In Situ Characterization of the Initial Effect of Water on Molecular Interactions at the Interface of Organic/Inorganic Hybrid Systems.
Probing initial interactions at the interface of hybrid systems under humid conditions has the potential to reveal the local chemical environment at solid/solid interfaces under real-world, technologically relevant conditions. Here, we show that ambient pressure X-ray photoelectron spectroscopy (APXPS) with a conventional X-ray source can be used to study the effects of water exposure on the interaction of a nanometer-thin polyacrylic acid (PAA) layer with a native aluminum oxide surface. The formation of a carboxylate ionic bond at the interface is characterized both with APXPS and in situ attenuated total reflectance Fourier transform infrared spectroscopy in the Kretschmann geometry (ATR-FTIR Kretschmann). When water is dosed in the APXPS chamber up to 5 Torr (~28% relative humidity), an increase in the amount of ionic bonds at the interface is observed. To confirm our APXPS interpretation, complementary ATR-FTIR Kretschmann experiments on a similar model system, which is exposed to an aqueous electrolyte, are conducted. These spectra demonstrate that water leads to an increased wet adhesion through increased ionic bond formation.
Department of Materials and Chemistry, Research Group Electrochemical and Surface Engineering (SURF), Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.|Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States of America.
Sven
S
Pletincx
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States of America.
Lena
L
Trotochaud
Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD, Delft, The Netherlands.
Laura-Lynn
LL
Fockaert
Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD, Delft, The Netherlands.
Johannes M C
JM
Mol
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States of America.
Ashley R
AR
Head
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States of America.
Osman
O
Karslıoğlu
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States of America.
Hendrik
H
Bluhm
Department of Materials and Chemistry, Research Group Electrochemical and Surface Engineering (SURF), Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.
Herman
H
Terryn
Department of Materials and Chemistry, Research Group Electrochemical and Surface Engineering (SURF), Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.
Tom
T
Hauffman