Designing a Graphene Filter to make Seawater Drinkable and … Cheaper


Seawater drinking water imagesAs drinking water grows scarce, desalination might be one way to bridge the gap.

 

A new study released earlier this week in the journal Nature Nanotechnology may be a major step towards making desalinated water—water in which salt is removed to make it safe for drinking—a viable option for more of the world. Researchers from the University of Manchester modified graphene oxide membranes, a type of selectively permeable membrane that allows some molecules to pass while keeping others behind, to let water through while trapping salt ions. It’s essentially a molecular sieve.

Finding new sources of fresh water is important, because roughly 20 percent of the world’s population—1.2 billion people—lack access to clean drinking water, according to the United Nations. It’s a number that’s expected to grow as populations increase and existing water supplies dwindle, in part due to climate change. This reality has led some to suggest that the world’s next “gold rush” will be for water. Others have a less sanguine approach, worrying that the wars of the future will be fought over water. And this concern is not without merit: the war currently raging in Yemen is linked, at least in part, to water conflicts. All the Water we have Energy-recovery-desalination-1

 

But while fresh water is scarce (a scant three percent of the world’s water is fresh) water itself is not. The Earth is more than 70 percent water, but 97 percent is undrinkable because it’s either salt or brackish (a mix of salt and fresh water). The occasional gulp of seawater while swimming aside, drinking saltwater is dangerous for humans—it leads to dehydration and eventually death. Hence the famous lined from the Rhyme of the Ancient Mariner: “water, water everywhere, nor any drop to drink.”

Desalination could be a solution. After all, the technique is already employed in parts of the Middle East and the Cayman Islands. However, the two techniques currently employed—multi-stage flash distillation, which flash heats a portion of the water into steam through a series of heat exchanges, and reverse osmosis, which uses a high-pressure pump to push sea water through reverse osmosis membranes to remove ions and particles from drinking water—have several key drawbacks.

“Current desalination methods are energy intensive and produce adverse environmental impact,” wrote Ram Devanathan a researcher at the Energy and Environment Directorate at Pacific Northwest National Laboratory, in an op-ed that accompanied the study. “Furthermore, energy production consumes large quantities of water and creates wastewater that needs to be treated with further energy input.”

Graphene oxide membranes show promise as a relatively inexpensive alternative, because they can be cheaply produced in a lab—and though water easily passes through them, salts do not. However, when immersed in water on a large-scale, graphene oxide membranes tend to quickly swell. Once swollen, the membranes not only allow water to pass through, but also sodium and magnesium ions, i.e. salt, defeating the purpose of the filtration.

Study author Rahul Nair and his colleagues discovered that by placing walls made of epoxy resin on either side of the graphene oxide, they could stop the expansion. And by restricting the membranes with resin, they were able to fine tune their capillary size to prevent any errant salts from hitching a ride on water molecules.

The next step will be testing it on an industrial scale to see if the method holds up. If it works, many people might just be drinking (a glass of water) to it.

Genesis Nanotech Headlines Are Out!


Organ on a chip organx250Genesis Nanotech Headlines Are Out! Read All About It!

https://paper.li/GenesisNanoTech/1354215819#!headlines

Visit Our Website: www.genesisnanotech.com

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SUBCOMMITTE EXAMINES BREAKTHROUGH NANOTECHNOLOGY OPPORTUNITIES FOR AMERICA

Chairman Terry: “Nanotech is a true science race between the nations, and we should be encouraging the transition from research breakthroughs to commercial development.”

WASHINGTON, DCThe Subcommittee on Commerce, Manufacturing, and Trade, chaired by Rep. Lee Terry (R-NE), today held a hearing on:

“Nanotechnology: Understanding How Small Solutions Drive Big Innovation.”

 

 

electron-tomography

“Great Things from Small Things!” … We Couldn’t Agree More!

 

Gold Nano-Clusters: Tiny Building Blocks for Chemical Sensors, Energy Conversion & Storage


gold_sidBy colliding ultra-small gold particles with a surface and analyzing the resulting fragments, a trio of scientists at Pacific Northwest National Laboratory discovered how and why the particles break. This information is important for controlling the synthesis of these tiny building blocks that are of interest to catalysis, energy conversion and storage, and chemical sensing.

 

 

The team showed that the particles break along three competing pathways. The path chosen by a specific cluster depends on the amount of energy that binds it together as well as whether a given pathway leads to rapid or slow fragmentation. Particles with eight gold atoms wrapped with six ligands or phosphorus-based strands proved exceptionally stable in part because the ligands tightly bind to the gold core.

What determines the stability of gold clusters, which may be the building blocks of new energy technologies? By colliding the ultra-small particles with a surface and analyzing the resulting fragments, scientists found that the binding energy between the gold center and the surrounding molecular framework is key. This work was done by a team at PNNL, using resources at DOE’s EMSL, a national scientific user facility. >>>

gold_sid

“There is substantial interest in many disciplines that wish to control the synthesis of metal clusters,” said Dr. Julia Laskin, a physical chemist and Laboratory Fellow who led the study. “These particles’ optical and electronic properties make them promising candidates for applications in catalysis, photovoltaics, and drug delivery.”

Why It Matters:

Today’s materials will not likely solve our nation’s mounting energy challenges. They simply don’t have the necessary properties to produce more efficient catalysts or solar cells that create, store, and use energy on a massive scale. Employing ultra-small particles, scientists are synthesizing highly tailored materials with the desired stability and chemical reactivity. However, in many cases, researchers lack basic thermodynamic and kinetic information about how the particles behave. The study done at PNNL — which is the first of its kind — provides fundamental knowledge that allows researchers to control the synthesis of gold particles or other nanosized clusters in a more rational manner.

“By understanding the fundamentals of cluster synthesis through thermochemistry, we may control and exploit these processes to create superior materials for a variety of energy-related applications,” said Dr. Grant Johnson, a PNNL physical chemist who worked on the study.

Methods:

The team began by synthesizing a variety of ionic gold clusters in solution. The clusters had 7, 8 or 9 gold atoms and 6 or 7 triphenylphosphine ligands. Their chemical formulas were Au7L62+, Au8L62+, Au8L72+ and Au9L72+ (Au = gold, L = ligand). They filtered out the clusters of interest one by one in the gas phase using mass spectrometry. “We isolate clusters of the exact size that we want,” said Johnson. “In solution, this is very challenging to accomplish — so measurements are typically made on poorly defined distributions of particles.”

Next, they collided the clusters they selected with a special surface inside the mass spectrometer in a process known as surface-induced dissociation. The instrument showed the fragments produced when the clusters fragmented at different collision energies and times. Using a unique modeling approach developed by Laskin, they determined the energy involved in breaking the clusters apart and whether each route to fragmentation is rapid or slow for a specific cluster.

They found the clusters dissociate through 1 of 3 competing pathways. The particles may break

  • With the loss of an uncharged phosphine ligand.
  • Through asymmetrical fission, with a gold atom and two ligands breaking off.
  • Through more symmetrical fission, with two fragments having nearly the same number of gold atoms and ligands.

The team showed that a cluster containing 8 gold atoms and 6 ligands is exceptionally stable compared to other clusters. It turns out that this cluster is also the predominant species formed during the early stages of reduction synthesis in solution. This observation demonstrates that experiments with gas-phase ions are indispensable for understanding the thermochemistry of complex processes occurring in solution.

The study also provides theorists with benchmark values for their calculations and simulations of ligated gold clusters. Experimental benchmarks give theorists important complementary information that aids them in selecting the most computationally efficient and accurate methods.

What’s Next:

The team expects that the surface-induced dissociation experiments will play an increasing role in understanding the initial steps of cluster nucleation and growth in solution. They are currently examining different ligated clusters to understand how the spatial arrangement of the atoms in the ligands alters the abundance of clusters formed in solution and their stability in the gas phase.


Reference: Johnson GE, T Priest, and J Laskin. 2014. “Size-dependent Stability toward Dissociation and Ligand Binding Energies of Phosphine Ligated Gold Cluster Ions.” Chemical Science 5:3275-3286. DOI: 10.1039/C4SC00849A


Source: Pacific Northwest National Laboratory

 

 

 

Reducing Energy Costs with Better Batteries


3adb215 D BurrisA better battery—one that is cheap and safe, but packs a lot of power—could lead to an electric vehicle that performs better than today’s gasoline-powered cars, and costs about the same or less to consumers.  Such a vehicle would reduce the United States’ reliance on foreign oil and lower energy costs for the average American, so one of the Department of Energy’s (DOE’s) goals is to fund research that will revolutionize the performance of next-generation batteries.

In honor of DOE’s supercomputing month, we are highlighting some of the ways researchers are using supercomputers at the National Energy Research Scientific Computing Center (NERSC) are working to achieve this goal.

New Anode Boots Capacity of Lithium-Ion Batteries

Lithium-ion batteries are everywhere— in smart phones, laptops, an array of other consumer electronics, and electric vehicles. Good as they are, they could be much better, especially when it comes to lowering the cost and extending the range of electric cars. To do that, batteries need to store a lot more energy.

Using supercomputers at NERSC, Berkeley Lab researchers developed a new kind of anode—energy storing component—that is capable of absorbing eight times the lithium of current designs. The secret is a tailored polymer that conducts electricity and binds closely to lithium storing particles. The researchers achieved this result by running supercomputer calculations of different promising polymers until they found the perfect one. This research is an important step toward developing lithium-ion batteries with eight times their current capacity.

After more than a year of testing and many hundreds of charge-discharge cycles, Berkeley researchers found that their anode maintained its increased energy capacity.  This is a significant improvement from many lithium-ion batteries on the market today, which degrade as they recharge. Best of all, the anodes are made from low-cost materials that are also compatible with standard lithium battery manufacturing technologies.

Read More: https://www.nersc.gov/news-publications/news/science-news/2011/a-better-lithium-ion-battery-on-the-way/

Engineering Better Energy Storage

One of the biggest weaknesses of today’s electric vehicles is battery life—most cars can only go about 100-200 miles between charges. But researchers hope that a new type of battery, called the lithium-air battery, will one day lead to a cost-effective, long-range electric vehicles that could travel 300 miles or more between charges.

Using supercomputers at NERSC and powerful microscopes, a team of researchers from the Pacific Northwest National Laboratory (PNNL) and Princeton University built a novel graphene membrane that could produce a lithium-air battery with the highest-energy capacity to date. Because the material does not rely on platinum or other precious metals, its potential cost and environmental impact are significantly less than current technology.

Read More: https://www.nersc.gov/news-publications/news/science-news/2012/bubbles-help-break-energy-storage-record-for-lithium-air-batteries/

Promise for Onion-Like Carbons as Supercapacitors

The two most important electrical storage technologies on the market today are batteries and capacitors—both have their pluses and minuses. Batteries can store a lot of energy, but have slow charge and discharge rates. While capacitors generally store less energy but have very fast (nearly instant) charge and discharge rates, and last longer than rechargeable batteries. Developing technologies that combine the optimal characteristics of both will require a detailed understanding of how these devices work at the molecular level. That’s where supercomputers come in handy.

One promising electrical storage device is the supercapacitator, which combines the fast charging and discharging rates of conventional capacitators, as well as the high-power density, high-capacitance (ability to store electrical charge), and durability of a battery. Today supercapacitators power electric vehicles, portable electronic equipment and various other devices. Despite their use in the marketplace, researchers believe these energy storage devices could perform much better. One area that they are hoping to improve is the device’s electrode, or a conductor through which electricity enters or leaves.

Most supercapacitor electrodes are made of carbon-based materials, but one promising material yet to be explored is graphene. The strongest material known, graphene also has unique electrical, thermal, mechanical and chemical properties. Using supercomputers at NERSC, scientists ran simulations to understand how the shape of a graphene electrode affects its electrical properties. They hope that one-day this work will inspire the design of supercapacitators that can hold a much more stable electric charge.

Read More: http://www.nersc.gov/news-publications/news/science-news/2012/why-onion-like-carbons-make-high-energy-supercapacitors/

A Systematic Approach to Battery Design

New materials are crucial for building advanced batteries, but today the development cycle is too slow. It takes about 15 to 18 years to go from conception to commercialization. To speed up this process, a team of researchers from Lawrence Berkeley National Laboratory (Berkeley Lab) and the Massachusetts Institute of Technology (MIT) created a new computational tool called the Materials Project, which is hosted at NERSC.

The Materials Project uses supercomputers at NERSC, Berkeley Lab and the University of Kentucky to characterize the properties of inorganic compounds—such as stability, voltage, capacity and oxidation state—via computer simulations. The results are then organized into a database with a user-friendly web interface that allows users to easily access and search for the compound that they would like to use in their new material design. Knowing the properties of a compound beforehand allows researchers to quickly assess whether their idea will be successful, without spending money and time developing prototypes and experiments that will eventually lead to a dead-end.

In early 2013, DOE pledged $120 million over five years to establish the Joint Center for Energy Storage Research (JCESR). As part of this initiative, the Berkeley Lab and MIT researchers will run simulations at NERSC to predict the properties of electrolytes—a liquid. The results will be incorporated into a database similar to the Materials Project. Eventually researchers will be able to combine the JCESR database with the Materials Project to get a complete scope of battery components. Together, these resources allow scientists to employ a systematic and predictive approach to battery design.

Read More: https://www.nersc.gov/news-publications/news/science-news/2012/nersc-helps-develop-next-gen-batteries/

For more information about how Berkeley Lab is celebrating DOE supercomputing month, please visit: http://cs.lbl.gov/news-media/news/2013/supercomputing-sept-2013/


About Berkeley Lab Computing Sciences

The Lawrence Berkeley National Laboratory (Berkeley Lab) Computing  Sciences organization provides the computing and networking resources  and expertise critical to advancing the Department of Energy’s research  missions: developing new energy  sources, improving energy efficiency, developing new materials and  increasing our understanding of ourselves, our world and our universe. ESnet, the Energy Sciences Network, provides the high-bandwidth, reliable connections that link scientists at 40 DOE research sites to each other and to experimental facilities and supercomputing centers around the country. The National Energy Research  Scientific Computing Center (NERSC) powers the discoveries of 5,500 scientists at national laboratories and universities, including those at Berkeley Lab’s Computational Research Division (CRD). CRD  conducts research and development in mathematical modeling and  simulation, algorithm design, data storage, management and analysis,  computer system architecture and high-performance software  implementation.

New Center for Sustainable Nanotechnology to study environmental footprint of nanoparticles


Posted: Nov 29th, 2012

(Nanowerk News) Northwestern University has joined  forces with four Midwestern universities and a national laboratory to establish  the Center for Sustainable Nanotechnology, which this fall received  funding from the National Science Foundation.
Chemists, environmental engineers and freshwater scientists will  work on developing a deeper understanding of nanotechnology’s environmental  footprint and potential toxicity — areas little understood, despite a rapid  increase of nanomaterials used in consumer products, from cellphones and laptops  to sunscreen and beer bottles.
“We need to know how the tiny particles interact with their  environment, and this requires advanced imaging and spectroscopic tools that can  see where no eye has seen before,” said Franz M. Geiger, a professor of chemistry in the Weinberg  College of Arts and Sciences who is leading the Northwestern team.
“And the nanoparticles must be studied without taking them out  of their biogeochemical environment or modifying them for analysis,” he said. “This is an extremely daunting challenge but one we relish.”
Geiger’s team includes Stephanie Walter, Julianne Troiano and  Laura Olenick, all doctoral students in his lab. They will utilize their unique  nonlinear optics laboratory to develop new imaging techniques and provide  testing grounds for nanoparticles created by other center members.
Robert Hamers, a professor of chemistry at the University of  Wisconsin-Madison, is director of the Center for Sustainable Nanotechnology.  Other center members are the University of Minnesota, the University of  Wisconsin-Milwaukee, the University of Illinois and Pacific Northwest National  Laboratory.
“Our center — involving the expertise of researchers at six  different institutions — takes ample advantage of synergy, which, by  definition, produces effects that cannot be produced by summing up the  individual parts,” Geiger said.
Center researchers will focus on understanding how the surfaces of new as well as aged or weathered nanoparticles interact at the molecular level with cell membranes and what kind of biochemical pathways are triggered when these interactions occur. The findings ultimately could help inform the development of federal regulations.
In addition to the molecular studies, the researchers will study  two freshwater organisms, a water flea and a bacterium, feeding them  nanoparticles and tracking the particles using methods to be developed in the  center. The biochemical pathways will be studied to determine if the  nanoparticles have any toxic effects on the organisms.
Some of the nanomaterials produce a signal by lighting up when  light of a certain color is shined on them, allowing the particles to be imaged  inside living organisms. Geiger and his team will apply nonlinear optical  approaches to study a subset of these materials: those that can be accessed  using the suite of ultrafast laser systems available in his laboratory.
The Center for Sustainable Nanotechnology received a three-year,  $1.75 million Phase 1 Center for Chemical Innovation grant from the National  Science Foundation (NSF) this fall. Following the initial phase, the researchers  will have the opportunity to apply to the NSF for a much larger grant to  continue their work.
Geiger’s research with the new center connects to Northwestern’s  strategic plan goals of discovering creative solutions to problems that will  improve lives, communities and the world as well as focusing on nanoscience, one  of Northwestern’s 10 areas of greatest strength.
Source: Northwestern  University

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