Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo, 113-8656, Japan.
Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, Tokyo, 113-8656, Japan.
Sci Rep. 2023 May 31;13(1):8791. doi: 10.1038/s41598-023-35575-w.
Liquid-liquid phase separation (LLPS), an important phenomenon in the field of polymer science and material design, plays an essential role in cells and living bodies. Poly(vinyl alcohol) (PVA) is a popular semicrystalline polymer utilized in the synthesis of artificial biomaterials. The aqueous solutions of its derivatives with tuned degrees of saponification (DS) exhibit LLPS. However, the miscibility and LLPS behavior of PVA aqueous solution are still unclear. This study describes the miscibility diagram of the ternary mixture, where water and two types of poly(vinyl alcohol) (PVA) with different DSs [98 (PVA98), 88 (PVA88), 82 (PVA82), and 74 mol% (PVA74)] were blended. UV-Vis measurement was conducted to evaluate the miscibility. Immiscibility was more pronounced at elevated temperatures, exhibiting LLPS. The ternary immiscibility diagram, displaying miscible-immiscible behaviors in the aqueous mixtures of PVA74:PVA98, PVA82:PVA98, and PVA88:PVA98 (blended at a constant volume ratio), indicated that increasing the concentration, temperature, and blend ratio of PVAs at a lower DS increased immiscibility, suggesting that the free energy of mixing increases with increasing these parameters. The miscible-immiscible behaviors of PVAs/water systems provide fundamental knowledge about LLPS and the design of PVA-based materials.
液-液相分离（LLPS）是聚合物科学和材料设计领域的一个重要现象，在细胞和生物体中起着至关重要的作用。聚乙烯醇（PVA）是一种常用的半结晶聚合物，用于合成人工生物材料。其具有不同皂化度（DS）的衍生物的水溶液表现出 LLPS。然而，PVA 水溶液的混溶性和 LLPS 行为仍不清楚。本研究描述了三元混合物的混溶性图，其中水和两种不同 DS 的聚（乙烯醇）（PVA）[98（PVA98）、88（PVA88）、82（PVA82）和 74 mol%（PVA74）]混合在一起。通过 UV-Vis 测量来评估混溶性。在较高温度下，不混溶性更为明显，表现出 LLPS。三元不混溶性图显示了 PVA74:PVA98、PVA82:PVA98 和 PVA88:PVA98（以恒定体积比混合）水溶液的混溶性-不混溶性行为，表明随着较低 DS 的 PVA 的浓度、温度和混合比的增加，不混溶性增加，表明混合自由能随这些参数的增加而增加。PVA/水体系的混溶性-不混溶性行为为 LLPS 和基于 PVA 的材料的设计提供了基础的知识。
