Due to the various needs in the current applications, multifunctional composite materials with high strength and high toughness were highly desired now. Many scholars dedicated their time to find a simple, green and f...Due to the various needs in the current applications, multifunctional composite materials with high strength and high toughness were highly desired now. Many scholars dedicated their time to find a simple, green and fast method for the preparation of multi-functional materials. In this study, inspired by the hierarchical ＂brick-and-mortar＂ structure and excellent mechanical performance of nacre, a fast green vacuum-filtration method was used to fabricate strong and multifunctional polyglutamic acid/layered double hydroxide （PGA/LDH） films mimicking nacre. The experimental results confirm that the artificial nacre has hierarchical ＂brick-and-mortar＂ structure. It exhibits excellent strength （93.5 MPa） and flexibility （easily bendable fold）, combining with outstanding properties of UV-blocking and translucence properties. This work provides a way of fabricating multifunctional organic-inorganic hybrid films, which has potential applications in the areas of optical, transportation and construction fields.展开更多
Despite lignin nanoparticles (LNPs) being extensively employed as assistant agents to improve the UV-blocking performance of sunscreens, there is a lack of information addressing how and to what extent the chemical an...Despite lignin nanoparticles (LNPs) being extensively employed as assistant agents to improve the UV-blocking performance of sunscreens, there is a lack of information addressing how and to what extent the chemical and structural features of these particles relate to the improvements observed in the Sun Protection Factors (SPF) of the sunscreens. In this study, lignin oligomers were prepared by a solvothermal extraction process of five typical biomasses in a water–acetone co-solvent without noticeable degradation of the cellulose fraction. Afterward, LNPs were produced from the self-assembly of these lignin oligomers via the solvent-shifting methodology. When incorporated into the sunscreen, these had different morphologies, and exerted different UV-blocking capacities. The effects of the chemical structure and size distribution of the LNPs were systematically studied and compared to those of the original lignin oligomers. LNPs exhibited better UV-blocking ability than soluble lignin oligomers due to the more exposed chromophore on the surface. Besides, compact LNPs with conjugating Cdouble bondO and β-O-4 linkages, as well as the presence of the syringyl unit rich in the methoxyl group in the structures, were beneficial in boosting the UV resistance of the sunscreens. Even though smaller LNPs with higher surface area favored the UV shielding performance, LNPs with widely distributed sizes could further help decrease the UV transmittance. These findings provide an excellent basis for using lignin-derived materials as sunscreen additives and pave the way to developing new environmentally friendly materials for the cosmetic industry.展开更多
基金supported by the National Basic Research Program of China(No.2010CB934700)
文摘Due to the various needs in the current applications, multifunctional composite materials with high strength and high toughness were highly desired now. Many scholars dedicated their time to find a simple, green and fast method for the preparation of multi-functional materials. In this study, inspired by the hierarchical ＂brick-and-mortar＂ structure and excellent mechanical performance of nacre, a fast green vacuum-filtration method was used to fabricate strong and multifunctional polyglutamic acid/layered double hydroxide （PGA/LDH） films mimicking nacre. The experimental results confirm that the artificial nacre has hierarchical ＂brick-and-mortar＂ structure. It exhibits excellent strength （93.5 MPa） and flexibility （easily bendable fold）, combining with outstanding properties of UV-blocking and translucence properties. This work provides a way of fabricating multifunctional organic-inorganic hybrid films, which has potential applications in the areas of optical, transportation and construction fields.
基金supported by the National Natural Science Foundation of China(22078211).
文摘Despite lignin nanoparticles (LNPs) being extensively employed as assistant agents to improve the UV-blocking performance of sunscreens, there is a lack of information addressing how and to what extent the chemical and structural features of these particles relate to the improvements observed in the Sun Protection Factors (SPF) of the sunscreens. In this study, lignin oligomers were prepared by a solvothermal extraction process of five typical biomasses in a water–acetone co-solvent without noticeable degradation of the cellulose fraction. Afterward, LNPs were produced from the self-assembly of these lignin oligomers via the solvent-shifting methodology. When incorporated into the sunscreen, these had different morphologies, and exerted different UV-blocking capacities. The effects of the chemical structure and size distribution of the LNPs were systematically studied and compared to those of the original lignin oligomers. LNPs exhibited better UV-blocking ability than soluble lignin oligomers due to the more exposed chromophore on the surface. Besides, compact LNPs with conjugating Cdouble bondO and β-O-4 linkages, as well as the presence of the syringyl unit rich in the methoxyl group in the structures, were beneficial in boosting the UV resistance of the sunscreens. Even though smaller LNPs with higher surface area favored the UV shielding performance, LNPs with widely distributed sizes could further help decrease the UV transmittance. These findings provide an excellent basis for using lignin-derived materials as sunscreen additives and pave the way to developing new environmentally friendly materials for the cosmetic industry.
