Constructing liquid crystalline elastomer multi-fold gratings with side-on epoxy liquid crystalline monomers

Abstract

ABSTRACT The fabrication of liquid crystalline elastomer (LCE) with reversible deformation is promising for development of intelligent materials and equipment. Preparing new liquid crystalline monomer (LCM) and developing novel LCE structures are crucial for the fabrication of advanced LCE. Herein, we design and synthesis a series of side-on nematic epoxy LCM, and then fabricate corresponding LCE with micropillar array via photoinitiated polymerisation of a magnetic induced oriented LCMs with soft lithography patterned structures. 1H NMR, 13C NMR, COSY, FTIR and MS spectra confirm the structures of the LCMs. DSC and POM results demonstrate that the LCMs are nematic liquid crystals. SEM, OM, and POM observations indicate the successful fabrication of LCE micropillars that exhibit reversible contraction and extension during heating and cooling cycles. In addition, the thermal induced reversible deformation of the LCE micropillars is closely related to the structure of the LCM. By using the same method, functional LCE with multi-fold gratings are prepared by using the multi-fold gratings master mask during the fabrication process, providing a material foundation for the construction of intelligent surfaces that can selectively diffract light under external thermal stimuli.