Lv Hui-Peng, Li Yi-Rong, Song Xian-Jiang, Zhang Nan, Xiong Ren-Gen, Zhang Han-Yue
Ordered Matter Science Research Center, Nanchang University, Nanchang330031, People's Republic of China.
State Key Laboratory of Bioelectronics, Southeast University, Nanjing210096, People's Republic of China.
J Am Chem Soc. 2023 Feb 8;145(5):3187-3195. doi: 10.1021/jacs.2c12951. Epub 2023 Jan 26.
Supramolecular host-guest ferroelectrics based on solution processing are highly desirable because they are generally created with intrinsic piezoelectricity/ferroelectricity and do not need further poling. Poly(vinylidene fluoride) (PVDF) in the electric-active beta phase after stretching/annealing still shows no piezoelectric response unless poled. Although many supramolecular host-guest ferroelectrics have been discovered, their piezoelectricity is relatively small. Based on H/F substitution, we reported a supramolecular host-guest compound [(CF-CH-NH)(18-crown-6)][TFSA] (CF-CH-NH = 4-trifluoromethylanilinium, TFSA = bis(trifluoromethanesulfonyl)ammonium) with a remarkable piezoelectric response of 42 pC/N under no poling condition. The introduction of F atoms increases phase transition temperature, polar axes, second harmonic generation (SHG) intensity, and piezoelectric coefficient . To our knowledge, such a large piezoelectric performance of [(CF-CH-NH)(18-crown-6)][TFSA] makes its , piezoelectric voltage coefficient , and mechanical quality factor the highest among the reported supramolecular host-guest ferroelectric compounds and even larger than the values of PVDF. This work provides inspiration for optimizing piezoelectricity on molecular materials.
基于溶液加工的超分子主客体铁电体非常理想，因为它们通常具有本征压电性/铁电性，无需进一步极化。拉伸/退火后处于电活性β相的聚偏二氟乙烯（PVDF），除非进行极化，否则仍无压电响应。尽管已发现许多超分子主客体铁电体，但其压电性相对较小。基于H/F取代，我们报道了一种超分子主客体化合物[(CF-CH-NH)(18-冠醚-6)][TFSA]（CF-CH-NH = 4-三氟甲基苯胺鎓，TFSA = 双（三氟甲磺酰）铵），在未极化条件下具有42 pC/N的显著压电响应。F原子的引入提高了相变温度、极轴、二次谐波产生（SHG）强度和压电系数。据我们所知，[(CF-CH-NH)(18-冠醚-6)][TFSA]如此大的压电性能使其压电电压系数和机械品质因数在已报道的超分子主客体铁电化合物中最高，甚至大于PVDF的值。这项工作为优化分子材料的压电性提供了灵感。
