Influence of copper(II) ions on the structure and properties of octodecyl propylenediamine vesicles

The amphiphiles of octodecyl propylenediamine could self-assemble into vesicles in pure water and aqueous solution of CuCl2 or Cu(NO3)2. It has been found that the structure and properties of vesicles are quite different when the copper(II) salt is added to the solution. The self-aggregate structure and properties of the vesicles have been characterized by means of UV-vis spectra, transmission electron microscopy, dynamic light scattering, small-angle X-ray diffraction, differential scanning calorimetry and surface tension. The results show that the Cu2+-coordinated amphiphiles adopt compressed tetrahedral structures and the partially interdigitated chain-packing model in bilayer membranes, which was influenced not only by the counterions but also by the ligands.