Nanogels Containing Gold Nanoparticles on Cotton Fabrics for Comfort Control via Localized Surface Plasmon Resonance

The wearing comfort of fabrics is strongly related to moisture permeability and thermal insulation. To enhance comfort, the localized surface plasmon resonance (LSPR) effect is applied on cotton fabrics by densely packed hybrid nanogels containing gold nanoparticles on the surface. The nanogels are prepared by emulsion polymerization using di(ethylene glycol) methyl ether methacrylate (MEO2MA), (ethylene glycol) methyl ether methacrylate (OEGMA300), and ethylene glycol methacrylate (EGMA) as monomers. Because of the different transition temperatures of MEO2MA (25 °C) and OEGMA300 (60 °C), the obtained nanogels present a linear shrinkage behavior between 20 to 50 °C. Further treated with in situ reduction, gold nanoparticles (Au NPs) are embedded in the nanogels. After cross-linking the hybrid nanogels onto cotton fabrics and exposure to visible light irradiation (0.1029 W), the ratio of moisture permeability of the cotton fabrics cross-linked with hybrid nanogels (weight gain ratio, WGR of 8%) at 30 °C to that at 20 °C is 1.67. It is 45% better than that of cross-linked pure nanogels without any Au NPs. When the WGR is increased to 15%, the ratio is up to 2.18, thereby almost doubling that of the cross-linked pure nanogels. Such improvement is caused by the LSPR effect from the densely packed hybrid nanogels on the cotton fabric, which induces a more efficient photothermal conversion and prominent shrinkage of the hybrid nanogels. In addition, because the Au NPs can well absorb light irradiation, the cotton fabrics cross-linked with hybrid nanogels are able to efficiently shield the incident light and present a good capability of heat insulation. Therefore, the obtained cotton fabrics can adjust their comfort according to the external light conditions, well suited for outdoor scenarios such as running and hiking.