Why aren't Gold Nanoparticles Gold?

[@ExplosionsAndFire]

Gold...... that isn't yellow..... I'm in

[@fraserbc]

Have we ruled out ghosts yet?

[@iain3713]

Hi Tom

[@belacickekl7579]

Surely you can fix that by attaching some azides?

[@graealex]

Judging from your last video, you love yellow chemistry.

[@gymprofessor329]

C U B E

[@AppliedScience]

I wish that I could give more than one "like". You're making the videos that I want to watch! I'm inspired to put more time into YT myself. Thanks!

[@SeanJonesYT]

It must be awesome to have Ben commend your work. Ben, I would love to see you two work together on some project - you guys work in such a similar way. It would be absolutely awesome to see, and it's inspiring to have you both spend your time teaching us things we would've otherwise never imagined learning about. Hats off to both of you!

[@lazyman114]

Hey Ben. I noticed that you are here on all the science/engineering youtube videos, which is absolutely fantastic! However, KZbin's algorithm makes it extremely difficult to find such channels on my own. It would be great if you could somehow create a community on discord where we can share and discuss such channels. There are quite a number of youtubers that make groundbreaking content and get 1-3k views at the MOST. Look at Chemical Force. He shows reactions that have never been seen before on video and he is only just now starting to gain traction after 3 years of work. I don't know how youtube's algorithm could be this bad, but there has to be a solution to keep talented content creators from getting discouraged.

[@excitedbox5705]

@@lazyman114 KZbin favors videos that appeal to a wide audience of brainless idiots.

[@notsonominal]

Dont worry Ben, I gave him another like ( .. but you're still the coolest cat on on YT:)

[@NEprimo]

i love you both

[@AppliedScience]

That's so cool! I had no idea short laser pulses to create metal nanoparticles was even a thing.

[@BreakingTaps]

Yeah! I forget how I stumbled onto it... think I was researching laser-induced forward transfer (ablating a thin film with _just enough_ energy to dislodge it from one substrate and fly over to a second nearby substrate) and stumbled onto this. Just seemed so neat and also easy too, my kind of technique :)

[@ThomasAndersonbsf]

@@BreakingTaps I was wondering if the size of the particles would play into smaller deposition to make semiconductors on a substrate or something :)

[@DIYBiotech]

Yall should do a collab where you put the gold nano particles in glass to recreate that Roman cup!

[@travismiller5548]

@@DIYBiotech it's called "fuming." I vaporize gold and silver with a torch and catch it on warm (borosilicate) surfaces all day every day. I feel like a jerk vaporizing precious metals, but all things considered it's a very low business cost. My first gram of gold lasted about 5 years, and I generated over a million dollars of merchandise.

[@athmaid]

@@travismiller5548 what do you do with it if you don't mind me asking?

[@SarahKchannel]

Now put a vial onto a peltier cooler/heater.. cycle the temp and see if there is a color shift when particles change size according to temperature... Likewise if you flash them with a laser or light source.

[@dddwidovich3514]

He dissolved it with iodine! or iodists. Then halogen,manganese as a catalyst?

[@patti441]

@@dddwidovich3514 what are you tanking about ?

[@patti441]

none of those cgemicals are present its just super fine metal dust in an suspension of water

[@dddwidovich3514]

@@patti441 ooookay, what do you like to hear, ambasador muchacha jalapenia

[@dddwidovich3514]

Lala

[@SwitchAndLever]

KZbin actually recommends something I want to watch for once! Well produced, engaging topic without becoming too entrenched in the scientific literature. Lovely stuff!

[@BreakingTaps]

Thanks! ❤

[@eulemitbeule5426]

That stuff might be really interesting as catalysts in chemical reactions: You usually use palladium on charcoal because it has a really big surface area, but you might be able to use a solution of Pd nanoparticles instead since that stuff seems to be able to tolerate organic solvents. Would be interesting to see what happens to the Pd nanoparticles during the reaction

[@carltauber2939]

The reason that the catalyst is adsorbed on a solid is so that the liquid or gaseous reactants can flow through the solid and be separated from it mechanically. If the catalyst is in solution you have to find a way to separate it from the products so you can continue to use it.

[@BE-dj6cp]

@@carltauber2939 perhaps a semi-permeable membrane (not permeable to nanoparticles) then use chromatography column to separate substrate from product. Not sure what that would be good for besides research. Alternatively, attaching nanoparticle to a porous membrane somehow w/o losing catalytic properties would be ideal for fuel cell application if cheap to produce. The major drawback of fuel cell tech is the catalyst is expensive platinum. If catalyst could be made cheaply = low sticker price production EV that runs on tank of methanol or H2 w/o big expensive environmentally unfriendly lithium ion battery pack

[@BreakingTaps]

*Addendum* - Commenters have pointed out that Pauli Exclusion is not for free electrons (electrons gas), it's only for electrons in atomic or molecular states. Oops! Addendum to the addendum: read comments in this thread for more clarification :) - I misdescribed the absorption vs transmission vs scattering phenomenon a bit. @Matthew Reavley says "the specific resonant frequency that you mentioned absorbs light of that frequency, that light isn't reflected back the direction it came, but rather the energy that's absorbed gets re-emitted in all directions. As a result, the intensity of that colour is reduced when you have a light source shining through it (eg. When the lycurgus cup is red, its because the intensity of the green light travelling in the same direction is now significantly reduced), and in all other directions (like when the light it outside the cup) , you only see the absorbed and emitted colour (green)"

[@kevinmartin7760]

I'm pretty sure it still applies, it is just that there are so many states available, forming a near-continuum of energy levels, that it makes no difference.

[@aaronclair4489]

@@kevinmartin7760 Kevin is absolutely correct. The Pauli exclusion principle holds for all fermions, such as electrons, protons, and neutrons. No two identical fermions can have the same quantum numbers (such as energy and spin). In essence, no two electrons can be at the same place at the same time with the same characteristics. In solids, the energy levels of electrons smear out. Instead of one orbital having one discrete energy in one atom, all the orbitals at that energy overlap, and their different energies shift minutely up or down to form energy bands. This is Band Theory, which describes electrons in solids. In a conductor, the valence band (full of electrons) and the conduction band (full of empty slots for electrons) touch, which is how electrons can flow from place to place. This is the origin of the electron sea. At least, this is my understanding of electrons in solids.

[@BreakingTaps]

​@@kevinmartin7760 ​ @Aaron Clair Ah ok, interesting! I remember seeing some information about levels "splitting" but I didn't quite understand at the time. But in context of your epxlanations that makes a lot more sense now, and describes why the "electron sea" actually can exist. Man I really need to go dig up my old physics books and re-read all this stuff, it's been far too long and I really struggled to put together a coherent explanation haha. Was definitely at the edge of my knowledge here :)

[@DanielHeineck]

@@BreakingTaps, exactly -- the density of states of a metal is characteristically very high around the Fermi energy, making them "practically equal" but not, technically. I think older versions of Kittel's "Solid State Physics" book are available online -- it'll have a pretty good explanation (it's also *every* English-speaking person's introduction to solid state physics)

[@alexdaharp]

@@BreakingTaps. IMO, what @Aaron Clair wrote is the typical explanation for band structure (more of a thing for crystals, the explanations for small molecules follow a similar theory called MO theory. When stuff is in between w.r.t size, stuff become a mess). The big thing is that plasmons need a partially filled conduction band. If you have a full valence band (a filled conduction band by definition is a valence band) you actually make Quantum Dots instead! In that case you can control the smearing of the electrons through controlling the size. A cool field is what happens when you get really small noble metal nanoparticles. When you get small enough, band structure doesn't really work anymore and you get some really weird effects. It's a really interesting field, you literally can count the number of atoms in the particles! I'm curious, have you checked the stability of your nanoparticles? I have heard that they tend to be a bit unstable unless you control the ionic strength or chuck something like a ligand (a molecule that bonds with the surface of the nanoparticle) into the mixture.

[@edoars46]

Man, ur explanation of nanomaterial synthesis is like telling me how to cook instant noodle, u made it really understandable, cheers 👍

[@excitedbox5705]

I use copper and silver nanoparticles for printing circuits, but you can also use copper as a thermal paste or add it to liquid coolant to increase the cooling properties. One of the coolest things about metal nanoparticles is that at really small sizes (

[@combin8or]

Suggestion- make an aerogel with nanoparticle inclusions. Semiconductor aerogels also exhibit surface plasmon resonance by virtue of their pore sizes. I’ve always wondered if one could dope silica (or another dielectric) aerogel with nanoparticles to exhibit some interesting properties. These days, particularly lithium or sodium.

[@colepearson2605]

I’m in a class called “Nanotechnology” right now, and this video got recommended to me right after I had a lecture on these nano particles! This really helped to explain surface plasmon resonance to me.

[@matthewreavley]

Also, another interesting thing you can do to tighten down your range of particle sizes is to use the fact that as nanoparticles get smaller, their melting point reduces (there's some unfriendly maths that show it's because surface energy increases relative to bulk energy). In short, with your 30-100nm particles, you could find the temperature where particles below 80nm melt and agglomerate, leaving behind those 80nm and larger nanoparticles. I believe this effect was first found in gold nanoparticles, and had something to do with someone forgetting to turn a hotplate off!

[@Gainn]

If you put gold into solution with aqua regia and then boil it off it agglomerates into a solid.

[@jonc133]

Great video and thanks for sharing. Back in my PhD days, I was working with gold chloride solutions and coating them on to nylon. When I did x-ray photoelectron spectroscopy on them, I noticed the sample came out different colours, depending on how long the xrays had been on them. The x-ray source was breaking down the gold chloride and gold particles were forming - the longer the x-ray were on, the larger the particles that formed, eventually forming a completely gold film.

[@dogodogo5891]

hi i read somewhere gold np can produces some invisible effect by combination of plasmon resonance stuff n metamaterial structue is that true?

[@22391pranav]

Your nanoparticles have a high polydispersity index, which is probably due to the method. You can use silver nanoparticles as antibacterial agent

[@albyboy4278]

Yes, nice to use silver nanoparticles to kill bacteria ... But don't let them touch your skin because they give you the silver skin disease ... Basically the skin absorbs the silver creating silver salts and replacing the skin color with the color of silver, metal color of silver . Once combined with the skin, the silver does not come off and remains with you for life. You have to be careful with the silver particles. There are examples of women left with silver-colored faces because the creams they used had silver salts.

[@angiasaa]

Actually, silver can be fatal, though admittedly you'd need a lot of silver to be killed by it. Silver nanoparticles absorb into the skin easily and will turn the skin blue. Silver poisoning is a thing. Look for Argyria or Argyrosis for more info on that. You have a good point however, people think they're being clever, but have no clue what it is doing to themselves. Beauty products.. :)

[@lastofthebest5102]

@@angiasaa LOL, ok. Whatever you say. Funny how you forgot to mention that flatwear (silverware) and plates/cups used by discerning people are constantly shedding nanoparticles each time they are used which mixes with food and is ingested. You must be one of those feds attempting to dissuade others from getting silver into their bodies so as to keep a population from figuring out how to collect more spiritual gains. Perhaps you have never heard of the Lycurgus cup?

[@davesmith440]

can you use gold particles as a antibacterial agent as well

[@hadinossanosam4459]

Would be really interesting to take transmission (and maybe reflection) spectra of these particles, I wonder whether they show a nice resonance pattern and/or let one identify the average particle size Also, how do you manage to find such above-and-beyond-awesome topics so consistently? The only other channel that manages that regularly is AppliedScience, and he uploads once a season ;)

[@BreakingTaps]

Agreed! I wanted to include some UV-Vis spectra in this video but my spectrophotometer is reaaaaaally old and didn't want to behave. Also it only prints out on thermal paper and I ran out :) Gold has a really well characterized set of transmission curves which are commonly used to identify the nanoparticle size without resorting to SEM/AFM images. It's not perfect, gold has a weird property of shifting the response if there is a mixture of sizes (rather than showing bimodal or a flatter curve) but it's generally Good Enough. Here's a good example: cdn.shopify.com/s/files/1/0256/1107/5658/files/gold_nanoparticle_absorbance_93074e71-b7d1-4b6c-bba1-171f028c4d5f.jpg?v=1570803718 And thanks, appreciate it! Sorta stumbled into this one on accident :) I wanted to try out the laser ablation technique, then did some more reading and saw how gold and silver behaved and the video sorta pivoted to talking about that since it was so cool :)

[@niki40935]

A more peculiar effect even is that anisotropic nanoparticles display multiple resonance peaks - each usually corresponding with some symmetric axis of the particle. With colloidal synthesis nano-triangles, nanorods, and cubes can be quite reliably produced (and it's quite fun:))). To respond to Hadinos, yes exactly! You can use absorption spectra to estimate both the average size but also the dispersity of your synthesis, if you have a good theoretical model for the size and shape dependent absorption of the nanoparticle! Great Video!

[@4n2earth22]

@@BreakingTaps "it only prints out on thermal paper" and "reaaaaaally old" kinda mean the same thing..... ;-)

[@BreakingTaps]

@@4n2earth22 Hehehe.... I do have a soft spot for thermal paper though, very satisfying :D

[@BreakingTaps]

@@niki40935 Oh, that explains some of the images I saw of rods and "stars" which had really interesting color variations. I guess each dimension of the particle can give rise to a different resonant frequency, which when combined gives you different colors not possible with just the spherical particles alone?

[@KeesHessels]

Man, your channel should have way more subscrtibers...

[@4n2earth22]

Patience, patience. Oh, and tell a lot of peeps....

[@morkovija]

Share the goodness - do your part

[@WaffleStaffel]

Agreed. One of the most underrated channels. I'd say that in due time he'd be big, but he's already a rockstar.

[@notsonominal]

True story (and this is just a mindless comment to feed the beast..:)

[@Tahira204]

Just discovered this channel, super educative, I love it.

[@TeamStevers]

Love your videos! So many subjects and in depth while being digestible. You are the science teacher for the modern age. Production quality is top notch. Get an agent and pitch a show to Netflix. You have that X factor.

[@BreakingTaps]

I think that's the nicest thing anyone has ever said to me! Thanks for watching, and the kind words! ❤

[@TeamStevers]

@@BreakingTaps you deserve it my dude!

[@romit45612]

in my undergrad chem labs we made magnetic nanoparticles to create a ferrofluid, was pretty fun and looks cool too!!

[@NB-ro5vo]

How do you deactivate Nano particles

[@Slimysock-td6oq]

Yo can I get a procedure?

[@maku6087]

Basically it is the same principle as with a resonating dipole antenna. Just on a much smaller scale with much shorter wavelengths.

[@mastershooter64]

man this channel's content is amazing! this guy should have tens of millions of subscribers and views and I don't understand why he does!

[@robbystokoe5161]

I learned an amazing amount from this video. Your explanation of the concept of a plasmon with the wave analogy was fantastic. I'd heard of plasmon resonance before but didn't know what it was until now. This is just the second video of yours I've watched, and I'm excited to keep learning from them.

[@AlsoDave]

On what to do with them: it'd be incredible to see conductive transparent thin films with silver ones, apparently it's a potential alternative to ITO

[@elektronikzmbrtlar1586]

Metal nanoparticles can be a really good chemical catalysts

[@smash5967]

Wait, you're telling me the wave/particle duality thing doesn't apply to the ocean?

[@erbalumkan369]

Any wave needs a medium to pass through.

[@tamasmihaly1]

You're a good teacher. Clear and logical. I look forward to your future work. Thank you very much.

[@DoingItOurselvesOfficial]

I’ve seen red colloidal gold turn that purple colour when the particles start to conglomerate. Usually when contaminated by another mineral or from UV exposure. You should be drinking the Colloidal gold. It’s amazing for your health providing the particles are small enough.

[@donwp]

Interesting video. Thanks. The scattering vs reflecting effect might allow you to create a stained glass window that shows a different scene in daytime vs nighttime. And, maybe even different again as the inside lights are altered in colour.

[@James-ri3fd]

What a good idea!!!

[@squelchstuff]

Great video, and yet another fascinating out of band (youtube) subject. Being able to produce your own nanoparticles inexpensively, besides equipment layout, could be very useful indeed. I was going to suggest using nanoparticles in a fuel cell ion exchange membrane, but then remembered you said you had trouble with platinum and your laser - oh well. My other suggestion is to take a foray into ferro-fluids. There's all kinds of interesting properties to play with there.

[@BreakingTaps]

Yeah it's a shame the platinum didn't really work, I was hoping it would work since Pt is such a great catalyst for all kinds of things. I thought it didnt work at all, but on reviewing the footage you can see a _tiny_ amount ablated, so I guess you could let it run a long time. But heating the solution to boiling becomes a problem (for the bigger batches I ran it in a water bath which helps)

[@lastofthebest5102]

10k for a near IR pulsed laser is not what I would consider "inexpensively". Funny how he forgot to mention that the machine he is using cost more than most peoples cars.

[@CrazyLabs]

I'd like to see lanthanides nanoparticles. Lanthanides have very strange electrons configurations

[@travismiller5548]

When working hot glass, I sometimes "drill" holes with hot tungsten welding electrodes which are "thoriated" and "lanthanated"- alloyed with very small percentages of thorium and lanthanum. Obviously most of the captured vapors are burnt back off the surface of the glass to clean it up once the hole is generated. Tungsten being the main ingredient, the colors are silvery, and a creamy white.

[@bigbear2310]

Perhaps one of the applications can be in molecular gastronomy. Several cultures use gold and silver foil on food. This can be the newest craze.

[@ronaldorme6375]

fascinating. especially the Lazor obliteration technique

[@lostlithium4687]

Till now I only read it in the books, thanks for the demonstration

[@lnaesll]

You are an incredible teacher.

[@avialexander]

That purple doesn't look like any particular wavelength of light, do harmonics of the base frequency also get reflected off the nanoparticles?

[@BreakingTaps]

Good eye :) I glossed over that, mainly because I couldnt get my UV-Vis spectrophotometer working to show the absorbance spectra. As the particles get larger (or start to aggregate) the absorbance starts to red-shift and broaden out. So more longer wavelengths are absorbed and the shorter purple/blues are transmitted. Until you get big enough that it starts behaving like bulk metal gold again. There are charts of the spectra online if you're interested, like this one: cdn.shopify.com/s/files/1/0256/1107/5658/files/gold_nanoparticle_absorbance_93074e71-b7d1-4b6c-bba1-171f028c4d5f.jpg?v=1570803718 E.g. at 20nm, nearly all green is absorbed and half of blue/purple is absorbed, leaving just red. But by time you get to 400nm particles it's a pretty flat profile, transmitting just a bit more blue/purple than red.

[@avialexander]

@@BreakingTaps Ah cool, thanks! So it looks like the harmonics effect exists, but is kind of overshadowed by the statistical distribution of particle size producing a wider spectral response. So the plateaus on the shorter wavelength side of those spectra would be the harmonics, if I am not mistaken?

[@BreakingTaps]

@@avialexander To be honest, I'm not sure! we've reached the edge of my knowledge here, so you probably have a better intuition of the effect than me. From my very loose understanding that sounds pretty reasonable though :)

[@nadimfetaih3841]

I know this video was 2 years ago now. But it would be super cool for you to use the nano particles to create a large version of a QLED tv. Like, make a few pixels that are large enough to see the separation of them, and have them emit light in the same way as a TV does to get a better understanding of QLED technology!

[@Psychx_]

This seems like a super material efficient way to prepare precious metals for use as catalysts.

[@Jandodev]

Lasers, plasmas, gold what else could we ask for!

[@logicalfalse]

Gold nanoparticles are used as a dopant in semiconductors. You could make a DIY LED that uses the nanoparticles as both a dopant and a plasmon colour filter. Great channel!

[@Alexander_Sannikov]

Wow the scanning laser beam looks really futuristic, love it!

[@LanceMcCarthy]

You just blew my mind, plasmon resonance is awesome.

[@neillcoetzer9133]

You should look into cadmium Selenide quantum dots. Doing bachelor's project on it now and it has some very interesting properties and optimization problems in the synthesis. The synthesis itself also isn't particularly difficult, which is nice when you need to do the synthesis like 50 times

[@James-ri3fd]

Interesting

[@georgewashington90]

To improve the video put on the dark rounded plate white piece of paper. It will make deference in colors of your test tubes more visible.

[@gabrielbouvier7763]

How about using your nanoparticles in glaze, for pottery? The results should be stunning!

[@rynther]

This is pretty cool stuff, and in regard to color, relates to dichroic glass, and "diffused" gemstones. Created by surface coating or flash plating glass for dichroic, or diffusion of a compound into the upper one or two molecular layers of a gem to change it's optical properties. A fun and easy to get sample of this is "aqua aura" or "rainbow aura" quartz, produced by flash plating clear quartz with either gold or titanium respectively. (fun fact, if you sand off the coating on one face of an "aqua aura" quartz piece, you can see the red transmission light, instead of the blue reflection.) Diffused stones are much more diverse, as the body material interacts with the surface layer in many different ways, but it's generally used to enhance what would otherwise be uninteresting or less valuable stones. A prime example being iron diffused into aluminum oxide to enhance the blue in white or very pale sapphires. Meanwhile, thanks for the great content, I would love to see if these nano particles could be used for color filters.

[@seanmcelwee5034]

Early pandemic I was watching a series of lectures on nonlinear optics. They mentioned gold has nonlinear properties but due to high absorption, cant be used as thin film layers or bulk material like other nonlinear materials. They instead use solutions of gold nano particles. Might be interesting

[@gaiustesla9324]

just found your channel mate and its bloody good.

[@UnFiltered1776]

Plasmon resonance brought me here, but I stayed for the home-shop and ancient nanomaterials.

[@JayeDiesel]

Figure out a way to add the nanoparticles from any of them and fuse or coat them to another metal. Or add them to some nail polishes to get some crazy effects... so many ideas. A fuel additive, possibly use them in a heat pipe to help move heat better. Or for it to move more heat due to overall density etc... Ok, I'm done. For now... Awesome video. Really felt like I learned something! Thank you!

[@scootergem]

I feel very comfortable with what you tell us, I trust you. Please continue being so forthright . That's very important in science. So many times the facts are contaminated by "facts" that confuse or mislead. The job you are doing is above that and I thank you. Good information isn't always easy to find. 🦉

[@ProtonOne11]

One thing that would interest me about the production process: I guess at some point the suspended particles in the liquid are interacting so much with the laser beam and cavitation that the production of new particles is significantly slowed down. Did you just stop at that point, or did you increase the particle concentration by evaporating parts the solvent. And what happens for example with the red liquid if you completely dry it out? Do you get a red gold powder, or does the color change back to gold at some point?

[@BreakingTaps]

Ah, good question! I wanted to mention that but completely forgot. You're right, at some point the suspended particles start eating up too much of the laser power and production really dies down. I side-stepped that to some degree by ablating the vials on their side, so that there was less liquid in between the laser and metal. But that's the main reason the "continuous flow" setups are preferred for batch production (it also carries away bubbles which helps too). A high NA / short focus lens really helps as well, less laser fluence is lost pre-focus. I mostly stopped once density started to get too high, but also just at the point where I liked the color (which was around 5min for me) so not super scientific :) That said, there's a neat trick you can do once the suspended density gets high enough: you can re-focus the laser "inside" the liquid and start ablating the nanoparticles themselves. I didn't do much rigorous study of it, but some papers claim it helps reduce particle size since you're re-ablating the nanoparticles. The circular motion supposedly helps since it helps swirl larger particles towards the center. I haven't dried enough solution to tell unfortunately (only small amounts for AFM, and that was done on mica which is yellow'ish anyway). But I have read that these particles "red-shift" due to different index of refraction of air vs water, so they would probably skew more/darker red once dried. I don't think they return to a gold coloring unless there is sufficient density to really start agglomerating, and even then it's probably more a dark blue.

[@tedv5379]

Nano particle can be used to create “solar blind” UV-C light passing filters. A solar-blind filter that passes wavelengths less than about 300nm while blocking all visible light and longer wavelength UV-B and UV-A light can be used with various semiconductor detectors view corona discharge, welder flash, detect hot flames and even see non-line of sight scattering of UV-C sources, even in broad daylight. These types of filters are very difficult to fabricate and are quite valuable. I’d love to see some experiments to fabricate one. Thanks for your content.

[@matthewreavley]

I'm trying to recall from my nanomaterials course, but with surface plasmon resonance, the specific resonant frequency that you mentioned absorbs light of that frequency, that light isn't reflected back the direction it came, but rather the energy that's absorbed gets re-emitted in all directions. As a result, the intensity of that colour is reduced when you have a light source shining through it (eg. When the lycurgus cup is red, its because the intensity of the green light travelling in the same direction is now significantly reduced), and in all other directions (like when the light it outside the cup) , you only see the absorbed and emitted colour (green)

[@BreakingTaps]

Ahhhh ok that makes a lot more sense! I admit I spent a _long time_ debating if it was being absorbed or reflected or just elastically scattered or something else. I couldn't find a good layman explanation, and all the papers were mostly over my head. Cheers for the explanation! Will add this to the addendum!

[@omsingharjit]

1;53 wow that's Awesome technique .

[@realcygnus]

👍 We don't need no stinking applications. 🤣

[@moonstreetlabs]

Yay, plasmon resonance

[@chbu7081]

I'm doing that now.

[@johnmanderson2060]

Thanks for the plasmon resonance explanation, it was top notch ! 👍🏻

[@ramous5182]

Awesome! How did the romans get nanoparticles for the lycurgus cup? Did they use a gold salt that was reduced in place?

[@BreakingTaps]

Unknown! :) Apparently there is still a lot of debate how they managed to get the gold-silver alloy in the glass. Some historians think it was accidental contamination from silver/gold work elsewhere in the shop. But other historians discredit that since it's clearly a decorative piece, so they think it was intentional. There are some other broken fragments of glassware that has a similar trait from the same time period iirc. Gold chloride and silver nitrate were commonly used for stained glass in later time periods, so it's entirely possible they knew the same trick and incorporated it. I personally suspect it was a chemical synthesis route like you suggest, rather than physically generating the nanoparticles since they'd also need a way to purify out the larger nanoparticles to get that color.

[@4n2earth22]

They got reallllllly tiny midgets to work on that project, if memory serves....

[@icebluscorpion]

You could do dye lasers too with this with the right material

[@LunaticTheCat]

I used to make gold nanoparticles weekly as an undergrad research assistant (although I used a completely different method than you did).

[@joeshmoe7967]

This video and other on your channel, just go to show there sooooo many things one can learn, but with our short life spans we can't learn them all. Channels like this at least allows us to pick up some crumbs. Great content. - Cheers

[@whitebeard1807]

Learn new thing today! Thank you.

[@WaffleStaffel]

CoeLux artificial skylights are an interesting application of titanium oxide nanoparticles. I wonder if a DIY version could be made with the liquid sandwiched between two sheets of glass. I've made silver nanoparticles in water in varying concentrations. It has a diffuse yellow-greenish tint. At the most concentrated, it looks like antifreeze.

[@BreakingTaps]

Ooh, I like this idea! I remember seeing that artificial skylight made with soapy water (on DIY Perks iirc?), would be cool to replicate the commercial version. I'll start digging around to see if I can find any of their patents or how it workswith TiO2

[@OutOfNamesToChoose]

@@BreakingTaps Yes please! Ever since I saw that DIY Perks video, I'm disappointed not to have seen much more mention of it elsewhere. I'd love to see a nanoparticle commercial version (and who knows? It could turn into a very handy little project!)

[@josephf6785]

This would be a pretty interesting application!

[@WaffleStaffel]

@@BreakingTaps I was unaware of the DIY Perks video, thanks! He did a beautiful job. I believe the relevant patent is USRE47363. They describe a number of processes, but it looks like they're using cast PMMA. In section 20 they describe mixing in the particles, sonicating, then centrifuging the material before casting it. That's a big undertaking. One way or another it would be worth it. I live in the PNW, and it's often times as dark and rainy as the DIY Perks video.

[@BreakingTaps]

@@WaffleStaffel Oh awesome, thanks for digging up that patent! I found some related patents from different companies, but couldn't locate theirs. Just had a skim over the patent, surprisingly accessible and easy to read for a patent! And lots of good background information/explanation... I think I can adapt this. Cheers!

[@EdwardOGrace]

If you super heat the coloured liquids in a microwave oven until the colour disappears and let the liquid evaporate you will be left with monatomics. The colours (Atoms removed from a solid) are indicating that they are still in a colloidal state. Light refraction through colloidal states create colour, Light refraction through monatomic states look clear. The powder of monatomics (ALL) looks the same as baking flour.

[@VincentGroenewold]

Super interesting, you always present things that likely just interest you, but are quite unknown for the general audience (and even me being a former scientist). :) I wish you a million subscribers.

[@VincentGroenewold]

Also, this channels warrants a new Patreon I think, so hi! :)

[@panama_dan]

Regarding what to do with the nanoparticles, maybe cast some in a plastic so you can have an indefinitely suspended sample? Might take a lot of trial and error, but it would be a nice souvenir for the work you have put in. Further, I did some undergrad research in SERS using gold and silver nanoparticles. You could use them as a means for amplifying the signals of analytes that may be too dilute to detect under normal conditions. This requires diving in and setting up a Raman spectrometer (gratings, optics, lasers, detectors) and you seem relatively well equipped for it. Morphology also affects this and could be an interesting exploration in the analytical side of chemistry. Heck, you could just play around with surfactant/capping agent effects on morphology for fun to get rods, stars, cubes, maybe even tubes. Hopefully this will spur some idea for you to pursue that won't be an Sisyphean endeavor!

[@MD-qh6ld]

or have them suspended in molten glass, kind of like the lycurgus cup

[@Graphene_314]

"Probably ghosts" -Ex&F

[@neuroatypical6984]

Two suggestions one of them make nanoparticles of various sizes to reflect a specific frequencies and make a spectroscope that works with ambient light a second suggestion is to ablate magnetite and make a ferrofluid

[@50srefugee]

Shine a bright light through a gold thin film, and you get a greenish-blue spectrum. Easy to see with the plastic laminated gold currency known as gold backs. (The one and five GB denominations work best, since they're the thinnest.) That greenish color is peculiar to gold.

[@Codebreakerblue]

That laser scanning over the surface looks scifi as heck and I love it

[@_vicary]

First time here, KZbin auto-playing in background and I thought this is Cody.

[@minhthuanvo2150]

Interesting! it kinda reminds me of quantum dots

[@philidor9657]

Metallic nanoparticles are to quantum dots as plasmons are to excitons :)

[@minhthuanvo2150]

@@philidor9657 didn't know that before thanks!

[@aimlessweasel]

I was thinking the same. For the application suggestions I was thinking a really low resolution, ridiculously expensive color display. Then have Technology Connections review it...

[@crackedemerald4930]

I wonder what it would happen if you hit a colloid with a laser matching it's resonant color

[@sandorkonya]

divsion by 0.

[@TheLightningStalker]

I'm slightly concerned that the algorithm knows that I am a nanoparticle.

[@ericslighton5813]

Gold chloride added to molten glass reduces to form a colloid of metalic gold particles in solid glass. The result gives the brilliant ruby color in some Venetian glasswork. I guess this is the same phenomenon using ancient tech.

[@justinmillard3595]

“golden wife”; tungsten [W] welding stick melts... + iodine metal [I] [53] + iron [Fe] [26] = gold [79]; red solution [iron or ferrous sulfate]; purple solution [iodine];

[@DIOsNotDead]

imagine having to hide your gold from robbers and when they break in they see a huge glass pitcher of gold nanoparticles but they don't bother because they think it's grape juice and they leave disappointed

[@namenotshown9277]

as a very general rule, waves and other phenomena occur at boundaries eg water/air interface, basically boundaries are very interesting places

[@lukas.brinias]

Well, gold nanoparticles exhibit strong native fluorescence. I've got an excimer and argon-ion laser here if you want to try building a dye laser.

[@omsingharjit]

colour change due to different nano size may be because of nano particles light interaction with different different wavelengths differently like Quantum dots may be

[@JohnDlugosz]

A plasmon is the *quantized* electron density wave. The nature of QM gives you all-or-nothing at any time you look at it; that is why the E-M wave becomes _photons_ . Although it's a collective phenomenon with continuous positions, quantization appears at the smallest scales or when interacting with something that's already quantized. It ends up that you can treat the overall gestalt behavior of the sea of electrons and the atoms holding them together in the same manner as a particle! This sweeps all the messy complex interactions under the rug and gives you a simple model. This is called a *quasiparticle* . It's not surprising in this case: particles in QFT are due to excitations in a quantum field. A sea of electrons behave as a field where you can plot the density of the electrons. So, the same math generally applies.

[@johnmanderson2060]

I wonder if your metallic nanoparticles could be Infused in layers inside aerogel in order to create some useful device, like a catalyst apparatus or a solid state battery ? (my favorite topic, i am an EV fan) i wonder if metallic nanoparticles and electrolyte infused aerogel could be a good battery inner nanomatrix capable to block dendritic formations. Thanks for your great videos. 👍🏻

[@franciscojavierramirezaren4722]

Thanx for sharing, great video! Pauli exclusion is not for free electrons (electrons gas) its only for electrons in atomic or molecular states. 🤔

[@BreakingTaps]

Gah! I was on the fence about that but decided to include it. Time to start an addendum with corrections! Thanks for the note :)

[@franciscojavierramirezaren4722]

@@BreakingTaps Thanx you! Keep doing, great content!!

[@psyneur9182]

The Pauli exclusion principle applies to all fermions: no 2 or more identical fermions can exist in the same quantum state. Atomic/molecular states are just one instance when the principle applies. Although I'm not sure mentioning it was necessary for explaining plasmon resonance.

[@franciscojavierramirezaren4722]

@@psyneur9182 Electron gas is a Boltzman gas at ambient temperature (in fact follows Boltzman distribution) and behave like a clasical gas, so no relevant the fermi exclusion. Collective electrons oscillations are the core explanation of phenomenom.

[@ralfyrules]

Platinum nanoparticles absorb in the sub 400 nm part of the spectrum, which is why you don't see any color with the nanoparticle you created. A neat way to verify would be do heavy run of ablation and weight Pt on a precision analytical balance (must be accurate to 0.1 mg to see any change probably). I also doubt that the NaCl is preventing agglomeration. NPs that start turning shades of reddish black are usually agglomerating. Unagglomerated material just looks normal.

[@ian6083]

This is amazing work! Thank you so much for sharing! Use the particles in suspension in an MHD apparatus. Apparently, even gold can be magnetized under certain conditions. This would be a great science demonstration.

[@BreakingTaps]

Interesting! Added to my list of things to read more about, thanks for the tip!

[@CenturianCornelious]

Questions and suggestions Questions first: 1) Do you have an idea how many atoms are in the resultant microclusters? 2) Have you considered using Aqua regia instead of water or alcohol? Seems like that might break down the suspended material even further. Suggestion: Get the microclusters as small as possible(maybe by exposing to Aqua regia and then rocking the ph repeatedly), then neutralize acidity and feed the suspension to plants. Edit. I suspect the glass cup was made by dissolving gold, evaporating liquids, then melting the resultant powder. That might be another thing to do.

[@TheAruruu]

use suggestion: you know those oil and water moving sculptures you used to find in doctors offices? could you make one of those using the red gold nanoparticles and have it change colors while moving?

[@w__a__l__e]

complete shot in the dark run a current through it, may be there will be different conductivity/ check the resistance of the different nano particle configurations

[@hunnybunnysheavymetalmusic6542]

You MIGHT be able to use these particles, especially since they seem to have more than one light output for a cascading liquid holograph. Especially if you use them both to tune in AND tune out light, you could use them to create shadows, which is particularly difficult in cascading liquid holography.

[@growthisfreedomunitedearth7584]

The silver can be sold. This is essentially what people sell as colloidal silver, possibly even a better product. Gold is also good for the body in small amounts. You may be close to something much grander than you realize.

[@lacheur]

An example of this happening in nature is certain types of agate or chalcedony. Microcrystaline structures sometimes give them a property that they'll appear blueish in reflected light, but more reddish in transmissive light. I have a few "Holly Blue" agates that look blue in normal light, but reddish purple when you shine a light through it. I'll send you a sample if you want.

[@justinmillard3595]

+ hammering of metals for heightwise reduction or height and waistwise reduction to “snap” gold into itself...

[@angiasaa]

I think you should have done Titanium nanoparticles in water anyway. Titanium dioxide is incredibly white and is used to make white paint.. I'm not sure how nanoparticles of Titanium would mess with light reflecting or passing through, but even if it's just white, I'm sure it would be rather cool to watch little white puffs being dissipated into the liquid.

[@omsingharjit]

if the colour is mix of two phenomenon resonance and Scattering .than it will be nice to do little experiment with it like shining perticular wavelengths of light one by one to see which one Is Reflected best vs other absorbed . shining with higher wavelengths blue or uv to see how much scattering occurred

[@dantesmith3664]

great video. I really enjoyed it

[@hullinstruments]

Not sure if you’re in the market for more laser stuff, but Thought this might interest you….. I spend a most of my Hobby funds on lasers and optics equipment. After a few years messing around and buying a lot of old decommissioned the military and medical stuff… I learned The best bang for your buck are the coherent “fap800” modules. Which come in 40watt and 80 Watt of optical output power in IR/NearIR Fiber laser modules. They pop up on eBay for under $100… Maybe a bit more if you’re buying from an experienced laser dealer that has tested the module under load. That’s 40 or 80 Watts of optical output power. And of course they can be used and combined together for all types of great projects! I have purchased over a dozen of them the past few years for different projects.… repairing stuff for customers, Building combined arrays, and for custom builds/rebuilds of DPSS laser units. It’s an incredible price for that type of power that’s already in a nice and well made package with built-in terminals and TEC temp control. Far cheaper than the Jenoptik brand 40watt modules i was using. Which are $300 to $500 even when used.. And anything made by “coherent“ company is incredibly well-made. Buying them in these modules about the same cost as the High powered C-mount diodes or laser bars by themselves.… but I already coupled into 19 individual fibers necked down into a single combined output. With perfectly cleaved and prepared fiber ends. most of the modules are hermetically sealed, with an inert gas, so you don’t have to worry about moisture, contamination, and stuff like that. so if you don’t need to get in there and do a bunch of customizing they make a perfect pump module in a DPSS project or other various needs. And if you do open them up, they are still perfectly operation of all and rugged.

[@BreakingTaps]

Oh, neat! I'll keep an eye out for one! Not sure what I'd use them for as of yet, but I like to collect/hoard interesting optical equipment because you tend to find cool uses for them later. Cheers for the tip!

[@_Reverse_Flash]

Man I hate it too when my plasma reactor starts to fail in the middle of a home movie.

[@kreynolds1123]

Maybe a bit beyond DIW, but maybe nano particles applied to the surface of silicon might be made to act like a field effect transistor that works at the freqency of a laser shown on it.

[@meferswift]

I do this when im students. My prof would pay me to "watch over" The process, as the machine is pretty much automatic. Just had to pour new water into it.

[@travismiller5548]

It would be neat to see what ti pen looks like on glass under a microscope. Titanium can be used to mark glass and artists us it to sign glassware. I've had mixed results creating a conductive path and electroplating it. Had to use a conductive paint to bridge to the fine titanium lines and bring it into the plating circuit. What I found was copper would plate the line, then loose adhesion to the titanium and lift up on one end of the line, and the process would begin again, creating a series of fractal-like curled fingers.

[@drd4059]

Nano particles are useful for spectroscopy of biological molecules. The plasmon resonance can be used to enhance the signal from particular molecular transitions by factors of up to 1000.