A preliminary study on the effect of macro cavities formation on properties of carbon nanotube bucky-paper composites

In this study, we focus on processing and characterizing composite material structures made of carbon nanotubes (CNTs) and reproducibly engineering macro-pores inside their structure. Highly porous bucky-papers were fabricated from pure carbon nanotubes by dispersing and stabilizing large 1 μm polystyrene beads within a carbon nanotube suspension. The polystyrene beads, homogeneously dispersed across the thickness of the bucky-papers, were then either dissolved or carbonized to generate macro cavities of different shape and properties. The impact of adding these macro cavities on the porosity, specific surface area and Young’s modulus was investigated and some benefits of the macro cavities will be demonstrated.

Dielectric percolative composites with high dielectric constant and low dielectric loss based on sulfonated poly(aryl ether ketone) and a-MWCNTs coated with polyaniline

Acidified multi-walled carbon nanotubes (a-MWCNTs) coated with polyaniline (PANI) (a-MWCNTs@PANI) nanofiller were prepared by in situ polymerization. Novel dielectric percolative composites, sulfonated poly(aryl ether ketone) (SPAEK)/a-MWCNTs@PANI, with high dielectric constant and low dielectric loss were fabricated using simple solution blending technique. A SPAEK/a-MWCNTs@PANI composite prepared in this fashion exhibited a high dielectric constant above 800, a dielectric loss tangent less than 1.1 at 10 kHz and room temperature. The morphological study of composites by SEM suggested that the in situ polymerization method of preparing a-MWCNTs@PANI nanofillers was useful to achieve good dispersion of fillers in SPAEK matrix.

Novel polymer-ceramic composites for protection against ballistic fragments

For the first time, internally reinforced aggregate polymer ceramic composites were evaluated against fragment simulating projectiles (FSPs) of various calibers to investigate their ballistic impact response. Samples were prepared by mechanically mixing B4C and cBN over a range of ratios and combinations with either thermosetting phenolic or epoxy resin and aramid pulp. Dry mixtures were then molded in a closed die using a heated platen press. The resulting tiles were then mounted as ‘‘strike faces’’ to an aramid backing material using an epoxy resin. Backed targets were tested in a fully instrumented firing range against 5.56 mm FSPs to test ballistic limit. A further series of tests using 7.62, 12.5, and 20 mm FSPs was conducted to examine round deformation across a range of fragments calibers. Round deformations were measured after impact and plotted against shot velocity. It was found that the polymer ceramic composite materials were effective round deformers and, like sintered ceramic strike faces, demonstrated improved ballistic performance at an equivalent areal density and impressive multihit capability.

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.