Cold protection made easy: A fiber-based fabric with enhanced sunlight absorption and unidirectional sweat transport

In cold climates, maintaining body temperature with conventional fabrics becomes increasingly challenging, while the negative impact of heavy clothing on outdoor work is becoming more pronounced, prompting the development of new lightweight insulating fabrics. Herein, a bilayer fabric MnOOH-NPs/polydopamine/cotton-Maillard reaction zein (MPC-MRZ) with reinforced full-spectrum sunlight absorption and asymmetric wettability is reported. With a thickness similar to cotton, MPC-MRZ exhibits superior insulation, unidirectional sweat transport, and UV resistance without relying on external energy. Both lab and outdoor tests demonstrate exceptional sensitivity and rapid photothermal conversion (similar to 83.7 % sunlight absorption), resulting in a notable 10.15 degree celsius temperature compared with cotton. The Maillard reaction-induced cross-linking significantly boosts MRZ side hydrophobicity to 119.3 degrees, leading to substantial asymmetric wetting (0 degrees on MPC side) at heterogeneous interfaces. This enables rapid transportation of sweat to the external environment (3.83 s) without reverse penetration, and in conjunction with photothermal conversion, maintains surface dryness and wet comfort for sustained thermal insulation. Overall, this work aims at the comfort of human body, effectively combines thermal insulation and humidity control, which has a good application prospect in plateau areas.