Effect of general montmorillonite and Cloisite 15A on structural parameters and performance of mixed matrix membranes contactor for CO2 absorption

• Less thermodynamic/kinetic solution stabilities due to addition of clay fillers.
• Formation of finger-like macrovoids enhanced by the addition of clay particles.
• Porosity and permeance of MMMs were increased; more apparent in Cloisite 15A MMMs.
• Surface contact angle and wetting resistance of MMMs increased by clay loading.
• MMMs showed better CO2 absorption performance than plain PVDF.

Polyvinylideneflouride (PVDF) hollow fiber mixed matrix membranes (MMMs) were fabricated through wet phase inversion method using general MMT and Cloisite 15A as inorganic fillers. The effect of clay filler loadings (1, 3 and 5 wt% of polymer), their particle size and hydrophobicity on the membrane morphology, structure and performance in gas–liquid contacting process were investigated. The fabricated MMMs were characterized by scanning electron microscopic (SEM), gas permeation test, hydrophobicity, wetting resistance and CO2 absorption test. As expected, MMMs showed asymmetrical structure, differing in finger-like portion, porosity and pore size. The fabricated MMMs with higher finger-like area and surface porosity showed higher permeance than plain membrane. Furthermore, the wetting resistance in terms of surface hydrophobicity and liquid entry pressure of water increased with loading. From the point of view of physical CO2 absorption, the membranes incorporated with small particle size filler (general MMT-filled PVDF membranes) exhibited higher absorption fluxes than those embedded with large particle size fillers. The highest absorption flux for membrane containing 1 wt% general MMT is 1.0 × 10−3 mol m−2 s−1 at the flow rate of 3.1 m s−1. That flux was approximately 54% and 82% higher than the flux of MMMs with embedded Cloisite 15A of the same loading and plain PVDF membrane, respectively. The obtained flux of synthesized membrane was superior compared to several in-house made and commercial membranes.