Archive for the ‘Nanoparticles’ Category

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Exploring Nano 3: Nanotubes

March 9, 2008

The third project in the Exploring Nano series is now complete! It combines music and narration synchronized with pictures and animations to explain graphite, graphene, nanotubes, their history and their properties. To visit the exhibit in Second Life, click here.

Note:  The exhibit has actually been around for a while – the main thing that’s just happened is that the musical soundtrack was completed.

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SIMS

February 8, 2008

The Surface & Nano-Analysis Lab on Nanotechnology Island has a detailed and life-size model of a SIMS instrument. SIMS stands for Secondary Ion Mass Spectroscopy.

To use the SIMS instrument, you put a sample in it, it then throws charged particles (called “primary ions”) at the sample, those knock a bunch of stuff off the surface of the sample (and even from under the surface), some of the stuff knocked off is charged (called “secondary ions”), and then the secondary ions are sucked into a mass spectrometer for analysis. The end result is that you find out what’s on the surface of the sample (and the relative amounts of each thing). By moving the primary ion beam across the surface, you can even find out how surface composition changes from place to place.

You can analyze tea (Earl Grey), a polymer blend, and a metal grid using the SIMS instrument on Nanotechnology Island. You can also click on the various parts of the SIMS instrument – when you do so, a voice tells you what you clicked upon. Over in the Gallery in other wing of the main building, there’s a model that illustrates the principles of SIMS. You can fire a Bi+ ion or a C60 buckyball at a sample and see the mayhem that ensues as particles go flying all over the place.

Click here to visit the main building on Nanotechnology Island now.

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The Airborne Particle Monitoring Station

January 31, 2008

On the southeast side of the Nanotechnology sim, there’s an Airborne Particle Monitoring Station. It’s a trailer with instruments that NPL uses to measure air quality.

Nearby, there are examples of common sources of air particles: industry, airplanes, vehicles and sea spray.

The main instrument on display inside the trailer is a Scanning/Sequential Mobility Particle Sizer (SMPS). The air (carrying particles of various sizes) first goes through a Differential Mobility Analyser (DMA), which throws away all but the particles of a certain size. (You can adjust the particle size being kept.)

You can click on the numbered squares to get a notecard about the various parts of the DMA. By step 7, the particles of the desired size are all headed to the right, towards the Condensation Particle Counter (CPC).

The CPC counts the particles entering it by coating them in butanol and then using a laser detector to sense the coated particles. Once again, you can click on the numbered squares to learn about the parts of the CPC. There are also signs on the walls giving more explanation, plus an example of how the Airborne Particle Monitoring Station was used to track air quality surrounding the Guy Fawkes celebrations of 2006 (involving the launching of firewords and the burning of effigies).

Click here to visit the exhibit now.

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We Have a Ball

January 27, 2008

The gallery in the main building of Nanotechnology Island has a giant model of buckminsterfullerene.  What’s that?

Buckminsterfullerene is a molecule made of 60 carbon atoms, so it is also called C60 (where the 60 is subscript).  The shorter name ‘buckyball’ is also used, because it resembles a ball.  It’s named after Richard Buckminster Fuller (1895-1983), the scientist, architect, and philosopher who popularized the geodesic dome (which is similar in structure).  Buckyballs were discovered in 1985 by Harold Kroto, James R. Heath, Sean O’Brien, Robert Curl and Richard Smalley.  The distance from the middle of an atom on one side to the middle of an atom on the other side is about 0.7 nanometres.

If you look at the model, you’ll see that there are both pentagons (five-sided) and hexagons (six-sided), and none of the pentagons share an edge… just like a soccer ball.  How many pentagons are there?  One way to find out is by visiting the model in Second Life and counting them.

By the way, we’re leaving room in the gallery for your exhibits – and NPL may even pay you for them!  For more information about that, see the webpage about the NanoLands Challenge.

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Atomic Force Microscopes

January 24, 2008

Atomic Force Microscopes (AFMs) can “see” things that are smaller than a nanometer – which is much better resolution than what’s possible with optical microscopes. How do they do that? How are AFMs used?

In the East Wing of the Main Building on Nanotechnology Island, there’s a Surface and Nano-Analysis Lab with a model of an AFM. (There’s also a model of a SIMS, which I’ll write about some other day.)

If you sit on the stool at the AFM, you can click on various samples to analyze them -an image appears on the computer screen, and you also get a notecard explaining what you see. Samples include a human hair, tungsten nanoparticles on a gold surface, and a PVC/PC polymer blend.

You can also click on the doors of the AFM enclosure, then click on the head of the AFM to see the innards a bit.

Outside the Surface and Nano-Analysis Lab is an exhibit which explains the principles of AFMs. The basic idea is that a needle is dragged across the surface of the sample being analyzed, a bit like a record player. The up-and-down motion of the needle tells you about how the height of the surface varies from place to place. (This is all roughly speaking, for clarity.)

AFMs can actually be operated in a variety of different imaging modes. The exhibit animates four of those modes: constant height, constant force, intermittent contact, and force modulation. Explanations of the modes are also given.

You can check it all out now, at Nanotechnology Island.