Contributed by Valentin Valtchev

Type Material (SiO₂)136 q R. q » 10, (R = TMA⁺ and TrMA) ^a

Batch Composition 15 Na₂O:16 TrMA:16 (TMA)Cl : 55 SiO₂ : 3387 H₂O: 10 H₂SO₄ ^b,c

bidistilled water
sodium silicate (Riedel de Haen, 63% SiO₂, 18% Na₂O, 18% H₂O)
sulfuric acid (98% H₂SO₄)
trimethylammonium (TrMA) chloride (Merck, 98% TrMA^. HCl)
tetramethylammonium (TMA) chloride (Merck,> 98% (TMA)Cl

(1) [300 g water + 52.5 g sodium silicate], heat and stir until dissolved ^d
(2) [150 g water + 10.7 g sulfuric acid]
(3) [(1) + (2)], mix thoroughly
(4) [15.29 g trimethylanimonium chloride + 17.54 g tetramethylainmonium chloride + 150 g water], mix thoroughly
(5) [(3) + (4)], mix thoroughly; pH 9.2 to 9.5

Vessel: stainless steel or Teflon jar
Time: 12 to 14 days
Temperature: 200¡C
Agitation: none

(1) After crystallization, pH 10.5
(2) Filter to recover solids, and wash with hot water
(3) Dry at ambient temperature (drying at 90-110¡C acceptable)
(4) Yield: 88% based on silica

XRD: MTN only crystalline phase,^e a₀ = 19.39 Å, single crystal structure refinement [2];
competing phases: NU-1 (when gel contains aluminum), quartz (when pH of starting gel >11.5)
Elemental Analysis: 0.0018 Na₂O. SiO₂ ^f
Crystal Size and Habit octahedral morphology, 100 to 200 nm dia. [1]
Click here to view XRD pattern

[1] I. Vergiov, V. Valtchev, Zeolites 11 (1991) 387
[2] J. Macicek, V. Valtchev, G. Kirov, in Collected Abstracts, 14th Congress and General Assembly Int. Union of Crystallography, H. C. Freeman (ed.), Lamb Printers, Perth, Australia, 1987, C-134

a. Crystalline product is 7.4 wt% TMA⁺ and TrMA by thermal analysis.

b. With TMA⁺ only, complex crystal twins are formed.

c. H₂O includes water from sodium silicate, sulfuric acid and added water.

d. Sodium silicate solution must be heated and stirred until converted to a clear solution.

e. XRD patterns of as-synthesized product and product after 600¡C calcination do not differ significantly.

f. Analysis of ZSM-39 calcined for 1 hour at 950^¡C in air gave 94.7% SiO₂, 0.17% Na₂O, and a remainder, probably consisting of carbonaceous material and water.