The reaction is complicated, is exothermic , and also exhibits swings in ph as a function of time.
During the original moon shots, NASA tested for and found that it would be possible to make portland cement on the moon using the particles there. Construction! But, where do we get the water?
If lime could be mined and refined, then it has a cementious reaction that doesn’t require water, but rather CO 2 .
Powder processing • Procedure: --grind to produce ceramic and/or glass particles --inject into mold --press to improve density by better packing (ideally close packed) --sinter at elevated temperature to further densify by shrinking pores • Sintering : useful for both clay and non-clay compositions. • Compare powder processing to working with clay: PARTICULATE FORMING
Thus, if atoms are given enough energy to move (i.e. during sintering), then grain boundaries grow and pores shrink.
Eventually, pores are pseudo spherical and grain boundaries exist at every initial particle junction. Why? Is this important?
Process is atomic diffusion, not liquid flow.
Introducing glass formers (TiO 2 , Bi 2 O 3 ) will improve pore reduction and boundary growth as atomic diffusion is faster in the liquid, and the liquid flows. Now we are combining techniques, though.
4 Million tons worldwide–11000 tons/day (=96% of total Ti use)
68% of worldwide TiO 2 production capacity is in the hands of five US-based companies: Dupont (1 million metric tons annually), Millennium Chemicals, Huntsman Tioxide, Kerr-McGee Chemical and Kronos Inc.
As a pigment of high refringence Titanium dioxide is the most widely used white pigment because of its brightness and very high refractive index (n=2.4), in which it is surpassed only by a few other materials. When deposited as a thin film, its refractive index and color make it an excellent reflective optical coating for dielectric mirrors. TiO2 is also an effective opacifier in powder form, where it is employed as a pigment to provide whiteness and opacity to products such as paints, coatings, plastics, papers, inks, foods, and most toothpastes. Used as a white food coloring, it has E number E171. In cosmetic and skin care products, titanium dioxide is used both as a pigment and a thickener. It is also used as a tattoo pigment and styptic pencils.
This pigment is used extensively in plastics and other applications for its UV resistant properties where it acts as a UV reflector.
In ceramic glazes titanium dioxide acts as an opacifier and seeds crystal formation. In almost every sunblock with a physical blocker, titanium dioxide is found both because of its refractive index and its resistance to discoloration under ultraviolet light. This advantage enhances its stability and ability to protect the skin from ultraviolet light.
Snails, seashells, krill, etc, have evolved methods for fabricating phenomenally complicated ceramic structures (mostly silica and calcia), usually at ambient conditions.
Research continues into trying to understand how this is done, and especially how we can mimic it.
Proteins have been harvested, and even improved, for low temperature fabrication of SiO x .
The protein R5 is especially good at converting Si and O from solution into crystalline SiO x .
Applying the protein to a dental surface and exposing to a Si rich solution offers the possibility of low temperature SiO x deposition and thus simple tooth regeneration.
Opposite halves of DNA base pairs are attached to a substrate and a ceramic particle, respectively. The particles can then be selectively bound to a surface in a cost effective aqueous procedure, avoiding the complexity of high energy and vacuum based deposition techniques like CVD, PLD, and sputtering.
Spiders are great at forming SiO x containing fibers. Harvest these for mechanical or fiber-optic applications.