Abstract
Composites of smectite / layered double hydroxide (LDH) were synthesized by various methods and their porous properties and microstructures examined. Commercial saponite and co-precipitated LDH [Mg6Al2(CO3)(OH)16-4H2O] powders were used. Composites prepared by dry mechanical mixing, wet mechanical mixing and soft-chemical processing were characterized by XRD, FT-IR, XPS, SEM, TEM, and N2 adsorption. The specific surface areas of the samples were intermediate between those of LDH and saponite. The value for the dry milled sample (167 m2/g) was smaller than for the other samples (about 250 m2/g). The pore size distributions of the saponite / LDH composites differ from those of the saponite and LDH, the peaks ranging from 1nm to 30nm according to the synthetic method. The resulting porous properties depend on laminating structure. Dry milling was the most effective method for modifying porous properties of the composites.
