A Study of Wheat Storage Protein Monolayers by Faraday Wave Damping

Properties of monolayers formed by wheat storage proteins (WSP) at an air/water interface were investigated by measuring the monolayers’ effects on the damping of standing waves excited by vertical oscillations of a circular cylinder of water. A small concentration of a WSP monolayer increased wave-damping rates by a factor of 10, which is ~50% higher than predicted by published models. The damping rate also showed an unpredicted dependence on small changes in frequency. Cross-linking among molecules did not affect the wave-damping rates as a function of time. The WSP monolayer wet glass more effectively with increasing concentration. Damping rates were independent of whether the monolayer was spread from the solid or solution fraction.