 So I know that just before this, you had an applications of sands one and kind of more the hard matter applications of sands, and here now we'll be talking, we were taking a completely different approach towards the soft matter and life sciences type examples. So that in mind, there's a couple of different ways. We can of course present this and present this type of slide. So I've chosen to do every three or four different kind of case studies and a little bit more detail covering, I think, the range of the soft matter bio materials type subjects that you might expect to study. That might be a good idea to study with sands and to just give you an idea of some of the techniques that are right there. So that in mind, of course, other than what the life sciences and the biological materials are, and we tend to take everything onto the big umbrella of soft matter. So soft matter being materials that have properties between that of liquids and solids. This includes a range of materials from biological materials such as your cells, your proteins, your virus capsids, etc, etc, to your polymers, your polymers are to polymers in inkjet printing. We're interested in potentially how the structure of the polymer change change, excuse me, as they go through the funnel and then how the polymer materials dry when the solvent leaves. What happens to the structure? Is it brittle? Is it flexible? Et cetera, et cetera. That's all linked to interest in the structure or colloidal suspension, such as your kind of your cashing, aggregates in your milk or your yogurts or your cheeses to your foam, such as the foam and a beer or a soap and how that affects its properties, how stable it is. And then, of course, another example is the liquid crystals. The most common or the easy to go to example is your liquid crystals that are in your computer monitors or your old-fashioned computer monitors, for example. So the first kind of case study I wanted to talk about was using microgels and contrast matching. So this is just a little bit of a background of what microgels and microgels are. Well, as you can see here, they're an excellent model system. So what does this mean? Well, in about, I think it was 1986, Pussy and Van Meaghan did one of the pinnacle studies on these different materials. They had these hard colloids and they found that as they increased the concentration, they could observe with their eyes the kind of the phase transitions that we expect to see at the atomic scale. So from liquid to crystallization to liquid crystals towards precipitation. So these are the type of effects that we expect to see at the atomic scale between different atoms. But they've shown that using these kind of these model colloidal spheres, these hard colloidal spheres, they could visualize these effects in length scales that are easily accessible in the lab, ever, using light scattering and microscopy. So, leading us to use them more as a model system and we can investigate these kind of more atoms and more complex fluids using these model systems. So the micro gels that I'm talking about in this particular study. So these are bringing an extra element of softness. So around about the same time that Pussy and Van Meaghan were doing this kind of the pivotal work in the late 80s, Pilton was synthesizing these first ever micro gels. They allowed the researchers to introduce the softness into the model system that then involved the other interaction potentials. So molecules just don't hit hard against each other or atoms don't hit hard against each other. They'll have some kind of attractive repulsion interactions that can be better modeled with a softer model system. So there's a polymer network swollen in the solvent. We're changing the temperature, pH pressure. We can affect the solvent quality and thus affect the degree of swelling of our micro gels. We have cores which are approximated with hard spheres, polymer shells, which decay as Gaussians as shown here. So hard and then a decay. Yeah. So part of the study that I'm going to talk to you for now, for the first third of this presentation is how does this softness affect the phase behavior of these colloids? They've been studied. They've been studied not to death, but they've been studied quite a lot. And a lot of work has already been done understanding how these micro gels behave in concentrated solutions. I should say that these are on the couple of hundred nanometer length scales rather than some more like nanogels and micro gels. But so we've been seeing that as we increase the concentration in solution, they can be swell, they can interpenetrate, they can deform, they interact with their neighbors and depending on the kind of the molecular makeup of the micro gel, they've seen these different interactions. The study here. So this is the normal mixing pot for these polymer micro gels. If we take out this cross link reagent, we can create these what are essentially super soft micro gels. Previously, it was shown that the super soft micro gels were shown to crystallize. So you can kind of see at a particular concentration, the data essentially refers to the concentration. At a particular point, we get these little speckles indication indicating that crystals were formed. So the aim of this study, I want to tell you about was to see how these super soft micro gels responded to crowding. So just a quick note, as I mentioned, the CETA is essentially referring to the number of swollen micro gels, the number of micro gels divided by the volume of the swollen micro gels divided by this, the total volume of space occupied by them. But it doesn't really matter. Just remember that the CETA is more or less proportional to the concentration. So this is where we get into a small angle scattering. In this particular case, we started off with a small angle X-ray scattering. So we use this as a tool to have a look at the overall micro gel to micro gel arrangement. So this, in effect, is our structure factor that you've heard about over the last couple of days. If we look at our 2D scattering images on our left hand side, we go from lowest concentration from figure A right up to highest concentration of figure I. I think you might recognise are these isotopic rings. So here we have the ring. It's quite small when our micro gels are at the lowest concentration, right? So quite small, small rings, obviously in first space, the further away. As we increase the concentration, it makes sense, not hard to imagine that our micro gels get closer and closer together. And as such, our rings get bigger and bigger in the in first space. So our rings are getting bigger and bigger. And then what they saw with the samples was there was a sweet spot, where at about this kind of middle range, right, not point 8, they started to form these little, also these little speckles, these little speckles forming to more crystalline type scattering materials, kind of correlated to what we saw physically whenever we looked at the samples, and we can see these speckles. And then again, if we move past this sweet spot in concentration, the rings continue to grow bigger and bigger and bigger, as the micro gels are continually continuing to pack together. But you'll note at this point, at these higher concentrations, we've now lost these crystalline type peaks, indicating that there's a particular phase transition that happens through this particular concentration range that is promoting the crystal formation. So of course, we see these crystalline structures. So then we can relate these crystalline, sorry, these crystalline peaks, or backbeats, and we can relate these to a crystal lattice. So shown from the examples here from face centered cubic, hexagonal closed packed, body centered cubic. For these type of materials, typically they found that hard spheres will form and cross like micro gels as here will form FCC or HCC patterns. Sure, you've seen before in the past couple of days, when we have these 2D scattering patterns like shown here, so these x y scattering patterns, we can take them, if they're isotropic like this, we can do a radial reduction over the entire detector area. So this being our lowest Q and out here to your highest Q. And we can get the information as shown on the pattern here. What's important to note, and actually I probably should have put a more convenient figure in for it is we've actually no, no, it's fine, just essentially extract the information from the structure factor. So this being our particle to particle interactions. So whenever we extract our information from the structure factor, and we plot it against our Q range, we can quite clearly see as we expect along these crystal samples, these little peaks, corresponding, so these peaks represent the crystal lattices. So a proportion of the crystal lattices that we see within our micro gels. So far face centered cubic, the last of constants that we would expect if we look at our first one, the second lattice conference constant that we would expect corresponds to this little bump shown here. Then if we go to our third or fourth, we don't really see anything. So it implies that this order is on quite a tight scale isn't very long range ordered. But we definitely see this little bump here. Again, comparatively with the slightly different concentration. What's interesting to note though is that the second peak, the second peak doesn't correspond to anything to do with the face centered cubic, and it didn't correspond. So between the first and second peak, there was no crystal lattice that would have those type of peaks in that particular ratio, implying that we have this existence of some kind of second crystal lattice, or seconds because lattice in this case, we were various other things pointed towards the formation of body center cubic type structures. It's really super important. But we essentially saw the coexistence of these face center cubic and body center cubic structures. So that's great. We have some indication of what's going on in the microscale to micro gel to micro gel arrangement, which is perfect. That's what we can get for very useful information from SACs. But what we're also interested in finding out is what's happening to the micro gels on the individual basis, right? So we want to know whether they're faceting, whether they're changing shape, are they interpenetrating? And this is where the magic of neutrons and small angle neutron scattering comes in. So for sure, Andrew, Adrian or Elizabeth or Wojcik have talked to you about contrasting and contrast variation studies in the previous talks, but just as a quick recap. So say, for example, we have a core shell particle, we have a core, we have a shell, and we have a solvent, right? So each of those three things will have a different molecular make up a different density, and therefore have a different scattering length density. So our neutrons will see the transition between the core, between the shell, and between the solvent three different components in this basic example, can be a little bit difficult to interpret. So what we can do is by cleverly mixing or matching the scattering length density of our solvent, for example, by mixing H2O and D2O, we can match the scattering length density of the solvent to that of the shell, isolate the scattering from just the core. Or if you want to see the shell, of course, we can match the scattering length density of the solvent by mixing in different duotated and hydrogrenated solvents, excuse me, matching that of the core, and we just see the scattering from the shell. So as mentioned previously, this selective derivation in combination with neutrons allows us to investigate selective parts of complex assemblies. And by combining exercise and neutrons, we can get even more information. So let's take a different approach. Now we're not just talking about one particular molecule. Now we want to have a look at how we can deal with this in more complex systems. For example, a system of crowded micro gels, our micro gels in a crowded environment. So for example, we take our first sample, we have our solvent, say for example, D2O, we have all these micro gels visible. So this is a load of duotated particles, and a few hydrogrenated particles. But other than that, they're the same, the same size, the same density, everything like that's the same. If we look at the duotated and hydrogrenated samples with x-rays, we see, as expected, so we see a scattering pattern, so our IFQ on the left hand side, which is going to be proportional to our form factor, our shape of our individual particles, and our structure factor. So this particle to particle arrangement, as shown here. But now, if we match the solvent, so this, for example, D2O, so if we do a mixture of D2O and H2O to match the scattering life density of the duotated particles, we render these duotated particles invisible, and we just isolate the form factor, so the shape of these individual hydrogrenated particles. So these hydrogrenated particles will have all of their very duotated particles, forcing on them, interacting with them during the interpenetration or changing their shapes, for example, but we don't get the crowded information from the structure factor on top of that. So whenever we measure neutrons on the exact same sample, we just isolate this form factor information of the individual or the more dilute hydrogrenated microgels. So as you can see, exact same sample, we lose all of this peak information, and we can isolate this individual information. This means that we can get from one sample using x-rays and neutrons, both pieces of information, and then therefore, by dividing the sacs data, which is our IFQ, proportional to a PE of Q and RS of Q, by the sans data, so our IFQ, which is just proportional to the form factor, we can also then isolate our structure factor information, which is exactly what we did to get this information here. So this was the sacs data, so our PE of Q times IFQ divided by our sans data, which was just our IFQ, to isolate the structure factor. So then this is how we can then analyze this data forever. It's a really, really lovely use of using the x-rays and neutrons in combination to get more information from your sample, and I'd highly recommend trying a similar approach if you have these type of systems. So moving on, one, the common question, when we have these soft matter materials that we're doing selective adjudication, or we're doing kind of hydrogenation, we're mixing, so of course we can synthesize particles that have the required amount of deuterium versus hydrogen for all ranges from right free from bioscience to material science. One question that is always asked is, can we really believe that these two materials are the same, right? We know that protons, yeah, hydrogen and deuterium are almost the same, but they're ever so slightly different. So it's always good to have a method to check and confirm to everyone else that your materials are actually comparable. In this case, this is exactly what happened. So they looked at the systems of the protonated samples and the systems of the deuterated samples. They had a look at how they changed their shape as a function of temperature. They saw these phase transitions, so they deswelled at almost exactly the same temperature between the two different species. They also changed sizes to roughly the same size. This obviously is an ideal, we can see from about 45 to 55 whenever they're deswollen, but they're coaxing us for us to be pretty confident that this is a reasonable, a reasonable comparison. We then took a step forward, so we also, oh no we didn't take a step forward, sorry. So another thing, okay, so we have our deuterated samples. One thing that we need to do before we can do the just measure with the sands is of course we have to identify the scattering length density of our deuterated micro gels in order to match them out. So on the left hand side here, we have, this is maybe a slightly different approach in terms of, I think probably Adrian showed you the approach of going to the eye of zero and working out your scattering, your contrast matching point from that. I also like this approach. So here you have the same concentration of micro gels, so of your deuterated micro gels in different weight percents of D2O. So obviously you can see at the, say, 100% H2O and 100% D2O, you have the greatest contrast. And as you start to go towards more of a mixture between the D2O and H2O and get closer to the contrast matching point, you lose the contrast and so the scattering density drops off. If you take five different, if you take the value of each intensity of five different cue points along, along each of these data and then you can plot them in the format shown here, where they overlap and cross over the zero, so your, your difference in scattering length density of being zero, so your contrast matching point, if you're lucky they'll all overlap nice and perfectly and this is our contrast matching point for our deuterated micro gels. Of course then you can compare your samples, so this time this is each of the samples, so these are mostly deuterated with a few hydrogenated and then you can measure them with sands. In this particular case exactly what we did, so we have the increasing overall concentration of the micro gels and in this study they had a look at how the structure of each individual micro gel changed over time, so just for the interest of being complete. They saw in this study that the micro gel cells cells first collapsed and then as they increased the concentration further, the micro gels themselves became more condensed and more compact and a quick this end at that point allowed them to perform a comparison between the sands and the sacks data, so from our sands data we acquired the diameter of the individual micro gels and from the sacks data we could acquire the neighbor to neighbor distance from the position of the first peak. In the red area they saw that where the radius or the diameter of the micro gels was more or less or sorry the radius of the diameter of the micro gels is more or less comparable to the micro gel to micro gel distance, so they're swollen and just touching but not so swollen or so compressed that they're ever further away from each other or they're starting to penetrate. It was in this sweet spot that they were seeing the formation of these crystalline type samples. That was the first study which essentially I wanted to show you in order to show some of the elegant or I think at least some really elegant approaches to using contrast matching and the type of information you can get from even relatively simple systems such as concentrated solutions of micro gels. The next topic I want to tell you about a little bit more as I mentioned yesterday is rheology sands type experiments. So this is going to start with a quick overview on what is rheology just to get everyone on the same page although I expect everyone in the audience here may already know. So first of all what is reality? So reality is a study of flow. So what controls are materials rheological properties? Well whether that material the materials in a structure, how is it built, what's its molecular makeup, that material's morphology, what is the shape and size of the components, do you have needle-like structures, bulky cotton-like structures etc. Also what are the external forces that are acting on the system? Is the system under flow? Is it under a lot of pressure? Is it being stretched to deforms? And finally what are the ambient conditions? What environment is this stress material in such as the temperature, the humidity? Is it under some kind of light or something like that? With that in mind liquids we can kind of put all materials in the world and planet and the two different groups of liquids and we have solids right? Liquids flow, solids don't, but of course materials are more complex right? We have materials, viscoelastic and fiscoelastic materials that have some component of viscosity and some component of them that are elastic. Fistoelastic liquids or viscous liquids rubber are liquids with an elastic portion that when they're stressed they flow but exhibit a small amount of a small amount of stiffness. So I see viscoelastic liquids and then you have viscoelastic solids that when deformed not too large they try and retain their shape. So say for example you push against a tire it will it will change its shape but it'll push back at you and then oftentimes reform its shape. And then you take that to the next extreme and of course you have solids which always retain the same stiffness and don't deform until of course they break and become brittle. So this term viscosity has come up viscosity being the measure of a fluid's resistance to flow by an applied deformation force. And with this we can use the viscosity material to understand the internal friction of that fluid. So for example here we have honey it has a high viscosity, it has restriction due to its molecular makeup and morphology leading to internal friction. In contrast we have water which flows super easily it's got low viscosity and has very little internal friction. Then moving on to the kind of the deformation forces that we can apply to our materials this is of course true whenever the type of forces that we need to consider when we want to do these experiments. What type of deformation forces can we apply? Well of course we have tension where we pull from the opposite directions on our material. We have compression where we push in opposite directions in our material. We have bending where we push outside forces but they're not aligned right so it results in bending of the material. We have torsion for example if we twist and the one that I'm going to focus on for the purposes of the reosan stock is shear. So this is where we have unaligned forces pushing in one direction like opposite directions to each other resulting in a shear internally within the material. The quick note on viscosity, shear stress and shear rate. So we have say for example a tube we have a material being forced through that tube. The material in the inside so kind of this middle line will be flowing more freely than the material on the outside line which is experiencing a friction from the outer walls of the tube. This distance here so the distance between the middle and the outside sharing plane of the material we can use this to determine our shear rate. So it's the difference in viscosity between these two levels divided by the distance that gives us our shear rate. We can also measure the force that's applied to get our material through a tube for example for honey through a tube is a lot harder so it makes a lot more force to push it through a tube than for example water or I don't know toothpaste. We can then use this to determine our shear stress so this is the force applied divided by the area to which you're applying that you need to apply that force to. So important to note that the shear rate is proportional to the shear stress. High shear stress we can expect a higher shear rate. Higher the viscosity higher the shear stress required flow at the same rate of a less fiscal listen. So exactly as I said in order to get honey to move just as fast as to get the water to move you need to apply a lot more stress to the honey. And viscosity is equal to shear stress over shear rate. So some things that we are typically interested in when we do biology experiments are these flow profiles. So first of all before I promise you I'm about to get on to the scattering bit in a minute. So let's consider the different types of flow. First of all we have Newtonian. So these are Neclonium fluids as you may know are fluids that have a viscosity that doesn't change the shear rate. So it doesn't matter how fast you shear water. Its viscosity will stay the same. Non-neutral and then the second class materials are non-Newtonian. So first of all we have our pseudo plastics. These are shear finning materials. As we shear them the more and more we shear we increase the shear rate. They become less and less viscous. For example mayonnaise is gloopy in the jar once you start to spread it it becomes less viscous. These types of materials for example you can think of them as pseudo plastic in the imagine that you have a plastic that's really warmed up and coiled together as you apply force. These coils can start to disentangle. As you apply further force the change of disentangled enough that they can slide quite smoothly over each other resulting in the lower viscosity. We then have our dilatant shear thickening materials. This is where our viscosity increases with shear rate. So for example quicksand or cornstarch. I think I had a dodgy little video I did. So you hit cornstarch really hard with a hammer. You get resistance but if you hit it slowly it can go in quite easily. So this is there's kind of an explanation for this whereby whenever you hit something really hard the energy dissipates super fast in the molecules and they start to organize and form like a resistive structure. Well if you go slowly there isn't that massive impact of energy causing all of the atoms to rearrange and you can kind of slice through or push the hammer through the material. Then we have finally our fixotropic materials. So these are shear thinning like the many as example but this time time dependent. Such as ketchup where you give it a shake and then you can pour it, coatings, paint etc. Just to show you what I think as you can see here so we have our shear thinning and then it takes a little time to recover the same viscosity whenever the shear rate drops off. So we have this degree of hysteresis. Talking through this is I think quite a nice example of where these kind of fixotropic materials are important. For example with paint. So you have a paint. You have it sat in a pot. It's quite viscous. It's static but it's quite viscous. You start to stir it. It gets a little less viscous. It gets a little easier to apply. You apply it to a wall. What's important is whenever you remove the brush you want it to not completely go hard and stay in its place. You want it to be fluid enough that it's able to kind of spread and soften down so you don't get these kind of paint stroke effects like people typically don't want when they're painting their walls. But also you do need it to dry because you don't want it to stay fluid for so long that when it eventually will just drop off the wall. So getting the combo of this fixotropic properties where we have our shear thinning and then the time dependent recovery is super important whenever they're designing things like paint. And they can control how your paint or your material behaves by tuning its structure relationship. It's parts of the material structure to tune its properties. And that's finally when we're getting on to our reosans. So what we're interested here or in my world essentially is in the structure property relationships. So the rheology of a complex fluid is directly related to its structure. We need to understand how a material reorganizes its structure due to flow and then the relationship between the flow and the stretch which govern the bulk rheological properties of a system. You can see numerous examples on the right hand side here from different entangled polymers for polymer melts, surfactant solutions. They obviously have their structures and then how they behave. Latex paint, whipped cream mayonnaise, blood plasma. These are all materials that we're very interested in being able to tune their structure in order to tune their the properties that we actually interact with. So as you've seen many times before for this we want to use our small angle scattering technique to probe the structure of these substances from the nanometer to 100 nanometer length scales. This is ever so slightly more or less the slide I showed you yesterday. So this reosans is an excellent tool to help us understand this structural reorganization as a sort of flow. And in this study although I mentioned yesterday there are numerous shear cell examples we're going to focus in on the QS cell where we have a cup, we have a bob, the inside cup can spin and share and add deformation forces to the sample that's in this gap in between. So again I briefly mentioned yesterday about the planes of interest whether it be this radial plane going directly through the cup so this is our neutron beam going directly through the cup, our tigental or our one-two shear plane which is as I said slightly more difficult to probe but each plane offers specific and unique information for describing these structure-property relationships. So what I mean by that it's quite handy, this is an example from Norman Wagner's group in the States but I think the best way to think about this for me is imagining you've got spaghetti and a pot, long chains of pasta and you stir them right, you create a sort of pseudo-wolf vortex, the pasta chains start to line up on the outside of the pan right. This is kind of what's happening here so we have our cup, our ball brother that's spinning on the inside, we have a cup on the outside and we may have so in here it's kind of long blobs but you have long chains or anything that has some kind of anisotropic structure, they are encouraged to align as you're doing the shearing. What I want to exemplify here is the different information that you might get at least pictorially from these different planes of interest. So for example if we look at a one free plane so this is our pointing directly through the middle of our shear cell we can see the kind of the side for you so as shown here in the sketch of these particles. If we look at the two free planes so this is now going along the side of the bob so this tangential version sketch shown here we now see with our scanning pattern the cross section of these particles so here for example if it was some kind of cylindrical blob it would be the spherical ring as a side for you. You can see quite clearly from the scattering patterns the difference in the type of information that you'll get from the two frames of perspective. As I mentioned it's particularly hard with neutrons and x-rays to use the we can't use the Anton-Paur rheometer that I showed previously to look at this field of vision so looking down you have to design special cells for these but whenever you do use one of these special cells known as a one two shear cell you'll also get a different field of vision again you have a different orientation of your particles and say for example you have big long chains of spaghetti you'd expect them to bend following the curvature of your of your cell and that's what you should see this kind of anise trophy from this top view so you can kind of see it's not completely symmetrical in comparison to how this image here is so all three fields of vision give you really important information about what you can see inside your sample. With that in mind I haven't got one particular example to show you I kind of just wanted to give an impression of like the multitude of different types of materials that can be measured during this technique one of them are one of the more famous Neutron Scattering Experiments for Rheosance is by the group again of Norman Wagner in the States and he was studying the ballistic impact of say a bullet hitting Kevlar woven materials the Kevlar the super resistant super strong body armor type material when it was impregnated so loaded with colloidal shear thickening fluids so these shear thickening fluids are the ones I said before you have a big impact they reorganize become super stiff and super resistant but imagine if you're you're moving quite slowly you hit them slowly they're softer more easy to wear it's of course ideal so you can actually show you the data first you can see it here that we have our viscosity on this side and our shear our viscosity drops off massively with increasing shear this and that due to the structure of the colloidal particles embedded into the material what I love about this application is if you can imagine with your Kevlar suit you want to wear it for protection but in your day to day you're walking around you want it to be smooth soft right so you're moving slowly you're not doing any base impact it's soft it's smooth it moves with you whenever you add that's ideal for something that you're wearing once you get hit with a bullet of course you want it to work and go super super stiff so it seems like the perfect application for this type of material another example is for materials for using investigating materials used for polymer solar cells as I mentioned in the very first slide we're often interested in how materials behave under processing which is where rheology can oftentimes come into it because often things are a injecting inject jetted and just probably one word printed through a fine nozzle they undergo sharing in that kind of very typically in manufacturing processes so this is an ideal application here and here they used they studied the structural properties of polyphiophene so the light absorbing polymer for organ and photophotox and they studied so these materials were loaded into gels and they studied the dilation process with the rheology so as the something's dilating obviously it's viscosity turning into a gel its viscosity is going to change over time so we can kind of investigate that of rheology at the same time measured the structure directly with the sands so the sands showed that the structural features evolved through the dilation project process which could be controlled by either re-dissolving the polymer gel or changing the solvent and the final reosance example I wanted to show you kind of following on from one of the questions yesterday this is definitely not exactly it but this is we can always take our sample environments a step further so while these rheology sands set up so quite ubiquitous in all all of the institutes there's always room for further improvements so this is a lovely example where they had these dielectric sensitive warm like micelles is less than they had that they found that they were branched worm like micelles of this material and as so they could transport charge because the different charge gifts and stuff on them but it was the level of conductivity was super highly related to the amount of branching and they found that as they sheared the branches would split apart that become more linear and therefore the conductivity would drop off and the way that they could see this was by doing in situ rheology with in situ impedance spectroscopy so they could measure the charge moving across the material as they were shearing it at the same time as measuring the small angle scattering so investigating the structure at the same time so as I said branched worm like micelles should fast breakage time so they broke apart unbranched micelles whenever they also compared with just a written only linear worm like micelles these are long chains of surfactants they found that as they were shearing them they're they're electrical properties didn't really change because there was nothing to break apart okay so the very last kind of group of samples I want to tell you about or the final little kind of study I wanted to tell you about was an example based on proteins I should say as a caveat I've chosen an example that was led by Adrian Sanchez Fernandez one of the other speakers on this course so please feel free to ask me any questions at the end but whenever you want but um thank you particularly interested and I would encourage you to chase them up this all work forms a part of a next bio form collaboration within Sweden for formulation and processing biologics so in this particular study Adrian was interested in looking at how proteins and surfactants behaved and formulated products so I don't know if you know but when you have a protein such as for example human growth hormone that needs to be medicated to someone's solution as someone I don't know in a medical type environment it's it's obviously in a solution the proteins typically undergo different aggregation processes as soon as they're left for a little while they can become destable for solution etc etc and one way to overcome and to make these materials more stable and to last longer is to add in surfactants so they surfactants are known to play an important role in the stability and performance of formulated products the goal of this study say our goal the goal of this study was to develop this intertectic interrogative approach to understand the conformation and colloidal stability of protein surfactant systems so I'm not going to focus on all of the other characterization techniques but what I will tell you about specifically is the contrast variation small-angle nutrient scattering studies that they performed and a very little bit about the constrained model fitting that they did so in this scenario they took their protein which was their human growth hormone as shown here or the crystal shown structure phone shown here and the anionic surfactant SDS sodium dezecal sulfate they formed these small-angle nutrient scattering measurements with contrast variation well it's interesting here so if we take our two different spheres we have one of these spheres is a protein one of these spheres is our surfactant and they arranged it so they had these four different isotopic mixtures that we used to by tuning four different isotopic mixtures whether that be matching out the protein and surfactant to each other matching the protein to the solvent matching the surfactant to the solvent or using the zero average contrast condition that might have already come up they could probe different elements of the aggregate altogether so unlike where for the first example I was showing you with micro gels whereby they were trying to isolate the overall structure in this time they're trying probe different particular parts of the aggregates of the atomic aggregates so they use these four different structure four different isotopic mixtures to follow the structural changes occurred with the system as they added an increase in concentrations of SDS each of these compacts contrasts use the specific isotopic labeling to focus on a particular feature of the system so as you can see when we have our surfactant on our solvent matched we should isolate the structure of the protein backbone by itself when we have our protein and surfactant matched we should isolate the structure of the complex when we have the protein solvent matched we should isolate the structure of the surfactant now this the SAT condition this is our zero average contrast condition this uses this essentially we when we have our mixture of our okay I'm trying to think of a better way to explain it the formation of complex if we form a complex between our protein and our surfactant we will either lead to essentially no effective forward scattering because the contrast matched conditioning is achieved but safer so if the surfactant is uniformly spread all over the protein we should see no scattering as in a flat line here there is no scattering effect but if segregation of compounds occur within the complex for example if our surfactant is becoming aggregated in clusters along our protein then we should see a broad peak appear from the density correlation between these complex domains so essentially we'll get little aggregates of the surfactant on top of our protein which will then start to interact with each other and we should get some kind of scattering condition from that the zero average contrast condition is for me anyway quite a complicated it's quite a difficult condition to try and achieve with normal experiments but when it works it can be incredibly usual as it did for Adrienne here so first of all of course we have to measure or they have to measure the the bare protein by itself so that's something to work on so they started with the structural characterization of their human go-for-moon so this is the their scattering data so the human go-for-moon is a small globular protein which it is built up of four anti-parallel alpha helixes in brief so they use their peridistribution function was initially determined for the IFT approach this is all stuff that Vojcek I think will far better describe to you but they also took the crystal structure of the protein and used this using the Cryson software to also try and fit in all honesty the details are quite complex and I probably refer to your paper but in essence we have a globular protein which has a diameter a maximum diameter about 52 amstrons radius of derivation about 18 amstrons it behaved as a monitoring solution so one of the concerns with this project was that it was starting off aggregated and as a contrast matching point of about 60 percent H2O so then he found with his contrast variation and the science measurements they could study the changes in structure and interactions between the complexes they had various phases of the interactions so various complexation phases so whether it be a pre-agric critical aggregation phase where the protein was essentially untouched I have a better figure here where SDS was being absorbed onto the surface of myself and you got subtle conformational changes of the protein then as they added more SDS the protein became more and more unfolded as it was absorbing more and more surfactant then got this clustering as I mentioned from they could see from the SAC approach so the SAC approach on here kind of have to stress to say it but there was in comparison from left to right the SAC approach you can start to see the formation of some some kind of some kind of intensity implying that we get this SDS clustering and these clusters are starting to interact with each other and then finally leading to this final stage to this post-CMC stage where you have a decorated micelle morphology so here we have a completely destructed protein structure that's completely mixed in with an SDS micelle so obviously in the process of deciding what concentrations of surfactants due to stabilize this is something of interest to us because we have to understand what our surfactant is doing to the protein Adrian did this lovely sketch for his paper to show how the protein changed from increasing concentrations of SDS they also compared these studies with some NMR NMR studies so the sands was used to probe the tertiary structure of the protein and then it was complemented with the NMR to probe the secondary structure of the protein so with that in mind I didn't for some reason put a conclusion slide in or a summary site but that's all I had to talk to you about in terms of examples with using applications for soft matter and biological type applications of sands if anyone has any questions please shout them out I'm sorry that was a bit of a rapid case for a couple of examples but I hope it was useful does anyone have any questions as Adrian others have said I will of course put these slides online with everybody else's and I think I don't know if you've been sent the link already or you'll be sent the link so you can access them all and of course be around tomorrow for the lab sessions and then the presentations on Friday but if that is all we can leave it there