The Interaction Between N-Isopropylacrylamide-Acrylic Acid-Ethyl Methacrylate Thermosensitive Polymers and Cationic Surfactants

The interaction between cationic surfactants and isopropylacrylamide-acrylic acid-ethyl methacrylate (IPA:AA:EMA) terpolymers has been investigated using steady-state fluorescence and spectrophotometric measurements to assess the effect of the polymer composition on the aggregation process and terpo...

Full description

Saved in:
Bibliographic Details
Published in:Journal of dispersion science and technology 2009-09, Vol.30 (8), p.1121-1128
Main Authors: de Oliveira Tiera, Vera Aparecida, Tiera, Marcio José, Blaz Vieira, Neide Aparecida, do Amaral, Bruno Rochetti, Pires, Rogério Zambelli
Format: Article
Language:English
Subjects:
Cationic surfactants
Chemistry
Colloidal state and disperse state
Exact sciences and technology
fluorescence
General and physical chemistry
isopropylacrylamide
polyelectrolyte
thermosensitive
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The interaction between cationic surfactants and isopropylacrylamide-acrylic acid-ethyl methacrylate (IPA:AA:EMA) terpolymers has been investigated using steady-state fluorescence and spectrophotometric measurements to assess the effect of the polymer composition on the aggregation process and terpolymers' thermosensitivities. Micropolarity studies using pyrene show that the interaction of cationic surfactants with IPA:AA:EMA terpolymers occurs at surfactant concentrations much smaller than that observed for the pure surfactant in aqueous solution. The critical aggregation concentration (CAC) values decrease with both the hydrocarbon length of the surfactant and the content of ethyl methacrylate. These results were interpreted as a manifestation of the increasing contribution of attractive hydrophobic and electrostatic forces between negatively charged polymer chains and positively charged surfactant molecules. The increase of ethyl methacrylate in the copolymers lowers the CAC due to the larger hydrophobic character of the polymer backbone. The cloud point determination reveals that the lower critical solution temperatures (LCST) depend strongly on the copolymer composition and surfactant nature. The binding of surfactants molecules to the polymer chain screens the electrostatic repulsion between the carboxylic groups inducing a conformational transition and the dehydration of the polymer chain.
ISSN:0193-2691
1532-2351
DOI:10.1080/01932690802701499