Publication detail

The Influence of Counterions of Different Valency on Carboxymethylcellulose Viscoelastic Behavior

CHYTIL, M. JANEČEK, J. LIŠKOVÁ, K.

Original Title

Type

book chapter

Language

English

Original Abstract

This chapter focuses on an investigation of various counterions effect on viscoleastic behavior of sodium carboxymethylcellulose (Na-CMC) in aqueous solutions. Besides, the influence of the polymer concentration is also discussed. The concentration series of Na-CMC aqueous solutions with the presence of Na+, Ca2+ and Al3+ ions in different molar ratios to the polymer were investigated by means of oscillatory measurements. The viscoelastic properties were discussed particularly in terms of the complex modulus (G*) and the loss angle (delta). Two opposite effects were observed; a slight reinforcement of the elasticity and the overall mechanical resistance as the concentration of the Na-CMC increased on one side, and a profound decrease in delta, in the presence of Ca2+ counterions even at low CMC concentrations on the other. The former phenomenon is attributed to mainly polymer chains mutual interactions and their entanglements, while the latter is assumed to be due to intramolecular crosslinking of the polymer carboxyl groups with bivalent Ca2+ ions. The crucial factor for switching from one phenomenon to another is the molar ratio between Ca2+ ions and caboxyl groups, which begins at the ratio higher than approximately 1:1.6. The effect of Al3+ ions was observed to be even more remarkable.

Keywords

counterions, viscoelasticity, carboxymethylcelulose, rheology, oscillation, gelation

Authors

CHYTIL, M.; JANEČEK, J.; LIŠKOVÁ, K.

RIV year

2014

Released

1. 1. 2014

Publisher

Nova Science Publishers, Inc.

Location

New York

ISBN

978-1-62618-999-7

Book

Rheology: theory, properties, and practical applications

Edition

Physics Research and Technology

Edition number

Pages from

349

Pages to

357

Pages count

BibTex

@inbook{BUT104288,
  author="CHYTIL, M. and JANEČEK, J. and LIŠKOVÁ, K.",
  title="The Influence of Counterions of Different Valency on Carboxymethylcellulose Viscoelastic Behavior",
  booktitle="Rheology: theory, properties, and practical applications",
  year="2014",
  publisher="Nova Science Publishers, Inc.",
  address="New York",
  series="Physics Research and Technology",
  edition="1",
  pages="349--357",
  isbn="978-1-62618-999-7"
}