In the old days, the idea of “smart paints” was considered more in the realm of animated entertainment—things of cartoons, science fiction, and adventure movies. Coatings had the ability to morph into superheroes, attack the enemy, or make evil disappear. In 1931, Dick Tracy started the first Internet of Things (IoT) with his two-way radio wristwatch, funded by a billionaire industrialist. Movies also challenged our technological imagination. The active camouflage that made a car invisible in the 2002 James Bond movie Die Another Day is now an actual coating used by the military for blending heavy equipment into a changing hostile environment. Q would be proud!

More recently, marketing departments have identified “smart paints” as just about any coating that does more than simply decorate. The definition was expanded to paints that offered what were portrayed as incredible features. Self-cleaning, self-healing, anticorrosion, self-cooling, photoluminescent, antimicrobial, photocatalytic, anti-icing, antifingerprint, insect repellent, as well as antigraffiti paints, are all examples within the smart paint universe. Some even opine that paints that exhibited metamerism when oriented differently were smart.

Currently, there is not a universal definition for smart paints, at least not one that provides agreement on what paint characteristics are included or how to quantify the market size. For now, smart coatings mean many different things, taking on a variety of forms in multiple categories. Everyone agrees, however, that smart paints do add some level of value.

The deeper discussion centers around exactly how the extra functionalities perform when in contact with outside-the-paint conditions. My idea has always been that smart coatings should have a sort of interactive AI component, a personality, rather than just a passive utilitarian function. In any event, many formerly imaginary enhancements have become everyday products available at big box stores.

21st Century Smart Paint

Oleg Figovski, director of R&D for INRC Polymate (Israel), Green Coatings, Inc., and Nanotech Industries, Inc. (USA) has what could be the best definition for smart coatings that encompasses the changing landscape: “Over the years, smart coatings have been tacitly defined as the most functional of coatings. However, that functionality of coatings and other materials has changed, and a coating that might have been thought of as smart in the past may not be considered as such now. Over time, one generation of smart coatings becomes merely functional, and a new generation of coatings takes over in the smart market category.”

If paint is to have an “AI component,” the definition given by Professor Jamil Baghdachi at The Smart Coatings III Conference in February 2011 underscored the interactive definition of functionality. He stated, “Materials that are capable of adapting their properties dynamically to an external stimulus are called responsive, or smart. The term ‘smart coating’ refers to the concept of coatings being able to sense the environment and make an appropriate response to that stimulus.”

Of course, the basis of a responsive system is the development of the requisite technology. That first line development often originates in start-up companies that can concentrate on the molecular details without worrying too much about commercialization. Next, the technology is somehow applied to an unmet need in a novel way. If successful, the smart paint innovation will find its way into the commercial arena.

There are quite a few new smart-coating applications that satisfy this responsiveness criterion. In many instances, the “active ingredient” is a specialized additive that communicates with a particular environmental stimulus to provide a solution. This article covers four smart paints that are activated by very different technologies.

Seeing Eye Paint

One example began in 2016 at the Ohio State University’s MetroLab in conjunction with the Ohio State School for the Blind. The World Health Organization estimates that there are 235 million people worldwide who are blind or severely visually impaired—a number that is expected to grow to an estimated 705 million by 2050. For people who are visually impaired, navigating crosswalks at intersections is very difficult, with only audio walk signals, traffic noise, and tactile pavements at the end of the crosswalk for guidance.¹

Relying on step count and general directional knowledge does not provide information as to whether people are walking in a straight line. This is terribly inefficient and can be frightening to a person that is slowly losing their sight. Audio GPS doesn’t really help, either. It is designed for vehicles and cannot distinguish if someone is walking on a sidewalk or in the middle of the street. It also is unable to pinpoint a building entrance.

One problem with many available technologies is that they do not provide long-term benefits or practicality for sightless traveling mobility. However, by combining light-converting oxides with normal traffic paint, a highly sensitive excitation source, a detector package (software) at the tip of a moving white cane, and a minimal weight battery pack, a coatings-system solution is within reach. Crosswalks, sidewalk edges, and building entrances can be marked with this paint and the person interacts with the paint through communication technology at the tip of the smart white cane. These paints can be black, gray, or invisible to sighted pedestrians, only detectable by smart canes.²

There are now several acres of smart paint applied at crosswalks and sidewalks throughout the OSU campus and surrounding area to quantitatively evaluate and review the efficacy of this solution (crossing efficiency and safety factors in particular). This system can also be integrated into a smart-city operating system that will interact with autonomous vehicles and other mobility systems.

One of the considerations for effective implementation is cost. Right now, smart traffic paint is about 20% more expensive than standard road paint, making it an economical option in the short term. However, volume has a tendency to reduce costs, so additional uses for this smart paint are being developed. Nothing natural converts light in the same way as the patented light-converting oxide additives and the prospects for expanded application into road and sidewalk paint worldwide makes the development of these systems economic opportunities as well.

For example, the state of Delaware and the city of Tampa, FL, are also testing this smart paint. The Ohio State University Airport has repainted selected runway markings to test the system’s ability to prevent operations vehicles from crossing runways. It is now being tested on runways to alert pilots when they are going the wrong way and as plane hold bars to augment tower instructions.

The service life testing underway in Ohio, Delaware, and Florida will help to verify the long-term durability as compared to normal traffic paint. In addition, the long-term viability of the smart paint’s ability to communicate with smart white canes will be analyzed, including performance when exposed to sunlight, snowplows, road salt, and street sweepers.

The vision for the future is that the coating will be used as easily as other traffic paint throughout the world. This is a proving to be a very economical alternative to the expensive technologies used on streets and sidewalks in Europe and Japan. The hope is that the comparatively low cost will generate a grass-roots effort for all state DOTs to embrace this smart paint.

Spray-On Antennas

From a simple Fitbit to Alexa to smart homes to monitoring and controlling operations of citywide infrastructure, the main theme of the IoT is communication. Thousands of shape-shifting and flexible “things” do not need to be connected to a public internet. Instead, they only need to be connected to a network that each gadget addresses (communicates with) individually using radio frequency (RF) antennas.

Gold, silver, copper, and aluminum work, but they are too bulky and rigid. Decades of arduous work into making improved metal antennas failed because fabrication methods can’t make them thin enough or morphable enough for any surface. Nanomaterials such as graphene (which was the subject of the Nobel Prize in 2010), carbon nanotubes and conductive polymers were promising, but required many processing steps and additives to achieve even marginal RF performance.

Constructing antennas that are small, light, and thin enough has been an elusive goal since the phrase “Internet of Things” was coined by Kevin Ashton in 1999. Enter Drexel University’s MXene antenna spray paint. This 2011 breakthrough would make installing an antenna as easy as “applying some bug spray.” Two-dimensional MXene titanium carbide can be dissolved in water to create an ink or paint. Exceptional conductivity allows the material to transmit and direct radio waves, even at molecularly thin films.

MXene, a two-dimensional titanium carbide material is stronger than metals, metallically conductive, and self-assembles into conductive films when deposited onto any surface. They are considered to be the thinnest possible water-soluble metal sheets or conductive clay. Yet hydrophilic properties can enhance the strength and conductivity of polymers AND be made into water-based paints or dyes.³ Transmission quality that can be sprayed into thicknesses of tens of nanometers to 8 microns enables antennas to be embedded seamlessly into a wide variety of objects without the complexities of additional weight, rigidity, or complex circuitry is surprisingly excellent.

MXenes are a two-dimensional ceramic family made from a bulk crystal called MAX. MAX phases are polycrystalline nanolaminates of ternary carbides and nitrides named for the general formula of Mn+1AXn, where M is a transition metal, A is an A group (mostly IIIA and IVA) element, and X is C and/or N and n=1 to 3. This material class could theoretically consist of any number of possible arrangements of transition metals. To date, about 50 MXenes with various combinations of metal, carbon, nitrogen atoms, and surface functional groups such as oxygen or halogens have been verified. And this material was not predicted to even exist before it was discovered.⁴

MXenes are fascinating because they are made of millions of arrangements of transition metals, carbon, and nitrogen. The treasure hunt is finding the ones that are stable. From results of high throughput computing platforms scanning through the formation energies of gazillions of alloying configurations, it is estimated that there are theoretically more than a million stable MXene compounds to be discovered. The ones already verified have found applications in energy storage, medicine optics, catalysis, and mechanical engineering.

Since MXenes are derived from MAX phases, the composition of the MAX phase will ultimately affect the resulting MXene. Generally, MXenes have carbon or nitrogen atoms sandwiched between the metal carbide and nitride layers (Figure 1). MXenes can be used as building blocks or combined with other 2D sheets for building any type of structure with desired and/or computer-programed properties.

FIGURE 1. Typical structures of MXenes, where red spheres show metal atoms and small black spheres show carbon atoms.⁵

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Unlike most 2D ceramics, MXenes have inherently good conductivity and excellent volumetric capacitance because they are molecular sheets made from carbides and nitrides of transition metals like titanium. As-deposited titanium carbide MXene films have exhibited electrical conductivities of 5,000 to 10,000 S/cm—exceeding all other solution processed 2-D materials— making them excellent candidates for antennas. In addition, MXenes retain flexibility, strength, and conductivity in service.⁶

To date, MXene antennas have not only outperformed metal antennas, but also other available nanomaterial technologies, all while keeping the thickness as thin as 62 nanometers. Manufacturing these antennas is also unexpectedly simple. Nanomaterials usually need binders and extra sintering steps to bind the particles together. MXene antennas are made in one step by airbrush spraying the water-based MXene ink, allowing for the precise application of coatings. MXene antennas can also be printed with this ink to be 10 times thinner and lighter than copper antennas. MXene chemistry and properties allow for a wide variety of coating applications best suited for the individual antenna design (Figure 2).

FIGURE 2. MXene coating techniques are suitable for many different antennas.⁷

Further research using MXenes in wireless communication will no doubt enable fully transparent wireless communication and greatly improved wearable devices. Already a new electrode design with MXene material allows batteries to charge much faster, from hours to literally minutes. The design could make energy storage devices like batteries, viewed as the “plodding tanker truck of energy storage technology, just as fast as the speed by supercapacitors that are used to provide energy in a pinch.” The key is the microporous design shown in Figure 3 that allows ions to quickly get to redox active sites.^.8

FIGURE 3. Fast charging MXene electrode design.⁸

In 2016, U.S. and Canadian diplomats in Cuba experienced the “Havana Syndrome”—unusual debilitating illnesses caused by directed microwave radiation or pulsed radio frequency. MXene properties can also provide electromagnetic interference shielding to protect against such attacks in the future. Due to their high flexibility and high conductivity, they can even be embedded into textiles and clothing as additional protection.⁵

Since 2011, MXenes have made successful inroads into a variety of industries, yielding a great number of applications and inventions. Figure 4 illustrates some of those growing areas and trends. It is almost a shame that the graphene Nobel Prize of 2010 overshadowed such an extraordinary materials science success.

FIGURE 4A. Industries impacted by MXene-based products from 2011–2019.⁹

FIGURE 4B. Increased number of MXene-based innovations (2011–2022).¹⁰

No Air Conditioning? Use the Sun!

A smart paint using the sun to cool without any power consumption should really be called a “brilliant” paint. Cooling down through laser beams has been known for a long time. The idea is that certain materials reacting to photons that strike them on an atomic scale can release photons with a higher frequency or energy, which means that a net energy loss takes place. This causes active refrigeration of the surface, as opposed to merely dissipating energy. This is known as the anti-Stokes Fluorescence effect. In other words, the material being hit by a photon emits back a higher frequency photon, losing its own energy and cooling down.

This physics principle came to mind on a scorching hot day in a Tel Aviv apartment with a malfunctioning air-conditioning unit. Using laser beams was the typical approach. The requirement for excitation by laser and tuning to a very specific radiation wavelength is efficient, but only for the small scale, low temperature applications with monochromatic radiation. The sun is high temperature and non-monochromatic radiation. A laser source would not work for alleviating an air conditioning problem in a hot apartment.¹¹

To that end, laser beams were replaced by the sun solar spectrum and the spectral band was tailored to match the material exhibiting anti-Stokes Florescence. The paint nano-additives were�� semiconductors excited across their band gaps, rare-earth, or transition-metal doped crystals and glasses, or polyatomic molecules in any phase excited between vibration levels.¹²

The result was a high-tech, light filtering patented coating that could be applied to roofs, buildings, and other surfaces. The coating would be activated by the sun, using strong rays to cool down structures. The more the sun would shine, the cooler it would get (Figure 6).

FIGURE 6. Anti-Stokes Florescence effect for active cooling paint.¹¹

The patented anti-Stokes Fluorescence coating has two layers. The top layer filters the photons from the solar spectrum, while the bottom one transforms heat into light. Metal roofs coated with this paint reduced temperatures at least 50 °F lower than traditional white roof coatings. The only limitation is color—it is only available in pale blue at the moment.

While the coating currently costs about $200 per square meter, it can reduce energy consumption by up to 60% and last 10 to 15 years before requiring a recoat. The reduction in energy consumption could conceivably allow new buildings to eliminate some air conditioning systems. In areas where temperatures can reach around 100 °F, a 60% reduction in usage of the electric energy grid could eliminate brown-outs and reduce CO₂ emissions from powerplants. The paint is targeted for hot weather areas as there is also a cooling effect during winter—albeit reduced by 50% due to clouds, rain, and lack of sunshine.

This “brilliant” paint can be used to cool anything under the sun. There are even ideas to use the paint in outer space for satellite and space applications to cool down equipment while eliminating expensive internal isolating and venting systems. Development toward commercialization will also bring down the price as the return on investment in the energy grid is realized.

The Walls Really Do Have Ears

Full disclosure: The one smart appliance I had over the years was a refrigerator that decided its icemaker was really a cat toy and proceeded to dispense ice cubes all over the room at random intervals. My Alexa Echo is just barely tolerated, especially after it told me that it “didn’t like my attitude” when it was instructed to provide something other than what it was apparently programmed to do. So, the idea of smart walls that track movements and communicate with appliances is not my idea of comfort.

That being said, researchers at Carnegie Mellon and Disney Research have collaborated to design a conductive paint that makes any wall interactive. The idea is for walls to function like a giant captive touch pad and as an electromagnetic sensor. In electromagnetic sensing mode, the electrode can identify distinct electromagnetic signatures of electric or electronic devices, documenting their location. If a person is wearing a device emitting an electromagnetic signature, the wall can track the location, gestures, and movement of that person within a certain distance.¹³

It is a high-tech idea that can be assembled in a low-tech way. First, walls are taped into a diamond cross hatch grid (Figure 7) and two coats of nickel-bearing paint are applied to the wall. Then the tape is removed, and the electrodes are connected to a hub with WiFi, Bluetooth, or cables. Then the whole wall is coated with standard indoor latex paint to hide the electrodes and provide normal wall durability against wear and tear. The cost is currently about $215 per square foot, but if it catches on, it could be much less expensive or even available at Lowe’s or Home Depot in a couple of years.¹⁴

FIGURE 7. Steps for painting a smart interactive wall.¹⁵

�� �� �� �� �� ��

Diamond taped grid on drywall������ ��Two coats of Ni-bearing paint

�� �� �� �� �� ��

������������������ ����������������������Tape removed; grid connected������ ��Painted (latex) wall (grid hidden)

The wall, known as Wall++, could conceivably run all the smart appliances in homes without the need to attach sensor tags, charge batteries, or maybe even spend thousands of extra dollars on smart appliances that have their own computer minds.

Seriously speaking, This active wall could also be helpful to the elderly who live alone. Through communication with a wearable (such as a smart watch or armband), the wall could turn on lights, play music, read audiobooks, or call family—all functions that help eliminate isolation, enhance personal safety, and allow for better aging in place.

Interactive walls could have applications in hospitals, gyms, museums, schools, offices, airports, and factories to sense environmental conditions, display information, harvest energy, and monitor vital signs and devices. Once Disney releases this concept to the public, more interactive uses could be discovered—maybe it is even in use today at Epcot Center.

In Summary

References

1. Clevenger, C. Leading the Way with Smart Paint. Ohio State University, College of Engineering. September 20, 2018
2. Levine, Ben. Ohio State University Partners Develop Smart Paint to Help Visually Impaired Navigate Cities. Government Technology. February 5, 2018.
3. Faulstick, Britt. Drexel’s Spray-on Antennas Could be the Tech Connector of the Future. Drexel News–Science and Technology. September 21, 2018.
4. 2D Carbides and Nitrides (MXenes) A.J. Drexel Nanomaterials Institute. https://research.coe.drexel.edu/mse/nanomaterials/research-old/synthesis-of-nanomaterials/mxenes/ (accessed November 2, 2023).
5. MXene Association. MXenes are revolutionizing nanotechnology with the help of Raman Spectroscopy. April 14, 2022.
6. Oksana, G, et al. Electrical Properties of MXene Thin Films Prepared from Non-aqueous Polar Aprotic Solvents. Journal of Materials Research. Vol. 38, pp. 3227-3237. May 2023.
7. Figure 2. Fan, Xingce, et al. Flexible Two-Dimensional MXene-based Antennas. Nanoscale Horizons. Issue 3, 2023.
8. Figure 3. Drexel University. In the Fast Lane—Conductive Electrodes are Key to Fast-Charging Batteries. Nanowerks. 2017.
9. Nguyen, U.H. and B.S. Nguyen. Novel Architecture Titanium Carbide (Ti3C2Tx) MXene Cocatalysts Toward Photocatalytic Hydrogen Production: A Mini Review. Nanomaterials. 10(4). March 2020.
10. Anasori, B., and Y. Gogotsi. MXenes: trends, growth, and future directions.��Graphene and 2D mater7, 75–79 (2022).
11. NoCamels Team. The ‘Coolest’ Invention: This Israeli High-Tech Paint Cools Buildings with Sunlight. Israeli Innovation News. November 27, 2017.
12. Shenhav Y., et al. Cooling with Anti-Stokes Fluorescence. US 2019/0154316 A1, May 23, 2019
13. Matcher, E. This Conductive Paint Turns walls into Giant Touchscreens. Smithsonian Magazine. April 30, 2018.
14. Spice, Byron. Paint Job Transforms Walls Into Sensors, Interactive Surfaces. Carnegie Mellon University News. April 23, 2018.
15. Spice, Byron. Conductive Paint Transforms Walls Into Sensors, Interactive Surfaces. Carnegie Mellon University. April 2018. https://www.cmu.edu/news/stories/archives/2018/april/paint-transforms-walls-into-sensors.html (accessed October 19, 2023).

Cynthia A. Gosselin, Ph.D., is director at The ChemQuest Group, ChemQuest Technology Institute, ChemQuest Powder Coating Research. Email:��cgosselin@chemquest.com.

By Leo Procopio, Paintology Coatings Research LLC

CoatingsTech asked several industry experts for their thoughts on the traffic paint and road markings market. Topics included the current state of the market and the commercial and technical challenges facing the industry. They also remark on exciting technical developments and new products, the role of sustainability, and provide their thoughts on the potential future for the segment.

Participants in the Q&A roundtable discussion include experts in the traffic paint and road-marking industry from raw material suppliers and coatings manufacturers. The industry experts providing comments include:

• Adam Fasula—marketing manager at Kraton
• Art Leman—NA marketing manager for road markings at Dow Coating Materials
• Kevin Lowe—director of product management for thermoplastics, PPG’s Traffic Solutions business
• Dan Stark—research specialist at Arkema Coating Resins
• Maria Wang—director of product management for liquid coatings, PPG’s Traffic Solutions business
• Angela Young—market segment manager at BASF

Expert Q&A

��Q: How would you describe the current state of the traffic paint and road marking industry, and what are some key challenges facing the industry today?��

Fasula (Kraton): The road marking sector continues to thrive at the present time, expanding steadily in many parts of the world, and is looking promising for the future. I have observed a remarkable unity within the road marking industry across the entire value chain, driven by our collective mission of enhancing road safety and ultimately saving lives. However, region-specific challenges impact the road marking industry, with labor availability being a significant concern in the United States. Despite sufficient funding for road marking projects, the industry faces limitations due to a shortage of skilled contractors, potentially hindering growth opportunities. Regulatory ambiguity, notably surrounding the Build America Buy America (BABA) Act, is another major issue for the US road marking business. Currently, there are gaps in the regulations, leading states to interpret the rules differently as they strive to comply. Comprehensive guidelines are eagerly awaited by the industry, as they are expected to bring clarity and consistency, enabling smoother operations and informed decision-making.

Leman (Dow):�� The state of the traffic paint and road marking industry is very strong with support from the Infrastructure Investment and Jobs Act bill passed in 2021. Also supporting our industry is an increased focus on road safety and reducing accidents and fatalities. Some key challenges in the recent past have been material supply and labor availability. While the material supply situation seems to have eased, there continue to be challenges with having enough labor to work on all the construction and maintenance infrastructure projects.

Stark (Arkema):�� Traffic coatings are critical to the livability and safety of urban areas – and represent strong opportunities for those companies investing in the industry. The future of the industry will be driven by a variety of factors, including continued pricing pressures, regulatory actions, the emergence of autonomous vehicles and innovation in other cementitious coating applications.

Trends include cool-pavement coatings, more colors beyond yellow to accommodate bike and pedestrian traffic, and the need for more sustainable coatings. Additionally, we anticipate growth driven by the Inflation Reduction Act and the need for longer-lasting coatings.

As autonomous vehicles begin to gain traction, the sector must adapt to ensure safety in a mixed-driver environment. This change will necessitate greater uniformity in traffic markings across various types and jurisdictions—local, state, and federal. Revisions to the Manual on Uniform Traffic Control Devices (MUTCD) in 2022 included retroreflectivity minimums and spotlight life cycle assessments and cost-per-road-mile comparisons for different marking types, stressing their growing significance.

Wang (PPG): The road marking industry is poised for growth on the tailwinds of the Infrastructure Investment and Jobs Act funding, and we are excited to provide a suite of solutions in our product portfolio to meet the needs of this growing market. PPG’s Traffic Solutions business partners with our customers to help them overcome challenges such as labor shortages and regulatory issues through new products and services that can help our customers improve their productivity.

Young (BASF): One key challenge the industry faces is the difficulty in funding roadway improvement projects. While we’ve made short-term gains, our long-term investment gap continues to grow. We need to get the funds allocated to the right jobs, get the right crews, and fund projects at the right time. I believe the US Infrastructure Investment and Jobs Act (IIJA) is a step in the right direction, but we still have a long way to go in addressing our infrastructure needs. Another challenge is created by the approval process for traffic paint markings. To get a product adopted, extensive work must be done with the DOTs. For that to happen, we must ensure our products do not impact any safety concerns and we must navigate the complexity of each state DOT. While there are challenges, there remain opportunities within this space.

Q: What are some key trends and drivers of technical innovation in the traffic paint market?��

Stark (Arkema): The emerging autonomous vehicles trend is steering the need for “smarter” road markings. These enhanced markings feature increased brightness, durability, improved adhesion, and heightened retroreflectivity, enabling better visibility on the roadways.

Wang (PPG): The US DOT zero deaths vision drives the FHWA guidance on wider and brighter lines, along with other local safety initiatives such as the Safe Streets and Roads for All program. PPG’s Traffic Solutions business has a pipeline of technical innovations to enable more durable lane markings with sustained retroreflectivity, enhancing driver visibility even in adverse conditions such as rainy nights. ��Additionally, the focus on performance in recent state specifications, as opposed to composition in older specifications, drives technical innovation and reduces the complexity of product SKUs for our customers.

Young (BASF): The number one trend in traffic paint is enhancing driver safety. There is a push for paints to be more retroreflective, for products to perform in harsher weather conditions and for extending the striping season so paint can be applied in cold weather applications. There are also new technologies that support, and continue to evolve, intelligent street marking systems that can communicate with the vehicle and other sensors.

Fasula (Kraton): Two key trends driving technical innovation in road markings are the aging population and the increasing adoption of autonomous vehicles (AV) technology. Aging populations require brighter markings with improved contrast in daylight and higher reflectivity at night. Additionally, machine vision relies on sharp-edged and more prominent markings for consistent recognition. The need for brighter, sharper markings with improved contrast and reflectivity poses challenges for scientists and formulators in developing superior reflective materials, enhancing glass bead adhesion, and improving the durability and visibility of road markings.

Leman (Dow): Selection of polymer continues to be a driver of increased durability in traffic paints. For example, most pavement marking products are known by their polymer descriptions, e.g., acrylic, epoxy, thermoplastic, etc. At Dow we continue to innovate new products and have launched FASTRACK™ 5408A to the industry for increased durability and retroreflectivity as well as colder temperature applications.

Q: What new technical developments do you consider exciting for the road maintenance and traffic paint segment?

Young (BASF): With autonomous vehicles imminent, road authorities must support both the human driver of today and the machine driver of tomorrow. That requires improvement of lane markings across the country and the ability for vehicles to interact with them. Two ways to accomplish this goal are to increase line width from 4 to 6 inches and use high-quality paint in road markings.

Fasula (Kraton): One of the most exciting advancements in the road marking industry is the development of technologies for wet-night visibility. Enhanced road markings that provide visibility in rainy conditions, such as structured markings that protrude through the water film and markings that employ specialized optics for underwater reflection, have the potential to save many lives.

Leman (Dow): Recently there have been updates to the MUTCD (Manual for Uniform Traffic Control Devices) which now establishes minimum retroreflectivity standards for pavement markings. While the requirements are not considered by many to be too stringent, it is a good start for ensuring pavement markings have good visibility, retroreflectivity, and maintenance. Autonomous vehicle features in automobiles such as lane keep assist rely on detection of pavement markings to work most effectively.

Stark (Arkema): Trends such as cool pavement, multiple colors, autonomous vehicles, and sustainable product development are driving the need for new solutions in these markets. Arkema is working closely with customers, suppliers, and organizations across the industry to identify the unique challenges these trends create and help produce the best possible solutions.

Wang (PPG): The trends towards automation, whether in application equipment or connected and autonomous vehicles (CAVs), open a new world of possibilities for pavement markings. PPG’s Traffic Solutions business is excited to work with our Mobility team within Automotive OEM Coatings on innovations that improve the safety and navigation of CAVs. We are also pursuing partnerships with equipment manufacturers to co-develop new coatings and automated application/monitoring processes to help improve safety in work zones. Currently several state DOTs are testing the use of ENNIS-FLINT® by PPG orange traffic paint and hot-applied thermoplastic to increase driver awareness of work zones for their safety and that of the construction workers.

Q: Do you have any new products or technologies for road markings that you would like to highlight, and what benefits do they bring?

Leman (Dow): FASTRACK™ 5408A is a new generation of all-acrylic emulsion for fast-dry waterborne traffic marking paints with improved durability. Traffic marking paints based on FASTRACK™ 5408A Emulsion feature fast dry over a broad range of application conditions and excellent durability in terms of retention of glass beads for night visibility and wear properties over asphalt, concrete, and previously applied markings. Other benefits of FASTRACK™ 5408A include enhanced retention of glass beads for excellent long-term night visibility, environmentally friendly formulated VOCs from 50 to 100 g/L, user friendliness, and extending the striping window to include paint application temperatures down to 35°F (and rising).

DURATRACK™ R-100 and AEH-100 Resins for Green Bike Lanes: Dow’s DURATRACK™ two-component (2K) technology for broad area markings make a great point for bicyclist safety. The green bike lane coatings increase the visibility of bicyclists for drivers, safety through clearly delineated space, and motorist yielding behavior to those in the lanes, as well as discourages parking in the bike lane. ��In addition, it yields pleasant results such as superior adhesion, skid-resistance, UV durability, and quick drying time, while enhancing work-zone safety through a speedy and efficient installation process. This traffic paint technology is projected to cut costs per mile by about 80%, which will hopefully lead to more green bike lanes.

Lowe (PPG): We are actively converting existing and new customers from granular hot-applied thermoplastic to THERMODROP® pelletized thermoplastic. This innovative pelletized thermoplastic material is a premium, pre-melted, homogenous, and fully encapsulated pavement marking compound that is provided in a free-flowing pelletized form. The results are 1) increased cleanliness, color efficiency, and material consistency; 2) increased productivity from longer runs and/or more runs per day, i.e., more “guns-on time”; and 3) reduced lane interruptions.

We are gaining market momentum with our HPS®-8 Integrated Multi-Polymer solution, which is a unique binder system composed of a series of polymers designed for high abrasion and impact resistance similar to traditional high-durability systems such as MMA and epoxy. However, due to the nature of these polymers, HPS®-8 Integrated Multi-Polymer is 100% solids and can be applied by standard thermoplastic extrude equipment at thicknesses as low as 50 mils and up to 120 mils. The polymers in HPS®-8 Integrated Multi-Polymer also offer excellent adhesion. Long-term retroreflectivity is achieved through an intermix of both Type 1 and Type 3 beads. Upon cooling to normal pavement temperature, HPS®-8 Integrated Multi-Polymer provides a very durable marking material for low and high-volume traffic areas.

Stark (Arkema): In 2023, Arkema will introduce ENCOR® 5650 acrylic, a new product for concrete coatings designed to offer improved blush resistance, longer life span, and improved hot tire pickup in applications such as garage flooring.

We also offer several existing binders that provide value to formulators of traffic markings:

• ENCOR® DT 250 latex, a high-performance second-generation fast-dry latex binder designed for optimum performance.
• ENCOR® DT 100 all acrylic, a general-purpose APEO-free binder with excellent durability and sustainability attributes.
• ENCOR® DT 211 all acrylic, a fast-drying binder for traffic markings applied at standard line thickness of typically 15 mils wet.

Wang (PPG): We are launching our next-generation Extended Season MMAX® area markings this summer. This proprietary methyl methacrylate (MMA) technology offers the widest temperature application range in the market. For the first time ever, it is possible to apply MMA markings such as green bike lanes and red bus lanes on pavement surfaces as hot as 150° F, which can happen even at air temperatures of 97°F. Extended Season MMAX® area markings are available in easy-to-mix kits with catalyst and corundum – the hardest, most wear-resistant anti-skid aggregate – making MMAX® area markings eligible for top-tier skid-resistance specifications.

Young (BASF): One exciting innovation that we are in the process of launching is our ACRONAL® Xpress 4360. This product is a development of a higher performance latex for waterborne traffic paint. The primary benefit is improved drying time. We are currently going through industry standard testing including NTPEP testing to validate long-term performance in real-world use.

Fasula (Kraton): Kraton has introduced several new products for road marking applications, with SYLVABIND™ C200 and SYLVABIND™ H300 being the highlights. These offerings mark the first entries from Kraton’s Polymer Modified Resin (PMR) technology platform. Leveraging PMR technology, formulators can design thermoplastic road markings with significant benefits. SYLVABIND™ products are resin-based, incorporating pre-blended elastomers to ensure ease of use and predictability during application. They also exhibit excellent glass bead retention, contributing to long-lasting visibility. Our C200 product is specifically formulated for cold to temperate climates, delivering exceptional impact resistance to withstand the abuse of snow plowing. Our H300 product is designed for temperate to hot climates, offering improved high-temperature compression resistance, which allows structured markings to maintain their profile, ensuring durable wet-night visibility. Kraton’s commitment to innovation and delivering solutions that meet the needs of global road marking professionals is exemplified by the successful outcomes of SYLVABIND™ C200 and SYLVABIND™ H300. These materials have demonstrated excellent results in road trials conducted by our customers in the Americas, Europe, and Asia, and they are now readily available for implementation.

Q: How is the industry and/or your company dealing with the topic of sustainability in traffic paints and road markings?

Wang (PPG): PPG’s Traffic Solutions business has a sustainability strategy for new product development and lifecycle management that supports our corporate ESG targets. Besides ongoing efforts to proactively reduce chemicals of concern in our formulations, as well as increase recycled content, we also offer sustainable packaging to our customers. Traffic paints are available in reusable asset totes that we pick up, clean, and redeploy in our production facilities.

Lowe (PPG): Additionally, the majority of our thermoplastic markings use alkyd resins which are sourced from suppliers utilizing sustainable forestry management practices.

Young (BASF): Sustainability will always remain an extremely important pillar for BASF. As federal specifications and environmental regulations tighten, waterborne traffic paint will continue to be a preferred road marking. The industry is currently balancing sustainability with cost and safety, but our team will continue to support stripers with individual state requirements.

Fasula (Kraton): Acknowledging Kraton’s longstanding leadership in sustainability well before it became a popular trend is important. Since the 1910s, Kraton has been a leading supplier of pine-chemistry-based materials. Our pine-based resins have been used to replace petroleum-based resins in US and European thermoplastic road markings because of the performance advantages they bring, especially glass bead adhesion and resistance to automotive chemicals. With our sustainability expertise and innovative materials, we have successfully assisted customers in achieving their sustainability goals by minimizing their environmental footprint, reducing microplastic contamination from road markings, and maximizing durability.

Leman (Dow): One of the benefits of longer lasting waterborne traffic paints is that they can extend the amount of time needed for replacement so that maintenance applications do not need to be conducted as often. This is also beneficial when there are challenges with labor availability and participation. Also, waterborne traffic paints do not require equipment to heat the material at high temperatures, saving energy and fuel.

Stark (Arkema): As a company deeply committed to the acrylic value chain, Arkema delivers a comprehensive range of materials for waterborne acrylic traffic paints. Our offerings span from monomers for acrylic emulsion production, to acrylic emulsions, rheology modifiers, and dispersing agents for these formulations. Sustainability and safety are at the heart of everything we do. We endeavor to eliminate harmful substances like VOCs and formaldehyde from our products, while also introducing renewable content into our formulations. A key aspect of our strategy is enhancing the durability of our products, a step which contributes to lowering the overall carbon footprint of traffic paints. This holistic approach allows us to provide effective, environmentally responsible solutions to the industry.

Q: What do you consider the most difficult technical problem facing raw material suppliers and coatings manufacturers of traffic and road marking coatings?

Fasula (Kraton): Some of the most challenging and intriguing technical problems are some of the long-standing challenges, such as ensuring visibility in wet-night conditions, delivering durability in diverse climates, achieving predictable adhesion to difficult-wearing courses, and addressing glare from low-angle sun for machine vision in the context of AVs. These problems necessitate ongoing research, innovation, and collaboration to develop solutions that balance visibility, durability, adhesion, and compatibility with evolving road surfaces and environmental conditions, ultimately advancing the industry and enhancing road safety.

Stark (Arkema): As autonomous vehicles begin to share the road with human drivers in more environments, there will be a growing emphasis on safety and durable, highly-visible traffic markings will be more important than ever.

Wang (PPG): Traffic paint is expected to dry within a few minutes on the road and yet needs to remain stable in liquid form before being applied. It is a very challenging technical problem to drive film formation during application but not in storage.

Lowe (PPG): This is compounded by the complexity from an overall product portfolio perspective, for paint and other markings, as the required color performance and other specs are different for each state.

Young (BASF): A technical problem facing our team is the ability to produce a fast-drying paint while maintaining stability. It is important to have a fast-drying paint that gets crews off the road quicker, and for the road to return to normal so that cars can come back. At the same time, we need the paint to not thicken or gel prematurely. There is always a pressure to meet the demands of the industry and we continue to evolve and develop products that meet those performance requirements.

Q: If you could predict the future, what changes and/or new innovations do you foresee for the traffic paint and road marking segment in the next 10 years and beyond?

Stark (Arkema): In the coming decades, the traffic marking industry will need to focus more on a lower carbon footprint, increased durability, and safer constituents. Likewise, ongoing engagement between road marking manufacturers and autonomous vehicle makers will be crucial. This collaboration will ensure alignment between the evolving requirements of autonomous technology and the markings that guide these vehicles, fortifying safety and efficiency on our roads.

Wang (PPG): My prediction is that we will see increasing functionality of pavement markings in terms of enhanced performance and mobility-enabling technologies while improving upon ease-of-application, robustness, and sustainability attributes of the products.

Lowe (PPG): Consequently, I think we will see a shift towards implementing solutions that are more cost-effective over the expected service life of roads.

Young (BASF): 10 years and beyond is a long time considering all the innovations that have come in the last 10 years. Obviously, safety will remain the top concern for this industry. We need to continue developing paints that dry quicker to get crews off the road and remain visible for longer to heighten driver safety. In the future, having road markings interact with autonomous vehicles will become increasingly important as well as applying paint in different weather conditions whether that be early rain resistance or another need.

Fasula (Kraton): Autonomous Vehicles (AV) manufacturers and suppliers made a wise decision in designing systems that work with existing infrastructure, acknowledging the reliability and elegance of pavement markings as a guide for machine control. Human vision will continue to be essential for years to come, and while connected vehicle (CV) technology is intriguing, pavement markings remain unmatched.

With the collaboration between the Society of Automotive Engineers (SAE) and road authorities, we can anticipate the trend of wider and brighter markings to continue. The increasing adoption of wet-night visibility solutions is also expected as road authorities prioritize safety enhancements. Looking ahead, we will witness the development of new solutions to address challenges like snow visibility and other complex scenarios for AVs.

Leman (Dow): Improved durability, performance, and low temperature application continues to be a market need. However, some of the changes can come from expansion of existing best practices such as taking regular retroreflectivity measurements of markings to determine their durability and performance on various road surfaces and traffic conditions. On our own test deck and from NTPEP data we continue to see wide variation in performance of waterborne traffic paints which can be improved by the selection of more durable polymers such as FASTRACK™ 5408A.

Lane markings are the positioning rails for automated driving systems and the guard rails for advanced driver assistance systems (ADAS). Road markings are critical to enabling AV Ready Roads, and this requires continued innovation and importance on the items above (durability, retro-reflectivity, etc.) ��The industry will continue to understand the differences between human vision and machine vision, in order to optimize markings for machine vision.

Leo J. Procopio, Ph.D., is president and owner of Paintology Coatings Research LLC.�� For more information, visit www.scienceofpaint.com or e-mail at leo.procopio@scienceofpaint.com.