Researchers have found a way to use magnetic nanoparticle clusters to punch through biofilms to reach bacteria that can foul water treatment systems.

The nanoclusters then deliver bacteriophages—viruses that infect and propagate in bacteria—to destroy the bacteria, usually resistant to chemical disinfection.

Without the pull of a magnetic host, these “phages” disperse in solution, largely fail to penetrate biofilms and allow bacteria to grow in solution and even corrode metal, a costly problem for water distribution systems.

The Rice University lab of environmental engineer Pedro Alvarez and colleagues in China developed and tested clusters that immobilize the phages. A weak magnetic field draws them into biofilms to their targets.

“This novel approach, which arises from the convergence of nanotechnology and virology, has a great potential to treat difficult-to-eradicate biofilms in an effective manner that does not generate harmful disinfection byproducts,” Alvarez says.

Biofilms can be beneficial in some wastewater treatment or industrial fermentation reactors owing to their enhanced reaction rates and resistance to exogenous stresses, says graduate student and co-lead author Pingfeng Yu.

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By using one of the world’s most powerful electron microscopes, a team of researchers from Lawrence Berkeley National Laboratory has successfully mapped the exact location and chemical type of 23,000 atoms in a nanoparticle made of iron and platinum. The team believes this work could reveal more information about material properties at the single-atom level, opening the doors to improving magnetic performance for next-generation hard drives.

“Our research is a big step in this direction. We can now take a snapshot that shows the positions of all the atoms in a nanoparticle at a specific point in its growth,” says Mary Scott, who conducted the research. “This will help us learn how nanoparticles grow atom by atom, and it sets the stage for a materials-design approach starting from the smallest building blocks.”

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The Electrochemical Society’s Vilas Pol, along with a team of Purdue University researchers, has developed a nanoparticle network that could produce very fast-charging batteries.

This new electrode design for lithium-ion batteries has been shown to potentially reduce the charging time from hours to minutes, all by replacing the conventional graphite electrode with a network of tin-oxide nanoparticles.

This from Purdue University:

The researchers have performed experiments with a “porous interconnected” tin-oxide based anode, which has nearly twice the theoretical charging capacity of graphite. The researchers demonstrated that the experimental anode can be charged in 30 minutes and still have a capacity of 430 milliamp hours per gram (mAh g−1), which is greater than the theoretical maximum capacity for graphite when charged slowly over 10 hours.

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