One-pot green hydrothermal synthesis of stearate-intercalated MgAl layered double hydroxides

A convenient one-pot green hydrothermal synthesis method has been developed to obtain stearate-intercalated layered double hydroxide (LDH-St), an important nanofiller for polymer/LDH nanocomposites. Various factors of the hydrothermal synthesis conditions, including reaction time, temperature and solid content, were taken into account. The resulting products were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), inductively coupled plasma (ICP) atomic emission spectrophotometry, CHN elemental analysis, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The increase of reaction time or solid content is helpful to the formation of LDH-St, whereas high reaction temperature had little effect. Deduced from PXRD and the composition analysis results, prolonging of reaction time led to a packing arrangement transformation from a bilayer-like structure with stearate acids co-intercalated to monolayer for the intercalated stearate anions in the interlayer space. In addition the prepared LDH-St crystallites showed flower-like aggregates with a diameter of about 8-10 mu m consisting of sheets with irregular shape. (c) 2013 Elsevier B.V. All rights reserved.