Jump to main content
Jump to site search


Simultaneous uniaxial extensional deformation and cylindrical confinement of block copolymers using non-equilibrium molecular dynamics

Author affiliations

Abstract

Using coarse-grained nonequilibrium molecular dynamics, symmetric block copolymers are simulated under the combined effects of cylindrical confinement and uniaxial extensional deformation. For a given confinement diameter, a block copolymer (BCP) will self-assemble into a fixed number of concentric cylinder lamellae at equilibrium. The changing diameter during uniaxial extensional deformation therefore is expected to affect the morphology of the BCPs. The aim of this study is to investigate the interplay of deformation and confinement on BCP morphology by varying the simulation strain rate and diameter. Two different simulation approaches are conducted: constant time simulations with varying initial diameter and constant strain simulations with varying simulation time. A comparison of self-assembly at different strain rates shows that for low strain rates, near-equilibrium morphology can form despite the deformation, while for progressively higher strain rates, extra lamellae and disordered morphologies appear. By defining a Weissenberg number based on the deformation and polymer self-assembly time-scales, the morphologies at different strain rates and diameters are explained. Using the time scale analysis, ordered morphologies appear for Wi < 1, while extra lamellae and disordered morphologies occur at Wi > 1. For the latter case, the cylinder diameter shrinks too quickly for polymers to form the equilibrium morphology, which results in a mixture of lamellar structures along the cylinder length.

Graphical abstract: Simultaneous uniaxial extensional deformation and cylindrical confinement of block copolymers using non-equilibrium molecular dynamics

Back to tab navigation

Supplementary files

Publication details

The article was received on 19 Sep 2017, accepted on 18 Jan 2018 and first published on 18 Jan 2018


Article type: Paper
DOI: 10.1039/C7SM01889D
Citation: Soft Matter, 2018, Advance Article
  •   Request permissions

    Simultaneous uniaxial extensional deformation and cylindrical confinement of block copolymers using non-equilibrium molecular dynamics

    G. L. Shebert and Y. L. Joo, Soft Matter, 2018, Advance Article , DOI: 10.1039/C7SM01889D

Search articles by author

Spotlight

Advertisements