Hollow porous carbon spheres (HPCSs) doped thin-film nanocomposite membrane for efficient organic solvent nanofiltration

A novel thin film nanocomposite (TFN) membrane was prepared for efficient organic solvent nanofiltration (OSN) by doping hollow porous carbon spheres (HPCSs) nanoparticles in polyamide separating skin-layer through interfacial polymerization and solvent activation techniques. The undoped thin film composite (TFC) membrane was also prepared for comparison. In the interfacial polymerization process, the excellent adsorption properties of HPCSs lead to the unstable diffusion of m-phenylenediamine monomers from the aqueous phase to the oil phase, resulting in the formation of a ridge-valley morphology on the membrane surface. This ridge-valley morphology can effectively increase the contact area between the membrane and the solvent, which in turn improves the permeation capacity. The as-synthesized optimal TFN-HPCSs-200 membrane exhibits superior OSN performance. The methanol permeation capacity is 11.51 L m-2h-1 bar-1, which was 1.42 times of that of the TFC membrane. Meanwhile, the retention rate of RDB dye for TFN-HPCSs-200 membrane is maintained at a high level (97.50%). Furthermore, it is noteworthy that the prepared TFN-HPCSs-200 membrane maintained stable solvent resistance and long-term stability after immersion in a strong polar DMF solvent at 80 degrees C for 5 days, implying that TFN-HPCSs membranes have potential for long-term application in industrial OSN processing.