形状可控的光子晶体的有效且超快的方法。
