Advanced CO₂ capture: Hydrophobic PVDF membranes integrated with stearic-acid modified ZnO nanohybrids

Backgrounds: Efficient CO₂ capture is necessary for minimizing greenhouse gas emissions and addressing climate change while also playing a critical role in natural gas purification and flue gas treatment. Membrane-based gas absorption technologies offer a promising solution owing to their potential to address high energy demands and operational inefficiencies. However, their carbon capture performance is critically hindered by membrane-wetting. Methods: A facile method is employed to enhance the hydrophobicity of PVDF membranes by incorporating stearic acid-modified ZnO nano hybrids into the polymer matrix. The fabricated membranes were tested using a simulated natural gas mixture, and their structural and functional improvements were characterized using various analytical techniques. Key findings: The hybrid membranes exhibited enhanced hydrophobicity, with the water contact angle showing an increase from 84.8° to 106.2°. The addition of ZnO nano hybrids enhanced the membrane properties, resulting in a CO₂ absorption flux of 2.3 × 10⁻³ mol/m²/s that was 156 % higher than pristine PVDF membranes, while reducing the membrane mass transfer resistance from 1810.1 s/m to 1184.3 s/m. These results validate the potential of employing this eco-friendly and feasible modification approach for developing high-performance PVDF membranes for gas absorption applications.