Structure of aqueous sodium metaborate solutions: X-ray diffraction study

Abstract

A structural analysis of aqueous sodium metaborate solutions (NaBo2 · nH2O, n = 10, 15, 20) at 298 ± 0.5 K by a rapid liquid θ-θ X-ray diffractometry with a highly effective X’celerator detector is reported in present paper. The radial distribution functions (RDF) and theoretical partial radial distribution functions for B-O, O-O, Na-O, Na-B, and Na-Na atom pairs were obtained from precisely diffraction data processing. Structure of aqueous sodium metaborate solutions was given through model calculation and described in three different items: hydrated sodium ion, hydrated metaborate ion and ion association. Effects of concentration on the structure of the solutions were discussed in detail. The mechanisms of ion aggregation and the formation of crystal nuclei in the solution are proposed. The results show that a clear picture of the structure of aqueous sodium metaborate solution has been acquired.