Diffusion of Molecular Probes in Thermoresponsive Poly(N-isopropylacrylamide) Hydrogels: Electroanalytical Studies

Abstract

Poly(N-isopropylacrylamide), NIPA, thermoresponsive hydrogels with well defined concentrations of an electroactive probe, 1,1'-ferrocenedimethanol, Fc(MeOH)2, were prepared. The discontinuous reversible volume phase transition of such gels occurs at 32 +/- deg C, and results in a release of approximately 93% of the solvent from the polymeric network. Transport of Fc(MeOH)2 in both swollen and collapsed gels was studied using steady state voltammetry and chronoamperometry at platinum microelectrodes. The diffusion coefficient of Fc(MeOH)2 in collapsed gels was approximately two orders of magnitude smaller than that in swollen gels. UV/vis spectroscopic studies shown that for a 3.0% NIPA gel the concentration of Fc(MeOH)2 in collapsed gel phase was approximately 6 time higher than that in released solution and 4.5 times higher than in the original swollen gel.

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Document Details

Document Type
Technical Report
Publication Date
Jul 15, 2001
Accession Number
ADA392376

Entities

People

  • I. Gaberman
  • M. Ciszkowska
  • Wei Zhang

Organizations

  • Brooklyn College

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Abstracts
  • Analytical Chemistry
  • Aqueous Solutions
  • Chemical Synthesis
  • Chemistry
  • Coefficients
  • Diffusion
  • Diffusion Coefficient
  • Electrodes
  • Gels
  • Hydrogels
  • Liquid Chromatography
  • Measurement
  • Perchlorates
  • Phase Transformations
  • Steady State
  • Transport Properties

Readers

  • Electrochemical Surface Science
  • Mathematics or Statistics
  • Polymer Science and Engineering.