Lamellar polymer-Li_xMoO₃ nanocomposites via encapsulative precipitation

With Li_xMoO₃ (x=0.31-0.40) as a host material, a new family of polymer-molybdenum bronze nanocomposites has been synthesized using an exfoliation/encapsulation methodology. Nanocomposites with poly(ethylene oxide), poly(ethylene glycol), poly(propylene glycol), poly(vinylpyrrolidinone), methyl cellulose, polyacrylamide, and nylon-6 were prepared and characterized by thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), powder X-ray diffraction, FTIR spectroscopy, UV-VIS spectroscopy, variable-temperature ⁷Li and ¹³C solid-state NMR spectroscopy and magnetic susceptibility measurements. The electrical conductivity of these materials lies in the range from 10^-2 to 10^-7 S cm^-1, and decreases as the interlayer separation increases. The intercalated polymer imparts both mechanical strength and ease of processing to these materials. The water-soluble polymer-Li_xMoO₃ nanocomposites can be cast into films and other shapes, which may provide opportunities for applications. Factors affecting the intercalation reaction and the structure of nanocomposites, such as variations in the preparation procedure, the polymer molecular mass and the annealing behaviour of the products are discussed.