当前位置: X-MOL 学术Soft Matter › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Strain-enhanced sensitivity of polymeric sensors templated from cholesteric liquid crystals.
Soft Matter ( IF 3.4 ) Pub Date : 2020-06-23 , DOI: 10.1039/d0sm00905a
Ozge Batir 1 , Erhan Bat 1 , Emre Bukusoglu 1
Affiliation  

Detection of volatile organic compounds (VOCs) is an important issue due to their harmful impact on human health. In this study, we aimed at enhancing the sensitivity of the anisotropic polymeric films templated from cholesteric liquid crystals (CLCs) in the identification of VOCs at concentrations on the order of 100 ppm. To increase sensitivity, we introduced negative strain to the films in the direction parallel to the helical axis and evaluated its effect on the sensitivity. Specifically, we used LC mixtures of reactive [4-(3-acryloyoxypropyloxy)benzoic acid 2-methyl-1,4-phenylene ester (RM257)], nonreactive E7 mesogen and chiral dopant [4-((1-methylheptyloxycarbonyl)phenyl-4-hexyloxybenzoate) (S-811)] to synthesize CLC-templated polymeric films with programmed strain profiles using a curved wedge cell, and measured their response against a range of toluene vapor concentrations. Based on the obtained results, we demonstrated a relationship between the negative strain in the cholesteric pitch and the sensitivity of the sensor based on spacial responses evaluated from the change in coloring of the film. Our results showed that negative strain helps to increase the sensitivity of the sensors up to 15 times compared to their unstrained counterparts. Moreover, 90% of the equilibrium response is achieved in less than one minute of exposure which offers rapid diagnosis of VOCs. Our tests for the reversibility of the sensors showed that the CLC-templated polymeric films can be used multiple times without a significant loss of sensitivity.

中文翻译:

从胆甾型液晶模板化的聚合物传感器的应变增强灵敏度。

由于挥发性有机化合物(VOC)对人体健康具有有害影响,因此检测是一个重要的问题。在这项研究中,我们旨在提高以胆甾型液晶(CLC)为模板的各向异性聚合物薄膜在鉴定浓度为100 ppm的VOC时的灵敏度。为了提高灵敏度,我们在平行于螺旋轴的方向上向薄膜施加了负应变,并评估了其对灵敏度的影响。具体而言,我们使用了反应性[4-(3-丙烯酰氧基丙氧基)苯甲酸2-甲基-1,4-亚苯基酯(RM257)],非反应性E7液晶元和手性掺杂剂[4-((1-甲基庚基氧羰基)苯基- (S-811)]合成,使用曲面楔形电池合成具有程序化应变曲线的CLC模板聚合物薄膜,并测量了它们对一系列甲苯蒸气浓度的响应。基于获得的结果,我们基于胆甾醇基间距的负应变与传感器灵敏度之间的关系,该传感器基于从薄膜着色变化评估的空间响应而确定。我们的结果表明,与未应变的传感器相比,负应变有助于将传感器的灵敏度提高多达15倍。此外,在不到一分钟的暴露时间内即可达到90%的平衡响应,从而可以快速诊断VOC。我们对传感器的可逆性进行的测试表明,可以多次使用CLC模板的聚合物薄膜,而不会显着降低灵敏度。我们基于胆甾醇间距的负应变与传感器灵敏度之间的关系进行了研究,该传感器基于根据膜的着色变化而评估的空间响应。我们的结果表明,与未应变的传感器相比,负应变有助于将传感器的灵敏度提高多达15倍。此外,在不到一分钟的暴露时间内即可达到90%的平衡响应,可快速诊断VOC。我们对传感器的可逆性进行的测试表明,可以多次使用CLC模板的聚合物薄膜,而不会显着降低灵敏度。我们基于胆甾醇间距的负应变与传感器灵敏度之间的关系进行了研究,该传感器基于根据膜的着色变化而评估的空间响应。我们的结果表明,与未应变的传感器相比,负应变有助于将传感器的灵敏度提高多达15倍。此外,在不到一分钟的暴露时间内即可达到90%的平衡响应,从而可以快速诊断VOC。我们对传感器的可逆性进行的测试表明,可以多次使用CLC模板的聚合物薄膜,而不会显着降低灵敏度。我们的结果表明,与未应变的传感器相比,负应变有助于将传感器的灵敏度提高多达15倍。此外,在不到一分钟的暴露时间内即可达到90%的平衡响应,从而可以快速诊断VOC。我们对传感器的可逆性进行的测试表明,可以多次使用CLC模板的聚合物薄膜,而不会显着降低灵敏度。我们的结果表明,与未应变的传感器相比,负应变有助于将传感器的灵敏度提高多达15倍。此外,在不到一分钟的暴露时间内即可达到90%的平衡响应,从而可以快速诊断VOC。我们对传感器的可逆性进行的测试表明,可以多次使用CLC模板的聚合物薄膜,而不会显着降低灵敏度。
更新日期:2020-07-29
down
wechat
bug