Micelles formation of polystyrene-co-poly (N-acryloylthymine) and its aggregation behavior induced by triple hydrogen bonding

Micelles of a new amphiphilic copolymer bearing pendant thymine groups, polystyrene-co-poly (N-acryloylthymine) (PS-co-PAT), were prepared in aqueous solutions. Transmission electron microscopy and laser light-scattering studies showed that the resultant spherical micelles were nanoscale with narrow size distribution. Moreover, ratio of hydrophilic and hydrophobic contents strongly influenced the hydrodynamic radius of the spherical micelles (113–227 nm). Upon exposure of the PS-co-PAT micelles to melamine, triple hydrogen bonding recognition between melamine and thymine resulted in the aggregation of polymer micelles, and the blue phase transparent solution of the polymer micelles was accordingly changed to turbid emulsion. The aggregation of micelles and hydrogen-bonding interaction between melamine and the PS-co-PAT shell was further confirmed by 1H NMR spectra and zeta-potential measurements. These results suggested that PS-co-PAT micelles could be a potential new vehicle for melamine recognition.