基于液晶取向变化检测有机胺化合物的方法

采用旋涂法在玻璃基底表面制备4-三乙氧基硅基丁腈有机膜.有机膜表面采用丝绒布进行摩擦和5％乙酸水溶液改性处理后成为特异敏感膜.将此敏感膜的载玻片面对面贴合后,在其间组装液晶E7分子膜,表征液晶分子排列状态；采用挥发法在敏感膜表面组装液晶膜,制备成了检测目标物的复合材料.采用此种材料对甲胺、乙胺和二乙胺等有机胺化合物及实验室常见干扰气体进行检测,发现只有有机胺化合物会对材料的液晶分子排列状态产生影响,导致液晶膜的亮度发生改变,从而实现对目标物的特异检测.对有机胺化合物检测过程中,其响应速率为V甲胺＜V乙胺＜V二乙胺,恢复速率为:V乙胺＜V乙胺＜V甲胺；刘乙胺的检出限为0.46 mg/m3.本方法具有较高的检测灵敏度,抗干扰能力较强且操作简单,可发展为现场检测有机胺化合物的新技术.

Optical Detection of Organoamine Based on Orientation Transition of Liquid Crystal

The sensitive films on ordinary glass slides were prepared by assembling 4-(triethoxysilyl)-butanenitril organic film using spinning coated method,mechanically rubbed and then functionalized with 5% acetic acid.Two glass slides with the sensitive films were stick face to face and liquid crystal(LC) E7 film was inserted in-between,the array state of LC was then investigated using polarized microscope.Moreover,LC film was also prepared using evaporating solvent method,which formed the LC composite material for organoamine detection.When the composite material was exposed to organoamine vapors,E7 molecules underwent a transition from a planar or tilted orientation to another orientation;meanwhile,the image change and detected target molecules were observed.In addition,we further demonstrated that some common interference gas in lab yielded negative results in terms of the above images change.In the process of organoamine detection,the response rate is vmethylamine