Nanotechnology Solutions for Global Water Challenges

The lack of clean and safe drinking water is responsible for more deaths than war, terrorism and weapons of mass destruction combined. This suggests contaminated water poses a significant threat to human health and welfare. In addition, standard water disinfection approaches such as sedimentation, filtration, and chemical or biological degradation are not fully capable of destroying emerging contaminants (e.g. pesticides, pharmaceutical waste products) or certain types of bacteria (e.g. Cryptosporidium parvum). Nanomaterials and nanotechnology based devices can potentially be employed to solve the challenges posed by various contaminants and microorganisms. Nanomaterials of different shapes, namely nanoparticles, nanotubes, nanowires and fibers have the ability to function as adsorbents and catalysts. These possess an expansive array of physicochemical characteristics deeming them highly attractive for the production of reactive media for water membrane filtration, a vital step in the production of potable water. As a result of their exceptional adsorptive capacity for water contaminants, graphene based nanomaterials have emerged as an area of significant importance in the area of membrane filtration and water treatment. In addition, Advanced Oxidation Processes (AOPs) together with or without sources of light irradiation or ultrasound, have been found to be promising alternatives for water treatment at near ambient temperature and pressure. Furthermore, the uses of visible light active titanium dioxide photocatalysts and photo-Fenton processes have shown significant potential for water purification. A wide variety of nanomaterial based sensors, for the monitoring of water quality, have also been reviewed in detail. In conclusion, the rapid and continued growth in the area of nanomaterial based devices offers significant hope for addressing future water quality challenges

Synthesis and Characterisation of N-substituted Pyrrole Monomers and Polypyrrole Films

In this body of work, the polymerisation of N-substituted pyrrole monomers and the functionalisation of the monomers or the resulting polymers, with transition metal complexes, were performed. Polymer deposition was executed, utilising the electrochemical deposition technique, due to its facile use and the unequivocal control attained during the experimental procedure. The pyrrole monomers employed, possessed either azide, 2,2’-bipyridine or nitrile moieties, as these species have been universally exploited in cycloaddition and coordination chemistry. Firstly, N-(10-azidodecyl)pyrrole, N-(3-azidopropyl)pyrrole and N-(2- azidoethyl)pyrrole were electropolymerised in the bulk morphology and characterised. Then, employing copper(I)-catalysed azide-alkyne cycloaddition chemistry, the monomers, N-(10-azidodecyl)pyrrole and N-(2-azidoethyl)pyrrole, were reacted with the redox active molecule, ethynylferrocene, to yield the products, 1-[10-(4-ferrocenyl-1H-1,2,3-triazol-1yl)decyl]pyrrole and 1-[2-(4-ferrocenyl-1H�1,2,3-triazol-1yl)ethyl]pyrrole, which were subsequently electropolymerised and characterised. Development of a novel, template-free, electrodeposition method yielded the facile fabrication of the nanostructured poly[N-(2-azidoethyl)pyrrole] film, shown using field emission scanning electron microscopy and transmission electron microscopy. The deposition mechanism, involving a bielectrolyte co-solvent system, was investigated using nucleation and growth mechanisms, while the roles of both the ‘seed’ (LiClO4) and ‘bulk’ ((NH4)H2PO4) electrolyte were determined. Chemical post-functionalisation of the nanowire film, via copper(I)-catalysed azide-alkyne cycloaddition chemistry, permitted the covalent attachment of ethynylferrocene, which created the possibility of a very effective, mediator-less (covalently bound), nanostructured biosensor. A novel pyrrole monomer, 4,4’-bis-(N-propyl-3-pyrrole-carbamoyl)-2,2’-bipyridine was synthesised and coordinated with Group 6 metal carbonyls, producing 4,4’-bis- (N-propyl-3-pyrrole-carbamoyl)-2,2’-bipyridine tetracarbonyl chromium(0), molybdenum(0) and tungsten(0). The electroactivity of 4,4’-bis-(N-propyl-3-pyrrole�carbamoyl)-2,2’-bipyridine tetracarbonyl molybdenum(0) was determined utilising cyclic voltammetry, while the controlled release of carbon monoxide was induced by introducing acetonitrile. The 4,4’-bis-(N-propyl-3-pyrrole-carbamoyl)-2,2’- bipyridine ligand was electropolymerised and post-functionalisation with Group 6 metal carbonyls was attempted, to possibly produce medically beneficial carbon monoxide releasing polymers. Utilising the nitrile moiety, tricarbonyl cyclopentadienyl N-2-(5-tetrazolatephenyl) molybdenum(II), tricarbonyl cyclopentadienyl N-2-(5-tetrazolate-2-thiophene) molybdenum(II) and tricarbonyl cyclopentadienyl N-2-(5-tetrazolate-1-benzyl) molybdenum(II) were synthesised via cycloaddition chemistry employing sodium azide. N-(2-cyanoethyl)pyrrole, possessing the ability to be electrodeposited as a nanostructured film was employed, producing dicarbonyl cyclopentadienyl (N-2-(5- tetrazolate-2-ethylpyrrole) iron(II)

Synthesis and Characterisation of N-substituted Pyrrole Monomers and Polypyrrole Films

In this body of work, the polymerisation of N-substituted pyrrole monomers and the functionalisation of the monomers or the resulting polymers, with transition metal complexes, were performed. Polymer deposition was executed, utilising the electrochemical deposition technique, due to its facile use and the unequivocal control attained during the experimental procedure. The pyrrole monomers employed, possessed either azide, 2,2’-bipyridine or nitrile moieties, as these species have been universally exploited in cycloaddition and coordination chemistry. Firstly, N-(10-azidodecyl)pyrrole, N-(3-azidopropyl)pyrrole and N-(2- azidoethyl)pyrrole were electropolymerised in the bulk morphology and characterised. Then, employing copper(I)-catalysed azide-alkyne cycloaddition chemistry, the monomers, N-(10-azidodecyl)pyrrole and N-(2-azidoethyl)pyrrole, were reacted with the redox active molecule, ethynylferrocene, to yield the products, 1-[10-(4-ferrocenyl-1H-1,2,3-triazol-1yl)decyl]pyrrole and 1-[2-(4-ferrocenyl-1H�1,2,3-triazol-1yl)ethyl]pyrrole, which were subsequently electropolymerised and characterised. Development of a novel, template-free, electrodeposition method yielded the facile fabrication of the nanostructured poly[N-(2-azidoethyl)pyrrole] film, shown using field emission scanning electron microscopy and transmission electron microscopy. The deposition mechanism, involving a bielectrolyte co-solvent system, was investigated using nucleation and growth mechanisms, while the roles of both the ‘seed’ (LiClO4) and ‘bulk’ ((NH4)H2PO4) electrolyte were determined. Chemical post-functionalisation of the nanowire film, via copper(I)-catalysed azide-alkyne cycloaddition chemistry, permitted the covalent attachment of ethynylferrocene, which created the possibility of a very effective, mediator-less (covalently bound), nanostructured biosensor. A novel pyrrole monomer, 4,4’-bis-(N-propyl-3-pyrrole-carbamoyl)-2,2’-bipyridine was synthesised and coordinated with Group 6 metal carbonyls, producing 4,4’-bis- (N-propyl-3-pyrrole-carbamoyl)-2,2’-bipyridine tetracarbonyl chromium(0), molybdenum(0) and tungsten(0). The electroactivity of 4,4’-bis-(N-propyl-3-pyrrole�carbamoyl)-2,2’-bipyridine tetracarbonyl molybdenum(0) was determined utilising cyclic voltammetry, while the controlled release of carbon monoxide was induced by introducing acetonitrile. The 4,4’-bis-(N-propyl-3-pyrrole-carbamoyl)-2,2’- bipyridine ligand was electropolymerised and post-functionalisation with Group 6 metal carbonyls was attempted, to possibly produce medically beneficial carbon monoxide releasing polymers. Utilising the nitrile moiety, tricarbonyl cyclopentadienyl N-2-(5-tetrazolatephenyl) molybdenum(II), tricarbonyl cyclopentadienyl N-2-(5-tetrazolate-2-thiophene) molybdenum(II) and tricarbonyl cyclopentadienyl N-2-(5-tetrazolate-1-benzyl) molybdenum(II) were synthesised via cycloaddition chemistry employing sodium azide. N-(2-cyanoethyl)pyrrole, possessing the ability to be electrodeposited as a nanostructured film was employed, producing dicarbonyl cyclopentadienyl (N-2-(5- tetrazolate-2-ethylpyrrole) iron(II)

Synthesis and Characterisation of N-substituted Pyrrole Monomers and Polypyrrole Films

In this body of work, the polymerisation of N-substituted pyrrole monomers and the functionalisation of the monomers or the resulting polymers, with transition metal complexes, were performed. Polymer deposition was executed, utilising the electrochemical deposition technique, due to its facile use and the unequivocal control attained during the experimental procedure. The pyrrole monomers employed, possessed either azide, 2,2’-bipyridine or nitrile moieties, as these species have been universally exploited in cycloaddition and coordination chemistry. Firstly, N-(10-azidodecyl)pyrrole, N-(3-azidopropyl)pyrrole and N-(2- azidoethyl)pyrrole were electropolymerised in the bulk morphology and characterised. Then, employing copper(I)-catalysed azide-alkyne cycloaddition chemistry, the monomers, N-(10-azidodecyl)pyrrole and N-(2-azidoethyl)pyrrole, were reacted with the redox active molecule, ethynylferrocene, to yield the products, 1-[10-(4-ferrocenyl-1H-1,2,3-triazol-1yl)decyl]pyrrole and 1-[2-(4-ferrocenyl-1H�1,2,3-triazol-1yl)ethyl]pyrrole, which were subsequently electropolymerised and characterised. Development of a novel, template-free, electrodeposition method yielded the facile fabrication of the nanostructured poly[N-(2-azidoethyl)pyrrole] film, shown using field emission scanning electron microscopy and transmission electron microscopy. The deposition mechanism, involving a bielectrolyte co-solvent system, was investigated using nucleation and growth mechanisms, while the roles of both the ‘seed’ (LiClO4) and ‘bulk’ ((NH4)H2PO4) electrolyte were determined. Chemical post-functionalisation of the nanowire film, via copper(I)-catalysed azide-alkyne cycloaddition chemistry, permitted the covalent attachment of ethynylferrocene, which created the possibility of a very effective, mediator-less (covalently bound), nanostructured biosensor. A novel pyrrole monomer, 4,4’-bis-(N-propyl-3-pyrrole-carbamoyl)-2,2’-bipyridine was synthesised and coordinated with Group 6 metal carbonyls, producing 4,4’-bis- (N-propyl-3-pyrrole-carbamoyl)-2,2’-bipyridine tetracarbonyl chromium(0), molybdenum(0) and tungsten(0). The electroactivity of 4,4’-bis-(N-propyl-3-pyrrole�carbamoyl)-2,2’-bipyridine tetracarbonyl molybdenum(0) was determined utilising cyclic voltammetry, while the controlled release of carbon monoxide was induced by introducing acetonitrile. The 4,4’-bis-(N-propyl-3-pyrrole-carbamoyl)-2,2’- bipyridine ligand was electropolymerised and post-functionalisation with Group 6 metal carbonyls was attempted, to possibly produce medically beneficial carbon monoxide releasing polymers. Utilising the nitrile moiety, tricarbonyl cyclopentadienyl N-2-(5-tetrazolatephenyl) molybdenum(II), tricarbonyl cyclopentadienyl N-2-(5-tetrazolate-2-thiophene) molybdenum(II) and tricarbonyl cyclopentadienyl N-2-(5-tetrazolate-1-benzyl) molybdenum(II) were synthesised via cycloaddition chemistry employing sodium azide. N-(2-cyanoethyl)pyrrole, possessing the ability to be electrodeposited as a nanostructured film was employed, producing dicarbonyl cyclopentadienyl (N-2-(5- tetrazolate-2-ethylpyrrole) iron(II)

Facile template-free electrochemical preparation of poly[N-(2-cyanoethyl)pyrrole] nanowires

In this paper the first synthesis of poly[N-(2-cyanoethyl)pyrrole] (PPyEtCN) in a nanowire morphology is reported. The method employed is a facile, one step electrochemical growth, which does not require the use of any templates or surfactants. Using optimised conditions the nanowires nucleate to give a homogeneous film across the electrode surface, with lengths of approximately 2 μm and diameters of approximately 150 nm. Structural information on the nanowires was obtained using vibrational spectroscopy. Evidence is presented to support an instantaneous 3-D nucleation and growth mechanism for the nanowires

Electrochemical Deposition of Hollow N‑Substituted Polypyrrole Microtubes from an Acoustically Formed Emulsion

We outline an electrodeposition procedure from an emulsion to fabricate novel vertically aligned open and closed-pore microstructures of poly(N-(2-cyanoethyl)pyrrole) (PPyEtCN) at an electrode surface. Adsorbed toluene droplets were employed as soft templates to direct polymer growth. The microstructures developed only in the presence of both ClO4– and H2PO4– doping ions due to a slower rate of polymer propagation in this electrolyte. Two sonication methods (probe and bath) were used to form the emulsion, producing significantly different microstructure morphologies. Control over microtube diameter can be achieved by simply altering the emulsion sonication time or the amount of toluene added to form the emulsion. Electrochemical characterization indicated the PPyEtCN microtube morphology had an increased electrochemical response compared to its bulk counterpart. TEM analysis of individual closed-pore microtubes identified a hollow interior at the base within which the toluene droplet was encapsulated. This cavity may be used to entrap other compounds making these materials useful in a range of applications. The methodology was also applied to form microstructures of poly(3,4-ethylenedioxythiophene) and polypyrrole

Electrochemical Deposition of Hollow N‑Substituted Polypyrrole Microtubes from an Acoustically Formed Emulsion

We outline an electrodeposition procedure from an emulsion to fabricate novel vertically aligned open and closed-pore microstructures of poly­(<i>N</i>-(2-cyanoethyl)­pyrrole) (PPyEtCN) at an electrode surface. Adsorbed toluene droplets were employed as soft templates to direct polymer growth. The microstructures developed only in the presence of both ClO₄^– and H₂PO₄^– doping ions due to a slower rate of polymer propagation in this electrolyte. Two sonication methods (probe and bath) were used to form the emulsion, producing significantly different microstructure morphologies. Control over microtube diameter can be achieved by simply altering the emulsion sonication time or the amount of toluene added to form the emulsion. Electrochemical characterization indicated the PPyEtCN microtube morphology had an increased electrochemical response compared to its bulk counterpart. TEM analysis of individual closed-pore microtubes identified a hollow interior at the base within which the toluene droplet was encapsulated. This cavity may be used to entrap other compounds making these materials useful in a range of applications. The methodology was also applied to form microstructures of poly­(3,4-ethylenedioxythiophene) and polypyrrole

Position paper for the organization of ECMO programs for cardiac failure in adults

Extracorporeal membrane oxygenation (ECMO) has been used increasingly for both respiratory and cardiac failure in adult patients. Indications for ECMO use in cardiac failure include severe refractory cardiogenic shock, refractory ventricular arrhythmia, active cardiopulmonary resuscitation for cardiac arrest, and acute or decompensated right heart failure. Evidence is emerging to guide the use of this therapy for some of these indications, but there remains a need for additional evidence to guide best practices. As a result, the use of ECMO may vary widely across centers. The purpose of this document is to highlight key aspects of care delivery, with the goal of codifying the current use of this rapidly growing technology. A major challenge in this field is the need to emergently deploy ECMO for cardiac failure, often with limited time to assess the appropriateness of patients for the intervention. For this reason, we advocate for a multidisciplinary team of experts to guide institutional use of this therapy and the care of patients receiving it. Rigorous patient selection and careful attention to potential complications are key factors in optimizing patient outcomes. Seamless patient transport and clearly defined pathways for transition of care to centers capable of providing heart replacement therapies (e.g., durable ventricular assist device or heart transplantation) are essential to providing the highest level of care for those patients stabilized by ECMO but unable to be weaned from the device. Ultimately, concentration of the most complex care at high-volume centers with advanced cardiac capabilities may be a way to significantly improve the care of this patient population