Lignin nanoparticles (LNPs) from lignocellulosic biomass are expected to become promising basic building blocks for various applications in the development of multifunctional nanocomposites. Facile green preparation of LNPs and their application in polyvinyl alcohol (PVA) composite films were studied in this paper. LNPs were produced by performing fractionation of wheat straws at less than 80 °C with a recyclable hydrotropic, aqueous p -toluene sulfonic acid ( p -TsOH). The dissolved lignin could be simply separated as LNPs by diluting the spent liquor (SL) to below the minimal hydrotropic concentration (MHC) of 11.5%. The resulting LPNs exhibited an oblate spheroid morphology and a uniform particle size distribution. After introducing the available LNPs into the PVA matrix at 6% loading, the nanocomposite products could block 100 and 95% of UV light at 315 and 400 nm, respectively, and exhibited 80% antioxidant activity. In addition, the respective maximum TS and TM were 59.7 MPa and 2.07 GPa, respectively, which were increases of approximately 36 and 104% compared with those of pure PVA film. The LNPs/PVA nanocomposite films displayed improved UV resistance, mechanical properties, thermal stability and antioxidant activity and could be used as additional multifunctional agents in the fields of biodegradable plastics, tissue engineering and UV-protective biobased materials.

中文翻译：

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水性溶液中木质素纳米粒子的绿色制备及其在生物基纳米复合薄膜中的应用

木质纤维素生物质的木质素纳米颗粒（LNP）有望成为有前途的基础构件，可用于开发多功能纳米复合材料的各种应用。研究了LNP的简便绿色制备及其在聚乙烯醇（PVA）复合膜中的应用。LNP是通过用可回收的水溶对甲苯磺酸水溶液（p -TsOH）在低于80°C的条件下对麦秸进行分馏而生产的。通过将废液（SL）稀释至低于11.5％的最低水溶浓度（MHC），可以将溶解的木质素简单地分离为LNP。所得的LPN显示出扁球形的球状形态和均匀的粒度分布。在以6％的负载量将可用的LNP引入PVA矩阵后，纳米复合产品可分别阻挡315和400 nm的100％和95％的紫外线，并表现出80％的抗氧化活性。此外，最大TS和TM分别为59.7 MPa和2.07 GPa，与纯PVA薄膜相比分别增加了约36％和104％。LNPs / PVA纳米复合材料薄膜具有改善的抗紫外线性，机械性能，热稳定性和抗氧化活性，可在生物可降解塑料，组织工程和具有紫外线保护作用的生物基材料领域用作附加的多功能剂。