Nacre-bionic nanocomposite membrane for efficient in-plane dissipation heat harvest under high temperature
Jiemin Wang, Dan Liŭ, Quanxiang Li, Cheng Chen, Zhiqiang Chen, Minoo Naebe, Pingan Song, David Portehault, Christopher J. Garvey, Dmitri Golberg, Weiwei Lei
Abstract
Waste heat management holds great promise to create a sustainable and energy-efficient society as well as contributes to the alleviation of global warming. Harvesting and converting this waste heat in order to improve the efficiency is a major challenge. Here we report biomimetic nacre-like hydroxyl-functionalized boron nitride (BN)-polyimide (PI) nanocomposite membranes as efficient 2D in-plane heat conductor to dissipate and convert waste heat at high temperature. The hierarchically layered nanostructured membrane with oriented BN nanosheets gives rise to a very large anisotropy in heat transport properties, with a high in-plane thermal conductivity (TC) of 51 W m−1 K−1 at a temperature of ∼300 °C, 7314% higher than that of the pure polymer. The membrane also exhibits superior thermal stability and fire resistance, enabling its workability in a hot environment. In addition to cooling conventional exothermic electronics, the large TC enables the membrane as a thin and 2D anisotropic heat sink to generate a large temperature gradient in a thermoelectric module (ΔT = 23 °C) through effective heat diffusion on the cold side under 220 °C heating. The waste heat under high temperature is therefore efficiently harvested and converted to power electronics, thus saving more thermal energy by largely decreasing consumption.