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Nanoparticles (07/10/17 22:30:32) Reply
    Fearful thing those nanoparticles. 1-100 nm in diameter, with entirely weird properties. Toxic as hell says the FUD. Penetrates everything and induces mutations and causes cancer.

    Well, a red blood cell is about 6000 nm in diameter. A thrombocyte is about 1000 nm in diameter. A bacterium - Eschericia coli is about 1000 x 1000 x 2000 nm

    http://book.bionumbers.org/how-big-is-an-e-coli-cell-and-what-is-its-mass/

    Anyone using caramel (sugar colour) for their sauces? That's carbon nanoparticles

    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3337553/

    "We report the finding of the presence of carbon nanoparticles (CNPs) in different carbohydrate based food caramels, viz. bread, jaggery, sugar caramel, corn flakes and biscuits, where the preparation involves heating of the starting material. The CNPs were amorphous in nature; the particles were spherical having sizes in the range of 4–30 nm, depending upon the source of extraction. The results also indicated that particles formed at higher temperature were smaller than those formed at lower temperature. Excitation tuneable photoluminescence was observed for all the samples with quantum yield (QY) 1.2, 0.55 and 0.63%, for CNPs from bread, jaggery and sugar caramels respectively. The present discovery suggests potential usefulness of CNPs for various biological applications, as the sources of extraction are regular food items, some of which have been consumed by humans for centuries, and thus they can be considered as safe."

    as a beginning.

    Then we can go further, but not today.
e

Re: Nanoparticles (15/10/17 15:10:43) Reply
    The brown colour of whiskys is - I believe - carbon nanoparticles. So is the golden colour of the Pilsener beers.

    Those afraid of carbon nanoparticles had better stick to vodka or vodka lookalikes.
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Re: Nanoparticles (15/10/17 15:17:11) Reply
    Making nanoparticles is easy for some - like caramel. Others are more tricky because those tiny particles tend to aggregate into lumps that have lost some of the desirable properties of nanoparticles. So they need to be stabilised. This is an art or a science in itself. The stabiliser must be present before the formation of the particles.

    It's like with the caramel. If you roast your flour too long on the frying pan, it all converts into coke, and it will be quite a chore to remove it from the pan. It's doable with my old cast-iron pans. I don't think modern PTFE-covered surfaces will endure the heat. And it is better to be outside if those PTFE layers start to decompose above 350 degrees Celcius.
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Stabilisers (23/10/17 18:13:17) Reply
    If nanoparticles are left to themselves, they tend to aggregating. This can be remedied by coating. But if the particles are coated, then the surfaces are not exposed to the surroundings. If the coating is correctly chosen, it can be shedded - or substances can diffuse through it.

    Schrödinger's nanoparticle: Is it coated, or isn't it?
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something else - ebony (03/11/17 20:14:18) Reply
    We could be scared of a lot. Or do some research before start to work on/with anything. The other day I looked up ebony. It is supposedly a hardwood, one can make very lasting things out of it. Rare and protected, still possible to get to do models, chess figures all kinds of small projects. According to wiki:

    "Ebony, when ground into fine dust (for example, during sawing), results in a flammable and toxic powder which can float about in air for several days. Due to the high toxicity of ebony in powdered form, its use in construction work requires government certification in several South Asian countries."

    https://en.wikipedia.org/wiki/Ebony

    Somebody please tell me that if the bloody thing is heavy enough to sink in water, how its dust can float in the air for days?
have

Re: something else - ebony (04/11/17 20:34:34) Reply
    I'd think it is about particle size. Small particles will not sediment very quickly. I can see it in my home with the dust in the air - specially when the sun is low, like in winter and early spring.

    I don't know about ebony - but there are some interesting experiments related to kitchen hygiene.

    If you use a wooden carving board

    https://www.cooksillustrated.com/equipment_reviews/1568-carving-boards

    for your food salmonella-contaminated chicken, then bacteria live shorter on the board than if you use a polythene board. And, I'd think it is likely that wood in general, but specially tropical wood, contain strong chemicals to fend off bacteria and pests. So it would not surprise me if they are toxic to humans. Actually wood dust toxicity is a problem not only with ebony.

    This seems like an example of the general principle that plants defend themselves with chemicals. Not all of those are poisons to humans, but some are.
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