title: Ultrasonication-assisted manufacture of cellulose nanocrystals esterified with acetic acid.
abstract: 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 40 kHz, 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 100 nm. The study provides a simple and convenient method to manufacture E-CNCs.
authors.affiliation: Fujian Agriculture and Forestry University, Fuzhou 350002, China.
authors.forename: Lirong
authors.initials: L
authors.lastname: Tang
authors.forename: Biao
authors.initials: B
authors.lastname: Huang
authors.forename: Qilin
authors.initials: Q
authors.lastname: Lu
authors.forename: Siqun
authors.initials: S
authors.lastname: Wang
authors.forename: Wen
authors.initials: W
authors.lastname: Ou
authors.forename: Wenyi
authors.initials: W
authors.lastname: Lin
authors.forename: Xuerong
authors.initials: X
authors.lastname: Chen
mesh_terms: D019342:Acetic Acid / Q000737:chemistry*; D002247:Carbon Isotopes / Q000032:analysis; D002482:Cellulose / Q000737:chemistry*; D004951:Esterification; D009682:Magnetic Resonance Spectroscopy; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D017550:Spectroscopy, Fourier Transform Infrared; D014465:Ultrasonics / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D002247:Carbon Isotopes; D002482:Cellulose; D019342:Acetic Acid