Nanofibrous Kevlar Aerogel Films and Their Phase-Change Composites for Highly Efficient Infrared Stealth

TLDR

Infrared stealth is critical for modern military and material science, yet effectively concealing targets from thermal detectors remains a major challenge. The study proposes combined Kevlar nanofiber aerogel insulation layers and KNA/PCM ultralow‑IR‑transmittance layers to hide hot targets from infrared detection. Flexible, foldable Kevlar nanofiber aerogel films with high porosity and surface area were fabricated and incorporated with phase‑change materials such as polyethylene glycol to create KNA/PCM composite films. The KNA/PCM films and combined KNA–KNA/PCM structures exhibit high thermal management, infrared emissivity matching various backgrounds, and render hot targets completely invisible in infrared images, demonstrating strong potential for infrared stealth applications.

Abstract

Infrared (IR) stealth is essential not only in high technology and modern military but also in fundamental material science. However, effectively hiding targets and rendering them invisible to thermal infrared detectors have been great challenges in past decades. Herein, flexible, foldable, and robust Kevlar nanofiber aerogel (KNA) films with high porosity and specific surface area were fabricated first. The KNA films display excellent thermal insulation performance and can be employed to incorporate with phase-change materials (PCMs), such as polyethylene glycol, to fabricate KNA/PCM composite films. The KNA/PCM films with high thermal management capability and infrared emissivity comparable to that of various backgrounds demonstrate high performance in IR stealth in outdoor environments with solar illumination variations. To further realize hiding hot targets from IR detection, combined structures constituted of thermal insulation layers (KNA films) and ultralow IR transmittance layers (KNA/PCM) are proposed. A hot target covered with this combined structure becomes completely invisible in infrared images. Such KNA/PCM films and KNA-KNA/PCM combined structures hold great promise for broad applications in infrared thermal stealth.