15 Nov 2013
Scientists collaborate to maximize energy gains from tiny nanoparticles
“We are developing a new ‘micro-reactor’ that enables us to explore many aspects of catalytic function using multiple approaches at Brookhaven’s National Synchrotron Light Source (NSLS), the soon-to-be-completed NSLS-II, and the Center for Functional Nanomaterials (CFN),” said Stach, who works at the CFN. “This approach lets us understand multiple aspects of how catalysts work so that we can tweak their design to improve their function. This work could lead to big gains in energy efficiency and cost savings for industrial processes.” – Anatoly Frenkel, Yeshiva University
Sometimes big change comes from small beginnings. That’s especially true in the research of Anatoly Frenkel, a professor of physics at Yeshiva University, who is working to reinvent the way we use and produce energy by unlocking the potential of some of the world’s tiniest structures: nanoparticles.
“The nanoparticle is the smallest unit in most novel materials, and all of its properties are linked in one way or another to its structure,” said Frenkel. “If we can understand that connection, we can derive much more information about how it can be used for catalysis, energy, and other purposes.”
“This work could lead to big gains in energy efficiency and cost savings for industrial processes.”
— Eric Stach, CFN
Frenkel is collaborating with materials scientist Eric Stach and others at the U.S. Department of Energy’s Brookhaven National Laboratory to develop new ways to study how nanoparticles behave in catalysts—the “kick-starters” of chemical reactions that convert fuels to useable forms of energy and transform raw materials to industrial products.
“We are developing a new ‘micro-reactor’ that enables us to explore many aspects of catalytic function using multiple approaches at Brookhaven’s National Synchrotron Light Source (NSLS), the soon-to-be-completed NSLS-II, and the Center for Functional Nanomaterials (CFN),” said Stach, who works at the CFN. “This approach lets us understand multiple aspects of how catalysts work so that we can tweak their design to improve their function. This work could lead to big gains in energy efficiency and cost savings for industrial processes.”
High-tech tools for science
Until now, the methods for understanding catalytic properties could only be used one at a time, with the catalyst ending up in a different state for each of the experiments. This made it difficult to compare information obtained using the different instruments. The new micro-reactor will employ multiple techniques—microscopy, spectroscopy, and diffraction—to examine different properties of catalysts simultaneously under operating conditions. By keeping particles in the same structural and dynamic state under the same reaction conditions, the micro-reactor will give scientists a much better sense of how they function.
“These developments have resulted from the combination of unique facilities available at Brookhaven,” said Frenkel. “By working closely with Eric, we realized that there was a way to make both x-ray and electron-based methods work in a truly complementary fashion.
Each technique has strengths, Stach explained. “At the NSLS, using powerful beams of x-rays, we can tell how the entire group of nanoparticles behaves, while electron microscopy at the CFN lets us see the atomic structure of each nanoparticle. By having both of these views of the catalysts we can more clearly understand the relationship between catalyst structure and function.”
Said Frenkel, “It was very satisfying for us to conduct the first tests with the reactor at each facility and receive positive results. I am particularly grateful to Ryan Tappero, the scientist who runs NSLS beamline X27A, for his expert help with x-ray data acquisition.”
Frenkel has had an ongoing collaboration with scientists at Brookhaven. Last year, with post-doctoral research associate Qi Wang, Frenkel and Stach measured properties of nanoparticles using the x-rays produced by the NSLS as well as atomic-scale imaging with electrons at the CFN. As reported in a paper published in the Journal of the American Chemical Society earlier this year, they discovered that rather than changing completely from one state to another at a certain temperature and size, as had been previously believed, there is a transition zone between states when particles are changing forms.
“This is of significance fundamentally because until now, the structures were known to merely change from one form to another—they were never envisioned to coexist in different forms,” Frenkel said. “With our information we can explain why catalysts often don’t work as expected and how to improve them.”
Training for young scientists
The collaboration also offers opportunities for students to experience the challenges of research, giving them access to the world-class tools at Brookhaven. Frenkel’s undergraduate students at Yeshiva University’s Stern College for Women help with measurements, data analysis, and interpretation, and many have already accompanied him to Brookhaven to assist in his work using NSLS and other cutting-edge instruments.
“I’m giving them firsthand experience about what a researcher’s life is like early on as they conduct first-rate research,” said Frenkel. “This experience opens doors to any field they want to be in.”
Alyssa Lerner, a pre-engineering major who has been working with Frenkel at Brookhaven, said the research “has helped me develop skills like computational analysis and critical thinking, which are essential in any scientific field. The hands-on experimental experience has given me a better understanding of how the scientific community operates, helping me make more informed career-related choices as I continue to advance my education.”
Pairing up students and mentors to advance education and making use of complementary imaging techniques to enhance energy efficiency—just two of the positive outcomes of this successful collaboration.
“By bringing together multiple complementary techniques to illuminate the same process we’re going to understand how nanomaterials work,” Frenkel said. “Ultimately, this research will create a better way of using, storing, and converting energy.”
The CFN and NSLS facilities at Brookhaven Lab are supported by the Department of Energy’s Office of Science. The collaborative work of Frenkel and Stach is funded by the Office of Science and Brookhaven’s Laboratory Directed Research and Development program.
The Center for Functional Nanomaterials is one of five DOE Nanoscale Science Research Centers (NSRCs), national user facilities for interdisciplinary research at the nanoscale, supported by the DOE Office of Science. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE’s Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge and Sandia and Los Alamos National Laboratories. For more information about the DOE NSRCs, please visit http://science.energy.gov.
The National Synchrotron Light Source (NSLS) provides intense beams of infrared, ultraviolet, and x-ray light for basic and applied research in physics, chemistry, medicine, geophysics, and environmental and materials sciences. Supported by the Office of Basic Energy Sciences within the U.S. Department of Energy, the NSLS is one of the world’s most widely used scientific facilities. For more information, visit http://www.nsls.bnl.gov.
DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov
This story incorporates content from a piece by Perel Skier on the Yeshiva University news blog.
14 Nov 2013
|(Nanowerk News) Researchers have created tiny protein tubes named after the Roman god Janus which may offer a new way to accurately channel drugs into the body’s cells.|
|Using a process which they liken to molecular Lego, scientists from the University of Warwick and the University of Sydney have created what they have named ‘Janus nanotubes’ – very small tubes with two distinct faces. The study is published in the journal Nature Communications (“Janus cyclic peptide–polymer nanotubes”).|
|They are named after the Roman god Janus who is usually depicted as having two faces, since he looks to the future and the past.|
|The Janus nanotubes have a tubular structure based on the stacking of cyclic peptides, which provide a tube with a channel of around 1nm – the right size to allow small molecules and ions to pass through.|
|Attached to each of the cyclic peptides are two different types of polymers, which tend to de-mix and form a shell for the tube with two faces – hence the name Janus nanotubes.|
|The faces provide two remarkable properties – in the solid state, they could be used to make solid state membranes which can act as molecular ‘sieves’ to separate liquids and gases one molecule at a time. This property is promising for applications such as water purification, water desalination and gas storage.|
|In a solution, they assemble in lipids bilayers, the structure that forms the membrane of cells, and they organise themselves to form pores which allow the passage of molecules of precise sizes. In this state they could be used for the development of new drug systems, by controlling the transport of small molecules or ions inside cells.|
|Sebastien Perrier of the University of Warwick said: “There is an extraordinary amount of activity inside the body to move the right chemicals in the right amounts both into and out of cells.|
|“Much of this work is done by channel proteins, for example in our nervous system where they modulate electrical signals by gating the flow of ions across the cell membrane.|
|“As ion channels are a key component of a wide variety of biological process, for example in cardiac, skeletal and muscle contraction, T-cell activation and pancreatic beta-cell insulin release, they are a frequent target in the search for new drugs.|
|“Our work has created a new type of material – nanotubes – which can be used to replace these channel processes and can be controlled with a much higher level of accuracy than natural channel proteins.|
|“Through a process of molecular engineering – a bit like molecular Lego – we have assembled the nanotubes from two types of building blocks – cyclic peptides and polymers.|
|“Janus nanotubes are a versatile platform for the design of exciting materials which have a wide range of application, from membranes – for instance for the purification of water, to therapeutic uses, for the development of new drug systems.”|
|Source: University of Warwick|
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29 Oct 2013
(Nanowerk Spotlight) Colloidal quantum dot (CQD) nanocrystals are attractive materials for optoelectronics, sensing devices and third generation photovoltaics, due to their low cost, tunable bandgap – i.e. their optical absorption can be controlled by changing the size of the CQD nanocrystal – and solution processability. This makes them attractive candidate materials for cheap and scalable roll-to-roll printable device fabrication technologies.
One key impediment that currently prevents CQDs from fulfilling their tremendous promise is that all reports of high efficiency devices were from CQDs synthesized using manual batch synthesis methods (in classical reaction flasks).