POMS & Toxic Chemical Agents
Toxic-Molecule Responsive Catalytic Polymers
Toxic chemical agents, such as Sarin gas, have been heavily featured in recent news reports, which highlight the dangers certain chemical toxins and pollutants pose to human health and well-being. Such chemical agents inspired an Emory research team, led by Goodrich C. White Professor Craig Hill, PhD and doctoral student Kevin P. Sullivan, to develop a chemical compound that detects, absorbs, and detoxifies environmental chemical toxins.
Hill and his team developed an insoluble polymer made up of covalently linked metal clusters, called polyoxometalate ions or POMs. This polymer consists of two primary components: small inorganic metal clusters made up of metal and oxygen atoms covalently bound to organic linkers with multiple hydrogen bonding sites. They found that when certain toxic chemical compounds were added to a powdered form of this polymer, it swells, traps the compound, changes color, and forms a gel. They hypothesized that they could develop this polymer into a material that would trap and then destroy toxic substances, thereby neutralizing them and eliminating the threat they pose to humans.
The polymers detoxify toxic chemical compounds by acting as catalysts, which speed up chemical reactions (including oxidations and hydrolyses) without undergoing any chemical change themselves. In the case of oxidation, the polymer serves to increase the speed at which the oxygen in ambient air oxidizes a toxic agent, removing an electron from that agent and effectively detoxifying it. Although this process does occur when the agent is exposed to ambient air, the process occurs much too slowly to neutralize the threat of the agent to exposed individuals. Hydrolysis reactions are those in which compounds are degraded through introduction of water molecules. The toxic-molecule-responsive catalytic polymers also catalyze hydrolysis reactions, which are especially effective in the case of neutralizing organophosphorous nerve agents like Sarin and Soman.
Furthermore, the use of the Emory team’s polymer is also environmentally friendly. “Both hydrolysis and oxidation are green reactions because they use molecules that naturally occur in the environment, ambient air (O2) or water (H2O),” said Hill. Because the polymers act as catalysts they are reusable and sustainable, and may be regenerated following their use in degrading the toxic compounds.
Hill and his team recently received a grant to continue to expand upon their toxic-molecule responsive catalytic polymers research. They hope to perfect their existing polymer by making it easier to process and translate into certain applications, like self-decontaminating and self-deodorizing apparel, upholstery, carpeting, poured materials and paints. With the grant, they also plan to create a family of such polymers by slightly changing the polymer structural components, thus its properties and broadening the scope of compounds that may be detoxified.
Justin Burns, the Emory Office of Technology Transfer Licensing Associate in charge of this innovation, argued that the toxic-molecule responsive catalytic polymers could have diverse commercial and practical applications. Burns said, “These polymers have the capability to add value to a range of commercial sectors. There are countless possibilities.”
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