One of the cool things about this stuff is that it's much more resilient than regular fluorescence materials. I've had samples last for a year and still remain bright.
Not gonna lie, I've been looking forward to this video for a long time. I was going to attempt this myself but I decided that my lab isn't yet at the stage where this is feasible. I'll be making other nano particles to add to my collection, but these are still out of reach for the time being. Thanks for the awesome video. Even though it's not something the home chemist can really do (mostly due to the danger level), it's still a beautiful synthesis.
you should do this experiment again, but do the whole final reaction under the UV light so that the camera can show the color changing as the particles get bigger.
The solutions are very stable and only start to break down if you heat them beyond a hundred degrees celsius. So there is no need to further stabilize them. I think for most applications a continous spectrum is unwanted, a discrete narrow distribution is preferred. but if you really want a continous version then i'm sure you could make them with continous tapping as you suggest.
alright, sorry, i've had a bad week. :) thanks for understanding. My point still stands though, while this may not be accessible to most people, i'll still teach it because i aim to educate, enable, and inspire. It's the few people that can do this and improve upon it that drive us forward. And it's the rest of us that understand and appreciate this work that we get out of their way and support them to make it possible. Q-dot based imaging agents are not far off, i hope you use them ^_^
The magnetic stir bar can tolerate up to 300 celsius. The heating required in this video isn't very high. Only about 80 celsius. so its well within the range of the stir bar.
nah, it just turns a reddish/yellow crud. But the important part of quantum dots is that they are specific and controllable. This makes them useful for displays where we can engineer a pixel to give us exactly the color we want. Mixing them and making them uniform defeats that purpose.
It doesn't work that way, it's not the temperature that determines their size, its the time they stay at 200 celsius. Pre-setting different temperatures will not give the results you want.
to explain that fully would take hours of video. The short and grossly simplified explanation is that the part of those devices where the electrons make photons or the photons move electrons is where the quantum dots are used.
The reaction only continues above two hundred degrees. At room temperature or even at a warm 60 celsius, nothing will happen. as for the next question: Quantum dots can be engineered to dissolve in most liquids, from water to hexane.
Out of all the chemistry channels I watch, your videos are consistenly one of the highest quality, and everything is explained clearly, and in an interesting way. I hope you keep making these videos, I look forward to each one!
not exactly, the camera basically autoranges the spectrum, so it exaggerates the differences between each color. With infrared though its actually seeing something new.
I think Q-dots are making inroads into molecular diagnostics, faster FDA approval there since it's not being applied to a live person, just their blood/serum/stool/CSF samples. My buddies in analytical chemistry showed me a new Q-dot based ELISA (QDLISA?) test they developed. So it's getting there. As for NMR, i hear talk of using fluorine based contrast agents and performing F19 MRI, following the contrast as it bound to tumors and stuff. Not sure how far that's gone yet.
While the creation of the of the triphenylphosphine selenide and cadmium oleate are trivial and can be easily looked up, the problem comes in presenting the Quantum dot formation reaction. Turns out the impurities in the phosphine (trace amounts of dioctylphosphine) pay a crucial factor in making the reaction work. Unfortunately that reaction is so complicated to explain that the length of the video would double if i tried to do so. If you want to read more, check out the reference i posted.
I find it very fascinating that you have to use a camera to see the varying array of colors. It's cool to see how one form of science (that being camera technology) can help you in another somewhat unrelated from of science (that being chemistry).
I absolutely love these kinds of videos. Simple, easy to follow reactions that don't take a long time and result in a useful product. I'm going to use this to make a glass lamp. I'll react a fairly large amount and fill a glass lamp with it, then put a UV bulb in it . Thank you NurdRage.
I'm working in a fumehood so all the smells are sucked away. But anyway, these chemicals are not volatile enough to have a smell, so it's not an issue. Also i don't let selenium get on me or in me, that's just bad safety.
Yes you're right. I'm just lucky to have pure Se as well as NaBH4 and N2 line, but it took me several years to build the lab as it is now and even though i'm not as nearly well equipped as the professional ones I think I can preform the synthesis and I'm looking forward to it. Just for the record, I think that well motivated amateur can preform nearly any synthesis it's only matter of determination and resources.
nope not toxic, unless you lock yourself in a sealed room so that the carbon dioxide asphyxiates you... then again, locking yourself in a sealed room will asphyxiate you anyway just slower. So the experiment is pretty much safe.
The equations for this particular reaction are very complicated and not entirely understood. Turns out the impurities in the chemicals actually play an important role and produce their own set of reactions. I omitted them to keep the video simple.
I am an amateur chemist from Hong Kong. I have had successes in making gold nanoparticles about 5nm in side. The reason I want you to replicate the experiment is that I have noticed that the nanoparticles have magnetic properties and I am not sure it was by chance. I dissolved 4 pieces of pure gold foil (4cm*4cm) into aqua regia. boiled down the mixture to AuCl3. the aucl3 is made to a 10ml solution. 3ml of aucl3 and 20ml of 25µmol dm-3 sodium citrate at 80C under vigorous stirring for 20 min.
Then as a person with a high degree of education in a natural science field you of all people should know that alot of things in science are inacessible to the average person. Are biochemists tools of thermocyclers and PCR reagents available at the supermarket? Please point out where i said you weren't an experienced chemist. And if you wanted practical applications i gave you three examples right in the video. As a physician don't you want MORE medical imaging techinques available to you?
I have these chemicals on hand, and so do many other scientists. But before you get snarky please realize that this this video is for educational purposes. I'm sure most people in the world don't have the materials on hand to build cars either, but we still teach engineering in schools. In fact, on youtube, you can find large numbers of videos on building cars. Point out where i am required to make videos helpful to *you* specifically.
The thin layer would actually lower its thermal resistance, it was a cost reduction. If it is being researched, chances are they are pretty stable. In the video, you see that very little of the solution can still produce a significant glow. Having an 1/8" spacing between the outer glass and the inner wall should suffice for retaining a high level of emission. As for the wavelength, that is determined by the size of the dots, not the density in the suspension or the amount used.
but above 220 you destroy the dots. Once again, setting different temperatures will not give better results than simply withdrawing the solution at different times
not really, for that you need a good fluorescence spectrometer, i haven't built one yet. Someday i'll get around to it. I think they're very broad though, i didn't exactly quench the reaction in the most efficient way possible :)
Your videos are absolutely fascinating, not to mention perfectly explained. Awesome work; keep it up! Being a seventeen-year-old girl and a part of the generation mostly comprised of complete idiocy, intelligent videos and whatnot are pretty scarce these days. So in short, thank you, good sir!
Commercial quantum dots for consumer products will probably be made of something else. I'm using CdSe here because it's really easy to make quantum dots with them. So don't worry, i'm pretty sure some future badass Quantum Dot TV or computer monitor will be made of safer materials. :)
More accurately it's an engineered fluorescence effect. The electrons are being excited but they are not leaving the quantum dot, so it's not photoelectric.
This is a really nice demonstration experiment. Are you sure the camera's sensitivity is the key to the increased color differentiation? It might be due to the UV light messing up with the sensor. Try taking a photograph with an UV filter, there might be a noticeable difference.
Actually, trioctylphosphine is very heavy and doesn't volatlize, so it has no smell. Neither does its selenide version. Granted i never sniff my chemicals and i always work in a fumehood when handling anything dangerous, so i'm not 100% sure. :) That being said, since i am using a fumehood, my lab has no smell from this. ;)
Good point on using UV LEDs and a thin layer for heat control. The shelf life is still a question though since in the video he mentions only that this is being researched for its possibilities in the use of... So, it isn't in mass production yet. The thin layer in the double wall scenario brings up the additional points of how dense the particle layer has to be to fluoresce properly, and if a thinner layer will still produce the same wavelength. Such as the perceived brightness of the amounts.
just....F-A-N-T-A-S-T-I-C !!! I am really surprised, what the field of chemistry still has to offer. There is really no end visible in the complexity of nature. How stable is this solution ? Can you stabilize the state of the quantum dots, so that it becomes inert to wide ranges of temperature fluctuations ? If you would use a heated (or insulated) dripping funnel could you theoretically make a more continuous spectrum of quantum dots ? Really excellent. Maybe I should study chemistry...
At the end i was talking about fluorscence emission. You can clearly see at 2:07 we're looking at absorption, not emission. You can see right in the video what the final color of the solution is. clear.
its basically a shaped magnet that you place into the beaker or flask that is on the stir plate or hot plate. there is also a magnet underneath the actual stir plate surface that spins and grabs hold of the stir bars magnetic field, and as the stir plate's magnet is spinning it causes the stir bar to spin also.
I see. Thank you. Now, I would like to ask you a few more things: 1) You used selenium - can sulphur be used instead? 2) Could any other metal used instead of cadmium? 3) Which other chemicals act like this? Which can form quantum dots? Do all chemical in some ways act like this? 4) Is it necessary to use organic chemicals? How about Na2Se + CdCl2? Would not it do in non-concetrated solution just the same effect? Thank you very much.
interesting, i learn something new everyday :) I'll see what i can do about the filters, i don't have one on hand but i'll keep it in mind next time i'm out ;)
I used to, but i got pissed off when most of my students copied answers. Worse of all they copied the WRONG answers, they didn't even bother checking if they were right.
1) yes u can. instead of CdSe, ull get CdS. u wont be able to get this huge range of colours though. 2) Zn can be used. can make ZnSe or ZnS. 3) these are semiconductors, typically called II-VI semiconductors. typically the ones used are CdS, CdSe, ZnS. u can get InP, GaAs as well, which are called III-V semiconductors 4) high chance u will get precipitation instead of nanocrystal formation. u would need a reverse micellar rxn system. hope i got the info correct =/
This video isn't for amateurs, i clearly say its for experienced chemists. But anyway, sodium borohydride, pure selenium, and a good N2 capable lab seem just as out of reach for the amateur as the classic preparation.
You know your right. Despite being an accomplished chemist and working in a lab all day. At home nurdrage must make crack to sell on the streets. It all makes sense now! Thank you for the enlightenment. Its not like he has 100 videos showing various scientific experiments.
There are another thinks I would like to ask you: 1) What exactly happens to the triphenylphosphine and the oleate molecules? We know it forms CdSe, but what happens with the rest of those molecules? 2) Can I use cadmium acetate or cadmium chloride without a big change of result? 3) What is the smallest and the largest size this particles can reach? 4) Can I use triphenylphospine instead of trioctylphosphine, and then use e.g. benzene as a solvent, if necessary? I need your answers. Thank you.
Try some transition metal chemistry. These compounds often have very nice colours due to the fact that they have electrons able to move to higher energy states, and many very nice reactions can be performed using them reasonably safely.
Made silver nanoparticles, and had them grow to different sizes by using different amounts of KBr to limit growth of different samples. The solutions were all different colors, and you can calculate the radius of the particle with spectroscopic data
The top three questions i get: 1. How to make bombs. 2. How to make drugs 3. How to answer problem X (basically they want me to do their chem homework for them) I don't have the time, nor am i paid enough to help people break the law or avoid learning things for themselves.
I did almost this exact experiment in my second year university nanoscience class. We then used flourescence spectroscopy to examine them. Really cool experiment. I added the trioctylphosphine too quickly to the selenide solution and it exploded so we lost most of the sample.
Awesome! Thanks. One last question. Why don't you have your own chatroom or something? I mean, I know you probably don't have time, but it would be really cool if you had an IRC channel to help people and answer chemistry questions :)
Turns out. there are more compounds known to science than there are words in the english language. A great deal of compounds out there i don't know either :)
difference in temperatures can be used to increase the amount of time they stay above 200 celsius.this is like that hotter objects remain hotter for a longer time
Selenium, my favourite element. Try making iron, copper, molybdenum or lead selenide nanoparticles/quantum dots they all have interesting electrochemical properties.
No worries! I do often sound "snarky". I don't think the FDA has quite yet approved quantum dot imaging :( unfortunately the gov't has all these "strict" regulations. Keep up the good work...much appreciated..your channel always brings back fond memories of O-Chem and P-Chem labs...the "good" old days! PET imaging is my thing. Wonder what life would be like if MRI (nuclearMR..sounds too scary for people...but it's the same principle) was based on something other than the dipole moment of H2O :)
Thanks again for your uploads always interesting .... Pity some people are so rude in their manner of questions, anyway keep up the postings and work as its greatly appreciated
I'm a biochem major and I stink at organic chemistry even though I really find it interesting. Your demos can be just as valuable as Khan Academy at teaching because they remind me why I like this stuff to begin with.
hmmm.. i don't have sufficiently sensitive magnetic measurement and testing equipment to properly characterize the magnetic properties of nanoparticles. But i'll see what i can do.
I think we are actually agreeing in parallel. :) The thin layer would have the additional insulation of glass + air gap, and by using LEDs, the heat issue would be negligible. Not sure about the quality of the glow or the wavelength since what we are seeing is due in a large part to the color correction of the camera. How much is the question. Also, the vials with less solution appear dimmer, so if you had a 1/8" layer, you might have to optimize crystal size for highest lumen potential.
Because it is a particle in suspension rather than a dissolved fluorescent solution, I would imagine it to have an indefinite shelf life. He did mention it is being used in digital displays, after all. As for the heat issue, if you use UV LED's in the base or a CFL on the top, the heat of the glass would never approach the reaction temperature. Lastly, you would want to have a double layer wall with only a small separation where this would go. Filling it like a lava lamp would be just be stupid.
That was really cool, wayyy over my head, but enjoyable regardless haha. My chemistry experience ends with high school chemistry, but I still find it interesting and fun to watch :)
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One of the cool things about this stuff is that it's much more resilient than regular fluorescence materials. I've had samples last for a year and still remain bright.
Not gonna lie, I've been looking forward to this video for a long time. I was going to attempt this myself but I decided that my lab isn't yet at the stage where this is feasible. I'll be making other nano particles to add to my collection, but these are still out of reach for the time being. Thanks for the awesome video. Even though it's not something the home chemist can really do (mostly due to the danger level), it's still a beautiful synthesis.
Is your lab big enough for this now? ;)
you should do this experiment again, but do the whole final reaction under the UV light so that the camera can show the color changing as the particles get bigger.
Cool idea
the mark of the beast is coming! jesus loves you! dont do it!
The solutions are very stable and only start to break down if you heat them beyond a hundred degrees celsius. So there is no need to further stabilize them.
I think for most applications a continous spectrum is unwanted, a discrete narrow distribution is preferred. but if you really want a continous version then i'm sure you could make them with continous tapping as you suggest.
alright, sorry, i've had a bad week. :) thanks for understanding.
My point still stands though, while this may not be accessible to most people, i'll still teach it because i aim to educate, enable, and inspire. It's the few people that can do this and improve upon it that drive us forward. And it's the rest of us that understand and appreciate this work that we get out of their way and support them to make it possible.
Q-dot based imaging agents are not far off, i hope you use them ^_^
The magnetic stir bar can tolerate up to 300 celsius. The heating required in this video isn't very high. Only about 80 celsius. so its well within the range of the stir bar.
at room temperature the reaction stops and the oleic acid surrounds the particles like a coating and prevents them from aggregating.
nah, it just turns a reddish/yellow crud.
But the important part of quantum dots is that they are specific and controllable. This makes them useful for displays where we can engineer a pixel to give us exactly the color we want. Mixing them and making them uniform defeats that purpose.
No it's perfectly fine and even encouraged, you are what we call: "the future"
It doesn't work that way, it's not the temperature that determines their size, its the time they stay at 200 celsius. Pre-setting different temperatures will not give the results you want.
to explain that fully would take hours of video. The short and grossly simplified explanation is that the part of those devices where the electrons make photons or the photons move electrons is where the quantum dots are used.
That's a very good question actually. I personally don't know of any Raman spectroscopy performed on the dots. If you ever find out let me know :)
The reaction only continues above two hundred degrees. At room temperature or even at a warm 60 celsius, nothing will happen.
as for the next question: Quantum dots can be engineered to dissolve in most liquids, from water to hexane.
Out of all the chemistry channels I watch, your videos are consistenly one of the highest quality, and everything is explained clearly, and in an interesting way. I hope you keep making these videos, I look forward to each one!
not exactly, the camera basically autoranges the spectrum, so it exaggerates the differences between each color. With infrared though its actually seeing something new.
NurdRage Im curious, What would be the most complex experiment you have done? And have you made a video on it ?
Cheers for the videos.
I think Q-dots are making inroads into molecular diagnostics, faster FDA approval there since it's not being applied to a live person, just their blood/serum/stool/CSF samples. My buddies in analytical chemistry showed me a new Q-dot based ELISA (QDLISA?) test they developed. So it's getting there.
As for NMR, i hear talk of using fluorine based contrast agents and performing F19 MRI, following the contrast as it bound to tumors and stuff. Not sure how far that's gone yet.
While the creation of the of the triphenylphosphine selenide and cadmium oleate are trivial and can be easily looked up, the problem comes in presenting the Quantum dot formation reaction. Turns out the impurities in the phosphine (trace amounts of dioctylphosphine) pay a crucial factor in making the reaction work. Unfortunately that reaction is so complicated to explain that the length of the video would double if i tried to do so. If you want to read more, check out the reference i posted.
I find it very fascinating that you have to use a camera to see the varying array of colors. It's cool to see how one form of science (that being camera technology) can help you in another somewhat unrelated from of science (that being chemistry).
I absolutely love these kinds of videos. Simple, easy to follow reactions that don't take a long time and result in a useful product. I'm going to use this to make a glass lamp. I'll react a fairly large amount and fill a glass lamp with it, then put a UV bulb in it . Thank you NurdRage.
I'm working in a fumehood so all the smells are sucked away.
But anyway, these chemicals are not volatile enough to have a smell, so it's not an issue.
Also i don't let selenium get on me or in me, that's just bad safety.
Yes you're right. I'm just lucky to have pure Se as well as NaBH4 and N2 line, but it took me several years to build the lab as it is now and even though i'm not as nearly well equipped as the professional ones I think I can preform the synthesis and I'm looking forward to it.
Just for the record, I think that well motivated amateur can preform nearly any synthesis it's only matter of determination and resources.
nope not toxic, unless you lock yourself in a sealed room so that the carbon dioxide asphyxiates you... then again, locking yourself in a sealed room will asphyxiate you anyway just slower.
So the experiment is pretty much safe.
The equations for this particular reaction are very complicated and not entirely understood. Turns out the impurities in the chemicals actually play an important role and produce their own set of reactions. I omitted them to keep the video simple.
Every time someone says you are wrong, you end up being right. YOU ARE AMAZING!!!!
Hey, this was a great video. The safety warnings, basic theory, actual experimentation, analogy and citation are all done excellently.
So what? The last 15 minute video i uploaded costs $2k to make and made only $100 in revenue. I am NOT wasting that much money again.
I am an amateur chemist from Hong Kong. I have had successes in making gold nanoparticles about 5nm in side. The reason I want you to replicate the experiment is that I have noticed that the nanoparticles have magnetic properties and I am not sure it was by chance. I dissolved 4 pieces of pure gold foil (4cm*4cm) into aqua regia. boiled down the mixture to AuCl3. the aucl3 is made to a 10ml solution. 3ml of aucl3 and 20ml of 25µmol dm-3 sodium citrate at 80C under vigorous stirring for 20 min.
Then as a person with a high degree of education in a natural science field you of all people should know that alot of things in science are inacessible to the average person. Are biochemists tools of thermocyclers and PCR reagents available at the supermarket?
Please point out where i said you weren't an experienced chemist.
And if you wanted practical applications i gave you three examples right in the video.
As a physician don't you want MORE medical imaging techinques available to you?
I have these chemicals on hand, and so do many other scientists.
But before you get snarky please realize that this this video is for educational purposes. I'm sure most people in the world don't have the materials on hand to build cars either, but we still teach engineering in schools. In fact, on youtube, you can find large numbers of videos on building cars.
Point out where i am required to make videos helpful to *you* specifically.
The thin layer would actually lower its thermal resistance, it was a cost reduction. If it is being researched, chances are they are pretty stable. In the video, you see that very little of the solution can still produce a significant glow. Having an 1/8" spacing between the outer glass and the inner wall should suffice for retaining a high level of emission. As for the wavelength, that is determined by the size of the dots, not the density in the suspension or the amount used.
Just took the AP chemistry test. Your videos actually helped me answer one of the questions THANK YOU!
Love your videos, I've shown them to my org chem prof and she can't get enough of your videos.
its sometimes labelled as paint thinner
but above 220 you destroy the dots. Once again, setting different temperatures will not give better results than simply withdrawing the solution at different times
I'm not sure, i don't think so since the dots can't reach that range.
Im not even a amateur chemist or scientist yet I find these videos enlightening.
not really, for that you need a good fluorescence spectrometer, i haven't built one yet. Someday i'll get around to it.
I think they're very broad though, i didn't exactly quench the reaction in the most efficient way possible :)
Your videos are absolutely fascinating, not to mention perfectly explained. Awesome work; keep it up! Being a seventeen-year-old girl and a part of the generation mostly comprised of complete idiocy, intelligent videos and whatnot are pretty scarce these days. So in short, thank you, good sir!
This is, by far, the most impressive chemical experiment nurdrage ever made.
Commercial quantum dots for consumer products will probably be made of something else. I'm using CdSe here because it's really easy to make quantum dots with them.
So don't worry, i'm pretty sure some future badass Quantum Dot TV or computer monitor will be made of safer materials. :)
More accurately it's an engineered fluorescence effect. The electrons are being excited but they are not leaving the quantum dot, so it's not photoelectric.
That just blows my brains away, this is why the world needs more science oriented minds.
i've watched all of the videos you have made, i have never done any of these experiments or ever plan too, but i think its cool to watch.
your welcome, let me know how the other particles turn out
This is a really nice demonstration experiment.
Are you sure the camera's sensitivity is the key to the increased color differentiation? It might be due to the UV light messing up with the sensor.
Try taking a photograph with an UV filter, there might be a noticeable difference.
Actually, trioctylphosphine is very heavy and doesn't volatlize, so it has no smell. Neither does its selenide version.
Granted i never sniff my chemicals and i always work in a fumehood when handling anything dangerous, so i'm not 100% sure. :)
That being said, since i am using a fumehood, my lab has no smell from this. ;)
I never have any idea what you say but i watch your videos anyway because it makes me feel smart
Good point on using UV LEDs and a thin layer for heat control. The shelf life is still a question though since in the video he mentions only that this is being researched for its possibilities in the use of... So, it isn't in mass production yet.
The thin layer in the double wall scenario brings up the additional points of how dense the particle layer has to be to fluoresce properly, and if a thinner layer will still produce the same wavelength. Such as the perceived brightness of the amounts.
I love the way that nor heat, nor cold at extreme temperatures affects the glass beakers and test tubes... Glass FOR THE WIN
Those are chemical burns, they can't be removed, the table fumehood floor must be replaced.
Really interesting. Could the camera be picking up some kind of infrared light as well to end up changing the color more drastically?
in theory you could, but that would be useless for most applications. Its the discrete and highly controlled nature that makes them useful :)
just....F-A-N-T-A-S-T-I-C !!! I am really surprised, what the field of chemistry still has to offer. There is really no end visible in the complexity of nature.
How stable is this solution ? Can you stabilize the state of the quantum dots, so that it becomes inert to wide ranges of temperature fluctuations ?
If you would use a heated (or insulated) dripping funnel could you theoretically make a more continuous spectrum of quantum dots ?
Really excellent. Maybe I should study chemistry...
At the end i was talking about fluorscence emission. You can clearly see at 2:07 we're looking at absorption, not emission.
You can see right in the video what the final color of the solution is. clear.
its basically a shaped magnet that you place into the beaker or flask that is on the stir plate or hot plate. there is also a magnet underneath the actual stir plate surface that spins and grabs hold of the stir bars magnetic field, and as the stir plate's magnet is spinning it causes the stir bar to spin also.
You have given me an idea, maybe i should show how to make a basic homemade fluorescence spectrometer.
I see. Thank you.
Now, I would like to ask you a few more things:
1) You used selenium - can sulphur be used instead?
2) Could any other metal used instead of cadmium?
3) Which other chemicals act like this? Which can form quantum dots? Do all chemical in some ways act like this?
4) Is it necessary to use organic chemicals? How about Na2Se + CdCl2? Would not it do in non-concetrated solution just the same effect?
Thank you very much.
I can comprehend what is being said but reproduce it I cannot. This guy does some neat stuff for sure.
I have done some of this experiments like the nitric and sulfuric acid and the galium one. I love this channel;
interesting, i learn something new everyday :)
I'll see what i can do about the filters, i don't have one on hand but i'll keep it in mind next time i'm out ;)
these particular ones probably not. but there are LOTS of other varieties out there, i'm one exists that has properties needed :)
I used to, but i got pissed off when most of my students copied answers.
Worse of all they copied the WRONG answers, they didn't even bother checking if they were right.
Why can't I like this video more than once? it deserves it!
1) yes u can. instead of CdSe, ull get CdS. u wont be able to get this huge range of colours though.
2) Zn can be used. can make ZnSe or ZnS.
3) these are semiconductors, typically called II-VI semiconductors. typically the ones used are CdS, CdSe, ZnS. u can get InP, GaAs as well, which are called III-V semiconductors
4) high chance u will get precipitation instead of nanocrystal formation. u would need a reverse micellar rxn system.
hope i got the info correct =/
I remember reading about this in science news march 1997 edition and I found it more interesting demonstrated by you.
This video isn't for amateurs, i clearly say its for experienced chemists.
But anyway, sodium borohydride, pure selenium, and a good N2 capable lab seem just as out of reach for the amateur as the classic preparation.
the vials are already cooled, so yes they are the same colors :)
This is truly fascinating, it's one of the thousands of reasons I chose to do a chemistry degree.
1. solvent
2. Answer at 2:57
3. its not purple, its red, but the camera's color balance was a bit off
4. nothing
5. nothing
Just letting you know that your vids have gotten me fascinated with chemistry.
You know your right. Despite being an accomplished chemist and working in a lab all day. At home nurdrage must make crack to sell on the streets. It all makes sense now! Thank you for the enlightenment. Its not like he has 100 videos showing various scientific experiments.
There are another thinks I would like to ask you:
1) What exactly happens to the triphenylphosphine and the oleate molecules? We know it forms CdSe, but what happens with the rest of those molecules?
2) Can I use cadmium acetate or cadmium chloride without a big change of result?
3) What is the smallest and the largest size this particles can reach?
4) Can I use triphenylphospine instead of trioctylphosphine, and then use e.g. benzene as a solvent, if necessary?
I need your answers. Thank you.
Try some transition metal chemistry. These compounds often have very nice colours due to the fact that they have electrons able to move to higher energy states, and many very nice reactions can be performed using them reasonably safely.
Stellar Nucleosynthesis is beyond my capability, i'm pretty sure it always will be.
Made silver nanoparticles, and had them grow to different sizes by using different amounts of KBr to limit growth of different samples. The solutions were all different colors, and you can calculate the radius of the particle with spectroscopic data
nope, those are actual names of compounds.
I personally have no interest in being a chemist, however being the curious person I am, I love to learn new things. Thanks @NurdRage :)
The top three questions i get:
1. How to make bombs.
2. How to make drugs
3. How to answer problem X (basically they want me to do their chem homework for them)
I don't have the time, nor am i paid enough to help people break the law or avoid learning things for themselves.
I did almost this exact experiment in my second year university nanoscience class. We then used flourescence spectroscopy to examine them. Really cool experiment. I added the trioctylphosphine too quickly to the selenide solution and it exploded so we lost most of the sample.
Uhm am I the only one who find out that this video works so damn well for me even in 2022? Thank you so much Sir🥺❤️
A decade ago... "You'll see this in everyday life"
Now look at the electronics section at Wally world
its not the file size that's an issue, just that no one will sit through 30 minutes of boredom.
Awesome! Thanks. One last question. Why don't you have your own chatroom or something? I mean, I know you probably don't have time, but it would be really cool if you had an IRC channel to help people and answer chemistry questions :)
Turns out. there are more compounds known to science than there are words in the english language. A great deal of compounds out there i don't know either :)
difference in temperatures can be used to increase the amount of time they stay above 200 celsius.this is like that hotter objects remain hotter for a longer time
Selenium, my favourite element. Try making iron, copper, molybdenum or lead selenide nanoparticles/quantum dots they all have interesting electrochemical properties.
Goddamn, you were quick pullin out lots of different particle sizes.
No worries! I do often sound "snarky". I don't think the FDA has quite yet approved quantum dot imaging :( unfortunately the gov't has all these "strict" regulations. Keep up the good work...much appreciated..your channel always brings back fond memories of O-Chem and P-Chem labs...the "good" old days! PET imaging is my thing. Wonder what life would be like if MRI (nuclearMR..sounds too scary for people...but it's the same principle) was based on something other than the dipole moment of H2O :)
Thanks again for your uploads always interesting .... Pity some people are so rude in their manner of questions, anyway keep up the postings and work as its greatly appreciated
Awesome experiment. Have you tried doing the reaction under UV light to see the color change in real-time?
I do understand what you are saying in your vids but they are still awesome. Good work.
I'm a biochem major and I stink at organic chemistry even though I really find it interesting. Your demos can be just as valuable as Khan Academy at teaching because they remind me why I like this stuff to begin with.
there are some videos with my "real voice"? alright then, you don't need me to do a video, you can just watch those ones.
hmmm.. i don't have sufficiently sensitive magnetic measurement and testing equipment to properly characterize the magnetic properties of nanoparticles. But i'll see what i can do.
go to my later video of gum in potassium chlorate. it's more suited to those that prefer simpler chemistry as opposed to nanochemistry.
I think we are actually agreeing in parallel. :) The thin layer would have the additional insulation of glass + air gap, and by using LEDs, the heat issue would be negligible.
Not sure about the quality of the glow or the wavelength since what we are seeing is due in a large part to the color correction of the camera. How much is the question. Also, the vials with less solution appear dimmer, so if you had a 1/8" layer, you might have to optimize crystal size for highest lumen potential.
Because it is a particle in suspension rather than a dissolved fluorescent solution, I would imagine it to have an indefinite shelf life. He did mention it is being used in digital displays, after all. As for the heat issue, if you use UV LED's in the base or a CFL on the top, the heat of the glass would never approach the reaction temperature. Lastly, you would want to have a double layer wall with only a small separation where this would go. Filling it like a lava lamp would be just be stupid.
That was really cool, wayyy over my head, but enjoyable regardless haha. My chemistry experience ends with high school chemistry, but I still find it interesting and fun to watch :)
Chemical Engineer here, Like your vids keep it up! :D