Effect of silicate ratio on the distribution of silicate and aluminosilicate anions in TPA aluminosilicate solutions

Journal Article · Thu May 30 00:00:00 EDT 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100164a060· OSTI ID:5975769

Mortlock, R F; Bell, A T; Chakraborty, A K; Radke, C J ^[1]

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1. Lawrence Berkeley Lab., CA (United States)

{sup 29}Si and {sup 27}Al spectroscopies were used to characterize dilute, highly alkaline tetrapropylammonium (TPA) aluminosilicate solutions. The solution compositions ranged from 0.1 to 2 mol % SiO{sub 2}, silicate ratios (R = (SiO{sub 2})/((TPA){sub 2}O)) from 0.05 to 1, and Si/Al molar ratios from 0.25 to 5. {sup 29}Si NMR resonances were observed for Al incorporation into the dimer, linear trimer, cyclic trimer, branched cyclic trimer, double three-membered ring (D3R), and double four-membered ring (D4R) anions. In aluminosilicate solutions with 2 mol % SiO{sub 2}, silicate ratios of less than 1.5 lead to the stabilization of D3R(1Al) anions. The addition of DMSO to TPA aluminosilicate solutions provides the solutions with a high concentration of D3R(1Al) and D4R(1Al) anions. Semiempirical quantum mechanical calculations were performed to calculate the partial charges on Si atoms in silicate and aluminosilicate anionic structures. A correlation between the Si atom partial charge and its experimentally observed chemical shift assists in the assignment of {sup 29}Si NMR peaks due to soluble aluminosilicates.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5975769
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:11; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALUMINIUM COMPOUNDS
ALUMINIUM SILICATES
AMINES
AMMONIUM COMPOUNDS
ANIONS
CHARGE STATES
CHARGED PARTICLES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CHEMICAL SHIFT
DATA
DISPERSIONS
EVEN-ODD NUCLEI
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
IONS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MATERIALS
MATHEMATICAL MODELS
MINERALS
MIXTURES
MOLECULAR STRUCTURE
NMR SPECTRA
NUCLEAR MAGNETIC RESONANCE
NUCLEI
NUMERICAL DATA
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
QUANTITY RATIO
QUATERNARY COMPOUNDS
RESONANCE
SILICATE MINERALS
SILICATES
SILICON 29
SILICON COMPOUNDS
SILICON ISOTOPES
SOLUTIONS
SPECTRA
STABLE ISOTOPES
SYNTHESIS
THEORETICAL DATA
ZEOLITES