- Hoek, Harmen;
- Gerber, Timm;
- Richter, Clemens;
- Dupuy, Rémi;
- Rapf, Rebecca;
- Oertel, Holger;
- Buttersack, Tillmann;
- Karslıoğlu, Osman;
- Goodacre, Dana;
- Gericke, Sabrina;
- Buechner, Christin;
- Rude, Bruce;
- Mugele, Frieder;
- Bluhm, Hendrik;
- Wilson, Kevin;
- Trotochaud, Lena;
- Blum, Monika
We present a combined Langmuir-Pockels trough and ambient pressure X-ray photoelectron spectroscopy (APXPS) study of the compression of stearic acid surfactant layers on neat water. Changes in the packing density of the molecules are directly determined from C 1s and O 1s APXPS data. The experimental data are fit with a 2D model for the stearic acid coverage. Based on the results of these proof-of-principle experiments, we discuss the remaining challenges that need to be overcome for future investigations of the role of surfactants in heterogeneous chemical reactions at liquid-vapor interfaces in combined Langmuir-Pockels trough and APXPS measurements.