Smart Coatings: Current Trends
Smart coatings are films or layers consisting of coating materials with pre-defined qualities that exhibit specific features when exposed to external stimuli such as light, pressure, or electric current. Smart coatings include self-dimming, anticorrosion, self-cleaning, biomedical, self-healing, and other coatings. In the automobile, construction, consumer electronics, and other industries, smart coatings are used on a daily basis. Despite the fact that many smart coatings are now ineffective, a great number of new ones are being developed that have the potential to have a substantial impact on both the industrial and consumer sectors.
Using Smart Coatings vs. Traditional Coatings
Many people are interested in the creation of coating systems that respond intelligently to environmental cues. In terms of advanced coatings technology, these coatings represent the pinnacle. There is a lack of sophistication in many classic coating materials like architectural house paints. These compounds are designed to protect substrates and/or provide aesthetic qualities like color, gloss, and texture to the finished product.
Functional coatings and equipment coatings are the terms used to describe coatings that are designed for specific purposes, such as corrosion resistance, fire retardance, bacteria resistance and the like. The corrosion inhibitors in coatings, for example, are often soluble and can be leached from the coating film over time, slowing the corrosion process. Corrosion inhibitors are released in this situation regardless of the likelihood of corrosion.
Types of Smart Coatings
Because of the risk of healthcare-acquired infections (HAIs) and antibiotic-resistant bacterial exposure, antimicrobial coatings have always been a popular target application. COVID-19’s arrival has sparked a surge in interest in, and demand for, self-sanitizing surfaces in settings other than medical and food processing. Significant progress has been made in recent years, and the cost associated with them is now more widely accepted.
Scratching and abrasion damage can occur on any surface, including coatings, as a result of normal use. This has a negative impact on not only appearance but also other performance criteria, such as providing a barrier. Self-healing coatings are better at preventing corrosion, thus they’re more suitable for surfaces that need corrosion or barrier protection. Self-repairing coatings can be applied in a variety of ways. One method is to use micro or nano capsules holding liquid polymerizable ingredients that are discharged into the scratch when it is damaged.
Self-cleaning and ice phobic coatings
Vehicle sensing and the necessity for clean lens and cover covers for cameras, radar and eventually LiDAR used in autonomous vehicles are driving a new use. For optimal functioning, in-car driver state sensing (DSS) devices require clean and undamaged surfaces. Camouflage and road-damage resistance are often required for vehicle exteriors. Finally, a vehicle’s performance might be harmed by an accumulation of dirt, water, and ice. Space and renewable energy sources like solar panels and windmills are other possible markets.
As capacitive switches are increasingly being used in displays and as a substitute for traditional buttons and knobs, applications such as anti-fingerprinting are seeing a surge in demand. The optical distortion is a problem with displays. The problem with high-gloss surfaces is that fingerprints are really noticeable. There are a variety of ways to do this. Due to its oleophobic and superhydrophobic properties, fingerprints can be readily wiped from the surface. If the functionality is particularly oleophobic and hydrophobic, transfer might theoretically be inhibited.
Passive thermal management
Solar and heat management Both the aircraft and construction sectors use coatings in a variety of ways. Infrared radiation from the sun accounts for 40% of the sun’s energy, which can lead to large temperature rises in warmer locations. Passive thermal management now has a new use for smart materials. Temperature control is critical for any product that will be exposed to the elements outside, including cars and planes. Batteries in devices can be extended, satellites are protected and cars are protected at extremely high and low temperatures.
Drawbacks of Smart Coatings
When it comes to smart coatings, adoption is dependent on the cost of the solution compared to the cost or performance advantage. In addition, the risk, loss of desirable features, or the market value of the performance outcome all play a role in the decision making process.
Smart coatings have the same limitations and advantages as any other plastic decoration method. There are two main difficulties with these coatings: their cost and their longevity. The automotive and aerospace industries continue to be the most demanding because of the high costs and restrictions on weight and size. All products must meet certain standards in order to last a long period of time.
The potential for new or unexpected failure modes should be assessed in order to ensure a successful implementation. Design review by failure mode (DRBFM) should be performed in addition to normal and accelerated validation testing in order to document and reduce any potential failure modes.
Smart coatings often utilise nanoparticles made of metal or metal oxide to achieve their smart functional features. Some of the time, they use rare and pricey materials that are difficult to obtain. In addition to raising costs, this causes complications with coating formulation and safe handling.
All modern coatings have the same problem with smart coatings market. In addition to the binder and pigments, coatings also contain additives and solvents to ensure their stability and processing ability. Risk of failing to achieve current standards increases when formulations get more complicated with the addition of specialized performance additives that are more responsive. The production process must also take safety handling and agglomeration prevention into account when using nanotechnology (even dispersion).
Impact of COVID-19 Pandemic
In addition to affecting consumers and the global economy, COVID-19’s introduction is changing the antimicrobial coatings market. Antibiotic-resistant bacteria and healthcare-acquired infections (HAIs) have long been the primary motivators for the development of smart anti-microbials. “Smart coatings,” or those with the most functionality, have become more prominent as a result of Covid-19’s expansion of the market. Antiviral vendors can swiftly enter the market by rebranding or repurposing current goods. Smart antimicrobial devices have always been unpopular with consumers due to their high cost and limited shelf life. As a result of smart antimicrobials being justified by health, economic, and societal considerations, this has altered. Antimicrobial research and development is heavily focused on lowering the cost and increasing the lifespan of these drugs.