|Budget Amount *help
¥1,600,000 (Direct Cost : ¥1,600,000)
Fiscal Year 1990 : ¥300,000 (Direct Cost : ¥300,000)
Fiscal Year 1989 : ¥1,300,000 (Direct Cost : ¥1,300,000)
We measured lateral conductivity kappa_f (ohm-1)along the polar heads of black films formed from solutions of lysophosphatidylcholine in the presence of electrolyte. The measurements were performed in the range of electrolyte concentration from 10^<-4> to 10^<-1> M and temperature from 25 to 45ﾟC, using cylindrical films drawn between two coaxial, hollow, cylindrical Pt electrodes.
In the case of NaCl, kappa_f increases proportionally with bulk concentration of NaCl. On the other hand, at low CaCl_2 concentration, kappa_f is small up 'to about lmM, where kappa_f increases dramatically and then increases gradually with further increase in CaCl_2 concentration. It is observed that on increasing CaCl_2 concentration, at the same time the transitions of equilibrium thickness of films take place.
Further, activation energies E_f were obtained from Arrhenins PlOtS of kappa_f. In the case of CaCl_2, E_f's for both silver and common films are nearly equal to the activation energy E of bulk solution. For the Newton black films formed at low CaCl_2 concentration, E_f is about 2 - 3 times higher than E. On the other hand, for the Newton black films formed at high CaCl_2 concentration, E_f is close to tile activation energy for bulk solution.
We'll discuss the dependence kappa_f on the electrolyte concentration, by using the values of the film thickness, bulk conductivity and the activation energy of kappa_f.