Facile one-pot fabrication of cellulose nanocrystals and enzymatic synthesis of its esterified derivative in mixed ionic liquids. Issue 43 (22nd May 2017)

• Record Type: Journal Article
• Authors: Zhao, Guanglei; Wang, Fengli; Lang, Xiongfei; He, Beihai; Li, Junrong; Li, Xiaofeng
• Is Part Of: RSC advances. Volume 7:Issue 43(2017)
• Page Start: 27017
• Page End: 27023
• Publication Date: 2017-05-22
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c7ra02570j
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : As an important cellulose derivative, esterified cellulose nanocrystals (E-CNCs) could be applied in biomedical and chemical industries. Abstract : As an important cellulose derivative, esterified cellulose nanocrystals (E-CNCs) could be applied in biomedical and chemical industries. A facile one-pot enzymatic method was proposed for the preparation of esterified cellulose nanocrystals with methyl laurate by using native cellulose as raw material in a binary ionic liquid (IL) system. 1-Butyl-3-methylimidazolium hydrogen sulfate ([BMIm]HSO4 ), a hydrophilic IL, acted as catalyst and solvent to produce cellulose nanocrystals (CNCs). 1-Butyl-3-methyl-imidazolium tetrafluoroborate ([BMIm][BF4 ]), which is hydrophobic, was used as a solvent for improving the lipase performance. The key reaction conditions, including mass ratio of [BMIm]HSO4 /[BMIm][BF4 ], molar ratio of methyl laurate/anhydroglucose unit (AGU) in cellulose, mass ratio of lipase/cellulose, and reaction time, showed significant influences on the enzymatic transesterification of CNCs. The ester products were confirmed by FT-IR and 13 C NMR analysis. The crystalline structure of E-CNCs was revealed by XRD. Compared with native cellulose, the E-CNCs showed improved crystallinity. TEM data showed the width of rod-shaped E-CNCs in the range of 10–30 nm. Compared to native cellulose, the thermal stability of E-CNCs was decreased due to the higher surface areas exposed to heat. This is the first successful preparation of E-CNCs with long-chain fatty acids from cheap native cellulose in a one-pot method.