Adsorption of Anionic Nanosheets from Their Dilute Colloidal Suspensions onto Gas-Liquid Interfaces with and without a Langmuir Film of Cationic Surfactant

摘要

The adsorption of [(Ca_2Nb_3 O_(10))~-]_n (CNO) polyanionic nanosheets from their dilute colloidal suspensions onto gas-liquid interfaces with and without a cationic [N(CH_3)_2(C_(18)H_(37))_2]~+ (DOA) surfactant film has been experimentally investigated. Our concern has been focused particularly on their dynamical aspects, which can be observed owing to the long specific time of the adsorption. The theoretical framework of the Langmuir adsorption model has enabled a quantitative analysis of the observed data, and that analysis has indicated that the presence of a positively charged Langmuir film enhances the ratio of the adsorption and desorption rate constants by a pproximately 30 times. Furthermore, the experimental results have shown that a “balanced” hybrid Langmuir film, in which both organic and inorganic constituents are densely packed, can be prepared.