Thermal Characterization of Poly(styrene sulfonate)/Layered Double Hydroxide Nanocomposites

Christopher O. Oriakhi, Isaac V. Farr and Michael M. Lerner
Department of Chemistry and Center for Advanced Materials Research, Oregon State University, Corvallis, Oregon 97331

Abstract: Phase and morphological changes during thermolysis of Mg4Al2(OH)12CO3·nH2O and Zn6Al2(OH)16CO3·nH2O layered double hydroxides (LDH) and their nanocomposites with poly(styrene sulfonate) (PSS) are studied by X-ray powder diffraction (XRD), scanning and transmission electron micrography (SEM and TEM) and thermal analyses. Mg4Al2(OH)12CO3·nH2O and Mg2Al(OH)6[CH2CH(C6H4SO3)]·3H2O show comparable thermal stabilities: the layered structure is lost above 300 °C with the nucleation of the MgO phase at approximately 400 °C and the MgAl2O4 phase at approximately 800 °C Zn3Al(OH)8[CH2CH(C6H4SO3)]·nH2O undergoes complete oxidative pyrolysis of the polyanion by 500 °C. Crystalline oxide products are obtained at a temperature approximately 300 °C lower than that of thermolysis of Zn6Al2(OH)16CO3·nH2O. The SEM and TEM images show that the thermolysis of LDH carbonates produces dense aggregates containing microcrystalline particles, whereas Mg2Al(OH)6[CH2CH(C6H4SO3)]·3H2O forms a macroporous solid.

Key Words: Layered Double Hydroxides • Nanocomposites • Poly(styrene sulfonate)

Clays and Clay Minerals; April 1997 v. 45; no. 2; p. 194-202; DOI: 10.1346/CCMN.1997.0450207
© 1997, The Clay Minerals Society
Clay Minerals Society (www.clays.org)