Hypercrosslinked polyHIPEs as precursors to designable, hierarchically porous carbon foams

Abstract

Hierarchically porous carbon foams were produced by carbonization of hypercrosslinked polymerized high internal phase water-in-styrene/divinylbenzene emulsions (HIPEs). The hypercrosslinking of these poly(ST-co-DVB)HIPEs was achieved using a dimethoxymethane external crosslinker to ‘knit’ together aromatic groups within the polymers using FriedelCrafts alkylation. By varying the amount of divinylbenzene (DVB) in the HIPE templates and subsequent polymers, the BET surface area and micropore volume of the hypercrosslinked analogues can be varied systematically, allowing for the production of carbon foams, or ‘carboHIPEs’, with varied surface areas, micropore volumes and pore-size distributions. The carboHIPEs retain the emulsion-templated macropores of the original polyHIPE, display excellent electrical conductivities and have surface areas of up to 417 m2/g, all the while eliminating the need for inorganic templates. The use of emulsion templates allows for pourable, mouldable precursors to designable carbonaceous materials

Synthesis and in situ functionalization of microfiltration membranes via high internal phase emulsion templating

“…By varying the emulsification parameters and the composition of monomers or additives, the void and window sizes of polyHIPEs can be altered. PolyHIPEs that combine high surface area and porosity with excellent interconnectivity and mass transport properties are ideally suited for a variety of applications, such as supported organic chemistry, scaffolding for tissue engineering and column filtration/separation …”

The Chemistry of Porous Polymers: The Holey Grail

“…Post-synthesis hypercrosslinking of styrenic PHs via Friedel-Crafts reactions has been used to achieve PHs with specific surface areas as high as 1600 m 2 /g. [62,[98][99][100][101][102][103] BCP selfassembly, with semi-crystalline endblock domains and microphase-separated midblock domains, has been observed within the walls of a PH based on a methacrylated triblock copolymer as the only monomer. [104] Phase separation during polymerization and/or crosslinking was observed within HIPEs containing a significant amount of solvent in the external phase, achieving specific surface areas as high as 570 m 2 / g. [93,[105][106] The incorporation of other pore-generating processes within the PH walls includes the generation of highly porous PH walls using gel formation and drying and the generation of foamed PH walls using CO 2 -generating urea reactions.…”

“…Post‐synthesis hypercrosslinking of styrenic PHs via Friedel‐Crafts reactions has been used to achieve PHs with specific surface areas as high as 1600 m 2 /g . BCP self‐assembly, with semi‐crystalline endblock domains and microphase‐separated midblock domains, has been observed within the walls of a PH based on a methacrylated triblock copolymer as the only monomer .…”

Emulsion and Foam Templating—Promising Routes to Tailor‐Made Porous Polymers

“…Potential applications shown in Figure 2r equire accurate control over the structure of polymer foams and afundamen- [7] porous epoxy resin (unpublished own results), polystyrene foam; [8] middle:polystyrene foam, [9] chitosan foam, [10a] polystyrene foam; [9] bottom:polystyrene foam with apore size and porosity gradient,c hitosan foam with aporosity gradient, [10b] polystyrene foam with ap ore-size gradient. [12] Angewandte Chemie tal understanding of how the structure influences the mechanical and physical properties.T he mechanical properties of polymer foams are key to all applications;the choice of material defines the overall range of mechanical properties, which can be further modified by the materialsporosity,pore structure,and degree of interconnectivity.…”