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Ag nanoparticles-modified 3D graphene foam was synthesized through a one-step in-situ approach and then directly applied as the electrode of an electrochemical sensor. The composite foam electrode exhibited electrocatalytic activity towards Hg(II) oxidation with high limit of detection and sensitivity of 0.11 µM and 8.0 µA/µM, respectively. Moreover, the composite foam electrode for the sensor exhibited high cycling stability, long-term durability and reproducibility. These results were attributed to the unique porous structure of the composite foam electrode, which enabled the surface of Ag nanoparticles modified reduced graphene oxide (Ag NPs modified rGO) foam to become highly accessible to the metal ion and provided more void volume for the reaction with metal ion. This work not only proved that the composite foam has great potential application in heavy metal ions sensors, but also provided a facile method of gram scale synthesis 3D electrode materials based on rGO foam and other electrical active materials for various applications.

In this study, test papers based on N-doped graphene quantum dots and graphene quantum dots were designed and prepared.

The ultrasonic disintegration behavior of polystyrene‐block‐poly(ethylene‐co‐butylenes)‐block‐polystyrene (SEBS) in polypropylene (PP) melts was studied by means of scanning electron microscopy (SEM) and dynamic rheological measurements. A disintegration kinetics model of the dispersed phase in polymer matrix was proposed to explain the ultrasonic disintegration kinetics, and it is in accordance with the equation: dt=d∞+d0−d∞1+Kt. The experimental results showed that the average particle diameter of SEBS decreased with sonication time and approached a limiting value (the equilibrium diameter), below which no further disintegration occurred. The effects of ultrasonic power, ultrasonic frequency, sonication distances, and heating temperatures on the morphology of PP/SEBS blends were also investigated. SEM results demonstrated that the increase of ultrasonic power could enhance the dispersion of SEBS. And SEBS particles were more easily disintegrated at 20 kHz. Moreover, the disintegration extent decreased with the increase of sonication distance or melt temperature. The dispersion state of SEBS was indirectly evaluated by the dynamic rheological properties. It was found that there was an increase in the complex viscosity, storage, and loss moduli as the ultrasonic intensity was in an appropriate scope. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44386.