What is Nano Coating?
Nano-coating, also known as a ceramic coating is the process of applying a surface layer that repels dry particles, water, oil and dirt.
They can be found in both liquid and solid form and provide characteristics that are favourable. For instance, a nano coating can make a surface scratch resistant, improve hardness, or make it resistant to bacteria.
Nano coatings offer significant benefits for applications in the aerospace, defence, medical, marine, and oil industries, and have driven manufacturers to incorporate multi-functional coatings in their product range.
In simple terms Nano coating refers to very fine, thin layers of polymeric chemical substances (extremely thin layer of microscopic particles is used to fill up every pore of a material’s surface) used to impart specific corrosion resistance, chemical and physical properties to a substrate surface.
How does Nanotechnology work?
When nano particles are applied to a surface, the random particles self-organise in a way that binding components adhere to the surface material and anti-adhesive components are directed outwards forming the top of the nano layer.
This self-organisation forms an ultrathin, invisible layer that is extremely durable and repels liquids. Contaminants such as dirt particles will sit on top of this coating but are easily wiped away with a damp cloth or simply by the rain.
The size of these nano particles is incredibly small, measured in the nano scale, they are no more than 5 or 6 atoms.
This is thousands of times smaller than conventional coatings allowing them to fill cracks and crevasses in surface materials like glass that can only be seen under an electron microscope.
On porous materials like timber, stone and fabric, they form a protective layer around the fibres of these substrates as well as penetrate into the pores of the substrate, spreading out and giving that material even more strength and protection.
Whilst being incredibly small, these nano coatings will still allow air molecules to pass through enabling natural materials to “breath”.
They do not alter the look or feel of materials making them useable in a wide variety of situations and across a wide range of surfaces.
Types Of Nano Coating
#1. Anti-corrosive coatings. When applied to a metal, the coating stops chemical compounds coming into contact with corrosive materials, this stops processes like oxidation.
#2. Waterproof and non-stick clothing. A hydrophilic coating can be applied to various pieces of clothing, whilst the non-stick has applications in furniture, electricals and glass.
#3. Antibacterial coating. These coatings help to inhibit the growth of microorganisms, which is particularly suitable for areas such as public transport.
#4. Thermal barrier coating. This type of coating is particularly prevalent in the aviation industry and is normally applied to metallic surfaces. The elevated temperatures that planes work at have opened up the possibility of the coatings’ use in high powered automobiles.
#5. Anti-abrasion coatings. The main application of this coating is to prolong the life cycle of the surface by lessening the amount of friction that occurs.
#6. Self-healing coatings. The filled nano-capsules inside this coating help repair the surface should any scratching occur. They can be found in everyday items including phones and automotive paints.
#7. Anti-reflection coatings. This coating does not increase transmission, rather it just reduces the reflection on the incident side
#8. Anti-graffiti coatings. These are invisible to the naked eye and prevent costly expenditure to the government and companies in cleaning up graffiti.
Main Nano Coating Techniques
There are many techniques to accomplish the atomistic/molecular deposition on a given substrate: physical vapor deposition (PVD), chemical vapor deposition (CVD), electroplating, electroless plating, laser vaporization, plasma enhanced chemical vapor deposition (PECVD), etc.
#1. Sol gel.
This technology is being increasingly used for the development of optical sensors and biosensors, due to its simplicity and versatility.
Sol-gel material is chemically, photochemically, thermally, and mechanically stable; optically transparent.
It can be cast as various forms including monoliths, thin films, fibers, and powders. This allows various configurations of sensing elements for different applications.
#2. Self-assembly.
It is a process where atoms, molecules or nanoscale building blocks spontaneously organize into ordered structures or patterns with nanometer features without any human intervention. It is the most promising practical low-cost and high-throughput approach for nanofabrication.
#3. Dip coating.
Main advantage of dip coating over other processing techniques is the simplicity of its design. It is low-cost to set up and maintain, and can produce films with extremely high uniformity and a roughness of nanometres.
When the process is optimised, dip coating can be used to produce highly uniform films. Importantly, key factors such as film thickness can be easily controlled.
#4. Spin coating.
This technique is used to prepare uniform thin films in the thickness range of micrometer to nanometer.
The substrate is mounted on a chuck that rotates the sample, and the centrifugal force drives the liquid radially outward. One advantage to spin coating is the uniformity of the film thickness.
#5. Plasma or ion-beam assisted.
This novel technique is used for the production of optical coatings. This technique is known to improve the properties of thermally evaporated thin films.
Electrochemical deposition: It is one of the most useful approaches to prepare nanostructured oxygen reduction rate electrocatalysts.
Using this method, the structures, shapes and sizes of the electrocatalysts can be controlled on the surface of conducting materials by altering the conditions of electrochemical deposition.
#6. Vapor deposition.
This is a chemical process used to produce high-purity, high-performance solid materials. The process is often used in the semiconductor industry to produce thin films.
In a typical process, the substrate is exposed to one or more volatile precursors, which react and/or decompose on the substrate surface to produce the desired deposit.
Frequently, volatile by-products are also produced, which are removed by gas flow through the reaction chamber.
#7. Pulsed laser deposition.
PLD is a thin-film deposition technique using high-energy laser pulses to vaporize the surface of a solid target inside a vacuum chamber and condensing the vapor on a substrate to form a thin film up to a few micrometres in thickness.
In the PLD technique a high pulse energy laser beam, preferably the rectangular profile of a short wavelength excimer laser at 248 or 193 nm, is demagnified on the target material which is to be deposited.
#8. Magnetron sputtering.
The principle of Sputtering is to use the energy of a plasma (partially ionized gas) on the surface of a target (cathode), to pull the atoms of the material one by one and deposit them on the substrate.
Magnetron sputtering is the most widely used method in microelectronics for producing metal layers.
How are nano coatings used?
Nano coatings are used across many industries and fields. That includes electronics, medical equipment, industrial manufacturing, transportation and aerospace.
When properly formulated, they can prevent fingerprints from forming on automotive surfaces and prevent harmful bacteria from growing in medical settings to helping clothing repel moisture.
Because they are typically transparent, nano coatings useful in applications where opacity would be a problem. For example, certain nano coatings can make windows resistant to heat and UV rays.
The window stays clear but gains the additional properties. Today, researchers are using nano coatings to solve many common problems and challenges. From pharmaceuticals to paints, they’re appearing in a huge variety of applications.
Applications Of Nano Coating
Today, nanocoating has catapulted to the very top–figuratively as the best coating, and literally as the optimal top coating in its many fields of application.
Their application surfaces are unlimited and are used in a wide range of sectors from textile to automotive: painted surfaces, glass, ceramics, metal, wood, plastic, mineral surfaces.
One of the key benefits of nano coatings is their outstanding durability.
#1. Textile industry.
Application of nanotechnology in textile manufacturing has led to the introduction of fabrics with excellent chemical resistance, mechanical strength, water repellency, antibacterial properties, and many other properties.
#2. Automotive & aviation.
Ceramic coating and waterproofing is one of the most frequent applications of nanotechnology in automotive.
Nano coatings increase the lifetime of the working material, while reducing the dissipation of energy as heat, thus increasing the efficiency and also play a key role in the performance of internal mechanical components.
A ceramic coating for a car, a boat or a plane offers many advantages. Nanocoating keeps the paint and all other surface areas save from dirt, scratches, corrosion, UV-rays and more.
#3. Construction industry.
Due to self-assembly effect, it represents remarkable characteristics against environmental agents compared to conventional coating materials in the construction industry.
They also show high performance in terms of energy efficiency, CO2 emission, and the air quality improvement.
Considering all these benefits today, nano coatings are the most promising high-performance materials for construction applications.
#4. Food and pharma industry.
Nanotechnology has found many applications in the food and pharma industry as new tools for pathogen detection, disease treatment delivery systems, food packaging, and delivery of bioactive compounds to target sites.
With special antimicrobial coating, nano coating and waterproofing we can address many important issues.
#5. Some Common Types And Applications.
Anti-corrosive coating, Waterproof and non-stick clothing, Antibacterial coating, Thermal barrier coating, Anti-abrasion coatings, Self-healing coatings, Anti-reflection coatings, Anti-graffiti coatings.
Pros and Cons of Nano Coatings
Advantages of nano coating
- Self-Cleaning: Surfaces stay clean, saving time and resources otherwise spent on maintenance. For instance, nano coating gives the paint an excellent. ‘Easy-clean’ and ‘stain-resistant’.
- Corrosion resistance: Surfaces protected by nano coatings have little to no visible corrosion for an indefinite period.
- Scratch resistance: Nano coating gives superior hardness, ideal for use on delicate surfaces like car paint, prescription eyeglasses, and medical and scientific instruments
- Water repellent: Ensures clear vision and safety for transparent surfaces. Also protects surfaces prone to water damage, like textiles, woods, plastics, painted surfaces, and metals.
- UV protection: Nanoparticles effectively filters harmful UV rays
Disadvantages of nano coating
Although this product solves many problems, it has many disadvantages such as:
- High-priced.
- Takes a long time to be applied by a specialized skilled team.
- Some centers can scam the customer and use a non-original product.
- Doesn’t protect the car from some damages caused by water and harmful sunlight.
- Doesn’t prevent dirt from sticking to the car completely but rather makes it easier to clean.
- Doesn’t protect against fire burns.