The preparation of bentonite-ionene complexes based on the adsorption of 2y-ionenes, where y = 4, 6, 10 or 12 and an ionene of the epichloridrin-dimethylamine EPI-DMA kind, was carried out in order to observe the behavior of the ionene spacer size in the expansion of the basal space (d-spacing, d001) of a Brazilian commercial bentonite. The complexes were characterized by adsorption spectromety in the infrared region, thermogravimetry, fluorescence and X-Ray diffraction. Ionenes were synthesized and characterized by infrared and nuclear magnetic resonance, the latter technique being useful for determining the average number molecular weight values. Based on the clay-ionenes complexes it could be observed that the ammonium polyquaternaries are adsorbed on the inner and outer clay surfaces, above the ion exchange capacity, CEC = 91 meq/100 g clay (calculated based on X-Ray fluorescence data). The clay basal expansion with the several polycations revealed that the spacer size is the most important factor, independent of ionene molecular weight values. Among the bentonite-ionene complexes, mainly between Bt-2,10 and Bt-2,12-ionene complexes which differ in molar mass by more than 30,000 g/mol, it was observed that the spacer size has no dependence on the ionene molecular weights.
Ionene polymers; organobentonite; hydrocarbon spacers; pollutants
