Department of Chemical and Materials Engineering, University of Dayton, 300 College Park, Dayton, OH 45469-0256, USA.
Materials Measurement Science Division, National Institute of Standards and Technology, 100 Bureau Dr., Gaithersburg, MD 20899, USA.
Int J Biol Macromol. 2021 Jun 30;181:313-321. doi: 10.1016/j.ijbiomac.2021.03.105. Epub 2021 Mar 22.
This work offers a facile fabrication method for lignin nanocomposites through the assembly of kraft lignin onto magnetic nanoparticles (FeO) based on pH-driven precipitation, without needing organic solvents or lignin functionalization. Kraft lignin@FeO multicore nanocomposites fabrication proceeded using a simple, pH-driven precipitation technique. An alkaline solution for kraft lignin (pH 12) was rapidly injected into an aqueous-based FeO nanoparticle colloidal suspension (pH 7) under constant mixing conditions, allowing the fabrication of lignin magnetic nanocomposites. The effects of increasing lignin to initial FeO mass content (g/g), increasing in ratio from 1:1 to 20:1, are discussed with a complete chemical, structural, and morphological characterization. Results showed that nanocomposites fabricated above 5:1 lignin:FeO had the highest lignin coverage and content (>20%), possessed superparamagnetic properties (Ms ≈ 45,000 A·m/kg); had a negative surface charge (-30 mV), and formed multicore nanostructures (D ≈ 150 nm). The multicore lignin@FeO nanocomposites allowed rapid magnetically induced separations from suspension. After 5 min exposure to a rare-earth neodymium magnet (1.27 mm × 1.27 mm × 5.08 mm), lignin@FeO nanocomposites exhibited a maximum methylene blue removal efficiency of 74.1% ± 7.1%. These nanocomposites have potential in magnetically induced separations to remove organic dyes, heavy metals, or other lignin adsorbates.
这项工作提供了一种通过 kraft 木质素基于 pH 驱动沉淀组装到磁性纳米颗粒 (FeO) 上来制备木质素纳米复合材料的简便方法，无需有机溶剂或木质素功能化。通过简单的 pH 驱动沉淀技术制备 kraft 木质素@FeO 多核纳米复合材料。将 kraft 木质素的碱性溶液（pH 12）在恒速搅拌条件下快速注入到基于水的 FeO 纳米颗粒胶体悬浮液（pH 7）中，允许制备木质素磁性纳米复合材料。讨论了增加木质素与初始 FeO 质量含量（g/g）的影响，比例从 1:1 增加到 20:1。进行了全面的化学、结构和形态表征。结果表明，木质素：FeO 大于 5:1 制备的纳米复合材料具有最高的木质素覆盖率和含量（>20%），具有超顺磁性（Ms ≈ 45,000 A·m/kg）；具有负表面电荷（-30 mV），并形成多核纳米结构（D ≈ 150 nm）。多核木质素@FeO 纳米复合材料允许从悬浮液中快速进行磁诱导分离。在暴露于稀土钕磁铁（1.27 mm × 1.27 mm × 5.08 mm）5 分钟后，木质素@FeO 纳米复合材料表现出最大的亚甲基蓝去除效率为 74.1% ± 7.1%。这些纳米复合材料在磁诱导分离中去除有机染料、重金属或其他木质素吸附物方面具有潜力。
