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The influence of NaCl on interfacial properties is studied by measuring foamibility, foam stability and equilibrium. The surfactants chosen in these experiments are sodium dodecyl sulfate (SDS), Ethanol, n-propanol, 1-buthanol and Aniline.
Symbol of foam stability is considered as the time that the height of column becomes zero.It seems that the relation between foam stability and NaCl concentration for all alcohols is the same. When the concentration of surfactants increases the foam stability, at constant NaCl concentration increases and with increasing NaCl at constant concentration of surfactants, this result is observed. For SDS the time stability is the maximum value and this is because SDS is an anionic and strong surfactant. The mixture of SDS and NaCl, causes the more stability.