All right first of all want to thank our border and the people in this wonderful event and of course for inviting me to participate in I'm going to tell you how we can control the joy metric symmetry of nano particles in this in this nano particles can have a very interesting optical process and the catalytic a prop this and they can also serve. Actually if you want to study how this assemble in different ways and the symmetry breaking is a very common phenomena and the symmetry of. Example over here that Pio is supposed to have is circular symmetry if symmetry is broken you know what's going on right you're going to have you have basically have had that pile so you're going to get in trouble so you affect symmetry breaking is also volved at the very beginning of life development so in this case. For a story to be secret out and in this process typically they are surrounded by and they are of a different type of Self's form this a highly symmetrical structure it's a concentric structure and at a certain point as free the symmetry this symmetry is going to be broken this is through the See question of some fluid actually form some of the all of them so basically you only have a fruit come out from this side of these cells and eventually will push And finally this is going to be able to come out of the air OK So that's basically the symmetry for you can involved in that event over life and here is also quite a common experience you might have had right where you sit over here at this table it's so symmetric you feel confused left side by side which is. Going to pick up. The symmetry were broken automatically someone else callously pick up the classes from the left side all right side then everybody knows which side to use the right so that's basically this kind of symmetry can typically a way or code spontaneously and a randomly and ones that occurs once that has occurred this kind of pattern probably can be preserved. In the conditions of being changed if you keep the same conditioning the symmetry definitely could be continued somebody made it so let me tell you how we get started on this kind of problem that was about a like a ten years ago one all my students. Was doing this and this this of zero one nano cubes and on the right conditions with the help of some polymer in this particular case is a polyvinyl production is appalling what they combine to the one those surface of silver so basically you can form these coops as a result for some reason she didn't obviously the products immediately she just keep but there's particles in the solution for Libya longer maybe like a one hour on longer and then she somehow inject more precursors into this solution and she probably was trying to see if she can get larger and cubes or maybe this cubes can grow into octahedron if you don't have adequate P.V.P. to passively didn't want to anyway so the Chiffons I'm seeing a very strange entry in the shape of these products essentially complete different from what we would expect and for most students are probably about just throw away this them post and start the nuisances again unfortunately she didn't look at this very carefully and then we realize that this is a very interesting particle and that it was basically a form of. No seats in this particular case however the Crowes was not uniform on all six side faces basically a surreal done well somehow turn done. Done and the other surreal will be able to grow so you eventually this particular shopper ten is something we call semi truncated octahedron S. So you magic octahedron you truncate the story of the six corners that's read it in the grow basically OK and eventually your pin this kind of structure and this structure can sit on the surface and when you did you had to prepare Sampa they basically can take these two different patients depend how to sit on the surface one is against this and one on one surface look a like a triangle projection on the T.M. So that's basically those guys over here and the same time they missed it only they missed it against this one no surface so that will give us the different approach actually it's like a house because his house projection So that's basically the other arm population of this come apart because so basically this particular may look a very annoying uniform but actually it's very uniform is just the shape it's of. An arc to hit on shape so this gave us the starting point to so we have one to really study to see how we can control the geometry shape and the symmetry of this on the particles and this also of course gave us a hint see that media across might be a very good example you can make of the seed which is one particular size and shape and then add a more precursor to see how the symmetry where be changed in the gross process so that gave us to me two rows approach that also has been widely used in industry for example we have to rely on Silicon Valley for us to make chips and those silicon their single nanocrystals actually well pour out from a mail out various tiny seed at the very tip of the beginning OK And then the. And the big OK in this way and all of this concept we can just a run in the social face so you magine you can have a solution over here you have seats suspended and that you introduce precursors you can introduce because at the specific away you want for example in a kind of concentration you have for this precursor and the pace at which you introduce this precursor and of course this person can be reduced at a certain radius you have the right of reducing it in your system anyhow this newly formed Adams added onto the surface of seeds and typically we would expect that to have some symmetry. Preserved in this process so for example this cubic a seed can grow our lawn that calmness and the edges eventually develop this and the symmetrical structure because as Coffin structures so that's of course the symmetric process so at same time you can also Obs open the symmetry for us why is that why you think about this see these are two dimensional model OK you think of this side a face you have four side the phase and the Four Corners OK this four corners or four side effects is equivalent to each other in a sense OK you cannot do the really differentiate between them so now when you add Adams for their surface OK you can add Adams to all of them that was key but the symmetry of the origin the seat on the other hand somehow if the Adams you generate in a system not adequate to be added on to all of these off or you could have been the corners you may have this pattern develop this in this case symmetry where be reduced or broken up and this particular case so as a result of that you're going to generate the structure you know which is the same symmetry as the seed or is that given the symmetry so this it would be awesome if your broken situation you can also have a different the patents this is a one way. You can also have just a rose couldn't from two of the four corners or one of them in a cell and so forth so this about gave us different final products of course and last year we were published a short perspective advocate in chemical communication actually if you're interested I can take a look at it so basically this is a cubic seed in this particular exam but we show we can have the same symmetry to form a cautious structure you just deposited new Adams a run the entire surface of the seat you're going to generate this symmetrical structure or you can does deposit the Adams onto one of the side of faces generally that a generous particle you have these two different materials next to each other side by side now would be basically a generous particle so hard to really control and this is so that's basically the question right so I try not to be a novice so difficult OK I just want to point out in the. Many chemists in the audience this is a single arm you have this seed so I'll give when the ears are worse you can really control the hominy Adams are going to be generated in your system if that number but yours is lower than the equal to side on the surface of the seat and the symmetry of probably would be reduced automatically in the specific a pad So for example if we only have Sri Adam's being generated if we tried to deposit them onto the six side the faces of these key because seed What can you do you can only probably reach out to three of them not all six of them OK but of course this three can also be dumped onto one of the side of faces or two of them at the most surreal of them so yes since the symmetry has to be reduced the cost unless you generate that large and numb a large enough number all of this Adams that can be deposited on to all these different aside if then you can preserve the symmetry you can have form so you can have close to generate a cautious structureless So basically if there isn't a control over. Different numbers of Adam's relative has a number of seeds or are the number of equivalent sides on the surface of seeds and then you can control the pattern is a symmetrical and symmetric and in this case could be grown from one of the side to faces that generate this generous particle and could be on all six sided face to generate this cautious structure and all maybe just on three of the six sided faces generated is of course our structure above this is not a going to be concentric OK this is the seed be located at one of the corners to form these and symmetrical structures and although this can be easily controlled to use in syringe pump it just drip This produces through washings at a specific ingestion rate and you can change the pace between the droplets and then you will be able to control your pet it so here just show you the example you have grows from one of the side effects this of these Palladium could be a seed and what you deposit over here you see over so you can see it when you add a more more silver precursors you are going to obvious of a larger volume of silver been deposited but they are only going to be deposited on one of the side if it is so there is zero world volume can be increased but not the going to be moved to other side if they are localized to want a particular type so that's why I'm in the symmetry break can patent could be intent if we can experiment the conditions are fixed and this situation you're going to have. A run the entire surface of palladium seeds and you're going to generate ideas cautious structures and this is a situation you have. Three of the sick inside a faceless you're going to generate this structure you can see this in more clearly is so that's why we use to define the matter so you can do elemental mapping afterwards so this is a situation you have the Palladium next to each idea forming. And this is concentric. Structure and this is a one way is the seeds located at one of the corner sites OK So that's basically where we are well defined saying fragged by for the fine tuning this ingestion scheme you can generate over on one of the side faces two three four five and six all of these different schemes as well possible if interested take a look at these people have popped a while ago and then we'll try to understand you can do some home to do control OK basically under what the specific injection rate and concentration you're going to generate the specific pattern of symmetry breaking so in this case with data some analysis on the reduction kinetics on the. And that is kind of simple you think about this is seed suspended over here you have a solution be injected and with specific a pace and its drop have the same concentration of precursor So that's kind of simple and for the first the drop you add into the solution that will be reduced by the reducing agent to have this in the system but generate the atoms for the gross right so you see the concentration of wealth decrease because of the. High ever before all of this precursor reduced to the zero you have the second the drop come into the system so that's basically where you have the second the drop been added and the concentration on cost of a jump OK and then you're going to have reduction again and again and assume so force so that basically refracts How does concentration in a system change as a function of reaction time and this is very similar to the situation when you take a medicine every day if you take one every day eventually in your body you are going to have previous day becomes infusion of the Medicine at three this is similarly shown over here basically the concentration of precursor in the system eventually will be also waiting between two numbers one is a new low one is in a tree that refreshes the. And the high concentration you can achieve. Of these precursor social and easy to calculate is OK if you know they need your concentration or precursor in the with the actual rate of this precursor by that particular reducing agent and taught over here years just the duration between two and if yes in the droplets and once in though there's numbers you would be able to calculate basically you can see when you change those define the parameters you can have different and and low this to differ and are basically limits for the concentrations and then we end the lies the pot of course we are going to observed after a certain period of time and you can analyze how many of them are going to be symmetrical and symmetric symmetric and symmetric so we fund that basically under certain conditions this condition years of when this Anglo is larger than eight some hundreds eight OK we haven't been able to understand why it's eight and in this region you are going to have majority of the product has been and symmetric symmetry somehow is broken and when a load is smaller than eight basically you're going to generate symmetrical structures OK So basically have rows on all the side of faces and then we start to understand. What that we can propose while when you put this Adams onto the surface at the very beginning as I said it has limited by the available number of ADAMS The symmetry is supposed to be broken OK at the very beginning high above this. Pattern also. Tend to do it in the afterwards. Process and this is the other two reasons one is this Adams could be able to migrate to other areas if temperature is high enough OK they don't have to be localized to this initial site if they can diffuse to other areas so symmetry be preserved you're going to achieve symmetric. Rose and I same time if you have too many precursors have been added They may also have edition a new creation on the size so basic and that has to mature way of the also preserve So basically they've gave us some a semi quantitative understanding under which conditions you're going to generate this and symmetrical or symmetrical just two different categories of nano particles of course the rest you're trying to do more systematic study to figure out in on the use that of which condition you're going to generate a specific at a particular symmetry OK and this symmetry with actually operate can phenomena is kind of universal OK We just didn't pay much attention to this so here is them to show you another example of how we can generate up to he draw and the tetrahedra there's two related to nano Christus there Sophia's Abos cover the VI one on one OK but they have different volume to surface area ratios of cause this symmetry is very different so in this case the wrist other ways of the heat of seed and initial stage both of them will be able to generate octahedron using different precursors and then suddenly for this type of precursor P.D. economic and that the symmetry would be reduced so basically you think about these up the heater you have some eight sided faces and if all of these four can grow you can make a larger up the heat high of why you have four of them OK you can only have gross alone for the rest of all of them and eventually they are going to generate this tetrahedron So you have see this kind of without wishing in terms of symmetry and this turned out to be related again to the kinetics of the without wishing for the precursors one of them was reduced the relatively slowly you have this little reduction for this case but this one you have very quickly and the reason you how quickly the action they have simply read that she knew it was that was their concentration became very low and then the Adams vailable for rose suddenly is going to be. Lower than you quiver the sides on the seat so that's why only half of this sixty eight side if it would be able to grow and the other four would be just automatic shutdown generated this particular So here's another example that's also interesting in this case the wrist the other way is that behavior of seats are shown over here and we're shown a long time ago you can have a way to elongate alone the actual direction of this seat and eventually you can generate these so-called to wind. Noise that could be useful form an applications and then a few years ago when we look at this problem again with other ways of different type of seats we use the Palladium seats instead of using silver seal was terrible you don't know you are symmetry was a pro can OK you cannot really tell you cannot do mapping and figure out of the symmetry by the one with switch to Palladium seeds and also switch to a different the precursor this is going to be reduced pretty slowly on that they spend the conditions we use and then afterwards when we analyze this nano rods or nano wires if longer and refund something interesting basically this seed is a good to be located at one of the two ends it's not in the middle point OK of these rods it's always going to be located the one on the ends of course so again it didn't this process the symmetry was broken it's not a corner from both sides just a skull with one of the two sites and stem is also true for another system when we use Palladium seeds and the grower for the gross of copper archery Finally for this and the rot and we are protesting that the seeds again is going to be located on one of the two ends not in the middle OK so it's symmetry was against him it was a broken down in this kind of process so here is the most recent example OK here's another way or another type of symmetry. Or symmetry a bridge in this is kind of a structure with. This is kind of like a horror show interior and that in the Soviet saga Sophie's is going to be symmetrical to each other in principle even though the environment a might be slightly different right by the overall use thing that is going to be a symmetry and the one with deposit or some more Adams onto this particular you can have deposition on the outer surface only or maybe on the outer and in the surface so again this is a going to be a more or less like a symmetrical rose. Out in the face and this is going only have grows on the outer So based. On the in the surface the symmetry was broken in this case so the question is can we really control and to generated this type of structures selectively OK and turned out to be possible again we look at the reduction kinetics if the precursor can be reduced very quickly into Adams and this Adam's tend not to be only deposit on the outer So they have no chance to diffuse into the interior because once the atom get through very close to the surface bone dry are going to be deposited on the surface unless this precursor cannot be reduced very slowly and they can have a chance that they fuse into inside of this hollow structure and then being deposited and in this case the outer side in the side is a going to be more or less equal to each other so you can preserve the scimitar So it's a kind of like a you need slow reduction again faster with action in this case that I'm sorry and then you're going to be able to preserve the symmetry if you have a faster without wishing you're going to just get the symmetry in this case so we'll use this go on OK just to do this experiment for one of them where use this precursor of the impetuous call right that can be reduced to read three quickly and then we have another arm come to a pot that's a political head to a brawl might be reduce the slowly and then after deposition we can analyze the change of dimension that in the channel check what the management. And out to the dimension of this and then a cage and then here is the prologue this green bar shows you the thinking this of the wall for the all region the Nano cages and then this is a brew one is the thinking this of metal you deposit on the altar so face and this is red a second one indicates the matter you deposit on the inner surface and in this case it's going to be symmetry broken OK you only have deposition on the outer surface but this is one for this precursor it's a slowly reduce you won't be able to generate the symmetric on the outer and in the surface OK so you can see again very clearly here as on the rest T.M. You can see this is a symmetrical structure you have gold in the middle you have Palladium on the outer and inner So face but in this situation you are going to have put it on the outer surface only very little on the in the surface so again you can see the symmetry could be preserved all broken OK depends on the experiment the conditions in this case is I'm in the reduction kinetics of the system so what I have shown your so far mainly based on what having a systems so you can fragment even before we look at this system we also look at the hybrid systems in this case we have a polymer being deposited on the metallic nanoparticles seeds and to form this carload the sphere us and we find that doing the part of OS tiring to make the poorest are in beads at a certain point after the initial. Thought of choroid and we find that this porous star eventually can only be nucleated form a small patch regions and thought a surface it's not going to be on the entire surface of the boat and this part is starting again can be increased in terms of volume as proceeds and eventually it will form this kind of interesting structure of the seed that go to seed is a going to be sit at one side of this in the other going to be in the center OK. And here to show you some T.M. images you can different sized goal nanoparticles you can see you have this gold located in the center of the particular alright and here are some more examples of all this and this is based on the solution phrase our procedure so that means you can make a logical in that it doesn't there are really no limitations and this is basically a back scatter S.C.M. scanning electron microscopy which So you can see the it's particle Where have a code inside by the not in the center is it going to be opposed to the edge and here you can see this part of the actuary is not exactly inside of the porous downbeats is just slightly imbedded into the surface of this particular So that indicates there is. A sun at night as you were given some of this particular. Tree for study and how this particular way I assembled because this particular shown over here could be called the platinum palladium they have had a little properties so you can trigger how they are going to move when we add a sum for us in the system anyways the interest of them so finally let me show you another example this is like a you make in part because with some more poor tree in the SO face again it's not a symmetric it again right is not in the script of symmetry and then more and to make of them is also simple you took some lively cross link it. Beats with swelling and with solvent the like appalling So make a larger particular and then we freeze dry it and then we landed this is solvent evaporates on the vacuum conditions and automatically again they change their symmetry to this point it's like a streak of symmetry OK but when we have your valve which is like a volcano you have proceeding in the symmetry is automatically broken again so you're going to generate a small hole on the surface and to form this kind of particular And here just show you some examples again of. It is another go to particular this is small boy this is estimates not the T M A M H T M image and also once you have formed there is no particular you can lead this small hole to be closed if he did that. All close to a deposit on the temperature of the polymer So they're going to basically start to close up and eventually about Chris of a come completely OK but in this way you can control the size of the opening OK And also the voids inside there's a particular and interested you can lower the inside with something in this case could be sodium chloride a solution and then you lead them Crystal out OK form this a little pot it goes inside and once is complete the crows how to go supposed to have over all the symmetry but if you look at the interior structure is not the screw the symmetry OK it's going to be given the symmetry OK A You can also have liquid to be included. Eventually become sorry the particles in this case could be just the PO for a column this kind of liquids depend on how much you edit you can also have different degrees of feeling and you also have a some interest in particle B. This kind of interesting overall spherical symmetry but in detail it's not so symmetrical in a sense so I hope I gave you some examples OK how we can manipulate also ensure the symmetry of nano particles in their fabrication awesome this is a process and the fault metallic nanoparticles basically. Like a criteria you had to observe first you had to make sure you only have he did units nucleation and this Adams only nuclear on the surface of the seeds otherwise you're going to do have a homogeneous nucleation it's going to be out of control and when you can only have he did in his new creation you can control the number of Adam's been generated basically you can control hum in this side of. Of will be involved in the new creation the crows and then in that case the symmetry can be reduced to or broken at the end the specific a pattern you want to have and of course you have today made the surface deficient you can imagine even you have a symmetry breaking in the new critical stage with this Adam combined with freely easily on the surface of course they would like to populate the other side so the symmetry would be preserved instead of being broken so basically all you probably need to keep the temperature obvious and this is relatively low to minimize the surface deficient of atoms but in a way I hope. You have some interest in this particular if you find any use you can send me emails more than happy to send you some sample to study and find that it doesn't run to the knowledge of funding agencies. Of course this funds play a very important role in my career there have been over the past ten to yes and that's why attention to having to answer questions thank you.