Chemistry people, I need your help

[Python14]

Alright, I'm working on a useless project and I need some help. I'm looking for a chemical that is not electrically conductive, has a specific heat higher than water, is relatively fluid(consistency of a heavy motor oil at the thickest), and here's the kicker....is relatively available and inexpensive. Anyone?

Also, anyone wanna guess what I'm doing?

[Will Wood]

I could be wrong, but I do recall doing experiments with electricity and liquids, and I beleive many acids were not electroconductive, I am not sure about the heat though. Would an acid work ok or would that be bad? I could probably search and remember a specific one I've used if acid would work.

[cphilip]

...has a specific heat higher than water, is relatively fluid(consistency of a heavy motor oil at the thickest),

Not certain which criteria your asking for there... boiling point? Auto ignition Temperature? But.... going to assume boiling point for now...


Mineral Oil might be something that fits. Its got a low conductivity and meets most of your other criteria nicely

... in a clean dry base oil has a very low conductivity of 10-14 mho/cm.

Not certain thats enough for you but that is low. Often its thicker counterpart "Dielectric Grease" is used. But not certain right off hand how closely they compare but I thought they had some simlarities except mineral oil if fluid and viscous like you wanted.

[Will Wood]

The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius

[Python14]

I might look into Mineral Oil, I'm just not totally enthuised about that 10 ohm/cm.

Btw, I'm building a computer that instead of using air or water as a coolant, the Mobo, VGA, and such will be submerged in a liquid bath that is circulated through a modifed refridgerator.

Even with the theoretical Overclock(in theory I should be able to hit 1 ghz), it will be less than half the speed of my current, air cooled computer(2.4 ghz)

[Will Wood]

Use Sapphire! Heh.

So then as a coolant, running through a refridge, I'm guessing an acidic liquid would be bad...I have no idea what you could use now.

[cphilip]

I might look into Mineral Oil, I'm just not totally enthuised about that 10 ohm/cm.

Btw, I'm building a computer that instead of using air or water as a coolant, the Mobo, VGA, and such will be submerged in a liquid bath that is circulated through a modifed refridgerator.

Even with the theoretical Overclock(in theory I should be able to hit 1 ghz), it will be less than half the speed of my current, air cooled computer(2.4 ghz)

Ok got cha.... how about Propylene Glycol then?

[Hamster Huey]

Almost by definition, acids have a relatively high conductivity. There are exceptions, but they tend to be funky organic acids. And then there's the problem with things eating away at your computer components.

You actually have a rather difficult problem. While finding high resitivity fluids isn't too hard, finding fluids that fit your application well is going to be rather difficult. You could immerse your computer parts in an organic solvent like xylene or toluene and have no worries about resistivity, but you'd have to worry about your plastic bits dissolving, your cooling fluid evaporating, or even getting an explosion. You could up the molecular weight to mineral oil or even cooking oil and get rid of your volatility problem, but you may still have problems with the stabiility of your plastics. It's also pretty hard to beat the specific heat of water.

Have you thought about using polyethylene glycol or even just glycol dissolved in distilled water? Distilled water is surprisingly nonconductive. I can't speak for how many ions you would pick up from the metal bits of your computer, or how much corrosion you might get, but it's worth a thought.

I would also suggest adding chemical inertness with plastics/metal, low volatility (at operating temps), and low flammability as another important qualifier for whatever liquid you choose.

[Python14]

hahaha, sapphire! Wanna foot the bill on that one?

Actually though, if I did use sapphire, I'd have to have some kind of condenser because it's boiling temp is like 49*C....well within the temperature range of my CPU.

I'm not too concerned about long term longevity. It just has to run stable for a couple weeks while I show it off. Glycol might do the trick though.

[Thordic]

I was buggin my dad about it before (chemical engineer) because it sounded like a cool idea.

He said that anything that would work well is probably extrememly difficult to get your hands on. I'll keep looking, but from that statement I'm guessing it wouldn't be all that cost effective.

[cphilip]

Well interestingly enough... Apple is using Propylene Glycol coolant in their new G5 dual processor liquid cooled model I just discovered...

When you said coolant thats when it came to my mind. And then I looked into thier coolant and found the MSDS for it and there she was!

PROPYLENE GLYCOL 57-55-6 < 2.0%
DI WATER 7732-18-5 > 45%
.
NOTE (1): Small quantities of Delphi 151 Heat Transfer Fluid, as used in LCS, are fully enclosed in sealed housing and are not accessible unless the unit is damaged or altered.
NOTE (2): ALL WHMIS required information is included in appropriate sections based on the ANSI Z400.1-1993 format.
NOTE (3): Information on this product is being claimed as proprietary. All pertinent hazard information has been provided, per the Trade Secret requirements of U.S. Federal Occupational Safety and Health Administration Standards (29 CFR 1910.1200) and Canadian WHMIS (CPR 12 and 19). Information on this mixture will be released when the conditions specified in these Standards are

[brianlojeck]

Cray's are (or were) cooled with Freon.

You'd need a condensor, but it'd sure stay cool... ;-)

[Jack_Dubious]

i believe cphillips first suggestion of mineral oil may be the best solution. Ive seen mineral oil used in total immersion cooling setups so i dont think there is a problem with its conductivity.

JDub

[Python14]

lol, if I was gonna use freon....I'd just say screw it and do phase change on my gaming rid.

I will probably go with Mineral Oil though.

[cphilip]

Why not at least check into this with these guys?


"Delphi 151 Heat Transfer Fluid"