Leslie thermomechanical power in diluted cholesteric liquid crystals
Université de Lyon, Ecole Normale Supérieure de Lyon, Laboratoire de Physique, UMR 5672 of the CNRS 46 Allée d'Italie, 69364 Lyon Cedex 07, France, EU
Received: 7 August 2014
Accepted: 7 October 2014
I measure the Leslie thermomechnical coefficient ν in diluted cholesteric liquid crystals. The chiral molecules are R811 and cholesteryl chloride (CC) and the host nematic liquid crystals are 7CB and MBBA. I show that ν is proportional to the concentration of chiral molecules C when . This allows me to define the Leslie thermomechanical power as by analogy with the helical twisting power, where q denotes the equilibrium twist. I show that the LTP (dynamic in nature) and the HTP (static in nature) are independent in sign and magnitude. In addition, the same chiral molecule can rotate clockwise or counterclockwise depending on the host nematic liquid crystal used.
PACS: 61.30.-v – Liquid crystals / 65.40.De – Thermal expansion; thermomechanical effects / 05.70.Ln – Nonequilibrium and irreversible thermodynamics
© EPLA, 2014