Near-monodisperse, micrometre-sized sterically-stabilized polystyrene (PS) latexes have been coated with polypyrrole-gold (PPy-Au) nanocomposite by in situ deposition of the conducting polymermetal nanocomposite from aqueous solution. Here the pyrrole was oxidized by tetrachloroauric acid, yielding PPy and elementary Au simultaneously. If the poly (N-vinylpyrrolidone) (PNVP)-stabilized PS latex particles are used as seed particles, coagulation occurred before/during PPy-Au nanocomposite deposition. However, if poly (vinyl alcohol) was used as a co-stabilizer in addition to PNVP, colloidally stable nanocomposite-coated PS latex particles were successfully obtained. Pressed pellet conductivity measurements on the dried composite-coated PS particles indicated a conductivity of 4.6 x 10-5 S/cm. IR spectroscopy studies of the composites confirmed the presence of several strong absorption bands due to the PPy. Scanning electron microscopy studies showed rough surface after PPy-Au nanocomposite deposition on the PS seed particles.

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Stress distributions in stepped-lap adhesive joints of similar adherends subjected to static bending moment are analyzed in elastic deformation ranges using three-dimensional finite element method. The effect of the adhesive Young's modulus, the adhesive thickness and the number of steps of adherends on the stress distributions were examined under static bending moment. Using the interface stress distributions obtained from the FEM calculations, the joint strength is estimated. As the result, the maximum value of the maximum principle stress increased as the adhesive Young's modulus and the number of steps was decreased, while the adhesive thickness was increased. For verification of the FEM calculations, experiments to measure the strains of the stepped-lap adhesive joints were carried out using strain gauges. A fairly good agreement was found between the numerical and the measured results concerning the strains. The estimated bending moment when the joint was ruptured was in a fairly good agreement with the measured values.

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