β-Casein Bilayer Adsorption at the Solution/Air Interface: Experimental Evidences and Theoretical Description

Studies of the rate of water evaporation through adsorption layers using drop shape analysis tensiometry

“…6 with reproduced data from [12]). In this concentration range the equilibrium adsorption of the protein and the adsorption layer thickness become essentially higher (by approximately a factor of 2 in the concentration range 0.2-100 µmol/L [12,13]). This phenomenon can be attributed either to the formation of a second adsorption layer or to the increase in the protein adsorption layer thickness due to condensation [7,13].…”

“…In this concentration range the equilibrium adsorption of the protein and the adsorption layer thickness become essentially higher (by approximately a factor of 2 in the concentration range 0.2-100 µmol/L [12,13]). This phenomenon can be attributed either to the formation of a second adsorption layer or to the increase in the protein adsorption layer thickness due to condensation [7,13]. According to the theoretical model [7], both phenomena do not affect significantly the surface pressure, but lead to an essential increase in the adsorbed layer thickness.…”

Ellipsometric study of nonionic polymer solutions

“…Therefore, we performed an ellipsometric study of PVP and PEG solutions using the modern version of this experimental technique that allows accurate measurements of the adsorption layer parameters [18]. Ellipsometry was used rather frequently for investigations of adsorption films of natural polymers [19][20][21] and spread films of synthetic polymers [22][23][24]. Applications to nonionic polymer solutions were more seldom [25].…”

Modeling two-rate adsorption kinetics: Two-site, two-species, bilayer and rearrangement adsorption processes

“…This model can be used to explain the adsorption of aromatic hydrocarbons on silica gel [24], synthetic amphiphiles on polystyrene microspheres [25], organic dyes on liposomes [26], proteins on air/water or oil/water interfaces [27] or adsorption of alkylammonium surfactants at the solid/water interface [28].…”

“…This is generally not explained by any of the 'traditional' isotherms listed above, and so a range of new models have arisen in the last few decades in an attempt to provide a physical rationalization for the behavior seen [6][7][8][9][10][11][12][13]. Typically, the two-rate adsorption behavior can be a result of four possibilities (or a combination of them) -two-sites with different energies [14][15][16][17][18], two species with different adsorption rate constants (or diffusion coefficients) [19], rearrangement of adsorbed molecules on the surface [20][21][22][23] or bilayer adsorption [24][25][26][27][28]. Such tworate adsorption processes have been seen for surfactants, proteins, small organic molecules, etc.…”