Borohydride-functionalized polydopamine-coated open cell polyurethane foam as a reusable soft structured material for reduction reactions: Application to the removal of a dye

Open cell polyurethane foams coated with mussel-inspired polydopamine can be used as support for borohydride anions through their complexation by the catechol groups of the polydopamine layer. This strong interaction prevents borohydride hydrolysis and oxidation, and based on the redox mediator properties of polydopamine, the so-functionalized polydopamine-coated open cell polyurethane foams can act as efficient and reusable soft structured materials for the reduction of methylene blue in aqueous solution without additional sodium borohydride (NaBH4). Very low amounts of released boron sub-products and very small potential of hydrogen (pH) increase are observed in comparison to previous processes using dissolved NaBH4. This considerably reduces the environmental impact of the reducing structured material on the treated wastewater compared to the latter. (c) 2018 American Institute of Chemical Engineers Environ Prog, 38: 329-335, 2019