I've been wondering if this would work at all, considering that antifreeze is used to cool cars which get pretty hot and alcohol Ethanol rubbing alcohol specifically because in this list http://www.engineeringtoolbox.com/specific-heat-fluids-d_151.html here it says its pretty cold compared to some other things so would it work properly or am I just being stupid?
Well if you know your chemistry a bit, Antifreeze is used to raise the boiling point and freezing points of the Water based liquids it is poured into. in this case (not a huge car Guy) but it is poured into the cooling system of a car. this is similar to the effect of pouring salt on snow during the winter, it raises the boiling points and freezing points of water. (which during the winter you normally have snow everywhere) since the freezing point is now lower. ice can no longer form in icy temperatures and eventually the snow will melt and just be absorbed by the ground. (if it's really cold outside you want to use heavy salts like calcium chloride cause it lowers the freezing point of water drastically). back to the car analogy, if you didn't pour anti-freeze in your car during the winter the Cooling system could potentially freeze. so you add anti-freeze (thus why it's got its name) to raise the boiling and freezing points of the water based liquid in the cooling system. so during the winter your cooling system doesn't freeze.
what you wish to do i wouldn't recommend it, cause ethanol is a flammable organic compound, it could cause a fire if you apply the right amount of heat. and also i''m pretty sure you don't want to inhale an ethanol and antifreeze homogenous mixture which could be released from a computer radiator. cause inhaling anti-freeze I'm pretty sure you could die.
I don't know that much about it, but if it were worth doing I'm sure people would do it. The idea with liquid cooling isn't to have a liquid which can store more energy, or be colder, it is to move energy from the hot part to the cold part efficiently. Water seems to work pretty well for that.
The reason cars use anti-freeze is because they have to deal with a much larger temperature range than what you would have in a computer. You need to increase the boiling point so the water in the radiator doesn't boil and you need to lower the freezing point so that in winter your coolant doesn't freeze.
Dont use alcohol in your loop - and here is why
Alcohol has a low evaporation temperature, so what you will get is evaporated alcohol gas in your loop. Gas will be able to form because the loop is not pressurized and you will end up with 'air' in your pump. Not only that but 'air' that is highly flammable.
As far as antifreeze goes, that just lowers the freezing point of your liquid. waste of time in a cooling loop. It will NOT raise your boiling temp - that is only achieved through pressurizing the system.
The other thing you would have to check is if any of the fluids you want to use have micro particles which will gum up your cooling fins, or have the ability to cause corrosion through electrolysis.
Just use distilled water.
Don't use boiling point lowering mixtures if you don't know how to calculate it and know exactly what you're doing, you'll cause overpressure and accelerated corrosion in your loop and break everything.
If you have however studied physics and chemistry to the point where you know what you're doing, it's definitely a great way to reduce temperatures (well, no antifreeze, but only the anticorrosive additives of antifreeze, and no rubbing alcohol but glycol). I use it myself, it makes for a very quite pump because the pump is at lowest setting because most of the circulation is caused by convection and by the expansion tank (which you'll need), and the temperature at continuous maximum load on very hot days, is never more than ambient temperature.
also what everyone else mentioned, ethanols boiling point is fairly low, with the amount of heat being produced from a CPU you are going to have Ethanol as a gas in your loop. which is never a good thing to have anyways.