Novel cellulose acetatepropionate-halloysitecomposite membranes with improved permeation flux, salt rejection, and antifouling properties

The fabrication of new membranes with improved performance for water desalination and other treatment is still an important strategy to overcome worldwide water scarcity and quality problems. In this study, cellulose acetate propionate/halloysite nanotube (HNT) composite membranes were prepared using the phase-inversion process, applying different concentrations of HNTs ranging from 0 to 0.11 wt%. The composite membranes' physicochemical properties were examined using thermogravimetric analysis, field emission scanning electron microscopy, atomic force microscopy, Fourier transform infrared spectroscopy, and contact angle measurements. A dead-end filtration system was applied when examining the membranes' performance. The results showed clear improvements in the membrane hydrophilicity, permeability, salt rejection, antifouling, and stability properties with the addition of HNTs. The contact angle decreased from 69 degrees to 38 degrees, while the water uptake increased from 18% to 33%. Moreover, the permeation flux increased from 8 to 23 L m(-2)h(-1)at 1 bar, corresponding to an improvement of about 188%. The membrane containing 0.08 wt% of HNTs showed the optimal results, exhibiting salt rejection of 85% for sodium chloride and 95% for magnesium sulfate, corresponding to improvements of 109% and 154%, respectively, in addition to an improved flux recovery of 80% determined after 120 minutes.