SSEF Silver Award

Water analysis seeks to identify and quantify the chemical components and properties of a water sample. Current water analysis techniques excel in their niches of application, but there is an increasing demand for cheap, portable monitoring systems that do not compromise on sensitivity. We tested Precision Ellipsometry as a novel water analysis system that satisfies such conditions. Precision Ellipsometry is an optical technique that detects changes in the thickness of thin films on a substrate. We used it to analyse ion concentrations in water from cooling towers in commercial malls. Ions were detected by attaching polyelectrolytes to the substrate and measuring the increase in thickness after ions bind to them. To detect cations, we tested polystyrene sulfonate, and to detect anions, we tested polyallylamine hydrochloride.
From our results, Polystyrene Sulfonate and Polyallylamine Hydrochloride showed strong affinity to cations and anions respectively. Furthermore, Precision Ellipsometry could reliably detect cationic and anionic concentrations as minute as 0.001M in cooling towers. Precision Ellipsometry’s demonstrated sensitivity thus allows detection of critical concentrations before ions precipitate, blocking pipes and impeding the functioning of crucial mechanical components in the water. We revealed the dependence of trends in ionic concentrations on the time of year, climate, temperature, and activity levels at the locations of cooling towers, providing valuable information to help maintain the towers. Therefore Precision Ellipsometry is a viable water analysis system that could have a myriad of applications in any field that requires low-cost, portable and sensitive water analysis.