title: Auto-oscillation of surface tension: effect of pH on fatty acid systems.
abstract: Spontaneous nonlinear oscillations of surface tension produced by transfer of either octanoic or nonanoic acids from a droplet situated in the bulk water to the air/water interface are studied experimentally. It is shown that the oscillation amplitude decreases significantly with the increase of pH of aqueous phase. At pH > 6.5, detectable oscillations for the two fatty acids studied do not exist. The results are discussed in terms of the mechanism proposed recently for spontaneous oscillations produced by transfer of nonionic surfactants.
authors: Institute of Biocolloid Chemistry, 03142 Kyiv, Ukraine.
authors: N M
authors: NM
authors: Kovalchuk
authors: D
authors: D
authors: Vollhardt
mesh_terms: D000388:Air; D002210:Caprylates / Q000737:chemistry; D005227:Fatty Acids / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D017711:Nonlinear Dynamics; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D002210:Caprylates; D005227:Fatty Acids; D013501:Surface-Active Agents; D014867:Water; C031492:octanoic acid