Sappl Lisa, Likos Christos N, Zöttl Andreas
Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria.
Macromolecules. 2024 Dec 4;57(24):11534-11549. doi: 10.1021/acs.macromol.4c01656. eCollection 2024 Dec 24.
We employ mesoscopic simulations to study the thermophoretic motion of polymers in a solvent via multiparticle collision dynamics (MPCD). As the usual solvent-monomer collision rules employed in MPCD involving polymers fail to cause thermophoresis, we extend the technique by introducing explicit solvent-monomer interactions, while the solvent molecules remain ideal with respect to one another. We find that with purely repulsive polymer-solvent interaction, the polymer exhibits thermophilic behavior, whereas to display thermophobic behavior, the polymer-solvent potential requires the presence of attractions between solvent particles and monomers, in accordance with previous experimental findings. In addition, we observe that the thermophoretic mobility is independent of polymer length in the observed regime, again in agreement with experiments. Finally, we investigate the thermophoretic behavior of block copolymers, demonstrating that the thermophoretic mobility can be obtained by linear interpolation, weighted by the relative lengths of the two blocks.
我们采用介观模拟，通过多粒子碰撞动力学（MPCD）来研究聚合物在溶剂中的热泳运动。由于MPCD中涉及聚合物的常规溶剂 - 单体碰撞规则无法引起热泳现象，我们通过引入明确的溶剂 - 单体相互作用来扩展该技术，而溶剂分子彼此之间仍保持理想状态。我们发现，在聚合物 - 溶剂相互作用纯粹为排斥力时，聚合物表现出嗜热行为，而要表现出憎热行为，聚合物 - 溶剂势需要溶剂粒子和单体之间存在吸引力，这与先前的实验结果一致。此外，我们观察到在所观察的范围内，热泳迁移率与聚合物长度无关，这也与实验相符。最后，我们研究了嵌段共聚物的热泳行为，证明热泳迁移率可以通过线性插值获得，权重为两个嵌段的相对长度。
