An Investigation on the Different Application and Techniques of Maximum Pressure Tensiometer |
Here, based on the theoretical analysis of results fortwo ionic surfactants, sodium dodecyl sulfate (SDS) anddodecyltrimethylammonium bromide (DTAB), we develop a new approach forquantitative interpretation of data from the maximum bubble pressure method. Agiven Tensiometer is characterized by an apparatus function, A(t), and by an apparatus constant. The former represents the timedependence of the bubble surface area, whereas the latter is expressed throughintegrals of A(t). The experiment indicates thatboth of them are independent of the surfactant type and concentration.Moreover, if a certain criterion is satisfied, the experimental results dependon the surface dilatation only through the apparatus constant. This makes thedata interpretation much easier. The knowledge of the apparatus constant givesa general time scale (universal surface age) that makes the results independentof the specific bubble pressure setup and produces dynamic surface tensioncurves that are universal characteristics of the investigated solutions. A newequation for data processing is proposed, which provides excellent fits of thedynamic surface tension. In the case of micellar solutions, the data analysisenables one to identify the kinetic regime of adsorption (among four possibleregimes). For the investigated surfactant solutions, the diffusion regime “BC”was identified, for which the fast micellar process is equilibrated, whereasthe slow micellar process is negligible. Upgraded with the developed approachfor quantitative data interpretation, the bubble-pressure tensiometry could bea useful tool for a detailed analysis of the adsorption processes in morecomplex systems.