Abstract
Photo-initiated thiol-ene click chemistry is used to develop shape memory liquid crystalline networks (LCNs). A biphenyl-based di-vinyl monomer is synthesized and cured with a di-thiol chain extender and a tetra-thiol crosslinker using UV light. The effects of photo-initiator concentration and UV light intensity on the curing behavior and liquid crystalline (LC) properties of the LCNs are investigated. The chemical composition is found to significantly influence the microstructure and the related thermomechanical properties of the LCNs. The structure-property relationship is further explored using molecular dynamics simulations, revealing that the introduction of the chain extender promotes the formation of an ordered smectic LC phase instead of agglomerated structures. The concentration of the chain extender affects the liquid crystallinity of the LCNs, resulting in distinct thermomechanical and shape memory properties. This class of LCNs exhibits fast curing rates, high conversion levels, and tailorable liquid crystallinity, making it a promising material system for advanced manufacturing, where complex and highly ordered structures can be produced with fast reaction kinetics and low energy consumption.
| Original language | English |
|---|---|
| Pages (from-to) | 1760-1770 |
| Number of pages | 11 |
| Journal | Soft Matter |
| Volume | 16 |
| Issue number | 7 |
| DOIs | |
| State | Published - Feb 21 2020 |
Funding
This work was supported by the Air Force Office of Scientific Research (Award FA-9550-12-1-0108). The MD simulations were performed at the National Center for Computational Sciences (NCCS) and used resources of the Oak Ridge Leadership Computing Facility (OLCF) at the ORNL, which is supported by the Office of Science of the U.S. DOE under contract number DE-AC05-00OR22725. WAXS and computer simulation studies were conducted at the Center for Nanophase Materials Sciences (CNMS), which is sponsored by the ORNL Scientific User Facilities Division, DOE Office of Basic Research Sciences. In addition, some of the research was sponsored by the Critical Materials Institute, Building Technologies Office, Office of Energy Efficiency and Renewable Energy, and Advanced Manufacturing Office, under contract DE-AC05-00OR22725 with UT-Battelle, LLC. We also thank the China Scholarship Council (No. 201506600009) for their financial support.
| Funders | Funder number |
|---|---|
| Critical Materials Institute, Building Technologies Office | |
| DOE Office of Basic Research Sciences | |
| National Center for Computational Sciences | |
| U.S. Department of Energy | DE-AC05-00OR22725 |
| Air Force Office of Scientific Research | FA-9550-12-1-0108 |
| Office of Science | |
| Office of Energy Efficiency and Renewable Energy | |
| Oak Ridge National Laboratory | |
| China Scholarship Council | 201506600009 |
