Layered silicate by proton exchange and swelling of AMH-3

Proton-exchanged AMH-3 was prepared by ion exchange of interlayer cations of the layered silicate AMH-3 using an aqueous solution of amino acid. Moreover, swollen AMH-3 was prepared by a procedure involving sequential intercalation of primary amine molecules following proton exchange. Structural characteristics of both AMH-3 derivative materials were investigated using characterization techniques such as XRD, SEM, TEM, NMR, FT-IR, TGA, and N-2 adsorption. Both processes lead to structural changes and condensation of silanol groups located on the silicate layer surface. Proton-exchanged AMH-3 is an amorphous powder with the same particle size and shape as the original AMH-3 crystals. Due to the structural changes, swollen AMH-3 should be considered as a new layered silicate material rather than an intercalated phase. The swollen AMH-3 powder shows limited evidence for the presence of a nanoporous framework, suggesting that its use as a molecular sieve additive for improved selectivity nanocomposite membranes is worth exploring. (C) 2008 Elsevier Inc. All rights reserved.