Stories tagged metal

Earlier this year, researchers created a multiwalled carbon nanotube (MCNT) aerogel", dubbed "frozen smoke", that had a density of only 4 mg/cm3, making it the world's lightest solid material.

New metal - which is 99.9% air - is so light that it can sit atop a dandelion fluff without damaging it: Using an innovative fabrication process developed at HRL Laboratories in Malibu, California, researchers created a "micro-lattice" structure of interconnected, hollow nickel-phosphorus tubes.
New metal - which is 99.9% air - is so light that it can sit atop a dandelion fluff without damaging it: Using an innovative fabrication process developed at HRL Laboratories in Malibu, California, researchers created a "micro-lattice" structure of interconnected, hollow nickel-phosphorus tubes.Courtesy Photo by Dan Little © HRL Laboratories, LLC
Not anymore. Frozen smoke is no longer the world's lightest sold material, as researchers from the University of California at Irvine, HGL Laboratories, and California Institute of Technology have developed a material with a density of only 0.9 mg/cm3. This material, composed of a lattice of interconnected, hollow nickel-phosphorous tubes, is 100 times lighter than StyrofoamTM, and is 99.99% open volume, but exhibits impressive strength and energy absorption properties. Potential applications for this material include battery electrodes, catalyst supports, and acoustic, vibration or shock energy damping.

The nanotubes that make up the 0.01% of the material that isn't air have a wall thickness of 100 nanometers - or 1,000 times thinner than a human hair. These tubes are angled to connect at nodes to form repeating, three-dimensional cells shaped similiar to an asterisk.

The research team's paper, "Ultralight Metallic Microlattices," appears in the November 18, 2011 issue of Science.

News Release: Multidisciplinary team of researchers develop world’s lightest material

Mar
04
2011

This started as a reply to Bryan's comment on the Freaky Frogs post, but it quickly turned into its own blog entry...

Here's Bryan's comment:

I thought the whole BPA freakout was an interesting look at how we think about environmental and personal contaminants like this. People seemed to get all up in arms about BPA in water bottles and bought tons of new plastic or aluminium vessels to replace them. But that switch over raised some questions for me.

Where did all those old bottles go? In the trash?

How much energy does it take to make those aluminium bottles? Is it lots more than the plastic ones?

How many bottles can you own before it'd just be better to use disposable paper?

Bauxite: It takes a lot of energy to get the aluminum out of this rock to make a can.
Bauxite: It takes a lot of energy to get the aluminum out of this rock to make a can.Courtesy US Government

And my response...
It took some searching, but I did find one article discussing a life cycle analysis from Australia which showed that, in a comparison between aluminum, stainless steel, and plastic, plastic has the smallest carbon emissions footprint, uses the least water, and produces the least manufacturing waste. However, it was unclear whether this comparison included recycled metals in its evaluation. Steel and aluminum are 100% recyclable (vs. plastic, which loses quality every time it's recycled), so over time and on a large scale, their use would lead to less material waste.

Steel plant: This place is probably recycling steel RIGHT NOW.
Steel plant: This place is probably recycling steel RIGHT NOW.Courtesy Matthew Baugh

It's also interesting to note that recycling metals uses significantly less energy vs. what it would take to smelt "new" metal. To paraphrase this reference, recycling steel and aluminum saves 74% and 95%, respectively, of the energy used to make these metals from scratch. As it turns out, we recycle about half the steel we use in a year in the US, and so almost all the steel we use contains recycled content. In contrast, we recycle just 7 percent of the plastic we use.

And then there's glass--we have lots of options, really.

Bottled water: Probably the least efficient option all around.
Bottled water: Probably the least efficient option all around.Courtesy Ivy Main

I can't speak to how much material was wasted when people discarded all those bottles (I think I recycled mine?). Personally, I do think that making reusable bottles in general uses less energy than is needed to make all those disposable plastics and recycle them--at least in terms of lifetime footprints. Of course, when it comes to a strict comparison between reusable bottles, switching to a new bottle will always consume more energy than just sticking with your old one.

Unfortunately, it turns out that most plastics, even the ones labeled BPA-free, leach estrogen-mimicking chemicals. So if you're looking for a long term solution, it may be best to just avoid plastics altogether. This does seem to be one of those cases where we have to consider our own health vs. the environment and pick our battles wisely. If people want to switch once to avoid health problems, at least they're still sticking with reusable bottles. Readers, do you agree?

Ice cold water: Wait, what's in here?
Ice cold water: Wait, what's in here?Courtesy Clementina

Of course, it would be great if choosing a water bottle were the only drinking water issue we faced. The other day I read about a study by Environmental Working Group, which found that the carcinogen chromium-6 contaminates tap water throughout the US. Are we exposing ourselves to this toxic metal by drinking tap water instead of pre-bottled water? Or is chromium in the bottled water, too? What about other unregulated pollutants in our water?

I guess my point of going into all this is that it's complicated to make these decisions, and we'll probably never be able to avoid every single toxic substance. But does that mean we shouldn't try to make drinking water safer?

For now, I'm gonna stick with the steel and aluminum bottles that I already have and try to get the most out of them. Luckily, I live in the Twin Cities, which don't rate high on EWG's chromium map. Every day, I learn more about my health and the health of our environment, and hopefully by searching, I'll find a direction that hits on a fair compromise.

Lincoln learning: One of the new penny backs will show the young Abe Lincoln studying while splitting rails in Indiana.
Lincoln learning: One of the new penny backs will show the young Abe Lincoln studying while splitting rails in Indiana.Courtesy U.S. Mint
The Buzz has buzzed in the past with talk about pennies – their usefullness and efficiency in being part of monetary system. It looks like they'll be around for at least another year as the U.S. Mint has released sketches showing the redesigns of the back of the penny that will commemorate the 200th anniversary of Abraham Lincoln's birth. And here's the link the U.S. Mint website that will give you close-ups of the new penny backs.

May
10
2008

If only pictures had sound: Look--all the stars are holding up their lighters!
If only pictures had sound: Look--all the stars are holding up their lighters!Courtesy NASA
Isn’t it embarrassing when you realize that you’ve been operating on a misconception for, well, a really long time? Like, “Oh, my god, his girlfriend’s name is ‘Sara’! I’ve been calling her Starla!” or “Full House’s Uncle Jessie was supposed to be a functional illiterate? Of course!”

It’s the pits, you know? And it has happened to me again.

Ever wonder where hardcore metal bands come from? Not me—I always assumed they usually came out of Scandinavia, or horrible little Chicago suburbs. It seemed like a pretty safe bet, but now I’ve been forced to reevaluate the whole thing, and I’m not looking like a very smart guy. No, it’s clear to me now, after reading about a recent geophysical theory, that the most hard core hardcore metal bands must come from the planet Mercury.

How do I know this? It’s obvious. New geophysical models suggest that it “snows” iron on Mercury. That’s pretty hardcore, but it doesn’t stop there—here on Earth, our snow falls in delightful little flakes, like tiny, pretty fairy hats. With snow like shaped that, it’s amazing we can even listen to metal without our heads turning inside out, melting, and then bursting into explosive gas. See, on Mercury the snow falls in cubes. Cubes of iron. And these cubes don’t just drift lazily through the atmosphere like boring Earth snow. In fact, they don’t move through the atmosphere at all, because on the planet Mercury, it snows iron cubes underground.

It’s thought that the core of Mercury may be made up of molten iron and sulfur. As this white hot brimstone brew approaches the surface of the planet, it cools, and the iron condenses into cubes that sink back into the core. These conditions may explain why Mercury has such a weak magnetic field (Mercury is the only other terrestrial planet in our solar system that possesses a global magnetic field, but the field is 100 times weaker than Earth’s for some reason). They certainly explain where the best blood drinking, arson committing, vocal cord scraping metal bands come from (specifically, I imagine that the planet periodically vomits broods of spike covered babies from volcanoes). Our fluffy, whimsical, puff ‘n stuff snow, on the other hand, is clearly the reason why we produce the people that make the computers that make easy listening music.

Iron snow. Underground. Great.