title: Redox-responsive gels with tunable hydrophobicity for controlled solubilization and release of organics.
abstract: The hydrophobicity of the chemical environment within a redox-responsive polymer gel synthesized by copolymerization of hydroxybutyl methacrylate (HBMA) and vinylferrocene (VF) can be controlled by tuning the oxidation state of the redox-responsive moiety, ferrocene. When ferrocene is in the uncharged reduced state, the gel is hydrophobic and selectively extracts butanol from aqueous solution. Upon oxidation to ferricenium ions, charge is induced at the ferrocene sites making the gel hydrophilic, with a reduced capacity for butanol relative to water. Equilibrium distribution coefficients and separation factors provide quantitative evidence for this changing preference for butanol depending on oxidation state. The selection of the monomer constituting the polymer backbone, HBMA, was based on an initial screening using the Hansen solubility parameters of commercially available monomers. The effect of the various constituents of the gel on the gel's butanol extraction ability has been ascertained experimentally.
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Abhinav
authors.initials: A
authors.lastname: Akhoury
authors.forename: Lev
authors.initials: L
authors.lastname: Bromberg
authors.forename: T Alan
authors.initials: TA
authors.lastname: Hatton