Abstract
The effects of cations on the adsorption of Ca 2+ to stearic acid monolayers was investigated by the radiotracer method. The addition of either Na + or K +, once the monolayer had formed in the presence of Ca 2+, caused by desorption of Ca 2- from the monolayer. The rate of desorption of Ca 2+ brought about by K + was greater than that by Na +; whereas, the equilibrium adsorptions were almost the same. The free energy of the exchange reaction was the same for both ions. Mg 2+, Ba 2+ and Sr 2+ all bind to the monolayer to the same extent as Ca 2+ but to a considerably lesser extent than the transition metal ions. The difference interfacial effect of Na − and K +, which may be related to the time needed to desolvate the ions prior to interaction, may in part account for the K + selectivity of cellular membranes.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
