Bicontinuous aerogels constructed with protein fibrils: A template for multiscale biomaterial customization

This study elucidates the structural regulation of whey protein fibrils (WPF) via shear modification, revealing how shear rates govern their hierarchical organization. Shear forces induce a rheological shift from elastic gels (tanδ < 1) to viscoelastic states (tanδ > 1), with particle size reduced to ~ 273 nm at 20,000 rpm. Molecularly, X-ray diffraction reveals that shear compacts form Cross-β sheets at 9.1 Å, thereby enhancing structural density. Mesoscopically, controlled shear rates (5,000–10,000 rpm) enable tunable porosity in bicontinuous emulsions. Lower rates (5,000 rpm) yield uniform, small pores, while higher rates (10,000 rpm) enlarge pores while maintaining connectivity. This approach produces aerogels with multiscale porosity. Notably, WPF-5 aerogels—characterized by dense microporous networks—exhibit a 4,512% increase in soybean oil adsorption, highlighting their potential for biomaterials. By integrating microscopic, mesoscopic, and molecular insights, this work provides a framework for precision-engineering multiscale protein-based materials, bridging fundamental science and functional applications.