Modification of cationic nanoclays with ionic liquids

As part of a broader effort to develop nanoclays functionalized with different heterocyclic aromatic structures for novel applications, preliminary data are reported on the modification of sodium montmorillonite, a cationic clay, with three low molecular weight pyridinium- and imidazolium-based ionic liquids. Commercially available unmodified clay was treated under different conditions with aqueous solutions of three ionic liquids: N-ethyl pyridinium tetrafluoroborate, 1-ethyl 3-methyl imidazolium bromide and 1-hexyl 3-methyl imidazolium chloride. The modified materials were characterized qualitatively and quantitatively by FTIR, TGA, EDX, WXRD and elemental analysis. The data show an overall increase in interlamellar spacing as a result of sodium cation exchange with the cations of the ionic liquids and improved thermal stability vs. commercial nanoclays modified with long chain quaternary ammonium salts. The effects were dependent on the type of the ionic liquid. Data are also reported on the evaluation of the modified clays in the preparation of polypropylene nanocomposites. (c) 2006 Elsevier Inc. All rights reserved.