Interfacial shear rheology measurements. Interfacial shear rheology was selected for the evaluation of interfacial shear mechanics. Interfacial rheological measurements were carried out on a Discovery Hydrid-Rheometer (DHR-3) from TA Instruments, using a Du Nouy Ring geometry and a Delrin trough with a circular channel. The Du Nouy ring has a diamond-shaped cross section that improves positioning at the interface between two liquids to measure interfacial rheological properties whilst minimizing viscous drag from upper and sub-phases. The ring has a radius of 10 mm and is made of a platinum-iridium wire of 400 μm thickness. The Derlin trough was filled with 4 mL of fluorinated oil (with or without surfactant). Using axial force monitoring, the ring was positioned at the surface of the fluorinated oil, and was then lowered by a further 200 μm to position the medial plane of the ring at the fluorinated phase interface. 4 mL of the PBS solution were then gently introduced to fully cover the fluorinated sub-phase. Time sweeps were performed at a frequency of 0.1 Hz and temperature of 25 o C, with a displacement of 1.0 10 -3 rad (strain of 1 %) to follow the self-assembly of the protein nanosheets at corresponding interfaces.