Evolution in the morphological behaviour of a series of fluorine-containing ABC miktoarm star terpolymers

Abstract

Fluorine-containing amphophilic polymers, as well as star polymers, have shown extremely abundant self-assembled morphologies because of microphase separation within the assemblies. Taking advantage of these characteristics, we prepared a series of ABC miktoarm star terpolymers with poly(ethylene glycol) (PEG) as a hydrophilic block, as well as poly(2-ethylhexylmethacrylate) (PEHMA) as a hydrophobic chain. Poly(1H,1H,5H-octafluoropentylmethacrylate) (POFPMA) was chosen as the third segment of terpolymers because of its super-hydrophobic/oleophobic characteristics. The terpolymers were synthesised via atom transfer radical polymerisation (ATRP), single electron transfer living radical polymerisation (SET-LRP) and azide-alkyne Huisgen cycloaddition (click reaction). Herein, we investigated the self-assembled behaviours of nanoaggregates formed by varying the length of POFPMA and PEHMA chains of the terpolymers in aqueous solution. The tunable miktoarm star polymer favoured the transformation of nanoassemblies, from patchy spherical micelles to patchy spherical aggregates, spherical micelles, egg-like micelles, segmented-worm micelles, shuttle-like micelles and vesicles. Interestingly, special discontinuous aggregations arranged into lines were observed, which has been seldom found before. The independent control of both of the hydrophobic parameters of terpolymers enhanced the nanostructures of polymeric assemblies of ABC miktoarm terpolymers, providing a reliable method to explore the compartmentalisation behaviours of soft matter assemblies.