Vanadium oxide intercalated with polyelectrolytes: Novel layered hybrids with anion exchange properties

Novel anion exchange hybrid materials were developed by the insertion of poly(diallymethylammonium chloride) (PDDACl) and poly(allylamine hydrochloride) (PAHCl) polyelectrolytes into V ₂O ₅ interlayer spaces using hydrothermal treatment and were used to host an anionic cyanine dye. A systematic study of the hybrid material synthesis by direct in situ reaction of PDDACl and PAHCl polycations with V ₂O ₅ powders showed that the interlayer space of V ₂O ₅ expands from 0.44nm to 1.40nm and 1.80nm upon intercalation of PDDACl and PAHCl polyelectrolytes, respectively. X-ray photoelectron spectroscopy and DR UV-Vis-NIR spectroscopy revealed that some V ⁵⁺ sites were reduced to V ⁴⁺ during the intercalation of the polyelectrolytes, these acted as both charge balancing entities for the negative oxide sheets and carriers for exchange sites located in the V ₂O ₅ interlayer space. The interlayer separation is consistent with the existence of coiled conformation of the polycations. The hybrid materials produced [PDDACl] _0.24[PDDA] _0.29V ₂O ₅ and [PAHCl] _0.28[PAH] _0.47V ₂O ₅, exhibited approximately 45.0% and 37.0% of chloride ions still available for anionic exchange, respectively. These materials were used to encapsulate a cyanine anionic dye. The presence of the dye was evidenced in the [PDDACl] _0.24[PDDA] _0.29V ₂O ₅ by significant fluorescence, with emission peak centered at 617nm.