Textured surface helps sewage slide smoothly

Reporting in ACS Applied Polymer Materials, researchers evaluated seven different textures made up of microscopic-sized cones to see which ones could repel sewage water the best. In sewage pipes, sticking liquids can gunk up pipes with grime and bacteria, which increases cleaning and maintenance needs. So scientists are interested in developing slippery surfaces to keep pipes clean without relying on harmful chemical coatings that can pollute the environment. The researchers identified two textures that repel sewage water, resist bacterial growth, and are straightforward to manufacture.

Source Article

“Sewage Water-Repellent PDMS and Magnetic Silicone Composites: Lab to Commercialization”
ACS Applied Polymer Materials
Corresponding authors: Sriharitha Rowthu, Ph.D. and Patrik Hoffmann, Ph.D.

Transcript

Narrator: This specially textured surface keeps liquid from sticking and could one day help keep sewage systems flowing smoothly. It only takes a rainstorm or an accidental spill to remind us to be grateful for liquid-repelling surfaces. Liquid-repelling surfaces are essential to many systems we rely on. They can help keep ice off power lines and keep ship hulls clean to reduce drag.

In wastewater systems, sticking liquids can gunk up pipes with grime and bacteria, which increases cleaning and maintenance needs. So researchers wanted to test whether a specially textured surface could repel sewage water, without relying on harmful chemical coatings that can pollute the environment. Sewage water contains solid particles, microbes, and other organic material in addition to water. So the surface would need to repel all of it.

The researchers stamped two different base materials with seven different patterns made up of microscopic-sized cones. Then they tested how well each surface repelled sewage water to identify the best performers. This high-speed footage shows how a droplet of sewage water bounces off the textured surface multiple times before it sticks, which indicates high water repellence. The researchers found their best textures shed water better than other common slippery coatings after being fully submerged. And the spiky texture prevented bacteria from growing to cover the surface.

Next, the researchers plan to study how the most promising surfaces perform over time in more realistic conditions. And whether they could provide a practical way to keep sewage pipes clean. Well, as clean as the inside of a sewage pipe can be.