materials science
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Laterite: The Tropical Forge
Laterite is the red earth of the tropics — a soil forged by heat, rain, and time. It forms where the climate swings between wet and dry seasons, leaching rock until only the most stubborn minerals remain: iron, aluminum, and silica. Nearly all laterite carries a rusty coloration because of its high iron oxide content…
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Saprolite
Saprolite is a chemically weathered rock. Saprolites form in the lower zones of soil profiles and represent deep weathering of the bedrock surface. In most outcrops, its color comes from ferric compounds. Deeply weathered profiles are widespread on the continental landmasses between latitudes 35°N and 35°S. Conditions for the formation of deeply weathered regolith include a topographically moderate relief flat enough to prevent erosion and to allow leaching of the products of chemical weathering. A second…
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Flame Test
A flame test is relatively quick test for the presence of some elements in a sample. The technique is archaic and of questionable reliability, but once was a component of qualitative inorganic analysis. The phenomenon is related to pyrotechnics and atomic emission spectroscopy. The color of the flames is understood through the principles of atomic electron transition and photoemission, where varying elements require distinct energy levels (photons)…
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Silicene is a two-dimensional allotrope of silicon, with a hexagonal honeycomb structure similar to that of graphene
Contrary to graphene, silicene is not flat, but has a periodically buckled topology; the coupling between layers in silicene is much stronger than in multilayered graphene; and the oxidized form of silicene, 2D silica, has a very different chemical structure from graphene oxide. History Although theorists had speculated about the existence and possible properties of free-standing silicene, researchers…
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p-Phenylenediamine (PPD) is a derivative of aniline used in kevlar, hair dye and henna substitutions among other things, the derivatives of which are used in antiozonants among other horrors
p-Phenylenediamine (PPD) is an organic compound with the formula C6H4(NH2)2. This derivative of aniline is a white solid, but samples can darken due to air oxidation.It is mainly used as a component of engineering polymers and composites like kevlar. It is also an ingredient in hair dyes and is occasionally used as a substitute for henna. Production PPD is produced via three routes. Most commonly, 4-nitrochlorobenzene is treated…
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Zinc, maybe
No proof for the need of zinc in human cells was shown until the late 1930s. More than most ever wanted to know about zinc. A work in progress.
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The trefoil knot fold is a protein fold in which the protein backbone is twisted into a trefoil knot shape
“Shallow” knots in which the tail of the polypeptide chain only passes through a loop by a few residues are uncommon, but “deep” knots in which many residues are passed through the loop are extremely rare. Deep trefoil knots have been found in the SPOUT superfamily. including methyltransferase proteins involved in posttranscriptional RNA modification in all three domains of life, including bacterium Thermus thermophilus and…
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Fibroin: The Quiet Titan of Silk
Fibroin is the insoluble, structural protein that gives silk its legendary strength, spun out by creatures like Bombyx mori and its many moth cousins. Raw silk is a duet: sericin, the sticky glue, and fibroin, the twin brins—the filaments—at its core. Those brins, whose name traces back through Old French and possibly Gaulish roots meaning…
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Sericin: The Silk That Sticks (and the Chemist Who Named Its Ghost)
Sericin is the glue‑protein of the silkworm world — the adhesive sheath that binds the twin fibroin brins into a single raw silk fiber. Bombyx mori paints its cocoon with it in layered strokes, a protein lacquer. Silk is never just silk. It’s a composite: 70–80% fibroin, 20–30% sericin. Fibroin is the architecture; sericin is…
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Biomining or what I suspect “healthcare” (and much of the “food” industry) has been up to for a very, very long time
Biomining is the technique of extracting metals from ores and other solid materials typically using prokaryotes, fungi or plants (phytoextraction also known as phytomining or biomining). These organisms secrete different organic compounds that chelate metals from the environment and bring it back to the cell where they are typically used to coordinate electrons. It was discovered in the mid 1900s that microorganisms…