Journal article
Small-angle scattering study of mesoscopic structures in charged gel and their evolution on dehydration
Department of Physics, Technical University of Denmark1
Chiba University2
Kyushu University3
The Danish Polymer Centre, Department of Chemical and Biochemical Engineering, Technical University of Denmark4
Department of Chemical and Biochemical Engineering, Technical University of Denmark5
Oak Ridge National Laboratory6
Mesoscopic structures, with length scales similar to10(2) Angstrom, were investigated by small-angle X-ray and neutron scattering (SAXS and SANS) in several N-isopropylacrylamide-sodium acrylate (NIPA-SA) copolymeric hydrogels with varying [NIPA]/[SA] ratios and water contents. The SAXS experiments reveal that, depending upon the [NIPA]/[SA] ratio, the dehydrated NIPA-SA gel shows two mesoscopic structures: one consists of randomly distributed SA-rich islands in NIPA matrix, while the other is a microphase-separated structure, composed of NIPA-rich and SA-rich domains.
In addition, the SANS experiments reveal the mesoscopic structural features during the dehydration process. As the concentration of the network polymers increases, NIPA-rich and water-rich domains segregate in the gel. Then, an electrostatic interaction between the segregated domains induces a microphase-separated structure in the limit of the dehydrated NIPA-SA gel.
Language: | English |
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Year: | 2003 |
Pages: | 6300-6308 |
ISSN: | 15205207 and 15206106 |
Types: | Journal article |
DOI: | 10.1021/jp0277816 |