Science Current Events | Science News | Brightsurf.com
 
Email a Friend Send to a friend
Printer Friendly Print A new approach to engineering for extreme environments

A new approach to engineering for extreme environments

June 30, 2009

Composite materials such as fiberglass, which take on a mix of properties of their constituent compounds, have been around for decades. Now, an MIT materials scientist is taking composites to the nanoscale, where entirely new properties, not found in any of the original compounds, can emerge.

Michael Demkowicz, an assistant professor in MIT's Department of Materials Science and Engineering, is part of a team based at Los Alamos National Laboratory that recently received a federal Energy Frontier Research Centers grant to develop nanocomposite materials that can endure high temperatures, radiation and extreme mechanical loading. The ultimate goal is to use these materials in energy applications including nuclear power, fuel cells, solar energy and carbon sequestration.




"All sectors of energy production need materials that can withstand extreme conditions," says Demkowicz, whose model offers a new approach to designing nanocomposites with desirable traits.

There are many models that can take a proposed material structure and predict how it will behave. However, such trial-and-error approaches still require repeated cycles of manufacture and testing and are "an extremely costly and time-consuming way to come up with a new material," says Demkowicz.

His model tackles what materials scientists call "the inverse problem" -- specifying a desired set of properties and then predicting which structures will deliver them -- and could dramatically speed up the design process.
Radiation resistance

Demkowicz' first target is radiation-resistant materials, which could improve the efficiency and safety of nuclear power plants.

Normally, when metals are exposed to radiation, high-energy particles such as neutrons bump into individual atoms and knock them out of their crystal lattice. Like billiard balls, the displaced atoms bump into neighboring atoms, spreading damage in the form of "vacancies" (holes where an atom is missing), and "interstitials" (an extra atom squeezed in where it shouldn't be). Clusters of these defects can make the material brittle and weak.

The key to making nanocomposite materials resistant to radiation damage lies in the interfaces between layers of different materials. As the layers become thinner, the interfaces play a more dominant role in the material properties because the ratio of interface area to the material's total volume becomes larger. These interfaces give rise to novel properties not found in the original materials.

In some nanocomposites, vacancies and interstitials can get trapped at interfaces, where they have a higher likelihood of meeting. When that happens, the extra atom fills in the hole and the crystal structure is restored. Under some conditions it can appear as if there was no radiation damage remaining at all, says Demkowicz.

Materials resistant to radiation damage could eventually be used to line nuclear reactors, a function now performed by stainless steel. That could extend the lifetime of nuclear reactors and allow them to operate under higher radiation doses. Whereas current reactors consume only about one percent of their fuel, these improved reactors could burn a higher percentage of nuclear fuel and leave behind less waste.

Demkowicz has used his model, which is based on reproducing the mechanical interactions of groups of atoms, to design a nanocomposite with interfaces that resist radiation. The material, described in Physical Review Letters last year, is a mix of copper and the metal niobium and could not be used in a nuclear reactor because it absorbs neutrons and becomes radioactive. However, now that he knows copper-niobium is resistant to radiation damage, Demkowicz can use his modeling techniques to look for other materials that share that property.

Once a promising candidate is identified, it takes several years of testing before a new material can be approved for use in a nuclear reactor, so it will likely be at least a decade before any of his potential new materials can be used, says Demkowicz.

In addition to Demkowicz, several other MIT researchers are involved in the new Energy Frontier Research Centers. MIT will host two of the centers -- the Center for Excitonics, led by Associate Professor Marc Baldo, and the Solid-State Solar-thermal Energy Conversion Center, led by Professor Gang Chen.

Massachusetts Institute of Technology



Related Nanoscale Current Events and Nanoscale News Articles Nanoscale Current Events and Nanoscale News RSS Nanoscale Current Events and Nanoscale News RSS
Magnetic nanoparticles to simultaneously diagnose, monitor and treat
Whether it's magnetic nanoparticles (mNPs) giving an army of 'therapeutically armed' white blood cells direction to invade a deadly tumour's territory, or the use of mNPs to target specific nerve channels and induce nerve-led behaviour (such as the life-dependant thumping of our hearts), mNPs have come a long way in the past decade.

Breakthrough in industrial-scale nanotube processing
Rice University scientists today unveiled a method for the industrial-scale processing of pure carbon-nanotube fibers that could lead to revolutionary advances in materials science, power distribution and nanoelectronics.

LANL Roadrunner simulates nanoscale material failure
Very tiny wires, called nanowires, made from such metals as silver and gold, may play a crucial role as electrical or mechanical switches in the development of future-generation ultrasmall nanodevices.

Transforming Nanowires Into Nano-Tools Using Cation Exchange Reactions
A team of engineers from the University of Pennsylvania has transformed simple nanowires into reconfigurable materials and circuits, demonstrating a novel, self-assembling method for chemically creating nanoscale structures that are not possible to grow or obtain otherwise.

Caltech scientists first to trap light and sound vibrations together in nanocrystal
Researchers at the California Institute of Technology (Caltech) have created a nanoscale crystal device that, for the first time, allows scientists to confine both light and sound vibrations in the same tiny space.

Nanowire biocompatibility in the brain: So far so good
The biological safety of nanotechnology, in other words, how the body reacts to nanoparticles, is a hot topic. Researchers at Lund University in Sweden have managed for the first time to carry out successful experiments involving the injection of so-called 'nanowires.'

Caltech scientists solve decade-long mystery of nanopillar formations
Scientists at the California Institute of Technology (Caltech) have uncovered the physical mechanism by which arrays of nanoscale (billionths-of-a-meter) pillars can be grown on polymer films with very high precision, in potentially limitless patterns.

Harvard scientists bend nanowires into 2-D and 3-D structures
Taking nanomaterials to a new level of structural complexity, scientists have determined how to introduce kinks into arrow-straight nanowires, transforming them into zigzagging two- and three-dimensional structures with correspondingly advanced functions.

Smallest Nanoantennas for High-speed Data Networks
More than 120 years after the discovery of the electromagnetic character of radio waves by Heinrich Hertz, wireless data transmission dominates information technology.

0.2 second test for explosive liquids
Since a failed terrorist attack in 2006, plane passengers have not been able to carry bottles of liquid through security at airports, leaving some parched at the airport and others having expensive toiletries confiscated, but work by a group of physicists in Germany is paving the way to eliminate this necessary nuisance.
More Nanoscale Current Events and Nanoscale News Articles
Nanoscale: Visualizing an Invisible World

Nanoscale: Visualizing an Invisible World
by Kenneth S. Deffeyes (Author), Stephen E. Deffeyes (Author)

The world is made up of structures too small to see with the naked eye, too small to see even with an electron microscope. Einstein established the reality of atoms and molecules in the early 1900s. How can we see a world measured in fractions of nanometers? (Most atoms are less than one nanometer, less than one-billionth of a meter, in diameter.) This beautiful and fascinating book gives us a tour of the invisible nanoscale world. It offers many vivid color illustrations of atomic structures, each accompanied by a short, engagingly written essay. The structures advance from the simple (air, ice) to the complex (supercapacitor, rare earth magnet). Each subject was chosen not in search of comprehensiveness but because it illustrates how atomic structure creates a property (such as...

Introduction to Nanoscale Science and Technology (Nanostructure Science and Technology)

Introduction to Nanoscale Science and Technology (Nanostructure Science and Technology)
by Massimiliano Di Ventra (Editor), Stephane Evoy (Editor), James R. Heflin (Editor)

Nanoscale science and technology is a young, promising field that encompasses a wide range of disciplines including physics, chemistry, biology, electrical engineering, chemical engineering, and materials science. With rapid advances in areas such as molecular electronics, synthetic biomolecular motors, DNA-based self-assembly, and manipulation of individual atoms, nanotechnology has captured the attention and imagination of researchers and the general public. Introduction to Nanoscale Science and Technology provides a broad and thorough introduction that is aimed specifically at undergraduate seniors and early graduate students in all of the disciplines enumerated above. It will also be of value to academic, industrial, and government researchers interested in a primer in the field. ...

SpillKlenz

SpillKlenz
by NanoScale Corporation

Odor eliminating liquid absorbent facilitates immediate clean-up of liquids by quickly absorbing spills and neutralizing the accompanying odors.

SpillKlenz Travel Kit

SpillKlenz Travel Kit
by NanoScale Corporation

Odor eliminating liquid absorbent kit facilitates immediate clean-up of liquids by quickly absorbing spills and neutralizing the accompanying odors. The kit provides spill control and containment in confined spaces where clean-up is inconvenient. Kit includes 2 revolutionary odor neutralizing sorbent packets, 2 sanitizing wipes, 2 disposal bags, 1 scoop and scraper, and 1 pair of non-latex gloves.

Nanoscale

Nanoscale
Geordie Haley (Primary Contributor)



Electrical Transport in Nanoscale Systems

Electrical Transport in Nanoscale Systems
by Massimiliano Di Ventra (Author)

This graduate textbook provides an in-depth description of the transport phenomena relevant to systems of nanoscale dimensions. The different theoretical approaches are critically discussed, with emphasis on their basic assumptions and approximations. The book also covers information content in the measurement of currents, the role of initial conditions in establishing a steady state, and the modern use of density-functional theory. Topics are introduced by simple physical arguments, with particular attention to the non-equilibrium statistical nature of electrical conduction, and followed by a detailed formal derivation. This textbook is ideal for graduate students in physics, chemistry, and electrical engineering.

No Small Matter: Science on the Nanoscale

No Small Matter: Science on the Nanoscale
by Felice C. Frankel (Author), George M. Whitesides (Author)

A small revolution is remaking the world. The only problem is, we can’t see it. This book uses dazzling images and evocative descriptions to reveal the virtually invisible realities and possibilities of nanoscience. An introduction to the science and technology of small things, No Small Matter explains science on the nanoscale.

Authors Felice C. Frankel and George M. Whitesides offer an overview of recent scientific advances that have given us our ever-shrinking microtechnology—for instance, an information processor connected by wires only 1,000 atoms wide. They describe the new methods used to study nanostructures, suggest ways of understanding their often bizarre behavior, and outline their uses in technology. This book explains the various means of making...

OdorKlenz Laundry, Medium

OdorKlenz Laundry, Medium
by NanoScale Corporation

OdorKlenz Laundry is an odor elimination laundry additive which eliminates tough odors regular detergents leave behind.

Cellular Nanoscale Sensory Wave Computing

Cellular Nanoscale Sensory Wave Computing
by Chagaan Baatar (Editor), Wolfgang Porod (Editor), Tamas Roska (Editor)

This book is a result of a Multidisciplinary University Research Initiative (MURI) project that has been funded by the Office of Naval Research and completed recently. The results manifest a new way of thinking about sensory computing, as well as being one of the first successful attempts to bridge the gap between nanoscale (smaller than 100 nm) devices and CMOS integrated circuits with stored programmable algorithms and software on the system level. In this book the emerging and converging architecture of morphic cellular wave computers based on the concept of Cellular Neural/Nonlinear Network (CNN) is introduced in a practical way. The book also discusses the architecture and operation of a vision system on a chip (VSoC) which is in the first single chip cellular wave computer.



Environmental Surfaces and Interfaces from the Nanoscale to the Global Scale

Environmental Surfaces and Interfaces from the Nanoscale to the Global Scale
by Patricia Maurice (Author)

An advanced exploration ofwater-rock interactions

Based on the author's fifteen years of teaching and tried-and-tested experiences in the classroom, here is a comprehensive exploration of water-rock interactions. Environmental Surfaces and Interfaces from the Nanoscale to the Global Scale covers aspects ranging from the theory of charged particle surfaces to how minerals grow and dissolve to new frontiers in W-R interactions such as nanoparticles, geomicrobiology, and climate change.

Providing basic conceptual understanding along with more complex subject matter, Professor Patricia Maurice encourages students to look beyond the text to ongoing research in the field. Designed to engage the learner, the book features: Numerous case studies to...

© 2009 BrightSurf.com