Positronium dynamics in aqueous solutions of ionic surfactants Original Research Article

The dynamics of positron-electron correlated pairs (positronium, Ps) in aqueous solutions of sodium dodecylsulfate and dodecyltrimethylammonium bromide at different concentrations was investigated by means of lifetime spectroscopy at room temperature. The results were framed within a simple trapping model; separate magnetic quenching experiments supplied information on the site of Ps trapped inside the micelles. From the lifetime data an estimation of the surface tension inside the micelle was obtained.