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LEDs used to sense chemicals
Molecular sieves clean waste streams P,esearch into methods of cap turing radioactive chemicals present in hazardous waste has led to the development of new microporous materials that couht selectively clean-up liquid process or waste streams. The materials called Sandia Octahedral Molecular Sieves (SOMS) were discovered at the Sandia National Laboratories, USA. According to researchers, they may be suitable for use in a variety of industries including microelectronics fabrication, where purification of, or extraction from, liquid process or waste streams is a significant or costly problem. They also could help capture for reuse a variety of valuable materials such as chromium, cobalt, and nickel from industrial eft]uents. SOMS are tiny sponges that sucks up divalent cations, i.e. atom groups with a +2 charge into its microscopic pores and snares them at negatively charged bonding sites that have been vacated by ions with weaker charges - a well known process called ion exchange. However, the SOMS are selective about which ions they capture. By varying the openings on their crystalline surfaces from 4 to 15 angstroms researchers can select
the sizes of ions or molecules that can enter into the pores. SOMS are comprised of sodium niobium oxide, with transition metals such as titanium or zirconium added to give them their microporosity and ion exchange properties. Sandia already is studying ways to use SOMS to extract and reuse valuable cobalt from copper mine electrorefinement waste streams. Sandia worked in collaboration with researchers at the University of Calitk~rnia Davis (UC Davis), Pacific Northwest National Laboratory (PNNL), the University of Michigan, the
According toThomas Kuech, professor of chemical engineering and materials science, there is a large movement towards making sensors smaller and more versatile through the use the economy of scale found in the semicon ductor industry.The aim of the work is to develop very small optical emitters and detectors that are chemically sensitive to a wide range of substances present in the environment. The current research is based on the work of Arthur Ellis, professor of chemistry, which showed how light from LEDs can he altered by chemical exposure. Ellis together ~ith Keuch and electrical and computer State University of New York engineer Luke Mawst applied Stony Brook (SUNY), and this discovery to a new class of Lawrence Livermore National sensors. The group began by Laboratory (LLNL). changing the surface of the light emitting structure to LEDs u s e d t o s e n s e enhance its chemical senchemicals = sitivity, and then integrated it In a paper recently featured in onto a chip, xvith a nearby Nature, scientists at the Hnidetector system. This produced versity of Wisconsin-Madison, a simple chemical sensor that LISA, are developing highly can be built with the cost sensitive systems that use lighteftectiveness of computer chips emitting diodes (LEDs) to de and used to detect a wide tect chemicals in air or water. range of chemicals. Now, the Researchers have shown researchers are focusing on how light from LEDs change in achieving a better understand intensity in the presence of ing of the basic chemical reacchemicals, and how this change tions that are taking place on can he translated into a the surfaces of LEDs to ensure detection device. optimisation of the process.
Patent Summaries Centrifugal Filtration Apparatus, Schmidt G, Canada. WO 00/50150, Date of Publication: 31 August 2000 Process for Removing Hydrocarbons from a Liquid M i x t u r e w i t h a Regernable Filter, MPR Services Inc, USA. WO 00/53284. Date of Publication: 14 September 2000. M u l t i l y e r M e m b r a n e s and M e t h o d for the Production thereof, Institut for Polymerforschung
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April 2001
Dresden EV, Germany. WO 00/53296. Date of Publication: 14 September 2000. Polymer Filtration Apparatus, Dynisco Extrusion Inc, USA. WO 00/54958. Date of Publication: 21 September 2000. M e t h o d for Treating Water and Sewage Purification using a Fluidised Filter Bed, Harbs V, Germany. WO 00/56667. Date of Publication: 21 September 2000.
Filtration+Separation
the sizes of ions or molecules that can enter into the pores. SOMS are comprised of sodium niobium oxide, with transition metals such as titanium or zirconium added to give them their microporosity and ion exchange properties. Sandia already is studying ways to use SOMS to extract and reuse valuable cobalt from copper mine electrorefinement waste streams. Sandia worked in collaboration with researchers at the University of Calitk~rnia Davis (UC Davis), Pacific Northwest National Laboratory (PNNL), the University of Michigan, the
According toThomas Kuech, professor of chemical engineering and materials science, there is a large movement towards making sensors smaller and more versatile through the use the economy of scale found in the semicon ductor industry.The aim of the work is to develop very small optical emitters and detectors that are chemically sensitive to a wide range of substances present in the environment. The current research is based on the work of Arthur Ellis, professor of chemistry, which showed how light from LEDs can he altered by chemical exposure. Ellis together ~ith Keuch and electrical and computer State University of New York engineer Luke Mawst applied Stony Brook (SUNY), and this discovery to a new class of Lawrence Livermore National sensors. The group began by Laboratory (LLNL). changing the surface of the light emitting structure to LEDs u s e d t o s e n s e enhance its chemical senchemicals = sitivity, and then integrated it In a paper recently featured in onto a chip, xvith a nearby Nature, scientists at the Hnidetector system. This produced versity of Wisconsin-Madison, a simple chemical sensor that LISA, are developing highly can be built with the cost sensitive systems that use lighteftectiveness of computer chips emitting diodes (LEDs) to de and used to detect a wide tect chemicals in air or water. range of chemicals. Now, the Researchers have shown researchers are focusing on how light from LEDs change in achieving a better understand intensity in the presence of ing of the basic chemical reacchemicals, and how this change tions that are taking place on can he translated into a the surfaces of LEDs to ensure detection device. optimisation of the process.
Patent Summaries Centrifugal Filtration Apparatus, Schmidt G, Canada. WO 00/50150, Date of Publication: 31 August 2000 Process for Removing Hydrocarbons from a Liquid M i x t u r e w i t h a Regernable Filter, MPR Services Inc, USA. WO 00/53284. Date of Publication: 14 September 2000. M u l t i l y e r M e m b r a n e s and M e t h o d for the Production thereof, Institut for Polymerforschung
22
April 2001
Dresden EV, Germany. WO 00/53296. Date of Publication: 14 September 2000. Polymer Filtration Apparatus, Dynisco Extrusion Inc, USA. WO 00/54958. Date of Publication: 21 September 2000. M e t h o d for Treating Water and Sewage Purification using a Fluidised Filter Bed, Harbs V, Germany. WO 00/56667. Date of Publication: 21 September 2000.
Filtration+Separation