| 초록 |
pH and photo sensitive microgels were prepared by crosslinking polyethyleneimine(PEI) and carboxymethoxycoumarin(CMC). 7-hydroxycoumarin was reacted with ethyl bromoacetate to form 7-ethoxycarbonylmerhoxycoumarin, which was subsequently hydrolyzed to get CMC. Dimerizaton of CMC increases under irradiation of a light at λ=365nm. Microgels were formed in the range of pH 5.0 to pH 9.0 before and after UV irradiation possibly due to the ionic interaction between PEI and CMC or the dimerization between CMC which interacted with PEI. Under strong acidic condition (e.g., pH3.0), microgels were not exist because there was no interaction between PEI and CMC. The image of microgels observed on a scanning electron microscope (SEM) and there was no significant difference between the microgels before and after UV irradiations. |
