Investigation of nitrobenzene liquid membrane oscillator containing benzyldimethyltetradecylammonium chloride

The oscillatory behaviour of a nitrobenzene liquid membrane oscillator containing benzyldimethyltetradecylammonium chloride was investigated in order to recognize the oscillation mechanism. The influence of temperature and electrode distances from the interfaces as well as the donor, membrane and acceptor phase composition on the changes of electric potential difference between aqueous phases was examined. The effect of the surfactant structure on the oscillation characteristics was discussed. It was shown that the appearance of oscillations requires the simultaneous presence of surfactant, picric acid and ethanol in the system. The mechanism of oscillations in this system should be similar as the one in an oscillator containing hexadecyltrimethylammonium bromide where oscillations of electric potential difference between the two aqueous phases are produced by sudden adsorption and desorption of the surfactant and the ionic pair: a surfactant-picric anion at the a/m interface. The diffusion fluxes of all these species in the vicinity of a/m interface also play an important role. They might couple, which leads to the nonlinear behaviour of the system. The oscillation curves obtained for the liquid membrane oscillator with benzyldimethyltetradecylammonium chloride and different taste substances were analyzed by the construction of the corresponding attractors in two-dimensional space using the time delay method. Each system has its own attractor differing in shape and surface. Therefore, these properties might be used for identifying an unknown taste substance present in the acceptor phase.