Air / Liquid Interface Expansion Rheology And Bubble Nature Of The Research

In this paper we mainly discussed Block Pluronic Surfactant (L61 and F68) foam properties by the methods of Dynamic Surface Tension, Foaming and Interfacial Rheology. We studied the effect of concentration and salinity on foam properties and the foam properties by mixing different Block Pluronic surfactants. In addition, we also studied the defoaming efficiency of Block Pluronic surfactants on foam initiated by Bovine Serum Albumin (BSA). Moreover, we investigated the properties of interfacial rheology of one system as foam circulating system compounded of AOS and BS. Except that, we also measured the CMC and adsorption Amount by Wilhelmy Balanced surface tension and the Dynamic Surface Tension by Maximum Bubble Pressure, by which we could calculated the surface elasticity, and then gained diffuse coefficients from surface to solution combined with balanced surface tension. The results showed that surface elasticity correlated with foam stability closely, only the surface elasticity being in limited range, the foam could be stable, when out of this scope, foam became more unstable. The diffuse coefficient could be responsible with adsorption and diffusion of surfactant molecules. Combined with these two kinds of data, we can explain the stabilized mechanism of foam solution. The results of Interfacial Rheology showed that dilational modulus varied with frequency and the concentrations of Block Pluronic Surfactant were correlated with the foaming results to some extent. The conclusions were as following:1. The CMC of F68 was about 70g/L, while in the solution with 0.5-4.0% NaCl, the measuring CMC was about 50 g/L, 40 g/L, 30 g/L and 5 g/L respectively, the cloud point of L61 was lower and its CMC was higher than Ig/L. While for the system of F68(60g/L)+L61(0.06g/L), F68 and L61 could form mixing micelle, and its CMC was about 7g/L. increasing the concentration of surfactants, the adsorption amount increased and effective diffuse coefficient would increase slowly. When its concentration was lowed than CMC, the adding of salts would reduce the adsorption amount with effective diffuse coefficient increased, though the adding of L61 had reduced the adsorption amount, which was close to that of L61 existing solely. The diffuse coefficient of F68/L61 system is an order lower than F68 existing solely, and the used expressions were not applicable in this...