Grab 50 atoms from anywhere on (or in) the Earth and 30 of them are Oxygen; 10 of them are Silicon, and 3 are Aluminum. These three elements are the most abundant on Earth, and Oxygen is the third most abundant element in the Solar System. Planning for living out there is mostly about finding volatiles, organics and Nitrogen plus trace amounts of Phosphorus, Calcium and Potassium for life support, and because we'd like to live among living things, not just man-made systems... at least I'd like to, and I expect we'd be saner and healthier that way!
But back to those 43 of fifty atoms; they make up silly silicates (ceramics, glass and stone) and aluminosilicates (like the mineral feldspar), since Aluminum will cut in on Silicon, by turns rudely or politely, and make Geology, and the chemistry of the same, so much more interesting. In molecular nanotechnology Carbon is king, but it has problems. It oxidizes or burns; despite being strong and doing neat 3-D tricks, it doesn't do some things very well. It doesn't self-assemble like proteins will, or silicates. Silica forms strings and chains and sheets; leaves voids useful for sifting and for cabling with other polymers on the small and on the sly. It's what lab chemistry happens inside of, in the form of glass, or on. We historically have built with it, shaped and fired it, formed it into molten glass, and molested it chemically to make photovoltaic cells. It's everything, pretty much, that we need it to be, and it's everywhere, out there in space or on the Earth, that we want to be!
The last time I thought much about MNT design, I assumed that, like anything else, people would back different approaches with their time and money. Some of the futurists made it sound like the hardware and software of each approach would be like a software language and hardware platform, like the Old Wintel duopoly vs. Mac and Linux; now Google Android/Linux versus Apple, so-
Feldspar.adp (Aluminosilicate Design Protocol)- "Everything we need (almost!), everywhere we want to be..."
Adamantine.mnt (not dmnt, or dmnd for 'Diamond' 8-) is a copyright-protected diamondoid carbon-based design protocol. C, or Carbon.cdp is a similar, also copyrighted protocol shared by a consortium of public and private entities.
Protean.ptn and Banana.bnn are protein-based design protocols. Protean is copyright-protected and Banana is open-source.
Feldspar and Adamantine in this scenario would be competing to bring smart materials to market, and the latter is also competing with the 'soft' MNT to create universal assemblers, which I really doubt we'll see until the last half of the century (and therefore I'm probably wrong 8-). Feldspar and Adamantine aren't purely silicate- or carbon-based, but the materials are, and would be about products. Protean and Banana (B-eh? N-eh? N-eh?), the soft nanotech, and also involve genetic engineering, and integration. What I think I'm doing is simplifying a chaotic future, ten-twenty years on...
So, can we form long-chain inorganic silicate polymers? If we can, would they be a good replacement for plastics? It's what I'm thinking about, for the 73 Part Development of the Solar System... Assume that this is twice as heavy as mylar, but we can incorporate amorphous silicon-on-silicate (PV, 9-10% efficiency, at a daily are of 6 KW-hr/m^2 per, call it .57 KW-hr/m^2, ~18 MW-hr for a 100 meter sphere) into the structural sheeting for our aerostat. Mine the surface of Venus with robotic airships, export nitrogen and carbon, build with aluminosilicates that we can expect are in abundance in the planetary regolith.
Hydrocarbons don't go away, and neither do plastics, but they would be replaced as feedstock becomes more valuable as food (fertilizers) and scarce and dear. Replace the original plastic solar power bubbles with silicates, glass-fiber or fiberglass, and with amorphous silicon(thin film solar cells)-on-silicate structural sheeting. Build the Billig Tower (Climate Control/Dehumidifier) out of a small mountain of slag and mine-tailings.
Designed to provide water and hydroelectric power, and also hurricane deflection. Everyone will want one, and the cities not protected by one will demand that Atlanta or Jacksonville stop aiming storms at them!