Innovative electrospun geopolymer/zeolite/ <scp>PVA</scp> composite membranes

Abstract

Abstract Innovative electrospun poly(vinyl alcohol) (PVA)–geopolymer–zeolite 13X composite membranes were successfully fabricated and systematically characterized. The optimal electrospinning solution was prepared by mixing ethanol with 8 wt.% PVA and 1 wt.% of inorganic powder (geopolymer, zeolite 13X, or geopolymer/zeolite composites containing 20 or 30 wt.% zeolite). The incorporation of the inorganic fillers into the PVA matrix led to significant improvements in thermal, mechanical, and adsorption properties. Thermogravimetric analysis (TGA) showed delayed degradation with differential thermal gravimetric analysis (DTG) peaks shifting from ~293°C (MGP) to ~313°C (MZ30), with total mass losses between 92.7% and 94.0%. Mechanical testing revealed that MGP exhibited the highest tensile strength (2.81 MPa) and elongation (227.8%), while MZ30 presented 1.72 MPa strength with improved flexibility (62.1% strain) compared to MZ20 (34.9%). Nitrogen physisorption analysis indicated surface areas ranging from 2.4 m 2 /g (MZ) to 24.3 m 2 /g (MZ30), with fibre diameters spanning 10.7–44.4 μm. Gas adsorption studies demonstrated that hydrogen uptake increased from 0.01 mmol g −1 in pure PVA to 0.08 mmol g −1 in MZ30, and CO adsorption improved from 0.03 to 0.08 mmol g −1 . In contrast, CO 2 uptake remained largely unchanged, with values between 0.21–0.66 mmol g −1 , close to that of pure PVA (0.66 mmol g −1 ). These results confirm that even at low filler content, the hybrid membranes display enhanced multifunctional performance, making them promising candidates for separation processes, filtration, catalytic supports, and protective coatings.