Self-assembly of Poly(<i>p</i>-phenylene terephthalamide) Nanofibrils: Emergence of Structural Defects

ORAL

Abstract

We provide molecular level insights on the self-assembly mechanisms of poly(p-phenylene terephthalamide) (poly(PPTA)) chains in a strong solvent by using large scale molecular dynamics simulations based on a rigorous development of a coarse-grained potential model. Ordered liquid crystalline phases of poly(PPTA)n chains facilitated by the solvent are reported for various polymer lengths, n and initial configurations. We find that the degree of hydrogen bond (H-bond) plane ordering depends sensitively on the polymer length and initial polymer alignments. Our largescale simulations suggest an increased propensity of grain boundary formation parallel to the H-bond direction with guided initial configuration. Our results reveal that the trapping of solvent nanoclusters within the ordered domains of poly(PPTA) fibrils give rise to structural defects.

*This work was supported by the US Army Research Laboratory under contract number W911NF-16-2-0189. Computations were performed on the Blue Waters supercomputer at the National Center for Supercomputing Applications (NCSA).

Presenters

  • Santhosh Mogurampally

    • Institute for Computational Molecular Science, Temple University
    • Chemical Engineering, Univ of Texas, Austin
    • Univ of Texas, Austin

Authors

  • Santhosh Mogurampally

    • Institute for Computational Molecular Science, Temple University
    • Chemical Engineering, Univ of Texas, Austin
    • Univ of Texas, Austin
  • Giacomo Fiorin

    • Institute for Computational Molecular Science, Temple University
  • Michael Klein

    • Institute for Computational Molecular Science, Temple University
    • Department of Physics, Temple University
    • Temple University
    • Chemistry, Temple University