Fabrication of Ultrafiltration Membranes from PAN Composites with Hydrophilic Particles for Separation of Heavy Oil Components

In this work, membranes were obtained from PAN with the addition of particles of graphene oxide (GO), PAN pyrolyzed under the influence of IR radiation (IR-PAN-a) and nanodiamonds (ND). The pore structure of the obtained membranes was studied. It has been shown that the addition of particles slightly reduces the average pore size of the membranes from 17 to 12–15 nm, which leads to a decrease in the membranes water permeance from 158 to 80.9–119.9 kg/m² h bar. At the same time, the addition of particles led to hydrophilization of the surface—the water contact angle decreased from 65° to 48°–55°, which contributed to an increase in the flow of oil solutions in toluene by 2–3 times compared to the PAN membrane. At the same time, the addition of GO and IR-PAN-a contributed to a significant increase in the irreversible membrane fouling. On the other hand, the addition of nanodiamonds not only reduced the overall membrane fouling and increased the permeability of the separation mixture from 4.93 to 8.47 kg/m² h bar, but also made it possible to recover more than 96% of the pure toluene flux. The membranes rejection with the addition of ND in the filtration of oil solutions in toluene 10 g/L was 85–89%.