Macromolecular Nanotechnology Aggregation and solubilization of organic solvents and petrol/gasoline in water mediated by block copolymers Alexandra Mun ˜ oz-Bonilla a,b , Marta Ferna ´ndez-Garcı ´a b , Marı ´a L. Cerrada b , Giuseppe Mantovani a , David M. Haddleton a, * a Department of Chemistry, University of Warwick, Coventry CV4 7L, UK b CSIC, Instituto de Ciencia y Tecnologı ´a de Polı ´meros, C/Juan de la Cierva 3, 28006 Madrid, Spaı ´n Received 6 June 2007; received in revised form 10 July 2007; accepted 5 August 2007 Available online 5 September 2007 Abstract A series of AB and ABA block copolymers of pDEGMEMA-b-pCHMA and pCHMA-b-pDEGMEMA-b-pCHMA cyclohexyl methacrylate (CHMA) and di(ethylene glycol) methyl ether methacrylate (DEGMEMA) with M n ranging between 18,000 and 50,000 g mol 1 and PDI = 1.09–1.32 were prepared via copper(I) mediated living radical polymeriza- tion with pyridylmethanimine ligands. Aggregation properties were investigated using a combination of 1 H NMR, dynamic and static light scattering. For comparative purposes poly(CHMA) and poly(DEGMEMA) homopolymers were prepared. The CAC values estimated for the di- and triblock copolymers soluble in cyclohexane are lower than 0.005 g L 1 whereas the values found for block copolymers in methanol solutions are less than 0.070 g L 1 . DLS analysis showed the presence of micellar aggregates with diameters ranging from 25 to 40 nm with particle polydispersity indexes between 0.003 and 0.183. The pCHMA-b-pDEGMEMA-b-pCHMA micelles solubilized the aqueous phase in petrol/gasoline. The block copolymer-based micelles incorporate water within their hydrophilic domains, potentially overcoming a number of prac- tical problems such as the formation of biphasic mixtures in solvent blends due to undesired water accumulation. Ó 2007 Elsevier Ltd. All rights reserved. Keywords: Living radical polymerization; ATRP; Block copolymer; Gasoline 1. Introduction Block copolymers are materials which can undergo microphase separation by spontaneous self-assembly under appropriate conditions. This results in a diverse range of applications including polymeric surfactants and dispersants, nano-reser- voirs, controlled drug delivery, gene therapy agents and as compatibilization agents in polymer blends [1–6]. When a block copolymer is dissolved in a thermodynamically good solvent for one block and a correspondingly poor solvent for the second block reversible assembly to micellar aggregates can occur [7–9]. The formation and the structure of micelles or aggregates depend on different para- meters which include the nature and molecu- lar weight (MWt), composition, architecture and 0014-3057/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.eurpolymj.2007.08.017 * Corresponding author. Tel.: +44 2476 523256. E-mail address: D.M.Haddleton@warwick.ac.uk (D.M. Had- dleton). Available online at www.sciencedirect.com European Polymer Journal 43 (2007) 4583–4592 www.elsevier.com/locate/europolj EUROPEAN POLYMER JOURNAL MACROMOLECULAR NANOTECHNOLOGY