Synthesis and studies of self-organization of amphiphilic copolymers into nano-micellar particle by light scattering and (1)H-NMR relaxation

This thesis includes five portions i.e. the background and introduction, the chapter of the synthesis, the chapter of the measurement using 1H-NMR relaxation time, the chapter of the measurement using light scattering, and the conclusion. In the first portion, we introduced the fundamental principles that regard with our system i.e. nano-micellar particles based on polyethylene glycol (PEG)-based amphiphilic copolymers, and the techniques that used to measure the properties of the particles.; The preparations of the copolymers were explained in Chapter 2, which reports the synthesis of a number of functional monomers including 2-(8-bromooctoxy) tetrahydropyran, 12-bromo-1-t-butoxydodecane, and 12-bromo-1-(monomethoxytrityloxy)dodecane from 12-bromooctanol, which is commercially available. These functional monomers were then used to polymerize with poly(ethylene glycol) using dibutyltin diacetate as catalyst. During chemical polymerization of these functionalized monomers with poly(ethylene glycol) insoluble gel like product was obtained.; Chapter 3 reports the studied about the aggregation or micellization of the non-functionalized PEG-based amphiphilic copolymer using 1H-NMR relaxation time. From that experiment, the aggregation behavior of the copolymers in different solvents was studied so that a logical model of the micellar particles in aqueous solution was built. This experiment provided a genuine way to discover the influences of aggregation or micellization of the copolymers in different solvents on changing the local environments of the protons physically. This might become an effective method to monitor the influences of structural modifications such as adding functional group onto the hydrophobic segments on the formation of micellar particles.; Chapter 4 reports the experiments that measure the micellar particular properties such as the size, the shape, the aggregation number, and the critical micelle concentration (CMC) of copolymers in water using light scattering technique, which was carefully tested and evaluated before using. The CMC was evaluated as c.a. 0.6 to 0.7 mg/ml. The sizes (root-mean-square-radius) of our micellar particles are in the range of c.a. 17 to 30 nanometers. They were found proportional to the chain length of the PEG that used to form the copolymers and strongly influenced by the functionalization of the hydrophobic segments. The sizes of the particles that encapsulate a variety of drugs were also measured, which were highly depended on the functionalization of the hydrophobic side chains.