Hybrid Microcrystalline Cellulose-Polyvinylidene Fluoride Membrane for Simultaneous Carbon Dioxide Adsorption and Hydration

The alarming high atmospheric carbon dioxide (CO2) concentrations necessitate the development of effective, low-energy, and eco-friendly CO2 capture technologies. Polymeric membrane reactors are promising for gas separation due to their ease of fabrication and low energy requirements. However, they often suffer from low mechanical strength, thermal stability, permeability, and selectivity. Mixed matrix membranes (MMMs), which combine polymer matrices with inorganic or organic fillers, address these issues. In this study, MMM was fabricated by incorporating microcrystalline cellulose (MCC) with the polyvinylidene fluoride (PVDF) using non-solvent induced phase separation (NIPS) method. Scanning electron microscopy (SEM) revealed that the membranes have elongated finger-like pores and increases in size with higher MCC content. MMM3 (contain 5.0 wt.% MCC) had the highest porosity and mean pore radius of 55.74 % and 19.05 nm respectively. FTIR and XRD confirmed amorphous structure, and also showing the presence of the MCC and PVDF functional groups. MMMs are more hydrophilic than the pristine membrane, with the lowest water contact angle (84.23°) and high water flux (103.61 ± 8.06 Lm-2h-1) is observed in MMM3. The tensile strength of MMMs increased, whilst the elongation-at-break decreased with more MCC. The char yield was the lowest (72.1 %) in MMM3, showing good thermal properties. CO2 hydrations were measured using titration. All the MMMs showed improved CO2 hydration performance compared to pristine PVDF. This research demonstrates that adding MCC to PVDF membranes improves hydrophilicity and CO2 affinity, presenting a sustainable, and low-energy solution for CO2 capture and reduction.