Visualizing Marangoni Flow. Intermolecular forces and surface tension gradients in solutions lead to Marangoni flows, where liquid flows from a region of low surface tension towards higher surface tension. Details of these flows, not visible to the naked eye, are made visible on an overhead projector owing to variation in the index of refraction. The demonstrations described in the article by Mundell use Marangoni effects to create images on the overhead projector simulating flowers, an evil eye, and a zen garden. In the image on the cover, a floral pattern emerges as acetone evaporates from the dyed Marangoni solution generating a colorful surface tension gradient. The ideas behind these surface tension flows solidify understanding of intermolecular forces and lead to a discussion of intermolecular forces, properties of liquids, surface tension, and Marangoni effects.
Our Secondary School editors work hard to distill all the JCE materials to produce a fraction of particular interest to high school teachers. We call it CLIC.
In recent years we have worked hard to better match our advertisers with our readers. When shopping for chemistry education materials, visit our advertisers' WWW sites first.
Take JCE along on your outreach missions. Copies of the Journal, guest access to JCE Online, our publications catalog, and more are available for your participants.