skip to main content
Language:
Search Limited to: Search Limited to: Resource type Show Results with: Show Results with: Search type Index

General procedure for determining cellulose nanocrystal sulfate half-ester content by conductometric titration

Cellulose (London), 2015-02, Vol.22 (1), p.101-116 [Peer Reviewed Journal]

Springer Science+Business Media Dordrecht 2014 ;Cellulose is a copyright of Springer, (2014). All Rights Reserved. ;ISSN: 0969-0239 ;EISSN: 1572-882X ;DOI: 10.1007/s10570-014-0513-y

Full text available

Citations Cited by
  • Title:
    General procedure for determining cellulose nanocrystal sulfate half-ester content by conductometric titration
  • Author: Beck, Stephanie ; Méthot, Myriam ; Bouchard, Jean
  • Subjects: acid hydrolysis ; Bioorganic Chemistry ; Cellulose ; Cellulose esters ; Ceramics ; Chemistry ; Chemistry and Materials Science ; Composites ; Control stability ; crystal structure ; Esters ; feedstocks ; Glass ; instrumentation ; Liquid crystals ; Nanocrystals ; Natural Materials ; neutralization ; Optical properties ; Organic Chemistry ; Original Paper ; Physical Chemistry ; Polymer Sciences ; Protonation ; Rheological properties ; Sodium hydroxide ; Sulfur ; Sulfur content ; Sulfuric acid ; Surface charge ; Sustainable Development ; Titration ; Wood pulp
  • Is Part Of: Cellulose (London), 2015-02, Vol.22 (1), p.101-116
  • Description: Charged groups on the surface of cellulose nanocrystals (CNCs) control the colloidal stability and electrostatic and rheological properties of aqueous CNC suspensions, as well as their ability to self-assemble into liquid crystalline structures with unique optical properties. CNCs extracted from wood pulp by sulfuric acid hydrolysis typically contain 200–300 mmol/kg of anionic sulfate half-esters introduced at some of the hydroxyl sites. Two analysis methods to determine CNC surface charge are presented in the published literature: total sulfur content determination by elemental analysis and protonated sulfate half-ester group determination by conductometric titration with sodium hydroxide. The main drawbacks to elemental analysis are the expensive and complicated instrumentation and sample preparation procedures it requires. Conductometric titration is a much simpler method, but requires complete protonation of the CNC samples in order to obtain an accurate value. Unfortunately, significant discrepancies between the sulfate half-ester contents measured with the two techniques are often observed in the literature, particularly with neutralized Na-CNCs. There are specific assumptions and pitfalls inherent to both analysis methods which must be taken into account and reconciled if comparable results are to be achieved by titration and elemental analysis. In particular, sample preparation is crucial to obtaining accurate determinations of sulfate half-ester content by conductometric titration; however, methods differ widely among laboratories and are often not specified in detail, rendering published results meaningless. We have developed a rapid sample preparation protocol which allows quantitative and accurate determination of the sulfate half-ester content of CNCs from various cellulosic feedstocks (for H- and Na-CNCs, in both never-dried and redispersed dried forms) by conductometric titration, yielding results in good agreement with the total sulfur content determined by elemental analysis.
  • Publisher: Dordrecht: Springer-Verlag
  • Language: English
  • Identifier: ISSN: 0969-0239
    EISSN: 1572-882X
    DOI: 10.1007/s10570-014-0513-y
  • Source: ProQuest Central
Back to results list
INSPIRE LIBRARY - TON DUC THANG UNIVERSITY (84-028) 37 755 057 Feedback
19 Nguyen Huu Tho St. Dist.7, HCM thuvien@tdtu.edu.vn

Copyright © 2017 INSPIRE LIBRARY - TON DUC THANG UNIVERSITY

Searching Remote Databases, Please Wait