How Carbon Nanotubes Reduce Mechanical Damage
Carbon nanotubes (CNTs) are tubular particles comprised of a single layer of carbon atoms, which are dwarfed by the size of a human hair. Despite their nanoscopic size, CNTs- the strongest material known to man- demonstrate incredible strength when synthesized with epoxy coatings.
At Tesla NanoCoatings, we have engineered protective coatings that demonstrate all the best properties of CNTs to guard your steel assets. These protective qualities are not just complemented, but further elevated in our coatings by the addition of zinc.
Carbon Nanotubes: The Strongest Material Known to Man
On their own, CNTs possess an inherently spectacular strength. The physical bonds that hold CNTs together give it a tensile strength that is up to 50 times that of steel. This bond gives CNTs two distinct advantages.
The first advantage is its unmatched flexibility. Even after a TESLAN coating has been applied to a steel substrate and had sufficient time to dry, the bonds between nanotubes allow them to flex enough to withstand great mechanical impacts without failure.
The second advantage is the superior adhesion between TESLAN coatings and steel substrates. The high tensile strength of CNTs keeps our coatings more strongly bonded to steel than even some of the best adhesives are capable of. In pull tests, where a dolly is glued to a coating then pulled to evaluate when the coating will fail, our results consistently show the failure of some of the strongest glues before our coatings even begin to budge.
A Monolithic Bond Improves Impact Resistance
Compounding on the strength of the bonds between CNTs is the monolithic bond that they form with the surrounding epoxy. As the epoxy sets around the CNTs, they become inextricably bound with one another to produce a level of strength and impact resistance that is simply unrivaled.
TESLAN’s unique wet-on-wet application process allows a topcoat to be applied to a primer before it has dried entirely. While this makes for an especially quick coating process, an additional benefit of this process is that it allows CNTs to bond with each other between layers, further increasing the strength of the coating overall.
The Self-Aligning Carbon Nanotube Matrix
CNTs work differently. While the epoxy is still wet, they actively self-align to form a matrix with one another. This self-alignment is exactly why the monolithic bond can be formed between primer and topcoat layers, thanks to our wet-on-wet application process. In doing so, the epoxy and CNTs also form a bond with one another. The resulting matrix allows CNTs to imbue a rebar-like strength into the epoxy coating once it has dried. In the case that the finished coating does sustain damage despite its high impact resistance, the CNTs can still pass electrons around the damage site to offer cathodic protection against oxidation.
The physical properties of CNTs are key to providing strength to our TESLAN coatings. To learn more about the role that carbon nanotubes play here at Tesla Nanocoatings, read our article The Function of Carbon Nanotubes.
How CNTs and Zinc Prevent Corrosion Damage
Although carbon nanotubes are known for their incredible physical strength, that is not all they have to offer in our protective coatings. The CNT matrix combined with zinc facilitates the highest level of cathodic protection to steel. Even in the event of a mechanical coating failure, the threat of corrosion is near eliminated.
The Conductivity of Carbon Nanotubes
CNTs prove once again that they are not to be underestimated. As if outstanding tensile strength wasn’t enough, CNTs are also highly conductive. That’s putting it lightly- CNTs have one thousand times the current carrying capacity of copper, a metal widely regarded as one of the most conductive.
The way this plays into protecting steel is by providing a seemingly endless network for electron exchange to take place on. Think back to the CNT matrix of a TESLAN coating. CNTs are evenly distributed throughout the entire coating, even bonded between layers. This means that if mechanical damage to a coating poses a risk of corrosion to the exposed steel, an electron from the zinc can be donated along the CNT matrix in place of the steel’s electron, no matter the distance from the damage site. It can be a centimeter, a meter, or even 100 meters away. So long as the coating is cohesive, the CNT network can deliver an electron from one point to another in almost an instant.
The Galvanic Properties of Zinc
Those sacrificial electrons have to come from somewhere: enter zinc. Already a common additive in protective coatings, this metal displays what are known as galvanic properties.
A galvanic metal is one that will readily give up its electrons before steel will. The term galvanic protection is exactly what it sounds like: steel is protected by a galvanic substance in order to prevent corrosion. This is the principle behind galvanized steel, which is coated in a layer of zinc to prevent oxidation.
The same principle applies in TESLAN coatings. By incorporating zinc into our formula, a host of extra electrons is made available to prevent oxidation from forming on any exposed steel.
Zinc and CNTs Combine to Offer Superior Cathodic Protection
The combination of zinc and carbon nanotubes is what makes TESLAN coatings truly special. CNTs provide an expansive network throughout the coating for quick electron travel across any distance, while zinc content provides additional electrons to preferentially corrode in place of the steel. By working together, these two materials make the steel substrate underneath practically untouchable. Even in the harshest physical environments, or those that are subject to high electrochemical activity, TESLAN coatings have both the brains and the brawn to bounce back from nearly anything you can throw at them.
To learn more about the technologies that define Tesla NanoCoatings, visit our About Page. If you’re interested in utilizing our quick coatings in your offshore, marine, or midstream operations, contact us today.