INFLUENCE OF COLLOIDAL SUBPHASE PH ON THE DEPOSITION OF MULTILAYER LANGMUIR-BLODGETT-FILMS OF GOLD CLUSTERS

Negatively charged carboxylic acid derivatized gold colloidal particle s have been immobilized at the air/water interface using positively ch arged fatty amine Langmuir monolayers. The degree of cluster incorpora tion into the Langmuir monolayer has been systematically controlled by varying the charge on the surface amine through the colloidal subphas e pH. This affects the quality of multilayer gold cluster films transf erred to different substrates by the Langmuir-Blodgett method. Pressur e-area isotherms were measured to follow cluster adsorption at the air /water interface while characterization of the multilayer films was un dertaken using quartz crystal microgravimetry, UV-VIS spectroscopy, co ntact angle measurements, transmission electron microscopy, ellipsomet ry and X-ray photoelectron spectroscopy. Incorporation of clusters int o organic matrices in the manner outlined is promising for the synthes is of superlattice structures, mixed cluster systems, etc., which cann ot be realized by current experimental methods.