Adsorption of water to the metal/polymer interface studied by neutron and X-ray reflectivity.

摘要

Neutron reflectivity is among the few techniques able to probe a buried interface. Through the use of isotopic labeling, complicated interface structures may be determined with a resolution on the order of 5 (angstrom). However, for highly complex thin film and interface structures, it is often necessary to perform complementary experiments to reduce the number of unknown variables, and thus enable an unambiguous interpretation of the neutron reflectivity. To this end, the authors have combined X-ray and neutron reflectivity to study changes in a metal/polymer interface (molybdenum/polyurethane, hereafter Mo/PU) upon exposure to a humid environment. In particular, the authors have tracked the adsorption of moisture to the interface and variations in the density of the interphase. This information was obtained as a function of the concentration of a silane coupling agent added to the bulk of the PU. Adhesion of the Mo/PU interface is important to programs in the DOE complex. This paper reports the first results of this study.