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Water Flux Induced Reorientation of Liquid Crystals
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posted on 2017-12-15, 21:05 authored by Hadi Ramezani-Dakhel, Monirosadat Sadati, Rui Zhang, Mohammad Rahimi, Khia Kurtenbach, Benoît Roux, Juan J. de PabloIt is well understood
that the adsorption of solutes at the interface
between a bulk liquid crystal phase and an aqueous phase can lead
to orientational or anchoring transitions. A different principle is
introduced here, whereby a transient reorientation of a thermotropic
liquid crystal is triggered by a spontaneous flux of water across
the interface. A critical water flux can be generated by the addition
of an electrolyte to the bulk aqueous phase, leading to a change in
the solvent activity; water is then transported through the liquid
crystal phase and across the interface. The magnitude of the spontaneous
water flux can be controlled by the concentration and type of solutes,
as well as the rate of salt addition. These results present new, previously
unappreciated fundamental principles that could potentially be used
for the design of materials involving transient gating mechanisms,
including biological sensors, drug delivery systems, separation media,
and molecular machines.