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Published on: October 31, 2019
Isotropic and nematic liquid crystalline phases of adaptive rotaxanes
Hao He1, Edith M Sevick1, David R M Williams2
1Research School of Chemistry, The Australian National University, Canberra ACT 0200, Australia.
Abstract:
We describe the thermodynamics of a solution of rotaxanes which can change their length from a short state of length L to a long state of length qL in response to their surrounding environment. We call these rotaxanes "adaptive." We show that such a system can exhibit both isotropic and nematic liquid crystalline phases. The system shows several interesting kinds of behaviour. First we predict that the fraction of short-length rotaxanes increases linearly with concentration and is a maximum at the critical concentration that marks the isotropic to nematic transition. Second, the critical concentration shows a minimum at a certain value of q. Our model suggests that the effect of adaptive length changes is most dramatic at small q and where the long state is slightly favoured.
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