Interface-Tailored Forces Fluffing Protein Fiber Membranes For High-Performance Filtration

Conventional electrospinning, along with a fiber accumulation mode parallel to the collector, results in 2D compact structures with limited performance. Fluffing the fiber membranes can enhance their functional per-formance, e.g., filtration performance (high filtration efficiency but lower airflow resistance), by means of enlarging both the pores and surface area. In this study, without additional instrumental design or any post-treatment, we report a quasi-3D and highly fluffy protein fiber membrane with high filtration performance by applying interface-tailored forces. Via the design of a cooperative collector for generating dual interfacial forces and the manipulation of the surface charges and polarities of protein by different surfactants, a competition between the interfacial forces is achieved. It is found that only with the least polarity and the most charges from protein can a strong repulsion force be generated. The protein fibers, being in-situ repulsed, deposit along with quasi-3D directions, leading to extremely fluffy structures. Compared with a compact protein fiber membrane, the properly fluffed protein fiber membrane exhibits reduced airflow resistance by 11.5 Pa while a higher removal efficiency is acquired. This work deepens the understanding of the interfacial impact on fiber deposition and provides an enlightening strategy to fabricating 3D fiber membranes.