Sobrino Fernández M, Misko V R, Peeters F M
Departement Fysica, Universiteit Antwerpen, B-2020 Antwerpen, Belgium.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Feb;89(2):022306. doi: 10.1103/PhysRevE.89.022306. Epub 2014 Feb 21.
Janus particles present an important class of building blocks for directional assembly. These are compartmentalized colloids with two different hemispheres. Here, we consider a two-dimensional model of Janus disks consisting of a hydrophobic semicircle and an electro-negatively charged one. Placed in a solution, the hydrophobic sides will attract each other while the charged sides will give rise to a repulsive force. Using molecular dynamics simulations, we study the morphology of these particles when confined in a channel-like environment using a one dimensional harmonic confinement potential. The interest to this system is first of all due to the fact that it could serve as a simple model for membrane formation. Indeed, the recently synthesized new class of artificial amphiphiles, known as Janus dendrimers, were shown to self-assemble in bilayer structures mimicking biological membranes. In turn, Janus particles that combine the amphiphilicity and colloidal rigidity serve as a good model for Janus dendrimers. A variety of ordered membrane-like morphologies are found consisting of single and multiple chain configurations with different orientations of the particles with respect to each other that we summarize in a phase diagram.
双面粒子是用于定向组装的一类重要构建单元。它们是具有两个不同半球的分隔胶体。在此，我们考虑一种由疏水半圆和带负电半圆组成的二维双面盘模型。置于溶液中时，疏水面会相互吸引，而带电面会产生排斥力。我们使用分子动力学模拟，通过一维谐振约束势来研究这些粒子在类似通道的环境中受限的形态。对该系统的关注首先源于它可作为膜形成的一个简单模型这一事实。实际上，最近合成的一类新型人工两亲分子，即所谓的双面树枝状大分子，已被证明能在模拟生物膜的双层结构中自组装。反过来，兼具两亲性和胶体刚性的双面粒子可作为双面树枝状大分子的良好模型。我们发现了多种有序的膜状形态，包括单链和多链构型，粒子彼此之间具有不同的取向，我们将其总结在一个相图中。
