Modifying Cellulose Acetate Mixed-Matrix Membranes for Improved Oil–Water Separation: Comparison between Sodium and Organo-Montmorillonite as Particle Additives

Abstract

In this study, cellulose acetate (CA) mixed-matrix membranes were fabricated through the wet-phase inversion method. Two types of montmorillonite (MMT) nanoclay were embedded separately: sodium montmorillonite (Na-MMT) and organo-montmorillonite (O-MMT). Na-MMT was converted to O-MMT through ion exchange reaction using cationic surfactant (dialkyldimethyl ammonium chloride, DDAC). Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) compared the chemical structure and composition of the membranes. Embedding either Na-MMT and O-MMT did not change the crystallinity of the CA membrane, indicating that the nanoclays were dispersed in the CA matrix. Furthermore, nanoclays improved the membrane hydrophilicity. Compared with CANa-MMT membrane, CAO-MMT membrane had a higher separation efficiency and antifouling property. At the optimum concentration of O-MMT in the CA matrix, the pure water flux reaches up to 524.63 ± 48.96 L∙m−2∙h−1∙bar−1 with over 95% rejection for different oil-in-water emulsion (diesel, hexane, dodecane, and food-oil). Furthermore, the modified membrane delivered an excellent antifouling property.

Cigarette Butt Waste as Material for Phase Inverted Membrane Fabrication Used for Oil/Water Emulsion Separation

“…This is followed by CA and PSF membranes with the surface water contact angles of 74.5 and 70.23°, respectively. The surface water contact angle of plain CA membrane from commercial polymers in this study is within the range reported earlier of 50-60° [38][39][40], which can be attributed to the variation surface structure and fabrication parameters and possibly due to the presence of impurities that can be further investigated as the follow-up study. These findings are encouraging and show that a CA membrane based from cigarette butt waste potentially possess a high clean water permeability and good anti-fouling property, at least when compared with the PVDF and PSF membranes samples used as a reference in this study.…”

“…Polymer purification was shown effective in improving the structure and performance of the resulting membranes [42]. The spectra shown in Figure 6 resemble the one obtained for the phase inverted membrane prepared from the commercial CA polymer [40,41]. The presence of impurities is hardly seen from the spectra, indicating that the spectra associated with them might be overlapping with the spectra associated with CA.…”

Infusion of Silver–Polydopamine Particles into Polyethersulfone Matrix to Improve the Membrane’s Dye Desalination Performance and Antibacterial Property

“…In addition, PESPDA0.3 and PESAg-PDA0.3 had similar thickness. During the phase inversion process, the hydrophilic nanofillers enhanced the demixing rate, thus resulting in a thicker membrane [56]. Figure 5a reveals that gaps between peaks and valleys on the PES were uniform and smooth, indicating the low surface roughness of the investigated membranes.…”

“…Prior to the nanofiltration test, membranes were washed using deionized water. Membranes were installed in a lab-scale crossflow filtration setup, which is similar to our previous work [56]. Before measuring the pure water flux, membranes were prepressurized at 4.5 bar for 1 h to ensure a steady-state condition.…”

“…In addition, PES PDA0.3 and PES Ag-PDA0.3 had similar thickness. During the phase inversion process, the hydrophilic nanofillers enhanced the demixing rate, thus resulting in a thicker membrane [56].…”