Adamcyk Johannes, Beisl Stefan, Amini Samaneh, Jung Thomas, Zikeli Florian, Labidi Jalel, Friedl Anton
Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, 1060 Vienna, Austria.
Chemical and Environmental Engineering Department, University of the Basque Country UPV/EHU, 20018 Donostia-San Sebastián, Spain.
Polymers (Basel). 2021 Jan 26;13(3):384. doi: 10.3390/polym13030384.
Despite major efforts in recent years, lignin as an abundant biopolymer is still underutilized in material applications. The production of lignin nanoparticles with improved properties through a high specific surface area enables easier applicability and higher value applications. Current precipitation processes often show poor yields, as a portion of the lignin stays in solution. In the present work, lignin was extracted from wheat straw, spruce, and beech using ethanol organosolv pretreatment at temperatures from 160-220 °C. The resulting extracts were standardized to the lowest lignin content and precipitated by solvent-shifting to produce lignin micro- and nanoparticles with mean hydrodynamic diameters from 67.8 to 1156.4 nm. Extracts, particles and supernatant were analyzed on molecular weight, revealing that large lignin molecules are precipitated while small lignin molecules stay in solution. The particles were purified by dialysis and characterized on their color and antioxidant activity, reaching ASC equivalents between 19.1 and 50.4 mg/mg. This work gives detailed insight into the precipitation process with respect to different raw materials and pretreatment severities, enabling better understanding and optimization of lignin nanoparticle precipitation.
尽管近年来付出了巨大努力，但木质素作为一种丰富的生物聚合物在材料应用中仍未得到充分利用。通过高比表面积生产具有改进性能的木质素纳米颗粒能够使其更易于应用并实现更高价值的应用。目前的沉淀过程往往产率较低，因为一部分木质素会留在溶液中。在本工作中，使用乙醇有机溶剂预处理在160 - 220°C的温度下从麦秸、云杉和山毛榉中提取木质素。将所得提取物标准化至最低木质素含量，并通过溶剂转移沉淀以制备平均流体动力学直径为67.8至1156.4 nm的木质素微米和纳米颗粒。对提取物、颗粒和上清液进行分子量分析，结果表明大的木质素分子会沉淀，而小的木质素分子则留在溶液中。通过透析对颗粒进行纯化，并对其颜色和抗氧化活性进行表征，达到的抗坏血酸当量在19.1至50.4 mg/mg之间。这项工作详细深入地研究了针对不同原材料和预处理强度的沉淀过程，有助于更好地理解和优化木质素纳米颗粒的沉淀。
