Water activity of aqueous solutions of ethylene oxide-propylene oxide block copolymers and maltodextrins

AUTOR(ES)

Carareto, N. D. D., Monteiro Filho, E. S., Pessôa Filho, P. A., Meirelles, A. J. A.

FONTE

Brazilian Journal of Chemical Engineering

DATA DE PUBLICAÇÃO

2010-03

RESUMO

The water activity of aqueous solutions of EO-PO block copolymers of six different molar masses and EO/PO ratios and of maltodextrins of three different molar masses was determined at 298.15 K. The results showed that these aqueous solutions present a negative deviation from Raoult's law. The Flory-Huggins and UNIFAC excess Gibbs energy models were employed to model the experimental data. While a good agreement was obtained with the Flory-Huggins equation, discrepancies were observed when predicting the experimental behavior with the UNIFAC model. The water activities of ternary systems formed by a synthetic polymer, maltodextrin and water were also measured and used to test the predictive capability of both models.

Documentos Relacionados

• The effects of ethylene oxide containing lipopolymers and tri-block copolymers on lipid bilayers of dipalmitoylphosphatidylcholine.
• Binary Micellar Solutions of Poly(Ethylene Oxide)-Poly(Styrene Oxide) Copolymers with Pluronic® P123: Drug Solubilisation and Cytotoxicity Studies
• Microbiological Aspects of Ethylene Oxide Sterilization: III. Effects of Humidity and Water Activity on the Sporicidal Activity of Ethylene Oxide
• Effect of the structure of commercial poly(ethylene oxide-b-propylene oxide) demulsifier bases on the demulsification of water-in-crude oil emulsions: elucidation of the demulsification mechanism
• Formation of cage-like particles by poly(amino acid)-based block copolymers in aqueous solution.