Preparation of temperature-response fibers with cholesteric liquid crystal dispersion

Abstract

Cholesteric liquid crystal (CLC) dispersion was prepared using the mixed emulsifiers composed of Tween 20 and Span 80. The effects of preparation parameters on mean particle size and particle size distribution of CLC dispersion were investigated, demonstrating that the CLC mixture was better dispersed and stabilized above the phase transition temperature, and keeping the HLB at 11.7, emulsifier amount at 1.0%, dispersing speed at 5000 rpm for 60 min, the CLC particle in the dispersion were spherical and had a reversible thermochromic property. This dispersion was then used in the preparation of temperature-response PVP/CLC fibers in a water-based system by electrospinning. Polarized optical microscopy and scanning electron microscopy image reveal that CLC particles were incorporated into the PVP/CLC fibers, protecting the CLC from leaking out. The PVP/CLC fibers exhibited an optical temperature response in the temperature range from 25 to 60 °C.