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The aim of this study is to investigate the possibility of using a polymer material, polyvinyl alcohol (PVA), as an additional carbon source to fabricate carbon nanotubes using arc-discharge method. Experiments were carried out using a graphite anode filled with a mixture of PVA and iron group catalysts. The results indicated that PVA material not only can be used for the formation of carbon nanotubes but also for the formation of some novel carbonaceous structures such as spherical nanoparticles, beaded and sheet-like carbon nanostructures. Furthermore, we found that the catalyst content in the PVA filling mixture should be lower than 50 wt%. In addition, novel catalyst precursors, such as Fe2(SO4)3 · nH2O or Fe(NO3)3 · 9H2O, were employed to grow carbon nanotubes. The results showed that these catalyst precursors can be used to form carbon nanotubes if their filling content does not exceed 50 wt%. [Copyright &y& Elsevier]

Highlights: [•] Surface modification of AlN by ceramic coating method. [•] A good compatibility between amorphous SiOC ceramic film coated AlN and silicone rubber composite. [•] Effect of the morphology of PSZ and SiOC films as intermediate layer on the thermal conductivity of the composite. [ABSTRACT FROM AUTHOR]

In this study, we used a LUMiSizer® analytical centrifuge to determine the particle dispersions and size distributions of organic/inorganic composite coatings. The centrifuge was capable of recording both the measure space and time-resolved extinction profiles (STEP™-Technology) for up to 12 samples simultaneously, making it a powerful tool for the characterization and quality control of coatings. While the variation of the light extinction curves after centrifugal segregation provided a qualitative description, a rigorous formulation can provide detailed quantitative characterization. The technique used in this study allowed demixing to be accelerated and direct quantification of the dispersibility of the coatings. Because the dispersants and binders stabilized the organic/inorganic composite coatings, the dispersibility strongly depended on their concentration. The dispersibility of the coatings increased upon increasing the dispersant concentration and decreasing the concentration of the binder. Furthermore, the inorganic particles exhibited good dispersibility, without large degrees of aggregation, in the coating dispersions. We also used the LUMiSizer® to determine the particle size distribution and shelf life of coatings; the results were comparable with those obtained using dynamic light scattering, scanning electron microscope and zeta potential analysis. [ABSTRACT FROM AUTHOR]