Multi-branch strategy to decorate carboxyl groups on cellulose nanocrystals to prepare adsorbent/flocculants and Pickering emulsions
writer：Mei-Li Song, Hou-Yong Yu, Lu-Min Chen, Jiaying Zhu, Yan- Yan Wang, Juming Yao, Zhuanyong Zou, and Ka
keywords：Cellulose nanocrystals, Multi-branch, Carboxyl content, Adsorption performance, Flocculation performance
source：期刊
Issue time：2019年
A simple multi-branch strategy was employed to increase the carboxyl contents
on CNC surface. The effects of various sequential grafting of ascorbic acid or citric acid on
the morphology, microstructure, thermal stability, dye adsorption capability (methylene blue)
and coagulation–flocculation capacity (model Kaolin suspension) of the functionalized CNCs
were investigated. Cellulose nanocrystals with multi-carboxyl groups (CNC-g-AA-g-CA)
showed better thermal stability (Tmax=359.3oC), and possessed the highest carboxylic groups
of 4.073mmol/g, which led to a high absolute zeta potential value up to 47.7 mV.
Furthermore, the CNC-g-AA-g-CA exhibited excellent coagulation?flocculation capability to
kaolin suspension with a turbidity removal rate of 91.07% and good cationic dye (methylene
blue) removal rate of 87.8%, indicating that the CNC-g-AA-g-CA can be used as excellent
adsorbent and efficient flocculants. Besides, CNC-g-AA-g-CA have good stabilizing effects
on soybean oil/water Pickering emulsions and the resultant Pickering emulsion volume can
remain for 30 days or longer.