论文标题
通过在不混溶的液体界面上h键获得的聚合物膜的生长机理
Growth mechanism of polymer membranes obtained by H-bonding across immiscible liquid interfaces
论文作者
论文摘要
聚合物在液体界面上的络合是一种新兴技术，可生产全液体可打印和自我修复装置和膜。控制组装过程至关重要，但是发挥作用的机制尚不清楚。使用两种不同的反射测量方法，我们研究了在平坦的液态液界面上H键的PPO-PMAA膜的自发生长。我们发现，膜厚度H随时间t的生长为H〜T^（1/2），它让人联想到扩散限制的过程。但是，违反直觉，我们观察到，随着PPO摩尔质量的增加，此过程速度更快。我们能够通过一个模型来合理化这些结果，该模型认为PPO链在生长的膜中的扩散。后者的体系结构被描述为类似凝胶的多孔网络，其孔径比扩散的PPO链的半径小得多，从而诱导了阻碍扩散过程的熵屏障。从实验数据和模型结果之间的比较，我们提取了有关膜的显微镜结构的一些关键信息。这项研究为具有最佳特性的自组装膜和胶囊的合理设计开辟了途径。
Complexation of polymers at liquid interfaces is an emerging technique to produce all-liquid printable and self-healing devices and membranes. It is crucial to control the assembly process but the mechanisms at play remain unclear. Using two different reflectometric methods, we investigate the spontaneous growth of H-bonded PPO-PMAA membranes at a flat liquid-liquid interface. We find that the membrane thickness h grows with time t as h~t^(1/2), which is reminiscent of a diffusion-limited process. However, counter-intuitively, we observe that this process is faster as the PPO molar mass increases. We are able to rationalize these results with a model which considers the diffusion of the PPO chains within the growing membrane. The architecture of the latter is described as a gel-like porous network, with a pore size much smaller than the radius of the diffusing PPO chains, thus inducing entropic barriers that hinder the diffusion process. From the comparison between the experimental data and the result of the model, we extract some key piece of information about the microscopic structure of the membrane. This study opens the route toward the rational design of self-assembled membranes and capsules with optimal properties.
