Jan Forsman
Professor
Non-monotonic phase behaviour of a mixture containing non-adsorbing particles and polymerising rod-like molecules
Author
Summary, in English
Hypothesis: Previous works have shown that many-body interactions induced by dispersants with increasing correlation length will generate a diminishing two-phase region [Soft Matter 14, 6921 (2018)]. We conjecture that the attenuation of the depletion attraction due to many-body interactions is a ubiquitous phenomenon in medium-induced interactions. We propose mixtures of colloidal particles and rod-like polymers as a feasible experimental system for verifying these predictions, since the intra-molecular correlations are not screened in a good solvent for rod-like polymers as they are in flexible polymers. The length of the rods can grow and become the dominant length scale that determines the range of the depletion interactions for the imbedded non-adsorbing particles. Simulations: We study many-body depletion forces induced by polymerizing rod-like polymers on spherical non-adsorbing colloids, using Metropolis Monte Carlo simulations. We also employ a simple mean-field theory to further justify our numerical predictions. Findings: We demonstrate that the phase diagram displays the same qualitative features that have previously been predicted by many-body theory, for mixtures containing flexible polymers under theta solvent conditions. The contraction of the particle two-phase region that we observe, as the correlation length increases beyond some specific value, could be a signature of the weakening of the depletion caused by many-body effects.
Department/s
- Computational Chemistry
Publishing year
2020-05-15
Language
English
Pages
25-35
Publication/Series
Journal of Colloid and Interface Science
Volume
568
Full text
Document type
Journal article
Publisher
Academic Press
Topic
- Physical Chemistry (including Surface- and Colloid Chemistry)
Keywords
- Depletion interaction
- Many-body effects
- Particle-rod mixture
Status
Published
ISBN/ISSN/Other
- ISSN: 0021-9797