A Non-Toxic Paint for Ships That Will Reduce Pollution in the Ocean

Introduction
Recent scientific research has focused on the impact of microplastics in the environment.
This is especially true when it comes to the marine environment. Microplastics are produced from
the fragmentation of plastic debris and large plastic products. With the continued reliance on
plastics, small plastic particles are finding themselves in water bodies at an alarming rate (Song et
al., 2014). Other common sources of waste and pollution in the marine environment are tiny
fragments of paint and fiberglass. According to Stokstad (2014), even though water bodies,
especially seas, might look clean, their surfaces are characterized by tiny fiberglass fragments and
paint. The hulls and decks of boats generate these microscopic fragments. Research shows that
they are hazardous to marine animals, including zooplankton, small but critical components of the
marine food web. The paint particles found in water are made up of resin or polymer, which are
organically made from plants but have similarities to plastics, and in these paint particles they
contain one or more additives, making them very similar in composition to microplastics (Turner,
2021). Despite their apparent similarities, however, paint particles have always been ignored when
discussions about micro-debris emerge. With this in mind, this paper presents an eco-friendly paint
alternative that can be used on marine vessels as an option to what is being used now and what has
previously been proposed but failed to deliver the desired outcome.

Impact of Paint Particles on the Marine Ecosystem
Paint has been a significant threat to the wellbeing of the marine environment. This is
because paint particles hold a more considerable fraction of additives than plastics and, as a result,
have a higher degree of brittleness, density, angularity, heterogeneity, and opaqueness, and are
layered than microplastics of a similar size (Turner, 2021). Paint particles emanate from both land-
based and sea-based sources. Land-based sources include degrading and disturbed coatings on
buildings and roads, which are then carried into water bodies with other microplastics through the
atmosphere, water treatment facilities, and urban runoff. However, the greatest threat of paint
particles comes from direct disturbance, weathering, and erosion of paint coatings found on coastal
structures and water vessels (Turner, 2021). The level of paint particle dumping in the water bodies
remains a matter of debate since their statistics and estimates have not been consistent. However,
rough estimations of paint particles in the total synthetic micro-debris input are thought to be a
worrying 35%. These estimates align with available quantitative data on the relative abundance of
paint particles amongst synthetic material collected by sea surface trawls as well as that found
inside the bodies of marine animals (Turner, 2021). The most worrying thing for marine
environmentalists is the significant level of chemical toxicity that characterizes paint particles
compared to microplastics and other synthetic debris of similar dimensions.
The impact of paint particles in water bodies will have comparable impacts on the
ecosystem to that of microplastics. However, paint particles have more potent additives. For
example, cadmium compounds, specific phthalate esters, and brominated flame retardants are
usually used in certain paint types (Turner, 2021). There is also the concern of lead-based
compounds employed in many paints used in various applications such as shipping and buildings.
There are also biocidal additives, which are additives that are meant to destroy or harm harmful
organisms, that are key components in marine antifouling formulations. A popular antifouling
formulation can otherwise be known as Antifouling paint which is used to protect the boat or
vessel hull from organisms that attach to these parts, causing harm to the boat or vessel. Metal
compounds found in paints in general serve several purposes, including dying catalysts, opacity
and protection, metal corrosion inhibitors, and pigment of color. While stricter laws have restricted
the application of paints with lead compounds in many sectors, the same cannot be said in legacy
coatings, which are still a significant source of pollutants in the environment. Copper is another
harmful metal found in antifouling paints. Other metal-based biocides contain arsenic, mercury,
and tributyltin compounds (Turner, 2021). These metals are not only toxic to marine but are also
hazardous to human beings.

Engineering Innovations That Have Not Worked Previously
Several solutions have been suggested and tried as alternatives for these toxic paints. One
of the alternatives is the use of self-polishing antifouling paints. When this solution was first
introduced, it was met with jubilation and termed as a significant scientific success (Jones, 2009).
However, continued use of these paints containing organotin derivatives has revealed that it has a
harmful impact on the marine environment. Another tried alternative is fluorinated polymer
coatings (Lewis, 2009). This solution was primed on the development of non-toxic and nonbiocidal coating systems that have surface characteristics that curb the secure adhesion and
attachment of fouling organisms. These coatings are also known as fouling release or minimally
adhesive layers. These coatings aim to construct surface features that eliminate the adhesive
strength of attaching organisms. As a result, the microorganisms detach under their own weight as
they grow or are removed by water movement (Lewis, 2009). The application of this idea was
championed for its simplicity.
The fouling release coatings are based on one primary class of polymers known as low
surface energy polymers. The surfaces of these polymers are free of groups which at oceanic ionic
strengths are either positively or negatively charged (Lewis, 2009). When the idea of fouling
release coatings was first explored, the focus was mainly on fluorinated coatings, but the interest
soon waned, and silicone polymers became the primary focus. With time, modifications have been
made to silicone-based fouling release coatings with fluorinated oils in place of silicone oils.
However, the goal has remained the same: to create an effective fouling release fluorinated coating
that discourages the bonding of marine organisms from the initial stages of its application. To
achieve this, scientists relied on Polytetrafluorethylene (PTFE) due to its low surface energy.
However, its continued use has proven to be a challenge. After all, it is much harder to process
because its chemical properties do not allow it to be easily dissolved, wetted, or softened using
commercial solvent (Lewis, 2009). It got worse with the realization that even chemicals that
produce the best marine coatings are ineffective when combined with PTFE.

The Proposed Solution
The proposed solution is a non-toxic paint for marine vessels that will eliminate the
generation of toxic paint particles into the water. The paint is a hybrid silicone-based antifouling
coating combined with nanocomposite hydrogel in order to equip it with durable antifouling
properties (Tian et al., 2019). The development process will involve adding nanocomposite (NC)
hydrogels into a commercialized silicone elastomer. NC hydrogels are known for having solid
antifouling characteristics because it possesses nanoparticles such as silver nanoparticles
(AgNP’s), which on their own have good antifouling behavior. Therefore, combining silicone and
NC hydrogel holds the significant potential of enhancing antifouling since it combines multiple
antifouling properties of the hydrophilic hydrogel, fouling release coatings (FRC), and functional
nanoparticles (Tian et al., 2019). This reduces slime and algae fouling, and the silicone foundation
maintains self-cleaning features, which include drag reduction and release mechanisms.
To create the new antifouling paint, the NC hydrogels will be mixed with a silicone matrix,
resulting in a new antifouling hybrid coating. The new antifouling hybrid coating will offer several
benefits, including the AgNPs will act as crosslinkers to enhance the compatibility of the hydrogel
and organo-silicone polymer polydimethylsiloxane (PDMS) elastomer matrix, it will allow the
combination of different antifouling mechanisms in order to strengthen the antifouling features of
the hybrid coatings synergistically, and lower the adhesion characteristics of fouling organisms on
the coating surface thanks to the mosaics of hydrophobic and hydrophilic domains of the coating.
In addition to all these advantages, the layer will be environmentally friendly.
Technical Description
Materials

• Glycidyl methacrylate (GMA)
• Trimethylamine (TEA)
• Hydroxyl polydimethylsiloxane (PDMS-OH)
• Trifluromethanesulfonic acid silver salt (AgOTf)
• Thioacetic acid (TA)
• Photoinitiator benzoin dimethyl ether (DMPA)
• Methyl triacetysilane (MTAS)
• N-isopropyl acrylamide (NIPAM)
• Cost
• Thioacetic acid (TA) – USD 190 per Kg
• N-iso-propyl acrylamide (NIPAM) – USD 470 per kg
• Methyl triacetylsilane (MTAS) – USD 110 per Litre
• Photoinitiator benzoin dimethyl ether (DMPA) – USD 500 per Kg
• Glycidyl methacrylate (GMA) – USD 50 per kg
• Trimethylamine (TEA) – USD 4 per kg
• Trifluromethanesulfonic acid silver salt (AgOTf) – USD 25 per g
• Hydroxyl polydimethylsiloxane (PDMS-OH) – USD 21 per kg

Fabrication Process and Time
One hundred grams of PDMS-OH and ten grams of MTAS were mixed and stirred for half
an hour as the first step of preparing pure silicone coating. The mixture was then painted on
pretreated epoxy boards. To prepare the hybrid coatings, hydrophilic polymer and trifluoromethane
sulfonic acid silver salt were mixed with PDMS-OH and mixed vigorously for 30 minutes. MTAS
was then added into the new mixture and stirred continuously for half an hour. The prepared
mixture was painted on the pretreated epoxy boards, and the mixture was subjected to room
temperatures for 12 hours for it to dry. The next step was to dry the mixture through UV lamp
radiation for 4 hours to produce the AgNP’s. During testing, the hybrid coatings demonstrated
sound antimicrobial performance for anti-algae performance and Escherichia coli. The inclusion of
hydrophilic hydrogel significantly enhanced the antifouling property as well as the elimination rate
of phaeodactylum tricornutum. As a result, the hybrid silicone-based antifouling coating promises
to be a good solution in marine antifouling and interfaces of biomaterials.
Conclusion
In conclusion the growing issue that is pollution in our oceans continues to worsen day by
day, as microplastics and toxic paint harm the marine life. The current solutions that are available
are not only ineffective but fail to solve the issue due to them still being somewhat toxic. As
discussed, our proposed solution is not only effective at being non-toxic for marine life, but
extremely durable as paint for a ship due to the added anti-fouling properties. The longer we wait
to implement a paint that is this effective, the closer we bring ourselves from the point of no return.

References
Jones, G. (2009). The battle against marine biofouling: A historical review. Advances in
Marine Antifouling Coatings and Technologies, 19-45.
https://doi.org/10.1533/9781845696313.1.19
Lewis, J. (2009). Non-silicone biocide-free antifouling solutions. Advances in Marine
Antifouling Coatings and Technologies, 709-724.
https://doi.org/10.1533/9781845696313.4.709
Song, Y. K., Hong, S. H., Jang, M., Kang, J., Kwon, O. Y., Han, G. M., & Shim, W. J. (2014).
Large accumulation of micro-sized synthetic polymer particles in the sea surface
Microlayer. Environmental Science & Technology, 48(16), 9014-9021.
https://doi.org/10.1021/es501757s
Stokstad, E. (2014). Sea polluted by paint dust. Science.
https://www.science.org/content/article/sea-polluted-paint-dust
Tian, S., Jiang, D., Pu, J., Sun, X., Li, Z., Wu, B., Zheng, W., Liu, W., & Liu, Z. (2019). A
new hybrid silicone-based antifouling coating with nanocomposite hydrogel for durable
antifouling properties. Chemical Engineering Journal, 370, 1-9.
https://doi.org/10.1016/j.cej.2019.03.185
Turner, A. (2021). Paint particles in the marine environment: An overlooked component of
microplastics. Water Research X, 12, 100110.
https://doi.org/10.1016/j.wroa.2021.100110

Reflection
Even though it was challenging to identify which topic to work on, it was interesting to find
a suitable topic and a viable solution to the chosen problem. After identifying the appropriate topic,
I found it fun searching and going through scientific literature related to marine and marine
science. I was fascinated by the fact that a lot of information is available related to this field which
shows that scientists and scholars are working hard to educate and help solve the environmental
problems that the planet is facing today.
In the process of conducting the research related to this assignment, I learned about related
to the environment and environmental pollution that I was not aware of previously. For example, I
did not know that paints are significant pollutants of the environment. From the research, it is clear
that the paint particles affect the marine environment and adversely affect the soil due to the toxic
nature of the chemicals used to manufacture paints. At the same time, I found out that the marine
ecosystem continues to suffer due to the continued usage of toxic paints on water vessels and
buildings near coastal waters. Furthermore, it is sad to see that in addition to micro-plastics, the
guts of fish now also carry paint particles in them.
However, the most striking thing for me was that despite scientific research showing that
paint particles harm the marine environment, very little has been done by the government and
policymakers to reverse the problem. Antifouling coatings containing harmful metal-based
compounds such as lead and copper continue to be used with little regulation. Further, minimal
incentive has been made to encourage research on the development of new, more eco-friendly
coatings. Nonetheless, I feel that environmentalists and chemical scientists are doing an excellent
job of introducing new viable solutions. The proposed solution by our group serves the same
purpose by promising a durable antifouling coating that is free of toxic chemicals.

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