Short-life Micelle Formed by the System of Homopplymer PAA/ETC 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide Methiodide and the Study of the Mechanism

摘要

This paper studies the short life-time polymer micelles self-assembled by the PAA and the reaction productions of PAA and ETC. When the ETC was added into the PAA solutions, the micellization characterized by dynamic laser light-scattering (DLS) was carried out at room temperature. But the particles were not stable, they dissociated gradually in the solutions, just as they had a life-time. The formation and the degree of the disociation of the particles in relation to concentration, MR and time was characterized by DLS. The struction and morphology of the particles was characterized by TEM. As the particles dissociated, the intensity of the scattering light descent and the polarity of the inner side changed, which was shown by the ratio of I_1/I_3 in the pyrene emission spectrum. The stuctions of the particles were seen with the FT-IR test. For the reaction between PAA and ETC was rapid, only the production of the ETC molecules were tested by the ~1H NMR measurement. Through the measurements above, the mechanism of the dissociation was studied: first, the ETC cross-linked the molecules of PAA, the micelles were formed; then, the chemical bond breaking detached the ETC from the polymers, at the same time, the micelles dissociated. It was thought that, the life-time was related with the concentrations.