Poly(ethylene oxide) (PEO)–clay (montmorillonite, hectorite, and laponite) nanocomposites were prepared by a melting intercalation procedure induced by microwave irradiation. The influence of parameters such as the time of irradiation, power, amount and relative ratio of the reagents, and relative humidity was investigated. X‐ray diffraction, differential scanning calorimetry, elemental microanalysis, Fourier transform infrared, and scanning electron microscopy techniques were applied to characterize the resulting nanocomposites. Techniques involving impedance spectroscopy, thermoelectric power, and electrical polarization in the solid state were used to characterize the electrical properties of the nanocomposites. The electrical behavior of these PEO–silicate nanocomposites, including those containing an excess of alkaline metal salts in comparison with that of similar systems prepared by alternative procedures such as direct intercalation from polymer solutions or melting intercalation, was also examined. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 3249–3263, 2003

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Carbons from cane molasses with 8 m2 g−1 BET area yielded capacitances up to 153 F g−1 at 0.5 mV s−1 in 1 M H2SO4, with 35.2% pseudocapacitance contribution, due to the high surface concentration of quinone and carbonyl groups.

An analytical method was developed for the determination of three major (Li, Ni and Co) and fourteen minor or trace elements (Al, Ba, Ca, Cu, Cr, Fe, K, Mg, Mn, Na, Si, Sr, Ti and V) in LiNi1-xCoxO2 (x=0.2-0.8) ceramic powders by inductively coupled plasma optical emission spectrometry. Sample dissolution was achieved by 25% nitric acid digestion in a microwave oven. For each element, an analytical line free from spectral interferences was selected. A detailed study of matrix effects over a wide interval of total excitation energy (TEE) lines (1.62-16.50 eV) was performed at near-robust plasma conditions. A remarkable enhancement in atomic lines with TEE<4 eV was noticed, whereas a significant reduction in atomic and ionic lines with TEE>4 eV was observed. The extrapolation to infinite dilution method was successfully used to overcome these nonspectroscopic interferences. Detection limits (3sigma) varied from 0.21 mg kg-1 for Sr to 49.7 mg kg-1 for Na. The precision of determination (obtained as the relative standard deviation) was lower than 1% for the major elements Li, Ni and Co and between 0.69 and 10% for minor and trace elements. The accuracy of the method ranged from 91 to 101% for major elements, and from 90 to 110%, or close to this range, for most of the impurities in both of the samples studied.