Posts Tagged ‘nanoparticles’
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June 30th, 2010
New memory devices
New flexible non-volatile organic memory devices have been developed on plastic substrates based on organic thin-film transistors embedded with self-assembled gold nanoparticles. The team working on this is led by Jang-Sik Lee, former Samsung researcher and now at Kookmin University in South Korea. This is really cutting-edge stuff and could open up a whole new area for gold in electronics. See Nano Letters for more details
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June 14th, 2010
Best of the web…….
A couple of gold science related stories catching the eye this morning:
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June 9th, 2010
Don’t break a leg….
Repetitive stress to bone tissue causes tiny cracks or scratches, known as microdamage, which increases the risk of fractures and can be a major concern for both the physically active and elderly. Yesterday, in discussion with Ryan Roeder at the University of Notre Dame, I became aware that scientists have demonstrated three-dimensional imaging of damaged bone tissue using functionalised gold nanoparticles. This work was published earlier this year. A really promising piece of research, let’s hope it is followed up with proof-of-concept and product development…. -
April 16th, 2010
Nanogold makes an appearance
The use of gold nanoparticles in high value cosmetics has been growing in recent years, although the scientifically proven benefits of this are not completely clear. Now, however, there appears to be a potential new use of gold nanoparticles relating to skin condition. According to the The Times of India the skin dwelling bacteria (Propionibacterium acnes) that cause common acne can be targeted using gold nanoparticles for drug-delivery.
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November 27th, 2009
L’Oreal award for gold work
Great to see another award going to researchers working on gold. This time it is to Dr Zarina Aspanut Universiti Malaya, Kuala Lumpur who has received one of three L’Oreal Malaysia For Women in Science National Fellowships for 2009. Each year, a jury panel chooses three recipients, who each receive RM20,000 as financial assistance to pursue their research work in Malaysia. The programme is jointly conducted with the Malaysian National Commission for Unesco and supported by the Academy of Sciences Malaysia and Higher Education Ministry.
Dr Aspanutf is looking at the fabrication and characterisation of embedded gold nanoparticles in silicon dioxide thin film for solar cell and sensor applications.
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November 12th, 2009
Another Thought Leader
Last month we highlighted AZoNano’s excellent Thought Leaders series. Here’s another one about the use of engineered membranes, including those using gold nanoparticles…..
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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 15th, 2009
Most-cited Energy and Fuels
I’ve just received news of the Top 20 most-cited articles published in Energy and Fuels during the last three years and the list includes ‘Chemical Fluid Deposition of Pt-Based Bimetallic Nanoparticles on Multiwalled Carbon Nanotubes for Direct Methanol Fuel Cell Application’ *. This paper describes how bimetallic formulations including platinum-gold display an efficiency to oxidize methanol to carbon dioxide at least 60% better than the monometallic Pt nanoparticle catalysts reported previously.
* Energy Fuels, 2007, 21 (4), pp 2268–2271
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September 23rd, 2009
Lead-free packaging with gold inks?
This open access paper published in the Journal of Electronic Materials investigated gold nanoparticle inks as potential candidates for lead-free packaging applications. The main advantage of the inks are the very low melting points, good conductivity compared to eutectic solders and excellent thermal stability/electromigration resistance. -
September 21st, 2009
The use of gold for fabrication of nanowire structures
A few weeks ago I mentioned IBM were growing silicon nanowires using gold nanoparticles. An excellent review of why gold is by far the most widely used seed particle material for growth of semiconductor nanowires has just been published by a team from Lund University (Maria E Messing, Karla Hillerich, Jonas Johansson, Knut Deppert and Kimberly A Dick) in Gold Bulletin.
The review explains that although a couple of other materials have been reported to successfully initiate growth of nanowires, gold is the most universal particle material, capable of seeding a variety of different types of nanowires at a wide range of growth conditions. In the review the group identified and described the production and deposition methods of different types of gold particles used for nanowire growth including:
gold particles made from thin films
aerosol-generated gold particles
gold particles made by lithographic methods
and colloidal gold particles.
They also discussed the different advantages and disadvantages of each particle type if the nanowires are to be used for large scale production of semiconductor devices and perhaps most importantly, the fundamental reason for gold being superior to other materials for initiating growth of nanowires. Their conclusion? The ability of gold to easily form alloys with the growth precursors, its inertness to oxygen and the high diffusivities through gold are all important and added together are what make gold such a suitable material for nanowire seed particles.
Schematic demonstrating particle-assisted nanowire growth. (a) The seed particles are formed/deposited on the substrate and (b) by heating the substrate to a desired temperature and introducing growth materials an alloy is formed. (c) When a supersaturation of the alloy particle with growth material is achieved, nucleation occurs at the particle-substrate interface. (d) Nanowire growth occurs at the particle-wire interface as long as growth material is provided. (e) By switching to growth conditions favoring planar growth radial heterostructures, known as core-shell nanowires, can be grown. (f) Nanowires containing axial heterostructures with very sharp interfaces can be formed by switching between different growth materials. (g) If a second generation of gold particles is deposited onto the as-grown nanowires and (h) the growth process is repeated, branched nanowires for formation of nanowire networks can be grown.Copyright: Gold Bulletin
Richard Holliday
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