Article ID Journal Published Year Pages File Type
73802 Microporous and Mesoporous Materials 2013 11 Pages PDF
Abstract

Stable mesoporous delaminated and silicate-bearing hectorites were synthesized at short times (1–2 h) varying the pH of the hydrothermal treatment (7 and 10) and using microwaves and ultrasounds during the synthesis. The use of microwaves, ultrasounds and aging pH of 10 improved hectorite crystallinity. Additionally, longer times of ultrasounds involved a better incorporation of magnesium and lithium cations in the octahedral sheet for the delaminated hectorites prepared a pH 7. Delaminated hectorites showed higher BET areas (536–603 m2/g) than silicate-bearing hectorites, due to delamination and probably to the presence of magnesium vacancies in the octahedral sheet. The formation of vacancies was favored with the use of microwaves and at short times of ultrasounds. This agrees with the C.E.C. values and the low amounts of lithium obtained for delaminated samples.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Mesoporous delaminated and silica-bearing hectorites were synthesized at short times. ► Use of microwaves, ultrasounds and aging pH of 10 improved hectorite crystallinity. ► Longer times of ultrasounds involved better incorporation of Mg and Li in the Oh sheet. ► Mesoporous delaminated hectorites showed high surface areas (536–603 m2/g).

Related Topics
Physical Sciences and Engineering Chemical Engineering Catalysis
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