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Titania Nanotubes for Hydrogen Sensors?
Roland Piquepaille writes "Everybody is talking about carbon nanotubes these days. But what about titania nanotubes? Penn State researchers think they have a great potential for sensing hydrogen . According to this news release, "titania nanotubes are 1500 times better than the next best material for sensing hydrogen and may be one of the first examples of materials properties changing dramatically when crossing the border between real world sizes and nanoscopic dimensions, according to a Penn State materials scientist." And now, the very good news: titania nanotubes are cheap. So they'll be used in industrial quality control in food plants and as weapons against terrorism. My summary contains some more details."
Now we will be able to detect the terrorists at they attempt to crash Zeplins into our buildings!
Weapons Against Terrorism! Oh goody! We're saved!
Where to I invest?
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
Screw titania. When are they gonna get the kryptonite nanotubes?
A lit match works for hydrogen detection as well as many gas hydrocarbons. It is very versatile.
How cheap could these be? I mean titanium itself is not a cheap metal (about $4 a pound apparently), but I imagine making nanotubes out of titanium oxide probably does not consume much titanium. The process has to be a bitch though.
I don't see anything about cost in the paper either.
Overexuberance on the author's part?
HBI's Law: Frequency of calling others Nazis is directly correlated with the likelihood of the accuser being Communist.
I think titania here is titanium dioxide, TiO2, which is most commonly used as a pigment- most opaque white pigments contain titanium dioxide, also known as rutile. I had no idea you could make it into nanotubes though.
"FDA staff reviewers expressed concern about the number of patients who were left out of the study because they died."
Why everything has to be about terrorism?
1. Throw around a buzzword, like nanotubes.
2. Mention fighting the terrorism.
3. Well, we all know what comes at step 3, don't we?
This is why everything has to be about terrorism.
Allah Akbar = Profit?
---------
(I used Allah Akbar not because I think it is in itself pro-terrorist, but because it is the most recognized token for the situation, so please.)
You can't handle the truth.
Titania, it turns out, is Titanium Dioxide, used commonly as a white pigment. Read more about it at the Wikipedia.
Seriously though, this press-release sets off my B.S. sensor. A typical scientific press-release would include some basic stuff, like what Titania Nanotubes are. Additionally, from my understanding of how carbon nanotubes are made, and how they exist, I'm not sure that Titanium could be used to make nanotubes. Neither could Silicon, which is the chemically more similar. Carbon nanotubes can exist because Carbon gets to form 4 and only 4 bonds. The extra electron orbitals (d-orbitals in spectroscophy language) would screw this up.
Additionally, I don't think that combustion (say in cars, mentioned in the article), results in any free hydrogen, it should be water, carbon dioxide, and unburnt fuel.
Galium Arsenide is the material of the future, and always will be.
titania nanotubes are 1500 times better than the next best material for sensing hydrogen
Oxygen?
My daughter's name is Titania, sounds like she's been getting up to some serious mischief.
Everybody is talking about carbon nanotubes these days.
Yeah, can't walk down the street or ride a subway without hearing that incessant chatter about carbon nanotubes.
I'm still at a loss as to how detecting hydrogen helps combat terrorism. Would someone care to enlighten me?
Video Game cheats, hints a
Well, sir, there's nothing on earth Like a genuine,Bona fide,Electrified, Titaniafied, Nanotube! What'd I say? Ned Flanders: Nanotube! Lyle Lanley: What's it called? Patty+Selma: Nanotube! Lyle Lanley: That's right! Nanotube! Miss Hoover: I hear those things are awfully loud... Lyle Lanley: But tt detects hydrogen clouds. Apu: Is there a chance the tube could bend? Lyle Lanley: Not on your life, my Hindu friend. Barney: What about us brain-dead slobs? Lyle Lanley: You'll be given cushy jobs. Abe: Were you sent here by the devil? Lyle Lanley: No, good sir, I'm on the level. Wiggum: The ring came off my pudding can. Lyle Lanley: Take my pen knife, my good man. I swear it's Springfield's only choice... Throw up your hands and raise your voice! All: Nanotube! Lyle Lanley: What's it called? All: Nanotube! Lyle Lanley: Once again... All: Nanotube! Marge: But Main Street's still all cracked and broken... Bart: Sorry, Mom, the mob has spoken! All: Nanotube! Nanotube! Nanotube! [big finish] Nanotube! Homer: Nano... D'oh!
You need to get your BS sensor checked; the research is real and legitimate.
Here's a reference to the original article, which is available online:
2003 Craig A. Grimes, Keat G. Ong, Oomman K. Varghese, Xiping Yang, G. Mor, Maggie Paulose, Chuanmin Ruan, Elizabeth C. Dickey, Michael V. Pishko, James W. Kendig and Andrew J. Mason, "A Sentinel Sensor Network for Hydrogen Sensing," Sensors, vol. 3, pp. 69-82. PDF format
Why is Slashdot posting these news release stories that are summarized and submitted by Roland Piquepaille? And for that matter, where are these details on his web site that he purports to have? All I see are direct quotes and linked pictures. This is the second one I see now. Is this a trend? Is this how one can get stories posted here? I'll go and read news release sites like Eureka Alert and quote generously from it, add a couple of picture links, and submit it here.
A lit match works for hydrogen detection as well as many gas hydrocarbons.
Actually, Hydrogen requires a higher fuel to air ratio than gasoline. It also disperses nearly instantly(well, except in confined/sealed areas of course)- whereas gasoline etc sink and pool(which is why your natural gas/propane water heater has that nice little picture of a gasoline can etc).
Oh, and since it's still not known enough- the Hindenburg burned because it was painted with the chemical equivalent of rocket fuel(the chemical composition of the paint etc is very close to solid rocket fuel)- not because it was full of Hydrogen, which, by itself, doesn't burn.
When it DOES burn, it burns a)instantly b)practically invisibly, c)with no smoke. Watch those films of the hindenburg, and note the a)slow b)bright yellow c)sooty fire.
It's interesting to note that hydrogen's qualities make it much safer should there be, say, an accident with a truck carrying it. It dissipates as it leaks, versus the major fire hazard/toxic waste problem created by a gasoline spill.
Please help metamoderate.
There are two things that are of help here. Firstly is the size of the tubes, when you are in the nano- or pico- regimes, there are a lot more surface features (corners, edges) per atom than there are in the bulk metal. As most reactions (catalytic or non catalytic) occur on surface features, having as many small particles as possible makes sense.
The other factor that is a help here is that the oxide is used. Introducing impurities into metal (consider the oxygen an impurity) does two things, changes the electron affinity of the metal so it can bind ligands better (or worse - also useful) and introduces point 'defects' - places where the crystal lattice is interrupted. These 'defect' sites actually provide reaction points for in this case, hydrogen.
Nice piece of chemistry!
Hydrogen entering an array of titania nanotubes flows around all the surfaces, but it also splits into individually charged atoms and permeates the surface of the nanotubes. These hydrogen ions provide electrons for conductivity. The change in conductance signals that hydrogen, above the background level, is present.
Sounds very similiar to how a fuel-cell works, but instead of pumping through lots of hydrogen to produce as much electricity as possible they're just using a little bit of hydrogen to generate a tiny current (or does it just change the conductivity?).
I want to know what this material does when feed pure hydrogen.
they are fair.. but I prefer to wait for Oberon nanotubes.
meh
I didn't see any links to the sources yet on the blog or the article so here is the homepage for Dr. Craig A. Grimes. There are two recent pdfs about the titania nanotubes on his publications page.
I am too lazy to figure out valences but a
quick google shows that theoretical calculations
predict them to exist and be semiconducting,
and someone has done TEM of those tubes so they
do exist and have been characterized. That said,
you'll have to look deeper for more info cause
I don't really care.
BTW, most oxides and dichaclogenides which exist
in layered crystal structures can be "rolled" up
and form nanotubes.
(1) The press release isn't particularly well done; most aren't.
(2) The articles mentioned in the press release (which were the important part of the release) are rather better. Of course, these also assume that the reader has at least some understanding of what "titania nanotubes" are, and that the specific rules for covalent bonds applicable to carbon don't mean all that much for transition metal oxides.
(3) Combustion "doesn't result in any hydrogen"? Perhaps, but how will we know without sensors that can detect trace (sub-ppm) levels of hydrogen in the exhaust?
These sensors aren't all that novel (as the S&A-B article at least points out, several other gas sensors based on a resistance change in a metal/metal oxide semiconductor have been developed), but they're relatively easy to prepare and don't poison easily - so it's at least moderately impressive. So, yes, they do exist, and the press release is where most or all of the BS is to be found.
It's simply amazing and can detect hydrogen from 1 ppm to 4%. Luckily there is just enough floating around to guarantee success every time. Amaze your friends, take it outside, show-off as you brilliantly hold the detector in hand and proclaim, "Yes, we are not in a vacuum."
Did I mention that your friends would be amazed?
As a muslim I must correct you. A more correct transliteration would sound like this. Allah-huu-akhbar. (key part you missed being the huu which sounds like who).
If anyone wants to know what that means... it's simply god is great or allah is great. Technically allah isn't a god as there is no sex associated with allah (god implies a masculine deity).
Hmmm... Pie...