摘要
光聚合诱导相分离法是应用最广泛的制备聚合物分散液晶(PDLC)膜的方法。为了提高PDLC的对比度(CR),通常在PDLC膜中引入二色性染料。然而,目前商业化的染料掺杂PDLC膜还很少,因为光聚合诱导相分离法使用的紫外光会使染料分解;另外,染料会吸收紫外光导致预聚物的聚合速率变慢。亲核试剂引发点击化学反应是最近合成化学的研究热点,可在无紫外光的条件下发生。因此,用亲核试剂引发点击化学反应制备PDLC膜,有望克服传统光聚合诱导相分离法的缺点。本论文,采用亲核试剂引发巯基-烯烃点击化学反应制备PDLC膜,并研究了反应温度对PDLC电光性能的影响。结果表明,温度的改变导致液晶微滴的尺寸发生变化,进而对PDLC的电光性能产生影响。温度升高使得开态透过率(Ton)变小,阈值电压(V_(th))和饱和电压(V_(sat))升高。
Photo-polymerization-induced phase separation is a most widely used method to fabricate polymer dispersed liquid crystal(PDLC)films.Meanwhile,dichroic dye is usually introduced into PDLC films to enhance the contrast ratio.However,until now,commercial dye-doped PDLC films are still very few,because UV-light can make dye decompose in the process of photo-polymerization-in-duced phase separation and dye absorbs UV-light causing the polymerization rate of the prepolymer to slow down.Recently,nucleophile-initiated click reaction,which can be processed without UV-light,is a research hotspot in synthetic chemistry.Thus,fabricating PDLC films via click reaction initiated by nucleophile may hopefully overcome the shortcomings of traditional photo-polymerization-induced phase separation method.In our work,PDLC films were prepared via thiol-ene click reaction initiated by nucleophile.The influences of reaction temperature on electro-optical properties of PDLC were investigated.It was found that reaction temperature influenced the electro-optical properties of PDLC films by changing the droplets size of liquid crystal.With the increase of reaction temperature,ON state transmittance(Ton)decreases,while threshold voltage(V_(th)) and saturation voltage(V_(sat)) increases.
出处
《液晶与显示》
CAS
CSCD
北大核心
2017年第12期968-972,共5页
Chinese Journal of Liquid Crystals and Displays
基金
国家自然科学基金(No.51173115)~~
关键词
聚合物分散液晶
点击化学
反应温度
电光性能
polymer dispersed liquid crystal
click reaction
reaction temperature
electrooptical property