(401n) Highly Scalable and Efficient Honeycomb-like PVDF-PEI Hollow Fiber Membranes for Direct Air Capture

The escalating levels of atmospheric carbon dioxide (CO₂) necessitate the development of effective and efficient CO₂ capture technologies to mitigate climate change. This study explores the development and application of novel, scalable, and efficient polyethyleneimine (PEI)-functionalized polyvinylidene fluoride (PVDF) hollow fiber membranes for direct CO₂ capture. By integrating the high CO₂ affinity of PEI with the highly porous structural properties of PVDF, the developed hybrid PVDF-PEI hollow fiber membranes demonstrate enhanced CO₂ adsorption capacity under diluted CO₂ conditions. The CO₂ adsorption capacity was investigated under different conditions, revealing that the PVDF-PEI membrane with 6% of accessible amine loadings exhibited the highest adsorption capacity, reaching up to 0.5 mmol-CO₂/g-membrane. Four different adsorption kinetic models were analyzed, and the results indicated that the CO₂ adsorption rate is proportional to the number of accessible amine sites along the membrane matrix. The membrane's structural integrity and surface characteristics were examined using various techniques, confirming the successful and stable incorporation of PEI and the retention of the PVDF membrane’s framework. This study highlights the potential of scalable and efficient PVDF-PEI hollow fiber membranes as a promising solution for efficient CO₂ capture, contributing to the development of sustainable technologies for mitigating global warming.