Ultrasonication-assisted manufacture of cellulose nanocrystals esterified with acetic acid

• Published in: Bioresource technology 2013-01, Vol.127, p.100-105
• Main Authors: Tang, Lirong, Huang, Biao, Lu, Qilin, Wang, Siqun, Ou, Wen, Lin, Wenyi, Chen, Xuerong
• Format: Article
• Language: English
• Subjects: Acetic acid; Acetic Acid - chemistry; Biological and medical sciences; Carbon Isotopes - analysis; Cellulose; Cellulose - chemistry; Cellulose pulp; Characterization; Chemical industries; Derivatives; Esterification; Esterified cellulose nanocrystals; Fundamental and applied biological sciences. Psychology; Hydroxyl groups; Magnetic Resonance Spectroscopy; Manufacturing; Microscopy, Atomic Force; Microscopy, Electron, Transmission; Nanocrystals; Nanoparticles - chemistry; Nanotechnology - methods; pulp; Spectroscopy, Fourier Transform Infrared; sulfuric acid; temperature; ultrasonic treatment; Ultrasonication; Ultrasonics - methods; X-Ray Diffraction
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2012.09.133

► Cellulose degradation and esterification occurs simultaneously when ultrasonication is used in the reaction. ► Ultrasonication treatment plays an important role in the synchronous reaction. ► The effect of reaction conditions on yield and DS was investigated. ► A simple way to manufacture esterified cellulose nanocrystals is presented. Esterified cellulose nanocrystals (E-CNCs) are cellulose derivatives that could be applied in biomedical and chemical industries. E-CNCs were prepared with cellulose pulp using a mixture of 17.5M acetic and 18.4M sulfuric acid with the aid of ultrasonication. The effects of esterification time (3–7h), ultrasonication time (with a frequency of 40kHz, 0 to 6h) and temperature (68–75°C) on the yield and degree of substitution (DS) of E-CNCs were evaluated. The sample obtained without ultrasonication had the lowest yield and DS value of 48.16% and 0.22, respectively, whereas ultrasonication for 5h at 70°C resulted in a yield of 85.38% and a DS value of 0.46. Characterization indicated the successful esterification of hydroxyl groups of cellulose, and the width of rod-shaped E-CNCs was from 10 to 100nm. The study provides a simple and convenient method to manufacture E-CNCs.