Neutral linear amphiphilic homopolymers prepared by atom transfer radical polymerization

Abstract

A novel neutral amphiphilic monomer bearing tri(ethylene glycol) monomethyl ether as the hydrophilic part and a decyl group as the hydrophobic part was successfully synthesized and its structure was confirmed by NMR. The monomer was readily polymerized via atom transfer radical polymerization (ATRP) resulting in control over the molecular weight and a narrow dispersity. As a result of the contrasting solubilities of the two side chains, the amphiphilic homopolymers readily self-assembled in a variety of solvents, forming micelles in polar environments and reverse micelles in non-polar environments. The critical micelle concentrations (CMCs) were determined by fluorescence spectroscopy as 0.12 mg mL⁻¹ in hexanes solution and 0.002 mg mL⁻¹ in aqueous solution. The average diameter of the self-assembled aggregates in aqueous solution was calculated by dynamic light scattering (DLS) to be ∼180 nm and this aggregate size was confirmed by transmission electron microscopy (TEM).