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Slightly smaller than our own moon, Europa could hardly appear more different. Both have interiors of rock and metal. But Europa is wrapped in a global saltwater ocean and covered by a bright shell of ice. The shell is scarred with cracks and faults and mottled places where the ice has been breached by liquid from below. Scientists have speculated for decades what lies within that ocean. It is larger in volume than all the oceans of Earth put together. A NASA-funded seismometer under development at Arizona State University holds the promise of landing on Europa's ice shell—and listening to it. The seismometer would use Europa's natural tides and other movements to discover the shell's thickness, see whether it holds pockets of water—subsurface lakes—within the ice, and determine how easily, and how often, ocean water could rise and spill out on the surface. "We want to hear what Europa has to tell us," said Hongyu Yu, of ASU's School of Earth and Space Exploration. "And that means putting a sensitive 'ear' on Europa's surface." Exploration systems engineer Yu heads up a team of ASU scientists that includes seismologist Edward Garnero, geophysicist Alyssa Rhoden, and chemical engineer Lenore Dai, director of the School for Engineering of Matter, Transport and Energy in the Ira A. Fulton Schools of Engineering. While there are no current plans to send a lander to Europa, the team has received a grant from NASA to develop and test a miniature seismometer no larger than about 4 inches (10 centimeters) on a side, which could be crucial in advancing future Europa exploration. Fittingly, considering where it is being created, the project is titled Seismometers for Exploring the Subsurface of Europa, or SESE. Most seismometers, whether for use on Earth or other planets, rely on a mass-and-spring sensor concept to detect passing earthquake waves. But that type of seismometer, says Yu, has to be set down in an upright position, it must be put in place carefully with no major jolts or shaking, and the chamber where the sensor operates needs a complete vacuum to ensure accurate measurements. "Our design avoids all these problems," Yu explains. The SESE seismometer uses a micro-electromechanical system with a liquid electrolyte as the sensor. "This design has a high sensitivity to a wide range of vibrations, and it can operate at any angle to the surface. "And if necessary," he adds, "they can hit the ground hard on landing." Yu notes that the team tested the prototype by hitting it with a sledgehammer. It survived. Besides being extremely rugged, the SESE seismometer promises to push ahead the state of the art in sensors as well. "We're excited at the opportunity to develop electrolytes and polymers beyond their traditional temperature limits," says team member Dai. "This project also exemplifies collaboration across disciplines." The ability to withstand a hard landing is a great help, says team member Garnero. "Seismometers need to connect with the solid ground to operate most effectively." Sitting on loose surface materials can isolate the instrument from seismic waves passing through the body of the moon or planet—or, on Europa, its ice shell. Landers, which would carry seismometers, "typically have four or six legs," Garnero said. "If each leg carries a seismometer, these could be pushed into the surface on landing, making good contact with the ground." In addition, he said, having a number of sensors on a lander gives scientists the opportunity to combine the data recorded at each. This lets them overcome the variable seismic vibrations recorded by each instrument, and it allows scientists to tell what direction quake waves come from. "We can also sort out high frequency signals from longer wavelength ones," Garnero explained. The wider the spectrum the instrument can sense, the more phenomena it will detect. "For example, small meteorites hitting the surface not too far away would produce high frequency waves, and tides of gravitational tugs from Jupiter and Europa's neighbor moons would make long, slow waves." So what would Europa sound like? Garnero laughed. "I think we'll hear things that we won't know what they are." But, he said, "ice being deformed on a local scale would be high in frequency—we'd hear sharp pops and cracks. From ice shell movements on a more planetary scale, I would expect creaks and groans." Europa can be glimpsed in binoculars from the backyard as it circles Jupiter once every 85 hours. But it's just a point of light, looking no different from what Galileo saw when he discovered it. The Europa that scientists study today, however, is more properly considered an ocean world. This is because of two flyby spacecraft (NASA's Voyager 1 and 2) and an orbiter (NASA's Galileo) that spent eight years at Jupiter. Long-distance observations of Europa also have come from the Hubble Space Telescope orbiting Earth, which detected plumes of water vapor erupting from the shell in 2012 and 2016. "At Europa, we're trying to use seismometers to determine where the liquid water lies within the ice shell," team member Rhoden said. "We want to know how active the ice shell is." The answers to these questions are important to the future exploration of this moon and its habitability, she said. "An active shell with pockets of water creates more niches for life and more ways to transport nutrients from the ocean to the surface." Locating these pockets on Europa would allow future lander missions to possibly sample ocean water brought up through the ice shell. Just how active is Europa? "We don't know," Rhoden said. The surface is geologically young, with an approximate age (based on numbers of craters) of 50 to 100 million years. "It may have undergone an epoch of activity early in that period and then shut down." But it's equally possible, she says, that the shell is experiencing fractures, uplifts, offsets, and melt-throughs today. "Hubble's recent plume observations last fall appear to support that." As Europa orbits Jupiter, it gets repeated tugs from the gravity of neighbor moons Io and Ganymede. These tugs keep Europa's orbit from becoming circular and that lets Jupiter stress the shell—and then let it relax—over and over, endlessly. Thus, Rhoden said, seismometers on the surface should detect any ongoing activity in the shell. The team developing the SESE seismometer has its sights on Europa, but they are also looking beyond, because the design is robust and adaptable. This could let it become something of a universal instrument for seismology on other worlds. As team leader Yu explains, "With modification to fit local environments, this instrument should work on Venus and Mars, and likely other planets and moons, too."


News Article | May 10, 2017
Site: www.eurekalert.org

Jupiter's moon Europa is definitely an odd place. Discovered in 1610 by Galileo Galilei, it was first seen in detail only in the late 1970s, after spacecraft visited the jovian system. Slightly smaller than our own moon, Europa could hardly appear more different. Both have interiors of rock and metal. But Europa is wrapped in a global saltwater ocean and covered by a bright shell of ice. The shell is scarred with cracks and faults and mottled places where the ice has been breached by liquid from below. Scientists have speculated for decades what lies within that ocean. It is larger in volume than all the oceans of Earth put together. A NASA-funded seismometer under development at Arizona State University holds the promise of landing on Europa's ice shell -- and listening to it. The seismometer would use Europa's natural tides and other movements to discover the shell's thickness, see whether it holds pockets of water -- subsurface lakes -- within the ice, and determine how easily, and how often, ocean water could rise and spill out on the surface. "We want to hear what Europa has to tell us," said Hongyu Yu, of ASU's School of Earth and Space Exploration. "And that means putting a sensitive 'ear' on Europa's surface." Exploration systems engineer Yu heads up a team of ASU scientists that includes seismologist Edward Garnero, geophysicist Alyssa Rhoden, and chemical engineer Lenore Dai, director of the School for Engineering of Matter, Transport and Energy in the Ira A. Fulton Schools of Engineering. While there are no current plans to send a lander to Europa, the team has received a grant from NASA to develop and test a miniature seismometer no larger than about 4 inches (10 centimeters) on a side, which could be crucial in advancing future Europa exploration. Fittingly, considering where it is being created, the project is titled Seismometers for Exploring the Subsurface of Europa, or SESE. Most seismometers, whether for use on Earth or other planets, rely on a mass-and-spring sensor concept to detect passing earthquake waves. But that type of seismometer, says Yu, has to be set down in an upright position, it must be put in place carefully with no major jolts or shaking, and the chamber where the sensor operates needs a complete vacuum to ensure accurate measurements. "Our design avoids all these problems," Yu explains. The SESE seismometer uses a micro-electromechanical system with a liquid electrolyte as the sensor. "This design has a high sensitivity to a wide range of vibrations, and it can operate at any angle to the surface. "And if necessary," he adds, "they can hit the ground hard on landing." Yu notes that the team tested the prototype by hitting it with a sledgehammer. It survived. Besides being extremely rugged, the SESE seismometer promises to push ahead the state of the art in sensors as well. "We're excited at the opportunity to develop electrolytes and polymers beyond their traditional temperature limits," says team member Dai. "This project also exemplifies collaboration across disciplines." The ability to withstand a hard landing is a great help, says team member Garnero. "Seismometers need to connect with the solid ground to operate most effectively." Sitting on loose surface materials can isolate the instrument from seismic waves passing through the body of the moon or planet -- or, on Europa, its ice shell. Landers, which would carry seismometers, "typically have four or six legs," Garnero said. "If each leg carries a seismometer, these could be pushed into the surface on landing, making good contact with the ground." In addition, he said, having a number of sensors on a lander gives scientists the opportunity to combine the data recorded at each. This lets them overcome the variable seismic vibrations recorded by each instrument, and it allows scientists to tell what direction quake waves come from. "We can also sort out high frequency signals from longer wavelength ones," Garnero explained. The wider the spectrum the instrument can sense, the more phenomena it will detect. "For example, small meteorites hitting the surface not too far away would produce high frequency waves, and tides of gravitational tugs from Jupiter and Europa's neighbor moons would make long, slow waves." So what would Europa sound like? Garnero laughed. "I think we'll hear things that we won't know what they are." But, he said, "ice being deformed on a local scale would be high in frequency -- we'd hear sharp pops and cracks. From ice shell movements on a more planetary scale, I would expect creaks and groans." Europa can be glimpsed in binoculars from the backyard as it circles Jupiter once every 85 hours. But it's just a point of light, looking no different from what Galileo saw when he discovered it. The Europa that scientists study today, however, is more properly considered an ocean world. This is because of two flyby spacecraft (NASA's Voyager 1 and 2) and an orbiter (NASA's Galileo) that spent eight years at Jupiter. Long-distance observations of Europa also have come from the Hubble Space Telescope orbiting Earth, which detected plumes of water vapor erupting from the shell in 2012 and 2016. "At Europa, we're trying to use seismometers to determine where the liquid water lies within the ice shell," team member Rhoden said. "We want to know how active the ice shell is." The answers to these questions are important to the future exploration of this moon and its habitability, she said. "An active shell with pockets of water creates more niches for life and more ways to transport nutrients from the ocean to the surface." Locating these pockets on Europa would allow future lander missions to possibly sample ocean water brought up through the ice shell. Just how active is Europa? "We don't know," Rhoden said. The surface is geologically young, with an approximate age (based on numbers of craters) of 50 to 100 million years. "It may have undergone an epoch of activity early in that period and then shut down." But it's equally possible, she says, that the shell is experiencing fractures, uplifts, offsets, and melt-throughs today. "Hubble's recent plume observations last fall appear to support that." As Europa orbits Jupiter, it gets repeated tugs from the gravity of neighbor moons Io and Ganymede. These tugs keep Europa's orbit from becoming circular and that lets Jupiter stress the shell -- and then let it relax -- over and over, endlessly. Thus, Rhoden said, seismometers on the surface should detect any ongoing activity in the shell. The team developing the SESE seismometer has its sights on Europa, but they are also looking beyond, because the design is robust and adaptable. This could let it become something of a universal instrument for seismology on other worlds. As team leader Yu explains, "With modification to fit local environments, this instrument should work on Venus and Mars, and likely other planets and moons, too."


News Article | May 10, 2017
Site: astrobiology.com

Jupiter's moon Europa is definitely an odd place. Discovered in 1610 by Galileo Galilei, it was first seen in detail only in the late 1970s, after spacecraft visited the Jovian system. Slightly smaller than our own moon, Europa could hardly appear more different. Both have interiors of rock and metal. But Europa is wrapped in a global saltwater ocean and covered by a bright shell of ice. The shell is scarred with cracks and faults and mottled places where the ice has been breached by liquid from below. Scientists have speculated for decades what lies within that ocean. It is larger in volume than all the oceans of Earth put together. A NASA-funded seismometer under development at Arizona State University holds the promise of landing on Europa's ice shell -- and listening to it. The seismometer would use Europa's natural tides and other movements to discover the shell's thickness, see whether it holds pockets of water -- subsurface lakes -- within the ice, and determine how easily, and how often, ocean water could rise and spill out on the surface. "We want to hear what Europa has to tell us," said Hongyu Yu, of ASU's School of Earth and Space Exploration (SESE). "And that means putting a sensitive 'ear' on Europa's surface." Exploration systems engineer Yu heads up a team of ASU scientists that includes seismologist Edward Garnero, geophysicist Alyssa Rhoden, and chemical engineer Lenore Dai, director of the School for Engineering of Matter, Transport and Energy in the Ira A. Fulton Schools of Engineering. While there are no current plans to send a lander to Europa, the team has received a grant from NASA to develop and test a miniature seismometer no larger than about 4 inches (10 centimeters) on a side, which could be crucial in advancing future Europa exploration. Fittingly, considering where it is being created, the project is titled Seismometers for Exploring the Subsurface of Europa, or SESE. Most seismometers, whether for use on Earth or other planets, rely on a mass-and-spring sensor concept to detect passing earthquake waves. But that type of seismometer, says Yu, has to be set down in an upright position, it must be put in place carefully with no major jolts or shaking, and the chamber where the sensor operates needs a complete vacuum to ensure accurate measurements. "Our design avoids all these problems," Yu explains. The SESE seismometer uses a micro-electromechanical system with a liquid electrolyte as the sensor. "This design has a high sensitivity to a wide range of vibrations, and it can operate at any angle to the surface. "And if necessary," he adds, "they can hit the ground hard on landing." Yu notes that the team tested the prototype by hitting it with a sledgehammer. It survived. Besides being extremely rugged, the SESE seismometer promises to push ahead the state of the art in sensors as well. "We're excited at the opportunity to develop electrolytes and polymers beyond their traditional temperature limits," says team member Dai. "This project also exemplifies collaboration across disciplines." The ability to withstand a hard landing is a great help, says team member Garnero. "Seismometers need to connect with the solid ground to operate most effectively." Sitting on loose surface materials can isolate the instrument from seismic waves passing through the body of the moon or planet -- or, on Europa, its ice shell. Landers, which would carry seismometers, "typically have four or six legs," Garnero said. "If each leg carries a seismometer, these could be pushed into the surface on landing, making good contact with the ground." In addition, he said, having a number of sensors on a lander gives scientists the opportunity to combine the data recorded at each. This lets them overcome the variable seismic vibrations recorded by each instrument, and it allows scientists to tell what direction quake waves come from. "We can also sort out high frequency signals from longer wavelength ones," Garnero explained. The wider the spectrum the instrument can sense, the more phenomena it will detect. "For example, small meteorites hitting the surface not too far away would produce high frequency waves, and tides of gravitational tugs from Jupiter and Europa's neighbor moons would make long, slow waves." So what would Europa sound like? Garnero laughed. "I think we'll hear things that we won't know what they are." But, he said, "ice being deformed on a local scale would be high in frequency -- we'd hear sharp pops and cracks. From ice shell movements on a more planetary scale, I would expect creaks and groans." Europa can be glimpsed in binoculars from the backyard as it circles Jupiter once every 85 hours. But it's just a point of light, looking no different from what Galileo saw when he discovered it. The Europa that scientists study today, however, is more properly considered an ocean world. This is because of two flyby spacecraft (NASA's Voyager 1 and 2) and an orbiter (NASA's Galileo) that spent eight years at Jupiter. Long-distance observations of Europa also have come from the Hubble Space Telescope orbiting Earth, which detected plumes of water vapor erupting from the shell in 2012 and 2016. "At Europa, we're trying to use seismometers to determine where the liquid water lies within the ice shell," team member Rhoden said. "We want to know how active the ice shell is." The answers to these questions are important to the future exploration of this moon and its habitability, she said. "An active shell with pockets of water creates more niches for life and more ways to transport nutrients from the ocean to the surface." Locating these pockets on Europa would allow future lander missions to possibly sample ocean water brought up through the ice shell. Just how active is Europa? "We don't know," Rhoden said. The surface is geologically young, with an approximate age (based on numbers of craters) of 50 to 100 million years. "It may have undergone an epoch of activity early in that period and then shut down." But it's equally possible, she says, that the shell is experiencing fractures, uplifts, offsets, and melt-throughs today. "Hubble's recent plume observations last fall appear to support that." As Europa orbits Jupiter, it gets repeated tugs from the gravity of neighbor moons Io and Ganymede. These tugs keep Europa's orbit from becoming circular and that lets Jupiter stress the shell -- and then let it relax -- over and over, endlessly. Thus, Rhoden said, seismometers on the surface should detect any ongoing activity in the shell. The team developing the SESE seismometer has its sights on Europa, but they are also looking beyond, because the design is robust and adaptable. This could let it become something of a universal instrument for seismology on other worlds. As team leader Yu explains, "With modification to fit local environments, this instrument should work on Venus and Mars, and likely other planets and moons, too."


News Article | May 10, 2017
Site: www.chromatographytechniques.com

Jupiter's moon Europa is definitely an odd place. Discovered in 1610 by Galileo Galilei, it was first seen in detail only in the late 1970s, after spacecraft visited the jovian system. Slightly smaller than our own moon, Europa could hardly appear more different. Both have interiors of rock and metal. But Europa is wrapped in a global saltwater ocean and covered by a bright shell of ice. The shell is scarred with cracks and faults and mottled places where the ice has been breached by liquid from below. Scientists have speculated for decades what lies within that ocean. It is larger in volume than all the oceans of Earth put together. A NASA-funded seismometer under development at Arizona State University holds the promise of landing on Europa's ice shell — and listening to it. The seismometer would use Europa's natural tides and other movements to discover the shell's thickness, see whether it holds pockets of water — subsurface lakes — within the ice, and determine how easily, and how often, ocean water could rise and spill out on the surface. "We want to hear what Europa has to tell us," said Hongyu Yu, of ASU's School of Earth and Space Exploration. "And that means putting a sensitive 'ear' on Europa's surface." Exploration systems engineer Yu heads up a team of ASU scientists that includes seismologist Edward Garnero, geophysicist Alyssa Rhoden, and chemical engineer Lenore Dai, director of the School for Engineering of Matter, Transport and Energy in the Ira A. Fulton Schools of Engineering. While there are no current plans to send a lander to Europa, the team has received a grant from NASA to develop and test a miniature seismometer no larger than about 4 inches (10 centimeters) on a side, which could be crucial in advancing future Europa exploration. Fittingly, considering where it is being created, the project is titled Seismometers for Exploring the Subsurface of Europa, or SESE. Most seismometers, whether for use on Earth or other planets, rely on a mass-and-spring sensor concept to detect passing earthquake waves. But that type of seismometer, says Yu, has to be set down in an upright position, it must be put in place carefully with no major jolts or shaking, and the chamber where the sensor operates needs a complete vacuum to ensure accurate measurements. "Our design avoids all these problems," Yu explains. The SESE seismometer uses a micro-electromechanical system with a liquid electrolyte as the sensor. "This design has a high sensitivity to a wide range of vibrations, and it can operate at any angle to the surface. "And if necessary," he adds, "they can hit the ground hard on landing." Yu notes that the team tested the prototype by hitting it with a sledgehammer. It survived. Besides being extremely rugged, the SESE seismometer promises to push ahead the state of the art in sensors as well. "We're excited at the opportunity to develop electrolytes and polymers beyond their traditional temperature limits," says team member Dai. "This project also exemplifies collaboration across disciplines."


Neerukatti R.K.,School for Engineering of Matter | Rajadas A.,School for Engineering of Matter | Borkowski L.,School for Engineering of Matter | Chattopadhyay A.,School for Engineering of Matter | Huff D.W.,Boeing Company
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2016

Advanced composite structures, such as foam core carbon fiber reinforced polymer composites, are increasingly being used in applications which require high strength, high in-plane and flexural stiffness, and low weight. However, the presence of in situ damage due to manufacturing defects and/or service conditions can complicate the failure mechanisms and compromise their strength and reliability. In this paper, the capability of detecting damages such as delaminations and foam-core separations in X-COR composite structures using non-destructive evaluation (NDE) and structural health monitoring (SHM) techniques is investigated. Two NDE techniques, flash thermography and low frequency ultrasonics, were used to detect and quantify the damage size and locations. Macro fiber composites (MFCs) were used as actuators and sensors to study the interaction of Lamb waves with delaminations and foam-core separations. The results indicate that both flash thermography and low frequency ultrasonics were capable of detecting damage in X-COR sandwich structures, although low frequency ultrasonic methods were capable of detecting through thickness damages more accurately than flash thermography. It was also observed that the presence of foam-core separations significantly changes the wave behavior when compared to delamination, which complicates the use of wave based SHM techniques. Further, a wave propagation model was developed to model the wave interaction with damages at different locations on the X-COR sandwich plate. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.


Stith J.L.,U.S. National Center for Atmospheric Research | Twohy C.H.,Oregon State University | Demott P.J.,Colorado State University | Baumgardner D.,National Autonomous University of Mexico | And 3 more authors.
Atmospheric Chemistry and Physics | Year: 2011

In situ airborne sampling of refractory black carbon (rBC) particles and Ice Nuclei (IN) was conducted in and near an extratropical cyclonic storm in the western Pacific Ocean during the Pacific Dust Experiment, PACDEX, in the spring of 2007. Airmass origins were from Eastern Asia. Clouds associated primarily with the warm sector of the storm were sampled at various locations and altitudes. Cloud hydrometeors were evaporated by a counterflow virtual impactor (CVI) and the residuals were sampled by a single particle soot photometer (SP2) instrument, a continuous flow diffusion chamber ice nucleus detector (CFDC) and collected for electron microscope analysis. In clouds containing large ice particles, multiple residual particles were observed downstream of the CVI for each ice particle sampled on average. The fraction of rBC compared to total particles in the residual particles increased with decreasing condensed water content, while the fraction of IN compared to total particles did not, suggesting that the scavenging process for rBC is different than for IN. In the warm sector storm midlevels at temperatures where heterogeneous freezing is expected to be significant (here ĝ̂'24 to ĝ̂'29 °C), IN concentrations from ice particle residuals generally agreed with simultaneous measurements of total ice concentrations or were higher in regions where aggregates of crystals were found, suggesting heterogeneous freezing as the dominant ice formation process in the mid levels of these warm sector clouds. Lower in the storm, at warmer temperatures, ice concentrations were affected by aggregation and were somewhat less than measured IN concentrations at colder temperatures. The results are consistent with ice particles forming at storm mid-levels by heterogeneous freezing on IN, followed by aggregation and sedimentation to lower altitudes. Compositional analysis of the aerosol and back trajectories of the air in the warm sector suggested a possible biomass burning source for much of the aerosol. Comparison of the particles from the CFDC with the other aerosol in the residuals of ice particles suggested that the largest portion of IN had similar inferred origins (from biomass burning with minor amounts of rBC) as the other aerosol, but contained slightly elevated amounts of calcium and less influence from sea salt. © 2011 Author(s).


Deshpande S.,Arizona State University | Rivera D.E.,School for Engineering of Matter
Proceedings of the IEEE Conference on Decision and Control | Year: 2014

Data-centric system identification approaches generate a local function approximation from a database of regressors at a given operating point. This paper studies the design of input signals for data-centric identification of highly interactive multivariable systems which show strong gain directionality. The input signal design formulation aims to develop uniform coverage in the output space by addressing the optimal distribution of time-indexed output points under general operating constraints on the manipulated input and measured output signals. The solution of resulting nonconvex quadratic program is proposed using semidefinite and nonlinear programming methods. A numerical example is shown to highlight the benefit of proposed design in comparison to the input design based on Weyl's criterion for data of finite length. © 2014 IEEE.


Cheng Q.,School for Engineering of Matter | Song Z.,School for Engineering of Matter | Ma T.,School for Engineering of Matter | Smith B.B.,School for Engineering of Matter | And 4 more authors.
Nano Letters | Year: 2013

Paper folding techniques are used in order to compact a Li-ion battery and increase its energy per footprint area. Full cells were prepared using Li 4Ti5O12 and LiCoO2 powders deposited onto current collectors consisting of paper coated with carbon nanotubes. Folded cells showed higher areal capacities compared to the planar versions with a 5 × 5 cell folded using the Miura-ori pattern displaying a ∼14× increase in areal energy density. © 2013 American Chemical Society.


Deshpande S.,Arizona State University | Rivera D.E.,School for Engineering of Matter
Proceedings of the IEEE Conference on Decision and Control | Year: 2013

This paper examines the design of input signals for identification of Hammerstein systems in a data-centric framework by addressing the optimal distribution of regressors. Data-centric estimation methods such as Model-on-Demand (MoD) generate local function approximations from a database of regressors at the current operating point. The data-centric input signal design formulation aims to develop sufficient support in the regressor space for the MoD estimator, while addressing time-domain constraints on the input and output signals. A numerical example is shown to highlight the benefit of proposed design over classical Pseudo Random Binary Sequence (PRBS), Multi Level Pseudo Random Sequence (MLPRS) and uniform random input designs. © 2013 IEEE.


Yadav A.,School for Engineering of Matter | Lind M.L.,School for Engineering of Matter | Ma X.,School for Engineering of Matter | Lin Y.S.,School for Engineering of Matter
Industrial and Engineering Chemistry Research | Year: 2013

Separation of alcohols from dilute aqueous solutions is important to enable continuous microbial production of biofuels. Pervaporation is a process with great potential for continuous extraction of alcohols from biological fermentation broths. Here, we report on the synthesis and pervaporation performance of thin, supported pure polydimethylsiloxane (PDMS) and silicalite-1/PDMS nanocomposite membranes with nanoparticle contents of 10, 20, and 30 wt %. Using a batch pervaporation system, we measured flux and separation factors of the membranes for solutions of 4 wt % ethanol in water at 25 °C, 50 °C, and 65 °C. With increased nanosilicalite loadings in the nanocomposite membranes, we obtained both increased flux and increased alcohol separation factors. © 2013 American Chemical Society.

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