Archive for October, 2009
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October 30th, 2009
Enabling the next generation of high speed data networks
I was fascinated by this paper which recently appeared in Nanotechnology. My knowledge about the specifics of the field is limited, but the concept really grabs the imagination.
To understand the basics requires some of that (long-forgotten in my case) physics know-how you may have gleaned many years ago at school. Transfer of data via electromagnetic waves plays a part in practically every area of life nowadays and at its heart lies a key physical principle – communication between the transmitter and receiver of a data-containing wave reaches highest efficiency when the total length of the dipole antennas corresponds to about half of the wavelength of the electromagnetic wave. So, what is happening when you flick your radio on in the morning? Radio waves occupy the long wavelength, low frequency portion of the electromagnetic spectrum. FM radio waves have a wavelength in the region of 1m – 10m, so a bit of tinkering around with the long metal aeriel sticking out of the radio usually lets you find your favourite station. It’s often not a perfect reception, but the ‘data’ you are receiving is pretty minimal it doesn’t matter too much.
So, what happens when you start wanting more data, and quicker? Obviously the frequency of the wave has to go up, which means the wavelength begins to decrease. Now we start to hit difficulties. Remember if you want to receive this data efficiently, your antenna needs to be roughly half the wavelength… To put this in perspective, the wavelength of visible light is 400 – 700 nm, meaning your antenna needs to be no longer than 350 nm in length if you are receiving data from such a source. Ouch.This paper describes a method of reproducibly constructing such minute antenae from gold using an electron beam process called electron beam lithography. As I mentioned above my knowledge of the subject begins to waiver when you get into the fine details, but the authors believe this may be a significant breakthrough to aid the next generation of high-speed data networks.
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October 29th, 2009
Nanoscale hits the shelves
The Royal Society of Chemistry has further strengthened its list of publications with a new peer reviewed journal focusing on experimental and theoretical work across the breadth of nanoscience and nanotechnology. The first issue of Nanoscale is now available, and boasts 3 excellent gold-nanoparticle related papers from the groups of Vince Rotello, Moreno Meneghetti and Naomi Halas.The journal is available free in 2009-2010 by registering your details here.
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October 28th, 2009
Using plasmons to study gold catalysts
Some nice work described here on Physics World, using plasmons to study gold catalyst activity…..
UPDATE – Oops! Its just been pointed out that although gold was used in the experimental technique the catalyst was actually platinum.
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October 27th, 2009
Ford Motor Company and Au Nanoclad™
Some weeks ago I posted on the subject of fuel cell separator plates and how gold-coated stainless steel was proven to be the best material for this application, in terms of conductivity and durability. The only issue was cost – what was need was a reduced thickness gold coating, still displaying the performance of a thicker coating.
Well, according to a presentation to be made at Fuel Cells Durability & Performance 2009 (December 8-9, 2009 · Alexandria, VA USA) The Ford Motor Company is to present on ”Nanometer Range Gold Coated Stainless Steel for Automotive Polymer Electrolyte Membrane Fuel Cell Bipolar Plate”.
Apparently, Ford is currently developing metallic bipolar plate technology with thin gold-coated stainless steel (under the brand name Au Nanoclad™) provided by Daido Steel. They claim that the use of nanometer range gold coating delivers the required electrical conductivity and corrosion resistance with least impact of cost of gold. Additionally, gold-coated stainless steel shows anodic passivation, thereby exhibiting robustness towards coating defects including surface scratches during the manufacturing of the bipolar plate. Apparently the presentation at the conference will include the ex-situ and in-situ testing data for this material.Looks like a potentially fantastic new use for gold if the fuel cell market takes off…..
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October 26th, 2009
Gold nanoparticles research secures Gates Foundation grant
Scientists from Vanderbilt University in Nashville, Tennessee, have secured a $100,000 grant from the Bill & Melinda Gates Foundation to develop a technique that employs gold nanoparticles to diagnose malaria. Their project is one of 76 grants announced by the Gates Foundation in the third funding round of Grand Challenges Explorations, an initiative to help scientists around the world explore bold and largely unproven ways to improve health in developing countries. See the official press release here.
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October 23rd, 2009
New Gold Solar-Reflective Window Coatings?
‘Gold’ in this story could just relate to the colour rather than the metal itself but, although it doesn’t say it specifically, I suspect this might actually be a new market niche for gold. The story says:Gold aircraft window coatings by PPG Industries’ aerospace transparencies group are being introduced at the National Business Aviation Association (NBAA) annual meeting and convention offer aircraft manufacturers aesthetic choices in solar-reflective coating technology. PPG’s solar-reflective coatings for glass and plastic aircraft windows reduce the amount of infrared energy entering the cockpit and cabin for cooler temperatures and reduced air-conditioning load.
Gold’s role in glazing applications has been known for a long time (see this Gold Bulletin paper here). I imagine this technology maybe based on the application of gold nanoparticles – as highlighted in this other Gold Bulletin paper- rather than the more traditional sputtered coatings.
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October 22nd, 2009
AZoNano’s Thought Leaders
I recently highlighted AZoNano’s excellent series ‘Thought Leaders’. Another in this series again deals with gold; explaining how a nickel steam reforming catalyst can be improved though gold alloying additions and a potential way to improve the stability of gold catalysts on titania supports. Its definitely worth keeping an eye on this series – good quality stuff!
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October 21st, 2009
The world’s smallest test tube…?
I love reading about new nanotechnology breakthroughs, and the journal science is often a good place to look for such articles. Indeed there’s a great paper in the most recent issue penned by a team at the University of Texas at Austin. What the group, led by Brian Korgel, have done is fashion a nanoscale test tube out of a ultra-thin carbon shell. This nano test tube contains a gold nanocrystal on the end of a germanium nanowire.
Whilst this is a pretty unusual experimental set up, no question, it has allowed the team to closely study physical transformations in materials. Because the gold and germanium are both confined by the carbon shell, changes in volume and interfacial area are prevented on heating and cooling. Using electron microscopy, the fundamental heating, cooling and crystallisation processes of the gold and germanium could be observed – they even made a couple of movies of the melt/diffusion events!
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October 20th, 2009
Nanosphere news
Nanosphere, the nanotechnology-based healthcare company, has just released this press release announcing it has received 501(k) clearance from the US Food & Drug Administration for its influenza A & B and Respiratory Syncytial Virus (RSV) test and the Verigene SP System, with complete sample-to-result automation. This is an important milestone, as it allows patients access to the patented gold nanoparticle-based technology for influenza diagnosis in time for the coming flu season.
In a second piece of positive news for the company, a study has shown that the company’s gold-based technology has detected a protein specific to prostate cancer in 86 percent of blood samples compared with 25 percent for conventional tests. This data has been published in the Proceedings of the National Academy of Sciences, and has received widespread media coverage (for example see here for a thorough Bloomberg article).
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October 19th, 2009
Lisa and gold
Credit: NASA
It’s amazing the range of uses they find for gold….. LISA, the Laser Interferometer Space Antenna, is a joint NASA–ESA mission to observe astrophysical and cosmological sources of gravitational waves. LISA detects gravitational waves by measuring the change in separation between freely floating test masses. The test masses are gold-platinum alloy cubes; they weigh 2 kg, and have sides of 4.6 cm. Under drag-free operation, the test masses fall freely in space, and provide reference points for the LISA separation measurements. Read more here……
Trevor Keel
Richard Holliday
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