Protonation behavior of cotton fabric with irreversibly adsorbed chitosan: A potentiometric titration study

Duško Čakara, Lidija Fras Zemljič, Matej Bračič, Karin Stana Kleinschek

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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 languageEnglish
Pages (from-to)36-40
Number of pages5
JournalCarbohydrate Polymers
Issue number1
Publication statusPublished - 4 Aug 2009
Externally publishedYes



  • Adsorption
  • Antimicrobial
  • Charge
  • Chitosan
  • Cotton
  • Medical
  • pH
  • pK
  • Potentiometric
  • Protonation
  • Titration

ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Materials Chemistry

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