- Email: [email protected]
Hydranautics launches low-fouling, high-flow RO element
NEWS
UK researchers develop new way of producing nanotubes
A
team of scientists working at the University of Warwick in the UK claims that it has found a way of producing carbon nanotubes in which they instantly form a highly sensitive, ready-made electric circuit. The researchers have been able to use this new method of single-walled nanotube (SWNT) assembly to produce carbon nanotubes that are useful as fuel cell catalysts. The research team – led by Professor Julie Macpherson, with Ioana Dumitrescu, Professor Patrick Unwin and Neil Wilson – used a form of chemical vapor deposition and lithography to create the ready-made, disk-shaped, SWNT-based ultra-microelectrodes. The nanotubes deposit themselves flat on a surface in a random but relatively even manner. They also all overlap sufficiently to create a single complete metallic microcircuit across the entire final disk, even though they take up less than 1% of the surface area of the disk. This latter property makes these electrodes particular useful for ultra-sensitive sensors. The low surface area of the conducting part of the disk means that they can be used to screen out background noise and cope with low signal-to-noise ratios, making them up to 1000 times more sensitive than conventional ultra-microelectrode sensors. This also produces very fast response times, say the researchers. The new ultra-microelectrodes also open up interesting possibilities as fuel cell catalysts. Previously it was known that this form of carbon nanotube appears to be particularly useful for catalysis, but it was not clear whether this was because of their intrinsic properties, or production impurities. The researchers have been able to use this new method of SWNT assembly to prove that it is the properties of the carbon nanotubes themselves that are useful for catalysis. The new carbon nanotube assembly technique brings a further benefit to catalysis applications, as the Warwick researchers have been able to use electro-deposition to quickly and easily apply specific metal coatings to the ready-formed SWNT microelectrode networks. This will be of significant benefit for the use of SWNTs for catalysis in fuel cell technology. The research has just been published in Analytical Chemistry [DOI: 10.1021/ac702518g]. 8
Membrane Technology
Contact: Professor Julie Macpherson, Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK. Tel: +44 2476 573886, Email: [email protected], www2.warwick.ac.uk/fac/sci/chemistry/cim/research/ electrochemistry
Hydranautics launches low-fouling, high-flow RO element
H
ydranautics, a US-based membrane company that is part of Nitto Denko Corporation, has introduced the composite polyamide CPA3-LD spiral-wound reverse osmosis (RO) element. According to the company, industries that require high purity water – particularly those in developing countries with limited access to municipally treated feed-water – will reap the benefits of this hard-to-foul, high-performance element. The low differential-pressure CPA3-LD element has a 31 mil brine spacer. This thicker spacer lowers the differential pressure, making it a perfect fit for scenarios that demand a low fouling and low maintenance membrane, while maintaining high permeate flow. The spacer also enhances the flux distribution in the RO system. Efficiency is improved because there is less flux loss in the pressure vessel from membrane to membrane. Hydranautics’ CPA3-LD operates at a flow rate of 41.6 m3 (11 000 gallons) of water per day at 99.7% nominal salt rejection. In the past, membrane area typically had to be sacrificed when using a thicker brine spacer, says Hydranautics. By using automated manufacturing systems, the company is able to maintain the CPA3-LD’s 400 ft2 (37.16 m2) area and performance, and still use the thicker 31 mil spacer. The CPA3-LD membrane elements are available in a 20 cm (8 inch) diameter/ 40 cm (40 inch) long configuration, and can be used as either a stand-alone product or part of the firm’s Integrated Membrane Solution (IMS). The CPA3-LD is part of a line of membranes that has a global installed capacity of more than 3.215 million m3 (850 million gallons) of clean water a day. Based in Oceanside, California, with sales offices throughout the world, Hydranautics was founded in 1963. During 1987 it became part of Nitto Denko, a multibillion dollar corporation based in Osaka, Japan. Hydranautics manufactures RO,
nanofiltration and ultrafiltration membrane products for water treatment applications. Contact: Hydranautics, 401 Jones Road, Oceanside, CA 92054, USA. Tel: +1 760 901 2500, www.membranes.com
Materials for fuel cells examined
R
esearch and Markets Ltd of Dublin, Ireland has added a report entitled Materials for Fuel Cells to its range of products. As the development of fuel cells continues, there is always a need for better materials to make these electrochemical devices cost-effective and more durable. This book reviews developments in materials that are able to fulfil the potential of fuel cells as a major source of power. After introductory chapters on the key issues in fuel-cell materials research, the book reviews the major types of devices. It considers the full range of technologies, including alkaline, polymer electrolyte, direct methanol, phosphoric acid, molten carbonate, solid oxide and regenerative fuel cells. The book concludes with reviews of novel fuel-cell materials, ways of analysing performance, and issues affecting life-cycle assessment and their ability to be recycled. Research and Markets says that Materials for Fuel Cells will be a valuable reference for all those researching, manufacturing and using fuel cells in areas such as automotive engineering. Key topics covered by the publication, with particular relevance to membranes, include: • membrane development for polymer electrolyte fuel cells; • sulfonated ionomer membranes and perfluorinated ionomer membranes; • partially fluorinated membranes; • non-fluorinated membranes; • (het)arylene main chain ionomer membranes; • cross-linked membrane systems and composite systems; • intermediate-temperature membrane systems; • catalyst development and catalyst supports; • gas diffusion media; and • membrane-electrode assemblies (MEAs).
Contact: Research and Markets Ltd, Guinness Centre, Taylors Lane, Dublin 8, Ireland. Fax: +353 1 481 1716, www.researchandmarkets.com
October 2008
UK researchers develop new way of producing nanotubes
A
team of scientists working at the University of Warwick in the UK claims that it has found a way of producing carbon nanotubes in which they instantly form a highly sensitive, ready-made electric circuit. The researchers have been able to use this new method of single-walled nanotube (SWNT) assembly to produce carbon nanotubes that are useful as fuel cell catalysts. The research team – led by Professor Julie Macpherson, with Ioana Dumitrescu, Professor Patrick Unwin and Neil Wilson – used a form of chemical vapor deposition and lithography to create the ready-made, disk-shaped, SWNT-based ultra-microelectrodes. The nanotubes deposit themselves flat on a surface in a random but relatively even manner. They also all overlap sufficiently to create a single complete metallic microcircuit across the entire final disk, even though they take up less than 1% of the surface area of the disk. This latter property makes these electrodes particular useful for ultra-sensitive sensors. The low surface area of the conducting part of the disk means that they can be used to screen out background noise and cope with low signal-to-noise ratios, making them up to 1000 times more sensitive than conventional ultra-microelectrode sensors. This also produces very fast response times, say the researchers. The new ultra-microelectrodes also open up interesting possibilities as fuel cell catalysts. Previously it was known that this form of carbon nanotube appears to be particularly useful for catalysis, but it was not clear whether this was because of their intrinsic properties, or production impurities. The researchers have been able to use this new method of SWNT assembly to prove that it is the properties of the carbon nanotubes themselves that are useful for catalysis. The new carbon nanotube assembly technique brings a further benefit to catalysis applications, as the Warwick researchers have been able to use electro-deposition to quickly and easily apply specific metal coatings to the ready-formed SWNT microelectrode networks. This will be of significant benefit for the use of SWNTs for catalysis in fuel cell technology. The research has just been published in Analytical Chemistry [DOI: 10.1021/ac702518g]. 8
Membrane Technology
Contact: Professor Julie Macpherson, Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK. Tel: +44 2476 573886, Email: [email protected], www2.warwick.ac.uk/fac/sci/chemistry/cim/research/ electrochemistry
Hydranautics launches low-fouling, high-flow RO element
H
ydranautics, a US-based membrane company that is part of Nitto Denko Corporation, has introduced the composite polyamide CPA3-LD spiral-wound reverse osmosis (RO) element. According to the company, industries that require high purity water – particularly those in developing countries with limited access to municipally treated feed-water – will reap the benefits of this hard-to-foul, high-performance element. The low differential-pressure CPA3-LD element has a 31 mil brine spacer. This thicker spacer lowers the differential pressure, making it a perfect fit for scenarios that demand a low fouling and low maintenance membrane, while maintaining high permeate flow. The spacer also enhances the flux distribution in the RO system. Efficiency is improved because there is less flux loss in the pressure vessel from membrane to membrane. Hydranautics’ CPA3-LD operates at a flow rate of 41.6 m3 (11 000 gallons) of water per day at 99.7% nominal salt rejection. In the past, membrane area typically had to be sacrificed when using a thicker brine spacer, says Hydranautics. By using automated manufacturing systems, the company is able to maintain the CPA3-LD’s 400 ft2 (37.16 m2) area and performance, and still use the thicker 31 mil spacer. The CPA3-LD membrane elements are available in a 20 cm (8 inch) diameter/ 40 cm (40 inch) long configuration, and can be used as either a stand-alone product or part of the firm’s Integrated Membrane Solution (IMS). The CPA3-LD is part of a line of membranes that has a global installed capacity of more than 3.215 million m3 (850 million gallons) of clean water a day. Based in Oceanside, California, with sales offices throughout the world, Hydranautics was founded in 1963. During 1987 it became part of Nitto Denko, a multibillion dollar corporation based in Osaka, Japan. Hydranautics manufactures RO,
nanofiltration and ultrafiltration membrane products for water treatment applications. Contact: Hydranautics, 401 Jones Road, Oceanside, CA 92054, USA. Tel: +1 760 901 2500, www.membranes.com
Materials for fuel cells examined
R
esearch and Markets Ltd of Dublin, Ireland has added a report entitled Materials for Fuel Cells to its range of products. As the development of fuel cells continues, there is always a need for better materials to make these electrochemical devices cost-effective and more durable. This book reviews developments in materials that are able to fulfil the potential of fuel cells as a major source of power. After introductory chapters on the key issues in fuel-cell materials research, the book reviews the major types of devices. It considers the full range of technologies, including alkaline, polymer electrolyte, direct methanol, phosphoric acid, molten carbonate, solid oxide and regenerative fuel cells. The book concludes with reviews of novel fuel-cell materials, ways of analysing performance, and issues affecting life-cycle assessment and their ability to be recycled. Research and Markets says that Materials for Fuel Cells will be a valuable reference for all those researching, manufacturing and using fuel cells in areas such as automotive engineering. Key topics covered by the publication, with particular relevance to membranes, include: • membrane development for polymer electrolyte fuel cells; • sulfonated ionomer membranes and perfluorinated ionomer membranes; • partially fluorinated membranes; • non-fluorinated membranes; • (het)arylene main chain ionomer membranes; • cross-linked membrane systems and composite systems; • intermediate-temperature membrane systems; • catalyst development and catalyst supports; • gas diffusion media; and • membrane-electrode assemblies (MEAs).
Contact: Research and Markets Ltd, Guinness Centre, Taylors Lane, Dublin 8, Ireland. Fax: +353 1 481 1716, www.researchandmarkets.com
October 2008