N2 and CO2 gases adsorption by tetramethylammonium(TMA)-montmorillonites and hexadecylpyridinium(HDP)-montmorillonites was carried out using volumetric equipment at 25 °C and 0.1 MPa. The addition of organic compounds to montmorillonites was 1 and 4 times the cation exchange capacity (CEC) of the montmorillonites and the contact times between the TMA (or HDP) and the montmorillonites were 4 and 24 h. The adsorptions of CO2 by TMA-montmorillonites (0.383-0.477 mmol/g) were higher than those by HDP-montmorillonites (0.027-0.060 mmol/g). N2 gas retentions by organo-montmorillonites were small: in the range of 0.038-0.065 mmol/g TMA-montmorillonites and around 0.010 mmol/g HDP-montmorillonites. The interlamellar spacing of the organo-montmorillonites, the structure of the intercalated organic molecule, and the type of montmorillonites influenced the gas adsorption values.

Organo-clays were prepared by exchange cations of the montmorillonite with tetramethylammonium (TMA)- and hexadecylpyridinium (HDP)-chloride. Two different montmorillonite types were studied. Two amounts of each organic substances (1 and 4 cation exchange capacity times of montmorillonite) were contacted with each montmorillonite clay for 1 and 24 h. The solids were characterized by X-ray diffraction and swelling index. The swelling was measured in water and toluene media. The structural characteristics of montmorillonites changed after organo treatment and showed different behaviour in water and toluene media. The type of montmorillonite, the organic cation intercalates (TMA, HDP) and condition of treatment influenced in the different swelling in water and toluene media.