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Silica-Based Nanocoating Hailed as Major Advance in Antimicrobial Technology

Friday, June 10, 2011

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A nanomaterial described as “liquid glass” and billed as a safe antimicrobial coating solution has been chosen to receive the Frost & Sullivan EU New Product Innovation Award in the field of antimicrobial nanocoatings.

The award recognizes the development of the technology by Nanopool GmbH, based in Schmalbach, Germany. The company says it is a developer of coating materials based on silicon dioxide, or silica (SiO2), which occurs naturally as sand or quartz.

“This solution effectively addresses the industrial need for a safe antibacterial coating solution that can be conveniently applied on any surface,” Frost & Sullivan said in announcing the award.

“Additional benefits such as heat resistance, hydrophobicity and flexibility further underline its appeal,” Frost & Sullivan Research Analyst Ankit Ashokkumar Shukla said in the firm’s announcement on the award. “Ease of application and the ability to be customized to suit the needs of specific applications and industries highlights its potential to replace existing antibacterial coating products.”

The award is part of Frost & Sullivan’s “Best Practices Awards” program, which recognizes companies in a variety of regional and global markets for demonstrating “outstanding achievement and superior performance in areas such as leadership, technological innovation, customer service, and strategic product development.”

Nanopool GmbH

Medical personnel at SHG Hospitals in Völklingen, Germany, shown applying the “liquid glass” coating during a test program.

‘High Disinfectant Properties’

In its announcement on the Nanopool award, Frost & Sullivan said the application of silicon dioxide at a nanometric scale as an antimicrobial coating contributes to “high disinfectant properties, previously achieved only by silver nanocoatings.” The announcement adds that while the potential toxicity of silver has been an area of concern, “liquid glass, the nano silicon dioxide product, has been subjected to several clinical tests and found to be compliant with DIN EN ISO 10993-(1-12) standards and hence completely biocompatible.”

The material also is reported to offer water and dirt repellence, which facilitates cleaning, and transparency that retains the aesthetics of the treated surface. The material is reported to resist heat and cold, with functionality at a wide range of temperatures (-150 to +450 C). Long-term durability is also claimed.

Application is by wiping or spraying onto the surface, with potential uses said to span a wide range, from plant protection for agriculture to use in high-tech industries such as aerospace and biomedical. These likely uses extend to building and construction, automotive, production, packaging, transport, retail, and hospitality.

‘Miracle Spray-on Glass’

Applications of Nanopool’s silcon dioxide nanomaterial are reviewed in postings on the company’s website (www.nanopool.biz). The reports include details on a trial at SHG Hospitals in Völklingen, Germany, where a reduction in bacteria of up to 50% and more was demonstrated on surfaces treated with the coating.

A news article in the International Independent (UK), carrying the headline “The Miracle Spray-On Glass That Stops the Bugs” reported on a trial at Alder Hey Children’s Hospital in Liverpool, England, involving application to toys in the children’s wards.

“The liquid glass, which is safe and completely inert, forms an invisible, flexible coating on the surface of an object and repels dirt and grime,” the article states. “More importantly, it is believed to prevent the build-up of hospital-acquired infections such as the superbug Staphylococcus aureus, which is resistant to many antibiotics.”

Tests carried out at another hospital indicated that application of the coating to floors, bedside tables and other surfaces reduced bacteria by 25% to 30%.

Comment from Jim Deardorff, (6/14/2011, 7:43 AM)

I have been studying nanocoatings for the last 16 months. There ability to protect OEM and industrial coatings against weathering, sunlight, chemical and biological attack looks very interesting. The one major problem I see with their use is nanoparticles are extremely small (less than 1/500 the thickness of a human hair. To work effectively they require an extremely clean and contamination free surface. For this new technology to succeed it seems to me that a new cleaning process needs to be developed that matches the performance standards of these new materials. Jim Deardorff

Comment from Jim Haig, (6/14/2011, 4:50 PM)

So far nothing I have seen in their literature or press releases could not be achieved by a silicone polymer possibly "nano-ized" with fine silica powder. If the silica is crystalline (their press release is vague on this respect, it may be simply using the "natural" quartz sand tag) the product has the potential to be carcinogenic if breakdown ends up generating airborne dust. I note there is no MSDS for the product - always a point of concern when these type of products are released with a fanfare. For me the jury will stay out until some critical, well-documented testing of its claims is published.

Comment from Brendan Duffy, (6/15/2011, 8:33 AM)

As a Research Manager working in the area, the technology here is well known in the academic world. It simply involves starting with silicon based monomers, hydrolysing them under acidic/basic conditions and letting them age. The average colloid formed can be anywhere from 2 to 50 nm, which is then easily coated on any surface. During the reaction, functional additives (antibacterial in this case) can be added in. Depending on the porosity of the coating formed, these coatings can leach the additive when challenged. There are several papers available on this and several companies spinning out of the universities exploiting the technology. A quick google search "antimicrobial silver sol-gels" will give any interested reader plenty of material.

Comment from Tom Schwerdt, (6/15/2011, 9:09 AM)

Brendan - thanks for the lead on more solid information for this technology area.