| 초록 |
Polyethyleneimine(PEI) and (Phenylthio)acetic acid(PTA) self assemble's Upper critical solution temperature(UCST) change was observed depending on pH and oxidizing agent(H2O2). Amino group of PEI and carboxyl group of PTA can self assemble because of electrostatic interaction. In low pH, Ionization degree of amino group decrease, self assembly will dismiss. In high pH, Ionization degree of carboxyl group decrease, self assembly will dismiss. Also in the presence of oxidizing agent sulfide group in PTA oxidized and become sulfone group. PTA will be more hydrophilic in oxidation condition because sulfone group is more hydrophilic then sulfide group. When PTA become more hydrophilic PTA is more likely to dissolve in aqueous solution rather than self assemble with PEI. As a result the more oxidizing agent in aqueous solution the UCST of PEI and PTA self assembly decrease and more the pH closes to the neutral pH the UCST decrease. |
