title: Kinetics and mechanisms of monolayer interactions. III: models to explain time-dependent effects of injected cetrimonium bromide.
abstract: Two kinetic models are derived to explain the time-dependent effects of cetrimonium ions injected beneath an air-aqueous solution interface without any previously adsorbed or spread monolayer at different ionic strengths. The data show excellent fit and consistency with a nulticompartmental kinetic model which postulates a barrier or intermediate compartment between the ionic surfactant in the subphase and the sites on the surface. Such a barrier inhibits free diffusion of the surfactant from the bulk of the solution to these sites. The experimental data are not inconsistent with a model that postulates a time-dependent binding process and the absence of a diffusion-limiting subinterface since, within the limits of the error, the derived rate constants conform to the model prediction that they should be proportional to the surfactant-ion concentration.
mesh_terms: D000327:Adsorption; D000388:Air; D002593:Cetrimonium Compounds; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004058:Diffusion; D007700:Kinetics; D008567:Membranes, Artificial; D008956:Models, Chemical; D011189:Potassium Chloride; D000644:Quaternary Ammonium Compounds; D012965:Sodium Chloride; D013499:Surface Properties; D013500:Surface Tension; D014867:Water
chemical_list: D002593:Cetrimonium Compounds; D008567:Membranes, Artificial; D000644:Quaternary Ammonium Compounds; D014867:Water; D012965:Sodium Chloride; D011189:Potassium Chloride