Characterizing the infrared bands of aqueous soluble silicates.
A systematic study of the transition in silicate solutions from a solution containing a highly complex mixture of silicate species to one dominated by a single symmetric cubic octamer has been completed. Infrared and NMR results have been analyzed and compared with each other and literature values. The FT-IR band locations are dependent on many factors, particularly the dominant band near 1000 cm(-1). The analysis supports Dent Glasser's hypothesis that silica polymerization results from changes in distribution between the larger colloidal silica and intermediate sized anionic fraction rather than the continuous stepwise growth seen with organic polymerization. A constant value of silica monomer seen in all solutions independent of the complexity of the species or their distribution suggests equilibrium between the monomeric form and larger anions and polymers that is independent of their structure. No evidence is uncovered for specific silicate species dependent IR band assignments.
Falcone
James S
JS
West Chester University of Pennsylvania, Department of Chemistry, Schmucker Science Center South, West Chester, Pennsylvania 19382, USA. jfalcone@wcupa.edu
Bass
Jonathan L
JL
Krumrine
Paul H
PH
Brensinger
Karen
K
Schenk
Emily R
ER
D009682:Magnetic Resonance Spectroscopy / Q000592:standards; D012015:Reference Standards; D017640:Silicates / Q000737:chemistry*; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D014867:Water / Q000737:chemistry
D017640:Silicates; D014867:Water