Contributed by David Vaughan

Verified by P. Piccione and by B. Subotic

Type Material (Na₈₂K₆₆TEA₁₆)[Al₁₆₄Si₅₀₈O₁₃₄₄] : wH₂O (TEA = tetraethylammomum)

Method D. E. W. Vaughan, K. G. Strohmaier [1,2]

Batch Composition 0.4 K₂O : 0.6 Na₂O : 1.4 (TEA)₂O : Al₂O₃ : 9 SiO₂ : 0.3 Na₂SO₄ : 140 H₂O

Source Materials

deionized water
potassium hydroxide (J. T. Baker, >99% KOH. 0.5 H₂O)
sodium hydroxide (J. T. Baker, ~99% NaOH)
alumina (Alcoa C-31, >99% Al₂O₃^. 3 H₂O)
silica sol (Dupont HS-40, 40% SiO₂, 0.4% Na₂O)
tetraethylammonium hydroxide (SACHEM, 35% N(C₂H₅)₄OH)
aluminum sulfate (reagent grade,> 99% Al₂(SO₄)₃. 17H₂O)

Batch Preparation (for 20 g dry product)

(1) [8.0 g water + 1.79 g potassium hydroxide + 2.8 g sodium hydroxide + 5.1 g alumina], reflux until a clear solution is obtained; cool to room temperature. Replace water lost by evaporation
(2) [10 g aluminum sulfate + 10 g water], mix and warm if necessary to make a solution
(3) [49.7 g silica sol + 43.3 g tetraethylammonium hydroxide + (1) + 5.29 g (2) + 19 g water], add sequentially with mixing in a beaker

Crystallization

Vessel: 125 mL Teflon jar (Nalgene)
Incubation: 3 days at room temperature
Time: 12 to 16 days^a
Temperature: 100¡C
Agitation: none

Product Characterization

XRD: excellent PAU
Elemental Analysis: 0.4 K₂O : 0.5 Na₂O : 0.1 (TEA)₂O : Al₂O₃ : 6.2 SiO₂: H₂O
Crystal size and Habit: spherical aggregates (1 to 10um) of submicron crystals (<0.1 to 0.2 um)^b
Click here to view XRD pattern

References

[1] D. E. W. Vaughan, K. G. Strohmaier, U. S. Patent 5 013 536 (1991)
[2] D. E. W. Vaughan, K. G. Strohmaier, Micropor. Mesopor. Mater. 28 (1999) 233

Notes

a. Both 12 and 16 day samples were excellent PAU.

b. ¹³C-NMR shows two sites; ²⁹Si-NMR shows three broad peaks.