Synthesis and conservation of cellulose nanocrystals

• Published in: Carbohydrate polymers 2020-06, Vol.238, p.116187-116187, Article 116187
• Main Authors: Di Giorgio, Luciana, Martín, Lucía, Salgado, Pablo R., Mauri, Adriana N.
• Format: Article
• Language: English
• Subjects: Cellulose nanocrystals; Conservation; Drying; Re-dispersion in water; Synthesis
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2020.116187

[Display omitted] •CNC dispersion remained stable for at least 2 years in refrigerated storage.•CNC characteristics were affected during drying depending on the process.•Drying favour CNC aggregation hindering their re dispersion in water.•Drying technique affects powder morphology and the possibility of CNC redispersion.•Lyophilized CNC were redispersed after US treatments at certain concentration. This work deals with the preparation of cellulose nanocrystals (CNC) from microcrystalline cellulose by acid hydrolysis, discusses how their characteristics varied according to the drying technique used for their conservation and analyzes their re-dispersion in water. A stable water dispersion of “rod” or “needle” type CNC (≈5 nm of diameter, 276 nm of length and 41 mV of Z potencial) was initially prepared and then dried by lyophilization and spray. Thus powders with similar cristalinity but different morphology were obtained, while CNC seemed to aggregate in such an extent that hindered their re-dispersion in water. Only lyophilized CNC could be re-dispersed in water and maintained stable in dispersion for at least 24 h, when working with concentrations of CNC higher than a certain minimum value (3 %) and after submitting them to intense ultrasound treatments. The tested time achieved should be enough to allow their subsequent use in several applications.