Hi everyone from a score of chemical engineer. Today I will talk to. The emerging material for renewable energy technology. This is my Ph D. professor Chris Jones discussed the surface modification of a specific type of nano tubes which is three K. nano tubes and the composite member and fabrication using specific nano to the applications. OK OK let's start with this suppression is critical process which represents thirty to seventy percent of the cost and conventions of the Persian technology lation has intensity to address this issue membrane suppression technology has been developed to lower the the energy input. However you see pure polymeric membranes for separation this usually suffers from a trade of between per Bertie. Regarding such an imitation our research group has been working materials. Or made whole organic works which can effectively incorporated into a membrane separation process. Hyflux at the same time I'm only. No tubes are unique due to the one dimensional not one dimensional geometry and higher spec ratio of four possible. Alignment members. But before we jump into the sea tongues of member and said test them. We want to first convince ourselves how much we can get with the nanotube membranous. OK so we performed mass transport modeling to evaluate to Representative type of nanotube membranes the first one is so called Think. In which the member thickness is March larger the nanotube legs. The second member architecture we have considered the membrane in which the member. Is about the same or smaller than the nanotube links. So the normal team can spend across the member and serve as the direct message transport. OK Our modeling results suggest that if we used not your membranes we only marginal improvement in terms of Bertie and select committee. However on the other hand out of the known two membranous could give a significant improvement in terms of probability and selective U.T. OK. Therefore this membranous is a desirable type of not a member and that we are going to realize this gives me a strong motivation for my whole period. The study to realize the membrane architecture. However to really apply nanotubes to large scale separation units there are many issues need to be addressed down the road. First of all there are many types of. Not all tubes which one is the best candidate and how can we control the knowledge of dimensions into a surface to tailor its intrinsic properties and finally how do these type of ideo nanotube membranes. In the following told discuss our key observations material selection of the nano tubes the emission control surface mount creation fabrication. Let's start. Speaking of nano tubes the carbon nanotubes are perhaps the most well known type. It has very high in the facility for for many different species. And it is advantageous to separations. However if this is caused to make them not a very good candidate for any large scale separation units. Additionally it is very challenging to functionalize the interiors surface of carbon nanotubes with bunks because ordered to do that the carbon atom need to go through the S P two P. three transformation this transformation is entered called the unfavorable concave surface carbon nanotubes the limitations of carbon nanotubes the third hated the discovery the research. Nanotubes or tubes hydrothermal the or silver some only were last years is cost and it is relatively easy to functionalize the interest surface of metal are. Now too. More different types of metal oxide nano tubes. We identified along most of the tubes promising candidate for separations the researchers discuss in the following along and also you can use one part the most serious is and it does not require a template. Factor. It can be serious sized moderate serious is conditions Thurston's cost is much lower the carbon nanotubes to product after purification shows very uniform. Morphology the atomic model of the interior surface is made of the current hydroxide and serve its outer shell as made of aluminum hydroxide hydroxide group can serve as the active sites for the interior surface modification which will be discussed later. OK And then we performed a simulation is to evaluate the intrinsic suppression properties of aluminum tubes. You see molecule pair. OK study in this case study you were looking at two parameters of the first one is severity and the second one is water to. Selective. OK the simulated waters the water depth of thinking are tubes such as. It has a single ward. Carbon nanotubes much higher in comparison to the similar frameworks and pore size with a nano tubes on the other hand this knowledge tubes has very high water. Very likely due to the high drugs group density and its interior a combination of severity and high makes a very good candidate for your cation and if we care if we can potentially functionalized surface of the snow Tube we can potentially tailor its intrinsic properties to make it suitable for our systems. OK After discussing the material selection let's move along to the dimension control of these now tubes. The reason for to mention or come true is that we want to be able to engineer the time mentions of tubes and make it four different separation systems. But the key challenge here is that people don't quite understand the senses mechanisms of these specific nano tubes. And we need to so we need to first divert make me seek understanding of Sirius's before week and manipulate its dimensions. Let's first talk about the experiments. If we use different acid Aleutians for this week and our meters. More specifically. Stronger as the. Larger in the US The question is why. To answer this question we first performed. The No No two precursors solution since. We don't use the structure optimization to identify the species spectroscopy. And we far out for most species. There are coming from the acid at the ends of the precursor Mark Hughes and unexperienced choose from the acid seems to have a strong correlation to the precursor curvatures. More specifically the air and I are from stronger as it gives a lower degree of curvature of the species giving a larger knowledge of meters. This is a possible mechanism for determining Now let's move along to the length control my previous colleague used alone recorded to T.M. images of his tan that we want to divert correlation between the known to Billings since his conditions to make a more quantitative analysis we proposed kinetic model for an assembly includes two steps the first is creation which which describes the transformation of precursors into the smallest unit. Then the smallest unit can either collide with another precursor or can collide with another piece of no tubes for growing and ultimately we found out the predict the model prediction of quite a world not have links to its distribution far out in the experiments this model week qualitatively predict the nanotube length. The function of Sirius is turn at different condition in the show precursor concentrations. In other words the longest is term or the lower initial precursor concentration would give larger blanks. OK after talking about the time mentioned to mention control of the knot Tube So let's move on to the next topic which is interior surface month creation and all work is the first successful demonstration that the organic warrantees can be mobilized. At the interior surface of single ward nano tubes with the Surface mount acacia significantly improve its activity for carbon dioxide. And we have devoted to different approaches to interior month creation. The first one is supposed Sirius is from shows Asia and the second one is direct functions Asia first post this is functions Asian pulses post see if those functions function as they should we first know tubes. We compare now to drug side interior surface. And then we age and to react with the series drugs like groups. However you may as you may be curious the surface modification of the drugs new idea people can play a play selling chemistry. To treatment drugs and surface. So what's the number to hear. OK And what's unusual about our system is four of four of our first few trials with Agent we pretty much got to zero organic loadings the interior surface of these now. We do you what's going on here. In the unusual thing about this material is that it has extremely high density one anime Terk confinement. And this high such high high drugs density results in strong water and stop should be in conditions tries of the strong surface binded water needs surface functions zation from happening. So in order to functional ice into a surface of the now two we need to first remove and solve the water so to do that we study to figure out the temperature that we can completely remove the water without its structure. And we use several different temperature dependent techniques to perform that you have to study. For the interest of time. Our only show you the results from in situ Exidy you would present I think the most interesting one. OK An Exidy is well known for characterize the periodical structures for solid state materials and how can it be used to characterize or to quantify the water loading. The idea. The electron density contrast or determining the intensity contrast in the Exidy patterns. The hydrated the nanotube field with water have very different electron density contrast in the materials. OK which would cause different. Intensity contrasts in the Exidy patterns. Showing simulated Exidy patterns of nano tubes with different water loadings specifically. If we remove the water from the now tubes. We can see the higher intensity of the first peaks. And a similar trend is experimentally you see in situ X R R D experiments with temperatures. OK Here we see when we increase the temperature of the vacuum. We can see the first peak in ten tensity monotonically increases up to fifty degrees C.. A combination of experimental Exidy patterns and simulated Exidy results allow us to qualify the water loading in a nano tubes. No qualification of the studies agrees with curves in the sense that they are both just to fifty degrees C. We can completely remove the water from the number two materials so to perform the interior for functions they share and we first pre-treat to fifty degrees the vacuum to fully remove the water and then we introduce really agent force into surface modification. So far for examples comes from three different regions as stock or I'd try to silence. OK this proposed reaction schemes will be supported by the following studies there and then mark across the nation. First of all for functionalized nano tubes. We see top peaks in carbon and then more spectrum coming from coming from the groups as well as the groups and this has introduced a real agent has being immobilized on the surface of the nano tubes for the current and the must read from we don't see a significant change when the surface modification because this reaction will not affect too much come from Orcs and for those trying to cross functional lies down the tubes. We use an M.R.I. to characterize chemistry because these three agent. Species thought you were introduced addition knows. So you can for more to the nanotube systems. Experiment or spectrum we see the Tier one Tier two Tier three peaks. Corresponding to the monarch then tape identity and trade then pay species coming from introduce reagent So this proposal reaction scheme could be supported by silicon and their mark across the nation very similar idea for Coke arising the myth functionalized one or two things least reagent contents both silicon and carbon species we use both carbon and them and them are to the material and the pigs both and they must better on are consistent with the proposed reactions perswade OK so far we use them are to demonstrate that we do have the desirable species on the surface of the now. But we are not one hundred percent sure they are immobilized the Interior or the external surface of the nano tubes to answer this question. We combine two different techniques the first one is and the second one is every metric nurses T.G.. The nitrogen faeces lotion tells the poor Valan of the now. You can give us an idea if there is any seeing immobilize the surface of the nano tubes. OK. Not sure if he is ocean are I saw thermos we see the uptake of the functional now tubes are lowered the tubes that means at least some of a portion of the introducer agents are immobilized the interior surface. OK. And then we qualified the organic Lodhi from. Measurement measurement integer measurement. We basically increase the temperature to burn of the organic grooves interior and external surface to give the total getting in on the materials. OK. Here we've got the Quantified organic loadings from these two techniques are fairly close to each other and that implies put in March or introduced organic species or immobilize the interior surface supposed to the external surface of the tubes. Since we already know there are organic wired he is immobilized and in two surfaces we use water as option to evaluate the felicity of the functionalized now tubes. And here we see three functionalized nano tubes polls shows lower water uptake in comparison to the tubes. This means with surface modification we lower jaw. Felicity and its effective approach to engineer is the felicity of materials. OK after talking about Poles This is from his Asian Let's move on to the next approach of the of functions Asian origin direct from sensation. The idea is that we substitute organ or silence to hear us which is source for making nanotubes. OK. Ideally we can do partial substitution or we can do a fourth substitution. Bird so far we can make twenty percent substitution of amino mess. Nano tubes you see I mean no mirrors see the silence. OK And Ford for this function lies now to perform a comprehensive solution for determining structure and surf chemistry and for the interest of time. Our only show you see an M.R.. In the T.M. images of in our tubes and the twenty percent substituted I mean no not tubes. They both show uniform morphology that means the twenty percent substitution does not affect the moment. The dramatically change the structure. Now in Kern and them are of twenty percent amino not to the peaks the peak at minus eighty ppm comes from the sense you come from work because it's only twenty percent substitution. We did some control experiment in order to fly the miners fifty five pm we added maybe two three six for morgues and two people who are not for mere words studies there are no more terminology. The three here means three out of force the components connect to the drug zero or species and the six alone here represents that. Kirn this connects to see through. OK this type of framework is the fingerprint for more of a luminosity and it demonstrates or introduced. I mean no mere thought silent has become part of the framework into a function zation successful. OK now let's move on to the measurements of functionalized nanotubes First off or we see the nano tubes which is twenty percent and I mean groups has march to to Mr selective A T in comparison to nano tubes functionalized not Tube also has march up to ten times improvement in terms of C O two to hear it in comparison to. This is significant breakthrough. Of technology because it basically demonstrated that we can turn to your waist nearly no C O two selective A T into a promise the candidate of or separations after talking about interior surface functions ation of tubes into a composite member or fabrications a sign introduced in the very beginning we consider two different. Membrane architectures think membrane and the outsourcing membranes the trade of think not to remember is. Are easier to favorite but it would only give marginal performance improvement where we are told thing to remember and it's are difficult to make but it could give first very high performance. OK So while we decided to do is first very Cade think now to membranous and then we translate the knowledge we learned here to to fabricating The membranous OK even though the think not only of membranous are relatively easy non-trivial because if we review what people have done for making carbon nanotubes portable compasses membranous they either show poor interface show and he should or they show severe. Both are in desirable for separation of locations. OK So to address this issue we carefully choose Palmeri for for blending with what we chose here is poly P.V.A. because it has lots of drugs groups. It could and it is hypothesized to interact well with the external surface of the now Tube because it's also covered by lots of hydroxyl groups. As a result not here. P.V. come possibly members where is forty one percent knotted loadings uniform membrane suggesting the dispersion in polymeric metrics. Here we look at. No C.M. images of one or two people become passe membranous was different. And here we are the cross section basically look very homogeneous and we don't see micro scale defects. However the resolution of these as C.M.E. is no higher nerve to see the nanotubes but we can demonstrate the presence of the now tubes by looking at the slice scales look at the ratios. Here we see come to carbon ratio the increases the increases. So just the presence of the now tubes in the composite membranes. OK. And so far we we don't see a scale now to do we want to we want to be able to know if meters kill the nanotubes disperse individually or day for very small bungles. Specifically we want to know in the bass remember and if the narrative dispersed like this or they actually form small forms more poundals that are not seen in the C.M. images. We use X. already to this question but before we before I show uniques the experimental Exidy result I first used the simulation is to tell you what to do we are looking at here. The X. are the parents of now tubes are very sensitive to specifically if they're not have dispersed individual tubes the parents like this. OK And if if it starts to form small bungalows like for not have bungled. Those patterns will look different. Specifically you will start to see a shoulder like peak like peek out five degree Tuesday. Now if we take the Exidy measurement of the composite membranous waist deep for a narrative loadings we don't see the shoulder like pig except the Nano to the composite membrane samples with the highest loadings OK And this base you suggest that members for the members that we prepared. Not know. Not to use dispersed individually as opposed to for me. OK this is very good dispersion and is advantage is the advantages to separation applications. Now we use water as the pressure and to evaluate the suppression properties of the passive member instead we made. This is set up where we placed no tube capacity membranes in this many fold and one side of the membrane is income take with the water as the mixture and we pour back in the underside. And we use the liquid nitrogen chirps to collect permeate product and the lies seeing the premier product we can quantify the water per bird water to as no selective. Of the made membranes just a quick reminder of why why do we want to be why do we want to incorporate no tubes or membranes for water as no surprise since the reason. It is our simulation is just that there is no tubes have very high water to facility and it also has very high water to the whole selective ity so by incorporating is not into membranous it could potentially increase or improve its performance told results are summarized in this slide here we see the water bird he increases increases which may be agree with our model prediction. On the other hand. The water to ethanol selected he drops quite a lot. When the now to blow the increases and it does not agree with the predicted acuity. And or hypothesized is that the strong surface interaction between the nanotubes and. The P.V. metrics could impact far G. and. Potentially caused the loss of the water to as no selective it. OK To test this our past is we and carbon thirteen size the N.M.R. to the P.V. a morphology by P.V. in morphology what I mean specific the crystal heard of the P.V. metrics. As we know P.V. A is a semi create Salima tree contents both more first domain and creasing domain. And we hypothesize that by introducing the nanotubes into the matrix. It may it may altered the formation of the faces. The reason for that is strong interaction between a polymer chains and the external surface of the limo C. Kader not you. OK And we perform the P.V. station you see the to quantify the degree of Christianity of the P.V.A. metrics we use to experiment to quantify the crease thought or mean size of metrics here I show you a share using X R D. And here we see with incorporation of nanotubes we see lower and lower degree of Christian earthy of the P.V.A. metrics which suggest in the presence of nanotubes P.V.A. has it's more it becomes more difficult to form the crease Soli domain of P.V.A. and this is part of reason that we see the low water to as selective a T. in the presence of the. Said current experiment we did was contact an experiment using science and M.R. and the idea here is that we collect C. certain carbon a mass spec trunk. Here we see two thirds of the peaks coming from two different carbons of P.V.A. we recorded the pick. Intensity as a function of the cross proposition term we see we see a curve like this and by fitting the experimental result we can extract release. Couric restate parameters. Called Tier one role protocol and the physical meaning of. Is station transfer turn. From the crease Olindo man to the more dominant. So the smaller proton represents the smaller crease all the face domain of the P.V.A. metrics and here we see in the presence of the now tubes. We have a smaller proton which means the presence of the now tubes suppress the formation of men and it could also be part of the reason is that we see lower water too as no subjectivity incorporation of the nano tubes. OK after talking about the fabrication of the sake not of membranes Let's move on to the preparation of our trust signal to members. The reason want to predicate these type of remembrances is that for our modeling suggest that this type of membrane is significant improvement in terms of Bertie and selected. OK not to mislead you. This contour represents the idea of. The idea architecture of the membrane in which or every single large tubes are perfectly aligned. However in the presence of the driving force for align The membranous it could be the now tubes could be randomly oriented. OK the way we fabricate these types of membrane is that we will drop cast of very tile loot P.V.A. now to. And to Polly probably support. With that we can form a really uniform the nanotube members on the top of poly probably. Support and the thickness of the membrane about three hundred nanometers the average length of the knot tubes. Eight hundred meters. That means part of the now to spend across the membranes and serve as transport channels. OK this is still an ongoing work. We're on the way to characterize the orientation of the nano tubes in a membranes and we are testing. Performance. So I apologize for not showing you more results of this work and I hope I can show share it is in the near future. OK To summarize this work. We identified the promising materials for large scale suppression process because it has lost this is cost and high intrinsic separation perform properties. We develop and semi connotative models to predict now two rulings in different senses conditions and we diverge two different approaches the post is function station and the red function station. For tailoring inside of Felicity increasing. C O two selective and finally we successfully prepared. P.V.A. now too cumbersome membranes with good knowledge of dispersions for hydration. We are on the way to fabricate the our trials the membranes. OK And some future directions from this work includes first into more work into surface function sation and here we only have twenty percent of organic loadings and we see a significant improvement in selective it. So if we can increase the organic load the we could potentially increase for the increased molecular and sort of selectivity. OK We're hoping that we can other than the amino groups we carry mobilize different functional groups and interior surface of. OK. And the second filter direction is now to Palmer capacity membrane fabrications. Here we can only favorite Kate. We can only play and the now tubes because the external surface is very filling. And if we can potentially functionalized the external surface of these now tubes. We compared lies are dirty from polymers and making many different types of now to come past. OK This work is supported by Philip sixty six and I want to thank my collaborators Dr G. Dr Dr Lee Dr used to learn along to acknowledge my. My thesis advisor Professor Shankar and Professor Chris Jones the group members Research Group. Sure thing. Two to my wife who is sitting there with no scientific back rolls but she has fallen asleep yet. OK I'll be happy to take any questions. Thank you thank you so you mean the difference between the mark you go through and now tubes and go through. Yes I see so what do you know to do that. Actually if if you just use the Pollie Murs to make the membranous It's like structure that you suggest but the idea here is that using the inorganic materials we can have a more well defined pour size we start we can have more control more control facility selective anti your second question if the diameter affects the city. Yes it definitely affects the city. And it affects us of a selective A T in different ways. If the diameter is small enough it will cause a saving effect of the molecules. So if that's the selective it comes from the size exclusion effect. OK but if the port diameter is much larger than the molecules that we want to separate what dominates the interior surf is chemical properties. OK so the mechanisms are different depending on the timing that you you look at yes sure. Exactly. Yes several groups several groups including ours has the injured take relations of the narrative structure. OK and we fall out if we part the average energy as a function of the number of repeating unit. We can found a minimum. OK. I mean if I remember correctly the minimum is like thirteen or somewhat here but the the energy of eleven and fifteen are thirty six. So this is the. Thermodynamic standpoint but this model provides can take standpoint of how the deter me so I believe there are two competing effects here. Right. I see details of this wild assumption I source arms by looking at the low pressure reach him and feed the dead how with the models which describes the more he layer at. What we found is the lower formation into surface the functionalized has active sites for water and income person too. In other words if the hydroxyl group is occupied or substituted by the organic species. Some wired the active side for water. But for the second for the second order higher layers. It's about the same. Because I think it's because of the scale so they look. Yes. This one. The thirty three is the ratio of the C O two uptake the C O two adsorption quantity and the methane as quantity pressure. Right. The concentration of the pairs is interchangeable with the pressure. So in other words the X. and the X. coordinate the concentration of the gas they are interchangeable pressure and concentration are interchangeable. I see so. This the third highs are actually taken from a single component assumption. So we perform these two and solve separately in the data. And we can certainly do make scarce and the results may or may not be the same. No not yet.