Microrockets fueled by water neutralize chemical and biological warfare agents

October 29, 2014
Microrockets fueled by water neutralize chemical and biological warfare agents

With fears growing over chemical and biological weapons falling into the wrong hands, scientists are developing microrockets to fight back against these dangerous agents, should the need arise. In the journal ACS Nano, they describe new spherical micromotors that rapidly neutralize chemical and biological agents and use water as fuel.

Joseph Wang and colleagues point out that is one of the most promising materials available for degrading and biological warfare agents. It doesn't require harsh chemicals or result in toxic by-products. Current approaches using titanium dioxide, however, require that it be mixed in whatever solution that needs to be decontaminated. But there's no way to actively mix titanium dioxide in waterways if chemical and are released into the environment. So scientists have been working on ways to propel titanium dioxide around to accelerate the decontamination process without the need for active stirring. But approaches so far have required fuel and other compounds that hinder neutralization. Wang's team wanted to fix this problem.

To give titanium dioxide a source of thrust, the researchers coated it over a magnesium sphere core. When put in a watery environment, a single hole in the shell allows water to enter and react with the magnesium core. This produces hydrogen gas, which bubbles out and propels the titanium dioxide through the surrounding liquid. This enables it to more efficiently and rapidly contact and degrade harmful agents. When tested, the micromotors successfully neutralized nerve agents and anthrax-like bacteria in considerably less time compared to titanium dioxide microparticles that aren't propelled.

Explore further: Children may have highest exposure to titanium dioxide nanoparticles

More information: "Water-Driven Micromotors for Rapid Photocatalytic Degradation of Biological and Chemical Warfare Agents" ACS Nano, Article ASAP. DOI: 10.1021/nn505029k

Abstract
Threats of chemical and biological warfare agents (CBWA) represent a serious global concern and require rapid and efficient neutralization methods. We present a highly effective micromotor strategy for photocatalytic degradation of CBWA based on light-activated TiO2/Au/Mg microspheres that propel autonomously in natural water and obviate the need for external fuel, decontaminating reagent, or mechanical agitation. The activated TiO2/Au/Mg micromotors generate highly reactive oxygen species responsible for the efficient destruction of the cell membranes of the anthrax simulant Bacillus globigii spore, as well as rapid and complete in situ mineralization of the highly persistent organophosphate nerve agents into nonharmful products. The water-driven propulsion of the TiO2/Au/Mg micromotors facilitates efficient fluid transport and dispersion of the photogenerated reactive oxidative species and their interaction with the CBWA. Coupling of the photocatalytic surface of the micromotors and their autonomous water-driven propulsion thus leads to a reagent-free operation which holds a considerable promise for diverse "green" defense and environmental applications.

Related Stories

Sunblock poses potential hazard to sea life

August 20, 2014

The sweet and salty aroma of sunscreen and seawater signals a relaxing trip to the shore. But scientists are now reporting that the idyllic beach vacation comes with an environmental hitch. When certain sunblock ingredients ...

A nanosized hydrogen generator

September 20, 2014

(Phys.org) —Researchers at the US Department of Energy's (DOE) Argonne National Laboratory have created a small scale "hydrogen generator" that uses light and a two-dimensional graphene platform to boost production of the ...

Recommended for you

Graphene under pressure

August 25, 2016

Small balloons made from one-atom-thick material graphene can withstand enormous pressures, much higher than those at the bottom of the deepest ocean, scientists at the University of Manchester report.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.