Adsorption properties of polyelectrolytes in ultrathin multilayer assemblies: Investigations using the quartz crystal microbalance (QCM) technique

The in situ processes of alternate polyelectrolyte and dye self-assembly processes in ultrathin films was investigated using quartz crystal microbalance techniques. The time dependence of the frequency change showed a rapid initial decrease in frequency, followed by a less steep behavior. It was assumed that the adsorption rate is proportional to the polymer solution concentration and to the number of remaining unbound sites. The equation ln{(F-F∞)/(F0-F∞)} = -kt, was obtained, where t = time, F = the frequency at t, F0 = the initial frequency, F∞ = the saturation frequency, and k = the pseudo-first-order rate constant. The measured data were fitted with the equation and the τ values for different pairs were calculated.