Sciencemadness Discussion Board

sonochemistry and its application ???

it_tu - 27-2-2008 at 03:17

Hi guys,
I am doing a research about application of sonochemistry. As i know so far, the mechanism for sonochemistry is the formation, growth and explosion of cavitation during the propagation of ultrasound.
according to "hot spot" theory: there are two active sites for sonochemical reactions:
- inside the bubble: due to very high pressure (about thousand atm) and high temperature (5000K)
- medium around the bubble: (liquid and gas) also due to high temperature and high pressure (but lower than that inside the bubble).
here, i would like to concentrate on the sonochemistry in heterogeneous medium (for example: solid-fluid). I just wonder:
- If there is any chemical reaction between solid and fluid? :(
- If yes, we can determine the energy needed for that reaction?
- Or what is the force the fluid particles act on the solid to break the bonding between solid particles themselves?
I really appreciate any comments on this stuff or any advice where I can find out more information about it.
:)

Reference Information

solo - 27-2-2008 at 03:36

Sonochemistry and its Application in Materials Science
Aharon Gedanken

Attachment: Sonochemistry and its Application in Materials Sciencegedanken.pdf (61kB)
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PHILOU Zrealone - 27-2-2008 at 09:05

As a side note ultraturaxing (special propeller blade) at 11000-30000 rpm provides about as much efficiency as sonochemistry. Behind the blade en in front of it you also get cavitation effects.

I remember some searchers at university that explained us to be able to achieve Grignard reaction with gross metalic Mg without the help of ether as complexating agent. The cavitation increased so much the surface area of the metal that it reacted imediately; this in association with the special conditions in cavitation bubbles...

Our research departement at university proved that ultraturaxion and sonication had the ability to increase unfavorised endothermical product vs favorised kinetic product from 0.01% to nearly 50% (maximum theorical yield for endothermical processes)...this fact is consistent with the activation energy of endothermical and exothermical reaction course (reaction and reverse reaction in equilibrium) becoming negligible in contrast with the involved energy. The rapid temperature decay being responsible of the litteraly frozing in state of the speudo equilibrium between the two endothermical and kinetical products. I don't recal me the molecule in question, but is was bisubsitued aromatic and I remember that it has to do with ortho, para and meta position of the third introduced component to make it trisubstitued.

[Edited on 27-2-2008 by PHILOU Zrealone]

[Edited on 27-2-2008 by PHILOU Zrealone]

roamingnome - 27-2-2008 at 20:23

As PHILOUZrealone has typed propeller blade...

the navy starting seeing the effects of cavitation on its propeller blades.

so "If there is any chemical reaction between solid and fluid?"

that bubble crashing into the surface was eating up there brass propellers. So some Navy guy told me they have little air holes on the blade edge. This creates the sound of "rain" on the radar, gives less friction to the blade, and prevents cavitation... so he said...

im trying out hydrogen generation of methanol/water solutions and mild ultrasound helps simple electrolysis along nicely....

ummm... i think its a wide open field right know with plenty of discovery's to be had...

soon you may desire hundreds of watts of energy pulsing threw a titanium horn..no?

[Edited on 28-2-2008 by roamingnome]

PHILOU Zrealone - 28-2-2008 at 05:25

Quote:
Originally posted by roamingnome
As PHILOUZrealone has typed propeller blade...

the navy starting seeing the effects of cavitation on its propeller blades.

so "If there is any chemical reaction between solid and fluid?"

that bubble crashing into the surface was eating up there brass propellers. So some Navy guy told me they have little air holes on the blade edge. This creates the sound of "rain" on the radar, gives less friction to the blade, and prevents cavitation... so he said...

im trying out hydrogen generation of methanol/water solutions and mild ultrasound helps simple electrolysis along nicely....

ummm... i think its a wide open field right know with plenty of discovery's to be had...

soon you may desire hundreds of watts of energy pulsing threw a titanium horn..no?

[Edited on 28-2-2008 by roamingnome]


Sonication of MeOH and H2O will result H2 but also in oxydations reactions via peroxydes...H2O2 + CH3-O-O-CH3, CH3-O-CH3, CH2=O, CO, CO2

One of the most intriguishing effect is the one you get on Deuteriated or Tritiumated compounds...you get nuclear reaction (fusion) as new atoms are formed...same occurs with sparks of high voltage into water/salt mixes...alchemy is back but processes are not fully understood yet...cold or low energy fusion reactions...

[Edited on 28-2-2008 by PHILOU Zrealone]

roamingnome - 28-2-2008 at 17:59

Good, every one sleeping or didnt give a damn, because i meant to say SONOR not RADAR
its like dolphins are the people of the ocean type of thing....

in the methanol/water thing i tried, it was just a 8 watt piece of crap that vibrated conventional electrolysis electrodes for better mass transport, but higher ultrasound powers will cause reaction on its own.

i totally believe in cold fusion! :D
its all about quantum tunneling probability. if you get the nucleus's close enough for enough time the probability of fusion increases.

so if deuterium is hanging out in the lattice spaces of a palladium electrode with the
right "alchemy" i say they fuse

chemrox - 28-2-2008 at 19:26

Solo-thanks for the ref. What unit is a W/cm? W stands for what?

12AX7 - 28-2-2008 at 19:48

Where?

W = watt, the SI unit of power. cm = 0.01 m, an SI-derived unit of length.

W/cm may indicate a linear or inverse volumetric power density. In the first case, it could be: lambda (W/cm) * L (cm) = P (W) (lambda typically being used to represent a linear something density type of quantity); in the second case: rho (W*cm/cm^2) * A (cm^2) / D (cm) = P (W) (rho typically being used to represent volumetric properties), where A is an area (e.g., cross-sectional) and D is a seperation, so that A*D defines the volume of the region in question.

Tim