Effects of SO42- on the Heterogeneous Precipitation Coating of Hydrous Alumina on TiO2 Particles in an Aqueous Process
| Autor: | and Jun-Ling Duan, Ting-Jie Wang, Yong Jin, Hai-Xia Wu |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
chemistry.chemical_classification
Aqueous solution Materials science General Chemical Engineering Inorganic chemistry General Chemistry engineering.material Industrial and Manufacturing Engineering Divalent law.invention Amorphous solid Film coating Coating chemistry Critical point (thermodynamics) law engineering Titration Crystallization |
| Zdroj: | Industrial & Engineering Chemistry Research. 46:3590-3594 |
| ISSN: | 1520-5045 0888-5885 |
| DOI: | 10.1021/ie061557b |
| Popis: | The effects of foreign inorganic anions on the coating morphologies of TiO2 particles were experimentally studied by investigating the effects of divalent SO42- anions on the precipitation rate, crystallization behavior, and heterogeneous precipitation coating of hydrous alumina. The pH change and critical point of precipitation during base titration into Al3+ solutions were investigated. The precipitation rate of OH−Al species was accelerated by an increase in SO42- concentration, while the crystallization rate was little changed, so that the crystallization was poor and amorphous gels were preferentially formed. Under the same condition, Al(OH)3 gels obtained from Al2(SO4)3 solution or the Al3+ solution with added SO42- anions were close to amorphous, while the Al(OH)3 gels from a pure Al(NO3)3 solution were close to crystalline. The conditions conducive for forming amorphous gels were conducive to forming film coating on the core particle surface. |
| Databáze: | OpenAIRE |
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