Self‐Contained Moisture Management and Evaporative Cooling Through 1D to 3D Hygroscopic All‐Polymer Composites

Abstract

Sorption‐based moisture management and evaporative cooling represent emerging technologies with substantial potential for energy‐saving personal thermal management (PTM). However, design of high‐performance and durable hygroscopic composites combining efficient heat dissipation with wearing comfort presents significant challenges. Herein, hygroscopic 1D nanofibers and 2D fabrics are developed using two hygroscopic polymers and crosslinking strategies. The design endows the fabrics with self‐contained properties including excellent hygroscopicity, durability, ductility, breathability, washability, and antimicrobial capability. The fabrics exhibit thickness‐independent moisture sorption and equilibrium water uptake of 1.19 g g−1 in 4 h under 90% relative humidity (RH). About 80% of the absorbed water can be rapidly released through mild heating within 10 min. These high moisture sorption/desorption rates outperform the majority of composite desiccants, enabling up to five sorption/desorption cycles per day under a real sky. The hygroscopic fabrics can reduce apparent temperatures and prevent unsightly sweat stains on clothing, improving thermal and clothing comfort. Furthermore, hygroscopic 3D hierarchical matrices are printed, showcasing the potential to use small amounts of hygroscopic materials to boost moisture sorption. This work advances the controlled fabrication of hygroscopic polymer composites, ranging from 1D nanofibers and 2D fabrics to 3D matrices, highlighting their promising prospects for future sorption‐based PTM applications.

Foaming photothermal inks for direct-ink writing: hierarchical design and enhanced solar-powered interfacial evaporation

“…Our recent reports have evidenced that CNFs served as an important constituent within the printable ink formulation. 83,84 The excellent shear-thinning property and mechanical strength of CNFs played a role in the formation of self-supporting microfilaments and the stabilization of intricate 3D structures, highlighting the significance of CNFs in ensuring the printability of foaming photothermal inks.…”

Macroporous, Highly Hygroscopic, and Leakage-Free Composites for Efficient Atmospheric Water Harvesting

“…The emulsions were initially solidified through the formation of a semi-IPN, where SA was interpenetrated in the PVA macromolecular network that was created via formation of PVA crystals during the freeze–thawing process . Upon immersing in an aqueous solution of CaCl 2 , the interpenetrated SA was physically cross-linked by creating an “egg box” upon contacting Ca 2+ , transferring the semi-IPN into IPNs . The IPNs are actually formed through hierarchically physical cross-linking (PVA crystallization and SA gelation), and to our knowledge, emulsion-templated hydrophilic polymers with IPNs have not been explored yet.…”

“…39 Upon immersing in an aqueous solution of CaCl 2 , the interpenetrated SA was physically cross-linked by creating an "egg box" upon contacting Ca 2+ , transferring the semi-IPN into IPNs. 40 The IPNs are actually formed through hierarchically physical cross-linking (PVA crystallization and SA gelation), and to our knowledge, emulsion-templated hydrophilic polymers with IPNs have not been explored yet. The IPNs are believed to provide advantageous properties to the resulting hygroscopic composites.…”

Self-Assembly Reinforced Alginate Fibers for Enhanced Strength, Toughness, and Bone Regeneration

“…Naturally abundant sodium alginate (SA) is a linear polysaccharide extracted from brown seaweeds . The molecular units of β-D-mannuronic acid (M unit) and α-L-guluronic acid (G unit) ensure SA free of neurotoxicity, good biocompatibility, and biodegradability. − These features endow alginate fibers excellent characteristics including skin-friendliness, moisture absorption, antibacterial, as well as renewability. , Alginate fibers become ideal candidates for rapid wound healing, cosmetics, environmental protection, tumor therapy, and other fields. − Compared with other biobased fibers, the relatively lower mechanical property limits their applications.…”