Dynamics at the Interface of Structured Block Co-Polymer Thin Films with Polar Solvents: Molecular Dynamics Simulations Insights

ORAL

Abstract

Structured ionic co-polymers consist of multiple blocks whose dynamics facilitate their uses. Here, the dynamics at the interface of an ABCBA pentablock co-polymer with polar solvents is studied by molecular dynamics simulations. The ionic block C is a sulfonated polystyrene (sPS) with sulfonation fraction f=0.55, B is polyethylene-propylene (PEP), and A is poly(t-butyl styrene) (tBS). Simulations are performed using LAMMPS with the polymer and propanol modeled with OPLS-AA force field. The interface evolution with exposure time to propanol is followed and the results are compared with those for the polymer-water interface. The air interface of the neat polymer is dominated by the PEP block. With exposure to propanol, more ionic groups migrate to the interface, similar to the polymer-water interface. However, in contrast to water exposed films, the interface remains dominated by the PEP blocks. Remarkably, the interfacial width of the membrane-propanol system grows with time while the width of the membrane-water interface decreases. Further, water molecules associate predominantly with the ionic blocks and break the ionic clusters while propanol associates with both the ionic and non-ionic polymer segments.

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Presenters

  • Manjula Senanayake

    Department of Chemistry , Clemson University, Clemson, SC, United States,29634, Department of Chemistry, Clemson University, Clemson, SC, United States, Department of Chemistry, Clemson, SC, 29634, United States, Clemson University, Department of Chemistry, Clemson University, Clemson, SC, United States., Chemistry, Clemson University

Authors

  • Manjula Senanayake

    Department of Chemistry , Clemson University, Clemson, SC, United States,29634, Department of Chemistry, Clemson University, Clemson, SC, United States, Department of Chemistry, Clemson, SC, 29634, United States, Clemson University, Department of Chemistry, Clemson University, Clemson, SC, United States., Chemistry, Clemson University

  • Dipak Aryal

    University of Texas at Austin, Department of Chemical Engineering, University of Texas at Austin, Austin, TX, United States, 78712, University of Texas, Austin

  • Gary Grest

    Sandia National Laboratories, Sandia National Laboratories, Albuquerque, NM, United States,87123

  • Dvora Perahia

    Department of Chemistry/Department of Physics, Clemson University, Clemson, SC, United States, 29634, Clemson University, Department of Chemistry/ Department of Physics, Clemson University, Clemson, SC, United States, Department of Chemistry, Clemson, SC, 29634, United States, Clemson University, Department of Physics, Clemson, SC, 29631, United States, Clemson University, Department of Chemistry/Department of Physics, Clemson University, Clemson, SC, United States., Chemistry, Physics, Clemson University