Came across an interesting paper on the use of Cu-water and Al2O3-water
nanofluids in low velocity liquid cooling microchannel heat exchangers today.
The gist is, adding a high thermal conductivity nano scale metallic or
non-metallic particle to coolant can boost thermal conductivity in low flow
rate systems. The research paper goes on to say the impact is not as significant in higher velocity systems
which turn out to be dominated by flow rate. "Investigation of a Counter Flow Microchannel Heat Exchanger Performance Using Nanofluid as a Coolant" was put out by Mushtaq Hasan, Abdul Rageb and Mahmmod Yaghoubi from the Thi-Qar University Iraq, Basra University Iraq and the Academy of Sciences of Iran.
The paper references other investigations of nanofluid
coolants, including; Aluminum Oxide water (y-Al2O3-H2O), 1%
diamond-water, Copper-water (Cu-H2O), and Carbon nanotube-water
(CNT-H2O). Interesting read for anyone curious about where the next level of low flow watercooling technology could possibly be headed.