Fabrication of nano-particle reinforced metal matrix composites

Nanoparticle reinforced metal matrix possess much better mechanical properties over microparticle reinforced metal matrix composites as well as corresponding monolithic matrix materials. However, the fabrication methods of nanoparticle reinforced metal matrix composites are complex and expensive. This paper investigates and discusses the mechanisms of all the fabrication process, such as powder metallurgy, liquid metallurgy, compocasting and hybrid methods, available in the literature. This gives an insight on challenges associated with different processes and ways to improve the fabrication processes. It is found that modified traditional fabrication processes are mainly applied for these materials. The main problem is to achieve reasonably uniform distribution of nanoparticle reinforcement in the methods other than mechanical alloying when the volume or weight percent of reinforcement is higher (> 1%).

Facile fabrication of polyolefin/carbon nanotube composites via in situ friedel-crafts polyalkylation : structure and properties

Despite major advances in addressing the dispersion of carbon nanotubes (CNTs) in polymers and their interfacial interactions, exploring a facile approach for massively creating them is still fascinating. We interestingly find that the CNT dispersion is considerably improved in polypropylene (PP), and ?19.1 wt % of PP chains were in situ chemically grafted onto CNT surfaces only using a trace of AlCl3 via a one-step melt-blending. Compared with the PP/CNT composite, adding 0.2 wt % of AlCl3 enables an increase in tensile strength and Young's modulus of 30% and 25%, respectively. Moreover, the elongation at break is almost maintained, while adding CNTs alone causes significant decreases. Additionally, 0.2 wt % AlCl3 makes the thermal degradation temperature further improved. These remarkable improvements in properties are mainly attributed to better dispersion of CNTs and enhanced interfacial compatibility. This work opens up an innovative approach for scalable preparation of polyolefin/CNT composites applying to industrial production.

Carbon Nanotube – Reduced Graphene Oxide Composites for Thermal Energy Harvesting Applications

By controlling the SWNT-rGO electrode composition and thickness to attain the appropriate porosity and tortuosity, the electroactive surface area is maximized while rapid diffusion of the electrolyte through the electrode is maintained. This leads to an increase in exchange current density between the electrode and electrolyte which results in enhanced thermocell performance.

Plasma functionalization of nanotubes and carbon fibres for application in composites

During his PhD studies, Zhiqiang published 5 journal paper and 7 conference paper and also participated in the development of the first Plasma Research Laboratory at Institute of Frontier Materials.

Cellulose-based biodegradable blends and composites regenerated from ionic liquids

This thesis presents the fabrication of biodegradable polymer blends and composites with the assistance of ionic liquids. The work included preparation and characterization of cellulose/PCL blend films, cellulose/ PCL-PDMS-PCL blend films, cellulose/ PVAL blend films and cellulose/clay composite films. An efficient and feasible approach of reducing plastic pollution was developed.

Improved fracture toughness of fire resistant composites through rapid curing

A study on the effect of material and fracture properties of phenolic composites cured with reduced thermal cycle times. These reductions were achieved using various techniques. The work highlights significant reductions in manufacturing times are possible for this group of materials and conveniently can also lead to improved properties.

Bi-functional oxygen electrocatalysts based on Palladium oxide-Ruthenium oxide composites

Bi-functional oxygen electrodes are an enabling component for rechargeable metal-air batteries and regenerative fuel cells, both of which are regarded as the next-generation energy devices with zero emission. Nonetheless, at the present, no single metal oxide component can catalyze both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with high performance which leads to large overpotential between ORR and OER. This work strives to address this limitation by studying the bi-functional electrocatalytic activity of the composite of a good ORR catalyst compound (e.g. palladium oxide, PdO) and a good OER catalyst compound (e.g. ruthenium oxide, RuO2) in alkaline solution (0.1M KOH) utilizing a thin-film rotating disk electrode technique. The studied compositions include PdO, RuO2, PdO/RuO2 (25wt.%/75wt.%), PdO/RuO2 (50wt.%/50wt.%) and PdO/RuO2 (75wt.%/25wt.%). The lowest overpotential (e.g. E (2 mA cm−2) - E (-2 mA cm−2)) of 0.82 V is obtained for PdO/RuO2 (25wt.%/75wt.%) (versus Ag|AgCl (3M NaCl) reference electrode).