Textiles with electroplating

Metal nanocoating of fabric fibers to fight bacteria and viruses

Sergey Syrov, XX2 century

An international research team has tested a new method of applying a metal coating to fabric. The coating adheres well to the fibers and shows high antimicrobial and antiviral activity, destroying 99% of pathogens that get on it.

"Microbes can survive on bed linen fabrics in hospitals, on clothes and protective masks for a long time," says one of the authors of the work, a professor at North Carolina State University, a microbiologist Michael Dickey. — Coating with metal, such as copper or silver, is effective against pathogens, but existing technologies for coating metal particles have disadvantages: unevenness, complexity of care, poor adhesion."

Dickey and his colleagues at the university engaged scientists from Sungkyunkwan University (South Korea) and Melbourne Royal University of Technology (Australia) to create a simple and cost-effective method of applying metal coatings to fabric. The progress on this path is reported in an article published in Advanced Materials (Kwon et al., A Liquid Metal Mediated Metallic Coating for Antimicrobial and Antiviral Fabrics).

At the first stage of the process, liquid gallium (Ga) is dissolved in ethanol and exposed to sound waves. In this way, a solution with gallium nanoparticles is obtained. This solution is then sprayed onto the fabric, and the gallium adheres to the fibers after the ethanol evaporates.

Then the gallium-coated fabric is immersed in a solution of copper sulfate, and as a result of the galvanic substitution reaction, copper is deposited, forming a copper nanocoating on the fibers of the fabric.

Experiments have shown that 99% of pathogenic microorganisms falling on the tissue treated in this way die within five minutes. This is shown in three widespread pathogens — Staphylococcus aureus, Escherichia coli and Candida albicans. This is faster and more reliable compared to copper-coated fabrics using technologies already used in industry.

The fabric with a copper nanocoating also has antiviral activity. In the same five minutes, both the influenza virus (H1N1) and the coronavirus are destroyed on it (tested on HCoV 229E).

The researchers claim that their development can be relatively easily scaled to an industrial scale and allows using not only copper as an active element, but also silver.