| 초록 |
The colorless spiropyran (SP) undergoes structure isomerization to colored Merocyanine (MC) form under various stimuli such as mechanical force, heat and pH etc. The purple Merocyanine (MC) form converts the protonated merocyanine(MCH) form with yellow color in acidic solution. In this study, we synthesized the spiropyran molecule grafted poly (ethylene glycol) diacrylate (PEGDA) as cross-linker (SP-PEGDA) to fabricate pH responsive bi-layered hydrogel. The expansion ratio of each layer in the bi-layered hydrogel was controlled with the synthesized SP-PEGDA crosslinker and conventional methylenebisacrylamide(BIS), respectively. The various curvatures were produced by self-folding of bi-layered hydrogel with different expansion ratios of each layer on pH conditions. Furthermore, we would be confirmed the color transition of bi-layered hydrogel crosslinked by SP-PEGDA in acidic solution by hydrogel shrinkage. |
