Squaramide-based supramolecular gels for the removal of organic dyes from water matrices

A novel family of symmetric squaramide-based LMWGs has been synthesised, functionalized with both dansyl moieties and alkyl chain spacers of different lengths (n = 3 and n = 4 named L1 and L2, respectively). L1 and L2 are able to form hydrogels in the DMSO : H₂O mixture in different ratios and concentrations. The gels obtained were characterized by means of rheology, TEM and small angle X-ray scattering (SAXS). Afterwards, the adsorption properties of these materials were studied and the gels were used for the removal of dyes, in particular Nile Blue A, Rose Bengal and Naphthol Yellow S from water samples. The reported results demonstrated the potential use of these materials for the removal of dyes in real polluted water matrices.