Wu Gaoxiang, Cho Hyesung, Wood Derek A, Dinsmore Anthony D, Yang Shu
Department of Materials Science and Engineering, University of Pennsylvania , 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States.
Department of Physics, University of Massachusetts Amherst , Hasbrouck Lab, 666 North Pleasant Street, Amherst, Massachusetts 01003, United States.
J Am Chem Soc. 2017 Apr 12;139(14):5095-5101. doi: 10.1021/jacs.6b12975. Epub 2017 Apr 3.
We investigate the microconfinement of charged silica nanoparticles dispersed in refractive index matching monomers in poly(dimethylsiloxane) (PDMS) porous membrane. Here, the silica colloidal particles interact with each other and the pore wall via electrostatic double layer forces. Different from the hard sphere systems where the assembled morphologies are prescribed by the diameter ratio between the cylindrical confinement and the nanoparticles, here we observe a much richer variety of assemblies that are highly sensitive to both bulk and local nanoparticle concentration with fixed particle size and channel size. The experimentally observed assembly morphologies are consistent with theoretical predictions from the literature, based on Yukawa potential in the low packing density regime. Also, most of the configurations found in the experiment are well described by computer simulations using pairwise additive long-range repulsive interactions, demonstrating the ability to control the system to obtain a desired structure.
我们研究了分散在聚二甲基硅氧烷（PDMS）多孔膜中折射率匹配单体中的带电二氧化硅纳米颗粒的微限域效应。在这里，二氧化硅胶体颗粒通过静电双层力相互作用以及与孔壁相互作用。与硬球体系不同，在硬球体系中组装形态由圆柱形限域与纳米颗粒之间的直径比规定，而在此我们观察到种类丰富得多的组装结构，这些结构对于固定粒径和通道尺寸下的本体和局部纳米颗粒浓度高度敏感。实验观察到的组装形态与基于文献中低堆积密度区域的汤川势的理论预测一致。此外，实验中发现的大多数构型都可以通过使用成对加性长程排斥相互作用的计算机模拟很好地描述，这证明了控制该系统以获得所需结构的能力。
