论文标题
通过移动液态蒸气接口来建模溶液干燥:方法和应用
Modeling Solution Drying by Moving a Liquid-Vapor Interface: Method and Applications
论文作者
论文摘要
通过将液体蒸气界面移动到各种溶液膜和液滴中,一种使用隐式溶剂模型模拟软物质溶液的干燥过程的方法。对于聚合物和纳米颗粒的溶液,我们观察到“顶端”分层,类似于先前使用显式溶剂模型发现的分层。此外,即使纳米颗粒的大小小于聚合物链回旋的半径,也会发现“ TOP聚合物”。对于纳米颗粒的二分散混合物的悬浮液滴,我们表明可以以快速蒸发速率通过“小型外部”分层机制获得纳米颗粒的核心壳簇。当蒸发速率降低时,还观察到“大开眼室”分层和均匀的颗粒分布。具有各种形态学的聚合物颗粒,包括Janus球,核壳颗粒和斑块颗粒,是通过将快速蒸发与聚合物与液体蒸气界面之间的受控相互作用相结合,从聚合物溶液的干燥液滴中产生。我们的结果验证了移动界面方法对多种干燥系统的适用性。指出了该方法的局限性,并在该方法可能失败的情况下向潜在的从业人员提供了警告。
A method of simulating the drying process of a soft matter solution with an implicit solvent model by moving the liquid-vapor interface is applied to various solution films and droplets. For a solution of a polymer and nanoparticles, we observe "polymer-on-top" stratification, similar to that found previously with an explicit solvent model. Furthermore, "polymer-on-top" is found even when the nanoparticle size is smaller than the radius of gyration of the polymer chains. For a suspension droplet of a bidisperse mixture of nanoparticles, we show that core-shell clusters of nanoparticles can be obtained via the "small-on-outside" stratification mechanism at fast evaporation rates. "Large-on-outside" stratification and uniform particle distribution are also observed when the evaporation rate is reduced. Polymeric particles with various morphologies, including Janus spheres, core-shell particles, and patchy particles, are produced from drying droplets of polymer solutions by combining fast evaporation with a controlled interaction between the polymers and the liquid-vapor interface. Our results validate the applicability of the moving interface method to a wide range of drying systems. The limitations of the method are pointed out and cautions are provided to potential practitioners on cases where the method might fail.