Gentoo™
Gentoo is an advanced protective coating that offers durability and chemical resistance. It is easy to apply and clean, and can withstand even the toughest environments. With its exceptional wear resistance, high performance, low sliding angle, and flexibility, Gentoo outperforms other coatings.
Gentoo is a transparent coating that repels not only water and oils, but also acids and bases. This makes it a great choice for protecting against corrosion, enhancing wear resistance, and creating an effective barrier against chemical damage.
What is Gentoo?
Galvanic corrosion, also known as "different metal corrosion," occurs when different materials come into contact underwater. This causes one metal to corrode faster as the anode, while the other corrodes more slowly as the cathode, even if both metals wouldn't corrode on their own. It is a common and highly destructive form of corrosion.
To combat corrosion, including galvanic corrosion, NanoTech Solutions Norway has developed a sol-gel technology called Gentoo. Gentoo is a durable, transparent, and hydrophobic coating that acts as a thin repellent and barrier. It provides corrosion protection by creating a dense barrier and repelling water from the coating's surface. Despite its thinness (4-6 microns on average), Gentoo is extremely hard, flexible, and offers exceptional protection.
The hydrophobic surface treatment is a transparent coating made of a hybrid organic-inorganic matrix that uses silane-modified polymer chemistry. This treatment combines the benefits of organic polymer coatings, such as flexibility, impact resistance, durability, abrasion resistance, corrosion protection, and UV resistance, with a low surface energy to enhance hydrophobicity.
This ultra-thin coating system, with a thickness of less than 5 μm, can be applied to various surfaces including painted, untreated metallic, and polymer surfaces. It can be applied using common techniques such as flow coating, brush, or spray. Despite being transparent, the hydrophobic treatment does not alter the appearance of the surface it is applied to. Instead, it enhances water repellency, improves corrosion resistance, withstands mechanical wear and impact damage, reduces salt accumulation, and resists weathering over time.
Preparation of coatings and data
Gentoo is a straightforward, transparent coating system that has self-orienting fluorine groups on its surface. These fluorine groups are securely bonded into the coating and offer long-lasting water-repellent properties. The good news is that the low concentration of fluorine groups needed for this hydrophobic effect does not affect the adhesion to the surface.
The hybrid nature of Gentoo also includes silane functionalities, which allow for strong bonding between the coating and the surface substrate. This results in excellent adhesion to metallic, treated, and painted surfaces. The organic component of Gentoo adds flexibility and durability to the coating system. All these features work together to create a highly durable coating with outstanding water-repellent properties and abrasion resistance. You can find more details about the key attributes of this hydrophobic coating system in Table 1.
Table 1
Key features of Gentoo
Hydrophobicity and runoff
Corrosion protection
Flexibility and durability
Thickness and weight
Adhesion
Environmental durability
> 110 ° contact angle and <5 ° runoff angle.
Excellent water repellent properties. Reduces corrosion and extends the life of metal components.
Shows excellent flexibility via a tough cross-linked polymer matrix and durability.
The surface treatment is extremely thin (1-5 μm) and light.
Robust adhesion to metallic (aluminium, steel, etc.) substrates, glass, polymer (acrylic, polycarbonate) and paints (polyurethane, latex, acrylic).
Excellent resistance to degradation due to salt spray and UV exposure.
Application
Apply in a single coat using spray, flow or brush methods with minimal surface preparation.
Material properties
Stability for storage
Hydrophobicity
Flexibility
Heat resistance
Stripping stability
Wear and tear
Adhesion
Wet tape paint (adhesion)
FOD or tile resistance
Weather resistance
Water resistance
Chemical resistance
Test method
ASTM D1200
MIL-PRF-32239, 85285;
Measurement
ASTM
ASTM D2244, D522,
MIL-PRF-32239
MIL-PRF-32239 med
Cee Bee A-235
ASTM D1044, D2486
ASTM D3359
ASTM G154 Cycle 2 QUV-B,
D4329
MIL-PRF-23377K
MIL-PRF-32239,
fuel JP-8
Claim
Minimum 4 hours
6-12 months, 1.67 - 46.1°C;
37.8, 25, 4.4°C @ 3 months. ea.
Contact angle 105 + 3°;
Drainage 10 + 2°
No cracks
ΔE <1.0, no cracks after
1 h at 121.2°C
Removal
5B at 6H hardened or
mechanically ground and complete
hardened paint
Identical or better than
control
1000 hours with Dgloss <20,
DE <1.0
No effect
No / minimal effect,
better than control
Result
PASSPORT; 6 hours at 23.9 ° C
PASS; 12 months
PASS
PASS; 1/4 "mandrel; cracks
on 1/8 "with paint, but no cracks on Gentoo
PASS; No change CA / WS, gloss or DE
PASS; Cee Bee A-235 stripper
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Δ Transparency <5%
Δ Dis <3%
(per 150 cycles)
HSS Common Test Protocol,
ASTM D3359
5B at RT, 49 ° C at 96 hours
and 65 ° C at 168 hours
ASTM D3170,
corrosion evaluation TBD
Pot life (after mixing)
Gentoo properties
Shelf life
Physical properties
Fluid resistance
In connection with these tables, Gentoo has been applied by flow, spray or dip method on the following substrates; Glass, polycarbonate, acrylic, silicone, Nitronic® 50 stainless steel, aluminum alloys, anodized 7075-T6 aluminum, Alodine® and 316 stainless steel.
Treated substrates were air-cured at room temperature (~20°C) or cured at 90°C for 15-60 minutes, depending on application requirements. Coating thickness was measured at 4-6 μm depending on the substrate and application method. Three samples were used for each test and the results were the average of the tests.
Hydrophobicity and transparency
Gentoo's hydrophobic properties and light transmission properties when applied to glass substrates, are shown in Table 2. The treatment shows contact angles of > 110° and an average runoff angle of ~ 3-11 °, depending on water droplet size. Gentoo does not affect the transparency of the substrate, and shows negligible haze and maintains 100% clarity.
Table 2
Hydrophobicity and transparency of coatings
Contact angle
Runoff angle (120 μL drop)
50°
40°
30°
93.9%
112°
6 °
3 °
94.1%
Runoff angle (50 μL droplet)
Transparency (%)
Glass substrate
Glass substrate with Gentoo
Test method
Chemical resistance
Gentoo was also rated for liquid resistance when applied on MIL-PRF-23377 epoxy primer with MIL-PRF-85285D gray urethane lacquer, LHE Zn-Ni coated 4130 steel panels according to MIL-PRF-85285D liquid immersion testing and High-strength Steel Joint Test Protocol. For MIL-PRF-85285D liquid penetration testing, coated panels are cured, stored in a desiccator for at least 16 hours, and weighed before immersion in the following solvents for 7 days at 37.8°C: Flight-de-icing / Anti-icing liquid (SAE AMS 1424 ), cleaning agent (degreaser), aerospace equipment (MIL-PRF-87937) and paint remover, PR-3500 epoxy paint remover.
Glass substrate
121 ± 3°C (250 ± 5°F)
66 ± 3°C (150 ± 5°F)
Room temperature
24 hours
24 hours
7 days
Table 3
MIL-PRF-85285D - Test fluids and conditions
Lubricating oil (in accordance with
MIL-L-23699)
Hydraulic fluid (in accordance with
MIL-PRF-83282)
JP-8 fuel (in accordance with
MIL-DTL-5624
Liquid temperature
Immersion fluid
Time of immersion
Gentoo showed no blistering or coating failure and maintained hydrophobic performance after immersion in anti-icing fluid, cleaning agent (degreaser), lubricating oil, hydraulic fluid and JP-8 fuel.
Gentoo was removed using PR-3500 epoxy paint remover, as planned. Commercially available superhydrophobic coatings were also evaluated, and those coatings lost all superhydrophobic and hydrophobic performance after immersion in all liquids, and were completely removed when immersed in most liquids, with the exception of anti-icing fluids.
More information about Gentoo
Gentoo provides significant extra compared to other competing coatings with a hydrophobic effect. Especially when evaluated with standardized accelerated corrosion test methods and chemical resistance. Download the reports using the links below (eng).