Zinc phosphate coating, as an effective and fast anticorrosion technique for the metals, have been developed rapidly in recent years. However, it is still a challenge to synthesize a low energy, environmentally friendly and efficient accelerator through a facile method. Herein, as a new accelerator, polypyrrole (PPy) functionalized graphene oxide (GO-PPy) nanocomposites were prepared by in-situ process to grow PPy film on GO surface, Incorporation of GO-PPy into phosphate baths accelerated the phosphating process of phosphate coating and promoted the nucleation and growth of phosphate crystals, achieving stronger corrosion resistance, which were confirmed by electrochemical measures and morphologies characteristic of the phosphate coating. Additionally, when the concentration of GO-PPy in the phosphate baths reached up 1.2 g/L, the phosphate coating possessed the most compact and uniform phosphate crystals and the best corrosion protection performance. Finally, the special mechanism of the phosphate process was discussed. This work introduces a new, low-energy, facile, environmentally friendly and alternative accelerator for the preparation of phosphate coatings.

The effect of annealing on the electrical and rheological properties of polymer (poly (methyl methacrylate) (PMMA) and polystyrene (PS)) composites filled with carbon black (CB) was investigated. For a composite with CB content near the electrical percolation threshold, the formation of conductive pathways during annealing has a significant impact on electrical conductivity, complex viscosity, storage modulus and loss modulus. For the annealed samples, a reduction in the electrical and rheological percolation threshold was observed. Moreover, a simple model is proposed to explain these behaviors. This finding emphasizes the differences in network formation with respect to electrical or rheological properties as both properties belong to different physical origins.