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The effect of varying preparation conditions on the properties of buckypapers made using single-walled carbon nanotubes (SWNTs) was systematically investigated. Changing the sonication time, final dispersion volume or membrane filter used to prepare SWNT-Triton X-100 buckypapers all generally had only a small influence on the density, thickness, contact angle and electrical conductivity of the resulting material. More significant changes were noted when the effects of variations in the above preparation conditions on the mechanical properties and surface morphology of SWNT-Triton X-100 buckypapers were investigated. However, the largest changes in properties were found when various biopolymers (bovine serum albumin, lysozyme, gellan gum and chitosan) were used instead of Triton X-100 to prepare dispersions from which the buckypapers were made. It was observed that the electrical conductivity of the buckypapers decreased as the molecular mass of the biopolymer dispersant used increased, whereas the mechanical properties of the materials showed significant improvements.

The crystal structure of the bicyclic hexaamine complex [Cu(fac-Me 5-tricosane-N6)](ClO4)2· H2O (fac-Me5-tricosane-N6 = facial-1,5,9,13,20-pentamethyl-3,7,11,15,18,22-hexaazabicyclo[7.7.7]tricosane) at 100 K defines an apparently tetragonally compressed

The recovery of platinum from solutions containing [PtCl6]2− using inherently conducting polymer (ICP) powders, membranes and coated fabrics has been investigated. Polyaniline (PAn) powders were able to recover platinum from solution, whereas polypyrrole (PPy) powders and membranes displayed almost no ability to perform this task. Uncoated pieces of nylon and nylon-lycra showed a significant capacity to recover platinum metal, unlike each of the other common fabrics investigated. Surprisingly the amount of platinum recovered by nylon-lycra was not improved by coating the fabric with a layer of ICP. Pieces of nylon-lycra that had previously been soaked in solutions containing [PtCl6]2− released only a small percentage of the bound metal when treated with 5 % HCl. However, subsequent treatment with aqua regia released all of the remaining platinum. A mechanism of platinum recovery by nylon and nylon-lycra involving coordination to functional groups present in their polymeric structures is proposed.

Aqueous solutions containing pyrrole and calix-6-arenehexasulfonic acid were found to undergo polymerization in the absence of either a chemical oxidant or electrochemical oxidation. The product was an unstable colloidal suspension consisting of spherical polypyrrole particles measuring ≥500 nm in diameter. Conductivity measurements showed the material to be insulating, while cyclic voltammetry studies demonstrated that it was electroactive. Infrared spectroscopy and microanalysis confirmed that the polypyrrole produced was doped with calix-6-arenehexasulfonic acid. When the reaction was repeated using solutions containing stabilizing agents, stable colloidal dispersions were obtained. These were shown by both particle size analysis and transmission electron microscopy to contain much smaller particles than the unstabilized material, while cyclic voltammetry studies again demonstrated that the polypyrrole obtained was electroactive and sensitive to changes in the surrounding electrolyte.

Conducting polymers deposited onto reticulated vitreous carbon (RVC) were shown to remove gold from aqueous solutions in a facile and highly efficient fashion. For acidic solutions with initial [AuCl4]- concentrations between 0.1 and 1000 ppm, gold recoveries >90% were obtained. Experiments, conducted using solutions containing 0.1 ppm [AuCl4]-, also demonstrated that the composite materials were significantly more effective at recovering gold than activated carbon. Gold removal from solutions containing [AuCl4]- and much higher concentrations of iron was highly selective.

Conducting polymer coated fabrics were found to recover gold from solutions contammg [AuC14]- in a facile and selective fashion. Although the fabric substrates also demonstrated a significant ability to recover gold, the rate of uptake by the coated fabrics was significantly faster. Conducting polymer coated fabrics also recovered gold from solutions containing [Au(CN)2]-, however, little selectivity was observed when solutions containing both gold and copper cyanide complexes were examined.

Removal of gold from basic solutions containing [Au(CN)2]- has been demonstrated using the inherently conducting polymer polypyrrole. Polymers containing sulfonated aromatic dopants have been found to display a significant ability to remove gold from such solutions. Experiments performed in solutions containing both gold and copper cyanide complexes indicate that the recovery process is not highly selective. However, the polypyrroles used display significantly faster rates of gold recovery than activated carbon.

ESI mass spectra show that up to five ruthenium molecules can bind non-covalently to double stranded 16mer DNA, and provide information on the relative affinity and DNA sequence selectivity of different ruthenium complexes.

Electrochemically controlled transport of copper and iron across composite membranes containing polypyrrole (PPy) doped with either 8-hydroxyquinoline-5-sulfonic acid (HQS) or 2,9-dimethyl-4. 7-diphenyl-l, 1 O-phenanthrolinedisulfonic acid (BCS) is described. The flux of copper across composite Pl'yIBCS membranes was greater than that for iron. and almost 50 times greater than the largest value previously reported for copper transport across a conducting polymer membrane. Composite membranes containing PPy/HQS allwed transport of copper ions but proved completely impermeable to iron transport.

A variety of metal ions including alkali metals and transition metals can he transported across conducting polymer membranes, but only when an appropriate electrochemical stimulus is applied. This paper summarizes recent work in this area, and also describes how conducting polymer RVC composite materials (RVC = reticulated vitreous carbon) can be used to recover gold from solutions containing [AuCl4] with a high degree of efficiency and selectivity.