 Think that works Okay, I think you guys can see the presentation. So just let me know if you can't let me Put my laser pointer, okay, so I'm gonna kind of restart this timer and we'll see how long it goes So inductively coupled plasma optical emission spectroscopy. It's type of spectroscopy that measures the concentration of atomic Samples through a line emission spectroscopy. So essentially we're giving these atoms energy and they're emitting characterizes character, I Characteristic wavelengths and we can measure those intensity wavelengths and to to calculate the concentration of that sample this technique requires Some standard references in order to build up a baseline of concentrations that we can use to calculate our unknown concentration and also the samples must be dissolved in water either through and like a They must either be soluble in water or you can make an acid Solution to dissolve your sample. So this is a picture of the ICP OES in the chemistry department So it's this big machine here. The user doesn't do anything really with the machine All the user has to do is place their samples in this low robotic arm program the computer and no omically and Deliver the samples for you. So briefly. This is how it works You have your samples that get sucked up with a pump but get put into something called nebulizer which turns your sample into an aerosol mixed with argon gas and then there is a plasma torch made with the RF power supply and the argon gas and Your samples get sent into the plasma and then that gives them energy to admit the characteristic light And that light is measured and separated with a prism And so if you're looking for a particular element, you're just looking at one single wavelength that is emitted from that element and you measure The intensity of that of that light So for just another example, you know for this example, you're looking at lead atoms in your solution and you've picked out a Particular wavelength that we're looking at And you have a calibration sample So a known concentration that you have to measure and then a blank for example So we have two data points on our plot that should give us a line And then you measure your sample intensity and then where does that fall on on that line? And you can calculate the concentration of lead for example in that sample So this is an article I found it's from the journal cult the journal of food composition and analysis the title optimization of Pre-concentration procedure using magnetic nanoparticles for determination of manganese and cereal samples so the idea behind this is that you know cereal samples such as a flour barley and rice for example, they contain a bit of manganese that they get from the environment manganese is a is a In higher concentrations can be toxic to humans And so it's important to measure the manganese content in these cereals to make sure that they're at a safe level But one of the problems is that the content is usually really low And so it requires a pre-concentration procedure to concentrate your samples So you can be able to measure it using ICP So this paper uses this method of making these magnetic nanoparticles these iron oxide nanoparticles It uses a precipitation procedure and then it coats those nanoparticles with this organic molecule abbreviated pan and this this molecule can absorb the manganese out of a cereal mixture that they prepare and this these Authors are not really materials. They're they're they're chemists So the the article itself is a lot about the chemistry and less about the materials characterization And so what they focus is on is on the the optimization of these different parameters for this procedure to see which Which parameters will give them the the best chemical absorption of the manganese and then they measure it using ICP Oh, yes, and so here's an example of some of their results So they they would use a multivariant experimental design where they have a List of different parameters such as pH the amount of nanoparticles and milligrams the amount of PAN and milligrams and this is the analytical measurement drive from the ICP And so they take all these different parameters different variables and there's a certain number of trials They have to run in order to optimize their Their experiment and they can put that through a multivariable equation and then they they come out with a critical Point an optimized value for pH nanoparticles content and extracting content and then they also take a look at an application of actually measuring it with barley wheat and rice flour and so the ICP would give you Calculate a manganese content and they can translate that into micrograms per gram the ICP actually gives Michael these micrograms per liter of sample and they can they can Calculate that way. They also compared their procedure to a reference So this is like a reference rice flour where the it's already been characterized It's a standard so they know that that's how much is supposed to be in it And then they use their measurement system and their measurement was very close to the standard So in summary they came up with this optimized procedure of using Magnetic nanoparticles coating with Absorbent that can absorb this manganese Separate it from the system and allow you to pre-concentrate your samples for ICP OES So there's an example that was five minutes in 30 seconds So a little bit over time. I I was a little bit worried that was as Didn't have enough time. So I was kind of making some stuff up I was adding things that I usually didn't add so first off Is there any questions about what I just covered where you guys kind of Understand what ICP OES is and you know, what kind of data you can get from it? This procedure measures the concentration of elements In a sample. All right, and you have to select what elements to look for So in this like this example here that you're just looking at lead atoms But you need to have a a standard in order to build up a baseline And I have extra slides I just wanted to see if this five-minute presentation kind of covered everything because that's the goal is that you're going to effectively explain Your characterization method to the audience so they can understand But that yeah, that's a good question and we can go and I have more slides on that after this I was just this is just like the five-minute portion But yeah, it's a good thing to practice and make sure you can let's see those reference standards for pure elements Are usually included in whatever analysis software not quite. No, so There are some internal references with the machine, but From in my experience, you have to make a reference Solution to go with what you're measuring. Yeah Okay Yeah, overall, I mean this was five slides. I think this this slide might have I think it was kind of important to show that you need a reference sample and Based on your question, I guess I could have explained that a little bit better But this is kind of give you an idea of what your presentations will be like So you have like a you know overview introduction of what what the machine does So I could have explained it a little bit better that it measures atomic concentration in a sample of you know, a specific elements you pick out And you can explain how it works briefly how it works. This is the kind of the gist of it And then give an example from literature that uses it But you kind of have to give an overview a brief overview of what the the research is about This this paper in particular It it didn't include any information on like what material they made So this this image is actually from another paper that this paper references and say like oh We use this paper to make this material and so I looked up that paper and I got this image for you guys and This paper didn't even say what the final product was that they made And that was from this paper. It's the fe 304 So I mentioned what kind of reaction this is you guys know what this type of reaction is you did it last quarter so we have a ferrous chloride Insulate in water and a ferric chloride and then you mix it together in water and you mix it with ammonium hydroxide which is a base and then It turns into iron 2 3 oxide What's the name of this type of reaction? And I think I mentioned it during the presentation No, not combustion synthesis. Yeah, this is a precipitation reaction or co precipitation reaction Yeah combustion synthesis remember you need an oxidizer and a fuel so There's no oxidizer in this it's it it's not a It's not an exchange of electrons, I guess you could say I'm pretty sure that that's correct We're changing the pH we were changing the environment of this of these ions and that makes it unstable for them By increasing the pH so they precipitate out and Then they just add this organic material Oh, you did say redox I don't think it's a redox reaction, but I could be wrong Yeah, I don't think it's redox because there's no There's no exchange of electrons like I said, so if you if you were to look at it like a poor Bay diagram If you guys are familiar with a poor day poor Bay diagram it the y-axis is like a Potential and the x-axis is pH, so we're changing the pH, but we're not changing potential So there shouldn't be any exchange in electrons, but I could be wrong. So anyways All right, let's move on. So I have some additional slides It's always a good idea to add on you know prepare for more than what you're going to present All right, you can add it on additional slides the end And that's that's the difficulty of this presentation is that you have to condense everything in the five minutes So obviously you're not gonna be able to to talk about everything that you want to talk about So you just have to pull out the most important points for the presentation And then if people ask questions, then you can you can cover those with additional slides no problem Another thing another tip for presenting I've always been told that You know the best way to prepare for present presenting is to know what you're presenting about You know know the topic well So if you guys have spent a long time working on your characterization reports You should know the topic fairly well that you can you can you can explain it without Without difficulty the other tip I've received is from Dr. Brush and it's about practicing You know just just to practice it, but you guys all know Dr. Brush, right? last or during my undergraduate my senior year I Went to the MS&T conference material science and technology conference and there was a undergraduate student speaking competition and Dr. Brush was my advisor at the time and he wanted me to practice presenting with him on my my topic and I Presented it to Dr. Brush and afterwards he said okay practice that 20 more times and you'll be okay Which kind of indicated kind of meant like oh it wasn't so good You got to practice more so you know always practice a bit But at the same time you don't want to present like you're reading from a script That's it's always obvious if you're like memorized what you're going to say and it can make it not so fluid but Like I said, the main point is know what you're talking about. It'll make it much easier to Explain your your presentation and it'll be it'll be better. So here's some background on this ICP OES This is explained the spectral line emission So, you know, this is a the energy levels the like electron energy levels of a hydrogen atom So if you you if you give energy to the hydrogen atom the electrons will Become an excited state and then they will relax back down to a ground state and when they relax they emit energy in the form of light and so for hydrogen You know, you have four different wavelengths in the visible spectrum of that light So for this example here you have a gas discharge tube So you're making a plasma of your hydrogen and it's emitting that light And then you can use a prism to separate those wavelengths of light So essentially the same thing in the ICP to just look at each intent each wavelength individually and measure its intensity And then Adams with more electrons. They have more lines to choose from This gets to the the prep that we talked about about having the standards so the one disadvantage of ICP compared to something like a different chemical analysis such as edx or Xrf you guys did last quarter Those those are very simple. You just put the sample in the machine and it characterizes the x-rays Very simply this one ICP you have to prepare your samples a lot more You have to prepare your blank water and this is not just regular di water I've been told that the di water has too many ions in it I especially sodium it has so much sodium that it will saturate the detector on the ICP It so it has to be even more pure than di water Characterized by its ionic conductivity And then you use that to prepare your samples And so you you get a standard and you have to make different dilutions and this is so you can build up your baseline so you you have like a I'll show in this couple slides that you can you can have a line on a graph that you can calculate and then you can use that That equation to calculate the concentration of your unknown sample And then also you you'll have to have a blank for your acid digest So whatever acid you're using to dissolve your sample This is an example and I'll talk about a little bit more later this type of material, but I Made this presentation a few years ago from my own research group But so I purchased a like 33 element mix those 33 elements in this solution and they're there It's a standard 10 milligrams per liter in that solution you take that you dilute it and to make your analyte standards I use a hydrochloric acid with my sample to dissolve that and so I'd have this these number of samples And then on the ICP machine you need to indicate which wavelengths you're looking for so for example I was looking for lead and sodium and iron for example in that last sample So you have to pick out the wavelength to analyze But you have to make sure that the wavelength isn't too close to other elements in your standard for example So that 33 element standard this solution, right? It probably contained aluminum and cobalt, but those are too close to these lead or excuse me these iron lines So I wasn't able to select these lines. I can only select that line You also have to make sure like I said that your blank doesn't have too many background ions that are going to saturate your ICP measurement So here's an example of making your calibration curve with your analyte standards, right? X-axis is the concentration of those standards that that you already know because you you had a known concentration that you diluted So you know those values and you would input those values into the the computer And then the ICP would measure the intensity and the sign that you know put it on a plot like this just for a specific element So each element that you're looking at and then that will make make your reference plot your reference line So it gives you that equation and then if you if you measure your sample and then you can put it on there and calculate the concentration Yeah, but the reference the intensity actually is not necessarily linear And so you want to make sure your analyte standards are close to the actual concentration that you're You're looking at so it's like that falls within this region and you don't want your actual sample to be way off because it might It won't be as accurate So here's an example of a previous research. I did like three years ago for my qualifying exam I was researching this material called the gerocyte Gerocyte is a it's a naturally forming mineral, but it's it's also often a Byproduct of the acid heat heap leach mining And so this is a process of extracting metals such as a silver and zinc out of ore where you take your ore and you Add a for example sulfuric acid and that leaches these minerals these elements out of those minerals and you collect that acid You can further refine it to extract those the minerals you want or the metals you want But one of what one of the ways to Separate the the ions that you want from the ions you don't want such as iron and sodium or potassium is Through a precipitation reaction. Oh, here's an example of poor poor Bay diagram I was talking about poor Bay diagrams that before you have pH on the x-axis and voltage on the y-axis anyways, so one of the methods is by Physically separating the unwanted elements from these dissolved ions and one of the byproducts of that precipitation is called gerocyte it's and it doesn't have any economic value so the the the mines would just dump it, you know on site and It could cause some environmental hazards if it gets mixed with like rainwater. It can cause some acid acidification of the water So the idea is how can you take this waste product and find an economic value for it? And one of the some research was in using this material as a cathode for lithium ion batteries So here's an example where they take this material and this is the chemical Equation for it. This is a potassium gerocyte. So you see it's an iron sulfate hydroxide material and The the premise of this paper is just that they took this material the material by itself as a powder in the bulk form Doesn't work very well as a battery cathode It's just the the diffusion of lithium ions in the material is very slow So in the powder bulk form it doesn't work very well And what they did is they took they made it into nano sheets and this is true for for almost all battery materials If you make it nano scale if you decrease the size You're always going to improve the performance of the battery material because you're decreasing the diffusion distance For lithium ions to to go to diffuse into the material. So that's it's always the case But you know making these nano materials that kind of takes away from the economic benefit of having this using this waste Material and even then it's still not not so good So the idea the thesis of this work was how can you improve the performance of this? gerocyte material In the bulk phase and so one of the ideas is that you could take this this ion Potassium and replace it with a divalent ion and by replacing it with a divalent ion you're introducing vacancies and By adding vacancies you could increase the lithium diffusion in the material and therefore improve the performance So I was looking at different substitutes for potassium for example and looking at their atomic radii and whether or not they're compatible to be substituted for example like Magnesium calcium are not compatible. They're just too small to be stable in that spot Ancesium for example is too large to be stable in that slot So as far as divalent ions Mercury of course is is it has been known to make a stable form in gerocyte But of course mercury is a hazardous that more toxic than than other materials. So it was off the table Strontium 2 plus and barium 2 plus there was no published literature on that So I wasn't sure if that would be made but lead 2 plus was very well known to make a stable form in gerocyte so my project was making lead gerocyte and comparing it to a The sodium or potassium gerocyte as far as lithium-ion batteries This is just some the naming convention of It's it's mineral family. There's a lot of Geology and mineralography in material science like a naming conventions and actually this this whole science about this Acetate leach mining and the refining of it That's all hydro metallurgy, but very very related to material science Anyways, and so there's a variety of different gerocytes where these all have the same crystal structure But all you're doing is substituting, you know that the the monovalent ion in the front or some of the iron with copper for example So what I was looking at was going to be For my research was natural gerocytes of sodium and then comparing it to plumb ogero site Which is lead so ideally you're in do it by introduce substituting it with lead you're going to have Half the amount of that ion so you'll have vacancies that should increase the diffusion. So this is an example of the crystal structure I actually got these just from the Jade software And some of the the PDF cards, you know You can double-click and you can get a 3d model of it and you can use those for your presentations of the models So it's a rhomohedral structure where the iron is and these octahedral more configurations The iron would be in the center and then it's octahedrally coordinated by oxygen and then on the poles the north and south pole they they Link with these tetrahedrons, which are the sulfate group so for we're self Sulfurs in the middle surrounded by a tetrahedron of oxygen and then the the sodium or potassium or lead would be located in these Here's that this is representing the lead or sodium in these large vacant spots Here I forget what shape this is. I think it's a dodecahedron that could be wrong So that's where like the lead or sodium is so if you have sodium they would spill They would fill both spots But if you had lead to plus it would only spill one spot and one would be vacant And then of course for lithium-ion batteries the lithium just kind of fills in all the other vacant spots when it works So here's an example of the synthesis I did for natural gerosite and plumbo gerosite You know you start with iron sulfate sodium sulfate iron sulfate lead chloride So this was a little bit more Dangerous because you know now you're introducing a soluble form of lead so it can easily get into your body So it was actually a lot of precautions I had to take I Forget why I added a lithium sulfate I think the lithium sulfate was to help the lead chloride dissolve because it's not it's only partially soluble And then this was a hydrothermal Synthesis right you adjust the pH and you heat it up and then it precipitates out So actually very similar to what they do in the acid leach mining is they they introduce they adjust the pH and it Precipitates out, but I just by introducing the temperature you're increasing kinetics. So it happens a bit faster And then I also ball milled it to decrease the particle size as much as possible Anyway, so I took that data and I ran through the ICP I had to dissolve it in hydrochloric acid I took the samples and dissolve it and this is that the raw ICP data for those samples where I was looking at like sodium Iron sulfur and lead for a natural gerosite and plumbo gerosite and the results would give me a concentration Milligrams per liter and I would turn that milligrams per liter into like moles per liter and then I could compare the ratio of sodium iron and sulfur and lead and Then build up in a chemical equation. Of course, I need a couple assumptions for example I had to say, you know, there's Assume sulfate was to and then the charge was balanced because it wasn't quite one to three as it should be For sodium to iron. So charge is probably balanced by hydronium, which is also published in literature So is it was not too far off of an assumption, but you can see with the ICP results for the plumbo gerosite is that There would be expected. Let's see if there's about a third of lead there a third of water So there'd be another third of vacant sites. So that's that's what, you know, I was aiming for And I in this presentation. I don't show the battery data But I am planning on next week on Tuesday. We I'll go over Some how we make battery materials like how we actually make the electrodes and in the glove box How we assemble the battery and then different characterization techniques we use for like electrochemistry and batteries So I think that'll be on Tuesday's lecture and I'll cover some of that For this material as well Any questions on this gerosite material or ICP before I move on