Saran Wrap, X'Pert Pro and More Wrinkling

For the last couple of days, Jiangshui, Sabra, Dave and I had been discussing how we could bring these experiences with wrinkling into the classroom. Today we tried what we thought would be a good idea. Saran Wrap! Its a film, sort of thin, could float on water. I am including a picture (for educational purposes) in case anyone has not seen this wondrous product.Sabra brought some from home. We got a large glass container to hold the water. Jiangshui cut out a piece, kind of circular, and placed on top of the water. The saran wrap floated. That worked, next, we used a pipette to place a drop of water on the saran wrap. Success? Nope, failure. No wrinkles. Added more water, still no wrinkles. Added more ....... No success. We decided that the saran wrap is too think. Tried parafilm. Did not work. Tried glue between slides. Just came apart, no film developed. It seems that the film must be a nanostructure. Sabra thought of the film that develops on top of pudding or scaled milk. We will keep thinking about it. Remember though, just because they were failures was not bad, it helped us figure out possibly why.

For the rest of the day, we worked on floating films for wrinkling and placed a slide for x-ray reflectivity.
We made the films by spin coating.

The floating went well. Took lots of pictures since we did three slides a piece. None of us had any problems with the films today and we did them a lot faster. All the practice has helped us get better at this procedure

We went back to check the results from the x-ray reflectivity analysis. The film was ~100 nm. This is a bit higher than the other films and higher than Jiangshui's. When we compare these readings to what we have done before and to the number of wrinkles, we seem to be getting a trend of Dave's films have a lower thickness, Sabra's have a higher thickness, and mine fall somewhere in between. This could account for the difference in the number of wrinkles. Since we have taken turns on whose slide get analyzed, we have not kept track if we are being consistent on our own slides. We have decided for tomorrow to show up early so we can do at least two slides in a row for each of us to see if we are each dealing with different thicknesses. This difference could be due to our own way of making the film. ** Scientific Method at Work **

More Practice and Filmetrics Interferometer

Today, we were going to practice more on floating of the PS films and checking the thickness of the films. We are going to learn how to use the Filmetrics Interferometer.
Everyone made two films for wrinkling analysis at Hasbrouck. An additional slide was made for X-ray reflectivity. We set up the X'Pert Pro for analysis for the thickness of the film. We made a quick video on placing the slide on the stage. As you can see, it takes a couple of tries sometimes for it to close correctly and then it must be raised or lowered, using a screwdriver, to get the proper count rate to start the analysis.

We left it running and went to Hasbrouck to perform the wrinkling.

We went through the usual procedure. Cut out film, float film, add 2 microliters to the center, take picture of whole film and zoom it and take picture of wrinkles. Go through all the increments and take pictures at each one. Each of us did our films, I messed up on one. When moving the film towards the middle to take the picture, I touch the top of the film instead of the side and it created wrinkles all over the film so I could not continuing using it. This is why we, or I, need practice on this procedure. Save the pictures of analysis.

In the afternoon, Ling Yang showed us how to use the Filmetrics Interferometer. This instrument uses reflection of light directed at the film so the light must bounce back. This would not happen if we used a glass slide so we used a piece of silicion sheet instead as our substrate. We broke off a piece of silicon and spin coated, at a slower speed since the interferometer needs a thicker film to analyze.

Once spin coated, we took it to the room with the interferometer but that one was not working so Ling Yang took us to her interferometer set up. She demonstrated how to calibrate the Filmetrics interferometer and how to focus the light. This is required to acquire accurate readings.


The thickness range for the Filmetrics is between 30 nm to 1mL which would be adequate for our thickness readings on our films. But, there is always a but, the X'Pert Pro gives much more accurate readings for thickness. And since were are comparing wrinkles and thickness, we want the most accurate readings possible.

Thesis Defense, Image-J/Excel and Group Meeting

We started the day by going to a thesis defense. Richard Woudenberg presented Anhydrous Proton Conducting Materials for Use in High Temperature Polymer Electrolyte Membrane Fuel Cells. As I understood it, he works for the Marken corporation and was given time and support to get his PhD. He talked about developing materials that did not require water, anhydrous, to function. He mentioned work on polymer electrolyte membrane fuel cells. Some of the other stuff he mentioned was a bit over my head. But I need to say, it was very interesting to see someone going through this process and seeing what they had to do.

After that, we went to the Russell Group computer room and started analyzing the pictures from the wrinkling. We opened up the pictures using Image-J to get the pixel areas of the whole film, of the water drop, of the wrinkles, of the water drop again, the zoomed in picture, and the number of wrinkles. Once we had the areas, we used Origin or Excel to analyze the data to determine the diameter of the water droplets and the length of the wrinkles.

After lunch, we attended the group meeting for the Russell Group. These are the students, working on their PhD's, and post-docs working with Dr. Russell.

Other people that are not in this picture: Ji Xu - Sivakumar Nagarajan - Narupol Intasanta

During the meeting, which are usually held weekly, some of the individuals were called on to give a talk on an assigned published paper. The individual must describe what the experiment or idea is and give their opinion on it. Dr. Russell asks specific questions to either check what was on the paper or to force the individual to think what can be done with this information. Other individuals gave a presentation on the progress of their current research. Another experience into what is involved in attaining a PhD. Quite Fascinating.

Wrinkling, X-Rays and Dr. Russell

Started off the day setting up threes slides. One was set up for X-ray reflectivity. We set up the X'Pert Pro. Since it takes 1.5 hours, we left it running and went to Hasbrouck to do the wrinkling. We are getting more proficient at the wrinkling procedure. We are becoming faster at adding the 0.2 microliter incremental amounts and at taking the pictures of the film and of the wrinkles. Each one of us did two films with the given amounts of water and the pictures at each point and transferred the pictures to the computer. We will analyze the pictures later.

Met with Dr. Russell today. We discussed what we have done over the last two weeks. We mentioned all the instruments we have been trained on, the spin coating procedure and the wrinkling procedure. He talked about how the x-ray reflectivity worked and related it to the colors seen on the surface of the bubble, same as an oil slick on water. They both show colors based on constructive interference, destructive interference and index of refraction which can be used to determine the thickness of the "film."

We went to look at the data from the X'Pert. The data looked good once it was set to a logarithmic scale. It showed the peaks and the troughs that we needed in order to calculate the thickness of our film.

We got the necessary data from the troughs and calculated, using Excel, the thickness of the film. It came out to 98.133 nm, which is a bit thicker than we should have gotten.

We spin coated two more slides and took them to Hasbrouck to do the wrinkling on them. We have lots of pictures so we will need to start analyzing them soon. For now, we want to make sure we can do the procedures and that we do them well. Practice, Practice, Practice. :-)

SEM (very cool), Lecture, Current Research and Wrinkling

The day started off with Dian, one of the PhD candidates, showed us how to use the Scanning Electron Microscope (SEM). In the morning, we went to one of the microscopy rooms. This room held the Transmission Electron Microscope (TEM) and the Scanning Electron Microscope (SEM). Dian first showed us around the room. She then started setting up the sample to be coated with gold. Samples must be coated with either gold or platinum so that they conduct electrons and so the SEM doesn't destroy it during the analysis. The sample is set up on a metal base and carbon tape. This way the sample is set up to conduct during its use on the SEM.

Once coated, the sample is ready to be placed in the SEM (pictures of the sputter coater are in Sabra's pictures link Dian placed the sample in the SEM and we were able to see the sample and zoom in on it to see the nanotubes.

Dian showed us how to use the SEM and then each one of us had a chance to use it on a new part of the sample. Dian is trying to determine the thickness of the nanotubes and the roughness the exterior.


After working with the SEM, we went to another lecture by Dr. T. Hashimoto. In this lecture, he talked about how carbon black affects polymerization. The research was using the same scattering techniques that he talked about yesterday. And that is about all I really understood. :-) Just a bit over my head on these discussions. After that, it was time for the Friday Talks/Lunch. The talks were given by two PhD candidates and it was about their current research.

Chris talked about his work in photovoltaic cells (solar cells) but using organic substances. Since its organic, it would make the cells much less expensive which is one of the problems with solar cells. Since they are nanostructures, it may make them more efficient which is another problem for solar cells. Andrew talked his attempts of getting polymers to self heal. Just like when we cut ourselves, our skin repairs itself. The group Andrew is in is trying to figure a set up where polymers can repair themselves. There are quite a few ideas on how polymers could do this.

In the afternoon, we set up more slides. One for X-ray analysis and the others for wrinkling practice. We need quite a bit of practice doing this; it is very precise work. Practice makes perfect.

Analyzing with Image-J & Origin, Lecture and X-Rays

We started off the day by analyzing the pictures of the wrinkles. Image-J is used to determine pixel areas of the whole film, water droplet, wrinkle film and water droplet at different magnifications. Origin takes this data and sets up a ratio between the areas and then by comparing it to the known diameter of the film is able to calculate the length of the wrinkles. The wrinkle length is one of the parameters we wish to calculate. The other parameter is the number of wrinkles. We still use Image-J, but just to zoom in, and we manually have to count the wrinkles. Like I mentioned, Image-J is on the Internet for free but not Origin so I converted the formulas from Origin to Excel. This way I can do the analysis at the dorms, if I need to.
Around lunch time, Dr. T. Hashimoto from the Japan Atomic Energy Agency in the Advanced Science Research Center gave a quick lecture on ..... (look at the pictures below)

The first picture is for the title of the lecture and the second picture shows some of the methods used for the analysis of the samples. One of the main things he was talking about was how the cellulose nanostructures look very similar to the smoke coming out of volcanoes. So it seems that when the cellulose self assembles it follows some physical behavior that may be inherent in all substances. The rest of the lecture was interesting especially types of scattering used for analysis.
The rest of the afternoon we continued analyzing the wrinkles with Image-J and Origin and we set up a sample for X-ray reflectivity. The film had a thickness of 93.895 nm.

Spin Coating and Wrinkles

We will work on setting up the slides by spin coating and then going to the Hasbrouck building, since that is where the microscope is set up, to take pictures of the film and the wrinkles.
Placed three large petri dishes in the hood, they will hold the finished slides. Placed several weighing papers inside on the bottom to keep the slides from getting contaminated. Each petri dish will hold the three slides that each one of us will make. I made my slides by the usual procedure: clean surface of spin coater, place slide on spin coater, set speed to 1200 RPM, clean slide with acetone, spin to remove acetone, place solution on slide, spin to coat slide, remove and place in petri dish. Once I was done will all three, I covered the petri dish, this is to prevent contamination here and on our way to Hasbrouck. Sabra and David prepared their slides.
We walked over to the Habrouck building since that is where the instruments are set up to take the pictures of the wrinkles.

We then set up the slide so we could score the size of the film we wish to float onto the water.

We then floated the film onto the water and started the wrinkling by adding tiny amounts of water,2 mL at a time and taking pictures.


During each addition of water, we took picture of the overall film and a picture zoomed in on the drop and the wrinkles it created. The pictures were then analyzed using the Image-J program, for areas, and then the Origin program, for numerical analysis.

For more pictures of the process, check the pictures link on the upper right hand of blog.

X-Rays and Another Method of Determining Film Thickness

Still about a week behind. Sorry. Though, I have been working :-) I had to set up my new website for the school I am moving to. And learned how to use Picasa for the pictures I am using on the blogger. Also found the site for the software we use to analyze the wrinkles, its free. Anyways, let me continue on the blog.

Today, we will use the X'Pert to detemine the thinkness of more film samples that we set up. We followed the same procedures as before: set up the spin coater, prepared the slide by cleaning with acetone, set up the correct speed for the spin coater, applied solution and started spin coater, if the film looks good, take to X'Pert room. Jiangshui allowed us to try it on our own, with him watching us. I really feel like a scientist at these times. We each tried it. We started up the X'Pert, put in the required settings for thickness analysis, set up the required componts, started X'Pert to detemine the "blank" and correct peak settings, placed slide in the X'Pert, set to required count rate and began analysis. Will take 1.5 hours so we went to explore another method of determing film thickness.

The other method requires a Profilometer and a cut on the film. This device actually places a very small needle, the stylus, on the surface of the film. The needle moves across the surface and then drops into the cut and then comes back up. By analyzing the readings from the normal surface height and the height of the cut, the computer can determine the thickness of the film.



This is a great device for deteming thickness since it is very easy to use. The only problem is that the film must be at least 1 micron or micrometer ( mm) and our films are ~90 nm which is ten times smaller than what can be used by the Profilometer. Because of this limitation we can't use it on the films we are working on so we made an extra one but it was made by dissolving a styrofoam cup in toluene. We let it dissolve for about an hour while we were doing the x-ray reflctivity and then did the spin coating with it. After setting up the profilometer and adjusting the stylus (see picture above). We started the device and collected the data. The data must be standardized and then the comparison is done. The film was about 1.36 microns ( mm) .

Even though we will not be using the profilometer, it was an experience to work with it. Remember it is called the Research Experience for Teachers so we are learning and experiencing all we can in the lab. Later on we will get to see how a scanning electron microscope works and other instruments along the way. We went back to the X'Pert and looked at our data on the computer and calculated the thickness to be 93.478 nm.

Woo hoo!! Got to work with the X'Pert Pro for X-Ray reflectivity

On Monday, we worked with a very interesting instrument. Its the X'Pert Pro and it used x-rays to measure the thickness of the films. We read a few articles online to familiarize ourselves with the process. One of the articles gives a very good explanation on how it works. Lots of math but the software in the X'Pert Pro does it for you. Here is a picture or check out more pictures by clicking the link on top right section of the Blog.



We can't use a simple device like a ruler or a Vernier caliper to measure the thickness of the film. Those can only measure in the centimeter or millimeter scale and they could damage the film. Since the film is in the nanometer range, billionth of a meter, we need something much more precise. X-ray reflectivity works on the concept of the reflection of the x-rays by the film and by the glass slide the film is on. By comparing the reflections from both materials, we are able to calculate the thickness of the films we are working on, which are between 88 to 95 nm thick.
We first had to set up the X'Pert to analyze using x-ray reflectivity. This is because it can be used for several other x-ray analysis. Once the correct components have been set up, the instrument must be calibrated to analyze the slide with the film. Jiangshui went through quite a few instructions since we will be doing the analysis ourselves later. I won't go through the steps but just know the instrument is set to analyze the film by x-ray reflectivity, the angles must be set for precise measurements, and it must be set to a "blank" before starting the analysis. Once set, the slide is placed in the X'Pert Pro and set up for the thickness of the slide and it runs for 1.5 hours, going through different angles of reflection. When it is done, the graph is analyzed for certain crests and troughs. This is what is used to give us the final thickness of the film. The film, at least today, came out to 86 nm.

Filtering, Spin Coating and Current Research

The day started with the filtering of the PS solution that we made yesterday. The reason for the filter is that the solution may contain impurities and they can easily be removed by filtration.
We used a syringe, without a needle, to take up the solution and then passed it through the filter. The filter is specially designed to fit the syringe and it goes into another vial to hold the solution. The filter is really small. Here you can see it compared to a dime.

We had each made two solutions and we filtered each one. We then closed them and used parafilm to keep everything in.
After filtering the solutions, we set up the instruments to do the spin coating of the solution onto a microscope glass slide.

During lunch, some post-docs talked about the current research they are doing here. The first one was about antimicrobial polymer films that would be very useful in hospitals to prevent infections, like MRSA. They would be great for contact lenses to help prevent infections to the eyes. The second one was about attaching virus nanoparticles to silica and gold substrates. This would be used to check how the particles are aligned on the substrate since it is easier to see this using the virus nanoparticles.

Making the Solutions

On Thursday, we started making the solutions that will be used for our research of Polystyrene (PS) thin film wrinkling.

The day started off with Jiangshui giving us some notes on how to make the PS solutions and to make sure that it was a certain concentration. More notes .....

We went to the lab and started making out solutions. The PS was massed and then dissolved in a certain amount of toluene to produce a solution of ~ 1.4%. Solution must be left to completely dissolve over a couple of hours.

One more article to ready. Soft Matter with Hard Skin

First Days of Starting Research

Blog is a little late since Windows Vista is messed up. It won't pick up my USB drive or the camera.

The first two days were just background information and several papers we needed to read. Dr. Menon gave us a quick review of surface tension and elasticity.

I had been planning on rewriting my notes but then I noticed a scanner in the computer room so I did that instead.

We had the following journals/articles to read

Mechanics of Scars

Geometry and Physics of Wrinkling

Surface Tension

Hooke's Law

Poisson's Ratio