Tensiometry isotherm

The cellulose derivatives E4M, E50LV, and F4M have shown different behavior at the air-water interface. E4M displayed the highest adsorption efficiency and surface activity, as could be determined from tensiometry and ir-A isotherms. E4M was found to adsorb fastest at the interface. The high hysteresis shown by E4M implies that it forms monolayers where molecules can be more compacted after compression and yet keep the acquired spatial conformation. 

The miceUization of binary surfactant solutions is studied by the method of tensiometry at the variation of the fraction of ionic surfactant within the range 0-1.0. The quantitative treatment of the surface tension isotherms within the framework of the phase separation modeP showed that the values of the interaction parameter p in these systems lay within the range (-0.85)-(-. 6). This indicates that in these systems synergetic behaviour occurs, i.e. the mixed aggregates are formed. The surface potential is calculated for all the systems. A decrease in the potential is shown to occur with a decrease in In... 

Abstract Based on surface/interfacial tension isotherms measured for the homologous series of alkyl trimethyl ammonium bromides (CnTAB) using the drop profile analysis tensiometry the adsorption behavior at three different liquid-fluid interfaces is discussed solution/air, solution/hexane vapor and solution/hexane bulk liquid. The adsorption behavior can be described by different models. In the presence of hexane molecules (as a bulk liquid or as vapor in the air phase) the adsorption of the CnTAB molecules can be best described by a competitive adsorption with hexane molecules. This competitive thermodynamic model can be applied successfully to all three interfaces. 

FIG. 5 Adsorption isotherms of fluorinated surfactants obtained by neutron reflectivity and tensiometry measurements (a) di-CF4, (b) di-HCF4, and (c) di-FICF4GLU. Example error bars are shown for some points. (From Ref. 44.)... 

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