An amphiphilic pillar[5]arene: synthesis, controllable self-assembly in water, and application in calcein release and TNT adsorption

An amphiphilic pillar[5]arene was made. It could self-assemble to form vesicles and multiwalled microtubes in water. Dynamic light scattering, transmission electron microscopy, scanning electron microscopy, atomic force microscopy, and UV-vis and FTIR spectroscopy were employed to characterize its self-assembly process and the resultant assemblies. The vesicles could encapsulate calcein within their interiors under neutral conditions and release it in response to a decrease in pH. The microtubes, which have primary amine groups on their surfaces, could adsorb TNT through donor-acceptor interactions.