Modeling Solution Drying by Moving a Liquid-Vapor Interface: Method and Applications

Abstract

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.

14 pages, 7 figures

References in corpus (14)

• Interaction potentials for soft and hard ellipsoids
• Dynamic stratification in drying films of colloidal mixtures
• Dispersing Nanoparticles in a Polymer Film via Solvent Evaporation
• Cross-interaction drives stratification in drying film of binary colloidal mixtures
• Structure Formation in Soft Matter Solutions Induced by Solvent Evaporation
• Structure and Diffusion of Nanoparticle Monolayers Floating at Liquid/Vapor Interfaces: A Molecular Dynamics Study
• Molecular Dynamics Simulations of Evaporation-Induced Nanoparticle Assembly
• Stratification in Drying Films Containing Bidisperse Mixtures of Nanoparticles
• Influence of hydrodynamic interactions on stratification in drying mixtures
• Stratification of drying particle suspensions: Comparison of implicit and explicit solvent simulations
• Capillary Forces on a Small Particle at a Liquid-Vapor Interface: Theory and Simulation
• Chain Conformations and Phase Separation in Polymer Solutions with Varying Solvent Quality
• Stratification of polymer mixtures in drying droplets: hydrodynamics and diffusion
• Ordering Nanoparticles with Polymer Brushes