Bio-Based Waterborne Poly(Vanillin-Butyl Acrylate)/MXene Coatings for Leather with Desired Warmth Retention and Antibacterial Properties

This study presents a solvent-free,facile synthesis of a bio-based green antibacterial agent and aromatic monomer methacrylated vanillin(MV)using vanillin.The resulting MV not only imparted antibacterial properties to coatings layered on leather,but could also be employed as a green alternative to petroleum-based carcinogen styrene(St).Herein,MV was copolymerized with butyl acrylate(BA)to obtain waterborne bio-based P(MV-BA)miniemulsion via miniemulsion polymerization.Subsequently,MXene nanosheets with excellent photothermal conversion performance and antibacterial properties,were introduced into the P(MV-BA)miniemulsion by ultrasonic dispersion.During the gradual solidification of P(MV-BA)/MXene nanocomposite miniemulsion on the leather surface,MXene gradually migrated to the surface of leather coatings due to the cavitation effect of ultrasonication and amphiphilicity of MXene,which prompted its full exposure to light and bacteria,exerting the maximum photothermal conversion efficiency and significant antibacterial efficacy.In particular,when the dosage of MXene nanosheets was 1.4 wt%,the surface temperature of P(MV-BA)/MXene nanocomposite miniemulsioncoated leather(PML)increased by about 15℃ in an outdoor environment during winter,and the antibacterial rate against Escherichia coli and Staphylococcus aureus was nearly 100%under the simulated sunlight treatment for 30 min.Moreover,the introduction of MXene nanosheets increased the air permeability,water vapor permeability,and thermal stability of these coatings.This study provides a new insight into the preparation of novel,green,and waterborne bio-based nanocomposite coatings for leather,with desired warmth retention and antibacterial properties.It can not only realize zerocarbon heating based on sunlight in winter,reducing the use of fossil fuels and greenhouse gas emissions,but also improve ability to fight off invasion by harmful bacteria,viruses,and other microorganisms.

Recent Advances in Ultrafine Fibrous Materials for Effective Warmth Retention

Extremely cold environment has led to a variety of serious public health issues and posed huge burden on the social econ-omy,which is an urgent challenge to the human worldwide.Featured with comfort,convenience,and cost-effectiveness,fibrous materials have been selected as heat insulation materials to protect the human body against the cold for centuries.The advanced ultrafine fibers,with remarkable softness,small average diameter and pore size,and high porosity,have found extensive attention,as promising candidate for application in reducing the heat loss.In this review,the heat transfer mechanisms for single fiber and fiber assembly are provided,and the typical categories of ultrafine fibrous materials for warmth retention,classified as fibrous membrane and fibrous sponge in terms of aggregate structures,are systematically summarized.In particular,this review comprehensively discusses the fabrication strategies,structure characteristics,and significant properties of various ultrafine fibrous materials.Finally,the current challenges and future development prospects of ultrafine fibrous materials for effective warmth retention are highlighted.