%0 Journal Article
%A Fortini, Andrea
%A Sear, Richard P.
%D 2017
%T Stratification and Size Segregation of Ternary and
Polydisperse Colloidal Suspensions
during Drying
%U https://acs.figshare.com/articles/journal_contribution/Stratification_and_Size_Segregation_of_Ternary_and_Polydisperse_Colloidal_Suspensions_during_Drying/4960481
%R 10.1021/acs.langmuir.7b00946.s002
%2 https://ndownloader.figshare.com/files/8342774
%K power-law dependence
%K Size Segregation
%K film properties
%K Brownian dynamics simulations
%K ternary mixture
%K polydisperse spheres
%K particle size distribution
%K stratification morphologies
%K Polydisperse Colloidal Suspensions
%K bottom part
%K polydisperse mixtures
%K particle size
%K phoretic velocity
%K segregation effect
%K simulation show
%X We
investigate the drying process of three-component and polydisperse
colloidal suspensions using Brownian dynamics simulations. We have
previously reported (Phys. Rev. Lett. 2016, 116, 118301) on the drying of binary mixtures.
For binary mixtures, we found that a gradient of colloidal osmotic
pressure develops during drying and that this leads to the final film
being stratified with a layer of smaller particles on top of a layer
of larger particles. Here, we find that stratification by size is
very general and also occurs in ternary and polydisperse mixtures.
We name the segregation effect colloidal diffusiophoresis. In particular,
we show that by changing the composition of a ternary mixture, different
stratification morphologies can be achieved and hence the film properties
can be tuned. In polydisperse spheres, colloidal diffusiophoresis
leads to enrichment in the large particles at the bottom part of the
film, whereas the top part is enriched with smaller particles. This
segregation means that in the final film, the particle size distribution
depends on height. Thus, the properties of the film will then depend
on height. We propose a model that predicts a power-law dependence
of the phoretic velocity on particle size. Results from the model
and simulation show a good agreement.
%I ACS Publications