Three stage-volume phase transitions of a side-chain liquid crystalline elastomer immersed in nematic solvents

摘要

We theoretically study volume phase transitions of a side-chain liquid crystalline elastomer (LCE) immersed in nematic solvents. Six different uniaxial nematic phases (N1∥, N1⊥, N2∥, N2⊥, N3∥, and N3⊥) are defined by using orientational order parameter Sm of a side-chain mesogen, Sb of a backbone chain, and S0 of a nematic solvent inside the gel. We derive the free energy of a side-chain LCE dissolved in nematic solvents and calculate the swelling behavior of the LCE, the order parameters, and the deformations of the LCE as a function of temperature. We find various phase transitions of the LCE, such as the isotropic (I)-N1∥-N3⊥ and the I-N2∥-N3∥, etc., accompanied by volume phase transitions. These results present new concepts in the structure of a side-chain LCE dispersed in nematic solvent molecules. © 2010 American Institute of Physics Article Outline INTRODUCTION FREE ENERGY EQUILIBRIUM SWELLING OF A SIDE-CHAIN NEMATIC GEL RESULTS Side-chain LCE with a flexible backbone chain Side-chain LCE with LC backbone chains SUMMARY