Preparation of nano- and microparticles through self-assembly of azobenzene-pendent ionomers

Takeshi Mori, Keijiro Yuyama, Kanae Narita, Keiji Minagawa, Masanobu Haraguchi, Masami Tanaka

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


The particle formation of azobenzene-containing ionomers, through self-assembly, in aqueous media (THF/H2O solvent) was studied. The ionomers were synthesized by copolymerization between azobenzene-pendent methacrylate and methacrylic acid. It was revealed by UVvis spectra and light scattering measurements that the extent of H-aggregation of the azobenzene units first decreased, and then increased with increasing volume fraction of H 2O of the solvent. The H2O fraction at which the extent of H-aggregation began to increase became lower, when the copolymers contained more azobenzene units. Colloidal particles were prepared by slow addition of various concentrations of aqueous NaOH to the copolymer THF solutions. The hydrodynamic diameters of the particles obtained by the procedures were several hundreds of nanometer. When the azobenzene unit content in the copolymer was smaller, the diameters of the particles became smaller. When the colloidal particles dispersions were cast on a carbon sheet and dried, the particles aggregated and formed larger spherical particles, with diameters of several micrometers. The size of the particles obtained by the drying process became smaller, when higher concentrations of aqueous NaOH solutions were used. Therefore, the particle sizes were controlled by the azobenzene units content in the copolymers and the concentration of aqueous NaOH solutions.

Original languageEnglish
Pages (from-to)3913-3918
Number of pages6
JournalJournal of Applied Polymer Science
Issue number5
Publication statusPublished - Jun 5 2006
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Materials Chemistry
  • Surfaces, Coatings and Films
  • Chemistry(all)
  • Polymers and Plastics


Dive into the research topics of 'Preparation of nano- and microparticles through self-assembly of azobenzene-pendent ionomers'. Together they form a unique fingerprint.

Cite this