活性胶体的个体行为与动态自组装  

Individual behaviors and dynamic self-assembly of active colloids

作　　者：周超[1] 王威[1] 张何朋 ZHOU Chao WANG Wei ZHANG HePeng(Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055, China Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai 200240, China Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China)

机构地区：[1]哈尔滨工业大学深圳研究生院,深圳518055 [2]上海交通大学物理与天文系,上海200240 [3]上海交通大学自然科学研究院,上海200240 [4]人工微结构科学与技术协同创新中心,南京210093

出　　处：《科学通报》2017年第2期194-208,共15页Chinese Science Bulletin

基　　金：国家自然科学基金(11402069;11422427);深圳市孔雀技术创新项目(KQCX20140521144102503);哈尔滨工业大学科研启动基金及杰出人才培育基金;上海高校特聘教授(东方学者)岗位计划(SHDP201301);上海市教委科研创新项目(14ZZ030)资助

摘　　要：近几年,活性物质的研究引起了科学界的高度兴趣,它们能够依靠不断消耗周围的能量实现自驱动,同时使系统处于热力学非平衡态,例如鱼群、鸟群、细菌菌落以及细胞组成的组织等.在这些群体中,个体成员之间可以通过某些简单的规则进行"通讯",进而呈现出有趣且相对复杂的群体行为.长期以来,细菌被用作模型系统以研究个体行为如何导致群体行为.最近,对能够自主运动和动态自组装的人造胶体颗粒的研究快速发展,并且受到了广泛的关注.这类胶体颗粒又被称为微纳米马达,能够自发运动,并且易于制备和功能化,具有良好的均一性,因而能作为细菌的补充,帮助我们更好地研究活性物质.本文综述了活性胶体领域近几年的主要发展,包括自然界中存在的微生物和人造胶体颗粒.在对细菌的研究进行简要介绍后,重点介绍了人造活性胶体颗粒实验方面的进展.首先介绍了几种主流的人造活性胶体体系,并且着重介绍了其驱动机理;随后概述了这些活性胶体颗粒在动态自组装方面的研究进展.活性胶体颗粒之间可以经由化学物质梯度、静电力相互作用、范德华力以及流体力学相互作用等机制,出现成对组装、团簇、群聚以及其他动态行为;最后对本领域未来的发展进行了讨论和展望.In recent years, there is mounting interesting in the study of active matters that self-propel by consuming energy and therefore lie beyond thermal equilibrium. Examples include fish schools, bird flocks, bacteria colonies, and tissues made of live cells, to name a few. Mobility of the individual components of these groups, coupled with communications among group members following some simple rules, often gives rise to fascinating and complex emergent behaviors. At the microscale, bacteria arc often studied as model systems to understand how individual motion leads to collective behaviors. More recently, synthetic colloids that demonstrate autonomous motion and interesting dynamic assembly behaviors have been developed. Owing to their ease of fabrication, uniformity and funetionalizability, these synthetic colloids have attracted much attention in extending our capability in the study of active matters. In this review, we highlight the recent development in the field of active colloids, which include both natural microorganisms as well as synthetic colloids. We begin with a short overview of the research on bacteria. When isolated, bacteria convert nutrients in the environment into directional motion randomized by Brownian motion, at a force scale around pN. A densely populated bacteria bath, however, demonstrate complicated collective behaviors such as swarming and the formation of biofilm. This is mostly attributed to hydrodynamic interaction and volume-exclusion effect at short time scales, while at longer times the chemicals excreted by bacteria start to significantly contribute to inter-bacteria communication. We then turn our attention to synthetic active colloids, especially their experimental aspects. A few popular synthetic systems are first described, focusing on their individual propulsion mechanisms. These include colloids propelled by self-generated gradients, such as self-electrophoresis, self-diffusiophoresis and self-thermophoresis. A few other popular mechanisms are also briefly introduced,

关 键 词：活性胶体 自驱动 自组装 活性物质 群体行为 

分 类 号：O648.1[理学—物理化学]