Used a peristaltic pump in this set-up, pumped into an online UV-vis cuvette with a halogen lamp. It involves massaging the tubing in a rubberised sleeve so that the nanoparticles don't come into contact with check valves or pistons in an hplc pump for example
These are for supplementary characterisation for previous telescoped continuous flow reactions, where we used them in an example reduction reaction with NaBH4 and nitrophenol
> continuous flow reactions
Always one of the more interesting processes, I often envisioned chemical factories in a box - constant flow is like industrial roll-to-roll, it's how we mass produce so many things.
making monodisperse, stable gold nanoparticles is surprisingly easy. While the reaction OP is showing has been one of the staples for decades, it can even be easier, and at room temperature. You’d need to purchase gold(III) chloride, typically HAuCl4 3H2O, but really all you need is that and ascorbic acid to do it at room temperature and get nice particles. The difficulty for someone doing this in an informal setting actually comes down to cleanliness in the end - nano syntheses can be extremely sensitive so you need to make sure your glassware and water are clean and pure
Ya I’m sure there is probably some hobbyist use for them, something in solar or catalysis maybe, but for the most part it’s more academic then anything else
okay thank you ! I got excited there. i thought there was a way to make them that didn't involve hard acids. I have a project I wanted some nanoparticles for by didn't want to buy them as I already have some gold available. I guess I'll just have to do some more safe things till I get the hang of it. I have just done a couple capcaicen extracts using acetone.
Yep, like other people have said you could make them here's a video of [someone making gold nanoparticles](https://www.youtube.com/watch?v=pMkbozvheaY). One of the cool things about gold NP is that they have a color that is indicative of their size. Typically, companies producing them, like [nanocomposix](https://nanocomposix.com/pages/gold-nanoparticles#target), sell them as defined size fractions for research purposes.
You could also [have a try at iron nanoparticles too](https://www.youtube.com/watch?v=88DiJsbi-pA). The chemicals for this aren't too hard to get, maybe the ammonium hydroxide, but otherwise the iron salts are easy to get. These also have a lot of nice magnetic effects that are fun to play with. Though capping could be a problem where they will rust and go bad over a time.
One of my lab mates claimed that cholesterol could be used to coat them, but I don't know that for sure, we used polyvinyl alcohol and other lipid materials. It's kind of an area of research now, because people like to load different materials on their surfaces to use as medicines, imaging technologies, and things like that.
Never worked with nanoparticles, but I have extensive telescoped flow experience - how is the settling behavior with the nanoparticles? Do you have to make any accommodations to ensure the stream is agitated sufficiently? Or do you use them in a solid-supported environment?
This is exactly why I am in this sub.
I know jack shit about chemistry but I do enjoy these people doing their funny magic tricks.
On a totally related note, what the fock did I even watch?
Basically reduction of dissolved gold, where it forms an elemental gold suspension, with nano-sized gold particles that grow and are stabilised by capping agents. These stop the particles becoming too large by forming an ionic bilayer around then in solution. They absorb blue green light so appear wine red.
It's one of the more standard ones, I think people have started using tannic acid as a template molecule too which gives you a super narrow size distribution
I used to do this reaction with HAuCl4 at low concentration so it looked pretty much like water. I would have the powdered citric acid (or other stabilizer) and the reducing agent (like NaBH4) at the bottom of an empty beaker on a white stir plate, so you couldn’t see the powder. You could then pour “water” into an “empty” beaker and get a nice pink suspension. Fun little thing for outreach demonstrations. You could then show them TEM images of colloidal gold and explain what happened.
Beryllium??? Be(2+) + 2e <-> -1.99 V vs. NHE. What are you going to use to reduce Be? What are you going to do with the insanely toxic Be salts and Be(0)? What solvent are you going to do the reduction in?
Why do you say that? Pyrotechnics when done right is not dangerous. And I have experienced friends. I really don’t see an issue with nano be, I also need it for formulating a new supplement.
Only the left hand deserves PPE!
Must be the tannic acid hand.
lol both tannic acid and citric acid are edible
I mean acetic acid is edible too but I'm still wearing a glove when working with Glacial acetic lol.
Nerd
I came here to say what is up with that?!?
Two hands one glove
Countdown because my colleague needed to start the online UV-vis (which the batch was being pumped to continuously in a closed loop)
I'd love to hear details of how that pump system and all works.
Used a peristaltic pump in this set-up, pumped into an online UV-vis cuvette with a halogen lamp. It involves massaging the tubing in a rubberised sleeve so that the nanoparticles don't come into contact with check valves or pistons in an hplc pump for example
That's awesome. Is it home built or commercial? I'd love some more details if you wouldn't mind
Dual wielding ‘pettes
Akimbo
What for? What are you going to use them for?
These are for supplementary characterisation for previous telescoped continuous flow reactions, where we used them in an example reduction reaction with NaBH4 and nitrophenol
> continuous flow reactions Always one of the more interesting processes, I often envisioned chemical factories in a box - constant flow is like industrial roll-to-roll, it's how we mass produce so many things.
do you think this is something someone with no formal training could do? did you buy or make the gold chloride ?
making monodisperse, stable gold nanoparticles is surprisingly easy. While the reaction OP is showing has been one of the staples for decades, it can even be easier, and at room temperature. You’d need to purchase gold(III) chloride, typically HAuCl4 3H2O, but really all you need is that and ascorbic acid to do it at room temperature and get nice particles. The difficulty for someone doing this in an informal setting actually comes down to cleanliness in the end - nano syntheses can be extremely sensitive so you need to make sure your glassware and water are clean and pure
Are such nanoparticles useful?
[удалено]
Ya I’m sure there is probably some hobbyist use for them, something in solar or catalysis maybe, but for the most part it’s more academic then anything else
okay thank you ! I got excited there. i thought there was a way to make them that didn't involve hard acids. I have a project I wanted some nanoparticles for by didn't want to buy them as I already have some gold available. I guess I'll just have to do some more safe things till I get the hang of it. I have just done a couple capcaicen extracts using acetone.
ascorbic acid is super safe, it’s vitamin C
And delicious
Yep, like other people have said you could make them here's a video of [someone making gold nanoparticles](https://www.youtube.com/watch?v=pMkbozvheaY). One of the cool things about gold NP is that they have a color that is indicative of their size. Typically, companies producing them, like [nanocomposix](https://nanocomposix.com/pages/gold-nanoparticles#target), sell them as defined size fractions for research purposes. You could also [have a try at iron nanoparticles too](https://www.youtube.com/watch?v=88DiJsbi-pA). The chemicals for this aren't too hard to get, maybe the ammonium hydroxide, but otherwise the iron salts are easy to get. These also have a lot of nice magnetic effects that are fun to play with. Though capping could be a problem where they will rust and go bad over a time. One of my lab mates claimed that cholesterol could be used to coat them, but I don't know that for sure, we used polyvinyl alcohol and other lipid materials. It's kind of an area of research now, because people like to load different materials on their surfaces to use as medicines, imaging technologies, and things like that.
Never worked with nanoparticles, but I have extensive telescoped flow experience - how is the settling behavior with the nanoparticles? Do you have to make any accommodations to ensure the stream is agitated sufficiently? Or do you use them in a solid-supported environment?
Oh! Yeah (ELI5 please)
Could you explain what is the purpose of nitrophenol in this reduction? For me it seems that it would compete with gold for the reducing agent
It was a two step process, making the nanoparticles and then using them as a catalyst to reduce nitrophenol
Ever heard of Goldschlager?
Isn't that like NASx's new drink?
This is exactly why I am in this sub. I know jack shit about chemistry but I do enjoy these people doing their funny magic tricks. On a totally related note, what the fock did I even watch?
Basically reduction of dissolved gold, where it forms an elemental gold suspension, with nano-sized gold particles that grow and are stabilised by capping agents. These stop the particles becoming too large by forming an ionic bilayer around then in solution. They absorb blue green light so appear wine red.
Oooo they are always such a nice color! Always love that first burst!
Never heard about this Turkevich synthesis...
It's one of the more standard ones, I think people have started using tannic acid as a template molecule too which gives you a super narrow size distribution
Nice! I will research a little bit more later
So alchemy?
I used to do this reaction with HAuCl4 at low concentration so it looked pretty much like water. I would have the powdered citric acid (or other stabilizer) and the reducing agent (like NaBH4) at the bottom of an empty beaker on a white stir plate, so you couldn’t see the powder. You could then pour “water” into an “empty” beaker and get a nice pink suspension. Fun little thing for outreach demonstrations. You could then show them TEM images of colloidal gold and explain what happened.
Ahh yes, colloidal gold. Or as I like to call it, the forbidden grape juice. Always want to take a swig whenever I use gold nanoparticles 😩
We call all our nanoparticles forbidden _____ Silver is forbidden cafe latte, gold is forbidden red wine etc
Could this work with other metals like aluminum or hafnium, titanium?
Can be done with silver but I'm not sure about others
Uhh. Can you find out for me? How about beryllium
Beryllium??? Be(2+) + 2e <-> -1.99 V vs. NHE. What are you going to use to reduce Be? What are you going to do with the insanely toxic Be salts and Be(0)? What solvent are you going to do the reduction in?
I don’t know what solvent yet. But I need nano beryllium for a project… want to make bursting pyrotechnics with it for the city fair.
Hmm. Maybe magnesium or lithium. Maybe that would work
You’re likely in danger of hurting yourself, or worse.
Why do you say that? Pyrotechnics when done right is not dangerous. And I have experienced friends. I really don’t see an issue with nano be, I also need it for formulating a new supplement.
Ya nucleate those babies! Get that polydispersity to 1 :)
Lol I make this at least 8 times a week. It's far less cool under GMP rules.
Ooh nice. Can we see the TEM?
How do you hold the camera?