Nanosilver biocidal coatings in the form of thin film coatings or paints have the effect of reducing mold and mildew as well as acting as anti-bacterial agents. These attributes make these coatings useful in medical applications for keeping equipment and surfaces sterile. The antimicrobial properties of these biocidal coatings are also important in industrial and commercial settings where harmful microbes may be present. They also extend the life of building materials by inhibiting the growth of molds and mildews that are harmful to human health.
Topasol Antimicrobial Biocidal Coatings, still in the engineering to commercialization stage, are about 170 nanometers thin and contain clusters of silver nanoparticles in an organic silicon matrix. The silicon has anti-adhesive properties, which work with the broad spectrum antimicrobial properties of nanosilver to create a new generation of nanocoatings that lose fewer silver nanoparticles to the environment through normal weathering. This breakthrough alleviates some of the sustainability and environmental challenges of using silver nanoparticles in widespread applications.
Topasol Antimicrobial and Biocidal Coatings are adhered to surfaces via Plasma-Enhanced Chemical Vapor Deposition (PECVD), a technique that is a derivative of Chemical Vapor Deposition (CVD). This process involves suspending the organosilicon and nanosilver particles in a gas between two electrodes, creating an ionized plasma. The surface to be coated is then introduced to the plasm in the reactor and is subsequently bombarded with the ionized gases, creating a substrate coated with a thin film.
- . Plasma-Mediated Nanosilver-Organosilicon Composite Films Deposited on Stainless Steel: Synthesis, Surface Characterization, and Evaluation of Anti-Adhesive and Anti-Microbial Properties on the Model Yeast Saccharomyces cerevisiae. Plasma Processes and Polymers. 2011 ;9(3):324 - 338.
- Antimicrobial Biocide Coating. [Internet]. 2012 . Available from: http://www.topasol.com/biocidal.html
- . Plasma deposition of organosilicon polymer thin films with embedded nanosilver for prevention of microbial adhesion. Applied Surface Science. 2009 ;256(3):S35 - S39.
Studies conducted on paint containing silver nanoparticles have shown that about 30% of silver nanoparticles in the coating enter the environment within one year of application. These particles then enter the aquatic environment as runoff. The toxicity of the particles in the environment depend on the speciation of the silver—whether or not the silver is dissolved in its ionized form or quickly forms solid compounds with sulfur or other organics. This risk is diminished in plasma deposition of nanosilver particles that are suspended in organosilicon thin films because these films are designed to reduce migration of the silver nanoparticles. Additionally, the plasma deposition process used in the Topasol anti-microbial biocide coatings occurs in s singular process, containing open exposure to silver nanoparticles to a single manufacturing process rather than multiple processes in a long supply chain. This reduces the number of steps in the fabrication process where ecological and human contact with silver nanoparticles can occur.