Investigating liquid surfaces down to the nanometer scale using grazing incidence X-ray scattering

Grazing incidence X-ray surface scattering has been used to investigate liquid surfaces down to the molecular scale. The free surface of water is well described by the capillary wave model (〈z(q)z(−q)〉∝q−2 spectrum) up to wave vectors >108m−1. At larger wave vectors near-surface acoustic waves must be taken into account. When the interface is bounded by a surfactant monolayer, it exhibits a bending stiffness and the bending rigidity modulus can …