# Direct Observation of Tunable Thermal Conductance at Solid/porous Crystalline Solid Interfaces Induced by Water Adsorbents

## TL;DR

This study demonstrates that water adsorption in porous MOFs can significantly enhance interfacial thermal conductance, offering a new method to control heat transfer at solid/porous interfaces for improved thermal management.

## Contribution

It introduces a novel strategy using water adsorption-desorption in MOFs to tunably enhance interfacial thermal conductance, supported by experimental and molecular dynamics simulation results.

## Key findings

- Thermal conductance increased up to 7.1 times using water adsorption.
- Dense water channels activate high-frequency lattice vibrations.
- Water acts as an additional thermal pathway at the interface.

## Abstract

Improving interfacial thermal transport is crucial for heat dissipation in systems. Here, we design a strategy by utilizing the water adsorption-desorption process in porous metal-organic frameworks (MOFs) to tune the interfacial heat transfer. We observe a changeable thermal conductance across the solid/porous MOFs interfaces owing to the dense water channel formed by the adsorbed water molecules in MOFs. Our experimental results show that the interfacial thermal conductance of Au/Cu3(BTC)2 heterointerfaces is increased up to 7.1 folds by this strategy, where Cu3(BTC)2 is a typical porous MOF and usually referred to as HKUST-1. Our molecular dynamics simulations further show that the surface tension of Au layer will cause the adsorbed water molecules in HKUST-1 to gather at the interfacial region. The dense water channel formed at the interfacial region can activate the high-frequency lattice vibrations and act as an additional thermal pathway, and then enhance heat transfer across the interfaces significantly. Our findings provide a new concept for tailoring thermal transport at the solid/porous MOFs heterointerfaces which will largely benefit MOF-related applications.

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Source: https://tomesphere.com/paper/2302.11987