Zhang Zhibo, Bolshakov Andrey, Han Jiecai, Zhu Jiaqi, Yang Kun-Lin
National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin 150080, P. R. China.
Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117576 Singapore, Singapore.
ACS Appl Mater Interfaces. 2023 Mar 14. doi: 10.1021/acsami.2c23065.
Electrospun polymer-liquid crystal (PLC) fibers have potential applications such as wearable sensors and adaptive textiles because of their rapid response and high flexibility. However, existing PLC fibers only have a narrow responsive range and poor resistance to heat and chemicals. Herein, a new type of PLC fiber is prepared by using a coaxial electrospinning process. The core solution is 4'-pentyl-4-biphenylcarbonitrile (5CB), and the sheath solution is a mixture containing 13 wt % PVP and 10 wt % reactive mesogen (RM). After UV exposure of the fibers, 5CB in the core and RM diffusing from the core are cross-linked into an LC polymer. The fibers have a highly uniform morphology with an average diameter of 3.2 ± 0.5 μm, and mesogens inside the fibers align unidirectionally with the long axis of the fibers. The fibers show a broad phase-transition temperature range between 13.5 and 155.5 °C and have a response time of less than 10 s. The temperature range can also be controlled by adjusting components in the electrospun fibers and UV exposure time. The core-sheath fibers prepared in such a manner exhibit excellent heat and chemical resistance with reversible optical responses. Moreover, when the fibers are exposed to volatile organic compounds (VOCs) such as toluene, the fibers show a rapid optical response to toluene vapor within 25 s. This study demonstrates that the fibers are potentially useful for preparing flexible temperature and chemical sensors.
静电纺丝聚合物-液晶（PLC）纤维因其快速响应和高柔韧性而具有诸如可穿戴传感器和自适应纺织品等潜在应用。然而，现有的PLC纤维仅具有狭窄的响应范围以及较差的耐热性和耐化学性。在此，通过同轴静电纺丝工艺制备了一种新型的PLC纤维。芯溶液为4'-戊基-4-联苯甲腈（5CB），鞘溶液是含有13 wt%聚乙烯吡咯烷酮（PVP）和10 wt%反应性液晶基元（RM）的混合物。纤维经紫外线照射后，芯部的5CB和从芯部扩散出来的RM交联形成一种液晶聚合物。这些纤维具有高度均匀的形态，平均直径为3.2±0.5μm，并且纤维内部的液晶基元沿纤维长轴单向排列。这些纤维在13.5至155.5°C之间呈现出较宽的相变温度范围，响应时间小于10秒。该温度范围也可通过调整静电纺丝纤维中的组分和紫外线照射时间来控制。以这种方式制备的核壳纤维表现出优异的耐热性和耐化学性以及可逆的光学响应。此外，当纤维暴露于甲苯等挥发性有机化合物（VOCs）时，纤维在25秒内对甲苯蒸气表现出快速的光学响应。这项研究表明，这些纤维在制备柔性温度和化学传感器方面具有潜在用途。
