Unusually Large Hysteresis of Temperature-Responsive Poly(N-ethyl-2- propionamidoacrylamide) Studied by Microcalorimetry and FT-IR

Mohamed R. Berber, Hironori Mori, Inas H. Hafez, Keiji Minagawa, Masami Tanaka, Takuro Niidome, Yoshiki Katayama, Atsushi Maruyama, Tomohiro Hirano, Yasushi Maeda, Takeshi Mori

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

We reported here the full characterization of the hysteresis of the phase transition behavior of an aqueous solution of poly(N-ethyl-2- propionamidoacrylamide) (PNEPA), which has a unique α,α- disubstituted structure, by using microcalorimetry and FT-IR. Phase transition temperatures near the thermodynamic equilibrium were determined by extrapolating the scanning rate of the microcalorimetry to zero. The calculated hysteresis from the phase transition temperature was unusually very large (∼8 °C). FT-IR analysis indicated that the large hysteresis of PNEPA resulted from a coupling of intra-/intermonomeric unit hydrogen bonds, which is known to occur in a Β-sheet of proteins but has never been reported in temperature-responsive polymers. The effects of the molecular weight and polymer concentration on the hysteresis were studied by using fractionated PNEPAs and it was found that a low molecular weight and a low concentration enhanced the hysteresis.

Original languageEnglish
Pages (from-to)7784-7790
Number of pages7
JournalJournal of Physical Chemistry B
Volume114
Issue number23
DOIs
Publication statusPublished - Jun 17 2010

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Unusually Large Hysteresis of Temperature-Responsive Poly(N-ethyl-2- propionamidoacrylamide) Studied by Microcalorimetry and FT-IR'. Together they form a unique fingerprint.

  • Cite this