The nitroxide-mediated polymerisation (NMP) of poly(ethylene glycol) methyl ether methacrylate (PEGMA) with a small amount of styrene (S) as a comonomer was performed in water at 90 degrees C using 2,2'-azobis [2-(2-imidazolin-2-yl) propane] dihydrochloride (VA-044) as initiator and N-tert-butyl-N-(1-diethylphosphono- 2,2-dimethylpropyl) nitroxide (SG1) as nitroxide. The reaction was well-controlled and exhibited excellent livingness as evidenced by low dispersity and evolution of the molar mass distribution. The resultant macroalkoxyamine was then employed in the nitroxide-mediated polymerisation of 2-(diethylamino) ethyl methacrylate hydrochloride (DEAEMAH(+)Cl(-)) with a small amount of acrylonitrile (AN) in water at 90 degrees C. The resulting poly (PEGMA-co-S)-b-poly (DEAEMAH(+)Cl(-)-co-AN) polymer chains were converted to diblock copolymer nanoparticles after neutralizing with base. (C) 2017 Elsevier Ltd. All rights reserved.