Intercalation of dodecyl sulfate into layered double hydroxides

The intercalation of sodium dodecyl sulfate and exchange of dodecyl sulfate anion into layered double hydroxides has been examined by means of X-ray diffraction, infrared and thermogravimetric procedures. Three types of derivatives were obtained having mean interlayer spacings of 26 Å, 36 Å and 47 Å, respectively. These interlayer distances did not correlate with the amount of organic incorporated between the layers but, as shown by computer simulations, depended upon the orientation of the chains within the interlamellar space. In several reactions both intercalation of neutral sodium dodecyl sulfate as well as exchange of the dodecyl anion took place. Attempts to remove the alkyl sulfate chains with dilute acid resulted in dissolution of the more basic metals producing non-stoichiometric layered products.