Value-Added Catalysts and Nano-Treatments

Complementing material replications, colors, textures, and graphic effects, notable technological advancements are occurring in the realm of catalysts and nano-treatments to improve the health and safety properties of ceramics.

“We have seen an uptick among clients who are requesting measures to provide antimicrobial products into specifications,” confirms Waldrop.

“We have been following the progress in coating ceramic tiles with nanoparticles to create benefits such as self-cleaning and decomposition of pollutants,” observes Gwin. “This becomes very appealing to healthcare and medical environments in particular and can reduce the need for chemical cleaning products that can be detrimental to the environment.”

Eyink notes that the pandemic has increased our collective sensitivity to clean spaces. “Not only does the space need to be clean, it must appear clean,” she says. “In the case of healthcare, the perception of a clean environment directly impacts patient satisfaction.”

She adds that nano-coatings on surfaces provide an extra layer of durability, protect the surface, repel liquids, and improve color vibrancy. “I typically turn to materials like treated ceramics when working with clients who desire the highest performing products on the marketplace because of their functionality to eliminate staining and slipping,” she relates.

Photocatalytic technology capitalizes on the reaction between natural light and oxide catalysts which are encapsulated in a ceramic glaze. The result is a self-cleaning tile that repels dirt and causes water to run off more easily.

When sunlight or certain LED lights shine on the tiles, the titanium dioxide or other proprietary mineral compound particles baked into the glaze are activated and use the light energy to transform moisture in the air into oxidizing agents. This then destroys contaminating agents such as nitrogen dioxide particles and organic contaminants such as bacteria or mold and chemically transforms them into harmless water vapor and salt. This photocatalysis process is repeated millions of times per second until all contaminants are destroyed, giving the surface its self-cleaning properties.

The process causes water to expand evenly across the surface to more easily remove any dirt or other particles. For paver applications, as rainwater drains, the surface is left completely clean without water marks. This often eliminates the need for exterior building cleaning and the use of harmful cleaners.

Because the nano-treatment is not a coating, but rather baked into the glaze/body of the tile, this changes the hydrophilic properties of the surface, creating greater surface tension, making water sheet off the surface and allowing traffic better purchase on the surface, improving slip resistance in both wet and dry areas.

In addition to the nanoparticles, structural molds and molecular modifications to glazes’ sintered surfaces can be applied to make tiles even more slip-resistant when wet than when dry. These ceramic and porcelain tiles can have smooth and even a few semi-polished surfaces as well as textured surfaces. The application of these technologies produce safe and traffic-resistant tile flooring that is comfortable on the feet and easy to clean in almost any environment.

The tile feels smooth on the surface, yet provides a high level of surface resistance. Delivering the level of safety performance required in outdoor areas, the application of these technologies further enables designers to achieve the simplified, cohesive look of designing the same flooring for the interior and exterior for visual and technical continuity.

Proven to repel mildew, mold, and bacteria, some of the latest technologies are also pursuing antiviral certification. In fact, the Tile Council of North America’s (TCNA) Product Performance Testing Laboratory recently announced that it is expanding its microbiology-based services in light of increased testing inquiries during the COVID-19 pandemic.

New services include antiviral testing to determine the survival rates/duration of viruses on different surface materials and the efficacy of common household cleaners to disinfect these surfaces. TCNA is also joining the ASTM task force to develop surrogates for SARS-CoV-2 virus for testing purposes.

Ceramics and The Structural System

As a long-term system and as an integral aspect of a building’s operational systems, architects and owners can design for ceramics much more effectively if they are considered early on in a project’s design phase.

However, this involves a shift in mindset as ceramics are traditionally treated as finish items like paint, cabinetry, and upholstery, which are only specified after the structural and dimensional decisions have been determined.

“We need to stop thinking of tile as just another finish. The life span, maintenance, and replacement frequency of these other materials aren’t even in the same ballpark so why are we lumping them all together?” asks Fasan. On the contrary, “if ceramics become seen as an integral organ of the building’s operational systems, it is much more cost-effective and provides more benefits.”

For example, if ceramics are specified at the structural design phase, then the walls can be right sized so that large-scale ceramic modules fit with as few cuts as possible, and the ceiling height is the right height for the wall panel size. In optimizing these specifications, the installation time and effort will be much more cost-effective and efficient.

For ceramic flooring, issues like screeds and substrate tolerances can be accounted for early on. And because the ceramic is weather-resistant, very sturdy, and scratch-proof, the tile can be installed even before the walls go up. Tile setters don’t need to worry about tiling themselves into corners and can save time in the install process. Also, in the absence of walls, it’s much easier to move the ceramic tiles into the space prior to installation, especially when it comes to be behemoth formats of gauged porcelain panels and slabs.

As per the TCNA Handbook for Ceramic, Glass, and Stone Tile Installations, the substrate needs to meet proper stiffness and deflection criteria for ceramic installations, the latter of which is defined as potential movement which the installation may experience when subjected to load and use. Because ceramic tiles are rigid and therefore not be able to handle excessive movement in the substrate, the substrate must meet the maximum allowable deflection rating of L/360. Naturally, it’s much easier to ensure that the substrate meets this requirement early in the design and construction process.