Abstract:
In recent years, concerns about the harmful effects of synthetic UV filters on the environment have highlighted the need for natural sun blockers. Lignin, the most abundant aromatic renewable biopolymer on Earth, is a promising candidate for next-generation sunscreen due to its inherent UV absorbance and its green, biodegradable, and biocompatible properties. Lignin\'s limitations, such as its dark color and poor dispersity, can be overcome by reducing particle size to the nanoscale, enhancing UV protection and formulation. In this study, 100-200 nm lignin nanoparticles (LNPs) were prepared from various biomass by-products (hardwood, softwood, and herbaceous material) using an eco-friendly anti-solvent precipitation method. Pure lignin macroparticles (LMPs) were extracted from beech, spruce, and wheat straw using an ethanol-organosolv treatment and compared with sulfur-rich kraft lignin (KL). Sunscreen lotions made from these LMPs and LNPs at various concentrations demonstrated novel UV-shielding properties based on biomass source and particle size. The results showed that transitioning from the macro- to nanoscale increased the sun protection factor (SPF) by at least 2.5 times, with the best results improving the SPF from 7.5 to 42 for wheat straw LMPs and LNPs at 5 wt%. This study underscores lignin\'s potential in developing high-quality green sunscreens, aligning with green chemistry principles.
摘要:
近年来,对合成紫外线过滤剂对环境的有害影响的担忧突出了对天然防晒剂的需求。木质素,地球上最丰富的芳香族可再生生物聚合物,由于其固有的紫外线吸收和绿色,是下一代防晒霜的有希望的候选产品,可生物降解,和生物相容性。木质素的限制,比如它的深色和分散性差,可以通过将颗粒尺寸减小到纳米级来克服,增强紫外线保护和配方。在这项研究中,100-200nm木质素纳米颗粒(LNPs)由各种生物质副产品(硬木,软木,和草本材料)使用环保的反溶剂沉淀法。纯木质素大颗粒(LMPs)从山毛榉提取,云杉,和小麦秸秆使用乙醇-有机溶剂处理,并与富含硫的硫酸盐木质素(KL)进行了比较。由这些LMP和LNP以各种浓度制成的防晒乳液显示出基于生物质来源和粒度的新型UV屏蔽特性。结果表明,从宏观到纳米尺度的过渡将防晒系数(SPF)提高了至少2.5倍,以5wt%的小麦秸秆LMPs和LNP的SPF从7.5提高到42,结果最好。这项研究强调了木质素在开发高质量绿色防晒霜方面的潜力,符合绿色化学原则。