Design and Fabrication of the Evolved Zeolitic Imidazolate Framework-Modified Polylactic Acid Nonwoven Fabric for Efficient Oil/Water Separation

Design of durable and recyclable superhydrophobic materials for oil/water separation is a major concern in the field of wastewater treatment. Functionalization of a biodegradable matrix with controllable grown crystals brings out a new research perspective. In this study, multiscale zeolitic imidazolate frameworks (ZIFs) were grown and decorated on a polylactic acid (PLA) nonwoven fabric (NWF) to construct a superhydrophobic material by an in situ growth method and a spraying process. The stable superhydrophobic layer contains two kinds of ZIF crystals showing microscale flake-like structures and nanoscale particles. The morphology and surface energy of such a hierarchically structured ZIF-modified PLANWF is controllable by the adjustment of experimental parameters. The as-prepared PLA hybrid materials exhibit high separation efficiency and recyclability as for water-nitromethane and water-toluene mixtures. Based on the wetting envelopes of the ZIF-modified PLA material, its separation performance for various oil/water mixtures can be preliminarily assessed before the application.