October 8, 2019
Water makes up more than two-thirds of weight in the human body and nearly 95 percent of the brain. It is essential for life and considered a basic human right. However, each year, tens of millions of Americans are exposed to unsafe drinking water. The concern over clean drinking must extend beyond lead poisoning in Flint, MI, and should address the fact that, even today, unsafe water is often limited to the poorest amongst us.
In an effort to find an alternative to costly laboratory water testing, Walsh Assistant Professor of Chemistry Tim Smith, Ph.D., and several students are exploring a non-invasive, low-cost methodology for heavy metal testing in drinking water.
“Water quality is imperative to human life. In recent years, the identification of hazardous materials, especially heavy metals, ending up in drinking water is unacceptable,” said Dr. Smith. “The methodology for testing of these metals can be both time-consuming and expensive. Currently, I have three Walsh students who have been involved with this project. We are synthesizing the materials needed and will begin testing our theory by running UV-Vis experiments on our systems this upcoming semester.”
Dr. Smith is leading a student team to research the utilization of quasi-water soluble reverse photochromic materials that will work as visual indicators of the metal ions present in a water sample. Similar to the methodology present in transitional lenses in glasses and a simple pool test kit, this process allows for the immediate analysis of the presence of different metals in a water sample while eliminating the need to run multiple tests to determine different metal concentrations.
“The reality is that if it’s a poor area, resources are not allocated to check the water as efficiently as possible. If you’ve ever seen a pool water test kit, it’s the same kind of concept. The color change will indicate the type of metal in your water,” said Dr. Smith. “We are working on creating profiles of every possible metal ion you can find in your water. It would be a real easy and effective method so that you won’t have to send a sample to a lab, have someone test it and wait for results. You can test right in the field by hitting a little button on your handheld machine.”
The quick response will tell field researchers if more extensive testing is required in a lab. The Walsh research team is currently in the exploratory phase.
“We are categorizing all the metals to create profiles of what lead will look like, or iron, etc.,” said Dr. Smith. “We don’t test well water as often as we should. There are home test kits that you can buy at Home Depot or Lowes, but they still depend upon the user. If the user does something wrong, the sample can easily be contaminated.”
While the molecules being studied by the Walsh team have been known for a long time, it has only been in the recent years that scientists have begun looking at different implications beyond transitional lens.
“The molecules are photochromic, which means that light makes them change color. The molecules also become water-soluble. When metal is in water, the molecules will detect it and change color. You’ll be able to see it,” said Dr. Smith. “Before coming to Walsh, I spent 10 years studying how liquid crystals can help create protective eyewear and visors for Air Force pilots. While working with reactive eyewear, I began to think about how this technology could be applied to various uses.”
Liquid crystal elastomers (LCE) can also be effective actuators or “movers” that exhibit muscle-like contractions capable of moving material. However, these materials can wear down over time. The Walsh team is also researching how to implement chemical self-healing properties to LCE materials without effecting their performance.
The research could eventually have healthcare implications in developing macrocyclic cobalt complexes as anti-viral and anti-cancer agents.