Preparation and Characterization of Langmuir-Blodgett Films of Wheel-Shaped Cu-20 Tungstophosphate and DODA by Two Different Strategies

A novel surfactant-encapsulated organic-inorganic hybrid compound (DODA)(24)Li[Cu20Cl(OH)(24)(P8W48O184)] (DODA-Cu20) has been prepared from the wheel-shaped tungstophosphate salt K12Li13[Cu20Cl(OH)(24)(H2O)(12)(P8W48O184)]center dot 22H(2)O(CU20) and dimethyldioctadecylammonium bromide (DODA), and it has been characterized by elemental analysis (EA), thermogravimetric analysis (TGA), H-1 NMR, Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD) measurements. Monolayer and multilayer films of DODA-Cu20 were fabricated on different substrates by the Langmuir-Blodgett (LB) technique using H2O as the subphase. Another type of organic-inorganic hybrid film, DODA/Cu20, was also deposited on the same substrates its used for the film containing DODA-Cu20 under the same conditions by the LB technique using a Cu20 aqueous solution its the subphase and DODA its the cationic amphiphile for comparison. Both thus-prepared organic-inorganic hybrid films were characterized by UV-vis spectroscopy, XRD, transmission and polarized FT-IR spectroscopy, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). the results indicate that stable monolayers at the air-water interface for DODA-Cu20 and at the air-Cu20 Solution interface for DODA can be formed and that two LB films containing DODA-Cu20 and DODA/Cu20 constructed by two different methods both exhibit well-ordered lamellar structures. It is proposed that Cu20 exhibits different packing modes in the two LB films depending on the deposition strategy used.