Solvent vapor exposure could transform a crystalline or smectic liquid crystal (LC) film into nematic and isotropic phases under ambient conditions. The average time for such phase transitions is found to linearly reduce with an increase in vapor pressure and reduction in the molecular weight of solvents. Such responses of solvent vapor-annealed phase transitions of a nanoparticle-loaded LC droplet were then converted into an electrical signal, wherein the electrical resistance reduced (increased) with time upon destruction (restoration) of the orientational order of the LC matrix. Variation in the electrical response was used to identify the volatile organic vapors, phase transition of LCs, rate of diffusion–absorption of solvent into LCs, and rate of desorption–evaporation of solvent from LCs. Pattern-directed phase transitions on physically heterogeneous surfaces showed a faster (slower) kinetics on thinner (thicker) patterns. However, for chemically heterogeneous surfaces, weaker (stronger) anchoring of LCs on hydrophobic (hydrophilic) patches ensured a faster (slower) transition.

中文翻译：

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液晶膜的图案定向相变和VOC感测

在环境条件下，暴露于溶剂蒸汽会使晶体或近晶液晶（LC）膜转变为向列相和各向同性相。发现这种相变的平均时间随着蒸气压的增加和溶剂分子量的减少而线性减少。然后将负载纳米颗粒的LC液滴的溶剂蒸汽退火的相变的这种响应转换成电信号，其中，随着LC基质的取向顺序的破坏（恢复），电阻随时间减小（增加）。电响应的变化可用于确定挥发性有机蒸气，液相色谱的相变，溶剂向液相色谱的扩散-吸收速率以及溶剂从液相色谱的解吸-蒸发速率。物理异质表面上由图案定向的相变在较薄（较厚）的图案上显示出更快（较慢）的动力学。但是，对于化学异质表面，LC在疏水性（亲水性）斑块上的弱锚固（更牢固）可确保更快（较慢）的过渡。