Abstract
The protonation of cotton fabric with irreversibly adsorbed medical chitosan (CO-CT) was measured in aquatic medium at 0.1 M ionic strength by means of potentiometric titrations, and compared with the results obtained for pure cotton and chitosan. For CO-CT, the charging isotherm exhibits a charge reversal around pH ≈ 6.0, which is identified as the point of zero charge (PZC). The pure chitosan and the acid fraction that is present in cotton, protonate according to the one-pK model, with p KCT = 6.3 and p KCO = 4.7, respectively. At pH > PZC, the charge of the acid fraction in CO-CT is negative and constant, and the proton binding is attributed purely to the adsorbed chitosan. On the other hand, the cotton-bound acid exhibits a more complex protonation mechanism in CO-CT than in the pure fabric, which is evidenced as an excess positive charge at pH < PZC and a deviation from the one-pK behavior.
Original language | English |
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Pages (from-to) | 36-40 |
Number of pages | 5 |
Journal | Carbohydrate Polymers |
Volume | 78 |
Issue number | 1 |
DOIs | |
Publication status | Published - 4 Aug 2009 |
Externally published | Yes |
Keywords
- Adsorption
- Antimicrobial
- Charge
- Chitosan
- Cotton
- Medical
- pH
- pK
- Potentiometric
- Protonation
- Titration
ASJC Scopus subject areas
- Organic Chemistry
- Polymers and Plastics
- Materials Chemistry