In this research, piezoelectric and heat-dissipating boron nitride nanotube (BNNT)/polyvinylidene fluoride (PVDF) nanocomposite thin films having superior properties for wearable sensing applications are introduced. Neat and 2.5 wt % (BNNT2.5)- and 5.0 wt % BNNT (BNNT5.0)-embedded PVDF thin films were prepared by first producing gel-like electrospun nanofibers followed by hot-rolling, respectively. The piezoelectric performance of BNNT5.0 was as high as 128.0 ± 5.4 mV under 300 kPa, while Neat and BNNT2.5 showed 9.9 ± 0.1 and 22.7 ± 8.8 mV, respectively. Furthermore, BNNT2.5 also presents almost 9 times and BNNT5.0 presents more than 3 times higher thermal conductivities of 0.89 ± 0.40 and 0.32 ± 0.10 W/mK, respectively, compared to Neat (0.10 ± 0.01 W/mK) and both present very high thermal resistance with no phase change up to 180 °C and less than 4% shrinkage even at 200 °C, while Neat begins melting at 120 °C. BNNT2.5 and BNNT5 showed a high water-repelling property and mechanical strength as well. Tensile strengths and elongation for BNNT2.5 and BNNT5.0 were 18.1 MPa with 52.1% and 21.2 MPa and 34.0%, respectively. They both showed a low moisture absorption property with high water repellence with stable and hydrophobic water contact angles (92.2° with only 0.4° change for BNNT2.5 and 103.6° with 2.4° change for BNNT5.0 in 30 s), while Neat was in the hydrophilic region. Consequently, BNNT/PVDF films with highly enhanced piezoelectric-sensing and heat-dissipating properties and mechanical, thermal, and moisture resistance can be applicable for various wearable sensing environments.

中文翻译：

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适用于可穿戴压电传感器的氮化硼纳米管排列静电纺丝 PVDF 纳米纤维复合薄膜

在这项研究中，介绍了具有优异性能的压电散热氮化硼纳米管（BNNT）/聚偏二氟乙烯（PVDF）纳米复合薄膜，适用于可穿戴传感应用。首先生产凝胶状电纺纳米纤维，然后分别进行热轧，制备纯的、2.5 wt% (BNNT2.5) 和 5.0 wt% BNNT (BNNT5.0) 嵌入的 PVDF 薄膜。 BNNT5.0在300 kPa下的压电性能高达128.0±5.4 mV，而Neat和BNNT2.5分别表现出9.9±0.1和22.7±8.8 mV。此外，与 Neat (0.10 ± 0.01 W/mK) 相比，BNNT2.5 的热导率也高出近 9 倍，BNNT5.0 的热导率分别高出 3 倍以上，分别为 0.89 ± 0.40 和 0.32 ± 0.10 W/mK，并且两者均存在非常高的耐热性，高达 180 °C 时不会发生相变，即使在 200 °C 时收缩率也低于 4%，而 Neat 在 120 °C 时开始熔化。 BNNT2.5和BNNT5还表现出高防水性和机械强度。 BNNT2.5和BNNT5.0的拉伸强度和伸长率分别为18.1 MPa和52.1%，以及21.2 MPa和34.0%。它们均表现出低吸湿性、高拒水性以及稳定且疏水的水接触角（BNNT2.5 为 92.2°，30 秒内仅变化 0.4°；BNNT5.0 为 103.6°，30 秒内变化 2.4°）。在亲水区域。因此，具有高度增强的压电传感和散热性能以及机械、耐热和防潮性能的BNNT/PVDF薄膜可适用于各种可穿戴传感环境。