论文标题
聚合物混合物的限制引起的分级和液态液相分离
Confinement-induced fractionation and liquid-liquid phase separation of polymer mixtures
论文作者
论文摘要
由于这些凝聚力在生物系统中起着重要的功能和调节作用，因此通过液液相分离（生物）分子冷凝物的形成已受到越来越多的关注。但是，大多数研究集中于纯系统在块状溶液中的行为，因此忽略了细胞中存在的众多分子之间的限制效应和相互作用。为了促进我们的知识，我们考虑了较长的聚合物物种的单分散和多分散分子量分布，对液滴中的二元聚合物混合物进行了模拟。我们发现，限制诱导聚合物的空间分离，较短的聚合物移至液滴表面。这种分配导致液滴中心中局部聚合物浓度的明显增加，这在多分散系统中更为明显。因此，该系统在平均聚合物浓度下表现出液态液相分离，其中大量系统仍处于单相度状态。
The formation of (bio)molecular condensates via liquid-liquid phase separation in cells has received increasing attention, as these coacervates play important functional and regulatory roles within biological systems. However, the majority of studies focused on the behavior of pure systems in bulk solutions, thus neglecting confinement effects and the interplay between the numerous molecules present in cells. To advance our knowledge, we perform simulations of binary polymer mixtures in droplets, considering both monodisperse and polydisperse molecular weight distributions for the longer polymer species. We find that confinement induces a spatial separation of the polymers by length, with the shorter ones moving to the droplet surface. This partitioning causes a distinct increase of the local polymer concentration in the droplet center, which is more pronounced in polydisperse systems. Consequently, the systems exhibit liquid-liquid phase separation at average polymer concentrations where bulk systems are still in the one-phase regime.
