Technology Non-stick coating thwarts mould and bacteria

Non-stick coating thwarts mould and bacteria

Hospitals and the construction and marine industries could reap the benefits of a new type of coating for steel products according to researchers from University of Wollongong (UOW).

The build-up of organisms such as mould, algae and bacteria wreaks havoc on steel products – leading to the need for regular and expensive cleaning and maintenance.

In the marine industry, for example, algal growth can stick to boat and ship hulls, resulting in decreased speed and manoeuvrability as well as increasing fuel consumption.

In hospitals, bacterial contamination of surfaces such as countertops, surgical tools, and medical devices contributes to the spread of potentially deadly hospital-acquired infections.

Currently, the only way to deal with the problem involves coatings that incorporate biocides, which release antimicrobial agents to kill target microorganisms. The problem with this is that many biocides are made with toxic chemicals.

But this could change. Instead of directly targeting microorganisms, the researchers looked at developing a coating that prevented them attaching to a surface in the first place.

They combined silica nanoparticles with chemical compounds which are naturally hydrophilic, or able to bond to water. The nanoparticles are then readily attached to a surface to form a water layer or coating.

“This water layer actually forms a barrier, preventing interactions with proteins, which are often a precursor to organism attachment and subsequent biofouling,” PhD student Brianna Knowles said.

“Microorganisms can’t displace the bound water and so they’re not able to form an attachment to the surface,” she said.

“Hydrophilic coatings also don’t pose the risk of environmental contamination and don’t promote the emergence of biocide or antibiotic-resistant organisms.”

In lab tests, the particle coatings showed an 87 per cent reduction in adhesion of microbial spores and a 96 per cent reduction in bacteria (Escherichia coli).

These results indicate the potential for the silica nanoparticles to be further developed as versatile fouling-resistant coatings for widespread coating applications.

“At this stage, it could be coated directly onto an existing surface to provide fouling protection but further work could be devoted to trying to incorporate nanoparticles with hydrophilic chemistries into paints,” research supervisor Dr Paul Molino said.

Read more about this innovative research here. Story credit: University of Wollongong newsroom.

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