The micellization of well-defined PS-b-PEO-b-PS triblock copolymers in selective solvent has been characterized using ^1H NMR and TEM technologies. The ^1H NMR investigations reveal that the peaks of phenyl ring protons show up in CHCl~3 (good solvent) and disappear in water (selective solvent). Therefore, the triblock copolymers elf- asemble reversibly to form micelles with a core composed of the insoluble PS blocks and a shell of water-solvated soluble PEO blocks. The shape of micelles have been observed and the radius have been measured by TEM. The experimental results show that the size of micelles is polydispersed, ranging from 100 to 500nm. The possible reason has been discussed.

Key words: PHOSPHONIC ACID ESTER, FURANONE P, PHOSPHOROUS ACID ESTER, ELEMENTAL ANALYSIS, INFRARED SPECTROPHOTOMETRY, ULTRAVIOLET SPECTROPHOTOMETRY, PROTON MAGNETIC RESONANCE SPECTROMETRY, C13 NMR SPECTROMETRY, MASS SPECTROGRAPHY, X-RAY DIFFRACTION ANALYSIS