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 **