Hidroxi-polymers of Al and Ti were synthesized after hydrolysis of its respective salts
and are being used in the intercalation and pillarization of smectites of different chemical
composition. The intercalation methodology consists mainly in the substitution of
interlamelar cations by bigger cations {aluminium polyhroxipolymer so-called Keggin ion,
Al13 complex, [Al13O4(OH)24(H2O)12]7+ and Titanium polyoxycation, TiOx(OH)2x} followed
by further drying at 80ºC. The resultant material of the intercalation must suffer calcinations
at T=300-500ºC (pillarization), with the main purpose of removing interlayer water. The
natural and pillared clays were characterized by XRD, FTIR, 27Al and 29Si NMR, TGA-TG
and textural analysis using N2 adsorption/desorption isotherms. The samples were used as
adsorbents in the adsorption process with butylamine (Al-PILC/acid activation) and Cu2+, Ni2+ and Co2+ solutions (Al-PILC and Ti-PILC).
The results of XRD patterns show that the d(001) spacing increases of d001= 15,30-15,60
to d001= 18,36-18,92 Å (Al-PILC) and of d001= 15,30 to d001= 17,10-19,56. Å (Ti-PILC).
FTIR spectra have proved smectites pillarization with Al and Ti by vibrations at 667 cm-1 (Al-
O bond of tetrahedrally coordinated Al cations in the center of the Al13 pillars) and 1338 cm-1
(Ti-O bond of the TiO2 pillars). The 27Al RMN spectra show that Al-PILC samples presents
signals of 68 ppm and 0 ppm related to the Al in the tetrahedral and octahedral positions,
respectively. It was indicate that the TGA-TG curves are similar itself. Endothermic peaks
were observed. The first one occurs at 100-200 ºC and is assigned to loss of surface
physisorbed water and loosely coordinated water. The second occurs at 300-600 ºC
corresponding to the dehydroxilation of the Hidroxi-polymers. Textural parameters have also
increased which resulted in the classification of this pillared smectites as a microporous to
mesoporous material.
The adsorption of butylamine and Cu2+, Ni2+ and Co2+ ions from aqueous solution in room
temperature onto PILCs show that the Langmuir, Freundlich and Temkin adsorption
isotherms models have been applied to fit the experimental data by linear regression. The onesurface
Langmuir equation provided the best fit to the data (r=0,999). The Freundlich
equation presented limitations in rises concentrations, but acceptable values of parameters
were obtained (Kf and n) with the use of the three models. The parameters were used to calculate the amount adsorbed (Nf), a function of Cs.
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