Mg-Al layered double hydroxides (LDHs) were intercalated with various molecular-weight poly(oxypropylene)-bis-amidoacid salts LDHs at 120 degreesC and under N-2 atmosphere in an autoclave to afford a series of organoclays with a maximal basal spacing of 92 Angstrom, revealed by X-ray diffraction and transmission electron microscopy analyses. The unusually wide interlayer spacing was ascribed to the self-alignment of the hydrophobic POP backbone in the layer confinement. In contrast, the intercalation of poly(oxyethylene)-bis-amidoacids (POE-acid) afforded a low basal spacing (7.8 Angstrom) due to their oxyethylene-backbone interaction with the layered surface. The resultant POP- and POE-acid intercalated LDHs also exhibited different dispersing properties in toluene or water. Particularly, the organically-modified and spaceenlarged hybrids with a proper amount of the embedded POPs possessed an amphiphilic property of lowering the toluene/water interfacial tension. (C) 2004 Elsevier Ltd. All rights reserved.