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https://hdl.handle.net/10316/33048
Título: | Surface properties of calcium carbonate modified with silica by sol-gel method | Autor: | Pedrosa, Jorge Gamelas, J. A. F. Lourenço, Ana F. Ferreira, Paulo J. |
Palavras-chave: | Precipitated calcium carbonate; Silica; Sol-gel method; Surface physical-chemical properties; IGC; XPS | Data: | 24-Fev-2016 | Editora: | Elsevier | Título da revista, periódico, livro ou evento: | Colloids and Surfaces A: Physicochemical and Engineering Aspects | Volume: | 497 | Resumo: | The physico chemical surface properties of precipitated calcium carbonate (PCC) modified with silica by sol-gel method were evaluated using inverse gas chromatography and compared to those of the original PCC. The modification of the surface of PCC crystals by a dense film of silica provided a slight decrease of the dispersive component of the surface energy and a significant decrease of the specific component of the work of adhesion with trichloromethane (a Lewis acidic probe). In addition, interactions measured with weak Lewis bases (1-alkenes) also revealed differences between PCC and PCC-silica samples. Differences in the surface properties (namely of the Lewis acid-base ones) of PCCs modified with distinct silica content (ca. 22 and 30 wt%), were also found, and were interpreted as being due to the different accessibility of silanol groups (Si-OH) on the materials surface: a higher prevalence of these acidic groups in the material with lower silica content increases the specific affinity to Lewis basic probes and decreases the affinity to Lewis acidic probe. X-ray photoelectron spectroscopy results confirmed the presence of silica on PCC, with a higher Si/Ca atomic ratio being found for the material with higher silica content. | URI: | https://hdl.handle.net/10316/33048 | ISSN: | 0927-7757 | DOI: | 10.1016/j.colsurfa.2016.02.020 10.1016/j.colsurfa.2016.02.020 |
Direitos: | openAccess |
Aparece nas coleções: | FCTUC Eng.Química - Artigos em Revistas Internacionais |
Ficheiros deste registo:
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Surface properties of calcium carbonate modified with silica by sol-gel methods.pdf | 246.9 kB | Adobe PDF | Ver/Abrir |
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