Designing Polymers to Clean Water
A yellow membrane filters water (red circles) and leaves behind some unwanted particulates (blue circles and green triangles).Copyright Drahkrub 2009, Public Domain, Wikimedia Commons https://commons.wikimedia.org/wiki/File:Dead-end.svg
Students learn the concept behind the engineering design of a polymer brush—a coating consisting of polymers that is “tethered” to a particular surface. Polymer brushes can be used on water filtration membranes as an antifouling coating. After designing a model that represents an antifouling polymer brush coating for a water filtration surface, students take on the challenge to engineer their brush design on the surface of a Styrofoam block (which serves as a model for a surface filter) using various materials.
Engineers who work in fields such as plastics, chemistry, physics, and biology often work together to develop sustainable solutions for the environment; in particular, water quality. For example, engineers may be tasked with the design of coatings that control interactions between a surface and an environment. These designs are called antifouling coatings which are used in a range of applications, from medical devices and biological implants to wastewater plants and shipping hulls. In this activity, students learn how to make an antifouling coating for a model water filtration membrane. Students employ the engineering design process as they attempt to develop a brush filter system to prevent fouling. Each group will be provided opportunities to test their design and then make improvements based on its performance.
After this activity, students should be able to:
- Predict how changing a component of their design might improve or impair its properties.
- Explain the thinking behind their engineered solutions.
- Test the design for functionality.
- Collaborate in groups to create the best design from a collection of individual designs or features.
- Examine the successes and shortcomings of a design and further iterate upon it.