Polysulfone composites were prepared by solution casting, using various types of treated carbon nanotubes (CNTs) at loadings of up to 5 wt%. The CNT types tested were: as‐received, acid treated, OCA surfactant, OCA functionalized and Poly(methyl methacrylate) functionalized nanotubes prepared using both as‐received and acid treated CNT. The treatment types investigated were selected based upon their solubility parameters and on the results of previous studies. The treated CNTs, CNT/solvent dispersions and the final composite samples were characterised using Fourier Transform Infrared Spectroscopy (FTIR), thermal analysis, Transmission Electron Microscopy (TEM), Ultraviolet‐Visible (UV‐vis) spectroscopy, optical microscopy, electrical conductivity and tensile testing. It was observed that the all the treatments studied improved the stability of CNT in the solvent. Of the CNT types studied, composites containing OCA functionalised CNT displayed the lowest percolation threshold (3 wt%) and highest mechanical performance. While the use of Hildebrand solubility parameters is useful in indentifying promising CNT treatments, their use can not fully predict CNT dispersion behaviour and composite performance. It is also critical to consider the influence of any treatments on CNT length and residual solvent levels. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers

The solution method was used to create polysulfone/carbon nanotubes composites. The effect of three solvents (NMP, DMF, and THF), treatments (nitric acid and ethanol) and surfactants (ODA and OCA) on CNT/ solvent stability was investigated. NMP and DMF resulted in improved stability compared to THF, and all CNT treatments improved stability. Four composites were produced with CNT loadings of 0-5 wt%: as-received CNT and nitric acid treated in THF, as-received CNT and OCA surfactant CNT in NMP. Optical, TEM, and electrical percolation measurements confirmed the role of CNT/solvent stability on the final composite dispersion. Tensile testing and thermal analysis confirmed the presence of residual solvent in all samples.

The fabrication of conductive composite microneedle (MN) patches modified with palladium clusters for the electrocatalytic detection of peroxide is described. Micro molding techniques are utilized in which carbon nanoparticles are bound within a polystyrene matrix resulting in the production of a 10x10 array of needles of length 700 micron. Electrochemical anodization of the carbon particles increases the interfacial carboxyl group population which facilitates the capture of Pd2+ ions. Their subsequent electroreduction yields a catalytic interface with a high sensitivity towards the electroreduction of peroxide (-0.3 V : 49.7+/-2.8 A mM-1 cm-2 ;-0.5 V: 102.1+/-2.32 A mM-1 cm-2). The microneedle sensing system and the various modification stages has been characterized using mechanical testing (fracture testing), cyclic voltammetry and high resolution x-ray photoelectron spectroscopy.

Through-thickness stitching, in the form of tufting, has been shown to be a potentially successful method of improving resistance to delamination. Tufting is a single-sided stitching technique that involves the insertion of a yarn through a fabric, in the z-direction. However, further research into the development of a tailored tufting yarn could yield a greater improvement in the mechanical properties of the overall composite. Unlike other published works which rely on commercially available materials, for this study four thermoplastic yarns were produced from polyetheretherketone, polysulfone, polyethersulfone and polyphenylsulfone. Their ability to be tufted into a composite was examined along with their influence on the overall mechanical properties of the composite.

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