Wet-resilient graphene aerogel for thermal conductivity enhancement in polymer nanocomposites

Abstract

Three-dimensional (3D) graphene-based aerogels have significant potential for adsorption, sensors, and thermal management applications. However, their practical applications are limited by their disorganized structure and ultra-low resilience after compression. Some methods can realize a well-aligned structure, however, they involve high costs and complex technology. Herein, a 3D graphene hybrid aerogel with an anisotropic open-cell and well-oriented structure is realized by unidirectional freeze casting, which combines the ‘soft’ (e.g. graphene oxide, Tween-80) and ‘hard’ (e.g. graphene assembly) components to realize full recovery after flattening. A graphene aerogel annealed at a moderate temperature (∼200 °C) can possess superhydrophilicity and outstanding wet-resilience properties, including after being pressed under 40 MPa. Furthermore, the graphene aerogel annealed at a high temperature of ∼1500 °C exhibits excellent thermal conductivity enhancement efficiency in polydimethylsiloxane (PDMS). The resultant nanocomposites clearly demonstrate anisotropic thermal conductivity and promising applications as thermal interface materials. This strategy offers new insights into the design and fabrication of 3D multifunctional graphene aerogels.