Nano-coatings

MAVRO has been active in the development of nano surface technology since the foundation of the company
Sustainable
Self-cleaning coatings
Reduced maintenance costs
Delays degradation

NANO-Coatings

Nano coatings are very interesting for various applications because of their superior properties that are not usually found in conventional coatings. In recent years, there has been a significant increase in available coatings claiming to contain nano particles. Especially within our industry, the use of the term ‘nano’ has increased significantly, sometimes rightly so, but often only as a marketing technique or to appear high-end. MAVRO has been a supplier of various products based on nano particles for years, and handles the use of the term ‘nano’ with awareness. You will only find us using the term ‘nano’ for products that actually contain nano-materials.

The interest in nano coatings materials is due to their remarkable properties that make them attractive for many modern industrial applications. Nanotechnology is a very broad field which has produced many remarkable innovations and discoveries, particularly in recent years. In order to keep things clear, this article will only focus on the applications MAVRO is involved in, namely hydrophobic, hydrophilic, self-cleaning and easy-to-clean nano-coatings for various substrates

Definition and history

Nano materials were defined by the European Commission in 2011 as:

“a particulate material of which at least 50 % of the particles have a size between 1 and 100 nanometers”.[2]

It is difficult to grasp how small a nanometre is. One nanometre is equal to one billionth of a metre or 0.000000001 metres. The size of a nanometer and a millimetre are proportionally the same as a football and the earth!

The most visible and important effect of nano coatings is also directly related to its origin: the ‘Lotus effect’. A German botanist named Wilhelm Barthlott was the first to describe the ‘Lotus effect’ after his research on plant surfaces. This research prompted a collaboration with industry to develop self-cleaning, hydrophobic surfaces. The developments that followed led to the great diversity of nanocoatings that we know today.

Want to read more about the lotus effect?

Properties

Due to the small particle size, nano coatings acquire special and new properties that other types of coatings do not always achieve. Due to the properties inherent in the nanoscale, nano coatings are typically multifunctional, with one or combinations of the following properties:

• Scratch and abrasion resistance
• Good chemical resistance
• UV-resistant
• Optical clarity
• Antistatic
• Good adhesion on different types of materials
• Hydrophobic
• Oleophobic
• Easy-to-clean
• Self-cleaning
• Catalytically active

It is important to know that self-cleaning and ‘easy-to-clean’ are not the same thing.
Easy-to-clean surfaces are surfaces that are easier to clean because of their dirt- and water-repellent properties. These types of coatings are not fully self-cleaning; a shower of rain, for example, is not enough to clean the surface. Periodic manual cleaning is still required. The main advantage of these coatings is that the manual cleaning is less frequent and can be done with less aggressive chemicals.

Self-cleaning surfaces are surfaces that remain clean through active operation. With this type of coating, the dirt is often broken down by the influence of sunlight and washed away by a film of water during the next rainfall. A detailed explanation of self-cleaning coatings can be found later on this page

Common applications

Within MAVRO’s assortment the applications for nano coatings can be divided on the basis of the substrate they are applied to. The MAVRO assortment contains nano coatings for textile, glass, plastics and mineral substrates. The possible applications are endless. Think for example of solar panels, carwashes, textiles and cars.

Click here to read where our nano coatings are applied.

Maintenance after application

Nanocoatings make the maintenance of your substrate or object considerably faster and cheaper. Due to the special repellent properties of the nanocoating, dirt can no longer adhere to the treated surface. This ensures that:

1. You save on cleaning products because less chemistry is needed to achieve the desired result.
2. You save on cleaning intervals because the treated surface stays clean longer. So you clean less often!
3. You save on general cleaning costs. Cleaning of a treated surface is faster, easier, with less water and with less product.

In short, nanocoatings are guaranteed to pay for themselves!

Removal of nano-coatings

Nanocoatings are particularly durable and long-lasting. However, if there is a reason to remove a nano-coating, for example if the product has been applied incorrectly, this is not always easy. Nanocoatings are extremely durable, but like all coatings the thin coating will disappear over time due to ‘wear and tear’.

The removal of a nano coating differs per substrate and product type. Basically, a nano coating must always be removed mechanically, which means sanding, blasting, polishing, etc.

A nano coating on glass and plastic is relatively easy to remove. By polishing the glass with a very fine grain or a Cerium Oxide-based polishing paste, the nanocoating will wear off quickly. This simulates years of wear and tear by external influences, but in a matter of seconds. This method is applicable for our NITOGUARD® GLASS, NITOGUARD® GLASS SC and NITOGUARD® PLASTIC. Always bear in mind that you are using a fine grain that does not cause scratches or dull spots.

Removing a nano coating from textiles is difficult. This is because the nano-coating binds to every fibre of the material, and sanding or polishing is obviously not possible. The mechanical durability of NITOGUARD® TEXTILE is very good, a treated textile can withstand approx. 30-40 wash cycles. Fortunately, removing a nano-coating from textiles is hardly ever necessary. If the water repellent properties decrease after a few years, the textile can be re-treated without removing the previous treatment.

Removing nano coatings from mineral substrates, as well as from glass, can only be done mechanically. MAVROSEAL NANO adheres only to the surface of the mineral substrate (brick, tile, concrete etc.). In order to remove the nanometre-thin coating, it is therefore necessary to remove the top layer together with the coating that is on top of it. On mineral substrates, sandblasting or grinding is often the most efficient method. Fortunately, also for this application, the removal of a coating does not or hardly occur.

Chemistry

How do nano coatings work? Nano coatings can refer to 2 things: a coating with a layer thickness of several tens of nanometers or a coating with Nano-particles incorporated. As mentioned before, MAVRO works with the latter: Nanoparticles in the coating. But why? And how does this?

Every material has a content and a surface. The surface is where materials can react with the outside world. The surface largely determines the properties of a material. Think, for example, of rust on iron and limescale on a shower cabinet; both take place on the surface.

But what does this have to do with nano-particles? Well, a lot! The fact is, the smaller a particle is, the greater the ratio of its surface area to its content. This happens very quickly, see the image below for an example. A container with small blocks has a much larger surface area than a container with large blocks.

You can imagine that nanoparticles have a gigantic relative surface area. This ensures that nano coatings can have very special properties. Titanium dioxide, for example, has a surfacethat absorbs UV light. Titanium dioxide nanoparticles can be found in sun block, for example. Due to the extremely large surface area, the cream can absorb a lot of UV light and protects the skin. The best part is that the particles are so small that they do not absorb visible light, but they do absorb UV light. Therefore, these properties are also excellent for a glass coating, for example!

Safety and sustainability

MAVRO believes that transparency and honesty is the only way to bring new innovations and technologies safely to the market. As a supplier of nano coatings, we try to provide our customers with all the information necessary to work safely and consciously with nano coatings. There are currently no national or European laws and regulations regarding the handling of nano products, therefore we like to take a proactive role in providing information. Please also consult our Product Data Sheets and Safety Data Sheets for the necessary information before use. Should you have any questions regarding the safety and use of nano coatings please contact us directly.

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