长棒状T形三组分双亲分子相行为的耗散粒子动力学模拟

摘要

Using dissipative particle dynamics simulations, a phase diagram in terms of temperature and lateral chain length was established, related structural parameters and the effective volume fraction of lateral chains fL related to each mesophase were calculated. The experimentally observed pentagonal, hexagonal co-lumnar phase and the lamellar phase where rods are stacked with in-plane order are firstly reproduced. The re-sults show that the phase sequence and structures in the diagram of T-shaped ternary amphiphilies with long rod-like mesogens agree well with previous reports, the effective volume fraction of lateral chains fL related to each mesophase is also quantitatively consistent with the experimental value. These combined results demon-strate that the coarse graining model in our simulation reflects essential structural features of T-shaped real mo-lecules like molecular topology, excluded volume effects, tendency to phase separation, the length-to-width ra-tio of rod liquid crystal unit and the spatial effects of lateral chains, and they also confirm the fact that the size of lateral chains plays an important role in affecting the self-assembled structures of nonlinear systems and the distribution of each constituent.%采用耗散粒子动力学方法建立了以侧链长度和温度为变量的相图，计算了相关结构参数及每个液晶相对应侧链的有效体积分数，重现了实验上观察到的五边形、六边形柱状相及刚棒在层内位置的有序堆垛层状结构。研究发现，长棒状T形三组分双亲分子相图中的相序列和相结构符合相关报道，并且侧链有效体积分数fL与实验值一致。表明粗粒化模型反映了真实T形分子的主要特性，如分子的拓扑结构、排除体积效应及分相趋势、刚棒液晶基元的长径比和侧链的空间效应。证实了侧链尺寸对主/侧链非线性连接体系的自组装结构及各组成单元的位置分布的重要作用。