Rapidly and efficiently converting chemical weapons into nontoxic products in remote areas is one of the most difficult tasks in the disposal of weapons of mass destruction.
In the journal Angewandte Chemie, a team from the University of California, San Diego has now described how self-propelled micromotors can accelerate the oxidative neutralization of nerve agents by intensively mixing the remediation solution.Environmentally friendly processes that use hydrogen peroxide and an activator (e.g. sodium bicarbonate) to degrade chemical weapons like sarin, VX, soman, and mustard gas have recently replaced earlier chlorine-based methods. However, they generally require high concentrations of peroxide, long reaction times, and intensive mechanical mixing—which can be extremely problematic in the elimination of stocks of chemical weapons in remote regions or enemy camps.
A team headed by Joseph Wang has now developed a novel strategy based on mixing of the remediation solution with self-propelled micromotors.
The motors are tiny conical tubes made from a bilayer with a polymer on the outside and platinum on the inside. In this process, hydrogen peroxide acts as both the oxidizing agent for the chemical weapons and fuel for the micromotors. As the hydrogen peroxide is catalytically decomposed on the inner platinum surface, oxygen bubbles are formed.
The bubbles exit the tubes at their rear (wider) end, pushing them through the liquid. The movement of the motors through the liquid combined with the gas bubbles provides for efficient mixing of the remediation solution. This significantly increases both the turnover and the speed of the decontamination reaction without requiring high concentrations of peroxide.
Wang’s team was able to demonstrate the efficiency of their new method by breaking down a variety of organophosphate pesticides with chemical structures similar to those of organophosphate nerve agents. In a demonstration reaction, 1.5 million micromotors in a volume of about 15 mL achieved mixing comparable to a magnetic stirrer at 200 revolutions per minute.
The concept of mixing through the movement of self-propelled micromotors is not limited to the neutralization of chemical weapons. It could also be used to accelerate chemical reactions in general. This could be useful in applications like microreactors, where mechanical mixing is often difficult.About the Author
Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201308072
Joseph Wang | Angewandte Chemie
Fish recognize their prey by electric colors
13.11.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn
The dawn of a new era for genebanks - molecular characterisation of an entire genebank collection
13.11.2018 | Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly
The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
13.11.2018 | Life Sciences
13.11.2018 | Life Sciences
13.11.2018 | Awards Funding