Size-controlled layered zinc hydroxide intercalated with dodecyl sulfate: effect of alcohol type on dodecyl sulfate template

Abstract

Layered zinc hydroxide intercalated with dodecyl sulfate (LZH-DS) was prepared by facile alkaline precipitation method in a short reaction time at room temperature. We also controlled the size of the layered structures with different kinds of alcohols (ethanol, 1-propanol, 1-butanol and 1-pentanol), and not by controlling variables such as process temperature and aging time. The synthetic mechanism of large LZH-DS was explained using concepts of the extra- and intra-lamellar template models. The extra-lamellar template consisted of a few SDS bilayers in which zinc atoms electrostatically interacted with sulfate groups and the alcohols were laterally located between dodecyl sulfate molecules. Due to hydrophobic and ion-dipole interactions, the extra-lamellar template with the long alkyl chain alcohols was more packed and had greater stability resulting in formation of large LZH-DS. Regardless of the type of alcohol, the LZH-DS was octagonal shaped. The SAED pattern displayed hexagonally arranged spots, which was considerably different from the overall octagonal shape of LZH-DS. On the basis of TGA and EDS results, the chemical formula of LZH-DS synthesized with 1-pentanol was Zn(OH)_1.42(C₁₂H₂₅SO₄)_0.47(Cl)_0.11·0.90H₂O, and the crystal structure was a hydrozincite-type structure.