Issue 45, 2020

Stratification of polymer–colloid mixtures via fast nonequilibrium evaporation

Abstract

In drying liquid films of polymer–colloid mixtures, stratification in which polymers are placed on top of larger colloids is studied. It is often presumed that the formation of segregated polymer–colloid layers is solely due to the proportion in size at fast evaporation as in binary colloid mixtures. By comparing experiments with a theoretical model, we found that the transition in viscosity near the drying interface was another important parameter for controlling the formation of stratified layers in polymer–colloid mixtures. At high evaporation rates, increased polymer concentrations near the surface lead to a phase transition from a semidilute to concentrated regime, in which colloidal particles are kinetically arrested. Stratification only occurs if the formation of a stratified layer precedes the evolution to the concentrated regime near the drying interfaces. Otherwise, the colloids will be trapped by the polymers in the concentrated regime before forming a segregated layer. Also, no stratification is observed if the initial polymer concentration is too low to form a sufficiently high polymer concentration gradient within a short period of time. Our findings are relevant for developing solution-cast polymer composites for painting, antifouling and antireflective coatings.

Graphical abstract: Stratification of polymer–colloid mixtures via fast nonequilibrium evaporation

Supplementary files

Article information

Article type
Paper
Submitted
19 Ago 2020
Accepted
24 Sep 2020
First published
25 Sep 2020

Soft Matter, 2020,16, 10326-10333

Stratification of polymer–colloid mixtures via fast nonequilibrium evaporation

K. Lee and S. Q. Choi, Soft Matter, 2020, 16, 10326 DOI: 10.1039/D0SM01504K

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements