Simulations of Side Chain Liquid Crystalline Polysiloxanes
Abstract
Molecular dynamcics simulations have been used to investigate the behavior of polysiloxanes having biphenyl, cholesteryl, and methoxynitrostilbene (MONS) substituents tethered to the polymer backbone by allyloxy- and allyloxybenzoate spacer groups. The assemblies which develop have order parameters comparable to experimental values measured for the related cyclic siloxanes. Associations between cholesteryl substituents dominate the behavior, but biphenyl-cholesterol and MONS-cholesterol associations also play important roles. The flexibility of the siloxane backbone, combined with that of the spacer, is sufficient to allow comparable ordering in most of the substituent arrangements (alternating, block, etc.) investigated. The role of the tethering has been examined by comparing the behavior of polymer with that displayed by detached substituents, with and without the spacer groups. The spacers play a significant role in the ordering which develops among the mesogens. Longer duration simulations, utilizing multiple timesteps and representing various groups of atoms as single bodies, provide results comparable to the fully atomistic simulations while requiring about 1/20 the computation time.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 1998
- Bibcode:
- 1998APS..MARO38134A