Designing 3D graphene networks via a 3D-printed Ni template

Copyright © Royal Society of Chemistry 2015It is highly desirable to design and control the properties of 3D graphene networks with preferred shapes, lengths, diameters of the trusses so as to add new functionalities. Hereby, we demonstrate a conceptual design and the practical synthesis of periodic 3D graphene networks via CVD using a 3D-printed Ni scaffold as the template.Natural Science foundation of Heilongjiang province of ChinaEU/FP

A generic method to synthesise graphitic carbon coated nanoparticles in large scale and their derivative polymer nanocomposites

A versatile Rotary Chemical Vapour Deposition (RCVD) technique for the in-situ synthesis of large scale carbon-coated non-magnetic metal oxide nanoparticles (NPs) is presented, and a controllable coating thickness varying between 1–5 nm has been achieved. The technique has significantly up-scaled the traditional chemical vapour deposition (CVD) production for NPs from mg level to 10 s of grams per batch, with the potential for continuous manufacturing. The resulting smooth and uniform C-coatings sheathing the inner core metal oxide NPs are made of well-crystallised graphitic layers, as confirmed by electron microscopy imaging, electron dispersive spectrum elemental line scan, X-ray powder diffractions and Raman spectroscopy. Using nylon 12 as an example matrix, we further demonstrate that the inclusion of C-coated composite NPs into the matrix improves the thermal conductivity, from 0.205 W∙m−1∙K−1 for neat nylon 12 to 0.305 W∙m−1∙K−1 for a 4 wt% C-coated ZnO composite, in addition to a 27% improvement in tensile strength at 2 wt% addition

How the toughest inorganic fullerene cages absorb shockwave pressures in a protective nanocomposite: experimental evidence from two in situ investigations

Nanocomposites fabricated using the toughest caged inorganic fullerene WS2 (IF-WS2) nanoparticles could offer ultimate protection via absorbing shockwaves; however, if the IF-WS2 nanomaterials really work, how they behave and what they experience within the nanocomposites at the right moment of impact have never been investigated effectively, due to the limitations of existing investigation techniques that are unable to elucidate the true characteristics of high-speed impacts in composites. We first fabricated Al matrix model nanocomposites and then unlocked the exact roles of IF-WS2 in it at the exact moment of impact, at a time resolution that has never been attempted before, using two in situ techniques. We find that the presence of IF-WS2 reduced the impact velocity by over 100 m/s and in pressure by at least 2 GPa against those Al and hexagonal WS2 platelet composites at an impact speed of 1000 m/s. The IF-WS2 composites achieved an intriguing inelastic impact and outperformed other reference composites, all originating from the “balloon effect” by absorbing the shockwave pressures. This study not only provides fundamental understanding for the dynamic performance of composites but also benefits the development of protective nanocomposite engineering

Meso/microporous carbon materials : syntheses, characterisation and applications

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Preparation of 3D graphene-based architectures and their applications in supercapacitors

ArticleThree dimensional (3D) graphene-based architectures such as 3D graphene-based hydrogels, aerogels, foams, and sponges have attracted huge attention owing to the combination of the structural interconnectivities and the outstanding properties of graphene which offer these interesting structures with low density, high porosity, large surface area, stable mechanical properties, fast mass and electron transport. They have been extensively studied for a wide range of applications including capacitors, batteries, sensors, catalyst, etc. There are several reviews focusing on the 3D graphene-based architectures and their applications. In this work, we only summarise the latest development on the preparation of 3D graphene-based architectures and their applications in supercapacitors, with emphasis on the preparation strategies

Three dimensional (3D) flexible graphene foam/polypyrrole composite: towards highly efficient supercapacitors

Polypyrrole (PPY) functionalized 3 dimensional (3D) graphene foam (GF) with remarkable electrochemical performance has been synthesized in this work. The resulting 3D PPY–GF electrode is free standing and hence was used directly as a working electrode without using any binder or carbon additives. The unique features of the PPY–GF composites such as their hierarchically flexible 3D network, and high conductivity of p-doped PPY, afforded PPY–GF electrodes with enhanced pseudocapacitive properties. Under optimal conditions, a maximum specific capacitance of 660 F g−1, specific energy of 71 W h kg−1, comparable to battery performance, and a specific power of 2.4 kW kg−1 (at 0.5 mA) were obtained. Both GF and PPY–GF electrodes exhibited an excellent cycle life and retained almost 100% of their initial capacitances after 10 000 and 6000 charge–discharge cycles, respectively. This highly enhanced stability is attributed to the significant impact of the GF density on the flexibility of the electrode, and the hierarchical pore structures which provided short effective pathways for ion and charge transport and stayed unchanged after thousands of cycles. The PPY–GF pore size varies from a few nm for small pores to a hundred μm for macropores

Performance Investigation of Single–Piston Free Piston Expander–Linear Generator with Multi–Parameter Based on Simulation Model

The structural design and operating strategy of a free piston expander–linear generator (FPE–LG) has a major impact on performance. In this paper, the simulation model of single–piston FPE–LG was built and verified by combining the structural parameters of the existing test rig with a set of kinetic and thermodynamic equations. On this basis, the influence of the design and operating parameters of the device on the performance was studied, while keeping other parameters fixed. Then, a sensitivity analysis of power output and operating frequency was carried out. The results show that within a certain range of external load and intake beginning position, increasing the diameter of the intake and exhaust pipes, or reducing the piston rod diameter can improve the power output. Within a certain range of frictional coefficient and intake time, increasing the cylinder diameter and intake pressure, or reducing the piston assembly mass and back electromotive force (EMF) constant can increase the operating frequency. Both the power output and the operating frequency are most sensitive to the cylinder diameter among the design parameters. Among the operating parameters, power output is the most sensitive to intake pressure, and operating frequency is the most sensitive to intake beginning position. The optimization of structural design and operation strategy in expander provides important guiding significance for ORC waste heat recovery system