A high-performance polyurethane sponge for the detection, adsorption and separation of Cu2+ ions

Abstract

The simultaneous detection and separation of copper ions is important. In this study, a fluorescent chemosensor (a copper sensitive molecule), was prepared using 6-bromo-benzo[de]isochromene-1,3-dione as a precursor. The as-prepared fluorescent molecule contains a hydroxyl group and an aminoquinoline moiety. The hydroxyl group enables the fluorescent molecule to anchor to a porous polyurethane (PU) sponge. The chemosensors still retained their recognition ability after they were introduced to PU. Upon the addition of Cu²⁺ ions to the PU sponge, both the color and the fluorescence intensity changed, suggesting that the chemosensor-functionalized PU sponges could be used as a Cu²⁺ ion sensor. The copper ions could also accumulate and be enriched on the sponges. The adsorption capacity of the PU sponge (containing 2 wt% of the chemosensor) reached 97.26 mg g⁻¹, which was higher than that of the solid PU membranes (52.62 mg g⁻¹). These polymeric, highly sensitive chemosensors may potentially be applied in the detection of water pollution generated by sources such as electroplating and drain outflow.