Biodegradable polycaprolactone/MXene nanocomposite nanofiltration membranes for the treatment of dye solutions

Background: The widespread application of polymeric membranes in water filtration has raised concerns on the disposal of the large amount of resultant solid waste. The aim of this research was the preparation of a new environmentally-friendly membrane using polycaprolactone (PCL) biodegradable polymer and its modification through the addition of hydrophilic MXene nanosheets (Ti3C2(OH)(2)). Methods: In this study, the nanosheets were synthesized and then characterized to confirm their layered structure and the presence of the hydroxyl group in them. The pure and also the modified PCL membranes were characterized thoroughly. Biodegradability of membranes was also evaluated through burial in compost. Significant findings: The results showed that the PCL membrane incorporated with 4 wt. % MXene exhibited the highest hydrophilicity. Also, all the nanocomposite membranes showed improved tensile properties and biodegradability. Filtration results implied that the membrane loaded with 4 wt. % MXene had the highest pure water permeance (PWP), which was almost 4 times as much as the pure PCL membrane (5.99 vs 1.43 L/ m(2).h.bar, respectively). Moreover, the membrane incorporated with 1 wt. % MXene provided 98.92% rejection of crystal violet (Mw of 407.98 g/mol, dye concentration in the feed solution: 50 ppm), which was only slightly lower than that of the neat PCL membrane (i.e., 99.38%). (c) 2021 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.