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US 12,320,069 B2Granted
Carboxylated cellulose nanofiber and preparation method thereof
AssigneeNortheast Forestry University
InventorsHaipeng Yu, Xiaochao Shi, Qinqin Xia
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Abstract
Disclosed herein is a carboxylated cellulose nanofiber and a preparation method thereof. The method includes: mixing choline chloride, citric acid and water at 60-100° C. for 15-60 min to obtain a hydrated multi-carboxylic acid deep eutectic solvent (H-DES); mixing the H-DES and cellulose for hydrolysis-esterification reaction at 120-130° C. for 2-3 h to obtain a carboxylated cellulose; and mixing the carboxylated cellulose and water for nano-fibrillation to obtain the carboxylated cellulose nanofiber.
Claims3
A method for preparing a carboxylated cellulose nanofiber, comprising:
- (1) mixing choline chloride, citric acid and water at 60-100° C. for 15-60 minutes to obtain a hydrated multi-carboxylic acid deep eutectic solvent;
- (2) mixing the hydrated multi-carboxylic acid deep eutectic solvent with cellulose followed by hydrolysis-esterification reaction at 120-130° C. for 2-3 hours to obtain a carboxylated cellulose;
- and
- (3) mixing the carboxylated cellulose and water followed by nano-fibrillation to obtain the carboxylated cellulose nanofiber;
- wherein in step (1), a ratio of a weight of the water to a total weight of the choline chloride and the citric acid is (0.25˜4):1;
- and a molar ratio of the choline chloride to the citric acid is 1:(1˜4);
- the carboxylated cellulose nanofiber has a carboxyl content of 0.23˜1.45 mmol/g, and an aspect ratio of 1000˜4000;
- and
- the nano-fibrillation is performed under an ultrasonic power of 600-1000 Watts for minutes min.
6 more elements
Dependencies are inferred from the claim text.