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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Effect of sonication on the particle size of montmorillonite clays

Texto completo
Autor(es):
Poli, Alessandra L. [1] ; Batista, Tatiana [1] ; Schmitt, Carla C. [1] ; Gessner, Fergus [1] ; Neumann, Miguel G. [1]
Número total de Autores: 5
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Inst Quim, BR-13560970 Sao Carlos, SP - Brazil
Número total de Afiliações: 1
Tipo de documento: Artigo Científico
Fonte: Journal of Colloid and Interface Science; v. 325, n. 2, p. 386-390, SEP 15 2008.
Citações Web of Science: 43
Resumo

This paper reports on the effect of sonication on SAz-1 and SWy-1 montmorillonite suspensions. Changes in the size of the particles of these materials and modifications of their properties have been investigated. The variation of the particle size has been analyzed by DLS (dynamic light scattering). In all cases the clay particles show a bimodal distribution. Sonication resulted in a decrease of the larger modal diameter, as well as a reduction of its volume percentage. Simultaneously, the proportion of the smallest particles increases. After 60 min of sonication, SAz-1 presented a very broad particle size distribution with a modal diameter of 283 nm. On the other hand, the SWy-1 sonicated for 60 min presents a bimodal distribution of particles at 140 and 454 nm. Changes in the properties of the clay suspensions due to sonication were evaluated spectroscopically from dye-clay interactions, using Methylene Blue. The acidic sites present in the interlamellar region, which are responsible for dye protonation, disappeared after sonication of the clay. The changes in the size of the scattering particles and the lack of acidic sites after sonication suggest that sonication induces delamination of the clay particles. (c) 2008 Elsevier Inc. All rights reserved. (AU)

Processo FAPESP: 03/07770-4 - Interações de luz visível com polímeros: fotopolimerização e fotodegradação
Beneficiário:Miguel Guillermo Neumann
Linha de fomento: Auxílio à Pesquisa - Temático