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Synthesis of Nanosized Mullite from Aluminosilicate Precursors
| Content Provider | Semantic Scholar |
|---|---|
| Author | Buljan, Iva Kosanović, Cleo |
| Copyright Year | 2011 |
| Abstract | As it is found in our previous study [1], the controlled heating of ammonium-exchanged zeolite A resulted in the formation of an amorphous aluminosilicate, followed by desorption of water and ammonia. Except of bulginess formed on the particle surfaces as a result of the internal pressure of gas (NH3) developed by thermal decomposition of NH4 + ions inside zeolite A micro-crystals, the resulting particles of the amorphous aluminosilicate kept the size and shape of the precursor micro-crystals (NH4-exchanged zeolite A). A prolonged heating of the amorphous aluminosilicate resulted in its transformation into a mixture of mullite (63.4 wt. %), amorphous SiO2 (33.9 wt. %) and Na2SiO3 (2.7 wt. %). Resulting particles have the same size and shape as the particles of the starting amorphous aluminosilicate. The preserving of the particulate properties during the transformation processes led to the conclusion that each zeolite micro-crystal acted as a “closed” micro-reactor with a stable shell, and all relevant processes (crystal to amorphous transformation, nucleation and crystal growth of mullite from the amorphous aluminosilicate) occurred inside each single particle (crystal). This furthermore implied that mullite, SiO2 and Na2SiO3 did not appear as separate particulate systems, but that all phases existed as their physical mixture inside each single particle (micro-reactor). |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://www.zeolit.hr/dok/2009_Ljubljana/11_2SCSZ.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
