Abstract
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 language | English |
|---|---|
| Pages (from-to) | 3913-3918 |
| Number of pages | 6 |
| Journal | Journal of Applied Polymer Science |
| Volume | 100 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - Jun 5 2006 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Polymers and Plastics
Cite this
Preparation of nano- and microparticles through self-assembly of azobenzene-pendent ionomers. / Mori, Takeshi; Yuyama, Keijiro; Narita, Kanae; Minagawa, Keiji; Haraguchi, Masanobu; Tanaka, Masami.
In: Journal of Applied Polymer Science, Vol. 100, No. 5, 05.06.2006, p. 3913-3918.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Preparation of nano- and microparticles through self-assembly of azobenzene-pendent ionomers
AU - Mori, Takeshi
AU - Yuyama, Keijiro
AU - Narita, Kanae
AU - Minagawa, Keiji
AU - Haraguchi, Masanobu
AU - Tanaka, Masami
PY - 2006/6/5
Y1 - 2006/6/5
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=33646373645&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33646373645&partnerID=8YFLogxK
U2 - 10.1002/app.22762
DO - 10.1002/app.22762
M3 - Article
AN - SCOPUS:33646373645
VL - 100
SP - 3913
EP - 3918
JO - Journal of Applied Polymer Science
JF - Journal of Applied Polymer Science
SN - 0021-8995
IS - 5
ER -