High temperature nanocomposites with photonic group velocity suppression of thermal emission

TL;DR

This paper introduces a novel nanocomposite material capable of suppressing thermal radiation at room and elevated temperatures by manipulating photonic modes, potentially impacting energy and space technologies.

Contribution

It presents a new flexible composite that quenches thermal emission while maintaining heat transfer, a feat not achieved at such temperatures before.

Findings

Suppresses propagating photonic modes to quench thermal radiation

Maintains heat transfer via thermal conduction at temperatures below 600 K

Alters local photonic density of states using carbon nanotube nanofibers

Abstract

Quenching of thermal emission above 0 K is an unusual material property, essential for future energy, transportation, and space technologies. Despite the great effort invested, nearly complete quenching of thermal radiation rather than some reduction of its flux has only been achieved at low temperatures (below 373 K) and in narrow spectral windows using complex techniques suitable only for small scale objects. In this work, we present a light and flexible composite material that can suppress propagating photonic modes and, in this way, quench thermal radiation while preserving heat transfer (by thermal conduction) at a room and higher temperature below 600 K. This has been achieved by altering the local photonic density of states and consequentially the thermal properties of carbon nanotubes forming a percolating nanofiber network with a thermostable polymeric matrix.