Hi everybody it's Sam at mixed up craft thank you for watching my tutorial today I'm going to be showing you how to make these fold flat gift bags I do love making these I have a whole playlist dedicated to fold flat gift bags in all different sizes so every time I do one I try to change the size and what I'm going to do is I'm going to write the sizes within the title so when you look at that playlist you can go through see all the sizes and decide what one it is that you need to make depending on the gift that you have to go in it. These are lovely I actually made a slightly different size for when this was launched for trim craft because I'm on the design team so I've done this style and you'll see it featuring some of the actual you know photos for this collection and I just thought it was such a nice way to show off you know the frames and all these other bits and pieces so this is using the dove craft happy you collection and these are photo frames but they work so well as handles now I have done these handles like this for the quad box that I've done again I'll share that up here because that's another really nice tutorial but I just think they look great so that's them folded flat and you can see now how roomy these are so these particular ones measure seven and a half in height seven in width and four and a half in depth so it's a really lovely size there great in Christmas papers they're going to look really nice under the tree you could put a big bow there to kind of seal it up if you wanted to but I'll just put some tissue paper in there and that will look lovely and then I've got here a little paper clip the bow and the word smile and I think they're really really sweet and then the whole thing just folds nice and flat so you can make a ton of these and store them all away which I know a lot of you like to do so let me show you how to make it okay so I'm using these are the you get eight photo frames okay so I've got two left for today's bag then these are the paper clips I had two packs and I've just this one you'd get three of each design but that was one left from the other packs so I just popped it in there so I'll be using that there the bows so they'll get used and then that's the lovely 12 by 12 paper pack I have two but between the two now yeah I've probably got one paper pack so beautiful papers level the rose gold foiling so for this one I've already got mine here I'm going to use these two now I'm not using a foiled one for the tutorial because it can it kind of plays up with the the camera focusing sometimes plus it's easier for you guys to see the score lines on this one all right so you want two pieces of 12 by 12 okay so make sure you've got your paper if it's directional it's facing up the right way you're going to score it seven and eleven and a half then rotate your card stock and score it four and a half and then score at six and three quarters okay then rotate your card back again so it's in that original orientation and you want to score it nine and a quarter down to that first score line okay and that would have been the six and three quarter one that you scored there okay so if I just bring that up there's that score line there and it just meets with that six and a quarter one this is going to be our back so this is what's going to fold completely flat then you want another piece this is the front so again make sure your orientation's right you're going to score it seven and eleven and a half rotate we're going to score again four and a half but this time you want to flip the card over and score at six and three quarters pass the first score line down to the second score line this is the front we don't want to do that fold flat score line all the way across that front piece we want that to stay nice and intact really you just want the score line so it folds flat to be on both sides and the back which is what we have because this is a side piece here okay so that's all the scoring with the scoreboard then I'm just using a stylus and my metal ruler and you just want to add a few extra score lines I'm actually going to flip my nose so it's easy for you to see but you're going to be scoring so imagine yours is that way this section here where you've done that score line just down to that first piece we're going to do a score line from there down to the bottom left and there down to the bottom right those of you that do these fold flat gift bags you'll know exactly what to do and once you do them more and more it's very straightforward but this rectangle that you will have you want to form a triangle within it okay with the top of the triangle meeting with this score line here okay so I'm just going to do that one here okay and all that's going to do is allow or just help the back fold flat so do that again on your second piece this is it here you'll have that same rectangle all right okay now you want to fold and burnish all of your score lines okay don't worry about trying to fold these ones here and this one here but the one where you have that extra score line going all the way across there because you'll have two one this one and then that one this piece here so we've just burnished that one the next one fold back towards you so you've created a valley in a mountain and basically that's how the bag will fold flat so that's the back and that will be in its folded flat position okay so now we need to do a little bit of cutting so again I'm going to keep it up this way so you can see what I'm doing this is the half inch tab all along here and you'll have this four and a half by four and a half square it's this little piece on the side here we want to take out completely okay like so and then just cut nice and neat up this one here this is our base okay now this four by four square we just want to take a couple of wedges off just so that we don't get anything hanging out that we don't want like so and then I always like to take a little wedge off of each end of my tab again just keeps everything concealed okay now you've done that you will be able to fold this piece better so what you want to do is fold that line down so it meets the top of that triangle and then this will kind of just do its own thing it will want to fold that way because of where we done the score line so can you see now how everything's starting to go imagine that's all folded in and there is the back of the fold flat okay so we're going to do exactly the same on this piece so you want to remove that tiny piece we then want to cut up that other one so you've got that four by four and a half sorry by four and a half square nice and free take wedges off of both sides these little ones here and then again with that one bring it up so you just fold it down to the top of the triangle and as you bring this up it will all fold okay so we've got our two pieces ready now if you're going to do the handles like me because that's nothing you don't have to do the handles like this and also if you don't have these frames get your square dies or your rectangle dies and make your own frames I've seen lots of you do that so don't you know don't feel that you have to have these but also you've got these ones these are dovecraft as well and these are the iridescent photoframes and these are the ones that I used on that quad box that I am spoken about really really good so if you do have them lying around or you see the many of your in your craft shops you know yeah use them right before we stick it together we need to stick these handles down now there's a couple of ways to do them so what you can do is you can you basically fold that in half or I will just for the purposes of the video you're working within this section here now it depends how far down you could come all the way down here so your hand goes quite into the bag I like it about there about halfway within this square piece here now if you want you can draw a pencil around that and I think that's how I showed you in the quad box so yeah you can do it that way okay or you can do it the way that I've done it for this which is fold it this way I'm going to lay it over the top here get everything lined up with my grid okay and then I'm going to lay this down make sure I've got it in the middle like so and I'm going to draw a little pencil mark on there so I'm just showing alternative ways to do things because we all find things you know easier or harder to do so I thought if I show you both ways to do it then you can decide so then I'm going to grab my they will stick together in my red tape and then I'm just going to run strip down there you don't have to use the red tape but this is very very strong and I thought because it's a handle you know I want to be sure that it's going to hold I mean not that I don't buy heavy gifts but most gifts are not very heavy anyway so unless you're buying drink or candles majority of things are pretty light okay now before I stick it down I'm going to bring in the other one and just lay it on top slightly offset so you can see the black line underneath and just do the same lines okay I'm going to stick that one in a moment okay take all the backing off then I'm going to pop this underneath I know I want it there because I'm using my grid underneath and I know this will need to line up this is the the start for me and then it's there because it's seven inches so I'm just going to bring it up make sure everything's nice and straight because my frame is because it's on it's already lined up on the grid and just stick that one down okay then flip it over and then I'm going to cut it with my cutting knife now the the reason I'm saying you can do it this way as well as the other way if you maybe don't cut very straight or I don't know you just don't line it up so well you could stick this all down and then see but sticking out whereas if you stick it this way straight away and then just cut it out you know you're going to get a perfect cut so I was using the ruler to try and protect my fingers because I don't like I don't like doing it but I know it's a a good way to do it I'm just going to pop that there there we go and it just comes out and then if I bring it up this way it also looks very neat from this side whereas again if you're cutting it and it goes a little bit skew with you're going to see that well I say that if someone is really kind of you know I always say dissecting your project but I just think that way you do get a nicer finish so you want to redo that now exactly the same way on this one because you've already measured them and put the little pen mark on there you know you'll get everything lined up so I'm just going to speed it up and get this one done okay so I've just gone and added some double-sided tape on my tabs I've taken the backing off of that one already when you're doing gift bags always work from the bottom base score line get that lined up and then work up if then your top is slightly off you can trim it you know it's an easier doing it that way it's easier to be able to kind of save it if it is slightly out whereas if you start from the top and come down playing around with the base is just going to be a bit more of a hassle so it's easier to work from the bottom up if you scored everything you should be fine you can see there see what I mean I am actually just a tiny bit out because that is so so small and I think it's just because I come a little bit high I can just come in underneath and just very carefully on and you know kind of follow the the angle really there we go you'd never know okay and then fold oh got a static all on me fold this half over I've just taken off the the backing there and then bring this one over and again start from the base so you will have now the front and the back and the base the front will be the side that's perfect you won't have that extra score line but on the side you'll have that score line that should run all the way around the three sides here okay so have the back facing you so there's that score line there you want to fold that one down first and then I'm going to grab my boot and I'm going to stick one of the sides down first again like I always say if you do want to make this stronger and reinforce it what I would do is before you stick this down is put some grayboard or a couple of like strips of or pieces of cereal box something like that so then you want to stick that side down just pop that in there so it sticks and then pop some blue on your other bring that one up again fold the whole thing over and you can go in there just take a few minutes just to make sure all that glue is spread out before okay and then I am going to bead of glue all the way around the sides and then you can just bring this one down and just go in there again and just make sure it's all stuck okay while that's drying I'll just show you what I've done with the little piece here so you can decorate with anything you want and use little charms but I'm using just the plain ones because I have all of these here which I fussy cut from one of the sheets in the paper pad and I'm using smile on all of them I just I like that one so yeah we'll go for that one so I've got one of them I've got oh they do have foam sticky on the back but I'm going to be using my hot glue gun as well so I'm going to pop that in there like so okay so I've got those pieces there and then you now want to push your sides in which you would have already scored and then just start to I've kind of pushed those my fingers are on the top of the triangles okay and then these ones are here and just kind of push it in it will kind of pop it will look it kind of pops in it just knows that it wants to go that way and everything will line up perfectly and just go and burnish it so it kind of gets used to being that way okay you don't want there to be anything overhanging the sides here and stuff that means we've got everything lined up and then we can just decorate it so it's just easier with this because I'm using the hot glue to do it when it's all flat so I'm just going to add a bead of glue there and also just to kind of seal all that in there as well and then I've got it just coming off the corner so I don't know if I've got a happy you playlist actually I've got the secret garden playlist which is the other one that we received the same time so I will double check and I will add it in now if I do because there's some lovely beautiful projects there you have it how cute is that they have it three beautiful gift bags honestly this took half an hour to do all this it took no time at all I think because the handle's already done you know all this is done all you've got to do the time consuming bit is just cutting out that scoring and folding and stuff it's very very quick so if you do need quick bags full flat ones are surprisingly fast it's just the decoration that would add more time so hope you like it if you do please give me a thumbs up check out all those playlists because there's so much inspiration on my channel please subscribe if you haven't already and I'll be back again soon with another tutorial thanks for watching bye


Who I am, just really quick, I'm a software engineer as chef over the last six months. I've been focused on some inspected related projects, compliance, kind of things. And what I'm going to talk about today is just a little bit about infrastructure testing, and then I'm going to show you some really awesome toolings for infrastructure testing. So what is infrastructure testing? Do all of you kind of familiar with infrastructure testing? Yeah, mostly. So it's traditionally done, it's been traditionally done with kind of one-off things manually. Then, of course, all the big management tools have made it easier to do it. But people are using test kitchen, server spec, other kinds of things to do infrastructure testing right now. And it's going well, but integrating that into your pipeline is a whole other story and just making those tests as solid as you can has been kind of hard. So at Chef, we've been working to make that a little bit easier. So I've got a question for you, this is kind of the audience participation a little bit. So what kind of tests do you guys usually do for your house? Data tests. Yeah, right. So you run those tests after you've deployed before? Before. Before, right? So what about your infrastructure tests? Are you running those before you deploy? Yes. Some of them? So we should integrate those into our continuous integration pipeline, right? A continuous integration system. So this is a screenshot of a CI pipeline that we have at Chef, kind of automated. So I just kind of dropped a screenshot of a CI pipeline for this. So we've got our unit test running. And they're running great, they're in the pipeline. But what we can do is we can create something so that we can easily run these within our pipeline and easily run the infrastructure tests within our pipeline and then get a report each time before it goes out so that we always know if our infrastructure is safe or not. Because nobody wants to hear their infrastructure is failing at campaign. It makes it totally very sad. And galley has to get up in the night to fix some galley infrastructure. You're right. We kind of know about infrastructure tests and we like infrastructure tests. What kind of tooling are you all using right now for infrastructure tests? Right. The service bag test kitchen is kind of the usual answer there. So there's been some new tooling in the works for the last couple years. And that's InSpec. So I'm going to tell you a little bit about it. So InSpec is an open source framework for testing your infrastructure. And it's a command line tool. You can do whatever you want with it. It's platform agnostic. We don't care. You can run it. And InSpec doesn't care if you're using Chef and co-public. You can test your infrastructure with SSH, WinRM, Docker. InSpec is standalone and doesn't care what you're doing. We just want you to be able to do the thing. You can test your AWS security groups within the system. So how many of you have had problems with OpenSSL in the last few years? I actually think I saw a post. Yeah. I saw a post, right? Yesterday that there were more vulnerabilities coming up. I think the people were working on doing InSpec for a while, right? He came out yesterday or a couple days ago. So we all kind of came up with our own solutions to figuring out those things. But this is what InSpec example is like. You guys are probably pretty familiar with it. It's pretty easy to read. You've seen this kind of thing with service bag, with RSVAC. It's the same stuff. I'm going to go into a little bit about how we use InSpec. And then I'll go back and talk about that. Because that's just the described block and that's cool. But there's so much more you can do with it. So InSpec is a gem. You just gem and install InSpec. We don't put anything on your production servers. Just run it. You have SSH, WinRM. So it's just a tiny gem you're installing. And you can run it in the command lines if you choose to. With InSpec and Sec. So you're going to get a little bit of an output like this. You're just running describe blocks. You'll see something like that. That just tells you what it was, did it pass, how many failed. It's a nice, easy, simple way to run it. And if you notice, in the last slide, there was a little card there that says target local. So that target local is going to tell you where you're running your tasks. So if you run it against other places, you'll see that the little target changes there. So you can run it against your module, against your set of tasks. Whatever. I'm going to show you a little bit about that. So I, well, if my computer wants to open me, there we go. I'm going to show you a little bit about this. So I set up a couple, provisioned a couple little machines before I got here. So you can see in our vagrant file, I have two machines here. One was set up with the WordPress simple role. The other one was set up with our WordPress. That's our secured and our Ubuntu local one. So if we go through and we look at those roles, you'll see the WordPress simple is just doing WordPress and connects. It's got nothing special. But if we take a look at our secured machine, we'll see that we think did up with a few more things. I'm going to give you guys the links for those in a minute. But just for now, just know that we beefed it up with some other chef recipes to just make it a hardened server. So if we go through now and we say we can use InSpec not only to run the test, but to also check what platform we're running on. So if we InSpec, no, that's not right. Hold on. So if we check on our Ubuntu machine, we're going to see that InSpec detects. You can ignore all those end results. And you're going to see that it tells us exactly what we're running. So if we do the same thing for our secured machine, we should get the same output because they're the same thing. They're just a little bit different with their roles. There we go. Sorry. Okay, so we see that it's the same thing. So now we have in here something called test OS hardening. That's what InSpec calls a profile. But what we're really interested in is just looking at what's in there. So right now if we go into the list out what's in test OS hardening, we'll see there's a controls part. And that's the part we're really concerned with right now. We'll figure out the rest of it later. So if we list out there, there's a few different files in there with some tests. We can check out this first one. It's kind of a big file. So we're just going to take a quick look just so that you know what I'm testing things with. So you can see in this file we've got some Etsy groups and password-y stuff. We have some login depths that need to be defined. We're making sure about, you know, execution rights, all that stuff. The articles. And now we can see how our Ubuntu machine kind of pops up there. Because so we're going to run that profile against that machine that we provisioned. And we see that we've got a few values. It's not doing so hot. And we can see these failures right here, right? So we know we've got some stuff going on. If we run it against the hardened server, we should see some different outputs because we took care to actually make sure that one was set up. So just come over here. And here we'll see, hopefully, that everything passes. Because that was the server that we provisioned with all the extra ones. And that's going to take an extra little second here. There we go. So that's kind of my example of how we run InSpec. So that you can see what the difference is and why it's important. Those profiles that our children are going to be looking for, they're there. That's just some different chef cookbook and then an InSpec profile that we have on. One thing about the described blocks. We've seen these described blocks before. So what's so special about InSpec? The thing about InSpec is that it makes it really easy to understand because InSpec has a concept of a control. So a control is basically like a wrapper around that described block that makes it easy for everybody to understand what's happening. You can give it an ID and then you can give it an impact. And the impact is what tells you how bad the test behavior. We're saying if you have an impact of 0.3 or less, it's a minor failure. 0.4 to 7 or 4.6 is going to be like a major. And then 7 to 1.0 is a critical thing. So that way you can decide each time in your test, in your controls, how important this one is. Because not all of our infrastructure tests are going to pass all the time in real world. So this way we can decide what actually stops our pipeline and what just kind of tells us, oh, we need to take a look at that spot. The other cool thing is that you're able to include a title and a description. So anybody who comes in can see easily what this test is for. Because as much as a lot of us can read these tests, a lot of people can't read these tests or don't know why. Or even if you can read the test, you might not know why you should do it. And so including that title and description allows everybody to communicate clearly across the organization because we can tell everybody, well, hey, look at the description if they need to know why we need to run these tests and why it's important. So INSPEC has a lot of different commands. And I'm just going to go over a few more kind of cool things with it. We saw the INSPEC detect earlier. We can use that to check out what's happening on all of our systems. Anything that we're running before we run it so that we know what operating system details we have. INSPEC also has a cool thing called an interactive debugging shell. It's the INSPEC shell. So what you can do is you can go into INSPEC and you can type out the INSPEC shell and it'll tell you anything you want to know. You can run it against a transport tube. So if you want to run it against that provision machine, you just do INSPEC shell dash G, same thing as before. And you're going to find out anything you need to know. So you can check on all the things on your machine without actually running the test if you're just kind of checking out things. It'll also help you write the tests because you can get some help on all the resources that it's going to have. When we've gotten these tests, you can actually decide if you've got, say, a test and you need to just check if one of them passes. You don't have to go through the whole thing of making sure that this one has this impact and this one has that impact. Sometimes we just want to check if one thing passes. One of the things we can do for that is doing a described dot one. And described dot one will pass if either condition passes. So it'll be marked as passing if the SSH can bake, in this case, the protocol is three or the protocol is two. So that allows us to have a little bit more flexibility in our test and it allows us to have some more, kind of, there's more. I mentioned this just kind of in passing earlier. Inspect has a concept of a profile. So what a profile is, is a collection of tests. So you have your file, your test dot rd, and you have a collection of tests in this file. Now, in your collection of tests, that's great. But then, what the inspect profile does is it takes that collection of tests and then you have an inspect dot yaml at the root and that's going to tell you the metadata about the profile. So that's going to tell you, you can give it the name, which platforms it supports so that you make sure it only runs on the platforms it actually supports so you don't get false failures. And you can do, and you can check that profile with inspect checks. You can also bring up a new profile with inspect in it, for example. If we were to inspect in it, you'll see we created a directory there. You'll see we've got an inspect yaml and we have our controls folder set up and inside of our controls folder then is where we would put our tests, for example. Now it's just set up with a nice little example so that you know what to do, basically. But this is where you would modify all the tests and then you could do whatever you wanted to the inspect yaml to tell everybody why this profile is important and all of that good information. So one of the other cool things about inspect having this concept of a profile is that it allows you within a larger organization. Sometimes you'll have certain profiles that need to be run in certain times and we can use the inheritance feature of inspect to describe which profiles need to be run when and actually go ahead and modify any tests that are in those. So, sorry, I keep saying it wrong. For example, we have in the group inspect we have a folder called examples inheritance that just kind of shows us what this does. So as we cat out the example in here we'll see that we're saying to include the controls from profile and what we do is in the inspect yaml we tell them where this profile is and we're going to skip the control temp 1.0 but we're going to set the control for board n.1.0 and impact of skew. So we can modify all of the profiles so that they follow exactly what we want out of it so that we're not stopping on silly failures or failures that didn't matter. So we can say only run it if it's on this, if it's on Ubuntu or if it's on Debian, anything we want. So for those of you that have been using Test Kitchen all you have to do is add inspect into your verifier as your verifier and then you can use it with all of your same Test Kitchen things that you can use it and you'll see that there's a little part here that says format JSON and where that's useful is if you're going to read in those tests and you don't want just that CLI output you can get a little bit better with it so if we do inspect exact inspect exact examples that example profile and then we do a format JSON we're going to get instead of that CLI output that we were getting before when we just run this we're actually going to get a full JSON format and as you can see by the way this has a bit of a different test output that's because we consider tests to be describe blocks and then anything that's from an actual profile that has controls that's a defined control is going to be called a profile sum so the test summary is going to count all the tests in your file but you're only going to see that if you include anonymous describe blocks that don't have that wrapping control but what's cool about this is that we do a format JSON then we can now put it to JSON and we can use it to kind of visualize all those results so if we pipe it to JQ it'll be a little bit nicer and we can see that we have all of our results here and it's a pretty simple structure it's just the version the version one a little beta one here that's just releasing instead 101 Monday and we've got our profiles it'll tell us everything we need to know about our profile what it supports so where this profile should run that way we don't run anywhere we don't need to and then it'll have our controls and each of those controls then because you might have a few different tests in your control where you're going to have all of your results so that's what makes it kind of easy to consume especially if you're working with a build system and UI and you want everybody to kind of clearly see what you need and what's been passing and what hasn't that's where you can kind of use that to just show them the whole deal without them having to run without them having to look at the see a lot of it all the time which is kind of what we did with the compliance server that cost dollars I know that that cost dollars is the most thing but that's kind of what we did with you for those of you that saw when I was running that profile earlier you might have seen some CIS things but those of you that are familiar with CIS so that's another thing that I'm sorry cost dollars that we have an algorithm that we worked on a couple quarters back to translate all of those CIS profiles that you've ever seen as CIS profile it usually has this wonderful XML with these Oval and XTCDF files that you have to track through the whole way not very pretty good but we translate those into InSpec with our InSpec ESCAP algorithm and so this is just an example of what you can do with that format JSON then you can show people like the profiles of these ones failed, these ones didn't like tips or go to InSpec InSpec.io we're releasing on Monday and I tried to get them to make it for today in another tutorial but they couldn't so on Monday go to InSpec.io because right now it's in the works and what questions


You're not a drop in the ocean, but you are the entire ocean in a drop. I've been asking this question, like, who am I? Where am I from? We have gathered here as global citizens, as citizens of a community of communities. And so global citizenship is not about abandoning where we come from, or it's not about giving up our responsibilities. Global citizenship is about service. It is about coming with humility, coming with respect and a desire to have a positive impact on others. Global citizens go and create value wherever they are. Global citizenship to us is a bridge to planetary citizenship. How can a nation like New Zealand lead finding great value in actually being in a small, agile place that can innovate in this place? Because the opportunity is out there. We have some great challenges in our hands today, and it's really up to us to do something about it.


Welcome back to this nanostructured materials course where we are discussing the synthesis properties, self assembly and applications. We have finished module one in which we had two lectures and in module two we have two lectures earlier. Module two is on synthetic methodologies and in that the first two lectures that we have concluded was based on the sol-gel methodology. The sol-gel methodology we showed how you can make nanostructured materials of various porosities starting from a colloidal sol or a polymeric sol and then convert it into a gel and then into the nanostructured material. It can be made in a film or as a monolith or as a porous interconnected structure. Today is the third lecture in this module two and this lecture and the next lecture will be on another method of making nanostructured materials. This particular methodology is called the micro-emulsion technique and we would be discussing in detail what are micro-emulsions, how we can stabilize them, how we can use them to make different kinds of nanomaterials and also how we can control the size and shape of various nanostructures. So, what are micro-emulsions? Micro-emulsions are thermodynamically stable, optically transparent, isotropic dispersions of aqueous and hydrocarbon liquids. Hydrocarbon means non-aqueous medium and this dispersion of aqueous and hydrocarbon liquid is stabilized by a interfacial film of surfactant molecules. So, what we have introduced here is we have a mixture of an aqueous or a water based solution and a hydrocarbon liquid like an oil which is a non-aqueous medium. Normally the aqueous and the non-aqueous will not mix, but how to make them mix is through a film of surfactant molecules.  These surfactant molecules have this tendency that part of the molecule can be immersed in a water or aqueous system and part of the molecule likes to be in the non-aqueous medium. So, when there is a film or a bilayer or two liquids having an interface like oil and water, then when you add the surfactant molecules they would like to be at the interfacial region. So, these surfactant molecules which are at the interface of the aqueous and the non-aqueous medium can arrange themselves in various forms. So, one of the forms by which the surfactants aggregate is like a sphere and when you form spheres which are mono dispersed, then you can get micro emulsion droplets and these droplets can have either water or oil with diameters of around 100 or less than 100 nanometers. We can control that and that depends on the nature of the surfactant and of course the amount of water and solvent etcetera. So, micro emulsions are mono dispersed spherical droplets of water in oil or oil in water. Of course, we can also have micro emulsions with certain different type of organization of the surfactants. Now micro emulsions and macro emulsions are two different things. So, what is a micro emulsion? A micro emulsion as we just mentioned is a transparent solution and is thermodynamically stable. So, if you see on the left this is a transparent system where you can see through this solution. So, this is a micro emulsion whereas the macro emulsion is opaque and you cannot see through that. And the other properties of a micro emulsion is the size of the droplet that means what is the size of the surfactant aggregates in which the water or oil is present and that size is of the order of 10 to 100 nanometers. And it has high surface area, it has ultra low interfacial tension, IFT is the interfacial tension between the oil and the water phase and this is of the order of 10 to the power minus 2 to 10 to the power minus 3 milli newtons per meter. And you can form water in oil that means very small amount of water droplets surrounded by oil and having at the interface of water and oil surfactants that is called a water in oil micro emulsion. Or you can have oil in water micro emulsion where the content of oil is very less and this is present within these spheres and you can also have by continuous type of micro emulsions. And normally micro emulsion will form at a critical packing parameter of or CPP of 1. On the other hand macro emulsions are kinetically stable, they are not thermodynamically stable, they form large droplets of 1 to 10 micron in size and that is why their solutions are not transparent, they are opaque, they have low surface area of 15 meter square per gram. And normally they will form oil, the oil and water interface will have interfacial tension which is much a higher, some 1000 times or 10,000 times higher than present in micro emulsions. And that is of the order of 1 to 10 milli newtons per meter whereas in micro emulsions it is 10 to the power minus 2 to 10 to the power minus 3 milli newton per meter. And so there is a large difference in the interfacial tension present at the interface in a micro emulsion and a macro emulsion. And that is why macro emulsions because of this large interfacial tension are not thermodynamically stable and they are kinetically stable. Now you can get both water in oil as well as oil in water type of macro emulsions but it is difficult, you cannot get the by continuous type of micro systems which you can get in the micro emulsions. Then the formation of macro emulsion occurs at a critical packing parameter when it is greater than or less than 1, not when it is equal to 1. So the thermodynamics of the formation of micro emulsions can be explained by writing the free energy in the micro energy terms. So the delta g m is the free energy change for the formation of the micro emulsion and that is equal to the formation of free energy change due to the change or increase in total surface area. So when the micro emulsion is forming you are having a change in the surface area and this delta g 1 is a term which relates that the energy to the enhancement in the surface area. Delta g 2 is the free energy change due to the interaction between the droplets. So as these droplets are forming they are interacting and that brings about a free energy change which is given by delta g 2 and delta g 3 is the free energy change due to adsorption of the surfactant at the oil water interface. So these 3 free energy changes are additive and then you have an increase in entropy because you are dispersing the oil as droplets. So the increase in entropy is because you are disturbing the order of water and this enhanced disorder leads to an increase in the entropy and that will bring about a term which is minus t delta s where delta s relates to the increase in entropy due to the formation of the droplets which breaks the order and creates disorder in the water medium. Now if you represent these things graphically so the delta g for the formation of the micro emulsion if you see that this is greater than 0 for emulsions. So emulsions are unstable and hence you see that the delta g m is always positive and it becomes increasingly positive as you come to small distances. Whereas for stable micro emulsions you will have a minimum in the delta g of the formation of micro emulsion and this will be the delta g of the formation distance at which the minimum free energy occurs will give you the size of the micro emulsions. So delta g m star is less than 0 for the formation of the micro emulsion in a particular range of r. So whenever the micro emulsions are forming spontaneously it can only do that when the interfacial tension is very small and that is what we mentioned earlier that the interfacial tension is small of the order of 10 to the power minus 3 milli Newton per meter around that order the micro emulsions form. If the interfacial tension is large then it will not lead to stable micro emulsions. So again to discuss or show you pictorially what is happening you have this two liquids one you can consider the aqueous phase and the other is the non aqueous phase and the two are immiscible like oil and water and you will have an interface at the where the oil and water meet. Now if you shake them giving mechanical energy you can mix them but that is only stable for a small time that is kinetically stable if you give some mechanical energy and that is typically of emulsion it is unstable and it is not transparent. However if you want to make a stable micro emulsion which is transparent you add surfactant and surfactant basically are these kind of molecules which has a polar head group and a non polar hydrocarbon tail. So when you add these kind of molecules in this system this polar head group will go into the aqueous layer and the non polar hydrocarbon tail will go and sit in the oil layer. So it will be lying at the interface but when you increase the concentration of such molecules then you can get some surfactant assemblies like that. So within the solution you will get the small spheres which are basically this kind of surfactant assemblies where these molecules have come together in the form of a sphere and you can see the polar head groups are pointing inwards and the hydrocarbon tails are pointing outwards. So this is a particular spherical aggregate of surfactants where you have a hydrophilic head groups pointing inwards. So this will like water or aqueous medium to be inside because the head groups are hydrophilic because they are polar head groups and the chains outside are hydrophobic. So the oil medium will stay outside.  So this will be transparent but if you look under or use some technique you can find this organization of spheres and the water one of the medium say the B is water will be present inside these spheres and only the oil medium will be outside. So such a spherical aggregate of surfactants in this micro emulsion is typically called a reverse micelle. So a reverse micelle is a micro emulsion where you have the water and oil the water content is much less than the oil content and the water is trapped within the spheres. So then you get reverse micelles if you have the other system suppose these spheres had these tail groups inside and the polar head groups are outside then water would be in the medium outside and oil would be inside. In that case it is called a micelle and when the water and oil is nearly same concentration then you may get a bi-continuous phase. So typically you get a micro emulsion where you have got these surfactant aggregates and one of the liquids is trapped within the sphere and the other liquid stays outside the sphere and it gives you a transparent solution. So this is what is the basic structure of a micelle or a reverse micelle which has got spherical aggregates of surfactants and this particular geometry can help you control the synthesis of nanostructures by controlling the diameter of these nanostructures. So micro emulsion we can now define is a dispersion of water in oil or vice versa that means oil in water which is stabilized by addition of surfactant and co-surfactant. We have introduced the term surfactant before a co-surfactant helps the surfactant reduce the interfacial tension between the water or the aqueous medium and the non aqueous medium. So both surfactant and co-surfactant are basically helping stabilize the immiscible system by lowering the interfacial tension. Co-surfactants normally are some long chain alcohols or amines and we will discuss about them. So to form a micro emulsion you can vary the surfactant, co-surfactant, the water content, the solvent or the oil phase or the non aqueous medium, the temperature all this will affect the size and morphology of the surfactant aggregate and hence any synthesis of nanoparticle will be affected by the variation in the size and morphology. The stability of the micro emulsions is basically due to the decrease in the interfacial tension and the free energy is related or the free energy of formation of the micro emulsion is related to the oil water mixing entropy and the interfacial film curvature energy these are two things which contribute to the free energy and the interfacial curvature energy is related to the surfactant rigidity and film flexibility. So the interface curls when droplets are formed and hence there is an increase in the interfacial area and that is related to the free energy term due to surface area. So you can look at the picture that you have this kind of droplet where the surfactant molecule tends to adsorb and in this case if this is the head group which is polar then it will the hydrophobic tail will be going into the oil droplet or the non aqueous medium and the polar head groups will be in the aqueous medium or wherever there is water. So this is the normal structure of a reverse micelle or a water or sorry this is the structure of a micelle where oil is inside and water is outside. So this is also called an oil in water micro emulsion. Now so in general micelle formation is an entropy driven process as mentioned earlier it creates whenever you form these micelles or this order of aggregate of surfactant molecules there is a disorder in the structure of the water due to the micelle formation and the driving force is that the alkyl chains want to be away from the aqueous solution. So it tries to eliminate the contact between the alkyl chains and water and that leads to the formation of these micelles so that is the driving force. So this we have discussed little bit earlier this is a surfactant molecule which has a polar head group and it has a non polar hydrocarbon tail and we can control the size of the polar head group we can change the charge on the polar head group you can have many types of charges positive negative neutral you can have many kinds of these hydrocarbon tails very long tails we can have two tails and we can have three tails. So you can design many kinds of surfactant molecules now what is the effect on of these surfactant molecules it affects the growth of the particle since it provides an initiation site for the inter micellar exchange it stabilizes through the self assembly of these surfactant molecules and the size and charge of these polar head groups and tails affect the packing and growth of the nanoparticles which will be synthesized within these spheres which may be micelles or reverse micelles. Now there are varieties of surfactants for example you can have anionic surfactants for example is SDS in short which is a sodium dodecyl sulfate or you can have with the molecular formula given here you can have something which is called sodium base 2 ethylhexyl sulfosuccinate and that formula is given here and that its commercial name is AOT it is a very common surfactant and these as you see will have a negative head group if you dissociate this sodium ion there will be a negative charge on the head group of this molecule. So both these are anionic surfactants because they will have a negative head group when this molecule is dissolved in water. So AOT and SDS are both anionic surfactants you can have zwitterionic surfactants like SB 316 which is hexadecyl sulfobetane this is the formula and you can have cationic surfactants like CTAB this is the most popular one of the most popular cationic surfactants where you have this 16 carbon chain. So it is C-tile trimethyl ammonium bromide so you can see that is a C-tile due to the 16 carbon chain and you have a trimethyl group and you have a bromide. So once you dissolve this in aqueous medium the bromide ion will ionize and remaining one positive charge will be on this nitrogen. So you will have a cationic surfactant so CTAB is a cationic surfactant similarly you can have DDAB where you have a 12 carbon chain again a bromide so there will be a positive ion on the nitrogen when this molecule dissociates in water. So you can have anionic zwitterionic that means both positive and negative charges in this system positive on the nitrogen and negative on this side and you can have non-ionic surfactants but with a polar head group. So for example you have tergitol NP9 this is the commercial name very commonly used and then tritone X100 this is another commercial name with this kind of molecule and in this cases as you see there is a ether linkage here and that gives the polarity although there is no charge on the head group but it is a polar molecule and these are non-ionic surfactants. So this is an example of anionic surfactants and you can see these are the negative charges on the head group and this is the hydrocarbon chain you can have cationic surfactants where you have this positive charge on the nitrogen and you have a hydrophobic tail so this is the hydrophilic or polar head group and is the hydrophobic chain you can have non-ionic surfactants like this molecule where you have a head group which is non-ionic but it has some affinity for water and this is the hydrocarbon chain which has affinity for oil or non-aquas medium. You can also have surfactants like this which is an alkyl glucoside and a glucose ester as well so they make together an alkyl glucoside and a glucose ester make this alkyl polyglycoside which is acting like a surfactant because it has a hydrocarbon or a non-aquas loving tail and you have a polar head group though uncharged it has some polarity so there is a variety of surfactants which is available. You can also have bio surfactants that means surfactants which are known in nature and these are some complex molecules this is called a sophorolipid this is a glycolipid and there are several such molecules which are available in nature so surfactants like this are useful if you want to do anything in pharmaceutical industry or the food industry where biodegradable molecules are more important and so these kinds of surfactants can be used for applications in those kind of industries. Now you can have phospholipids like this which are known very very well known where you have this hydrophobic tail and then you have a polar head group which is acting here these are neutral surfactants but and also they are bio surfactants so neutral bio surfactants you can have interesting surfactants which you can design for example this is a surfactant molecule which does not behave like a surfactant as such but when you have past carbon dioxide through the solution then it becomes ionic and then it behaves like a surfactant that means it can then aggregate if you put it in sufficient quantity in a solution containing water and oil then it can give rise to spherical aggregates or different shapes of aggregates like micelles or reverse micelles depending on the concentration of carbon dioxide so the carbon dioxide triggers this molecule which is not a surfactant here but in the presence of carbon dioxide becomes a surfactant so such surfactants are called switchable surfactants you can have redox active surfactant for example there is a surfactant which is like a monomer that means it is not organized in any shape they are all loose the molecules are separate but when it takes up an electron so when if you give some electrons from an electrode it picks up electrons if it does that then it starts aggregating so it becomes like an empty micelle so the hydrocarbon chains are inside and the polar head groups are outside so inside of course there is nothing right now so this is an empty micelle but if there is some oil suppose you at the next stage you introduce some oil a non aqueous solvent then these micelles can take up those oil and then they will become filled micelles and then if you remove an electron this aggregate structure will be destroyed and this will open up and the solvent will go and stick there whatever is there and they will then again be monomers so from monomers to spherical geometry or the surfactant aggregates in the presence of electron takes up some oil and then gives out an electron to break up and leaves the oil and again you can cycle these monomers so this monomer to surfactant aggregate through either reduction and then opening up of the micelle through oxidation this kind of redox active surfactants are also known so this is an example where you have used electrochemical assembly and disassembly of surfactants you can do the similar things in molecules which contain say ferrocene so ferrocene is this iron with two cyclopentadienyl groups and the other side is a chain with some trialkyl amine and this is a hydrophobic chain now if you take out an electron then you can change this ferrocene to ferrocenium iron so there is a positive charge because one electron has been removed and if you add an electron to this then you get back this ferrocene derivative so you can go back and forth by removing electrons or adding electrons and these are again redox active amphiphilic molecules, amphiphilic molecule, amphiphiles are basically again surfactants anything amphiphile means that it has a possibility of adhering to hydrophilic as well as hydrophobic moieties so any surfactant is an amphiphile. Now there are certain terms which are used in micro emulsions and surfactants and reverse micelles etc one is what is called the W naught parameter which is related to the ratio of concentration of water is to surfactant so how much water is there with respect to surfactant so for example you can have aggregates containing small amount of water that is W naught equal to 15 and they tend to form reverse micelles and whenever you have micro emulsion with W naught greater than 15 you can get lot of water basically what you are saying is as you are increasing W naught you are adding more water in the system so water is to surfactant ratio is given by W naught. Now you have another term called the CMC which is called the critical micellar concentration and this is the minimum concentration of the surfactant at which the aggregation of surfactants to a micellar structure will take place and that is called the CMC or critical micellar concentration for different systems the CMC is different so if you choose a micelle if you choose a surfactant A with water and say a solvent like hexane you will have some critical micellar concentration CMC now if you change the surfactant A to surfactant B keeping water and the solvent same you will have a different CMC so the CMC depends on the kind of surfactant you are using and the kind of solvent you are using etc. At the CMC when the surfactant aggregation takes place there is a sudden change in the properties of the micro emulsion or the system. Now these changes in properties can be studied easily if you study the viscosity or the light scattering or conductance or surface tension many of these properties will change sharply at the critical micellar concentration so it is easy to determine what is the concentration of the surfactant at which the micelle forms now there is another term which is used which is called the craft temperature this is the temperature at which the solubility equals the CMC. And that temperature is called the craft temperature so these are certain terms which are used regularly in the study of micro emulsions and surfactants and nanoparticle synthesis of surfactant using surfactants and micro emulsions and one has to understand these terms because you have to change these parameters optimally to get the right kind of surfactant aggregates which will help you control ultimately the size and shape of the nanoparticles which you want to synthesize within these surfactant aggregates. So here we show you if you have a surfactant like CTAB which has this surfactant which is a cationic surfactant and has a polar head group and polar head group at this tri alkylamine side and there is a long hydrocarbon 16 carbon chain which is the hydrophobic chain. Now there are you can find out what is the typical hydrocarbon tail length and it will have a typical head group area. So this head group area and the tail length are very important in understanding what kind of aggregate these surfactants will make. So as you change the surfactant from CTAB to SDS which is a anionic surfactant to Triton X100 which is a neutral surfactant. So you go from cationic to anionic and to non-ionic surfactants. If you vary the dimensions you see here the length of the tail is 20.5 angstrom whereas in this case with this 12 carbon chain the length is smaller. Obviously this is 12 carbons and this is 16 carbon chain. So the length will be smaller in this case it is 16.7 and in this Triton X100 it is 11 angstrom. So you can vary the length similarly you can vary the area of this head group. So here as you see the head group area is very small in the non-ionic surfactant whereas in these cases the head group area in the cationic surfactant CTAB is much larger. Now these will affect the type of geometry and the critical micellar concentration at which the surfactant aggregates will form. So if you start what happens when you start adding surfactants to say water. You have water and you are adding a surfactant molecule initially the surfactant stays at the interface. So you have water and say oil or some other medium which does not dissolve in the which is immiscible in water. So then the surfactant molecules try to remain at the interface with the polar head groups on the side of the hydrophilic liquid which is water. And the tails point towards the liquid which is hydrophobic. After a certain concentration that means after you have added 4, 10, 20 certain number of molecules of surfactants this surfactants tend to aggregate. And when they tend to aggregate they take the water within their aggregate because the head groups want to be immersed in the hydrophilic part of the system and outside you have the oil remaining. So this is typically how as you vary the concentration the surfactant molecules agglomerate in a particular manner and they solubilize the water inside and this is a typical formation of a reverse micellar. So what is the W naught value? What is the CMC? Those things are important to design the typical surfactant aggregates that you want in a particular system. Now you can get not only this kind of spheres spherical aggregates of surfactant like this is the reverse micell or water in oil because water will be inside and oil will be outside because the polar head groups are inside. This is the micellar where you have the hydrocarbon or hydrophobic tails are inside and the polar head groups are outside. So this is a micellar which will trap the oil medium and this is a reverse micellar which will trap the aqueous medium. These are spherical aggregates of surfactants but you can get also other type of structures like this is a lamellar phase where you have this polar head groups on one plane like this and the tails are inside and there is another layer of polar molecules whose tails are inside. So there is a tail tail these are hydrophobic tails which like each other and they arrange themselves in this lamellar phases. You can have cylindrical micelles where you have this hydrophobic tails pointing inside and on the surface of the cylinder you have all the hydrophilic or polar molecules on the outside. Similarly you can have vesicles like these which is like one layer inside another layer and the vesicles are known in our living systems also in living bodies we have vesicles and these are typical bicontinuous structures which we said can also be present in micro emulsions. So you can have different types of structures of these surfactant aggregates which are controlled by the concentration of surfactant, oil, water and the type of these individual chemical entities. These are some other shapes which are different. Here you can see a cone shaped surfactant which results in a normal micelle and if you have this kind of a surfactant where you see you have a polar head group and you have 3 or 4 different tails and that forms what is called a cork shaped surfactant which is again it is a reverse micelle. Here it is of course a micelle and typically if you have 2 or 3 hydrophobic tails then invariably they lead to reverse micellar organization where you can have aqueous medium. In the micelles you can have the non-aqueous medium inside. You can have more complicated structures which are interconnected cylinders like this or planar lamellar structures or onion like structures that means there is one reverse micelle here and then there is another organization of surfactant molecules such that you have 2 polar head groups interacting with each other here. So, these are called onion like structures. So, variety of surfactant aggregates are possible which self assemble themselves under certain conditions in colloidal solutions. Now, there are certain parameters which govern which depend on the length of the hydrophobic chain and the area of the head group etcetera and there is a parameter which is called the surfactant packing parameter n s which is related to the volume of the surfactant molecule divided by the area of the polar head group which is multiplied by the length of the hydrophobic tail and typically if you do proper calculations of these numbers you will find that most of the time you will get spherical micelles if this n s value or the surfactant packing parameter is 1 by 3 or you will get cylindrical micelles when it is 1 by 2, you will get lamellar micelles when it is 1 and you may get reverse micelles when it is greater than 1. So, in this equation all these parameters of length of the hydrophobic tail, the area of the polar head group, the volume of the surfactant molecule all come into the picture which ultimately it can be put together as one parameter and which gives you a guide to what kind of shape you will finally, end up with when you use different types of surfactant molecules which have different lengths and different area of the head group. So, typically when you want to synthesize nanostructured materials using these micro emulsions you can start with thinking that you want to make spherical particles which is simplest and so you start with reverse micelles as nanoreactors why we call them as nanoreactors because this moiety where there is an aqueous medium here and you will be synthesizing the particles within this. So, this whole thing is like a reactor the only thing is this diameter is in nano dimensions it may be 5 nanometers, 10 nanometers and so these kind of surfactant aggregates with aqueous solution inside can be treated as nanoreactors. So, this is the aqueous core where you will you can do your reactions to give rise to inorganic particles of course, if you want to use nanoreactors to synthesize organic particles then you will have to use micelles and not reverse micelles because in a reverse micelle you can only do synthesis with metal ions which are which get into the aqueous medium and for organic systems this part has to be a non aqueous medium and so you have to use a micelle where the hydrophobic tails should be pointing inwards here the hydrophobic tails are pointing outwards and the polar head groups are pointing inside and so inorganic solids or nanoparticles can be formed within this reverse micelle core. Now, using this you can get mono dispersed water droplets which leads to small particles because it inhibits the growth and aggregation of particles and it is easy to control the size and shape of the particle because you can control the size and shape of the aqueous core. Now, when you have this kind of system of micro emulsion the understanding of the phase diagram is very important because you have water you have a non aqueous medium and you have a surfactant now this is called a ternary phase diagram and within this ternary phase diagram some compositions will lead to say micro emulsions some composition will lead to micelle type of micro emulsions some which are called oil in water micro emulsion or in some other area typically we will have got less water. So, you are away from water these regions you will get water in oil micro emulsion of course, you can also get gels or in certain regions of the phase diagram. So, what this phase diagram tells you what should be the composition of your micro emulsion system in order to get reverse micelles or micelles and to understand this phase diagram is very important because you have to choose your system properly. So, if you want to synthesize a material in a particular surfactant oil medium you have to know its phase diagram because you want to know what is the composition of the oil water surfactant which you need to choose and. So, these are typical some examples of water isoctane is the non aqueous medium C-tab is the surfactant there are different types of phase diagrams you can generate and some phase diagrams are known in the literature some you have to find out whenever you want to work. So, this kind of a ternary phase diagram is very important to know. However, if you add a co surfactant then you have not only water surfactant and oil you also have a fourth component which is a co surfactant. So, you will have to draw or understand a quaternary phase diagram which is still more complex. So, you have to use phase diagrams and to tune the phase behavior you can control the temperature the co surfactant and the salt and then you can understand what is called the water emulsification phase behavior. So, you want to make discrete water droplets in oil and there is one term which is called the water emulsification phase boundary you can have these water droplets only when you are at within the boundary otherwise this will fail and you will get separate droplets of oil and water. So, W E F B if you know you can do the controlled synthesis of nanoparticles. So, basically you need to know the phase diagram of the system which will tell you where is this water emulsification failure boundary. Now, the water emulsification failure boundary W E F B is also dependent on salt concentration and ionic strength. So, if you keep the same surfactant oil and water, but if you change salt concentration or ionic strength then you see you can move to different or lower amount of iso octane or because this is iso butanol this is a being used as a co surfactant. So, if you add more sodium chloride which is a salt if you add more salt you move this side which means you move to lower concentration of butanol. So, butanol is being used in this system as a co surfactant. So, with less co surfactant you can stabilize the micro emulsion system by adding salt. The salt actually gives ions and these ions compete with the head groups for hydration which lowers the hydrophilicity of the surfactant and the repulsive interactions of the head groups decrease and that means that your interfacial tension is lower and you need less amount of co surfactant to achieve the condition of interfacial tension to go to zero. Now, is ionic concentration the only parameter determining the water emulsion failure boundary no ionic concentration is one parameter, but in the if you change the ions both say compare sodium ion and H plus ion both have one positive charge. However, H plus ion gets more hydrated than Na plus ion. So, the effect of H plus ion is more than Na plus and you can see the shift is more towards less butanol requirement for stabilization of the micelles or reverse micelles compared to sodium ion and this is basically related to the hydration ability of H plus ion which has more hydration ability compared to sodium ions. So, you can change this behavior of the WEFB or the water emulsion emulsification failure boundary to lower values of one butanol by adding salt. Now, typically when you want to synthesize nano materials what you do is we make micro emulsions of say a metal A. So, if you want to make a compound AB nanoparticles of a compound AB in one of the micro emulsions that means you take A ions and in another micro emulsion you take B ions. So, you first create micro emulsions by having your aqua solution which contains the A ions your solvent which is a non aqua medium and the surfactant and then in this you have the B ions in aqua medium and then solvent and the surfactant. So, you get transparent micro emulsion 2 and transparent micro emulsion 1 and you mix these two micro emulsions and then they collide and coalesce and during this collision and coalescence there is exchange of A ions from here to B ions from here and then you get the compound AB and the size of AB is controlled by the size of these droplets. However, the size of this AB is not exactly equal to the size of these droplets but will be larger than the original size of these droplets because two or more droplets are interacting to give these particles. So, this is how you can prepare nanoparticles by the reverse micellar route using surfactants or micro emulsions. Now, the kinetics of these inter micellar exchange. So, this is the step where you are having the inter micellar exchange and the kinetics of the inter micellar exchange rate compared to the overall or bulk reaction rate is very important in determining the mechanism. Now, if the exchange rate is very high compared to the bulk reaction rate then the exchange does not have any particular role to play on the particle formation. However, if the exchange rate the inter micellar exchange rate if it is slow then it becomes the rate determining step in particle formation and then the mechanism depends on the inter micellar exchange. Where first we there is an encounter pair that is two micellar units come together to form a pair and then a fused dimer. So, in this inter micellar exchange when it this is the rate determining step this is slow compared to the bulk reaction rate then a mechanism has been proposed in 1987 where it is said that the two interacting micelles come together to form an encounter pair and then they fused to form the fused dimer and this is the slowest step. So, there is a fast pre equilibrium step which is the association of the two droplets to give an encounter pair and then a slowest step for the fused dimer to form and the rate constant for this exchange is given by these equations. During inter micellar exchange when the fused dimer is formed the exchange rate is dependent a lot on the curvature here. If the curvature is very high then this exchange is more difficult. So, the inter droplet exchange of the particles is inhibited by the inversion of the film curvature in the fused dimer and this how much this will curve inside depends on the film flexibility and that will affect the micellar exchange. So, after the particle nucleates that is the nucleation stage then there is a growth of the nanoparticles. Now the growth of the nanoparticles typically follows what is called the Oswald ripening rule. It is a thermodynamically driven spontaneous process where large particles grow which are energetically favored at the expense of small particles. So, some small particles will form and then they will dissolve and some large particles will form and this will continue till the larger particles become larger and larger and the distribution that is the particle size distribution will become much narrower. That means you will have a large number of particles of one particular size and then you will have very few numbers of sizes which are much smaller. Now this is called the Oswald ripening process. This is the thermodynamically driven process and during Oswald ripening what happens initially you have many of these particles which are forming many nuclei which form and then the smaller particles dissolve becoming larger particles. The inner core particles dissolve first because the surface energy is higher at the inner cores. So, the higher curvature gives higher surface energy and easy to be dissolved. So, the inner cores dissolve first and the outer cores are present and this is a model and this is what is seen in experiments. So, you see the inner cores it is dark here and then it becomes lighter and so this is a process by which you are getting this Oswald ripening to give rise to these particles and so thermodynamically this is the process the Oswald ripening process how the after nucleation the particle will grow. So, we will stop our lecture here and we will continue the second lecture on micro emulsions in the next lecture. We will continue how the particles grow using Oswald ripening and we will consider other aspects of synthesis of nano structures by micro emulsions. Thank you very much.


Today fellow investors, I'm here in the beautiful town of Split in Croatia, still on holidays and not because it's not beautiful but it came to my mind that I can discuss the worst possible investments you can make. And the one of the worst investments you can make is not a boat but let's say when you confuse luxury and an investment. I see a lot of people investing in a boat, in a second home, in a car and things like that where they think that it is an investment but when you calculate the return on investment it ends up negative and it's much better that they invest in some normal piece of real estate and then they can pay with that one month in a five-star hotel instead of sitting in a small second home apartment somewhere I don't know so that's one. The second worst kind of investment you can make is something like this this is supposed to be hotel that went bankrupt and that's a pension fund investment like so the payback period of a hotel like this is 15-20 years if everything goes well usually it goes wrong and then the return on investment is negative or 1-2 percent over 20 years so the story might be very very tempting you see this city you see the thousands of tourists the cruisers the everything and then you say oh a hotel here would be a very smart idea but then it ends up badly so those kind of investments pension fund like investments are very very bad and the third type of investments you can go wrong with are advertised investments those that you see on the banners when you watch this video wherever something is advertised it means that you are paying for the advertisement it means that it cannot find investments by itself so I would definitely stay clear from such investments looking forward to your comments please share other worst kind of investments you can think of and let's hope that our investments really lead us to a life of luxury I'll see you in the next video