Department of Mechanical Engineering, Carnegie Mellon University (CMU), Pittsburgh, PA, 15213, USA.
Department of Mechanical and Nuclear Engineering, Pennsylvania State University, State College, PA, 16802, USA.
Nat Commun. 2018 Apr 25;9(1):1664. doi: 10.1038/s41467-018-03978-3.
Polymers are widely used in daily life, but exhibit low strength and low thermal conductivity as compared to most structural materials. In this work, we develop crystalline polymer nanofibers that exhibit a superb combination of ultra-high strength (11 GPa) and thermal conductivity, exceeding any existing soft materials. Specifically, we demonstrate unique low-dimensionality phonon physics for thermal transport in the nanofibers by measuring their thermal conductivity in a broad temperature range from 20 to 320 K, where the thermal conductivity increases with increasing temperature following an unusual ~T trend below 100 K and eventually peaks around 130-150 K reaching a metal-like value of 90 W m K, and then decays as 1/T. The polymer nanofibers are purely electrically insulating and bio-compatible. Combined with their remarkable lightweight-thermal-mechanical concurrent functionality, unique applications in electronics and biology emerge.
聚合物在日常生活中被广泛应用，但与大多数结构材料相比，其强度和热导率较低。在这项工作中，我们开发出结晶聚合物纳米纤维，具有超高强度（11GPa）和热导率的绝佳组合，超过任何现有软材料。具体来说，我们通过在 20 至 320K 的宽温度范围内测量其热导率，证明了纳米纤维中热输运的独特低维声子物理，其中热导率在低于 100K 时随温度升高呈不寻常的~T 趋势增加，最终在 130-150K 左右达到类似金属的值 90WmK，然后随 1/T 衰减。聚合物纳米纤维是纯电绝缘和生物相容的。结合其显著的轻质-热机械协同功能，在电子学和生物学中出现了独特的应用。
