School of Chemistry and Chemical Engineering , Yangzhou University , Yangzhou , Jiangsu 225002 , China.
College of Materials Science and Engineering, Key Laboratory of Guangdong Province for High Property and Functional Polymer Materials , South China University of Technology , Guangzhou 510641 , P. R. China.
ACS Appl Mater Interfaces. 2019 Jul 10;11(27):24533-24543. doi: 10.1021/acsami.9b04304. Epub 2019 Jun 27.
Humidity and chemical vapor sensors have promising applications in the field of environment protection, human healthcare, and so forth. It is still challenging to develop sensor materials that can serve as both humidity and chemical vapor sensors with high sensitivity, low detection limit, and excellent stretchability, repeatability, and reliability. In this study, a flexible, stretchable, and conductive nanofiber composite (CNC) with superhydrophilicity and underwater superoleophobicity is prepared by acidified carbon nanotube (ACNT) decoration onto the thermoplastic polyurethane (PU) nanofiber surface. ACNT introduction increases both the Young's modulus and tensile strength and almost maintains the superelasticity of the PU nanofibrous membrane. The as-obtained CNC could be used to detect both moisture and chemical vapors. When used as the humidity sensor, ACNTs can absorb surrounding water molecules and thus increase their resistance. On the other hand, the PU can be swollen by different chemical vapors, which can, to a different extent, damage the conductive network inside the composite and cause the increase of the composite resistance. The CNC can be integrated with a mask for real-time detection of human respiration. The CNC-based chemical vapor sensor possesses low detection limit, quick response, good selectivity, and excellent recyclability (even in a high humid environment) and has potential applications in monitoring biomarker gases from human breath.
湿度和化学蒸气传感器在环境保护、人类健康等领域有广泛的应用前景。然而，开发出兼具高灵敏度、低检测限以及出色的拉伸性、可重复性和可靠性的湿度和化学蒸气传感器材料仍然具有挑战性。在这项研究中，通过在热塑性聚氨酯（PU）纳米纤维表面修饰酸化碳纳米管（ACNT），制备了一种具有超亲水性和水下超疏油性的柔性、可拉伸和导电纳米纤维复合材料（CNC）。引入 ACNT 不仅提高了杨氏模量和拉伸强度，而且几乎保持了 PU 纳米纤维膜的超弹性。所获得的 CNC 可用于检测水分和化学蒸气。当用作湿度传感器时，ACNTs 可以吸收周围的水分子，从而增加其电阻。另一方面，PU 可以被不同的化学蒸气溶胀，这在不同程度上会破坏复合材料内部的导电网络，导致复合材料电阻的增加。CNC 可以与口罩集成，用于实时检测人体呼吸。基于 CNC 的化学蒸气传感器具有低检测限、快速响应、良好的选择性以及出色的可回收性（即使在高湿度环境中），在监测人体呼吸生物标志物气体方面具有潜在的应用。
