Fabrication of MnO2 nanowires@Ag/cellulose laminated membrane with unidirectional liquid penetration for personal thermal management applications

Abstract

\n Controllable and reliable fabrication of wearable materials with tunable structures and integrated functionalities are urgently required for personal thermal management. Herein, this highlight presents the fabrication of MnO2 nanowires@Ag/cellulose laminated membrane with infrared insulation, antibacterial and unidirectional liquid penetration properties via orderly vacuum filtration of hydrophobic cellulose, hydrophilic cellulose and ultra-long MnO2 nanowires coated with silver (MnO2 nanowires@Ag). To do this, hydrophobic sugarcane cellulose was obtained by surface modification with silane coupling agent (A151), while hydrophilic sugarcane cellulose was obtained by HNO3 treatment. Silver coated MnO2 nanowires, as the building blocks of laminated membranes, were prepared by magnetron sputtering of silver nanoparticles onto the surfaces of MnO2 nanowires. The characterizations indicated that silver nano coating with high infrared radiation reflectivity and excellent electrical conductivity were successfully fabricated onto MnO2 nanowires surfaces, resulting in infrared insulation properties of the laminated cellulose membranes. In addition, the laminated membranes exhibit excellent unidirectional liquid penetration properties that can enhance the wearing comfort for the laminated cellulose membranes. In the antibacterial tests against Escherichia coli and Staphylococcus aureus, the laminated membranes exhibit large diameters of inhibition zones, revealing the high antibacterial activity. Moreover, excellent electrical conductivity of silver coating grants the superior Joule heating, generating rapid thermal response and uniform electrical heating at low supply voltage for extra warmth. These results indicate a promising potential of the laminated cellulose membranes for tackling personal thermal management issues related to wearable applications.