High-enthalpy aramid nanofiber aerogel-based composite phase change materials with enhanced thermal conductivity

Abstract

Solid-liquid phase change materials (PCMs) have the advantages of easy adjustment of the phase transition temperature, high heat enthalpy, and small volume change, which endow them with great application potential in thermal management. However, problems such as low thermal conductivity, inherent stiffness, and liquid flow of solid-liquid PCMs limit their functional applications. Herein, high-enthalpy composite PCMs supported by polymer aerogel are reported, which can prevent long-range crystallization and provide shape stability before and after phase transition. In this work, aramid nanofiber (ANF) aerogel was used as the carrier, polyethylene glycol (PEG) was used as the PCMs, and the encapsulation of PEG in aerogel was realized by vacuum impregnation. The resulting polymer aerogel-based composite PCMs exhibit a large phase change enthalpy (175.1 J/g) at a PEG content of 95.4 wt%, accompanied by a good thermal conductivity of 1.03 W/m⋅k. Benefiting from the excellent phase change thermal management performance and temperature adjustability, the composite has promising applications in high-end electronic equipment, heat dissipation and pipeline insulation.