Particle-stabilized surfactant-free medium internal phase emulsions as templates for porous nanocomposite materials: poly-Pickering-Foams

Emulsion template fabricated heterogeneous bilayer gelatin-based scaffolds with sustained-delivery of lycium barbarum glycopeptide for periodontitis treatment

Periodontitis is a chronic inflammatory disease raising the risks of tooth-supporting structures destruction and even tooth loss. The way to reconstruct periodontal bone tissues in inflammatory microenvironment has been long in demand for periodontitis treatment. In this study, the lycium barbarum glycopeptide (LbGP) loaded gelatin-based scaffolds were fabricated for periodontitis treatment. Gelatin microspheres with suitable size were prepared by emulsification and gathered by oxidized sodium alginate to prepare heterogeneous bilayer gelatin-based scaffolds, and then they were loaded with LbGP. The prepared scaffolds possessed interconnected porous microstructures, good degradation properties, sufficient mechanical properties, sustained release behavior and well biocompatibility. In vitro experiments suggested that the LbGP loaded gelatin-based scaffolds could inhibit the expression of inflammatory factors (IL-1β, IL-6, and TNF-α), promote the expression of anti-inflammatory factor (IL-10), and the expression of osteogenic markers (BMP2, Runx2, ALP, and OCN) in PDLSCs under the LPS-stimulated inflammatory microenvironment. Moreover, in rat periodontitis models, the LbGP gelatin-based scaffolds would reduce the alveolar bone resorption of rats, increase the collagen fiber content of periodontal membrane, alleviate local inflammation and improve the expression of osteogenesis-related factors. Therefore, the LbGP loaded gelatin-based scaffolds in this study will provide a potential therapeutic strategy for periodontitis treatment.

Emulsion template fabricated gelatin-based scaffold functionalized by dialdehyde starch complex with antibacterial antioxidant properties for accelerated wound healing

Gelatin and starch are considered as promising sustainable materials for their abundant production and good biodegradability. Efforts have been made to explore their medical application. Herein, scaffolds based on gelatin and starch with a preferred microstructure and antibacterial antioxidant property were fabricated by the emulsion template method. The dialdehyde starch was firstly combined with silver nanoparticles and curcumin to carry out the efficient hybrid antibacterial agent. Then, the gelatin microsphere of appropriate size was prepared by emulsification and gathered by the above agent to obtain gelatin-based scaffolds. The prepared scaffolds showed porous microstructures with high porosity of over 74 % and the preferred pore sizes of ∼65 μm, which is conducive to skin regeneration. Moreover, the scaffolds possessed a good swelling ability of over 640 %, good degradability of over 18 days, excellent blood compatibility, and cell compatibility. The promising antibacterial and antioxidant properties came from the hybrid antibacterial agent were affirmed. As expected, the gelatin-based scaffolds fabricated by the emulsion template method with a preferred microstructure can facilitate more adhered fibroblasts. In summary, gelatin-based scaffolds functionalized by starch-based complex expanded the application of abundant sustainable materials in the biomedical field, especially as antibacterial antioxidant wound dressings.

Hydroxyapatite nanoparticle-modified porous bone grafts with improved cell attachment

Emulsion-templated foams have displayed promise as injectable bone grafts; however, the use of a surfactant as an emulsifier resulted in relatively small pores and impedes cell attachment. Hydroxyapatite nanoparticles were explored as an alternative stabilizer to address these limitations. To this end, hydroxyapatite nanoparticles were first modified with myristic acid to generate the appropriate balance of hydrophobicity to stabilize a water-in-oil emulsion of neopentyl glycol diacrylate and 1,4-butanedithiol. In situ surface modification of the resulting foam with hydroxyapatite was confirmed with elemental mapping and transmission electron microscopy. Nanoparticle-stabilized foams displayed improved human mesenchymal stem cell viability (91 ± 5%) over surfactant-stabilized foams (23 ± 11%). Although the pore size was appropriate for bone grafting applications (115 ± 71 μm), the foams lacked the interconnected architecture necessary for cell infiltration. We hypothesized that a co-stabilization approach with both surfactant and nanoparticles could be used to achieve interconnected pores while maintaining improved cell attachment and larger pore sizes. A range of hydroxyapatite nanoparticle and surfactant concentrations were investigated to determine the effects on microarchitecture and cell behavior. By balancing these interactions, a co-stabilized foam was identified that possessed large, interconnected pores (108 ± 67 μm) and improved cell viability and attachment. The co-stabilized foam was then evaluated as an injectable bone graft including network formation, microscale integration with bone, push out strength, and compressive properties. Overall, this work demonstrated that in situ surface modification with nHA improved cell attachment while retaining desirable bone grafting features and injectability.

Highly Porous Polymer Beads Coated with Nanometer-Thick Metal Oxide Films for Photocatalytic Oxidation of Bisphenol A

Highly porous metal oxide-polymer nanocomposites are attracting considerable interest due to their unique structural and functional features. A porous polymer matrix brings properties such as high porosity and permeability, while the metal oxide phase adds functionality. For the metal oxide phase to perform its function, it must be fully accessible, and this is possible only at the pore surface, but functioning surfaces require controlled engineering, which remains a challenge. Here, highly porous nanocomposite beads based on thin metal oxide nanocoatings and polymerized high internal phase emulsions (polyHIPEs) are demonstrated. By leveraging the unique properties of polyHIPEs, i.e., a three-dimensional (3D) interconnected network of macropores, and high-precision of the atomic-layer-deposition technique (ALD), we were able to homogeneously coat the entire surface of the pores in polyHIPE beads with TiO2-, ZnO-, and Al2O3-based nanocoatings. Parameters such as nanocoating thickness, growth per cycle (GPC), and metal oxide (MO) composition were systematically controlled by varying the number of deposition cycles and dosing time under specific process conditions. The combination of polyHIPE structure and ALD technique proved advantageous, as MO-nanocoatings with thicknesses between 11 ± 3 and 40 ± 9 nm for TiO2 or 31 ± 6 and 74 ± 28 nm for ZnO and Al2O3, respectively, were successfully fabricated. It has been shown that the number of ALD cycles affects both the thickness and crystallinity of the MO nanocoatings. Finally, the potential of ALD-derived TiO2-polyHIPE beads in photocatalytic oxidation of an aqueous bisphenol A (BPA) solution was demonstrated. The beads exhibited about five times higher activity than nanocomposite beads prepared by the conventional (Pickering) method. Such ALD-derived polyHIPE nanocomposites could find wide application in nanotechnology, sensor development, or catalysis.

High Internal Phase Emulsion Stabilization through Restricted Interdrop Fusion across Water Drainage Channels

This study introduces a promising approach to stabilize high internal phase emulsions (HIPEs) in which droplets are enveloped by octadecane (C18)-grafted bacterial cellulose nanofibers (BCNF_diC18), which are mainly surrounded by carboxylate anions and hydrophobically modified with C18 alkyl chains. For this purpose, BCNF_diC18, in which two octadecyl chains were grafted onto each of several cellulose unit rings on 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidized BCNFs, was fabricated using the Schiff base reaction. The wettability of BCNF_diC18 was adjusted by controlling the amount of the grafted C18 alkyl chain. Interfacial rheological analysis revealed that BCNF_diC18 enhanced the membrane modulus at the oil-water interface. We figured out that such a resilient interfacial membrane substantially prevented interdrop fusion across the water drainage channel formed between the jammed oil droplets, which was confirmed theoretically using the modified Stefan-Reynolds equation. These findings highlight that the use of surfactants in the form of nanofibers to form a rigid interfacial film plays a key role in hindering the interfusion of the internal phase and the collapse of the emulsion, which is essential for HIPE stabilization.

Destabilization of Pickering emulsions by interfacial transport of mutually soluble solute

HYPOTHESIS

Pickering emulsions (PEs) once formed are highly stable because of very high desorption energies (∼10⁷ k_BT) associated with particles adsorbed to the interfaces. The destabilization of PEs is required in many instances for recovery of valuable chemicals, products and active compounds. We propose to exploit interfacial instabilities develop by the addition of different types of solutes to PEs as a route to engineer their destabilization.

EXPERIMENTS

PEs stabilized by (i) spherical particles, (ii) non-spherical particles, (iii) oppositely charged particle-particle mixtures, and (iv) oppositely charged particle-polyelectrolyte mixtures are formulated. Different types of solutes are added to these highly stable PEs and the macroscopic as well as microscopic changes induced in the PEs is recorded by visual observation and bright field optical microscopy.

FINDINGS

Our results point to a simple yet robust method to induce destabilization of PEs by transiently perturbing the oil-water interface by transport of a mutually soluble solute across the interface. The generality of the method is demonstrated for different kind of solutes and stabilizers including particles of different sizes (nm to µm), shapes (sphere, spheroids, spherocylinders) and types (polystyrene, metal oxides). The method works for both oil-in-water (o/w) and water-in-oil (w/o) PEs with different kinds of non-polar solvents as oil-phase. However, the method fails when the solute is insoluble in one of the phases of PEs. The study opens up a new approach to destabilization of particle stabilized emulsions.

Polystyrene Macroporous Magnetic Nanocomposites Synthesized through Deep Eutectic Solvent-in-Oil High Internal Phase Emulsions and Fe3O4 Nanoparticles for Oil Sorption

In this work, we report a nonaqueous one-step method to synthesize polystyrene macroporous magnetic nanocomposites through high internal phase emulsions (HIPEs) formulated with the deep eutectic solvent (DES) composed of urea:choline chloride (U:ChCl, in a 2:1 molar ratio) as the internal phase and co-stabilized with mixtures of Span 60 surfactant and non-functionalized magnetite nanoparticles (Fe₃O₄ NPs). The porous structure and the magnetic and lipophilic properties of the nanocomposite materials were easily tailored by varying the amount of Fe₃O₄ NPs (0, 2, 5 and 10 wt %) and the surfactant Span 60 (0, 5, 10, and 20 wt %) used in the precursor emulsion. The resultant nanocomposite polyHIPEs exhibit high sorption capacity toward different oils (hexane, gasoline, and vegetable oil) due to their high porosity, interconnectivity, and hydrophobic surface. It was observed that the oil sorption capacity was improved when the amount of surfactant decreased and Fe₃O₄ NPs increased in HIPE formulation. Therefore, polyHIPE formulated with 5 and 10 wt % Span 60 and Fe₃O₄ NPs, respectively, showed the highest oil sorption capacities of 4.151, 3.556, and 3.266 g g^-1 for gasoline, hexane, and vegetable oil, respectively. In addition, the magnetic monoliths were reused for more than ten sorption/desorption cycles without losing their oil sorption capacity.

Emulsion-Templated, Magnetic, Hydrophilic-Oleophobic Composites for Controlled Water Removal

Emulsion-templated, hydrophilic-oleophobic porous materials are promising for the removal of a small amount of water from oil-water mixtures, but the maneuver and complete collection of these porous materials are challenging. Herein, we report the fabrication of magnetic, hydrophilic-oleophobic polyHIPE composites from reactive Fe₃O₄ nanoparticle-stabilized high internal phase emulsions through simultaneous bulk polymerization of water-soluble monomers and interface-catalyzed polycondensation of 1H,1H,2H,2H-perfluorooctyltriethoxysilane. The resulting composites were hydrophilic-oleophobic, with water droplets rapidly absorbed (within 20 s), and exhibited designable magnetic responsiveness. The hydrophilicity-oleophobicity enabled water to be removed through selective absorption from oil-water mixtures (including surfactant-stabilized water-in-oil emulsions), with a high separation rate over 99%. The magnetic-responsiveness enabled both the dry and the swollen composites to be maneuvered in a remote and contactless manner and to be fully collected. Therefore, the magnetic, hydrophilic-oleophobic polyHIPE composites are excellent candidates for the removal of water from water-oil mixtures with complete collection.

Advanced Switchable Molecules and Materials for Oil Recovery and Oily Waste Cleanup

Advanced switchable molecules and materials have shown great potential in numerous applications. These novel materials can express different states of physicochemical properties as controlled by a designated stimulus, such that the processing condition can always be maintained in an optimized manner for improved efficiency and sustainability throughout the whole process. Herein, the recent advances in switchable molecules/materials in oil recovery and oily waste cleanup are reviewed. Oil recovery and oily waste cleanup are of critical importance to the industry and environment. Switchable materials can be designed with various types of switchable properties, including i) switchable interfacial activity, ii) switchable viscosity, iii) switchable solvent, and iv) switchable wettability. The materials can then be deployed into the most suitable applications according to the process requirements. An in-depth discussion about the fundamental basis of the design considerations is provided for each type of switchable material, followed by details about their performances and challenges in the applications. Finally, an outlook for the development of next-generation switchable molecules/materials is discussed.

pH-Responsive Pickering emulsions stabilized solely by surface-inactive nanoparticles via an unconventional stabilization mechanism

Using solely highly hydrophilic particles to stabilize emulsions, especially high internal phase emulsions, has always been an important challenge. Here pH-responsive Pickering emulsions stabilized by a low concentration of bare highly hydrophilic Ludox CL nanoparticles without surface modification or addition of surfactants are developed at neutral pH. The dispersed nanoparticles can be transformed into an aggregate state with a network-like structure near the isoelectric point, which contributes to the stabilization of the emulsions. Moreover, the vdW attraction between particles and droplets also plays a key role in the formation of emulsions, which can make the aggregated nanoparticles adsorb tightly around the droplets rather than penetrate the oil-water interface. The formed protective armor and network-like aggregates separate droplets from each other to prevent coalescence. At a low nanoparticle concentration (0.5 wt%), a high internal phase emulsion can be formed and can last up to half a year. This system can emulsify not only the hydrocarbon oil but also the fluoroalkane oil phase. Finally, organic-inorganic composite particles are fabricated using the template action of the Pickering emulsions. The method of preparing composite particles is more convenient than the traditional Pickering emulsion polymerization which often requires the modification of the surface of the hydrophilic particles or the addition of auxiliary monomers. This study provides a simple green strategy for the preparation of a more stable Pickering emulsion stabilized by surface-inactive nanoparticles and will broaden the scope of applications.

PolyHIPE foams from pristine graphene: Strong, porous, and electrically conductive materials templated by a 2D surfactant

Graphene is attractive as a functional 2D surfactant for polymerized high internal phase emulsions (polyHIPEs) due to its remarkable mechanical and electrical properties. We have developed polyHIPEs stabilized by pristine, unoxidized graphene via the spontaneous exfoliation of graphite at high-energy aqueous/organic interfaces. The exfoliated graphene self-assembles into a percolating network and incorporates into the polyHIPE cell walls as verified by TEM. The resulting composites showed compressive strengths of 7.0 MPa at densities of 0.22 g/cm³ and conductivities up to 0.36 S/m. Systematically reducing the concentration of monomer in the oil phase by dilution with a porogenic-acting solvent increased the porosity and lowered the density of the polyHIPEs. Characterization of these composites indicated that graphene's high compressive strength and modulus was transferred to the polyHIPEs and provided mechanical reinforcement even at low polymer content. SEM showed that the morphology of the polymer changed with decreasing monomer content while the graphene lined cells retained their shape. Moreover, we show that the polyHIPEs contain a continuous graphene percolating network resulting in electrically conductive materials at low graphene loading.

Emulsions Stabilized with Alumina-Functionalized Mesoporous Silica Particles

Alumina-functionalized ordered mesoporous silica SBA-15 particles have been proposed to stabilize Pickering emulsions. Functionalization of SBA-15 particles have been performed by depositing alumina using a two-step synthesis (first, silica condensation, followed by alumina precipitation). Three different Al to Si ratios have been prepared. The calcined materials have been characterized by TEM, SEM, XRD, N₂ physisorption, and zeta potential, in order to determine key physicochemical properties, and the alumina localization. The emulsifying and stabilizing properties of the calcined particles have been evaluated for water/toluene-based Pickering emulsions.

Facile synthesis of templated macrocellular nanocomposite scaffold via emulsifier-free HIPE-ROP

High internal phase emulsion (HIPE)-templated macrocellular nanocomposite scaffolds of crosslinked poly(ε-caprolactone) were produced using an emulsifier-free, single-step synthesis and showed superior resiliency and sorption capacity.

Encapsulating an organic phase change material within emulsion-templated poly(urethane urea)s

Interfacial step growth polymerization within oil-in-water high internal phase emulsions was used to synthesize poly(urethane urea) monoliths, consisting of 90% organic phase change material encapsulated within micrometer-scale capsules, for thermal energy storage and release applications.

Hierarchical Porous Protein Scaffold Templated from High Internal Phase Emulsion Costabilized by Gelatin and Gelatin Nanoparticles

Recently, three-dimensional (3D) scaffolds produced using poly-Pickering high internal phase emulsions (polyHIPEs) technology are particularly attractive in biomedical application. However, until now the most investigated polyHIPEs are hydrophobic composites originating from synthetic polymers. Here we present an investigation of a hierarchical porous protein scaffold templated from oil-in-water (O/W) HIPEs costabilized by fully natural materials, gelatin, and gelatin nanoparticles. Fairly monodispersed gelatin nanoparticles were first synthesized through a two-step desolvation method, and then they were used as emulsifiers together with gelatin to fabricate stable HIPEs with adjustable droplet size distribution and rheology. Monolithic scaffolds were formed by cross-linking the HIPEs with polymers as low as 2.5 wt % in the continuous phase, which appropriately presented a general high porosity and had an interconnected porous morphology with smooth pore walls and textured structures. Furthermore, the scaffolds were degradable and showed reasonably good biocompatibility; L929 cells could adhere to the surface of the materials and exhibited intensive growth and well-spread morphology. This hierarchical porous protein scaffold could, therefore, have important application as a 3D scaffold that offers enhanced cell adhesion and functionality.

Inverse Pickering Emulsion Stabilized by Exfoliated Hexagonal-Boron Nitride (h-BN)

The formation of inverse Pickering emulsions using exfoliated hexagonal boron nitride (h-BN) as an effective particulate stabilizer without using any surfactants is reported for the first time. The stability and the type of h-BN Pickering emulsions formulated with different BN concentrations and by varying oil/water (o/w) ratios are studied and discussed. First the emulsion structure is analyzed microscopically through optical and epifluorescence microscopy and macroscopically by the study of the rheological behavior. The average droplet size decreases with h-BN concentration whereas the emulsions achieve good stability at 2 wt % BN concentrations and for a 1:1 o/w ratio. In all formulations, the emulsions are of water-in-oil (w/o) type due mainly to the hydrophobicity of h-BN.

Pickering Membranes Stabilized by Saturn Particles

We report on a novel method to synthesize particles-called by us Saturn particles-having two hydrophobic caps that oppose each other and are separated from each other by a hydrophilic belt that encircles the particle. Mixtures of these particles with water and air, without the usage of low molar mass surfactants, easily form Pickering foams and Pickering membranes that are stable for days. These Pickering membranes are composed of a thin film of water into which the particles are embedded in such a way that the belt is surrounded by the water and the caps protrude out of the water into the air at the top and bottom side of the water film. As expected for a liquid membrane, these Pickering membranes are permeable for gases, with the permeance being proportional to the solubility and diffusion coefficient of the gas considered. Experimentally obtained permeance values agree reasonably well with theoretical calculations.

Fabrication of CMC-g-PAM Superporous Polymer Monoliths via Eco-Friendly Pickering-MIPEs for Superior Adsorption of Methyl Violet and Methylene Blue

A series of superporous carboxymethylcellulose-graft-poly(acrylamide)/palygorskite (CMC-g-PAM/Pal) polymer monoliths presenting interconnected pore structure and excellent adsorption properties were prepared by one-step free-radical grafting polymerization reaction of CMC and acrylamide (AM) in the oil-in-water (O/W) Pickering-medium internal phase emulsions (Pickering-MIPEs) composed of non-toxic edible oil as a dispersion phase and natural Pal nanorods as stabilizers. The effects of Pal dosage, AM dosage, and co-surfactant Tween-20 (T-20) on the pore structures of the monoliths were studied. It was revealed that the well-defined pores were formed when the dosages of Pal and T-20 are 9–14 and 3%, respectively. The porous monolith can rapidly adsorb 1,585 mg/g of methyl violet (MV) and 1,625 mg/g of methylene blue (MB). After the monolith was regenerated by adsorption-desorption process for five times, the adsorption capacities still reached 92.1% (for MV) and 93.5% (for MB) of the initial maximum adsorption capacities. The adsorption process was fitted with Langmuir adsorption isotherm model and pseudo-second-order adsorption kinetic model very well, which indicate that mono-layer chemical adsorption mainly contribute to the high-capacity adsorption for dyes. The superporous polymer monolith prepared from eco-friendly Pickering-MIPEs shows good adsorption capacity and fast adsorption rate, which is potential adsorbent for the decontamination of dye-containing wastewater.

Interconnected macroporous 3D scaffolds templated from gelatin nanoparticle-stabilized high internal phase emulsions for biomedical applications

Here we report on the successful preparation of open-cellular macroporous 3D scaffolds templated from gelatin nanoparticle-stabilized HIPEs with acrylamide (AM) as the monomer in the continuous phase. Tuning the gelatin nanoparticle concentration or AM content led to different porous structures with void diameters varying between 30 and 78 μm. More importantly, keeping HIPEs at room temperature to undergo a limited kinetic coarsening before polymerization could greatly improve the interconnectivity and pore size of the scaffolds, with the average diameters (approx. 118 μm) being enlarged 1.5-fold. Additionally, the scaffolds had a character of soft tissue with compressive modulus more than 150 kPa. The cell culture assay confirmed that HepG2 cells not only could adsorb on but also were grown inside the scaffolds, representing a characteristic of the good biocompatibility of the scaffolds. Our work suggests that the 3D scaffolds fabricated from gelatin nanoparticle-stabilized HIPE templates are promising culture substrates for a wide range of applications in the biomedical field.

Hierarchically porous materials: synthesis strategies and structure design

This review addresses recent advances in synthesis strategies of hierarchically porous materials and their structural design from micro-, meso- to macro-length scale.

Deep-Eutectic Solvents as MWCNT Delivery Vehicles in the Synthesis of Functional Poly(HIPE) Nanocomposites for Applications as Selective Sorbents

We report an alternative green strategy based on deep-eutectic solvents (DES) to deliver multiwalled carbon nanotubes (MWCNTs) for a bottom-up approach that allows for the selective interfacial functionalization of nonaqueous poly(high internal phase emulsions), poly(HIPEs). The formation and polymerization of methacrylic and styrenic HIPEs were possible through stabilization with nitrogen doped carbon nanotube (CN_X) and surfactant mixtures using a urea-choline chloride DES as a delivering phase. Subtle changes in CN_X concentration (less than 0.2 wt % to the internal phase) produced important changes in the macroporous monolith functionalization, which in turn led to increased monolith hydrophobicity and pore openness. These materials displayed great oleophilicity with water contact angles as high as 140° making them apt for biodiesel, diesel, and gasoline fuel sorption applications. Overall, styrene divinylbenzene (StDvB) based poly(HIPEs) showed hydrophobicity and fuel sorption capacities as high as 4.8 (g/g). Pore hierarchy, namely pore openness, regulated sorption capacity, and sorption times where greater openness resulted in faster sorption and increased sorption capacity. Monoliths were subject to 20 sorption-desorption cycles demonstrating recyclability and stable sorption capacity. Finally, CN_X/surfactant hybrids made it possible to reduce surfactant requirements for successful HIPE formation and stabilization during polymerization. All poly(HIPEs) retained acceptable conversion as a function of CN_X loading nearing 90% or better with thermal stability as high as 283 °C.

Synthesis and characterization of polyHIPE composites containing halloysite nanotubes

High internal phase emulsion templated-polymer (polyHIPE) composites were prepared from spirulina modified halloysite (HL) nanotube containing styrene/divinylbenzene based water-in-oil type concentrated emulsions. In order to obtain a stable emulsion for neat polyHIPE’s synthesis, at least 5 vol% Span-80 as a non-ionic surfactant, with respect to organic phase was needed. For syntheses of polyHIPE composite structures, this amount was decreased to 2 vol%, even in presence of 0.25 wt% modified nanotube with respect to the organic phase. All the polyHIPE composites exhibited open pore structures with pore interconnections together with partially or completely closed pores. The composite having 0.25 wt% modified nanotube and 2 vol% surfactant was found to have about 260% higher dye adsorption capacity and the highest onset degradation temperature in comparison with neat polyHIPE.

High-Surface-Area, Emulsion-Templated Carbon Foams by Activation of polyHIPEs Derived from Pickering Emulsions

Carbon foams displaying hierarchical porosity and excellent surface areas of >1400 m²/g can be produced by the activation of macroporous poly(divinylbenzene). Poly(divinylbenzene) was synthesized from the polymerization of the continuous, but minority, phase of a simple high internal phase Pickering emulsion. By the addition of KOH, chemical activation of the materials is induced during carbonization, producing Pickering-emulsion-templated carbon foams, or carboHIPEs, with tailorable macropore diameters and surface areas almost triple that of those previously reported. The retention of the customizable, macroporous open-cell structure of the poly(divinylbenzene) precursor and the production of a large degree of microporosity during activation leads to tailorable carboHIPEs with excellent surface areas.