Small molecule surfactants suffer from limited efficiency in oil-spill remediation due to their inability to form micelles in dilute solution below a critical micelle concentration (CMC). Statistical ampiphillic copolymers or “polysoaps” are viable alternatives since each copolymer chain can form its own unimeric micelle with no CMC limitation. Our group has previously reported first-generation versions of these micelles capable of hydrocarbon sequestration. Those systems relied on indigenous bacteria for oil remediation and were permanently water-soluble. Our present goal is to develop second generation, stimuli-responsive systems that would allow removal of sequestered foulants as well as recycling of the “polysoaps”. In this work, we have prepared a series of “polysoaps” via the RAFT copolymerization of methacrylol sulfacetamide (mSAC) and methacrylol sulfamethazine (mSMZ). These monomers were chosen to have different pKa values (5.3 and 7.9, respectively) and thus sharp segmental solubility transitions upon ionization in water at values of pH &gt; pKa. By incorporating the two sulfonamide-based monomers into a copolymer backbone, we aim to create three distinct phase responses by adjusting pH; full water solubility at alkaline pH, micelle formation at neutral pH, and phase separation at acidic pH. This tri-phasic behavior will allow for hydrocarbon sequestration and removal from water followed by hydrocarbon recovery and separation from the copolymer. The copolymer can, in principle, be recycled-potentially improving markedly the efficiency of current oil spill remediation technologies.

pH responsive sulfonamide-based polysoaps via RAFT copolymerization for oil remediation and recovery

255th National Meeting (2018)

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