Effective interfacially polymerized polyarylester solvent resistant nanofiltration membrane from liquefied walnut shell

Walnut shell, an agricultural waste, has not been efficiently utilized so far. In this paper, walnut shell was liquefied first, followed by characterization of XPS and ATR-FTIR. It is shown that syringylphenol and guaiacylphenol are contained in the walnut shell. A novel organic solvent resistant nanofiltration (OSN) membrane was prepared by liquefied walnut shell (LWP) and trimethyl chloride (TMC) on the crosslinked polyetherimide substrate via interfacial polymerization method. The results showed that LWP and TMC formed polyarylester toplayer. The NF-2LWP membrane maintained stable N,N-Dimethylformamide (DMF) permeance of 2.2 L m−2 h−1 MPa−1 and rejection of 98% for crystal violet (CV, 407.98 g mol−1) in 36 hours continuous separation process. Furthermore, guaiacol (GA), a component of LWP, was used to prepare an OSN membrane, Compared with NF-LWP membrane, NF-GA membrane shows good performance in the separation of tetrahydrofuran (THF) with the rejection of 96% for rose bengal (RB, 1,017.64 g mol−1) and the permeance of 76 L m−2 h−1 MPa−1. This study not only provides a good way for the efficient recycling of walnut shell, but also provides a new component for the preparation of polyarylester OSN membrane.