Physical Sciences and Mathematics Commons^™

Wrinkling Of A Floating Sheet, Narayanan Menon

Patterns Around Us

The objective of today’s work will be to generate wrinkle patterns on very thin polymer films using the forces generated by the surface tension of a water drop. You’ll do a few sizes of water drop and we’ll give you a couple of thicknesses of film. Digital images of the pattern will allow us to make observations of the number and size of the wrinkles generated. We will try to develop an understanding of the dependence of the pattern on the materials used and the forces applied

Colloids And Emulsions, Tony Dinsmore

Science and Engineering Saturday Seminars

Colloids and Emulsions.

These materials are very common and are amenable to some nice demonstrations, yet are not part of the usual curriculum. Topics include surface tension (and why droplets are spherical; why shaving cream acts like a solid even though it's made of liquid and gas); Brownian motion and the microscopic origin of heat; the behavior of many particles (phase transitions, how colloidal particles can spontaneously order themselves – an accurate demonstration of how water molecules form ice crystals); what is inside everyday materials.