Lignocellulosic nanofibrils (LCNFs) isolation is recognized as an efficient strategy for maximizing biomass utilization. Nevertheless, achieving a 100% yield presents a formidable challenge. Here, an esterification strategy mediated by the equilibrium moisture in biomass is proposed for LCNFs preparation without the use of catalysts, resulting in a yield exceeding 100%. Different from anhydrous chemical thermomechanical pulp (CTMP0%), the presence of moisture (moisture content of 7 wt%, denoted as CTMP7%) introduces a notably distinct process for the pretreatment of CTMP, comprising the initial disintegration and the post‐esterification steps. The maleic acid, generated through maleic anhydride (MA) hydrolysis, degrades the recalcitrant lignin‐carbohydrate complex (LCC) structures, resulting in esterified CTMP7% (E‐CTMP7%). The highly grafted esters compensate for the mass loss resulting from the partial removal of hydrolyzed lignin and hemicellulose, ensuring a high yield. Following microfluidization, favorable LCNF7% with a high yield (114.4 ± 3.0%) and a high charge content (1.74 ± 0.09 mmol g−1) can be easily produced, surpassing most previous records for LCNFs. Additionally, LCNF7% presented highly processability for filaments, films, and 3D honeycomb structures preparation. These findings provide valuable insights and guidance for achieving a high yield in the isolation of LCNFs from biomass through the mediation of equilibrium moisture.

中文翻译：

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平衡水分介导的酯化反应实现超过 100% 的木质纤维素纳米原纤维产率


木质纤维素纳米原纤维（LCNF）分离被认为是最大化生物质利用的有效策略。然而，实现 100% 的良率仍是一项艰巨的挑战。在此，提出了一种由生物质平衡水分介导的酯化策略，用于在不使用催化剂的情况下制备 LCNF，产率超过 100%。与无水化学热机械浆（CTMP0%）不同，水分的存在（水分含量为 7 wt%，表示为 CTMP7%）为 CTMP 的预处理引入了一个明显不同的过程，包括初始崩解和后酯化步骤。通过马来酸酐 (MA) 水解产生的马来酸会降解顽固的木质素-碳水化合物复合物 (LCC) 结构，产生酯化的 CTMP7% (E-CTMP7%)。高度接枝的酯补偿了因部分去除水解木质素和半纤维素而造成的质量损失，确保了高产率。微流化后，可以轻松生产出具有高产率（114.4 ± 3.0%）和高电荷含量（1.74 ± 0.09 mmol g−1）的有利 LCNF7%，超过了 LCNF 的大多数先前记录。此外，LCNF7% 对于长丝、薄膜和 3D 蜂窝结构制备具有高度的加工性能。这些发现为通过平衡水分的调节从生物质中分离 LCNF 实现高产率提供了宝贵的见解和指导。