title: Boronic Acid Linear Homopolymers as Effective Emulsifiers and Gelators.
abstract: We report emulsion studies using poly(vinylphenyl boronic acid) (PVPBA) linear homopolymer as an effective emulsifier and gelator. Two stabilizing regimes were identified depending on the pH of PVPBA aqueous solutions, i.e., emulsions stabilized by the hompolymer nanoparticles (Pickering emulsions) at pH < pKa and emulsions stabilized by the homopolymer unimers at pH > pKa. In both cases, gelled emulsions were obtained from medium to high internal phase volume fractions with the unimers exhibiting more effective emulsification and gelling properties. Hydrogen bonding between the boronic acid units is proposed to account for the high strength of the emulsions. The emulsions were shown to be pH- and sugar-responsive. Finally, the stable emulsions were used as templates to directly prepare PVPBA macroporous materials and to fabricate multilayered capsules. This remarkable observation that a simple homopolymer can serve as an effective emulsifier and gelator may dramatically extend the scope of potential emulsifiers and inspire further research in the design of new types of efficient emulsifying agents.
authors.affiliation: Institute of Nanochemistry and Nanobiology, College of Environmental Science and Chemical Engineering, Shanghai University , Shanghai 200444, China.
authors.forename: Qijing
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Chemistry, University of Florida , Gainesville, Florida 32611, United States.
authors.forename: Megan R
authors.initials: MR
authors.lastname: Hill
authors.affiliation: Department of Chemistry, University of Florida , Gainesville, Florida 32611, United States.
authors.forename: William L A
authors.initials: WL
authors.lastname: Brooks
authors.affiliation: Institute of Nanochemistry and Nanobiology, College of Environmental Science and Chemical Engineering, Shanghai University , Shanghai 200444, China.
authors.forename: Anqi
authors.initials: A
authors.lastname: Zhu
authors.affiliation: Department of Chemistry, University of Florida , Gainesville, Florida 32611, United States.
authors.forename: Brent S
authors.initials: BS
authors.lastname: Sumerlin
authors.affiliation: Institute of Nanochemistry and Nanobiology, College of Environmental Science and Chemical Engineering, Shanghai University , Shanghai 200444, China.
authors.forename: Zesheng
authors.initials: Z
authors.lastname: An
keywords: H bonding; emulsions; gels; interfaces; polymers