Tunable Piezoelectricity of Multifunctional Boron Nitride Nanotube/Poly(dimethylsiloxane) Stretchable Composites
Tunable Piezoelectricity of Multifunctional Boron Nitride Nanotube/Poly(dimethylsiloxane) Stretchable Composites
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DOI：
10.1002/adma.202004607
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发表时间：
2020-09-21
影响因子：
29.4
通讯作者：
Park, Cheol
中科院分区：
文献类型：
--
作者：
Snapp, Peter;Cho, Chullhee;Park, Cheol
氮化硼纳米管（BNNT）均匀地分散在可拉伸材料中，如聚二甲基硅氧烷（PDMS），可以创造出具有增强机械、热学和压电特性的下一代复合材料。该研究报告了通过与四氢呋喃（THF）共溶剂共混制备的多功能BNNT/PDMS可拉伸复合材料的可调谐压电性，以分散BNNT在PDMS中，同时避免超声或功能化。所得的可拉伸BNNT/PDMS复合材料具有增强的杨氏模量（在9 wt% BNNT时增加200%）和导热系数（在9 wt% BNNT时增加120%）而不失去拉伸性。此外，BNNT/PDMS复合材料显示出与BNNT wt%成线性比例的压电响应，在没有极化的情况下，在BNNT wt%时实现18 pmV（-1）的压电常数（|d(33)|），这与商用压电聚合物具有竞争力。独特的是，BNNT/PDMS可以通过调整BNNT来适应高达60%的拉伸应变而不会产生塑性变形，这将复合材料的压电响应提高了大约五倍。最后，利用复合材料的可拉伸和压电特性来制造对低频（接近1 kHz）激励敏感的振动传感器。这是多功能、可拉伸的BNNT/PDMS复合材料的首次演示，该复合材料具有增强的机械强度和导热性，并且通过改变BNNT wt%和施加应变可调谐压电响应，允许应用于软致动器和振动传感器。
Boron nitride nanotubes (BNNT) uniformly dispersed in stretchable materials, such as poly(dimethylsiloxane) (PDMS), could create the next generation of composites with augmented mechanical, thermal, and piezoelectric characteristics. This work reports tunable piezoelectricity of multifunctional BNNT/PDMS stretchable composites prepared via co-solvent blending with tetrahydrofuran (THF) to disperse BNNTs in PDMS while avoiding sonication or functionalization. The resultant stretchable BNNT/PDMS composites demonstrate augmented Young's modulus (200% increase at 9 wt% BNNT) and thermal conductivity (120% increase at 9 wt% BNNT) without losing stretchability. Furthermore, BNNT/PDMS composites demonstrate piezoelectric responses that are linearly proportional to BNNT wt%, achieving a piezoelectric constant (|d(33)|) of 18 pmV(-1)at 9 wt% BNNT without poling, which is competitive with commercial piezoelectric polymers. Uniquely, BNNT/PDMS accommodates tensile strains up to 60% without plastic deformation by aligning BNNTs, which enhances the composites' piezoelectric response approximately five times. Finally, the combined stretchable and piezoelectric nature of the composite was exploited to produce a vibration sensor sensitive to low-frequency (approximate to 1 kHz) excitation. This is the first demonstration of multifunctional, stretchable BNNT/PDMS composites with enhanced mechanical strength and thermal conductivity and furthermore tunable piezoelectric response by varying BNNT wt% and applied strain, permitting applications in soft actuators and vibration sensors.