Adsorption kinetics of nonanediol and nonane dicarbonic acid at the air/water interface

Kinetic study of adsorption of some biocompounds at the oil/water interface

“…In our cases it is found that experimental data cannot be understood by a simple diffusion and one must drop the boundary condition of local equilibrium [6,7], and replace it by Langmuir kinetic approach [8,42] of the following form:…”

“…If the increase of adsorption is proportional to the decrease of interfacial tension, Eq. (5) may be written as: ∆σ = ∆σ 0 e −kt (6) or in a logarithmic form:…”

“…Generally, the adsorption of surfactant molecules from a solution to a liquid/gas [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] or to a liquid/liquid interface [1,5,[16][17][18][19][20][21][22][23][24] occurs in two steps. Surfactant molecules are first transported from the bulk to the subsurface by diffusion (the subsurface is a liquid layer just below the interface, belonging still to the bulk).…”

“…the adsorption is barrier-controlled). Several theoretical models have been developed for both processes, as well as for mixed adsorption mechanisms in which both steps are considered [1][2][3][4][5][6].…”

“…Further, the adsorption kinetics of some aliphatic carboxylic acids and aliphatic alcohols [6][7][8][9], like 1, 9 nonane dicarboxylic acid and 1, 9 nonane diol [6], was studied at the air/water interface and described by Langmuir kinetics, considering the adsorption and desorption rate constants. Another example is related to the adsorption of some salts of fatty acids, like sodium laurate [10,11,13], sodium myristate [10,11], and sodium oleate [14], from aqueous solutions to the air/water interface, which was analyzed by means of diffusion controlled kinetics.…”