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LEV |
[B]-Levyne |
Si(89), B(11) |
| Contributed by: | Giuseppe Bellussi and Angela Carati | ||
| Verified by: | Li Shi and by S. B. Hong | ||
| Type Material: | (Na,H)5[B5Si49O108] :8 Q: 5 H2O a (Q= quinuclidine) | ||
| Method: | R Millini, A. Carati, G. Bellussi [1] | ||
| Batch Composition: | 3.0 Q: B2O3 : 3.0 SiO2 : 60 H2O | ||
| Source Materials | |||
| distilled
water quinuclidine (1-azabicyclo[2.2.2]octane) (Aldrich, 97%) boric acid (H3B03) (Carlo Erba RPE-ACS) silica sol (Dupont HS-40, 40% SiO2, 0.3% Na2O) |
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| Batch Preparation | (for 19 g dry product) | ||
| (1) (10 g water + 14.7 g
quinuclidine], mix until dissolved (2) [61 g water + 10.8 g boric acid + 14.7 g quinucidine], mix until dissolved (3) [39.5 g silica sol + (1)], mix until a uniform gel is obtained (4) [(3) + (2)], add solution (2) to gel slowly with vigorous mixing. Final slurry pH ~ 11 |
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| Crystallization | |||
| Vessel: stainless-steel
autoclave Time: 5 days Temperature: 170oC Agitation: autoclave is rotated 20 rpm |
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| Product Recovery | |||
| (1) Filter to recover
solids (2) Wash with distilled water (3) Dry at l20oC (4) Yield: 90% on SiO2 |
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| Product Characterization | |||
| XRD: LEV
(only crystalline phase), a = 12.944 Å, c = 2 1.914 Å Elemental Analysis: 17 SiO2: B2O3: 2.7 Q(dry basis)b Crystal Size and Habit: Compact spherical aggregates (4 to 8 um) of small crystals |
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| Reference | |||
| [1] R. Mimi, A. Carati, G. Beilussi, Zeolites 12 (1992) 265 | |||
| Notes | |||
| a
Protonated quinuclidine (HQ+) or Na+ (from silica
sol) act as counterions for structural boron. b By thermal analysis, organic material adsorbed in extra framework pores is eliminated at 268oC. After treatment at 550oC for a few hours, a limited structure collapse is observed with formation of amorphous material and trigonal BO3 units. [1] |
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