Experimental pictures

Emulsion droplets, sandwiched between two glass plates which deform them into quasi-two-dimensional disks. Picture from Ken Desmond. Colorized version of the raw image.

Movies of diffusing ellipsoids, taken by Ken Desmond. movie 1 movie 2

Movie showing motion in a colloidal crystal. 21 minutes of data; the scale bar is 5 microns long; the particles are about 2.2 microns diameter. This is a 2D cut through a 3D colloidal crystal. Data taken by Jessy Hernandez and movie made by Eric Weeks.

A colloidal whirlpool taken by Rachel Courtland. A magnetic blob is rotating in the middle with a period of 1.3 s. Click on the picture to see a 13 s movie. The picture at right is taken by subtracting two images in sequence; it's grey where there is no change, and black/white where there's a lot of motion. (By "blob" we mean a bunch of magnetic particles stuck together in some random irreproducible fashion. To learn about more controlled experiments, click here!.)

Movies of emulsion droplets "popping" and moving around, taken by Charlotte Hollinger. The 3rd movie shows an evaporating region moving into the field of view, and the 4th movie shows little droplets on the coverslip evaporating completely. The droplets are acetate, in a mixture of water and glycerol; the acetate evaporates rather quickly, as this sample was open to air. Each movie shows 2 s of data, except for the 3rd which is 3 s. (droplets popping -- evaporating region -- evaporating droplets)

Simulation of circles moving randomly, from Bayard Bavetta (click on the image for a movie). We're curious to see what colloidal behaviors we can simulate. Note that the circles are different sizes, otherwise they might form crystals, which we're less interested in right now.

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Movie of superparamagnetic particles, taken by Piotr Habdas. When no magnetic field is applied, the particles don't interact (picture at left). When a permanent magnet is nearby, the particles form chains (picture at right). This is the behavior which leads to interesting properties in magnetorheological fluids, which many people have studied -- fluids which become more viscous when a magnetic field is applied. We're not studying magnetorheological fluids; click here to learn what we're using magnetic particles for. Click the pictures to see a movie. In the movie, the chains rotate as the permanent magnet is moved around; the chains break up when the magnet is removed.

Picture of colloids stuck to a glass coverslip; the colloids are a mixture of 1.6 and 2.0 micron diameter particles. The picture at right is slightly out of focus, resulting in the bubble-like visual effect. Taken by Hetal Patel.

We tried coating a coverslip with dried colloids, to create bumpy walls. Our first method for producing bumpy walls left large patches of flat walls where the particles could sit. The fluorescent particles seen are not attached to the wall. Picture from Hetal Patel.

	Microscopic picture of yogurt. The picture is approximately 300 microns wide, and the color was added afterward to make it look more exciting. We're not sure what those floating things are in the yogurt. Taken by Doug Anderson & Rachel Courtland.
	Microscopic picture of catsup, from a small packet we picked up in the Cox Hall cafeteria. We think we see some cellular-looking structure in this picture, perhaps from the tomato. The picture is approximately 300 microns wide. The original picture is actually black & white, but we have recolored it more like what we see under the microscope. Taken by Doug Anderson & Rachel Courtland.

More pictures as we see interesting things. Also, investigate the research projects listed on our home page -- some of them have movies.