title: Ion exchange at a surface monolayer.
abstract: Total reflection total conversion electron yield X-ray absorption fine structure is applied to the evaluation of ion exchange occurring at the surface monolayer of two-tailed ammonium ions. X-ray absorption measurements at a Br K-edge allow us to detect ion-exchange equilibria between Br- and Cl- added in a subphase. The ion-exchange selectivity of Br- over Cl- basically increases as the monolayer is compressed, indicating that Cl- is selectively squeezed out by compression because of its larger hydrated ionic radius.
authors.forename: Makoto
authors.initials: M
authors.lastname: Harada
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Okada
mesh_terms: D000042:Absorption; D001965:Bromides / Q000737:chemistry*; D002712:Chlorides / Q000737:chemistry*; D007474:Ion Exchange; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013499:Surface Properties; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D001965:Bromides; D002712:Chlorides; D000644:Quaternary Ammonium Compounds