Scientists ignite aluminum water mix

Scientists ignite aluminum water mix
Los Alamos National Laboratory chemist Bryce Tappan ignites a small quantity of aluminum nanoparticle water mixture. In open air, the compound burns like a Fourth of July sparkler.

( —Don't worry, that beer can you're holding is not going to spontaneously burst into flames, but under the right circumstances aluminum does catch fire, and the exact mechanism that governs how, has long been a mystery.

Now, new research by Los Alamos National Laboratory explosives scientist Bryce Tappan, published as the cover story in the prestigious German journal of chemistry Angewandte Chemie, for the first time confirms that —the speed of a chemical reaction—is a primary function in determining nanoaluminum combustion burn rates.

"It's been long understood that nanoscale aluminum particles, 110 nanometers and smaller, are highly reactive. Aluminum particles at this scale have been used in novel explosives, propellants, and pyrotechnic formulations," said Tappan. "The understanding of the combustion mechanism impacts how we look at the design of ever smaller aluminum particles like molecular aluminum clusters as well as possible nanoaluminum applications like hydrogen fuel storage devices—and this might be a little 'out there'—but also energetic formulations that could use extraterrestrial water as the oxidizer in rocket fuel."

Tappan and his co-authors, Matthew Dirmyer of Los Alamos, and Grant Risha of Penn State University, made this discovery by looking for the "kinetic isotope effect" in nanoaluminum particles 110, 80, and 38 nanometers in size. The particles consisted of a "core-shell" structure with an elemental aluminum core and a two to five nanometer oxide shell. The particles are mixed with deionized water, H2O, or deuterium, D2O, to the gooey consistency of cake batter.

The kinetic isotope effect is observed in a chemical reaction when an atom of one of the reactants (water) is substituted with its isotope (deuterium, or "heavy water") and the two reactions are compared for differences. This effect is considered one of the most important tools in determining chemical reaction mechanisms.

Tappan and his team obtained burn rates by putting water/deuterium nanoaluminum mixtures in small glass tubes, placing the tubes in pressure vessels, igniting the nanoaluminum with a laser and taking measurements as the mixture burned.

For many years it's been proposed that other mechanisms like oxygen diffusion through the particles, or tiny aluminum "explosions" in the mixture might govern the rates of the burning process. "Now we know that are a major player," said Tappan.

Scientists ignite aluminum water mix
When dry, aluminum nanoparticles look like simple dark gray dust.

"Knowing much more about the mechanisms at work in metal combustion gives you a chance to refine the models that govern these reactions," Tappan added. "This fundamental knowledge gives us a window on how to better control these processes."

Explore further

Explosive nanotechnology: Highly reactive nanoenergetic formulations based on periodate salts

Journal information: Angewandte Chemie

Citation: Scientists ignite aluminum water mix (2014, July 1) retrieved 15 October 2019 from
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Feedback to editors

User comments

Jul 01, 2014
Could this be an internal combustion fuel? Naw...

Could it explain the witchery behind the hydrino demonstrations?

-Well according to many peer-review scientists and observers, nope-

Jul 01, 2014

"Experiments have also been conducted using powdered solid fuels [for internal combustion], such as the magnesium injection cycle."


"Even fluidized metal powders and explosives have seen some use."

-See Lrrkrrr? There's lots of people around way smarter than me. Even smarter than you. All you gotta do is look to find out how mundane you actually are.

Jul 01, 2014
If, like me, you couldn't get the video to play, try this:

Jul 02, 2014
I wonder if aluminium or magnesium will dissolve in liquid ammonia, as does sodium and potassium. This could make a real-neat rocket fuel with 'medium test' peroxide as oxidant...

( Liquid ammonia, mind, NOT ammonia solution ;-)

Jul 03, 2014
This comment has been removed by a moderator.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more