Miniaturization of conventional energy sources has so far proven to be a cumbersome process. A recently developed concept of thermopower waves has shown tremendous potential to reduce the dimensions of power sources while maintaining their energy generation capabilities. We demonstrate a tremendous improvement in the output for these thermopower wave-based energy generation devices by implementing manganese dioxide (MnO 2 ) as the core thermoelectric material. In this work, the thermoelectric MnO 2 layer is used as a pathway for the propagation of thermopower waves that are generated as a result of an exothermic chemical reaction of a solid fuel (nitrocellulose). Such selfpropagating thermopower waves result in exceptionally high voltage output on the order of 1.8 V and a specific power (power-tomass ratio) on the order of 1.0 kW•kg −1 . The output voltage is at least 300% higher than any other thermopower wave system reported so far.

Abstract. Polypropylene (PP) nanocomposites were obtained by solution blending of polyether treated montmorillonite and PP, with a coupling agent of maleic anhydride grafted polypropylene (PP-g-MA). The composition of the inorganic clay was varied in 1, 2 and 5 phr (parts of clay per hundred of PP by mass) while films of the composites were obtained via compression molding. Wide-angle X-ray scattering (WAXS) showed nanocomposites in which silicate layers were exfoliated and intercalated with respect to the different clay ratios. The morphology and gas permeability of hybrids prepared with organoclay were compared. Morphological studies using transmission electron microscopy showed most clay layers were dispersed uniformly in the PP matrix. Some tactoids of agglomerated nanoparticles were detected, as clay content increased. The oxygen permeability for all the hybrids for clay loadings were reduced by 30% of the corresponding values for pure PP.

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The non-covalent interaction of acetylated nanocrystalline cellulose (AC-NCC) with polylactic acid (PLA) in a composite blend has been studied at the micron scale by synchrotron Fourier Transform Infrared (FTIR) microspectroscopy. Microtomed sections of AC-NCC in PLA showed strong, localized carbonyl stretching (νC=O) absorbance characteristic of the cellulose acetylation, and this was observed on the surface of larger aggregated AC-NCC particles. A shift in the νC=O IR absorption peak of AC-NCC in PLA, relative to unblended AC-NCC was observed, which is indicative of an intermolecular interaction between AC-NCC and PLA matrix. Acetylation can therefore potentially improve the performance of the composite by enabling linkages between carbonyl groups, helping to establish a good stress transfer between the fiber and the matrix. This could in turn lead to a material with high yield elastic modulus. This is the first reported chemical imaging of acetylated nanocrystalline cellulose-based composite materials using synchrotron FTIR microspectroscopy.

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In the present study, the thermongravimetric analysis (TGA) of laboratory hardwood and softwood particleboard was studied. The TGA showed that both hardwood and softwood have similar thermal behaviour at the same peak temperature. However, softwood is concluded to have higher fire retardancy as more char formation happened in softwood. A further study was carried out to compare the thermal behaviour of laboratory manufactured boards with the commercial grade boards. Superior thermal stability of commercial particleboard had confirmed its effective crosslinking and wood-resin adhesion.