Adaptive and Adjustable MXene/Reduced Graphene Oxide Hybrid Aerogel Composites Integrated with Phase-Change Material and Thermochromic Coating for Synchronous Visible/Infrared Camouflages

Abstract

Although single-function camouflage under infrared/visible bands has made great advances, it is still difficult for camouflage materials to cope with the synergy detection spanning both visible and infrared spectra and adapt to complex and variable scenarios. Herein, a trilayer composite integrating thermal insulation, heat absorption, solar/electro-thermal conversions, and thermochromism is fabricated for visible and infrared dual camouflages by combining anisotropic MXene/reduced graphene oxide hybrid aerogel with the n-octadecane phase change material in its bottom and a thermochromic coating on its upper surface. Benefiting from the synergetic heat-transfer suppression derived from the thermal insulation of the porous aerogel layer and the heat absorption of the n-octadecane phase-change layer, the composite can serve as a cloak to hide the target signatures from the infrared images of its ambient surroundings during the day in the jungle and at night in all scenes and can assist the target in escaping visual surveillance by virtue of its green appearance. For desert scenarios, the composite can spontaneously increase its surface temperature via its solar-thermal energy conversion, merging infrared images of the targets into the high-temperature surroundings; meanwhile, it can vary the surface color from the original green to yellow, enabling the target to visually disappear from ambient sands and hills. This work provides a promising strategy for designing adaptive and adjustable integrated camouflage materials to counter multiband surveillance in complicated environments.

Carbonized Syndiotactic Polystyrene/Carbon Nanotube/MXene Hybrid Aerogels with Egg-Box Structure: A Platform for Electromagnetic Interference Shielding and Solar Thermal Energy Management

“…Specifically, the Raman spectrum of CM-4-6 obviously shows the D-band (1373 cm –1 ) and G-band (1601 cm –1 ) of CNTs (Figure f). In addition, the Raman spectra presented the A 1g vibrations of Ti atoms (199 cm –1 ) and C atoms (712 cm –1 ), and the E g vibrations of Ti atoms (266 cm –1 ), C atoms (376 cm –1 ), and the surface termination (620 cm –1 ). , …”

“…Interlayer spacers were usually introduced to solve the above-mentioned issues. For instance, zero-dimensional (0D) nanoparticles, − one-dimensional (1D) nanotubes/nanowires, ,,, 2D nanosheets, − or a combination of these materials − have been incorporated between MXene layers. For practical purposes, MXene-based EMI shielding materials were fabricated using layer-by-layer assembly techniques, ,,, freeze-casting, ,,,, and segregated compositing. − …”

“…Meanwhile, MXene possesses other appealing properties, including advanced thermal, optical, and hydrophilic surface functionalities. ,, Therefore, beyond EMI shielding, MXene-based composites were designed with multifunctionalities. For instance, high-efficiency EMI shielding and heat dissipation synergy materials were achieved by the lamellar MXene/aramid nanofiber (ANF) composite films with a nacre-like structure .…”

2D nanomaterial aerogels integrated with phase change materials: a comprehensive review

“…MXene-based composite PCMs have also been used as a promising solution for dual-camouflage under infrared/visible bands. To this end, Li et al 272 have fabricated a trilayer composite that integrates key features such as thermal insulation, heat absorption, solar/electro-thermal conversions, and thermochromism. This innovative composite consists of an anisotropic Ti 3 C 2 T x /rGO hybrid aerogel, with n-octadecane PCM at the bottom and a thermochromic coating on the upper surface.…”

Dual-functional reduced graphene oxide decorated nanoporous polytetrafluoroethylene metafabrics for radiative cooling and solar-heating

“…10 For normal human skin with a surface temperature of 36 °C, the wavelength of human body infrared radiation (HBIR) mainly ranges between 7 and 14 μm with a peak at 9.5 μm. 30,31 Radiative thermal management can realize extraordinary cooling performances by dissipating metabolic heat to the outside directly via regulating the transmittance and emissivity of the fabric in the HBIR range, 32 which has many advantages over traditional ways. 33–39 Based on their working mechanisms, radiative cooling fabrics can be divided into high-emission type and high transparency-type.…”