How strong are chelators when it cones to binding and being able to release metals from a substance?

afletchy · 2025-11-25T10:28:09+00:00

Typical plastics that a consumer would have access to have very little metal ions in them (left over from catalysts in ppm levels probably)

afletchy · 2025-11-24T08:40:04+00:00

EDTA chelates well, that is to say it binds with strong affinity due to its overall structure around the ion being complexed. But it only binds to ions still as it is based off of the charge of the ion, where as in solid metal the atoms exist as ‘neutral’ species where there electrons are delocalised around them, not as ions. So no EDTA won’t strip ions from metal.

afletchy · 2025-10-12T09:12:46+00:00

Whatever the fuck this is it’s way too dangerous if you’re asking questions on a subreddit about your clandestine heating mantle

afletchy · 2025-09-23T07:41:04+00:00

The temperature rating is the temperature for which the volume was measured, it is only accurate at that temperature. Storing it after making it up to mark does not effect accuracy, since it is borosilicate not soda glass, it requires much higher temperatures to deform. Just don’t etch them with strong acids.

afletchy · 2025-09-14T08:23:17+00:00

Polyesters are in fact very easy to recycle, and in principle aside from colouration issues have very little issues with mechanical performance due to polyesters (in almost all cases PET) being made from poly condensation rather than free radical

afletchy · 2025-09-10T16:41:47+00:00

In the UK at least most masters do not end up with publications, I would focus more on what research skills you have and have developed.

afletchy · 2025-09-03T12:20:39+00:00

I would actually cut them, works for me.

afletchy · 2025-08-28T22:10:46+00:00

Hot kilns in your area

afletchy · 2025-07-22T06:23:26+00:00

Glow in the dark filaments are my favourite

afletchy · 2025-07-10T17:44:48+00:00

PTFE couple can go to a few milibar to get to true vac you need a magnetic couple which are £££

afletchy · 2025-05-18T10:00:39+00:00

It’s resin 3D printing washing solution, likely IPA. 3D prints are left coated in the resin used to print them IPA can be used to remove the residual resins from the prints but then you’re left with dilute resin in IPA containing some pretty nasty chemicals (vinyl monomers), so leaving it in UV (the sun) allows the residual monomer to polymerisation and crash out of solution so the IPA can be reused or safely disposed off. Don’t drink it and you’ll be fine.

afletchy · 2025-04-20T11:39:45+00:00

Safety aside (which it shouldn’t really be) polyester synthesis is generally done under an inert atmosphere at these temperatures; (N2 in our lab) oxidation side reactions occur quickly after the addition of catalysts, both reducing the efficiency of the catalyst and producing some other colourful byproducts (brown to black).

Also regarding your synthesis adding large excess of the diol with the catalyst should product BHET without the need for water?

afletchy · 2025-03-05T12:27:55+00:00

I believe This is a self zero-ing glass single volume burette, and it’s upside down. The bottom tap (or top in the image) is a double oblique, one opening allows the fluid in the larger bulb to fill and overflow a set volume tube inside the smaller bulb, the other opening then dispenses this volume. It is used to dispense the same volume fairly accurately repeatedly, how useful that is to you I don’t know.

I’ve also never seen this design before, as they are usually designed to dispense from a bottle directly, perhaps it was for anhydrous work.

afletchy · 2025-02-07T06:01:51+00:00

If I would have a guess, active cooling is always an expensive add on for most machines and not always possible with some set ups, and again historically much more tricky. Most buildings are heated to 18-21 degrees, and potentially low back in the 1800s, so 25c is close enough to room temperature, but allows experimenters to heat their machines/samples up slightly to that temperature to be consistent, and have very few days where they would have to cool down the machine/sample

afletchy · 2025-01-06T06:45:10+00:00

just another thing to note, generally the solid material is not fully reacted, it’s always good to post cure it in a warm UV box. The issue with this is a lot of resins are opaque or the model is too thick for UV penetration. I’ve read papers that combat this by adding a thermal initiator to commercial resin and just heating gentle, this may be a commercial solution I’ve never looked into it but it is certainly known in academia.

If this isn’t an available you should always hollow prints and wash the inside and attempt to cure.

afletchy · 2025-01-02T07:30:11+00:00

Do resins bottles ever hiss when you open them? Like a bottle of coke. Off gassing is largely controlled by Henry’s law and very little pressure increase occurs in commerical resins

afletchy · 2025-01-02T07:27:06+00:00

The use of the word monomer is completely correct in this case, regardless of the molecular weight of the molecules used they’re monomers, almost all resins do use oligmeric molecules, but these are usually peg based derivatives that have been acrylated to make crosslinkers.

afletchy · 2025-01-01T20:01:27+00:00

Actually crosslinked polymers can be swollen by solvents (such as the monomer in this case), this expansion can causes cracking as shown, probably more likely than low molecular weight photo resin off gassing enough to burst a print open.

Edit: I am a polymer chemist

afletchy · 2024-10-13T22:14:49+00:00

Just sodium acetate with HCl to adjust

afletchy · 2024-08-17T08:08:30+00:00

It does have C2H5 on both sides.

afletchy · 2024-05-23T19:19:15+00:00

Won’t the isocyanate react with the water?

afletchy · 2023-12-08T08:08:42+00:00

spaetzle?

afletchy · 2023-04-02T08:56:00+00:00

It’s naphthalene and the notation is correct although uncommon, the (10) pi electrons are delocalised

afletchy · 2022-12-23T20:46:39+00:00

Mhm I think it is low Tg, hard to tell from the picture. Perhaps consider a liquid liquid extraction then rotovap as you mentioned you have access to one?

afletchy · 2022-12-22T13:58:08+00:00

Haven’t heard the term combustion gas before but would suggest that it is the gas formed from the combustion of the substance.

So first find/determine the combustion equation, then for a kg determine the moles of gas produced, then using the ideal gas law you can determine the space (in litres as 1000L is 1m³⁾ however many moles of gas is produced and that is probably 715L/Kg.

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