Dielectric relaxation of dilute aqueous NaOH, NaAl(OH)4 and NaB(OH)4
*Subscription may be required
The complex dielectric permittivity of aqueous NaOH (c ≤ 2 M) and of dilute (≤0.6 M) NaAl(OH)4 and NaB(OH)4 solutions in NaOH ([Na] = 1 M) at 25°C has been determined in the frequency range 0.2 ≤ v/GHz ≤ 20. All spectra could be represented by a single Cole-Cole relaxation time distribution attributed to the cooperative relaxation of the solvent. The concentration dependence of the effective hydration number of OH- has been determined. For aluminate and borate solutions the deduced parameters: effective conductivity Ke, static permittivity ε, relaxation time τ, and distribution parameter a suggest a 1:1 replacement of hydroxide by aluminate and borate, accompanied by a release of bound water. The lack of an ion-pair relaxation process despite notable ion association suggests that rapid proton exchange is important not only for the dynamics of OH- but also for Al(OH)4- and B(OH)4-.
|Publication Type:||Journal Article|
|Murdoch Affiliation:||School of Chemical and Mathematical Science|
|Publisher:||American Chemical Society|
|Copyright:||© Copyright 1999 by the American Chemical Society.|
|Item Control Page|