Open AccessA COMPARATIVE STUDY OF CELLULOSE NANOWHISKERS (CNWs) AND CELLULOSE NANOFIBERS (CNFs)
Author(s) -
Zhijun Hu,
Xinyu Cao,
Daliang Guo,
Yinchao Xu,
Pengfei Wu,
Peter Christie,
Jing Li
Publication year - 2021
Publication title -
cellulose chemistry and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.302
H-Index - 32
eISSN - 2457-9459
pISSN - 0576-9787
DOI - 10.35812/cellulosechemtechnol.2021.55.45
Subject(s) - crystallinity , cellulose , nanofiber , thermogravimetric analysis , raw material , supercritical fluid , scanning electron microscope , materials science , chemical engineering , composite material , thermal stability , chemistry , organic chemistry , engineering
Cellulose nanowhiskers (CNWs) from plant biomass are of considerable interest, primarily due to their low density, biodegradability, mechanical strength, economic output, and renewability. Here, a new pretreatment method has been developed to produce CNWs based on supercritical CO2 and ethanol. The raw material was micro-fibrillated cellulose (MFC) and experimental factors were controlled to enhance the properties of CNWs produced using a ball-milling technique following supercritical CO2 pretreatment. Cellulose nanofibers (CNFs) were also prepared using a high-pressure Microfluidizer©. A comparative study was conducted of the properties of the raw materials, the CNWs and the CNFs. The solid yields of P-MFC after supercritical CO2 pretreatment gradually decreased, along with the temperature and the reaction time. Scanning electron microscopy (SEM) images of the CNWs and CNFs show that the morphology of the CNWs was basically acicular, while that of the CNFs was mainly soft fibrous. Thermogravimetric analysis results suggest that the thermal stability of the CNWs was substantially higher than those of the CNFs and the raw material. XRD results indicate that the crystallinity showed an initial increasing trend and then declined with increasing temperature and reaction time, and the crystallinity value of CNWs was higher than that of CNFs. The smaller CNWs became rougher and had a larger surface area.