Wang Yuxin, Wang Haijun, Liu Kun, Wang Tong, Yuan Chunlei, Yang Haibo
Shaanxi University of Science and Technology Xi'an 710021 Shaanxi China
RSC Adv. 2021 Sep 15;11(49):30734-30743. doi: 10.1039/d1ra05667k. eCollection 2021 Sep 14.
Piezoelectric nanosensors were prepared with a novel type of dehydrofluorinated poly(vinylidene fluoride) (PVDF) nanofibrous membrane. With the synergistic effect of the dehydrofluorination reaction and applied high voltage electric field, the piezoelectric and energy storage properties of fibrous membranes attained great improvement. It was found that the simultaneous introduction of conjugated double bonds to the backbone of PVDF which was accompanied with the elimination of HF, resulted in the decrease of its molecular weight, solution viscosity and hydrophobicity. The crystalline phase, diameter, piezoelectric and energy storage properties of electro-spun PVDF nanofiber membranes significantly depend on the degree of HF elimination in dehydrofluorinated PVDF. The dehydrofluorinated PVDF with 5 hours of reaction exhibits the highest discharged energy density ( ) and energy storage efficiency (), but excessive dehydrofluorination reaction is unfavorable to the energy storage properties. In addition, the dehydrofluorinated PVDF fiber membrane-based nanosensor possesses a larger electrical throughput (open circuit voltage of 30 V, which is three time that of the untreated PVDF), indicating that the introduction of double bonds can also improve the piezoelectric properties of PVDF nanofibers.
采用新型脱氟化氢聚偏氟乙烯（PVDF）纳米纤维膜制备了压电纳米传感器。在脱氟化氢反应和外加高压电场的协同作用下，纤维膜的压电性能和储能性能得到了极大的改善。研究发现，在PVDF主链中同时引入共轭双键并伴随着HF的消除，导致其分子量、溶液粘度和疏水性降低。电纺PVDF纳米纤维膜的晶相、直径、压电性能和储能性能显著取决于脱氟化氢PVDF中的HF消除程度。反应5小时的脱氟化氢PVDF表现出最高的放电能量密度（ ）和储能效率（），但过度的脱氟化氢反应不利于储能性能。此外，基于脱氟化氢PVDF纤维膜的纳米传感器具有更大的电通量（开路电压为30 V，是未处理PVDF的三倍），这表明双键的引入也可以改善PVDF纳米纤维的压电性能。
