We have studied the micellization behavior of tertiary amine methacrylate-based diblock copolymers, comprising the hydrophobic poly[2-(diethylamino)ethyl methacrylate] (PDEA) and hydrophilic/polyelectrolyte poly[2-(dimethylamino)ethyl methacrylate] (PDMA) blocks. Revealed by small-angle X-ray scattering (SAXS) and dynamics light scattering, micelle size of the PDMA(m)-b-PDEA(n) diblock copolymer in aqueous solution depends sensitively on the comonomer ratio n/m, molecular weight M-w, solution temperature, and solution pH values. Aggregation number is found to follow an empirical relation of N proportional to (n/m)(1.6), disregarding the molecular mass. With n/m = 0.5, M-w approximate to 12,000, and pH = 7.6, the diblock copolymer forms spherical core-shell micelles at 23 degrees C, with a PDEA-core radius of 52 angstrom, a PDMA-shell thickness of 27 angstrom and an aggregation number of 127. (C) 2012 Elsevier B.V. All rights reserved.