Nanotechnology and Anti-fouling: Project Tideman Workboats
By Rob van Hoorn
nC Surface Technology
Anti-fouling is one of those areas in the maritime industry that is subject to constant development. Especially in areas where traditional coatings have difficulties to hold their own on the host-surface, nanotechnology is a solution that will succeed by nature, as nanoparticles tend to bond into surfaces rather than stick on them.
Tideman Boats is a Dutch constructor of indestructible workboats. Their concept, nominated for the Maritime Innovation Awards 2016, embraces the construction of single hull vessels completely made out of High Density Poly Ethylene (HDPE). HDPE is a sheer indestructible material. That means the product life cycle is much longer than any other material, like aluminium and Glass Reinforced Plastics (GRFP). Plus: the HDPE hull is completely recyclable.
Workboats operate in rough, hard environments: Rocky shores, shallow waters, arctic conditions, you name it. And here comes the challenge: HDPE is too dense for anti-fouling paints or foils to adhere good enough to withstand these conditions aforementioned. Dutch-based nC Marine had to prove that nanotechnology can do the little extra. With a Durazane based nano coating, nC Protect 4400, they ran the gauntlet.
But first: Nanotechnology. It is a word that has a bit of fantasy. Word has it that “nano can do anything.” It is often believed that this technology is out of reach. Too expensive. Complicated. Well…it improves upon acquaintance.
During the nineties and the first decade of this century, nanotechnology and especially the accompanying application techniques have grown to full maturity. This meant prices for nanoproducts dropped, and application possibilities spread wider over more types of material. Today, nanotechniques in the fields of corrosion, abrasion, thermal and electrical insulation, lubes and fuel, active cleaners and selfcleaning surfaces are available. All on the level of quality only the maritime world can ask for. Foodgrades, class approvals, EPA and IMO acceptance, OEM Letters of No Objection, it’s all there.
Nanoparticles are small. That helps a lot, as nanotech is all about spreading and building matrices inside and on the surfaces of materials. Particles entirely fill in the intermolecular spaces of for instance glass or metals. In this process, binders and activators make that a number of reactions take place, offering and adding great advantages to and over the traditional techniques like painting, lubricating or insulating.
The one most important reaction of nanoparticles is that they don’t stick mechanically, but bond chemically inside the host materials. Crucial in the case of treating HDPE with an anti-fouling. The particles become one with the material and cling covalently to themselves. This means literally nothing can enter the host material anymore, thus changing or enhancing material characteristics. Pull or breaking strength of the host material, or brittleness, will not change however.
The typical properties of the nanoparticles subsequently determine how the host material is altered. Nano-tungsten offers unseen abrasion resistance. Nano-borate is extremely low in friction. Nano titanium-oxide particles make surfaces self-cleaning. And much more types and shapes of particles can be found, the list is still growing.
This all means we now can very well protect, strengthen or enhance our host material. Still we have to transport the particles to the surface, in this case to the HDPE hull of the Tideman workboat. Here comes the so-called carrier into play, paint, water, alcohol or grease are good examples of a carrier that can transport nano-particles to a surface, without interfering with the functionality of these particles.
In the introduction we mentioned that nanotechnology was expected to be expensive and complicated. nC Protect is a technique that proves the opposite is true. Defined by USA-based Merck and fine-tuned by nC Marine in a series of high performance nanocoatings in cooperation with Dutch shipowning companies, it is applied without primer in one single coat. This affects pricing a lot, as the coating is some 40% lower in price per m² than the average prices we see for anti-fouling today.
“Easy!” was the first reaction of Bruno Tideman, CEO and developer of the indestructible workboats carrying his name, when he applied the coating for the first time on the HDPE hull, instructed by nC Marine’s CTO Rob van Hoorn. “Before we decided to test this solution, we had serious doubts if we were capable of getting the anti-fouling on the extreme quality levels that the working environment of our workboats require. Foils and traditional coatings have their downsides where tear-off rate, application, sturdyness and price is concerned. I was surprised that with only cloth and a very tiny amount of fluid, the whole solution materialized in less than an hour of work.”
The nanocoated Tideman Workboat was delivered to Brabo Boatmen, Antwerp in March 2016. Excellent chance for both boat and anti-fouling to prove their capacities. Today, after spring and a warm summer, the boat shows a sound and shiny underwater hull, with hardly any fouling or growing-on. The nanocoating proves to be shear and shock resistant, and is very easy to clean from dirt, mud or grease. This means that the HDPE will not be affected by the destroying work of barnacles, sand or chemicals, and will stay fuel-efficient, as the engine does not have to propel a bearded hull through the water. It also means that this coating, which is not based on fouling-release, but on sheer smoothness and exceptional hydrophobics, is not wearing off and will not pollute the waters. Both cost-effective and environmentally sound characteristics that are required in today’s sailing era.
Meanwhile 4 more boats have been coated with the nanocoating. We keep you informed about developments via this Industry Contribution area, as coating of HDPE and polyesters are common ground in the maritime world.
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