title: Optimizing a flow-through X-ray transmission cell for studies of temporal and spatial variations of ion distributions at mineral-water interfaces.
abstract: The optimization of an X-ray transmission-cell design for high-resolution X-ray reflectivity measurements of the kinetics and thermodynamics of reactions at mineral-solution interfaces is presented. The transmission cell is equipped with a liquid flow system consisting of a pair of automated syringe pumps whose relative flow rates control the composition of a solution injected into the cell with ∼1% precision. The reflectivity measurements from the muscovite-(001)-solution interface at photon energies of 15-16.5 keV show that the cell is useful for probing interfacial ion adsorption-desorption experiments at a time scale of several seconds or slower. The time resolution is achieved with a small-volume (∼0.22 ml) reaction chamber to facilitate fast solution exchange. Additional reductions in reaction chamber volume will improve both the data quality by reducing X-ray absorption through the solution and the time resolution by increasing the solution exchange rate in the cell.
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA. sslee@anl.gov
authors.forename: Sang Soo
authors.initials: SS
authors.lastname: Lee
authors.forename: Paul
authors.initials: P
authors.lastname: Fenter
authors.forename: Changyong
authors.initials: C
authors.lastname: Park