木质素纳米微球制备及其抗紫外应用基础研究

Lignin is the second most abundant component in plant and it mostly distributes in the cell wall part. Lignin not only locks water for plants, has antimicrobial activity, but also protects plants against UV irradiation. Lignin is renewable, biocompatible and thus is an excellent natural macromolecular UV-blocker. However, the deep color, random aggregation and poor compatibility with other materials have seriously hindered the application of industrial lignin in areas such as sunscreens and UV-blocking functional materials. In this project, uniform lignin colloidal spheres are prepared by chemical modifying and self-assembling. Formation of nano spheres makes lignin aggregate orderly and effectively lightens the deep color. Through further optimization of self-assembling, the antioxidant property of lignin could be reserved, and the reaction-free lignin nano spheres with different amphiphilic surfaces could be prepared, which will not only improve the material’s compatibilty, but also enhance the UV-blocking performance. Based on this, the transforming condition and mechanism for the formation of lignin nano spheres will be studied, providing the theoretical basis and technical instruction for the preparation of ordered lignin-based nano materials. Furthermore, lignin/chemical sunscreen nano capsules are prepared by ultrasonic irradiation to improve the sunscreen performance. The synergistic effect between lignin and chemical sunscreens are systematically investigated. The implement of this project will open up high-end applications for lignin in areas such as ordered nano materials and UV-blocking sunscreens and composites.

木质素是植物中第二大组分，大量分布于植物细胞壁，起着锁水、抗菌、保护植物抵御紫外辐照等作用，可再生、生物相容性好，是理想的天然高分子抗紫外剂。但是，工业木质素存在颜色深、容易团聚、材料相容性差等问题，严重阻碍其在防晒护肤、功能材料等领域的应用。本项目拟通过改性自组装制备均一有序的改性木质素纳米微球，解决无规团聚、颜色深等问题，揭示木质素发色基团及其变化规律；进一步优化工艺，保留木质素优异的抗氧化性能，直接通过自组装制备表面亲疏水性不同的木质素纳米微球，提高抗紫外能力，解决材料相容性差等难题。在此基础上，探索纳米微球转变条件和转变机理，为规则木质素纳米材料的制备提供理论基础和技术指导。进一步将木质素与化学防晒剂复配，制备木质素/防晒剂复合纳米囊泡，提升抗紫外性能并研究木质素的防晒机理。本项目的实施将为木质素在纳米材料和紫外防护领域开辟新的空间，开启木质素在防晒护肤、功能材料等高端领域的应用。

木质素是植物中第二大组分，大量分布于植物细胞壁，起着锁水、抗菌、保护植物抵御紫外辐照等作用，可再生、生物相容性好，是理想的天然高分子抗紫外剂。本项目从松木直接提取或者工业木质素分离提纯，得到生物相容性良好的木质素，测定木质素的理化参数，调控木质素的分子间作用力与微结构；将提纯木质素浅色化改性，通过超分子自组装制备表面亲水的纳米微球、表面疏水的反相胶束以、木质素纳米胶囊、木质素/无机复合纳米颗粒；将木质素纳米微球、微胶囊、复合颗粒与空白乳霜共混制备防晒霜，添加10 wt%的紫外防晒指数（SPF）15-400可控，阳光辐照以后性能更好，可以保持高防晒性能8小时以上；将木质素胶体球、反相胶束与聚丙烯酸、聚烯烃共混制备功能涂层与塑料，不但抗紫外老化性能优异，而且赋予材料良好的强度与韧性。本项目的实施为木质素在纳米材料和紫外防护领域开辟新的空间，推动木质素在防晒护肤、功能材料等高端领域的应用。相关研究成果共发表研究论文15篇，其中SCI二区Top论文以上10篇，申请国家发明专利6项，PCT专利2项，获得授权发明专利5项；培养研究生4人。项目负责人2017年破格晋升为研究员，并获得广州市珠江科技新星项目，广东省杰出青年项目资助。