Interfacial dilational behaviour of adsorbed β-lactoglobulin layers at the different fluid interfaces

Adsorption kinetics and dilatational rheological studies for the soluble and anchored forms of alkaline phosphatase at the air/water interface

“…This frequency range corresponds to relaxation times characteristic for different proteins 33,34 and is associated to rearrangement processes. As the obtained results show the same tendency, the frequency of 0.841 Hz and relative area variation of 5.5% (corresponding to the mechanical amplitude of 0.1 mm of the piezo system) were arbitrarily chosen to compare the data for the two proteins and for the non-ionic surfactant.…”

“…31,[38][39][40][41] For instance, β-lactoglobulin (M r 18.4 kDa) shows an average elasticity of 26.04 mN m -1 for a frequency of 0.0125Hz, at a concentration around 1x10 -7 mol L -1 . 33 Nevertheless, Benjamins et al 38 have already pointed out that the interfacial pressure rather than the bulk concentration is the most relevant parameter to compare the moduli. Thus, the value of 17.3 mN m -1 obtained for BSA, measured at a surface pressure of 56.2 mN m -1 , should be compared to the elasticity obtained for other globular proteins at the same surface pressure.…”

Interfacial dilational properties of tri-substituted alkyl benzene sulfonates at air/water and decane/water interfaces

“…This is because the hydrophobic chains of the adsorbed surfactant can penetrate into the oil phase, reducing the van der Waals interaction [44,45].…”

Tensiometry and dilational rheology of mixed β-lactoglobulin/ionic surfactant adsorption layers at water/air and water/hexane interfaces

“…This fact is attributed to the stronger cohesive interaction between the organic molecules and the protein's hydrophobic segments which leads to penetration of such segments into the oil phase thus changing the conformation of the protein in the adsorbed state compared to that at the W/A surface. A consequence of that is the attenuation of the intermolecular interaction within the interface which in turn results in lower values of the surface shear [5] and dilational [2][3][4][5][6][7][8][9] moduli for water/oil interface. Lucassen-Reynders et al proposed a relation between the dilational visco-elasticity modulus |E| and the interaction parameter H S in the equation of state for protein adsorption layers as both parameters diminish with decreasing the clean-interface tension c 0 bringing evidence that c 0 is an essential parameter in the visco-elasticity modulus [4,6].…”

“…Concerning the influence of the hydrophobic phase, the adsorption is more intensive at the water/oil interface compared to the water/air (W/ A) surface leading to smaller molar areas [1][2][3][4][5][6][7][8]. This fact is attributed to the stronger cohesive interaction between the organic molecules and the protein's hydrophobic segments which leads to penetration of such segments into the oil phase thus changing the conformation of the protein in the adsorbed state compared to that at the W/A surface.…”