NEW DETECTION CELL FOR PIEZOELECTRIC QUARTZ CRYSTALS - FREQUENCY CHANGES STRICTLY FOLLOW BRUCKENSTEIN AND SHAYS EQUATION IN VERY DILUTE NONELECTROLYTE AQUEOUS-SOLUTIONS

Using a newly designed detection cell called a 'loading-free' detectio n cell, the oscillation frequencies were measured in various non-elect rolyte solutions, and the frequency changes from those in pure water, Delta F, were plotted against the changes of root rho eta from those i n pure water, Delta root rho eta, where rho and eta, respectively, are the density and viscosity of the solution. For very dilute solutions of various non-electrolytes, the relationship between Delta F and Delt a root rho eta exactly follows Bruckenstein and Shays's equation [F = -2.26 X 10(-6)nF(b)(3/2) root rho eta, where F-b is the basic frequenc y of the crystal and n the number of surfaces exposed to the solution (n = 1 or 2)]. The rho eta values at which the data started to deviate from the equation depended on the solutes used. The relationship betw een Delta F and Delta root rho eta for electrolyte solutions was also examined.