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(Chem) Flavor and Spices: The Sweet Smell Of Nano-success
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PostPosted: Mon Aug 13, 2007 11:07 am    Post subject: Easing concerns about a promising new medical imaging agent Reply with quote

Easing concerns about a promising new medical imaging agent
13 August 2007
Chemical Research in Toxicology

In a study that eases concern about the toxicity of nanoparticles being considered for use in medical imaging and biomedical research, scientists in North Dakota are reporting “no significant toxic effects” from tests of silica nanoparticles. It is scheduled for the Aug. 20 issue of ACS’ Chemical Research in Toxicology, a monthly journal.

Min Wu and Julia Xiaojun Zhao and colleagues point out that scientists hope to use several kinds of nanomaterials that luminesce, or glow, in clinical medicine and biomedical research. Those materials might, for instance, become a new generation of imaging agents that pinpoint the location of diseased tissue in the body. “However, the question of whether these nanomaterials are toxic to living cells or organisms has not been fully answered,” the researchers explain.

The scientists used laboratory tests on human lung cells to show that luminescent silica nanoparticles did not damage cellular DNA. “Our study indicates that the luminescent silica nanoparticle is a promising labeling reagent for various biomedical applications,” the study concluded, citing the need for further research on potential long-term toxicity.

ARTICLE #2 FOR IMMEDIATE RELEASE “Toxicity of Luminescent Silica Nanoparticles to Living Cells”

DOWNLOAD PDF http://pubs.acs.org/cgi-bin/sa.....001959.pdf
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PostPosted: Mon Aug 20, 2007 8:00 am    Post subject: Carnegie Mellon scientists develop nanogels that enable cont Reply with quote

Carnegie Mellon University
20 August 2007

Carnegie Mellon scientists develop nanogels that enable controlled delivery of carbohydrate drugs

PITTSBURGH—Carnegie Mellon University scientists have developed tiny, spherical nanogels that uniformly release encapsulated carbohydrate-based drugs. The scientists created the nanogels using atom transfer radical polymerization (ATRP), which will ultimately enable the nanogels to deliver more drug directly to the target and to dispense the drug in a time-release manner.

The nanogels — only 200 nanometers in diameter — possess many unique properties that make them ideal drug-delivery tools, according to Daniel Siegwart, a graduate student in University Professor Krzysztof Matyjaszewski’s laboratory at Carnegie Mellon. Siegwart will present his research Monday, Aug. 20 at the 234th national meeting of the American Chemical Society in Boston.

ATRP, a controlled living radical polymerization process, allows chemists to precisely regulate the composition and architecture of the polymers they are creating. Siegwart and colleagues used ATRP in inverse miniemulsion to make nanogels with a uniform network of cross-linked polymer chains within a spherical nanoparticle.

“A uniform mesh size within the nanogels should improve the controlled release of the encapsulated drugs,” said Siegwart. “The major advance of this system is that ATRP allows one to prepare nanogels that are uniform in diameter. The size of the particles can be tuned, and we are currently investigating how nanogels of different sizes enter cells. The results may allow us to better understand the mechanism of endocytosis and to target specific tissues, such as cancer cells that have a more permeable membrane.”

In their most recent advance, the Carnegie Mellon team incorporated the model carbohydrate drug rhodamine isothiocyanate-labeled dextran into the nanogel’s uniform mesh core. When the nanogels degraded, the model carbohydrate drug was released over time. The experiments were carried out with Jung Kwon Oh, a former postdoctoral associate in the Matyjaszewski lab who developed ATRP in inverse miniemulsion.

The new nanogels, which are nontoxic and biodegradable, can also accommodate molecules on their surfaces. During nanogel synthesis, the ATRP process allows scientists to incorporate “targeting groups” on the nanogel surface that can interact with specific receptors, such as those on the surface of a cancer cell. In addition, the nanogels can escape the notice of the body’s immune system, thus prolonging circulation time within the bloodstream.

“The basic composition of the nanogels is based on an analogue of poly(ethylene oxide), a well-established biocompatible polymer that can enhance blood circulation time and prevent clearance by the reticuloendothelial system, the part of the immune system that engulfs and removes foreign objects from the body,” said Siegwart.

In a recent article published in the Journal of the American Chemical Society, the Carnegie Mellon team demonstrated that its novel nanogels could be used to encapsulate doxorubicin, an anticancer drug. When the scientists mixed the doxorubicin-loaded nanogels with HeLa cancer cells in the laboratory, the doxorubicin was released, penetrating the cancer cells and significantly inhibiting their growth. They carried out this work in collaboration with Jeffrey Hollinger, professor of biomedical engineering and biological sciences and director of the Bone Tissue Engineering Center at Carnegie Mellon.


###
This research was funded by the National Science Foundation and the National Institutes of Health. For more on the Matyjaszewski group’s research, visit www.chem.cmu.edu/groups/maty/

About Carnegie Mellon: Carnegie Mellon is a private research university with a distinctive mix of programs in engineering, computer science, robotics, business, public policy, fine arts and the humanities. More than 10,000 undergraduate and graduate students receive an education characterized by its focus on creating and implementing solutions for real problems, interdisciplinary collaboration, and innovation. A small student-to-faculty ratio provides an opportunity for close interaction between students and professors. While technology is pervasive on its 144-acre Pittsburgh campus, Carnegie Mellon is also distinctive among leading research universities for the world-renowned programs in its College of Fine Arts. A global university, Carnegie Mellon has campuses in Silicon Valley, Calif., and Qatar, and programs in Asia, Australia and Europe. For more, see www.cmu.edu
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PostPosted: Mon Sep 10, 2007 1:50 pm    Post subject: Tiny Tubes and Rods Show Promise as Catalysts, Sunscreen Reply with quote

Tiny Tubes and Rods Show Promise as Catalysts, Sunscreen
New ways to make, modify titanium oxide nanostructures for industrial, medical uses

September 10, 2007
Brookhaven National Laboratory

UPTON, NY - Scientists at the U.S. Department of Energy's Brookhaven National Laboratory have developed new ways to make or modify nanorods and nanotubes of titanium oxide, a material used in a variety of industrial and medical applications. The methods and new titanium oxide materials may lead to improved catalysts for hydrogen production, more efficient solar cells, and more protective sunscreens. The research is published in two papers now available online, one in Advanced Materials (August 22, 2007), and the other in the Journal of Physical Chemistry (September 8, 2007).

For the full article:

http://www.bnl.gov/bnlweb/puba.....prID=07-92
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PostPosted: Mon Sep 24, 2007 12:43 pm    Post subject: Scientists get first look at nanotubes inside living animals Reply with quote

Rice University

Scientists get first look at nanotubes inside living animals
Camera captures fluorescent glow from tiny carbon tubes in fruit flies

HOUSTON, Sept. 24, 2007 -- Rice University scientists have captured the first optical images of carbon nanotubes inside a living organism. Using fruit flies, the researchers confirmed that a technique developed at Rice -- near-infrared fluorescent imaging -- was capable of detecting DNA-sized nanotubes inside living fruit flies.

"Carbon nanotubes are much smaller than living cells, and they give off fluorescent light in a way that researchers hope to harness to detect diseases earlier than currently possible," said research co-author Bruce Weisman, professor of chemistry. "In order to do that, we need to learn how to detect and monitor nanotubes inside living tissues, and we must also determine whether they pose any hazards to organisms."

Researchers have studied how carbon nanotubes interact with tissues of rabbits, mice and other animals, but Weisman and co-author Kathleen Beckingham, professor of biochemistry and cell biology, chose something smaller -- the fruit fly Drosophila melanogaster -- to attempt the first-ever detection of nanotubes inside a living animal.

"Drosophila is one of biology's preeminent model organisms," said Beckingham. "We have a wealth of knowledge about the genetic and biochemical workings of fruit flies, and this presents us with unique opportunities to explore the effects and fate of single-walled carbon nanotubes in a living organism."

Weisman and Beckingham's research, which is available online, appeared in the September issue of Nano Letters, the American Chemical Society's journal..

In the study, fruit fly larvae were raised on a yeast paste that contained carbon nanotubes. The flies were fed this food from the time they hatched throughout their initial feeding phase of 4-5 days. Fruit flies are ravenous eaters during this period and gain weight continuously until they are about 200 times heavier than hatchlings. Then they become pupae. As pupae, they do not eat or grow. They mature inside pupal cases and emerge as adult flies.

"Developmentally, the first few days of a fruit fly's life are critical," Beckingham said. "We provided larval flies with a steady diet of food that contained carbon nanotubes and checked their weight just after they emerged from their pupal cases. We found no significant differences in the adult weight of nanotube-fed flies when compared to control groups that were not fed carbon nanotubes."

The nanotube-fed larvae also survived to adulthood just as well as the control group.

Using a custom-built microscope, the team aimed a red laser beam into the fruit flies. This excited a fluorescent glow from the carbon nanotubes, as they emitted near-infrared light of specific wavelengths. The researchers were able to use a special camera to view the glowing nanotubes inside living flies. Videos constructed from these images clearly showed peristaltic movements in the digestive system.

When the researchers removed and examined tissues from the flies, they found the near-infrared microscope allowed them to see and identify individual nanotubes inside the tissue specimens. The highest concentration of nanotubes was found in the dorsal vessel, which is analogous to a main blood vessel in a mammal. Lesser concentrations were found in the brain, ventral nerve cord, salivary glands, trachea and fat. Based on their assays, the team estimates that only about one in 100 million nanotubes passed through the gut wall and became incorporated into the flies' organs.


###
The research was sponsored by the National Science Foundation, Rice University's Center for Biological and Environmental Nanotechnology, the Alliance for NanoHealth and the Welch Foundation. Co-authors include Tonya Leeuw, Michelle Reith, Rebecca Simonette, Mallory Harden, Paul Cherukuri and Dmitri Tsyboulski.
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PostPosted: Tue Oct 30, 2007 12:49 pm    Post subject: Evolution in the Nanoworld Reply with quote

Evolution in the Nanoworld
Max Planck Society
30 October 2007


This week, scientists publish images resolving molecules which have organized themselves into patterns according to size.

The automatic molecular assembly and selection steps exhibited by the molecules, which start as random mixtures, demonstrates a fundamental step in the evolution of life. The organization is activated by instructions which are built-in to the molecules. During assembly, molecules exhibit active selection: those in incorrect positions move to make room for others which fit properly. The molecular-level observation of such self-selection gives, for the first time, direct insight into fundamental steps of the biological evolution from inanimate molecules to living entities. The resulting nanostructures also hold great promise as an efficient avenue to new catalysts, nanotechnologies, and surface applications.

For the full article:

http://www.mpg.de/english/illu.....200710292/
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PostPosted: Wed Oct 31, 2007 2:07 pm    Post subject: Make Way for the Real Nanopod Reply with quote

Make Way for the Real Nanopod: Berkeley Researchers Create First Fully Functional Nanotube Radio
Lawrence Berkeley National Laboratory
31 October 2007


BERKELEY, CA — Make way for the real nanopod and make room in the Guinness World Records. A team of researchers with the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California at Berkeley have created the first fully functional radio from a single carbon nanotube, which makes it by several orders of magnitude the smallest radio ever made.

For the full article:

http://www.lbl.gov/Science-Art.....radio.html
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PostPosted: Mon Nov 12, 2007 2:35 pm    Post subject: Breakthrough toward industrial-scale production of nanodevic Reply with quote

Breakthrough toward industrial-scale production of nanodevices
12 November 2007
Chemistry of Materials

Scientists in Maryland are reporting an important advance toward the long-sought goal of industrial-scale fabrication of nanowire-based devices like ultra-sensitive sensors, light emitting diodes, and transistors for inexpensive, high-performance electronics products. The study is scheduled for the current issue of ACS’ Chemistry of Materials, a bi-weekly journal.

In the report, Babak Nikoobakht points out that existing state-of-the-art assembly methods for nanowire-based devices require complicated, multi-step treatments, painstaking alignments steps, and other processing for nanowires , which are thousands of times smaller than the diameter of a human hair. The goal is to electrically address the coordinates of millions of nanowires on a surface in order to produce the components of electronic circuits. The study describes a new method in which zinc oxide nanowires are grown in the exact positions where nanodevices later will be fabricated, in a way that involves a minimum number of fabrication steps and is suitable for industrial-scale applications. “This method, due to its scalability and ease of device fabrication, goes beyond the current state-of-the-art assembly of nanowire-based devices,” the report states. “It is believed to be an attractive approach for mass fabrication of nanowire-based transistors and sensors and is expected to impact nanotechnology in fabrication of nonconventional nanodevices.”

ARTICLE #4 FOR IMMEDIATE RELEASE “Toward Industrial-Scale Fabrication of Nanowire-Based Devices”

DOWNLOAD PDF http://pubs.acs.org/cgi-bin/sa.....71798p.pdf

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PostPosted: Mon Nov 19, 2007 2:57 pm    Post subject: Magnetic nanoparticles detect and remove harmful bacteria Reply with quote

Magnetic nanoparticles detect and remove harmful bacteria
19 November 2007
Journal of the American Chemical Society

Researchers in Ohio report the development of magnetic nanoparticles that show promise for quickly detecting and eliminating E. coli, anthrax, and other harmful bacteria. In laboratory studies, the nanoparticles helped detect a strain of E. coli within five minutes and removed 88 percent of the target bacteria, the scientists say. Their study is scheduled for the Nov. 7 issue of the Journal of the American Chemical Society, a weekly publication.

Xuefei Huang and colleagues point out that ongoing incidents of produce contamination and the threat of bioterrorist attacks have created an urgent need for quicker, more effective ways to detect bacterial decontamination. To meet that need, they developed a “magnetic glyco-nanoparticle (MGNP),” a unique compound that combines magnetic nanoparticles with sugars.

Sugars (or carbohydrates) on cell surfaces are used by many bacteria to attach to their host cells in order to facilitate infection. The scientists exposed a group of E. coli bacteria to the sugar-coated nano-magnets to mark the microbes so they could be easily identified and removed by a magnetic device. The researchers also used the particles to distinguish between three different E. coli strains.

The study represents “the first time that magnetic nanoparticles have been used to detect, quantify, and differentiate E. coli cells,” the researchers state.

ARTICLE #1 FOR IMMEDIATE RELEASE

“Magnetic Glyco-nanoparticles: A Unique Tool for Rapid Pathogen Detection, Decontamination, and Strain Differentiation”

DOWNLOAD PDF http://pubs.acs.org/cgi-bin/sa.....76086e.pdf
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PostPosted: Fri Nov 30, 2007 3:59 pm    Post subject: Between water and rock -- a new science Reply with quote

Between water and rock -- a new science
30 November 2007
Virginia Tech

Calls into question water analysis results, bioremediation impacts

Blacksburg, Va. -- Water chemistry and mineralogy are scientific fields that have been around long enough to develop extensive knowledge and technologies. The boundary of water and rock, however, is not a thin wet line but the huge new field of nanoparticle science.

Scientists are discovering that aquatic nanoparticles, from 1 to 100 nanometers, influence natural and engineered water chemistry and systems differently than similar materials of a larger size. “Nanoparticles are in an awkward intermediate state, between elements dissolved in water and minerals that you can hold in your hand,” said Michael Hochella Jr., University Distinguished Professor of geosciences at Virginia Tech. “The nanoscale represents a transition zone. For instance, the electronic, magnetic, and optical properties at the atomic, nano, and bulk scales are all different.”

The cover story of the December issue of the Royal Society of Chemistry’s Journal of Environmental Monitoring (www.rsc.org/Publishing/Journals/em/) offers a critical review of the emerging field of “Aquatic environmental nanoparticles.” Written by Virginia Tech Ph.D. students Nicholas S. Wigginton of Holt, Mich., and Kelly (Plathe) Haus of Rochester, Minn., and Hochella, the article looks at recent advances in identifying nanoparticles in water and in understanding their properties and reactivity.

The review considers nanoparticles formed by natural processes in water and as unintended consequences of human activity, such as mining or water treatment.

“Because iron is the most abundant transition metal on Earth, and oxygen is the most abundant element in the crust, iron oxides are found in virtually all natural water and soil systems across a wide spectrum of pH, salinity, and geologic settings,” wrote Wigginton. Over billions of years, nature produced iron-oxide nanoparticles that carry elements and compounds great distances in rivers and groundwater, and that are also involved in catalysis and organic transformation. “And these nanoparticles account for a disproportionately large amount of potentially reactive surface area in the environment. As a result, what was once considered to exist in the dissolved fraction of water can no longer be viewed as such,” he said.

Meanwhile, humans are changing the natural nanoparticle distribution with no idea of the consequences. For instance, attempted cleanups can mobilize contamination release downstream or within a contamination plume through nanoparticle transport. And because contaminants are bound to nanoparticles, stability and interaction of contaminants are different than what was once predicted.

Even noninvasive clean-up is problematic, the review reports. Bioremediation of soluble uranium by microorganisms, such as metal-reducing bacteria, is of high interest. But a field study showed a large fraction of unreduced uranium after such an attempt. “The complexities behind the fate of metal and radionuclide contaminants during nanoparticle formation make predicting the final products very difficult,” said Wigginton, who has worked on this question at Pacific Northwest National Laboratory.

And the tools that make the study of nanoparticles possible, which include the scanning tunneling microscope, transmission electron microscope (TEM), atomic force microscope, are not part of any field kit.

The article relates two cases from the authors’ published and yet to be published research.

Due to almost 150 years of copper and silver mining and smelting activities, the Clark Fork River has been contaminated with high levels of toxic metals including arsenic, lead, zinc, and copper. More than 100 million tons of mine waste has been introduced directly into the river and surrounding floodplains.

Toxic metal location, distribution, and transport in the Clark Fork River, the largest EPA Super Fund clean-up site in the U.S., has been Hochella’s research for many years. Transport of heavy metals is now the subject of Kelly Haus’ Ph.D. thesis. Despite remediation, elevated levels of metals occur more than 300 miles downstream from the mining source. Hochella’s group has sampled the riverbed and floodplain sediments and extensively studied them using TEM, discovering toxic heavy metals as structural components of several nanocrystalline phases. Hochella and Haus have also identified metal-bearing nanoparticles in water samples from the river.

“In Montana, we are finding that nanoparticles are important in transporting toxic heavy metals, such as lead and arsenic, down the river,” said Hochella. “These particles are incredibly small – 5 to 10 nanometers. Historically, we have not even known the nanoparticles were there. Now we know that lead in solution is different than if it is attached to a particle. But finding the particles is not easy. And impact on bioavailability is still unknown.”

He asks, “Are the metals less toxic if they are associated with nanoparticles than if dissolved as atoms in water? If a person, animal, fish, or insect ingests this water, will lead pass harmlessly through if it is associated with a nanoparticle?

“What Kelly learns about the role of nanoparticles in metal transport will be applicable to rivers worldwide,” Hochella said.

Closer to home, the authors asked, can environmental nanoparticles, which both transport and break down contaminants, affect the quality of our drinking water – despite or because of water treatment processes?

As a model system for identifying the mineral phase(s) of nanoparticles extracted from treated waters, Virginia Tech researchers examined tap water from Washington, D.C., which had had a significant problem with dangerously high lead concentrations in drinking water, likely due to leaching from lead-bearing pipes promoted by breakdown products of disinfection agents, according to Marc Edwards, professor of civil engineering at Virginia Tech, who was named a MacArthur Fellow for his work. The Virginia Tech geosciences group’s TEM data showed the presence of many nanoparticles of various compositions, sizes, and morphologies, some of which contain lead.

Wigginton wrote, “Although very few studies have been done to address the origin of nanoparticles in drinking water systems, it is relatively safe to assume one of three mechanisms: 1) the particles themselves (not necessarily the sorbed species that they are carrying) are native to the source water and are resilient enough to withstand chemical processing steps at the treatment facility; 2) nanoparticulate phases precipitate once inside the treatment plant and/or distribution system in response to changing chemical conditions; or 3) corrosion of pipes promoted by disinfectants and/or their degradation byproducts could cause nanoparticles attached to the piping material to detach.” He said that preliminary evidence suggests lead transport is influenced by environmental nanoparticles from the source water that have made it through the treatment facility and into the distribution system.

The researchers concluded that “environmental nanoparticle science will have to advance aggressively along at least two research paths: 1) fundamental research on the physical property and chemical reactivity variability of nanoparticles as a function of their size; and 2) the detailed study and understanding of the influence of nanoparticles on aqueous chemical processes.”

Hochella observed that the Journal of Environmental Monitoring prefers to give engineers and scientists information about processes, “but we are not yet able to tell engineers and scientists in the field where the nanoparticles and metals are and why nanoparticles behave differently. But it certainly is important that they know that recent research is calling assumptions about transport, remediation, and water treatment into question.”

The review concludes that “nanoparticle science goes well beyond the traditional boundaries of aqueous colloid science, but clearly these fields are highly complementary and are already beginning to merge.”


###
Hochella is a pioneer in the field of nano-bio-geochemistry. Learn more about his group at http://www.geochem.geos.vt.edu/hochella/

Wigginton, who studies microbe-mineral interaction, was one of the U.S. Ph.D. students selected to visit with Nobel Laureates last year. Haus is an National Science Foundation Integrative Graduate Research and Education Traineeship (IGERT) Fellow.
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PostPosted: Tue Dec 04, 2007 2:55 pm    Post subject: Technique controls nanoparticle size, creates large numbers Reply with quote

Technique controls nanoparticle size, creates large numbers

Scaling up the small business

By Erin Fults


Dec. 3, 2007 -- In a world that constantly strives for bigger and bigger things, Washington University in St. Louis' Pratim Biswas, Ph.D., the Stifel and Quinette Jens Professor and chair of the Department of Energy, Environmental and Chemical Engineering, is working to make things smaller and smaller.

Biswas conducts research on nanoparticles, which are the building blocks for nanotechnology. For the first time, Biswas has shown that he can independently control the size of the nanoparticles that he makes while keeping their other properties the same. He's also shown with his technique that the nanoparticles can be made in large quantities in scalable systems, opening up the possibility for more applications and different techniques.

Nanotechnology has far-reaching applications in microelectronics, renewable energy and medicine, just to name a few. But the first step is synthesizing and understanding nanoparticles.

To put the size of a nanoparticle into perspective, compare it to a human hair. One strand of human hair is about 50 to 100 micrometers thick. One nanometer is 1/1000 of a micrometer. A nanoparticle is 100 nanometers thick.

"It's difficult to imagine dividing a meter up into a million pieces and then a nanometer is a thousandth of that," explained Biswas. "These are very tiny particles."

This small size is critical in the applications. By varying the size, nanoparticles can efficiently be tuned to perform a specific task, be it cosmetics or pollution clean up.

"When I reduce the size of the object, then the properties are very different. They can have certain unique properties," said Biswas. "By changing the size and the crystal structure you can tune the functionality."


Fabulous Flames

To make these nanoparticles and to alter their size, Biswas uses a flame aerosol reactor (FLAR). The flame provides a high-temperature environment in which molecules can be assembled in a single step.

Biswas described the technique and his work in a recent issue of Nanotechnology.

"Bring the material in, react it, form the particles and then collect it and go and use it," said Biswas.

This technique also allows for mass production, once the conditions to produce the desired material have been determined.

Controlling the size of these particles is what opens doors to new and unique uses.

"The applications are plentiful," said Biswas. "The other thing is, if I can make materials of very narrow sizes, I can study the properties as a function of size — which has not been possible in the past — with very precise controls so we can do fundamental research. And that allows me to come up with new applications."


Dig those crazy tires

Such new applications may even change the way we think about driving. Tired of boring, black car tires? With nanotechnology, tires could become a fashion statement with red, pink, blue, green, or "any color you want" as possibilities.

"All tires are black in color because of the carbon that is added. Which color you want is not important, because now you could add a silica-based material which will allow you to get any color of your choice," said Biswas. "Nanoparticles are going to be used everywhere. They are already being used in many applications — cosmetics, microelectronics — but now you are going to use it for tires."

With all of these new applications come budding new fields of study. One area is nanotoxicology, which researches the health and environmental safety of new materials containing nanoparticles. Nanotechnologists join forces with biologists to determine the safety of different-sized particles. For example, one size particle may provide the best effects in a cosmetic, but manufacturers must make sure that it shouldn't cause toxic effects in a person's body.

"We don't want to just release it to the environment. The general feeling is that you have to be proactive, make sure everything is OK and then go, so here you are trying to be as cautious as possible," said Biswas.

Biswas' work focuses mainly on making the nanoparticles, but his research has led to a variety of applications and collaborations. Biswas is currently collaborating with Sam Achilefu, Ph.D., associate professor of radiology in the Washington University School of Medicine. Achilefu is working to selectively deposit imaging agents. Rather than flood a cancer patient's body with a drug during chemotherapy, for example, nanotechnology and selective deposits could deliver and concentrate the drug in the region of the tumor.

"These are very preliminary," said Biswas, "but we're getting some neat results. So there are some cautious examples, like toxicology, but then there are many useful applications."

Biswas also stresses the importance in the global marketplace. Nanotechnology has the potential to purify drinking water for rural populations worldwide. Such efforts send a "big social message," said Biswas. Renewable energy is yet another possible application of nanotechnology.

The possibilities of nanotechnology are endless, and everyday Biswas embarks on this exciting journey.

"That's the beauty here. At Washington University we have a very strong aerosol science and technology group. I would say one of the strongest in this area," said Biswas. "Furthermore, there are many collaborators in different disciplines where we can explore new application areas. So our ability to make tailor-made nanoparticles with very tight control of properties will allow more applications to be invented. That's the driving force — the ability to synthesize nanoparticles. They are the building blocks of nanotechnology."
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PostPosted: Fri Dec 07, 2007 2:44 pm    Post subject: Nanotube-producing bacteria show manufacturing promise Reply with quote

University of California - Riverside
7 December 2007

Nanotube-producing bacteria show manufacturing promise
Nanotubes may have high-tech applications, study involving UCR engineers reports

RIVERSIDE, Calif. – Two engineers at the University of California, Riverside are part of a binational team that has found semiconducting nanotubes produced by living bacteria – a discovery that could help in the creation of a new generation of nanoelectronic devices.

The research team believes this is the first time nanotubes have been shown to be produced by biological rather than chemical means. It opens the door to the possibility of cheaper and more environmentally friendly manufacture of electronic materials.

Study results appear in today's issue of the early edition of the Proceedings of the National Academy of Sciences.

The team, including Nosang V. Myung, associate professor of chemical and environmental engineering in the Bourns College of Engineering, and his postdoctoral researcher Bongyoung Yoo, found the bacterium Shewanella facilitates the formation of arsenic-sulfide nanotubes that have unique physical and chemical properties not produced by chemical agents.

“We have shown that a jar with a bug in it can create potentially useful nanostructures,” Myung said. “Nanotubes are of particular interest in materials science because the useful properties of a substance can be finely tuned according to the diameter and the thickness of the tubes.”

The whole realm of electronic devices which power our world, from computers to solar cells, today depend on chemical manufacturing processes which use tremendous energy, and leave behind toxic metals and chemicals. Myung said a growing movement in science and engineering is looking for ways to produce semiconductors in more ecologically friendly ways.

Two members of the research team, Hor Gil Hur and Ji-Hoon Lee from Gwangju Institute of Science and Technology (GIST), Korea, first discovered something unexpected happening when they attempted to remediate arsenic contamination using the metal-reducing bacterium Shewanella. Myung, who specializes in electro-chemical material synthesis and device fabrication, was able to characterize the resulting nano-material.

The photoactive arsenic-sulfide nanotubes produced by the bacteria behave as metals with electrical and photoconductive properties. The researchers report that these properties may also provide novel functionality for the next generation of semiconductors in nano- and opto-electronic devices.

In a process that is not yet fully understood, the Shewanella bacterium secretes polysacarides that seem to produce the template for the arsenic sulfide nanotubes, Myung explained. The practical significance of this technique would be much greater if a bacterial species were identified that could produce nanotubes of cadmium sulfide or other superior semiconductor materials, he added.

“This is just a first step that points the way to future investigation,” he said. “Each species of Shewanella might have individual implications for manufacturing properties.”


###
Myung, Yoo, Hur and Lee were joined in the research by Min-Gyu Kim, Pohang Accelerator Laboratory, Pohang, Korea; Jongsun Maeng and Takhee Lee, GIST; Alice C. Dohnalkova and James K. Fredrickson, Pacific Northwest National Laboratory, Richland, Wash.; and Michael J. Sadowsky, University of Minnesota.

The Center for Nanoscale Innovation for Defense provided funding for Myung’s contribution to the study.

The University of California, Riverside is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment of about 17,000 is projected to grow to 21,000 students by 2010. The campus is planning a medical school and already has reached the heart of the Coachella Valley by way of the UCR Palm Desert Graduate Center. With an annual statewide economic impact of nearly $1 billion, UCR is actively shaping the region's future. To learn more, visit www.ucr.edu or call (951) UCR-NEWS.
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PostPosted: Mon Dec 10, 2007 1:53 pm    Post subject: “Golden bullet” shows promise for killing common parasite Reply with quote

“Golden bullet” shows promise for killing common parasite
10 December 2007
Nano Letters

Researchers in Australia report development of a new type of gold nanoparticle that destroys the parasite responsible for toxoplasmosis, a potentially serious disease acquired by handling the feces of infected cats or eating undercooked meat. Their so-called “golden bullet” could provide a safer, more effective alternative for treating the disease than conventional drug therapy, they say. The study is scheduled for the Dec. issue of ACS’ Nano Letters, a monthly journal.

Toxoplasma gondii, the parasite that causes the disease, infects more than 60 million people in the United States alone. Although most infected people have no symptoms, it can cause serious health problems in pregnant women and individuals such as AIDS patients or organ transplant recipients who have weakened immune systems.

In the new study, Michael Cortie and colleagues attached antibodies to the parasite onto gold nanorods that are activated by laser-light. A group of Toxoplasma-infected animal cells were isolated in cell culture dishes and subsequently exposed to these “golden bullets.” The cells were then exposed to laser-light, which heated up the “bullets” and destroyed the parasites. The treatment killed about 83 percent of the parasites containing the gold particles, the researchers say. They hope to develop a similar technique for killing the parasite in patients.

ARTICLE #1 FOR IMMEDIATE RELEASE
“A Golden Bullet" Selective Targeting of Toxoplasma gondii Tachyzoites Using Antibody-Functionalized Gold Nanorods”

DOWNLOAD PDF http://pubs.acs.org/cgi-bin/sa.....72377+.pdf
DOWNLOAD HTML http://pubs.acs.org/cgi-bin/sa.....2377+.html
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PostPosted: Wed Dec 19, 2007 6:54 pm    Post subject: Stanford's nanowire battery holds 10 times the charge of exi Reply with quote

Stanford Report, December 18, 2007
Stanford's nanowire battery holds 10 times the charge of existing ones

BY DAN STOBER

Stanford researchers have found a way to use silicon nanowires to reinvent the rechargeable lithium-ion batteries that power laptops, iPods, video cameras, cell phones, and countless other devices.

The new version, developed through research led by Yi Cui, assistant professor of materials science and engineering, produces 10 times the amount of electricity of existing lithium-ion, known as Li-ion, batteries. A laptop that now runs on battery for two hours could operate for 20 hours, a boon to ocean-hopping business travelers.

"It's not a small improvement," Cui said. "It's a revolutionary development."

The breakthrough is described in a paper, "High-performance lithium battery anodes using silicon nanowires," published online Dec. 16 in Nature Nanotechnology, written by Cui, his graduate chemistry student Candace Chan and five others.

The greatly expanded storage capacity could make Li-ion batteries attractive to electric car manufacturers. Cui suggested that they could also be used in homes or offices to store electricity generated by rooftop solar panels.

"Given the mature infrastructure behind silicon, this new technology can be pushed to real life quickly," Cui said.

The electrical storage capacity of a Li-ion battery is limited by how much lithium can be held in the battery's anode, which is typically made of carbon. Silicon has a much higher capacity than carbon, but also has a drawback.

Silicon placed in a battery swells as it absorbs positively charged lithium atoms during charging, then shrinks during use (i.e., when playing your iPod) as the lithium is drawn out of the silicon. This expand/shrink cycle typically causes the silicon (often in the form of particles or a thin film) to pulverize, degrading the performance of the battery.

Cui's battery gets around this problem with nanotechnology. The lithium is stored in a forest of tiny silicon nanowires, each with a diameter one-thousandth the thickness of a sheet of paper. The nanowires inflate four times their normal size as they soak up lithium. But, unlike other silicon shapes, they do not fracture.

Research on silicon in batteries began three decades ago. Chan explained: "The people kind of gave up on it because the capacity wasn't high enough and the cycle life wasn't good enough. And it was just because of the shape they were using. It was just too big, and they couldn't undergo the volume changes."

Then, along came silicon nanowires. "We just kind of put them together," Chan said.

For their experiments, Chan grew the nanowires on a stainless steel substrate, providing an excellent electrical connection. "It was a fantastic moment when Candace told me it was working," Cui said.

Cui said that a patent application has been filed. He is considering formation of a company or an agreement with a battery manufacturer. Manufacturing the nanowire batteries would require "one or two different steps, but the process can certainly be scaled up," he added. "It's a well understood process."

Also contributing to the paper in Nature Nanotechnology were Halin Peng and Robert A. Huggins of Materials Science and Engineering at Stanford, Gao Liu of Lawrence Berkeley National Laboratory, and Kevin McIlwrath and Xiao Feng Zhang of the electron microscope division of Hitachi High Technologies in Pleasanton, Calif.
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PostPosted: Mon Jan 14, 2008 1:56 pm    Post subject: Tiny Magnets to Attack Disease at Cellular Level Reply with quote

Tiny Magnets to Attack Disease at Cellular Level
By Clara Moskowitz, LiveScience Staff Writer

posted: 14 January 2008 09:20 am ET

By injecting tiny magnets into your body, doctors hope to treat diseases without using chemicals or hormones. Don't worry about sticking to the refrigerator — the nano-sized magnets are only strong enough to affect your cells.

For the first time, doctors created bead-shaped magnets that bind with receptor molecules on cell walls. When a magnetic field is applied, the beads are attracted to each other and pull together, dragging the receptors with them. As they cluster, the receptors release biochemical signals that trigger cell functions.


For the full article:

http://www.livescience.com/080.....ntrol.html
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PostPosted: Mon Jul 28, 2008 9:55 am    Post subject: Toward designer bourbon whiskeys with custom-tailored aromas Reply with quote

Toward designer bourbon whiskeys with custom-tailored aromas

Journal of Agricultural and Food Chemistry
28 July 2008

In the latest chapter in a 40-year scientific quest to unravel the flavor and aroma secrets of the world's whiskeys, scientists in Germany are reporting discovery of key substances responsible for the distinctive bouquet of American bourbon whiskey. The study, which aims to help improve bourbon through a better understanding of its individual components, is scheduled for the July 23 issue of ACS' bi-weekly Journal of Agricultural and Food Chemistry.

Peter Schieberle and Luigi Poisson point out that more than 300 compounds have been identified over the years in whiskey. However, only a few studies have focused on the key aroma compounds, which are most responsible for the fruity, smoky, vanilla and other harmonics of whiskey.

In the study, Schieberle and Poisson analyzed more than 40 of Bourbon's compounds — 13 of them newly discovered — that blend to create its rich profile, a signature mixture of scents, including fruity, earthy and cooked apple. The new information could be useful in changing the recipe or manufacturing processes for bourbon in order to produce whiskey with distinctive flavors, they note. — JS

ARTICLE #2 FOR IMMEDIATE RELEASE
"Characterization of the Most Odor-Active Compounds in an American Bourbon Whisky by Application of the Aroma Extract Dilution Analysis"

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http://dx.doi.org/10.1021/jf800382m
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PostPosted: Mon Aug 11, 2008 1:06 pm    Post subject: Scientists develop the world's thinnest balloon Reply with quote

Scientists develop the world's thinnest balloon
11 August 2008
Nano Letters

Researchers in New York are reporting development of the world's thinnest balloon, made of a single layer of graphite just one atom thick. This so-called graphene sealed microchamber is impermeable to even the tiniest airborne molecules, including helium. It has a range of applications in sensors, filters, and imaging of materials at the atomic level, they say in a study scheduled for the August 13 issue of ACS' Nano Letters, a monthly journal.

Paul L. McEuen and colleagues note that membranes are fundamental components of a wide variety of physical, chemical and biological systems, found in everything from cellular compartments to mechanical pressure sensing. Graphene, a single layer of graphite, is the upper limit: A chemically stable and electrically conducting membrane just one atom thick. The researchers wanted to answer whether such an atomic membrane would be impermeable to gas molecules and easily incorporated into other devices.

Their data showed that graphene membranes were impermeable to even the smallest gas molecules. These results show that single atomic sheets can be integrated with microfabricated structures to create a new class of atomic scale membrane-based devices. We envision many applications for these graphene sealed microchambers, says McEuen. These range from hyper-sensitive pressure, light and chemical sensors to filters able to produce ultrapure solutions.

ARTICLE #1 FOR IMMEDIATE RELEASE
"Impermeable Atomic membranes from Graphene Sheets"

DOWNLOAD FULL TEXT ARTICLE
http://dx.doi.org/10.1021/nl801457b
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PostPosted: Mon Dec 15, 2008 12:59 pm    Post subject: Reply with quote

Vibration-Rotation Spectroscopy of Molecules trapped inside C60
Max Moskowitz

Life on earth is composed primarily of carbon-based chemicals. From the substances of our bodies and the materials of our modern world to the crises threatening our species as a whole, it touches every aspect of our lives. Plastics and rubbers as well as fossil fuels and greenhouses gases all owe their existence to the fundamental nature of carbon and the myriad of structures it can form. It is, therefore, vital to our survival and development to understand carbon in all of its many forms.

When people not initiated into the chemical community think of pure carbon, they imagine the graphite in their mechanical pencils or the diamonds adorning their jewelry. However, there is a third allotrope of carbon that has started making its way into the mainstream media. Buckminster fullerenes (1) or buckyballs as they have been dubbed have presented chemists with entirely new avenues to pursue as well as fresh perspectives upon old ideas. Unlike the molecular lattices that make up graphite and diamond, buckyballs are distinct molecules. Each individual molecule is composed of sixty carbons arranged in the shape of a soccer ball with the carbon atoms occupying the sixty vertices. It is this unique structure that gives rise to so many potential applications. The C60 molecule contains a hollow interior which can encapsulate some other molecular species. This property can be used for storage purposes as well as transportation. Unlike other capsule molecules, buckyballs are composed of fully covalent bonds rather than noncovalent bonds that can be easily disrupted. The buckyball can be used to store hydrogen gas for use in fuel cells. (2) Alternatively, it can be used to transport radioactive metals to help in MRI imaging. (3) In order to develop such technologies, it is necessary to study the effects of encapsulating these molecules within the C60 cage. Unfortunately, when dealing with individual molecules, we cannot study them with the naked eye and even the microscope fails to obtain a picture of the inner workings of these materials. In order to understand the effect of encapsulating a molecule inside a C60 cage, we have to turn to a field known as Spectroscopy.

Spectroscopy allows us to obtain a picture of what is happening at the molecular level. Like our eyes and the microscope, spectroscopy makes use of the way light interacts with matter to gain an insight into the structure and motion of a thing. However, spectroscopy is more specific in the type of interaction and the nature of the information obtained. The form of spectroscopy most useful to us in the study of buckyball encapsulated molecules is known as vibrational spectroscopy. In this type of spectroscopy we are probing the molecule for information about the nature of its internal motions. Each molecular bond can be pictured as a pair of masses attached to each other by a spring of a certain strength. These “springs” vibrate at characteristic frequencies that are representative of the interacting atoms and their relative environments. In addition to these vibrations, the bonded atoms are rotating, also at characteristic frequencies. Complicating matters, these different types of motion can couple to each other. The spectroscopic experiment uses light in the infrared part of the spectrum to capture these different motions by obtaining their characteristic frequencies. These frequencies can then be used to find the rotations and vibrations of the molecules in question.

Two methods are open to the chemist when studying the vibrational spectra of a molecule. A spectra can be experimentally obtained or the molecule can be mathematically modeled and the spectra can be theoretically determined. While the first method will usually give more accurate vibrational spectra, the use of molecular modeling will give insights into the molecule that could not have been obtained otherwise. This information can then help in unraveling the experimental spectrum and assigning frequencies to molecular motions. Given the amount of calculations that are required in order to precisely model a molecule, some assumptions are made in order to make these calculations more manageable. It is these assumptions that will cause the deviation between the calculated and the experimental spectra. However at the same time, it is these assumptions that will give insight into the structure and motions of the molecule.

A simple example of a molecule encapsulated in a buckyball is the endohedral fullerene C60@CO. (4) This is the molecule carbon monoxide trapped in a buckyball. Spectroscopic studies of the free molecule CO are well-known so that comparisons can be made with the spectrum of the trapped CO. In order to simplify calculation of the trapped CO, it was assumed that the interior of the buckyball was spherically symmetrical rather than the actual icosohedral symmetry. Practically, this means that regardless of how the molecule is oriented inside the C60 cage, there is no change in potential energy. This allows us to treat the system as a molecule trapped in a spherical cage with only six degrees of motional freedom. The molecular motion is then reduced to describing the vibration and rotation of the molecule and its ”rattling” movement inside the cage. The results of the experiment show that the spectrum of C60@CO is approximately equal to that of the gas phase spectrum of the free CO molecule at the low temperature of 20K. If the same experiment is run at 300K, the spectrum approaches that of CO in solution. These results show that interaction of the CO molecule with the C60 cage is temperature dependent and more strongly felt at high temperatures. However because of the assumption of spherical symmetry, this model does not accurately represent all of the molecular motion. Certain motions that are degenerate or equal in energy under spherical symmetry are not equal in energy under icosahedral symmetry. Therefore, while we have a better understanding of the rotational and vibrational motions of a trapped diatomic molecule, it is neither totally accurate nor complete. (5)

The goal of these experiments is to better understand the interaction between a buckyball host, and its guest molecule. The use of spectroscopic methods allows an understanding of these molecular interactions leading to better methods of encapsulation as well as more applications for these novel species. Spectra can be obtained from both theory and experiment giving different insights into the same problem. These insights into the understanding of the motions of trapped species can then be extended to buckyball derivatives like carbon nanotubes and all of the technologies they are said to herald. (6) Carbon, in whatever form it can be found, will always play a significant role in our lives.

(1) Science 1991, 253, 1476-79
(2) Science 2005, 307, 238-240
(3) Indian J Pharm Sci 2006, 68, 13-9
(4) J. Org. Chem. 2003, 68, 8281-83
(5) J. Phys. Chem. A 2008, 112, 7152-56
(6) Science 2002, 297, 787-92

Further Readings

A) What are Buckyballs? - http://en.wikipedia.org/wiki/Fullerene

B) What are Nanotubes? - http://en.wikipedia.org/wiki/Carbon_nanotube

C) What is Spectroscopy? - http://en.wikipedia.org/wiki/Spectroscopy

D) What is Vibrational Spectroscopy? - http://en.wikipedia.org/wiki/V.....ectroscopy

E) What is Infrared (IR) Spectroscopy? - http://en.wikipedia.org/wiki/IR_spectroscopy
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PostPosted: Mon Dec 15, 2008 1:02 pm    Post subject: Reply with quote

Ashley Morris
December 15, 2008
Professor de Dios

Diameter Selection of Single-Walled Carbon Nanotubes through Programmable Solvation in Binary Sulfonic Acid Mixtures

Carbon nanotubes have become an increasing area of study over the last fifteen years as a result of their initial synthesis in the early 1990’s. Their growth in popularity developed into new nanotube research areas in industry fields for a practical development protocol. In particular, single walled nanotubes (SWNT) were not synthesized and studied intensely until 1993 by Iijima and Ichihashi (1); and since then research has expanded to include the numerous properties that enhance the viability of single-walled carbon nanotubes.

Nanotubes are highly sought after because of their electronic properties, strength and durability; they possess a broad depth of potential applications in electronic technology, material sciences and optics (2). The strength and durability of a carbon nanotube comes from the integration of the internal and external structures. Bonding within the internal structure is designed on a sp2 system which describes the hybridization of one carbon atom; the central carbon is surrounded by three adjoining neighbors lending to the structural components of the carbon nanotube. Structurally the single-walled carbon nanotubes are a cylinder of rolled graphene, which is a single layer of graphite (3); these cylinders’ continual stacking geometry can be visualized as a honey-comb hexagonal pattern where each hexagon interlocks to provide strength and stability to the nanotube. Because of the honey-comb pattern the nanotubes can be manipulated to fold into three distinct symmetries – zigzag, arm chair, and chiral, which is the most common folding applied to nanotube construction (4). Other crucial properties of the nanotubes include their electronic properties which are enhanced by the strong bonding and stabilization of a sp2 hybridization bonding system. Electronic properties that have enhanced the popularity of the SWNT include their propensity to be either a semiconductor or metallic, which is determined by the structural rolling of the nanotube itself during synthesis. Semiconducting properties allow nanotubes to be applied in the ever expanding technology market, while metallic nanotubes possess the ability to have higher electric current density than metals like copper and silver (5).

Nanotubes can be synthesized by arc discharge, laser ablation, or chemical vapor disposition methods; over the years methods have been tuned and catalysts added to make nanotube production more effective and efficient for the scientific community. During synthesis of SWNT, metals are often used as catalysts to help accelerate the process; however, by doing this the metals are hard to separate from the final product which ultimately alters the surface chemistry of the SWNT and potentially changing their electronic properties. With the sought after properties that carbon nanotubes possess for potential applications, it begs the need for easier methods to purify and separate the nanotubes after the syntheses steps.

Researchers at R.E. Smalley Institute for Nanoscale Science and Technology at Rice University have been focusing on a way to increase the purity of the nanotubes after they have been synthesized. Currently, during the purification step many of the metals, and even the solvents being used during the process, are being deposited and forming a molecular monolayer around the nanotubes. The monolayer acts as a barrier around the tube creating a filmy layer changing the surface chemistry of the newly synthesized nanotube. Some improvements have been made in the purification step but the improvements have not yet been advanced to the point where they are applicable to large scale syntheses of nanotubes. Another significant challenge is the loss of the delocalized electrons in the pi-system of the nanotube which possesses many of the sought after properties (6). The electrons in the pi-system are from the sp2 system that lends to the nanotubes’ strength and durability, which can be limited or even lost during the purification methods currently available. At present researchers are trying to develop a method to synthesize the “holy grail” (7) of carbon nanotube syntheses and technology, which includes making pure carbon nanotubes with an easy separation technique utilizing their physical properties and enhancing the way carbon nanotubes are individually dissolved.

Once the nanotubes are synthesized and mixed with varying molarities of chlorosulfonic acid during the purification step, they are studied by Raman spectroscopy to observe how the solvating power of the acid affects the properties of the SWNT by shifting the peaks normally observed in Raman Spectroscopy. Raman Spectroscopy is used to study the rotational, vibrational, and other low frequency components of a system and in the case of carbon nanotubes, by shining lasers on the sample producing a scattering of radiation of different wavelengths and of different intensities. The peaks correspond to a shift in the wavelength from the incident light by the energies that correspond to different molecular vibrations in the system when excited by lasers (Cool. The Raman active modes of the SWNT can be separated by their geometries zigzag, arm chair and chiral; and based on the apparent geometry the system gave corresponding peaks when tested in Raman Spectroscopy. The SWNT are divided based on their geometry and diameter of the tube; however, there are several diameters, so to be able to better separate and define the nanotubes radial breathing modes (RBM) were analyzed. Radial breathing modes are inversely proportional to the diameter of the nanotube; by analyzing the peak height for the diameter the nanotubes that are close in size were able to be separated (9). Once the nanotubes are classified based on their diameter, the Raman Spectroscopy output can be analyzed to determine the properties of the SWNT. Properties that can be inferred from the Raman output are metallic properties (metallic or semiconducting) and orientation of the nanotube sample including the angles within the nanotubes (10).

Additional analysis of the Raman output with correlation to the molarity of the chlorosulfonic acid used during the purification process of nanotube synthesis is a linear relationship, when the molarity of the acid increases in turn the diameter of the single-walled carbon nanotubes also increases. This linear relationship of diameter versus molarity indicates that the ability to tune the solvating power of the acid is there, and by selecting the appropriate molarity of chlorosulfonic acid (or another acid) certain properties of the nanotube can be rendered. By fine tuning the solvating chlorosulfonic acid, single-walled carbon nanotubes could be synthesized possessing only the electronic and physical properties that are imperative to the specific needs of a project; the length and size of the nanotube could be selected along with the preference of electric properties (semiconductor or metallic). The ability to fine tune nanotubes in particular single-walled carbon nanotubes allows for the growth and expansion in potential applications of nanotubes and the methods utilized during synthesis. Researchers believe that additional fine-tuning of the acid will pave the way to easier separation techniques of the nanotubes during the purification step and advance the possibilities of using single-walled carbon nanotubes in molecular chemistry specifically dealing with the interaction of the nanotubes with other molecules of a system leading to the application of the nanotubes in new technology.

References:
(1) "Single-shell carbon nanotubes of 1-nm diameter", S Iijima and T Ichihashi Nature, 363, 603 (1993) and "Cobalt-catalyzed growth of carbon nanotubes with single-atomic-layer walls", D S Bethune, C H Kiang, M S DeVries, G Gorman, R Savoy and R Beyers, Nature, 363, 605 (1993)

(2) Harris, Peter. "Carbon Nanotube Science and Technology." Nanotubes. 01 MAR 2007. University of Redding. 10 Dec 2008 <http>.

(3) et al

(4) Tomenak, David. The Nanotube Site. 11 Nov 2008. Michigan State University. 10 Dec 2008 <http>.

(5) et al

(6) Ramesh, Sivarajan, Hongwei Shan, Eric Haroz, W.E. Billups, Robert Hauge, W. Wade Adams, and Richard E. Smalley. "Diameter Selection of Single-Walled Carbon Nanotubes through Programmable Solvation in Binary Sulfonic Acid Mixtures." The Journal of Physical Chemistry C 111(4Cool, (2007) 17827-17834. 10 Dec 2008 <http>.

(7) et al

(Cool Anderson, Larry. "Raman Spectroscopy." 2000. Colorado University Denver. 12 Dec 2008 <http>.

(9) Ramesh, Sivarajan, Hongwei Shan, Eric Haroz, W.E. Billups, Robert Hauge, W. Wade Adams, and Richard E. Smalley. "Diameter Selection of Single-Walled Carbon Nanotubes through Programmable Solvation in Binary Sulfonic Acid Mixtures." The Journal of Physical Chemistry C 111(4Cool, (2007) 17827-17834. 10 Dec 2008 <http>.

(10) Fasoli, Andrea, Felipe Cervantes. "Nanotubes." Department of Engineering, University of Cambridge. Cambridge University. 13 Dec 2008 <http>.


Websites to further explore the topic:

What is Carbon?
http://www.chemicalelements.com/elements/c.html

What are Carbon Nanotubes?
http://en.wikipedia.org/wiki/C.....gle-walled

The Nanotube Site (everything about carbon nanotubes)
http://www.pa.msu.edu/cmp/csc/nanotube.html

How are carbon nanotubes synthesized?
http://en.wikipedia.org/wiki/Carbon_nanotube

What do carbon nanotubes look like? Carbon nanotube animation
http://www.photon.t.u-tokyo.ac.....otube.html

What are zigzag, arm chair and chiral folding?
http://www.personal.rdg.ac.uk/~scsharip/tubes.htm


Carbon Nanotube Properties and Applications:
What are semiconductors? (With a movie based explanation.)
http://museum.toshiba.co.jp/01.....on01.html#

Electronic properties
http://www.personal.rdg.ac.uk/~scsharip/tubes.htm

Applications of carbon nanotubes
http://www.azonano.com/details.asp?ArticleID=980

R.E. Smalley Institute for Nanoscale Science and Technology, Rice University
http://cnst.rice.edu/

What are lasers?
http://www.colorado.edu/physic.....index.html

What is Raman Spectroscopy?
http://carbon.cudenver.edu/pub...../raman.htm

http://en.wikipedia.org/wiki/Raman_spectroscopy

How are lasers used in Raman spectroscopy?
http://www.scienceofspectrosco.....ectroscopy

Raman Spectroscopy of carbon nanotubes
http://www-g.eng.cam.ac.uk/edm.....tubes.html

GAMES:
Gen-Nano game, compete as a scientist by completing the missions
http://www.generation-nano.org/index.php

Make your own Nanotube!
http://jcrystal.com/steffenweb.....jnano.html

What are semiconductors?
http://nobelprize.org/educatio.....onductors/
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