LOL yeah I built a $12M facility here, but that work was actually done in the old lab. I'm serious though once you understand reactive ion etching and what makes the machines tick it wouldn't be too hard to build a cheap system to deposit silicon on a pipe and dry etch it. Sputtering the silicon avoids all the nasty gas issues that go along with plasma enhanced chemical vapor deposition (PECVD. The RIE requires a florinated gas like CF4 or SF6 and oxygen but these gasses don't require anything too special for handling. Still outside the realm for the average home handyman but definitely not in the realm of multimillion dollar high tech facilities either.
IIRC anodize is alumina with a dye in it. Alumina wouldn't be a great heat conductor but it might be decent and certainly easier to do than what I'm suggesting. I should get off my butt and try some experiments. The other part of my plan is to use a partial vacuum ( can you tell I'M partial to vacuum??) to lower the boiling point of the heat exchange fluid (water?) to around 70 degrees C or so and using a couple of check valves (one on either side of the solar collector pointing in the direction of the flow path through the loop, steam bubbles that form in the heated tube will act as the motive force to circulate the water. No pump. When solar radiation is available the water circulates and when it's not it doesn't. KISS principle. True some of the solar energy gets used in moving fluid but some other form of energy would be used anyways in another method. A freind of mine tested the concept. He used it to circulate water from his campfire to a radiator in his tent. We call that Gucci camping! Ahh the luxury.....hey what are you gonna do in a Canadian winter? Joe Mike Redler wrote: > Hi Joe, > > Your research is a little outside of my range of expertise. So, I gave > your message to my finance. She has a PhD in Chemistry and runs a > chromatography lab. > > All she had to say was "Wow! He's got access to some nice equipment.". I > think she's jealous. > > I may be way off but, your description reminds me of black anodize. > > Anyway, it looks promising. > > Good luck. > > -Redler > > > Joe Street wrote: > >>Hi Mike; >> >>I don't have any references I can recommend but I'll tell you what I >>did. I dry etched silicon using flourine ions in a reactive ion etcher. >>Making use of native polymer contamination of the surface and carefully >>controling the presence of oxygen radicals I was able to form a dense >>structure of columns roughly 100 nm wide and 400 nm tall that when >>viewed with an electron microscope look something like a forest. The >>nanoconvolution of the surface on a scale less than the wavelength of >>visible light results in an extremely antireflective black surface >>similar to a moth's eye. (BTW this is why moths see so well in the dark) >>The silicon material absorbs all the incoming radiation in the visible >>and longer wavelengths and even most of the ultaviolet I'd guess as low >>as 198 nm although I haven't tested it. Silicon is roughly similar to >>iron in its heat conducting properties so this film would be very good >>for a passive solar system. I think I could build a machine to sputter >>silicon on pipes and etch it in situ if I had the resources. >> >>Joe >> >>Mike Redler wrote: >> >> >> >>>Hi everyone, >>> >>>I know of some descent resources for electronic circuits, software >>>development, and a bunch of other stuff. However, I've come up with >>>nuthin' for black bodies which contains both a practical guide for >>>passive solar collection and the analytical/mathematical tools for >>>theoretical modeling. Once I have that, I'm good to go, already having >>>one pretty good general text on heat transfer (J.P. Holman, seventh ed.). >>> >>>Joe, I know you mentioned some work you did with thin films (if my >>>memory serves me right). >>> >>>Can anyone point to a good on-line source? I'd even be happy with a >>>textbook recommendation. >>> >>>-Redler > > > _______________________________________________ > Biofuel mailing list > Biofuel@sustainablelists.org > http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org > > Biofuel at Journey to Forever: > http://journeytoforever.org/biofuel.html > > Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): > http://www.mail-archive.com/biofuel@sustainablelists.org/ > > _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
