1135
Structure of Polymerized Ionic Liquids from Neutron Scattering Perspective

Monday, 29 May 2017: 09:00
Prince of Wales (Hilton New Orleans Riverside)
H. Liu (University of Tennessee, Knoxville) and S. Paddison (University of Tennessee)
Recent enthusiasm in polymerized ionic liquids (polyILs) with enhanced mechanical characteristics of polymers and unique physicochemical properties inherent in ionic liquids is fueled by their ability to selectively transport ions. Experiments suggest the morphology of polyILs has a significant effect on ion transport. Despite significant interest in the morphology of polyILs, investigation by traditional experimental techniques remains elusive. Few X-ray scattering experiments yield structural information, and provide little atomistic details. Neutron scattering has not been done on this important class of materials. In our recent ACS Macro Letters work, we reported a comparison of results from atomistic simulations with X-ray scattering experiments on 3 homologous polyILs that strongly support the capability of simulations to provide fundamental understanding of the structure and morphology. Herein, we extend the analysis of morphology to a complete homologous series of poly(CnVim Tf2N) (2 <= n <= 8) with emphasis on selective neutron scattering. We have demonstrated that neutron scattering with isotopic labeling along with X-ray scattering provides versatile ways to vet the intrinsic structure. The neutron scattering profiles markedly depend on the isotopic substitution pattern and that isotopically labeled neutron and X-ray scattering data do not necessarily lead to the same characteristic correlation length. Such an unintended consequence has a nontrivial implication on exploitation of scattering experiments. Moreover, the experimentally accessible difference scattering spectra based on common factor analysis offer a complementary view to the detailed decomposition of the total structure factor provided in molecular simulation and ESPR modeling. We hope the current work might stimulate experimentalists to explore polyILs using selective neutron scattering.