Fabrication of novel chitosan/PAN/magnetic ZSM-5 zeolite coated sponges for absorption of oil from water surfaces

In the present study, the chitosan (bottom layer)/polyacrylonitrile (top layer, PAN) nanofibers were coated on the sponge surface. The synthesized magnetic Fe3O4- ZSM-5 nanozeolites have been loaded into the chitosan/PAN nanofibers to increase the performance of nanofibers toward absorption of lubricating oil, motor oil and pump oil from water surfaces. Scanning electron microscope (SEM), Transmission electron microscope (TEM) and X-ray diffraction (XRD) analysis were used to characterize the synthesized nanozeolites. The morphology and wettability of nanofibers were determined using SEM and water contact angle tests. The influence of Fe3O4- ZSM-5 nanozeolite content and chitosan/PAN/Fe3O4- ZSM-5 nanofiber thickness was evaluated on the potential of sponges for oils absorption. The maximum capacity of the chitosan/PAN/Fe3O4- ZSM-5 nanofibers coated sponges for absorption of motor oil, lubricating oil and pump oil was found to be 99.4, 95.3 and 88.1 g/g, in Fe3O4- ZSM-5 2 wt.% and nanofiber thickness of 12 μm (chitosan layer of 2 μm and PAN layer of 10 μm). The reusability of nanofibrous sponges showed that the hydrophobic chitosan/PAN/Fe3O4- ZSM-5 nanofibers coated sponges can be easily reused in water-oil separation for many cycles.