Researchers from the Korea research Institute of Chemical Technology (KRICT) have developed a transparent protective coating for automotive that can self-heal in 30 minutes under sunlight.
When it comes to automotive coatings, durability and the color creates the major challenge. Generally, materials with free molecular movement have higher self-healing efficiency. However, they have low durability while the material with high hardness and higher durability has poor self-healing performance.
The team of researchers has developed a transparent coating material that overcomes all these challenges. The material they developed can heal with the near-infrared (NIR) light in sunlight in the wavelength range of 1000 to 1100nm.
The self-healing protective material can heal the scratches in just 30 minutes under sunlight. To demonstrate the same, the team coated the car using a spray-coating machine. Then, they exposed it to midday sunlight for about 30 minutes. They scratch on the surface of the coating material healed under sunlight.
The temperature of the material increases as the light energy gets converted to thermal energy due to light absorption. This heat generated due to conversion, enables self-healing by dissociation and recombination of chemical bonds in the polymer structure.
The researchers created a self-healing clearcoat with a reversible polymer network based on acrylic polyol and dynamic hindered urea bonds. Then, they introduced N-butyl-substituted diammonium borate dye. The researchers combined the dynamic chemical bond with the transparent photothermal dye to induce dynamic chemical bonding when exposed to sunlight.
The transparent organic photothermal dye can absorb NIR and they do not affect the color of the product. They can easily blend with paints irrespective of the photothermal property.
The self-healing material the team has developed can be used for transportation applications and also on electronic devices. It can also be used on building materials as they are not that expensive. Also, it is expected to reduce the usage of harmful organic solvents generated from repainting the vehicles.
