Scientists invent ‘superfoam' that can kill bacteria and soak up oil spills

The material can be used in environmental disasters and implanted medical devices.
Loukia Papadopoulos
The material could be used in oil spills.jpg
The material could be used in oil spills.

onuma Inthapong/iStock 

Researchers at the University of Georgia have invented a material they call a “superfoam” that could both reduce infections caused by implanted medical devices and aid in cleanup efforts following environmental disasters such as oil spills.

This is according to a press release by the institution published on Wednesday. 

The scientists compared the new material to a “spongy Swiss Army knife” and described it as water repellent.

“Making a multifunctional and versatile surface is an extremely challenging task,” said Hitesh Handa, an associate professor in UGA’s School of Chemical, Materials and Biomedical Engineering. 

“You can find a surface that is only antimicrobial, or you can find one that can only prevent blood clotting. To be able to fabricate materials that are anticlotting, antimicrobial and antifouling is a significant improvement on current standards.”

To engineer the material, the researchers took a coarse foam and added the following fillers: hydrophobic (or, water repellant) electrically conductive graphene nanoplatelets and hydrophobic bactericidal copper microparticles. 

Experiments yield positive results

In experiments using E. coli as a test bacterium, the researchers found that the material resulted in a 99.9 percent bacterial reduction over a simple polymer. This means it has the potential to improve health outcomes for the more than 500,000 patients who suffer from health care-related infections due to medical implants each year.

“Current medical devices are prone to contamination,” Handa said. “When you put any medical device into the body, proteins are the first thing to stick to a surface, and they act like a glue that allows blood or bacteria to adhere. So, if we can stop the protein adsorption, half the battle is won.”

Further tests where the foam was placed into a variety of water mixtures, showed its ability to absorb and remove the organic pollutants from the water, while also killing bacteria in the water itself.

“The versatility is the key here,” said Mark Garren, a co-author on the paper and doctoral student in Handa’s lab. “The multifunctional properties are what inspired this, then developing that and showcasing all of its abilities.”

Currently, the main goal for the researchers is to apply the surface to medical devices and demonstrate its effectiveness before moving on to non-human animal trials and, eventually, testing in humans, noted the statement. Meanwhile, the material could be already used in environmental cleanup use cases as these face less rigorous safety standards.

The study was published in the journal ACS Applied Materials & Interfaces.

Study abstract:

Hybrid organic–inorganic materials are attracting enormous interest in materials science due to the combination of multiple advantageous properties of both organic and inorganic components. Taking advantage of a simple, scalable, solvent-free hard-sacrificial method, we report the successful fabrication of three-dimensional hybrid porous foams by integrating two types of fillers into a poly(dimethylsiloxane) (PDMS) framework. These fillers consist of hydrophobic electrically conductive graphene (GR) nanoplatelets and hydrophobic bactericidal copper (Cu) microparticles. The fillers were utilized to create the hierarchical rough structure with low-surface-energy properties on the PDMS foam surfaces, leading to remarkable superhydrophobicity/superoleophilicity with contact angles of 158 and 0° for water and oil, respectively. The three-dimensional interconnected porous foam structures facilitated high oil adsorption capacity and excellent reusability as well as highly efficient oil/organic solvent–water separation in turbulent, corrosive, and saline environments. Moreover, the introduction of the fillers led to a significant improvement in the electrical conductivity and biofouling resistance (vs whole blood, fibrinogen, platelet cells, and Escherichia coli) of the foams. We envision that the developed composite strategy will pave a facile, scalable, and effective way for fabricating novel multifunctional hybrid materials with ideal properties that may find potential use in a broad range of biomedical, energy, and environmental applications.