Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1694176 | Applied Clay Science | 2016 | 11 Pages |
Abstract
The effect of the microwave assisted acid treatment (MAT) on the structure and texture of dioctahedral (montmorillonite and nontronite) and trioctahedral (saponite and stevensite) smectites were studied by SEM, nitrogen adsorption, XRF, XRD and FTIR. The effectiveness of this treatment is notably influenced by the chemical composition of the octahedral sheet. Thus, trioctahedral smectites seem to be very reactive to the microwave assisted acid treatment. In saponite and stevensite this treatment caused in the first 20Â min the progressive Mg2Â + depletion of the octahedral sheet, the gradual destruction of the smectite structure and the formation of an amorphous silica phase which contributes to a noticeable increase of the BET specific surface area. After 20Â min of microwave assisted acid treatment the increase in SSA is of 315Â m2/g in saponite and 244Â m2/g in stevensite. The assistance of microwaves during the acid treatment allows us to get, in 20Â min, specific surface areas equivalent to those obtained after 48Â h with conventional heating methods. On the contrary, dioctahedral smectites seems to be less reactive to the microwave assisted acid treatment.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geochemistry and Petrology
Authors
Francisco Franco, Manuel Pozo, Juan Antonio Cecilia, Mónica BenÃtez-Guerrero, Mónica Lorente,