A heat pipe can be bought, so complexity if any is not your worry. It costs very few dollar for >100W. It works without a pump
, advantage over a liquid flow and a chemical reaction.
Over a trimerization, they have the fundamental advantages that vaporization occurs over zero temperature diofference, is complete, and happens quickly (which offsets any comparison of absorbed heat). The trimer <-> monomer would have all these drawbacks.
All this makes heat pipes the standard solution, especially for processors in computers. If you don't find the pipes, buy complete coolers and throw the rest away.
Don't try to develop your own heat pipes: it takes time. For instance, sealing the pipe without evaporating the liquid is less than obvious. Treating the pipe's inner face for capillary circulation isn't neither.
See the three copper pipes on the picture? There, or at competitors, since all use the same technology:http://www.arctic.ac/de_en/freezer-7-64-pro.html
30€ unit consumer price, maybe 3€ manufacturing cost, this must leave 0.20€ per pipe
- universal solution because it's the best technology. I wouldn't even try to compete against that.