Scaling and Interactions of Linear and Ring Polymer Brushes via DPD Simulations

Author(s)
Martin Jehser, Gerhard Zifferer, Christos Likos
Abstract

Single and double layers of polymer coated surfaces are investigated by means of Dissipative Particle Dynamics (DPD), focusing on the difference between grafted ring and linear chains. Several different surface coverages σ, as well as chain lengths N and brush separations D, are analyzed for athermal, i.e., good solvent, conditions. The size in the form of the radius of gyration R

g, the shape as asphericity δ*, and orientation β*, as well as density profiles as functions of distance from grafting plane r(z), are studied. The effect of an added bond repulsion potential to suppress bond crossing in DPD is analyzed. Scaling laws of R

g and its components R

g⊥ and R

g∥ are investigated. We find R

g ∝ N

v, v = 0.588 for surface coverages below the overlap surface concentration σ

*. For σ > σ* we find R

g⊥ ∝ N

v⊥, v⊥ ≅ 1 and R

g∥ ∝ N

v∥k, v

par; = 1/2 of ring brushes with the standard DPD model and v

∥ ≅ 2/5 with added bond repulsion. The σ dependence of the radius of gyration was found to be R

g ∝ σ

μ with m = 1/3 for surface coverages grater than σ

*. The perpendicular component R

g⊥ scales independent of the bond repulsion potential as R

g⊥ ∝ σ

μ⊥, μ⊥ = 1/3, whereas the scaling of the parallel component exhibits a topological repulsion dependence R

g⊥ ∝ σ

μ∥, μ∥ = -1/12 for standard DPD and μ∥ = -1/6 for bond repulsion.

Organisation(s)
Department of Physical Chemistry, Computational and Soft Matter Physics
Journal
Polymers
Volume
11
No. of pages
17
ISSN
2073-4360
DOI
https://doi.org/10.3390/polym11030541
Publication date
03-2019
Peer reviewed
Yes
Austrian Fields of Science 2012
104017 Physical chemistry, 103023 Polymer physics, 104018 Polymer chemistry
Keywords
ASJC Scopus subject areas
Chemistry(all), Polymers and Plastics
Portal url
https://ucris.univie.ac.at/portal/en/publications/scaling-and-interactions-of-linear-and-ring-polymer-brushes-via-dpd-simulations(4c8dea68-ef39-43d4-8a26-be66353c9123).html