I-Tech Partnership Combines Antifouling Technologies
Developers of antifouling biotechnology I-Tech AB and global specialty chemicals company Lanxess recently announced that they have successfully combined their respective antifouling technologies with positive results.
According to an emailed press release, static tests of antifouling coating formulations containing Selektope and the Sea Nine family of biocides were conducted in multiple marine environments worldwide with differing biofouling risk, with results providing proof of concept.
A data pool of coating formulations has also reportedly been developed that can be used by antifouling coating manufacturers to support the trialing of new combinations of existing biocides without the need for additional research and development.
“This year the I-Tech R&D team is harvesting the results from many successful collaborative projects undertaken with fellow antifouling technology developers,” commented Dr. Markus Hoffmann, Technical Director at I-Tech.
“We believe this is the only way forward when trying to ensure that our technology helps the maritime industry to tackle increasing biofouling issues. Biocidal antifouling coatings are here to stay and at I-Tech we are invested in ensuring that the technology available now can be used to best effect in the future by proving performance across as many different potential application scenarios as possible.”
Selektope from I-Tech is an organic, non-metal biocide that prevents hard fouling. It uses an active agent, medetomidine, to repel barnacle larvae from a coated surface with a non-lethal effect.
Lanxess Sea-Nine is based on an active substance DCOIT, which reportedly has a broad anti-microbial activity spectrum with a special emphasis on soft fouling prevention. Sea-Nine 211N contains 3-% DCOIT, while Sea-Nine Ultra contains 80% DCOIT in a rigid core-shell encapsulation format.
I-Tech reports that, for the last 12 months, the companies have worked together to develop active ingredient compositions that comprise varying concentrations of Selektope, Sea-Nine 211N And Sea-Nine Ultra with other commonly used ingredients for marine antifoulant applications.
A total of 35 paint formulations with a 12-month lifespan were reportedly developed and put into static testing environments in the Caribbean, Eastern North Sea, North Mediterranean and in the Japanese Sea. I-Tech reports that this joint research and development work is the first time these solutions have been used as co-biocides in marine antifouling coating formulations.
Additionally, the test paint formulations had performed “as good, or better than, the commercial paint references” after six months of testing. Formulations with Sea-Nine Ultra (2%) and Selektope (0.1%) reportedly showed excellent performance at reduced biocide concentrations.
Other Recent Selektope Research
In November, I-Tech and RISE Research Institutes of Sweden announced that they have developed a new method for introducing its barnacle repelling active agent into marine antifouling coatings.
I-Tech and RISE collaborated over the past five years on a series of projects to improve the use of Selektope in biocidal antifouling coatings for its barnacle fouling prevention characteristics. With the success of biocidal coatings dependent on the sustained control of biocide released at the coating surface, the team looked at previous elements that made antifouling coatings successful.
Selektope is currently delivered to the surface of self-polishing copolymer (SPC) antifouling coatings due to being held in the coating matrix via electrostatic interactions with metal pigments, allowing the technology to be evenly dispersed throughout the coating matrix and released at a sustained rate as the paint erodes or polishes.
However, the success of biocidal coatings is reportedly dependent on the sustained control of biocide release at the coating surface across the entire intended lifespan of a coating system. For large merchant ships, this period could be up to 60 months.
In other research, superior antifouling efficacy was achieved when a biocide was attached to a polymer chain with a covalent bond that was hydrolysable upon contact with water. Before the ban of tributyltin (TBT) use in 2008, this release mechanism is reportedly what gave TBT-containing coatings their success.
Researchers from I-Tech and RISE then began to look at ways of attaching Selektope to a co-polymer chain via the creation of Selektope-containing monomers that could be polymerized.
To test this idea, several coating SPC copper-free formulations on control panels were tested off the west coast of Sweden for 10 months, including:
Following this experiment, I-Tech and RISE reported that the control panel displayed heavy barnacle fouling whereas the panels coated with paints containing Selektope, both introduced via the traditional method and via the new method of attachment to a co-polymer chain, were barnacle-free.
The researchers said these results provided proof of concept that attaching Selektope to a co-polymer for use in SPC antifouling coatings is possible.
