Characterization of Liquid Surfaces Using the Advanced Surface-Horizontal X-ray Reflectometer at SPring-8

Abstract

X-ray reflectivity measurements of liquid surfaces were demonstrated using a recently developed liquid interface reflectometer at SPring-8. The reflectometer has two features superior to other surface-horizontal spectrometers currently available at synchrotron facilities around the world : achieving quick measurements and investigating the surface structure for both vertical and horizontal directions simultaneously. We demonstrated X-ray reflectivity measurements of an aqueous ionic liquid, and time-resolved measurements for the adsorption process of a globular protein lysozyme on a water/air interface. X-ray specular and off-specular reflection was also investigated to analyze the out-of-plane and in-plane structures of lysozyme adsorbed at an air/water interface in the presence of a salt.