University of Sfax, LMSE, Faculty of Science, BP 802, 3018 Sfax, Tunisia.
LEPAMAP-PRODIS Research Group, University of Girona, C/ Maria Aurèlia Capmany, 61, 17003 Girona, Spain.
Biomacromolecules. 2023 Aug 14;24(8):3872-3886. doi: 10.1021/acs.biomac.3c00515. Epub 2023 Jul 31.
Lignin-containing cellulose nanofibrils (LCNFs) have attracted great attention because the presence of lignin brought additional merits to cellulose nanofibrils including hydrophobicity, ultraviolet (UV)-shielding capacity, and reduced water sensitivity. In the present work, LCNFs with lignin content up to 21 wt % were prepared with a high yield exceeding 70 wt %, from neat date palm waste, by a hydrothermal treatment (HTT) at 120-150 °C in the presence of 20-30 wt % maleic acid, followed by high-pressure homogenization. The chemical composition, degree of polymerization, morphology, and colloidal and rheological properties of the LCNFs were investigated to understand how the HTT in the presence of MA affected the properties of the resulting LCNFs. Nanopapers prepared from the LCNF suspensions exhibited mechanical properties lower than those from lignin-free CNF-based nanopapers, yet with decreased hydrophilicity. A mechanism explaining how the HTT in the presence of MA facilitated the disintegration of the biomass into nanoscale material was proposed. Overall, the present work demonstrated a feasible and scalable approach for the sustainable production of LCNF suspensions from neat agricultural residues, with a high yield and a high lignin content, without any need to perform a preliminary partial delignification.
含木质素的纤维素纳米纤维（LCNF）因其具有疏水性、紫外线（UV）屏蔽能力和降低的水分敏感性等额外优点，而受到了广泛关注。在本工作中，以未处理的椰枣废弃物为原料，在 120-150°C 下，于 20-30wt%马来酸的存在下进行水热处理（HTT），然后进行高压匀浆，制备出木质素含量高达 21wt%、产率超过 70wt%的 LCNF。研究了 LCNF 的化学组成、聚合度、形态、胶体和流变性能，以了解 MA 存在下的 HTT 如何影响所得 LCNF 的性能。由 LCNF 悬浮液制备的纳米纸的机械性能低于无木质素的基于 CNF 的纳米纸，但亲水性降低。提出了一个解释 MA 存在下的 HTT 如何促进生物质分解为纳米级材料的机制。总的来说，本工作展示了一种从未处理的农业废弃物中可持续生产 LCNF 悬浮液的可行且可扩展的方法，具有高得率和高木质素含量，无需进行初步的部分脱木质素处理。
