You are browsing the archives of 2009 December.

A chemist has created an ‘upcycling’ method of turning the disposable plastic bags into carbon nanotubes. The research is published in The Journal of Environmental Monitoring.

Vilas Ganpat Pol at Argonne National Lab developed the bag-to-nanotube technique and converts high or low-density polyethylene (HDPE and LDPE) into valuable multiwalled carbon nanotubes.

The nanotubes have even been used to make lithium-ion batteries.

Pol made the nanotubes by cooking 1-gram pieces of HDPE or LDPE at 700 C for 2 hours in the presence of a cobalt acetate catalyst and then letting the mixture cool gradually.

Above 600 C, the chemical bonds within the plastic completely break down and multiwalled carbon nanotubes grow on the surface of the catalytic particles.

A lot of catalyst is needed to get good results - about one-fifth of the weight of the plastic being converted - and it cannot easily be recovered afterward.

However, Pol said that this is still one of the cheapest and environmentally friendly ways yet found to grow nanotubes.

“Other methods generally require a vacuum to avoid oxygen interaction with the catalyst as well as with the system. In my new reaction there is no vacuum - the formation of oxide is inhibited due to the presence of a continuous reducing hydrocarbon atmosphere at 700 C,” he said.

Individual pieces of the catalyst become trapped inside forests of newly grown nanotubes. However, Pol has shown the nanotubes can be used as is without further processing to cut them free.

“I have used the as-prepared cobalt-encapsulated nanotubes as an anode material for lithium-ion batteries and they work fantastically. The specific capacity of my carbon nanotubes is higher than commercial nanotubes,” he said.

He thinks that might be down to slight imperfections in the usually-regular structure of the nanotubes, created by the reducing atmosphere during fabrication.

Pol said that the cobalt impurities also make the nanotubes suitable for use in lithium-air batteries, because the cobalt is converted to cobalt oxides that perform as catalysts to help the reactions of ions in the battery that let current flow.

He has patented the use of the cobalt-containing nanotubes in both lithium-ion and lithium-air batteries.

“The cobalt is not an impurity, it is an asset,” he said.

Share

According to a press release, a Cornell research team has invented a simple way to grow graphene directly onto a silicon wafer. The work was published online Oct. 27 in the journal Nano Letters.

Predictions have been made that graphene will eventually be a substitute for silicon in electronics, but making it in large quantities is a challenge. Scientists have made progress since the days when they used scotch tape to pull off a layer of graphene from graphite, but most contemporary methods aren’t yet robust enough for large-scale manufacturing, especially for the applications that require graphene with varying numbers of layers at random positions.

“You can imagine trying to peel a piece of shrink wrap off a dish to put it on a new dish - it’s going to be messy,” said lead researcher Jiwoong Park, Cornell assistant professor of chemistry and chemical biology.

The Cornell group’s new method is to grow the graphene directly onto silicon wafers coated with a special evaporated copper film. They then cut the graphene films into their desired shapes using such standard methods as photolithography. Finally, they move the underlying copper with a chemical solution. What is left is a graphene film that draped down over the silicon wafer with little defect.

“Once the graphene is made on top of this wafer, you can apply any thin-film processing technique,” Park said.

The team is now experimenting with growing four-inch wafers, which would further demonstrate the manufacturing potential of graphene-based electronics.

Share

The DOE has paid out only 8% of its Recovery Act funds:

And, the National Science Foundation has paid out only 4% of its Recovery Act funds:

At least one commentator (see here) thinks my expectations are flawed about the speed of the funding from DOE and NSF. I continue to disagree.

First, my expectations are that, since these are not normal times, everyone in the various buy/sell/hire/approve chains better be working damn hard to expedite every step of the process. Old timelines should not be the standard for measurement.

Second, the commentator’s example is silly and empirical at best. If what you are saying is that the real problem is the bottlenecks with getting orders filled, then you aren’t talking to many people in the business of supplying this equipment. The ones we talk to, daily and weekly, are hurting and waiting for the orders to come in. Many businesses have already failed or had to sell out for bargain basement prices. Others are teetering on the  brink.

Third, what has to go on in the buy/sell/hire/approve chain in DOE is not significantly different than what happens in federal agencies. Yes, proposals have to be reviewed. Yes, equipment has to be ordered, built and received, blah, blay blah. But - somehow - nearly every other major federal agency has been able to pay out 20%+ of their recovery monies, some are nearing 90% payouts, and yet the DOE and NSF are stuck at less than 10%. HHS, for example, has $57billion available and has paid out $41 billion. HUD has $11 billion and paid out $2 billion. Education had $69 billion and paid out $22 billion.

Spend some time looking poking around recovery.gov and you can’t help get a sense that something is really gumming up the works at DOE and NSF.

Share

It’s a bird! It’s a plane! It’s a … van with solar panel wings?

As the United Nations Climate Change Conference in Copenhagen gets under way, Sanyo has unveiled its latest green-energy machine. Scheduled to go on display tomorrow (Dec. 10) at the Eco Products 2009 International Exhibition in Tokyo, the Solar Electric Vehicle is powered by Sanyo solar panels and lithium-ion batteries.

The van only takes 16 hours to charge (able to travel a 130 km distance) via the solar panels, or only eight hours if charged via a 100-volt AC outlet. The Sanyo van will be available for test drives at the company’s Green Energy Park booth at the Tokyo conference this week.

Tall folks - watch your head.

The company will also be demoing its “eneloop” hybrid-electric bicycles and recharging bike “parking lot” system at its booth. Sanyo recently showed plans for the bike/lot system that provides self-sustaining bike recharging sites that are powered by solar panels (see below).

Share

Credit: CommonCurrent.com

The Department of Energy’s Advanced Research Projects Agency-Energy announced on Dec. 8 that it is launching a new fellowship project. According to the DOE, ARPA-E is looking to hire (for two-year terms) “highly technical scientists and researchers, who will actively help create the strategic direction and vision of the country’s first agency devoted exclusively to transformational energy technology research and development.”

Those selected to be Fellows will have two main responsibilities. The first is to help ARPA-E’s program directors in program creation; the second is to undertake independent research in promising areas for the agency. ARPA-E’s vision of the program is that Fellows will interact to develop concepts and proposals for high-impact ARPA-E research program areas, prepare related economic analyses, and, ultimately, make recommendations to DOE senior management.

Actually, there will be two tiers to the Fellows program: Fellow and Senior Fellow. All participants are expected to have very strong backgrounds in at least one energy field, and a strong record of scholarship and publication. Senior Fellows will have to have more than three years of deep experience in their field. Postdocs and recent grads (working towards their Ph.D.) would be considered for the entry-level Fellow positions.

“We need the best and the brightest to help shape our nation’s energy future,” said Dr. Majumdar. “The ARPA-E Fellows Program gives us the opportunity to invest in our up and coming researchers and entrepreneurs as we continue to look for creative and inventive approaches to transform the global energy landscape while advancing America’s technology leadership.”

DOE says all will be considered full-time federal employees and will be paid at a competitive salary.

ARPA-E has set up a special webpage with more information and application procedures.

This Fellows announcement follows news that ARPA-E is committing $100 million to fund a second round of “transformational” research projects. Timed to coincide with the Copenhagen climate negotiations, the announcement says ARPA-E is now targeting three new areas on top of the 37 announced in October.

The three new areas receiving attention are

• Electrofuels: ARPA-E is seeking new ways to make liquid transportation fuels that avoid petroleum or biomass, and instead are based on metabolic engineering and synthetic-biological approaches for the efficient conversion of carbon dioxide to liquid transportation fuels. It is particularly interested in proposals that extract energy from “hydrogen, from reduced earth-abundant metal ions, from robust, inexpensive, readily available organic redox active species, or directly from electric current.”

• Innovative Materials & Processes for Advanced Carbon Capture Technologies: The agency is looking for revolutionary technologies that capture carbon dioxide from coal-fired power plants. ARPA-E says it is particularly interested in “low-cost catalysts to enable systems with superior thermodynamics that are not currently practical due to slow kinetics; robust materials that resist degradation from caustic contaminants in flue gas; and advanced capture processes that dramatically reduce the parasitic energy penalties and corresponding increase in the cost of electricity.”

• Batteries for Electrical Energy Storage in Transportation: the agency is looking for ultra-high energy density, low-cost battery technologies that will let the nation meet the goals set forth by the United States Automotive Battery Consortium. The ultimate goal is to “shift transportation energy from oil to the domestically powered U.S. electric grid.”

Share