Hierarchically porous polyvinyl alcohol sodium lignosulfonate aerogel fiber aggregates for proteins adsorption and separation

The trade-off between convective mass transport and binding capacity remains a critical challenge in designing stationary phases for high-throughput biopharmaceutical purification. Herein, we report a facile and scalable fabrication strategy to construct hierarchically porous sodium lignosulfonate/polyvinyl alcohol composite aerogel fibers (LS/PVA-AFs) by integrating centrifugal wet-spinning with non-solvent induced phase separation. In this composite architecture, PVA acts as a mechanically stable skeleton, while LS provides a high density of surface-accessible sulfonate groups (-SO 3 ) for cation-exchange adsorption. Subsequent crosslinking with epichlorohydrin stabilizes the three-dimensional network, minimizing swelling and ensuring structural integrity. Under optimized conditions (10 wt% PVA and 15 wt% LS), the resulting LS/PVA-AFs exhibit a highly porous skeleton, excellent hydrophilicity, and a strongly negative surface charge. Using lysozyme as a model basic protein, the fibers achieved a static adsorption capacity of 1726.34 mg/g, with over 95% capacity retention after ten regenerative cycles. When packed into a chromatography column, the LS/PVA-AFs demonstrate a high hydraulic flux of 77.65 L/h at 0.5 bar and exhibited a high dynamic binding capacity of 655.41 mg/g at 10% breakthrough. This work provides a robust and green platform for bridging the gap between high-flux throughput and high-capacity binding in next-generation downstream bioprocessing.