LAUSR

Abstract A novel amphiphilic random polyurethane (APU) having both hydrophilic (Di(ethylene glycol), DEG) and hydrophobic/emulsifying (Oleic acid based dihydroxy fatty acid, DHA) constituents was synthesized and characterized for micellization utility. In order to prepare the dihydroxy acid, epoxidized methyl oleate was ring-opened in aqueous solution followed by alkali hydrolysis. The chemical structure of DHA and APU was ascertained by FT IR and 1H NMR spectroscopies. APU showed self-assembled structures in aqueous and nonpolar organic media by direct dissolution method. The morphologies of these nanoparticles were investigated by field emision scanning electron microscopy (FE SEM), atomic forec microscopy (AFM), dynamic light scattering (DLS), 1H NMR spectroscopy and water contact angle (WCA) measurement. The environment-dependent formation of APU micellar arrangements, that is, conformational inversion from micelle to reverse micelle-type structures in response to polarity of the solvent was investigated by 1H NMR spectroscopic technique. The ability of the nanoparticles for encapsulation and release of a hydrophobic guest molecule, Nile red, was characterized by UV–vis spectroscopy.