[NewCandle] Rolled Al hydrolysis

[Keith Nagel]

So far, very little gas is generating after 24 hours.

This seems to confirm the received wisdom; that the oxide
film is stable from pH 4 to 8.5. It is also claimed
that acids attack the oxide, and alkalines attack
the aluminum ( makes sense to me ). So in the
former case you clean dissolution, and the latter
you get pitting ( this I have seen from cleaning
aluminum for those earlier anode glow experiments ).

So quite like those experiments, the oxide builds
to a thickness which prevents further corrosion.

I agree that it's good to play with this stuff even
if nothing out of the ordinary is expected; there
is no substitute for direct experience. I had no
idea that the corrosion would be so fast in plain water.

K.


-----Original Message-----
From: newcandle-bounces at ipdiscover.com
[mailto:newcandle-bounces at ipdiscover.com]On Behalf Of Nick Reiter
Sent: Friday, March 23, 2007 7:27 PM
To: New energy for the new world.
Subject: Re: [NewCandle] Rolled Al hydrolysis


Hi Keith,

Good speculations - lets see what happens when the
water is changed.

I'm finally setting up the four vessel test that I
hope will give me a notion about any possible
influences of rolled layers versus random crinkled
surfaces.  One more trip to the grocery store:)

The other night I had a notion that maybe a pure water
- Al hydrolysis cell could be maintained by periodic
hydroxide spalling jolts from an ultrasonic
transducer.  Of course, adding a little NaOH would
work too, I guess:)

It's a good exercise this... even if the basic
principles of hydrolysis are ho-hum, its good to
re-tuck them under one's belt and re-learn some
basics.  Makes it easier to get an idea if something
exotic like cavity constrained effects are kicking in.

N


--- Keith Nagel <NewCandleAdmin at ipdiscover.com> wrote:

> OK, the oxide layer has grown to the point
> where the reaction has diminished to just the
> occasional tiny bubble. I don't doubt that
> drying and heating the Al will get things moving
> again, as you'd be breaking the loose oxide
> skin by doing that. Either an acid or a base
> will do the same, and this experiment seems
> to indicate that when you dissolve Al in the
> acid or base solution it's the water that's
> doing the corrosion and the acid/base just
> cleans up the resulting oxide leaving a fresh
> surface
> for more corrosion. Would an anhydrous acid
> _not_ corrode Al? And is what's limiting the
> reaction now the film thickness or the solubility
> limit of the water? I can test this, by replacing
> the old water with fresh tomorrow morning and
> watch the results.
> 
> K.
> 



 
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