On 3 veebr, 07:22, Phillip Thorne <petho...@[EMAIL PROTECTED]
> wrote:
> On Sat, 02 Feb 2008, Wildepad <noreplies> posed:
>
> >The ultimate garbage disposer is built -- [...]
> >The inventor admits there are some minor problems with the process,
> >and number 1,896 on his list of things to change is that the carbon
> >comes out as flawless 36 pound crystals. [...]
> >it's piling up at the rate of about 1000 tons a day.
> >What do you do with it?
>
> <http://en.wikipedia.org/wiki/Material_properties_of_diamond>
>
> At 3.52 g/cm^3, 36 pounds (16.33 kg) is 4639 cm^3 in volume -- a
> sphere 10 cm in radius or a cube 16 cm on an edge, or a 1-cm-thick
> square sheet 68 cm on an edge.
>
> "Diamondoid" (as an umbrella term for all forms of structured
> hexagonal and tetrahedral carbon) is the standard material in
> speculations of molecular manufacturing -- but it's *fabricated* in
> the desired end-form.
>
> There are applications for *small* amounts of diamond -- computer chip
> substrates (it's an excellent heat conductor), high-strength coatings,
> cutting surfaces. But today we use vapor-deposition techniques for
> those.
>
Because vapour deposition techniques are expensive and work only at a
small scale.
Get a source of cheap big diamonds and all of the above applications
work at a large scale.
> But diamond whose raw form is bulk? You can't melt it and reform it
> in molds, or extrude it as fibers. You *could* shatter it and use the
> fragments on industrial cutting surfaces -- they already use titanium
> nitride, carbon nitride, and artificial "industrial diamond" (produced
> IIRC as tiny yellow-brown crystals that are useless for jewelery).
>
> Can you carve it into sheets? (Using a diamond-edged saw, of course;
> laser? water-jet?)
What about cleaving? Diamond has good cleavage along octahedral
surfaces. Cleave a layer of suitable thickness off a triangular face
of the octahedron, and you have your sheet.
Of course, there are the three other cleavage planes (parallel to the
edges of your sheet). If you use excessive force and strong blows at
the sheet, it will crack and break. But so would a stone plate, glass
plate or pottery plate.
> Is bulk diamond as good as glass, or does it
> shatter too easily?
My impression is that diamond is better than glass. It does not match
the toughness of metals, nor of composites like wood or bone, but I
suspect that among stone, glass and ceramic materials, it is
reasonably good.
BTW, sawing is also restricted to definite directions - which are
different than the cleavage directions.
> You could process it (laminate, coat) and use it
> for home windows. Or, if the sheets aren't large enough, photo frames
> and display cases.
>
> The "diamond baseball trophies" of _Unbounding the Future_ become
> practical (although the effort of *cutting* the bulk diamond might
> make them expensive).
>
> Pure monocrystalline diamond shatters easily (unbeatable hardness,
> poor toughness), so Klaatu's assertions in "Day the Earth Stood Still"
> notwithstanding, it wouldn't make good money. (Once you carved it
> into tokens. And doing so would probably be more expensive than
> minting mentals. Implant impurities to change its color to form
> pictures? Use intersecting lasers to carve the mint-marks inside?)
>
> Facets of the Times Square New Year's ball?
>
> Cut it into thermal-transfer rods. Will merely abutting two rods
> permit sufficient heat flow? The thermal conductivity of diamond
> (2000-2500 Wm/m^2K) is superior to any other solid, but what about
> liquids? Would it work better than the liquid cooling loops available
> for high-end PCs? (It'd certainly be simpler.)
>
> It's a good electrical insulator. Better than ceramics? Use it in
> electrical transmission systems.
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