Building bimodal structures by a wettability difference-driven strategy for high-performance protein air-filters

Area of Science:

• Materials Science
• Nanotechnology
• Biomaterials Engineering

Background:

• Air filters often face a trade-off between low airflow resistance and high filtration efficiency.
• Multi-jet electrospinning is a key technique for fabricating filter materials, but the influence of fiber interactions on morphology is often neglected.
• Developing advanced filtration materials from natural products is crucial for sustainable technology.

Purpose of the Study:

• To engineer a bimodal protein fabric with enhanced air filtration performance using a wettability difference-driven strategy.
• To investigate the effect of co-spinning proteins with varying wettability on fiber morphology and filtration characteristics.
• To explore the potential of natural proteins for creating high-performance air filters.

Main Methods:

• Co-spinning of zein and gelatin proteins with distinct wettability using a multi-jet electrospinning setup.
• Fabrication of control protein fabrics using single-jet electrospinning for comparison.
• Characterization of fiber diameter distribution using microscopy.
• Evaluation of filtration efficiency for particulate matter (PM2.5 and PM0.3) and airflow resistance.

Main Results:

• A bimodal fiber diameter distribution was spontaneously achieved by co-spinning zein and gelatin, with fiber diameters of 270 nm (gelatin) and 1.12 µm (zein).
• Pure protein fabrics exhibited unimodal fiber diameters (500-700 nm).
• The bimodal protein-blend fabric demonstrated exceptional removal efficiencies (99.67% for PM2.5, 98.80% for PM0.3) at ultra-low airflow resistance (38 Pa).
• Long-term performance showed sustained PM2.5 removal efficiency of 96.04% after filtering 1000 L of polluted air.

Conclusions:

• Wettability difference-driven co-spinning is an effective strategy for fabricating bimodal structures with superior air filtration properties.
• The developed bimodal protein fabric offers a promising natural alternative for high-performance air filtration with reduced airflow resistance.
• This study provides new insights into controlling fiber morphology in multi-jet electrospinning for advanced material design.