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
Newly designed molecule binds nitrogen
23.02.2018 | Julius-Maximilians-Universität Würzburg
Atomic Design by Water
23.02.2018 | Max-Planck-Institut für Eisenforschung GmbH
A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.
In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...
A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.
By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...
Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
23.02.2018 | Physics and Astronomy
23.02.2018 | Health and Medicine
23.02.2018 | Physics and Astronomy