The micellization process of poly(ethylene glycol)-b-poly(4-vinylpyridine) (PEG114-b-P4VP107) and poly(N-isopropylacrylamide)-b-poly(4-vinylpyridine) (PNIPAM53-b-P4VP260) in acidic aqueous solutions with varying degree of protonation of P4VP was investigated by NMR.When the micelles began to form due to the hydrophobicity of P4VP was resulted from its deprotonated

the NMR signal of pyridyl stayed unchanged.The signal kept becoming weaker with the decrease of the degree of protonation until no NMR signal can be detected at the point that all the 4VP unites were deprotonated.At the mean time

the spin-lattice relaxation time (T1) decreased significantly when the P4VP blocks began to transfer to aggregation from their unimer state.The results indicated that micelles of PEG114-b-P4VP107were formed at the degree of protonation of 0.54

while the micelles of PNIPAM53-b-P4VP260 were achieved at the point of 0.58. The twodimensional Nuclear Overhauser Effect (2D NOE) signal was also detected when the micelle solutions made separately from PEG114-b-P4VP107 (at the degree of protonation of 0.54) and PNIPAM53-b-P4VP260(at the point of 0.58) were mixed

which indicated the exchanges of macromolecules between micelles and the diblock copolymer in solution.However

no corresponding 2D NOE signal appeared while the micelle solutions were achieved at lower degree of protonation.This fact might imply the different mobility of the P4VP blocks

which formed the micelles core

at different degree of protonation.