摘要
为了制备一种既具有柔性,又具有光学各向异性的自支撑聚合物液晶复合薄膜,文中采用溶胶-凝胶法,以纳米SiO2、聚乙烯醇(PVA)和液晶(LC)为原料制备得到柔性的SiO2/PVA/LC聚合物分散液晶(PDLC)薄膜,研究了十六烷基三甲基溴化铵(HTAB)和乙基三甲氧基硅烷(ECETMS)作为改性剂对PDLC薄膜各组分相容性的影响。通过傅里叶变换红外光谱仪(FTIR)、热台偏光显微镜(POM)、扫描电子显微镜(SEM)和差示扫描量热仪(DSC),对不同条件下制备所得的PDLC薄膜的表面形貌和热力学行为进行了表征;利用可见分光光度计研究了不同PDLC薄膜的电光性能。研究结果表明:向复合体系引入乙基三甲氧基硅烷可以大大提高SiO2/PVA/LC薄膜中各组分的相容性,同时也提高了复合材料的熔点,相对于纯的PVA薄膜,复合薄膜的熔点从90.3℃升至135.2℃。通过PDLC的电光性能分析发现,加入乙基三甲氧基硅烷改性后的复合薄膜的电光性能明显得到了提高,当电压为16 V时,其最高透过率可达86.77%。
The polymer dispersed liquid crystal(PDLC) films combined the flexibility,self-standing and optical anisotropic properties of polymer and liquid crystals.The SiO2/PVA/LC composite films were prepared with nanosilica,polyvinyl alcohol(PVA) and liquid crystal(LC) by sol-gel method.The compatibility and flexibility of PDLC films were modified by the compounds of hexadecyl trimethyl ammonium bromide(HTAB) and ethyl trimethoxysilane(ECETMS),respectively.The PDLC films structures and thermodynamic behavior of PDLC fimls were characterized by fourier transform infrared spectrometer(FTIR),polarized light microscope(POM),scanning electron microscope(SEM) and differential scanning calorimeter(DSC).The electro-optic properties of the films were tested by a UV-vis spectrophotometer.The results showed that the flexibility of Nano-SiO2/PVA/LC film was improved greatly by adding the compound of ethyltrimethoxysilane.The DSC analysis and electro-optical properties indicated that the samples modified by ECETMS also had the good thermodynamic and electric-optical properties.The melting point of the ECETMS modified film increased from 90.3 ℃ to 135.2 ℃ relative to the pure PVA film.And when the voltage is 16 V,the transmittance of the film could reach 86.77%.
作者
刘家敏
牛小玲
朱生勃
王磊
LIU Jiamin;NIU Xiaoling;ZHU Shengbo;WANG Lei(School of Materials and Chemical Engineering,Xi’an Technological University,Xi’an 710021,China)
出处
《西安工业大学学报》
CAS
2019年第5期565-572,共8页
Journal of Xi’an Technological University
基金
国家自然科学基金（61704133）
陕西省教育厅重点实验室项目（18JS051）
关键词
聚合物分散液晶
溶胶-凝胶法
纳米SIO2
电光性能
polymer dispersed liquid crystals
sol-gel method
nano-silica
electro-optic properties
