摘要

Polymer-dispersed liquid crystal (PDLC) film, which is formed by dispersing liquid crystal (LC) droplets into a polymer network structure, is a kind of material that can realize the conversion between the opaque and the transparent state by exerting a voltage. It can be widely used in fields such as smart switchable glass. In this work, the crosslinking reaction products of bisphenol A epoxy resin (EP) and two polyether dia-mines with different molecular weights (D400 and D2000) were used as the PDLC matrix. Based on the quenching process, the effects of LC concentration, curing temperature and time, and n(EP):n(D400):n(D2000) on the transmittance (Toff and Ton) and haze under off-state and on-state as well as threshold and saturation voltages (Vth and Vsat) of PDLC samples were investigated. At the same time, the size and distribution density of the LC droplets were observed by polarizing microscope. The results show that the PDLC film with best overall performance is obtained at the LC concentration of 38 wt%, the curing temperature of 100 ℃, the curing time of 2 h and the n(EP):n(D400):n(D2000) of 4.4:1.75:1; namely, PDLC film shows Toff of 7.05%, Ton of 66.6%, off-state haze of 90%, on-state (60 V) haze of 15.6%, Vth of 17 V and Vsat of 33 V. In addition, the effects of size and distribution of LC droplet as well as compactness of resin network structure on the optical switching performance of PDLC film were also analyzed. ? 2022, Materials Review Magazine. All right reserved.

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