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

Abstract

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.