Fabrication of multichannel microtubules by the self-assembly of pyridine-based macrocyclic compounds and their use for heavy metal ion adsorption

Multichannel microtubules (MMTs) of ∼1μm in the aperture diameter and ∼10μm in length have been fabricated via the self-assembly of a series of pyridine-based macrocyclic compounds synthesised by a simple condensation reaction of di(chlorocarbonyl)pyridine and diamine derivatives. The resulting MMTs bearing multiple pyridyl carboxamide groups provide an efficient host to bind heavy metal ions in water. The detailed self-assembly process to fabricate the MMT is demonstrated together with their adsorption capability for heavy metal ions such as Cu ²⁺, Ni ²⁺ and Zn ²⁺ in the aqueous solution.