Structural changes of water in poly(vinyl alcohol) hydrogel during dehydration

ポリビニルアルコールハイドロゲル中の水の構造変化

工藤 久志*; 石田 純一*; Syuu, G.*; 関根 由莉奈   ; 深澤 倫子*

Kudo, Kushi*; Ishida, Junichi*; Syuu, G.*; Sekine, Yurina; Fukazawa, Tomoko*

ポリビニルアルコール(PVA)ハイドロゲル中の水及びポリマーネットワークの構造変化のメカニズムを明らかにするため、ラマン分光法を用いて物理架橋及び化学架橋により作製したPVAゲルの構造評価を行った。ラマンスペクトルの変化より、ゲル中の水やポリマーネットワークの構造は含水率及び架橋方法に依存することを明らかとした。

To investigate the mechanism of structural changes of water and polymer networks with drying and swelling, we measured the Raman spectra of a physically cross-linked poly(vinyl alcohol) (PVA) hydrogel synthesized using the freezing thawing method. On the basis of the dependence of the frequency shifts on the PVA concentration of the original solution, it was found that the structure of the polymer network in the reswollen hydrogel becomes inhomogeneous due to shrinkage of the polymer network with drying. Furthermore, to investigate the effects of the cross-linking structure on the drying process, these results were compared with those of a chemically cross-linked PVA hydrogel synthesized using glutaraldehyde as a cross-linker. The results show that the structures of the polymer network and water change with the gel preparation process, cross-linking method, and drying and reswelling processes.