Abstract
Although most of liquids show a decrease in the surface tension with increasing temperature, dilute aqueous solutions of higher alcohols with more than four carbon atoms are known to exceptionally show the opposite behavior; the surface tension increases with the increase in temperature. In nucleate boiling, possible dry patches developed under the bubbles are expected to be wetted by a liquid supply due to the Marangoni effects induced by both temperature and concentration gradients at the bubble interface, provided a good wettability is maintained. This particular characteristics, the so-called "self-wetting" characteristics, may allow an outstanding cooling performance not only in microgravity environment but also the terrestrial condition. A series of performance evaluation experiments have been conducted for conventional heat pipes with self-wetting fluids as a working fluid, and some results are promising.
