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KFI |
High-Silica KFI |
Si(79), Al(21) |
Contributed by Alain Matijasic and Joël Patarin
Verified by S. Schwarz, by K. Strohmaier, and by S. Miller
Type Material K18Sr[Al20Si76O192] .72 H2O. (18-C-6) (18-C-6 = Cycl. (C2H4O)6)
Method T. Chatelain, J. Patarin, R Farré, O. Pétigny, P. Schulz [1]
Batch Composition 2.3 K2O : 0.1 SrO : Al2O3 : 10 SiO2 : 220 H2O : 1.0(18-C-6)
Source Materials
distilled water
potassium hydroxide (Prolabo, 86% KOH)
aluminum hydroxide (Fluka, 99+% Al(OH)3)
strontium nitrate (Prolabo >97% Sr(NO3)2)
silica sol (Dupont Ludox AS-40, 40% SiO2)
18-C-6 (Lancaster,> 98% cycl. (C2H4O)6)
Batch Preparation (for 7 g of as-synthesized product)
(1) [11.00 g water + 3.00 g potassium hydroxide + 1.57 g aluminum hydroxide], heat to boiling until clear, cool to room temperature and correct weight loss due to boiling a
(2) [18.63 g water + 0.22 g strontium nitrate + 2.70 g 18-C-6 + 15.00 g silica soil, stir until homogenized
(3) [(1) + (2)], mix for 30 mm. (forms a thick gel). Transfer to a 120 mL PTFE-lined stainless steel autoclave. Final pH:14
Crystallization
Vessel: PTFE-lined stainless steel autoclave
Time: 120 hours
Temperature: 1500C in a preheated oven
Agitation: none; final pH: approximately 13
Product Recovery
(1) Dilute the reaction mixture with distilled water
(2) Filter and wash until pH ~ 10
(3) Dry at 600C overnight
(4) Yield: Total ~ 7 g of as-synthesized KFI-type sample (product contains 18-C-6 as organic template, ~ one molecule per unit cell b
Product Characterization
XRD Highly crystalline KFI; can be indexed with cubic symmetry, a0=18.671(l)Å b
Elemental Analyses: Si/Al = 3.7 b
Crystal Size and Habit: by SEM, the crystals display a cubic morphology; most of them are aggregated and their sizes range from 2 to 4 um
Click here to view XRD pattern
Reference
[1] T. Chatelain, J. Patarin, R. Farré, O. Pétigny, P. Schulz, Zeolites 17 (1996) 328
Notes
a. The starting mixture is prepared in a polyethylene vessel.
b. According to ref. [1].