CETMIC   05378
CENTRO DE TECNOLOGIA DE RECURSOS MINERALES Y CERAMICA
Unidad Ejecutora - UE
artículos
Título:
Physicochemical Characterization of Al-pillared montmorillonites obtained by microwave irradiation
Autor/es:
S. YAPAR; R. M. TORRES SÁNCHEZ; M. EMREOL; P. WEIDLER; K. EMMERICH
Revista:
CLAY MINERALS (PRINT)
Editorial:
Mineralogical Society of Great Britain and Ireland
Referencias:
Lugar: London; Año: 2009
ISSN:
0009-8558
Resumen:
In this study, a new procedure for the synthesis of pillared clays is proposed. Ageing
process and intercalation reaction were carried out by using microwave irradiation in order to
decrease the consumption of three important industrial parameters; time, water and energy.
The effects of microwave irradiation, the amount of aluminium and Al3+/clay ratio on the
physicochemical properties of Al-pillared montmorillonites were investigated. The structural
changes depending on the intercalation and microwave irradiation were determined by
conducting the XRD, FTIR and SEM analyses and by measuring specific surface area, pore
size distribution. Additionally, STA analyses and zeta potential measurements were carried
out to determine the physicochemical properties. According to the XRD measurements, d0013+/clay ratio on the
physicochemical properties of Al-pillared montmorillonites were investigated. The structural
changes depending on the intercalation and microwave irradiation were determined by
conducting the XRD, FTIR and SEM analyses and by measuring specific surface area, pore
size distribution. Additionally, STA analyses and zeta potential measurements were carried
out to determine the physicochemical properties. According to the XRD measurements, d001001
value of microwave irradiated samples is not affected by the amount of aluminium and
Al3+/clay ratio and microwave irradiation causes a 0.20 nm contraction in d001 value
comparison to that of conventionally pillared sample. Additionally all d001 peaks have
symmetry indicating a satisfactorily ageing of the pillaring solution and intercalation of
Keggin ions. The results of FTIR analyses reveal that the intensity of peaks assigned to
Keggin-OH and Keggin-H2O stretches is diminished in the case of microwave irradiated
3
samples. STA analyses indicated that amount of water released during dehydroxylation is
decreased in the case of microwave irradiated samples. By considering the contraction in d0013+/clay ratio and microwave irradiation causes a 0.20 nm contraction in d001 value
comparison to that of conventionally pillared sample. Additionally all d001 peaks have
symmetry indicating a satisfactorily ageing of the pillaring solution and intercalation of
Keggin ions. The results of FTIR analyses reveal that the intensity of peaks assigned to
Keggin-OH and Keggin-H2O stretches is diminished in the case of microwave irradiated
3
samples. STA analyses indicated that amount of water released during dehydroxylation is
decreased in the case of microwave irradiated samples. By considering the contraction in d001001 peaks have
symmetry indicating a satisfactorily ageing of the pillaring solution and intercalation of
Keggin ions. The results of FTIR analyses reveal that the intensity of peaks assigned to
Keggin-OH and Keggin-H2O stretches is diminished in the case of microwave irradiated
3
samples. STA analyses indicated that amount of water released during dehydroxylation is
decreased in the case of microwave irradiated samples. By considering the contraction in d0012O stretches is diminished in the case of microwave irradiated
3
samples. STA analyses indicated that amount of water released during dehydroxylation is
decreased in the case of microwave irradiated samples. By considering the contraction in d001001
values and the decreases in Keggin-stretching bands and also in the amount of
dehydroxylation water, it was concluded that microwave irradiation has calcination effect on
the intercalated Keggin ions.