CMPs membranes prepared using electrostatic spinning as a template for efficient oil-water separation

Abstract

The development of efficient oil-water separation membrane technology is of great important for elimination of the serious environmental pollution issues caused by the frequent oils-spill or organics leakages in modern industry. Herein, we report the creation of conjugated microporous polymer membranes (CMPs@PMMA/PVDF), which were synthesized by a Sonogashira-Hagihara cross-coupling reaction using 1,3,5-triethynylbenzene and 2,6-dibromophenol as monomers in the presence of a template membrane prepared using poly (vinylidene fluoride) and poly (methyl methacrylate) as mixed solution via electrostatic spinning method, for efficient oil-water separation. The as-synthesized CMPs membrane shows excellent hydrophobicity with a water contact angle (WCA) of 150.8º and high permeate flux ( 865.8 L m−2 h−1). The tensile strength of CMPs@PMMA/PVDF was measured to be 3.13 MPa with an elongation of 10.32%. The TGA curve of CMPs@PMMA/PVDF membranes shows high thermal stability with mass loss decreasing by only 15.89% when the temperature rises to 414.3 ºC. Driven by gravity alone, the resulting membrane shows outstanding oil-water selectivity for oil-water separation (with a separation efficiency of up to 99.9%), its separation efficiency almost remains unchanged after 10 cycles with cyclohexane as the oil phase, and the separation efficiency still maintains up to 98.9% even after 50 cycles. In addition, the 3D-CMPs membrane also performs well in the separation of oil-water mixtures, and the separation efficiencies of various water-in-oil mixtures are maintained above 98.6% after ten cycles, showing that the CMPs membrane materials may have great potential for a broad application in the field of separation of oil-water mixtures.