Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/25255
Type: Artigo de periódico
Title: Morphological evaluation of silicone/clay slurries by small-angle/wide-angle x-ray scattering
Author: Kaneko, Manuela L. Q. A.
Torriani, Íris L.
Yoshida, Inez V. P.
Abstract: Silicone/clay slurries were prepared by mechanical blending of different silicone fluids and montmorillonite clays. Two dispersion series containing (1) a natural montmorillonite (MMT) and (2) an organic montmorillonite (O-MMT) were prepared using poly (dimethylsiloxane) with -Si(CH3)2OH end groups (PDMS-OH), poly(dimethylsiloxane-co-methylpropylethylene oxide siloxane) (PDMS-PEO) or a poly(dimethylsiloxane-co-aminoethylaminopropylmethylsiloxane)/water emulsion (PDMS-NH2) as dispersion fluids. The resulting morphology of the silicone/clay slurries was characterized by small-angle/wide-angle X-ray scattering using a two-dimensional imaging plate detector (2D-SAXS/WAXS). The PDMS-OH/clay slurries showed only a slight increase in the layer separation while a more pronounced effect was found for the PDMS-NH2 and PDMS-PEO slurries, which resulted in expanded tactoids. Analyses in the SAXS region also indicated the existence of thin platelets for the MMT slurries prepared with PDMS-NH2 and PDMS-PEO fluids. This hierarchical structure, formed by thin platelets and expanded tactoids, was also found in the O-MMT/silicone slurries.
Pastas de argilas em siliconas foram obtidas por mistura mecânica de diferentes fluidos de silicona e argilas montmorillonitas. Duas séries de pastas contendo (1) montmorillonita natural (MMT) e (2) montmorillonita orgânica (O-MMT) foram preparadas usando poli(dimetilsiloxano) com finais de cadeias Si(CH3)2OH (PDMS-OH), poli(dimetilsiloxano-co-metilpropilóxido de etileno siloxano) (PDMS-PEO) ou emulsão de poli(dimetilsiloxano-co-aminoetilaminopropilmetilsiloxano) em água (PDMS-NH2). A morfologia das pastas foi caracterizada por espalhamento de raios-X em baixo/alto ângulo usando detector bidimensional (SAXS/WAXS-2D). As pastas preparadas com PDMS-OH apresentaram apenas um aumento discreto na separação das lamelas, enquanto aquelas preparadas com PDMS-PEO e PDMS-NH2 apresentaram um aumento pronunciado, resultando em tactóides expandidos. Além disso, a análise da região de SAXS indicou a presença de lâminas finas (lamelas esfoliadas e/ou empilhamento de poucas lamelas) e tactóides expandidos nas pastas MMT/PDMS-PEO e MMT/PDMS-NH2. Esta estrutura hierárquica também foi encontrada nas pastas preparadas com a O-MMT.
Subject: montmorillonite
silicone
SAXS/WAXS
Editor: Sociedade Brasileira de Química
Rights: aberto
Identifier DOI: 10.1590/S0103-50532007000400015
Address: http://dx.doi.org/10.1590/S0103-50532007000400015
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532007000400015
Date Issue: 1-Jan-2007
Appears in Collections:Artigos e Materiais de Revistas Científicas - Unicamp

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