Thermal Transport in Interpenetrated Metal–Organic Frameworks

Abstract

In practice, the usefulness of metal–organic frameworks (MOFs) for many gas storage applications depends on their ability to rapidly dissipate the heat generated during the exothermic adsorption process. MOFs can be precisely designed to have a wide variety of architectures which can allow tuning their thermal conductivity. In this work, we use molecular dynamics simulations to investigate the effect of interpenetration on the thermal conductivity of MOFs. We find that the addition of a parallel thermal transport pathway yields a thermal conductivity nearly the sum of the two constituent frameworks. This relationship holds for a variety of interpenetrating MOFs with different atomic masses and a wide range of interframework interaction parameters. We show that both the strength and range of interactions between constituent frameworks play a significant role in framework mobility as well as framework coupling which can result in deviation from this relationship. We propose a simple model to predict thermal conductivity of the interpenetrated framework based on thermal conductivities of individual frameworks and an interframework interaction parameter which can account for this deviation.