Construction of self-healable and recyclable waterborne polyurethane-MOF membrane for adsorption of dye wastewater based on solvent etching deposition method

The treatment of dye wastewater by combining metal–organic framework (MOF) and polymer adsorbent membranes has attracted extensive attention. However, most of the polymer/MOF composite will encounter problems such as the poor compatibility, the holes of MOF are easily blocked by polymer chains, moreover, the study about the self-healable and recycle properties have never been done. To fill this gap, this research puts forward a novel solvent etching deposition method, combining waterborne polyurethane containing dynamic disulfide bonds (WPU-SS) with MOF (UiO-66-NH2) to prepare a self-healable and recyclable adsorption membrane (WPU-SS-MOF). The results show that WPU-SS-MOF membrane has excellent mechanical and self-healing properties, the tensile strength and elongation at break of WPU-SS-MOF membrane are 5.16 MPa and 1117.1%, respectively, and the self-healing efficiency can reach 96.1%. The adsorption experiments results show that WPU-SS-MOF has excellent adsorption and recycling capacity for the anionic dyes of methyl orange (MO) and Congo red (CR), and the removal efficiency remained above 80% after 5 cycles. In summary, this is the first time to combine the function of adsorption of MOF with WPU-SS by a solvent etching deposition method, which provides vast application foreground for dye wastewater treatment.