NMR investigations of tetrapropylammonium aluminosilicate and borosilicate solutions

Journal Article · Wed Jan 09 23:00:00 EST 1991 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100154a067· OSTI ID:5852015

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

---

1. Univ. of California, Berkeley (USA)

{sup 29}Si, {sup 27}Al, and {sup 11}B NMR spectroscopies were used to characterize dilute, highly alkaline tetrapropylammonium (TPA) aluminosilicate and borosilicate solutions. The compositions of the solutions range from 0.1 to 2 mol % SiO{sub 2}, silicate ratios (R = (SiO{sub 2})/(M{sub 2}O); M{sup +} = TPA{sup +}) from 0.1 to 2, and Si/Al or Si/B molar ratios from 0.25 to 10. {sup 29}Si and {sup 27}Al NMR spectra provide evidence for the formation of aluminosilicate anions. Si is observed with Q{sub 1}(A1Al), Q{sub 2{minus}Delta}(1Al), Q{sub 2}(1Al) + Q{sub 3{Delta}}(1Al), and Q{sub 3}(1Al) connectivity. Several new {sup 29}Si NMR peaks are assigned to specific aluminosilicate anions based on chemical shifts. {sup 27}Al NMR spectra of aluminosilicate solutions reveal peaks corresponding to Al bound to zero, one, two, and three siloxane bonds. The distribution of aluminosilicate anions is affected by the concentration of dissolved Si and Al, as well as the solution pH. The distribution of aluminosilicate species is described in terms of simple chemical equilibria. {sup 29}Si and {sup 11}B NMR spectra of borosilicate solutions indicate that borate anions are less reactive than aluminate anions. {sup 11}B NMR spectra reveal only a small fraction of the dissolved B appears to form borosilicates.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5852015
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 95:1; 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 27
ALUMINIUM COMPOUNDS
ALUMINIUM ISOTOPES
ALUMINIUM SILICATES
BORON 11
BORON COMPOUNDS
BORON ISOTOPES
BORON SILICATES
DATA
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MATERIALS
MEASURING METHODS
MINERALS
NUCLEAR MAGNETIC RESONANCE
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
OXYGEN COMPOUNDS
RESONANCE
SILICATES
SILICON 29
SILICON COMPOUNDS
SILICON ISOTOPES
STABLE ISOTOPES
ZEOLITES