Facile Extraction of Cellulose Nanofibrils (Cnfs) from Wood Using Acidic Ionic Liquid-catalyzed Organosolv Pretreatment Followed by Ultrasonic Processing

ABSTRACT

Cellulose nanofibrils (CNFs) were successfully extracted from wood flour via atwo-step process involving acidic ionic liquid-catalyzed organosolv pretreatment and ultrasonic disintegration. Acomprehensive study was performed on the yield, morphology, crystallinity, chemical structure, and thermal stability of CNFs, as well as the mechanical properties and transparency of nanofilms. The results showed that 87.06% of the total lignin and 93.78% of hemicellulose were fractionated from lignocellulose after solvothermal pretreatment using 1, 4-butylene glycol. The isolated CNF maintained the type Icrystal lattice of native cellulose. Overall, the CNFs obtained after ultrasonication displayed asimilar morphology and crystallinity, but they had ahigher yield (41.82%), better thermal stability, and film-forming properties than those produced by concentrated acid hydrolysis. Solvothermal treatment using 1,4-butylene glycol alcohol/water followed by ultrasonication is an ideal alternative CNF production method with alow environmental impact.

摘要

采用酸性离子液体催化有机溶剂预处理和超声崩解两步法从木粉中提取纤维素纳米纤维. 对CNFs的产率、形貌、结晶度、化学结构、热稳定性以及纳米薄膜的力学性能和透明性进行了综合研究. 结果表明，经1，4-丁二醇溶剂热预处理后，木质纤维素中总木质素和半纤维素的分离率分别为87.06%和93.78%. 分离的CNF保持了天然纤维素的Ι型晶格. 总的来说，超声处理后得到的CNFs具有相似的形貌和结晶度，但其产率（41.82%）、热稳定性和成膜性能均优于浓酸水解法. 采用1,4-丁二醇醇/水溶剂热处理，然后进行超声波处理是一种理想的替代CNF生产方法，对环境影响较小.

KEYWORDS:

• Cellulose nanofibril
• organosolv pretreatment
• acidic ionic liquid
• thermal stability
• delignification
• nanofilm

关键词:;:

• 纤维素纳米纤维
• 有机溶剂预处理
• 酸性离子液体
• 热稳定性
• 脱木素
• 纳米薄膜

Acknowledgments

This project was supported by the Fundamental Research Funds for the Central Universities (2572020DR13), and the National Natural Science Foundation of China (31470581)

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [31470581]; the Fundamental Research Funds for the Central universities [2572020DR13].