摘要
Abstract
To address the mismatch between the high-temperature curing required by conventional vertical alignment layers and the limited thermal tolerance of flexible transparent conductive substrates in flexible reverse-mode liquid-crystal(LC)dimming films,a low-temperature vertical alignment process and substrate compatibility screening were investigated.On glass substrates,a low-temperature vertical alignment agent was cured at 120～140℃with a 5℃step to evaluate the effects of curing temperature on LC pretilt angle and its uniformity,together with the variations in transmittance and haze before/after curing.A rubbing treatment was further introduced at the optimal curing temperature to improve alignment quality.The electro-optical response of the aligned LC cell was verified by voltage-transmittance(V-T)characterization,and stability was assessed via room-temperature storage and voltage cycling.Finally,under the same processing conditions,five commercial flexible transparent conductive substrates were compared in terms of sheet-resistance thermal stability and the changes in transmittance/haze after alignment-layer curing,aiming to identify compatible substrates.As the curing temperature increased from 120℃to 140℃,the mean pretilt angle decreased from 0.69° to 0.38° and the standard deviation decreased from 0.30° to 0.04°.With rubbing at 140℃,the pretilt angle was further reduced to 0.19°,accompanied by a decrease in haze.The LC cell exhibited a clear threshold behavior in the V-T curve(Vth≈8.69 V;Von≈ 14.06 V).After 30-day storage at room temperature,the pretilt change was～0.02°,and electro-optical parameters remained stable after voltage cycling.Among the tested substrates,the f3-type PET/ITO showed the most stable sheet resistance after thermal treatment at 140℃and maintained a high transmittance(～90%)with limited haze variation after curing,outperforming the other candidates.A low-temperature vertical alignment processing window suitable for flexible LC dimming films was established,and a compatible flexible transparent conductive substrate was identified under unified conditions,providing practical guidance for process transfer and substrate selection of flexible reverse-mode LC dimming films.关键词
反式液晶调光器件/柔性透明导电膜/低温垂直取向/预倾角Key words
reverse-mode liquid crystal dimming device/flexible transparent conductive films/low-temperature vertical alignment/pretilt angle分类
信息技术与安全科学
