(165m) Mechanochemical Synthesis of Large Area Mg-Al LDH Macrosheets

Layered double hydroxides (LDHs) are a class of ionic lamellar compounds made up of positively charged brucite-like layers with an interlayer region containing charge compensating anions and solvation molecules. Delamination of LDHs is an interesting route for producing positively charged thin platelets with a thickness of a few atomic layers, which can be used as nanocomposite supporters. Traditionally, the LDHs are prepared by co-precipitation of different metal salts at alkaline conditions, which produces waste solvents. In this study, a mechanochemical (MC) route was used to synthesize Mg-Al LDH macrosheets, and several different intercalated anionic surfactants were introduced to delaminate them to thinner sheets, In addition, the milling parameters were optimized. The as-obtained products were characterized by various techniques, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermogravimetry (TG), Differential scanning calorimetry (DSC) and Scanning electron microscopy (SEM). The products of Mg-Al LDH showed high crystallinity, large laminar area, with no impurity phases, suggesting huge potential of using this green route for synthesis of LDHs for versatile applications. Furthermore, the possible mechanism for Mg-Al LDH formation in the MC process was proposed, the results presented provide a systematic understanding of the preparation of LDH macrosheets.