EFFECT OF DIFFUSIONAL LOSSES ON THE FORMATION OF MONOLAYERS OF SOLUBLE-PROTEINS AT AIR WATER INTERFACES WITH TRURNITS METHOD/

Monolayers of bovine serum albumin (BSA) were prepared with Trurnit's method; deposition of thin aqueous layers on an aqueous substrate foll owed by adsorption on the surface. The experiments demonstrated that a dsorption was irreversible, initially diffusion controlled as determin ed before, but also that diffusional effects toward the bulk were impo rtant. Three two-layer-diffusion and adsorption models were solved num erically to gain insight into these effects and determine the conditio ns at which Trurnit's method is reliable. The method is most reliable for irreversible diffusion-controlled adsorption. For reversible diffu sion-controlled adsorption the method can have significant error mostl y at very long adsorption times. For slower adsorption kinetics and re versible adsorption, the method is unreliable even at small adsorption times.