Nanostructural characterization of the dehydrated (NIPA/SA + additive ion) gels

K. Hara, M. Sugiyama, M. Annaka, Y. Soejima

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


In the present study, the authors have investigated ion-absorption effects on a nanoscopic structure of a dehydrated N-isopropylacrylamide/sodium acrylate (NIPA/SA) gel. First of all, the authors compared small-angle X-ray scattering (SAXS) profile of a dehydrated NIPA/SA gel with that dehydrated after absorbing Cu 2+ ion. Then, in order to examine copper-ion distribution structure in the NIPA/SA gel dehydrated after absorption of copper-ion, an incident-X-ray energy-dependence of a small-angle X-ray scattering profile was observed, in which the anomalous dispersion effect was clearly perceived especially around a distinct SAXS-peak. Because the SAXS-peak is thought to come from a dehydration-induced microphase separation between hydrophilic and hydrophobic network-polymers in the NIPA/SA gel, such a feature indicates that the copper-ions gather in the dehydration-induced hydrophilic domains. In addition to this interesting copper-ion nanostructure in the dehydrated NIPA/SA gel, a difference in the SAXS-peak position between the dehydrated NIPA/SA gels with and without absorbing the copper-ion has shown a possibility of a controlling method of the nanostructure in relatively gentle conditions without special instruments. Along this line, in order to get further information on the ion-absorption effects on the nanostructure, the authors have compared the SAXS profiles of the several NIPA/SA gels which were dehydrated after absorbing respectively different kinds of ions. In the observation, the SAXS-peak positions have shown characteristic features which are different with the kind of the absorbed ions and found to be classified into several kinds according to the periodic-table group of the absorbed ion.

Original languageEnglish
Pages (from-to)197-200
Number of pages4
JournalColloids and Surfaces B: Biointerfaces
Issue number3-4 SPEC. ISS.
Publication statusPublished - Nov 15 2004

All Science Journal Classification (ASJC) codes

  • Biotechnology
  • Surfaces and Interfaces
  • Physical and Theoretical Chemistry
  • Colloid and Surface Chemistry


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