Preparation of Recyclable and Multifunctional Porous PLA (Polylactic Acid)/Cotton Fabric for Daytime Radiative Cooling

Passive radiative cooling is an innovative technology capable of cooling objects without the need for external energy input. It dissipates heat from objects into outer space (∼3 K) in the form of infrared radiation by using the atmospheric transparent window. Polymers are commonly applied in radiative cooling technology, but their nondegradability and limited functionality restrict their widespread application. In this paper, a porous polylactic acid (PLA)/cotton composite fabric, as a recyclable passive radiative cooling material, is prepared by a freeze-drying method. The incorporation of zinc oxide (ZnO) nanoparticles enhanced the fabric’s performance, achieving an emissivity of 87.92% and a reflectivity of 87.15%. Additionally, the porous composite fabric exhibited exceptional antibacterial properties, with antibacterial rates of 99.68% against Escherichia coli, 100% against Staphylococcus aureus, and 100% against Candida albicans. In addition, the porous PLA/cotton fabric also demonstrates excellent self-cleaning properties and chemical recyclability. This recyclable porous biomass with integrating antibacterial, self-cleaning, and radiative cooling functions will pave a sustainable way for developing sustainable passive radiative cooling fabric materials with multifunctions.