Due to how often surfaces get exposed to the elements, scratched, or otherwise damaged through use, people are interested in how self-healing paint and coatings could keep finishes looking like new for longer. However, they’ll get the best results by taking that approach in the most appropriate circumstances.

Create Coatings that Add Water Resistance

Liquid coming into contact with surfaces that can’t tolerate it could ruin materials or adversely affect a product’s performance. However, self-healing, water-resistant coatings have numerous practical applications across industries.

In one example, researchers worked at the nanoscale level to make extremely thin self-healing coatings with water-resistance characteristics. The team confirmed that the repair time frames for coated surfaces that suffer damage are so fast it’s hard to measure in real time.

These innovative coatings have a dynamic bond network that gives them rapid evaporation qualities. One of the goals of this work was to make steam power plants more efficient. The team worked on this aim by applying their coatings to condenser surfaces, which indicated they increased the condensers’ water resistance and promoted water droplet formation. These effects collectively optimized the components’ heat transfer capabilities, making them several percent more efficient.

Those working on the coatings were particularly interested in developing self-healing options due to the typically limited durability caused by exposure to steam power plant settings. Extremely thin coatings can develop pinhole defects within weeks or hours of curing, and thicker options are not always viable since those can limit heat transfer.

The researchers found they could use dip coating to apply the protective layer on materials such as steel and silicon. Proper surface preparation provides the necessary adhesion between the coating and underlying material.

However, the dynamic bonds in these new coatings exhibited self-healing properties that repaired the surfaces if scratched. They also stopped existing pinhole damage from worsening. The researchers said their further work would attempt to determine why they only observed the self-healing qualities in thin layers of the coating and not large batches of the material. Answering that question could make this protective invention more marketable.

Engineer Products to Support a Renewable Energy Future

Many people agree increasing the world’s renewable energy use will decrease the need for fossil fuels and minimize emissions, among other benefits. How might self-healing paints play a role in a greener future?

A 2020 study suggested people could decrease wind-turbine-related bird fatality rates by more than 70% by painting the blades for better contrast. In 2022, government officials in The Netherlands considered a proposal to require that option. However, one of the associated downsides is black blades would absorb more heat, exposing them to more wear and tear over time. 

Thermal spray coatings protect wind turbines against high-temperature oxidation, wear, and corrosion. If manufacturers produced self-healing paints that offer protection from the elements and good visibility for wildlife, such products would tackle multiple needs arising from a clean energy future.

Use 3D Printing and Heat to Make a Protective Coating Work

Researchers from North Carolina State University tackled an enduring problem – applying protective coatings often requires taking assets out of service. That can be a major undertaking for something as large as a wind turbine blade, but it’s necessary since some self-healing coatings require oven heat to begin the repair process.

Additionally, the team pointed out that many previously developed self-healing coatings became less effective over time and successful repairs may only occur a few times. Such a limited repair window is not ideal for coated assets that people may use outdoors for several years.

Addressing these problems required using a 3D printer to apply a patterned thermoplastic heating agent onto the surface. This coating also included layers that heat up in response to an electrical current, causing them to warm the healing coating and spread into cracks or other damages. Experiments showed this approach could work at least 100 times because researchers have yet to find the upper limit. Additionally, the coating – made from readily available materials – can increase a surface’s fracture resistance by up to 500%.

Design Coatings to Match the Typical Environment

Any protective layers added to renewable energy assets must withstand the area’s climate. Sometimes, that might mean giving self-healing paint or coatings extra moisture resistance or making them able to tolerate high heat and humidity.

A group from the Indian Institute of Technology knew the solar panels in their area must withstand hot, humid conditions, so they created a polymeric coating that can handle such environments. This innovation could prevent system failures and crack propagation caused by panel damage. Tests also indicated the coating fixes imperfections in five minutes, making it ideal for managing issues quickly.

Decision-makers will be more likely to adopt solar panels and other renewable energy options if they know those possibilities are long-lasting and reliable. Progress like the coatings mentioned here proves there are many exciting options to explore, including those addressing persistent challenges. 

Think of Potential Use Cases

Determining the best ways to use self-healing paints and coatings requires those involved to think of the most likely applications and how to make those as appealing as possible.

Designing Coated Fabric to Have Multiple User-Friendly Features

One team envisioned using a metallic coating for textiles in the health care industry and kept that option in mind when designing its characteristics. For example, in addition to providing self-repairing and conductive capabilities, the coated fabric became antibacterial, and could even measure electrical signals from a wearer’s heart.

Tests showed the coating caused new conductive paths to form once someone cut the fabric, which made their coated fabric ideal for applications such as electrodes. They also verified that the antibacterial nature of the material prevented it from becoming contaminated through long-term wear or exposure to sick people.

Making Scratches Heal Through Sun Exposure

When researchers designed a self-healing coating for cars, they chose several essential characteristics. The applied layer must be durable, color-free and transparent, keeping the vehicle’s original hue visible. They created an option that fulfills all those needs. The self-healing properties activate at wavelengths of 1,000 to 1,100 nanometers – or the near-infrared light from the sun.

More specifically, when sunlight hits the damaged material, it causes the surface temperature to rise during a conversion of light energy to thermal energy. Any scratched material fixes itself as the chemical bonds in the coating’s polymers repeatedly separate and recombine. The innovation also included photothermal dyes that blend well with commercially available vehicle paints.

When the team tested this protection method in the lab, they applied it to a laboratory-scale vehicle with a spray-coating machine. Scratches disappeared after about a half hour of exposure to the mid-day sun.

A Bright Future for Self-Healing Paints and Coatings

Many of today’s products must withstand near-constant use or exposure to the weather. Self-healing paints and coatings are still a relatively niche area of study, but it’s easy to see the widespread appeal. The examples here highlight the abundant practical applications to explore, especially when you and your team consider your ultimate goals.