Modeling of Side-Chain Liquid Crystal Polysiloxanes

Molecular dynamics (MD) simulations of polysiloxanes havm& cholesterol and methoxynitrostilbene (MONS) substituents tethered 10 the siloxane backbone by an allyloxybenzoate spacer group demonstrated that ordering involving all of the substituents developed quite rapidly, even though only the cholesterol group by itself inherently mesogemc The observed ordering varied with the nature and arrangement of the substituents Generally, strong interactions between cholesterol groups iesulted in the longest lived pair-wise associations. MONS substituents also showed orientation, aosing primarily from their associations with cholesterol mesogens The overall order parameter was typically unaffected by the incorpoiation of MONS at tractions of the order of 25% The polymer having alternating MONS and cholesterol substituents did not develop any significant order Association lifetimes were not simply related to order parameter Polymers which achievea the highest ordei parameters did not exhibit the longest association lifetimes Cholesterol - cholesteiol associations tended to be the longest, MONS - MONS association the shortest.