标题： 胶体超粒子的屈曲控制 显示英文标题

标题： Control of Buckling of Colloidal Supraparticles

摘要： 由胶体粒子组成的聚集体，通常称为超粒子，比它们所由的单个粒子具有更多的功能。 由于这些功能由超粒子内初级粒子的排列决定，控制结构形成过程具有根本的重要性。 在这里，我们展示了屈曲如何由粒子-表面活性剂相互作用决定，以及如何通过在时间上操控这些相互作用来控制形成的超粒子的最终形态。 我们使用水/油乳液作为模板来引导超粒子的形成，并通过水滴中的局部pH值来调节带负电荷的胶体粒子与稳定水/油界面的表面活性剂之间的相互作用。 在低pH条件下，表面活性剂的阴离子头部基团质子化会降低粒子的静电排斥，促进界面吸附，并随后引起屈曲。 我们表明，在组装过程中，水相的局部pH值持续变化。 我们通过确定界面吸附被启用的时间点来控制形成路径，我们通过初始pH值来控制这一点。 因此，最终的超粒子形态可以随意定制，从完全屈曲的结构，经过波浪形表面形态，到球形粗糙和球形光滑的超粒子以及晶体胶体簇。 显示英文摘要

摘要： Clusters of colloidal particles, often termed supraparticles, can provide more functionality than the individual particles they consist of. Since these functionalities are determined by the arrangement of the primary particles within a supraparticle, controlling the structure formation process is of fundamental importance. Here, we show how buckling is determined by particle-surfactant interactions and how the final morphology of the formed supraparticles can be controlled by manipulating these interactions in time. We use water/oil emulsions to template supraparticle formation and tailor the interactions of negatively charged colloidal particles with the surfactants stabilizing the water/oil-interface via the local pH within the aqueous droplet. At low pH, protonation of the anionic headgroup of the surfactant decreases electrostatic repulsion of the particles, facilitates interfacial adsorption, and subsequently causes buckling. We show that the local pH of the aqueous phase continuously changes during the assembly process. We gain control over the formation pathway by determining the point in time when interfacial adsorption is enabled, which we control via the initial pH. As a consequence, the final supraparticle morphology can be tailored at will, from fully buckled structures, via undulated surface morphologies to spherically rough and spherically smooth supraparticles and crystalline colloidal clusters.