#1 Solid Liquid
A Bruker Tensor 27 Fourier-transform infrared spectrometer has been adapted for the characterization of solid-liquid interfaces. The infrared beam exiting the interferometer is directed through a variable-angle polarizer towards a cell especially designed for the characterization of molecules adsorbed on surfaces from a liquid phase in a single reflection-absorption (RAIRS) mode. The light is focused through a calcium fluoride window onto the flat substrate, which is immersed in the reacting solution, and the reflected beam is picked up after exiting the other side of the same prism by a set of mirrors and focused onto a MCT detector. The cell is equipped with a counter electrode in order to allow for surface cleaning by an electrochemical treatment. The liquid in the cell can be flowed through a volume above the surface, a film of a thickness that can be set by a micrometer. Gases can be bubbled in for purging as well, and electrochemical studies can be carried out by using a third reference electrode. Experiment on powder samples can be carried out by suspending the sample in the liquid solution.
Techniques: RAIRS on solid-liquid interfaces