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' detection cell, the oscillation frequencies were measured in various non-electrolyte solutions, and the frequency changes from those in pure water, Delta F, were plotted against the changes of root rho eta from those in 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 Delta 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 frequency 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 between Delta F and Delta root rho eta for electrolyte solutions was also examined.