Membrane pH responsibility as a remote control for pore size arrangement and surface charge adjustment in order to efficient separation of doxorubicin antitumor drug

To separate the antitumor drug doxorubicin by polyacrylonitrile (PAN)- polyamide (PA) thin film composite (TFC) membrane, different factors were exploited including adjusting the size of pores, membrane superficial charge, and pH of the medium. For this purpose, copper oxide nanoparticles and silica hydrogel were added to the superficial PA layer and PAN sublayer, respectively, whereby SiiPAN-CujPA membranes were synthesized. Energy Dispersive X-Ray Spectroscopy (EDS) test confirmed the presence of Cu in the superficial layer and Si in the sublayer. The effect of Si on enhancing the sublayer porosity was proven by scanning electron microscopy (SEM) images, and the impact of Cu on increasing the crosslinking of the superficial layer was demonstrated by attenuated total reflection-fourier transform infrared (ATR-FTIR) test. The results indicated that adding silica hydrogel to the raw Si0PAN-Cu0PA membrane, through 22% increase in membrane porosity, caused elevation of flux from 12.3 to 27.9 LMH for Si3PAN-Cu0PA membrane. Meanwhile, the level of rejection and flux recovery of this membrane eventually reached 77 and 58% respectively. Addition of copper oxide nanoparticles to the Si3PAN-Cu0PA membrane, through reducing the size of membrane pores from 6.2 to 4.7 nm, caused the Si3PAN-Cu3PA membrane rejection to grow to 86% and flux recovery to 97%. Eventually, upon elevating the pH from 2 to 8, because of shrinkage of the membrane pores according to the Brunauer–Emmett–Teller (BET) analysis, increased superficial charge and zeta potential as well as reduction of the membrane pHPZC, the doxorubicin rejection was boosted to 99.4%.