RODRIGO UCHIDA ICHIKAWA

Projetos de Pesquisa
Unidades Organizacionais
Cargo

Filtros

20171
Limpar filtros

Configurações

Fator de Impacto: 4.500 - 5.999 ×

Resultados de Busca

Agora exibindo 1 - 1 de 1
  • Imagem de Miniatura
    Artigo IPEN-doc 23161
    Aluminum hydroxide gel characterization within a calcium aluminate cement paste by combined Pair Distribution Function and Rietveld analyses
    2017 - CUESTA, ANA; ICHIKAWA, RODRIGO U.; LONDONO-ZULUAGA, DIANA; DE LA TORRE, ANGELES G.; SANTACRUZ, ISABEL; TURRILLAS, XAVIER; ARANDA, MIGUEL A.G.
    There are many commercially importantmultiphasematerialswhich contain amorphous phases, such as cement pastes, porcelains, glass-ceramics or pharmaceutical compounds. However, the analysis of amorphous phase(s) within cement matrices that contain high amounts of crystalline phase(s) is a challenge. Here, we report measurements of total scattering data quantitatively analyzed by Pair Distribution Function (PDF) minimization and Rietveld methodology to determine phase compositions including both amorphous and nanocrystalline phase contents in cement-related samples. Furthermore, laboratory techniques were used to complement the sample characterization. In addition to five reference materials, the main phase of calcium aluminate cements, CaAl2O4 hydrated at 50 °C to yield crystalline hydrogarnet, Ca3Al2(OH)12, (43wt%) and nanocrystalline aluminum hydroxide gel, Al(OH)3·0.1H2O (50wt%)was also investigated. The PDF analyses revealed that the hydroxide gel has a gibbsite local structurewith an average particle size close to 5 nm. PDF and Rietveld quantitative phase analysis results fully agree.