凹陷状胶体粒子的自组装  

The self-assembly of the concave particles

作　　者：程志峰[1] 罗富华 

机构地区：[1]固体微结构国家实验室,南京大学物理学院,南京210093 [2]苏州大学软凝聚态物理及交叉研究中心,苏州215006

出　　处：《南京大学学报（自然科学版）》2014年第1期23-29,共7页Journal of Nanjing University（Natural Science）

基　　金：国家自然科学基金(91027040);苏州大学引进人才启动基金(Q410800510)

摘　　要：凹陷状胶体粒子的自组装具有独特的方向性和形状识别性,是最近几年自组装研究的热点问题之一.由于缺乏合适的实验模型系统,至今为止,大部分研究都是以计算机模拟为主.为了从实验上研究凹陷状胶体粒子的自组装现象,本文首次采用分散聚合的方法,设计并成功合成了两种单分散性的、具有不同数目凹陷的胶体粒子:单凹陷粒子和多凹陷粒子.通过扫描电镜和光学显微镜对合成的凹陷粒子的形貌、大小进行分析,结果表明所得到的凹陷粒子为大小均一的微米级胶体粒子,表面光滑,在水溶液中能稳定分散,适合利用光学显微镜直观研究胶体凹陷粒子自组装.本文考察了单凹陷胶体粒子的方向性聚集组装和多凹陷粒子的特定识别性自组装现象.我们研究发现,在交变电场中,单凹陷粒子倾向于侧向移动,容易定向自组装成线性结构,使得该粒子在模拟碗状粒子凝聚态物理结构方面具有潜在的应用.另外,本文以多凹陷胶体粒子为"锁",聚苯乙烯圆球为"钥匙",研究了多凹陷粒子与圆球粒子的"锁-钥"自组装现象,展现了圆球粒子与凹陷粒子之间丰富的"锁-钥"自组装可能性,并初步探讨了其形成机制.Recently,there is a growing interest in studying the concave colloidal particles due to their unique directional and shape-recognition assemblies.In order to study this special assembly phenomenon,we creatively used the dispersion polymerization to design and fabricate concave colloidal particles with different number of dimples：the single-dimple colloids and the multi-dimple colloids.With uniform size and smooth surface,these two types of dimpled colloids are ideal model to study the self-assembly of concave particles.In addition we investigated the directed self-assembly of the single-dimple colloids and the specific bonding of the multi-dimple colloids.In an alternating electric field,the single-dimple colloids tend to move in a side-direction way.This special movement＆amp;nbsp;would induce directional self-assemblies between the aggregated particles.Using the multi-dimple colloids as the“lock”particles,and the polystyrene spheres as the“key”particles,the lock-and-key self-assembly by depletion attraction is explored in this article.The results demonstrate a variety of bonding possibilities existing among the multi-dimple particles and spherical particles.Besides,we also discussed formation mechanism of the lock-and-key.

关 键 词：单凹陷粒子 多凹陷粒子 自组装 交变电场 排空力 

分 类 号：O648[理学—物理化学]