Transparent Materials Top-Down Constructed by Using\nAnimal Skins for Light Management Application

With the continuous consumption of\nnonrenewable resources, the\nincreasing shortage of energy, and the gradual aggravation of environmental\npollution, the research and development of biomass-based transparent\nmaterials (TM) with the potential to replace traditional glass and\nplastics has already been a hot and difficult point in the field of\nbiomass materials. Herein, a novel TM, called transparent leather\n(TL), was constructed by using goatskin, following a top-down strategy.\nSpecifically, goatskin was first impregnated in a mixed solution containing\nmonomer (2-hydroxyethyl acrylate (HEA)) and cross-linking agent (<i>N</i>,<i>N</i>′-methylene diacrylamide (MBA)),\nand then the hot-pressure <i>in situ</i> free-radical polymerization\nof HEA and MBA was conducted in the gaps of goatskin collagen fibers,\nwhich leads to the network interpenetrating structure containing the\nthree-dimensional woven network of collagen fibers and the network\nof polymer chains of poly(2-hydroxyethyl acrylate), and thus the formation\nof TL. Due to the dense filling of the polymer network and the reinforcement\nof goatskin’s collagen fibers framework, the resulting TL exhibited\nexcellent tensile strength (31.78 MPa) and transmittance (85%), excellent\nflexibility, impact resistance, and degradability. The excellent mechanical\nand optical properties of TL were derived from the dense interpenetrating\nnetwork structure formed by the collagen fiber network and the refractive\nindex-matched polymer network, as well as the abundant hydrogen-bonding\ninteractions present in the system. Further, fluorescent TL was prepared\nby doping carbon quantum dots with blue and yellow fluorescence in\nthe impregnation solution, which can be used as the light conversion\nlayer and assembled with LED chips to realize effective light conversion.\nThis work skillfully utilizes the natural multilevel biological structure\nof animal skin to provide a novel strategy for the preparation of\ngreen, renewable, and degradable TM, which can effectively broaden\nthe application fields of novel TM and alleviate the energy crisis\nand environmental hazards brought by the traditional TM.