Converting Light Into Programmable Temperatures via Janus Hydrogels for Passive Infrared Thermography.

Passive thermal management saves energy using natural processes but struggles with precise temperature control in variable environments. This study designs and synthesizes temperature-programmable hydrogels (TPH) based on a bilayer polyvinyl alcohol network with tunable passive heating capacity. The TPH features an upper layer with adjustable transmittance (6.

Super-Stretchable Hybrid Aerogels by Self-Templating Strategy for Cross-Media Thermal Management.

Personal thermal management (PTM) materials have attracted increasing attention owing to their application for personal comfort in an energy-saving mode. However, they normally work in the same media such as in the air, and little is known about what will happen in other media like water. In this study, a system for cross-media thermal management (CMTM): passive cooling in air and thermal insulation underwater is proposed.

Bioinspired Multilayer Structures for Energy-Free Passive Heating and Thermal Regulation in Cold Environments.

Passive thermal regulation has attracted increasing interest owing to its zero-energy consumption capacity, which is expected to alleviate current crises in fossil energy and global warming. In this study, a biomimetic multilayer structure (BMS) comprising a silica aerogel, a photothermal conversion material (PTCM), and a phase change material (PCM) layer is designed inspired by the physiological skin structure of polar bears for passive heating with desirable temperature and endurance. The transparent silica aerogel functions as transparent hairs and allows solar entry and prevents heat dissipation; the PTCM, a glass plate coated with black paint, acts as the black skin to convert the incident sunlight into heat; and the PCM composed of -octadecane microcapsules stores the heat, regulating temperature and increasing endurance.

Aerogel-Functionalized Thermoplastic Polyurethane as Waterproof, Breathable Freestanding Films and Coatings for Passive Daytime Radiative Cooling.

Passive daytime radiative cooling (PDRC) is an emerging sustainable technology that can spontaneously radiate heat to outer space through an atmospheric transparency window to achieve self-cooling. PDRC has attracted considerable attention and shows great potential for personal thermal management (PTM). However, PDRC polymers are limited to polyethylene, polyvinylidene fluoride, and their derivatives.