Interestingly, there were three chemical systems that worked:
> 1:2 tetrabutylammonium bromide ([N4444]Br):decanoic acid
> 1:2 tetraoctylammonium bromide ([N8888]Br):decanoic acid
> 1:1 thymol:menthol
Unfortunately, none of them are great, and this method is going to be quite limited unless better chemical agents are found. Treating even 0.05% of the ocean's surface water with tetrabutylammonium bromide would require a vast fraction of the world's annual bromine production. It would possibly even call for quantities of bromine that exceed the world's current supply. Besides, bromine leakage could be just as bad -- or worse -- than microplastic contamination, as bromine is biologically active in an obvious and straightforward way, whereas the biological effects of microplastics are still a matter of some debate.
And of course there's not nearly enough thymol or menthol...
So this is interesting for bottled water companies, but not (yet) as an environmental remediation method.