A one-pot synthesis approach is described to generate ordered mesoporous crystalline g-alumina-carbon composites and ordered mesoporous crystalline g-alumina materials via the combination of soft and hardtemplating chemistries using block copolymers as soft structure-directing agents. Periodically ordered alumina hybrid mesostructures were generated by self-assembly of a poly(isoprene)-block-poly(styrene)-block-poly(ethylene oxide) terpolymer, n-butanol and aluminum tri-sec-butoxide derived sols in organic solvents. The triblock terpolymer was converted into a rigid carbon framework during thermal annealing under nitrogen to support and preserve the ordered mesoporous crystalline g-alumina-carbon composite structures up to 1200 C. The carbon matrix was subsequently removed in a second heat treatment in air to obtain ordered mesoporous crystalline g-alumina structures. Such thermally stable, highly crystalline, and periodically ordered mesoporous ceramic and ceramic-carbon composite materials may be promising candidates for various high temperature catalysis, separation, and energyrelated applications.

Hierarchically porous materials are becoming increasingly important in catalysis, separation, and energy applications due to their advantageous diffusion and flux properties. Here we present the synthesis of hierarchically macro-and mesoporous carbon materials with graded porosity from a one-pot fabrication route. Organic−polymeric hybrids of a carbon precursor and poly(isoprene)-block-poly(styrene)-block-poly(4-vinylpyridine) with graded porosity are obtained via coassembly and nonsolventinduced phase separation. The membranes were carbonized at temperatures as high as 1100°C with simultaneous decomposition of the block copolymer. The carbon materials show an open nanoporous top surface with narrow pore-size distribution that opens up into a graded macroporous support with increasing macropore size along the film normal and mesoporous walls, providing for highly accessible porosity with a large surface area of over 500 m 2 g −1 . Further, we expand the direct synthesis process to form well-dispersed metal nanoparticles (such as nickel and platinum) on the graded, hierarchically porous carbon materials. Our one-pot synthesis offers a facile approach to graded macroand mesoporous carbons. M esoporous materials have been used for a wide range of applications including biomedical implants, water filtration, and energy devices, due to their high surface areas and pore volumes. In particular, mesoporous inorganic materials such as carbon, metal, and metal oxide materials have been employed for energy conversion and storage applications, as well as catalysis and separation. 1−9 In order to increase the accessibility of mesoporous materials and to promote diffusion and material flux for both gases and liquids, hierarchical meso-and macroporosity has been demonstrated to be advantageous. Furthermore, graded macroporosity featuring a continuous increase in pore size along at least one direction can combine high material flux with good separation resolution in membrane applications. 10,11 Graded porosity has also shown promise in minimizing mass transport resistance to either liquids or gases as well as increasing catalyst utilization and power density in fuel cell electrode materials. 12,13 Combining the synthesis of inorganic materials with polymer fabrication techniques in soft-or hard-templating processes opens the door to facile scalability and compatibility with roleto-role processing for low-cost, large-area fabrication. Numerous ordered mesoporous carbons from block copolymer (BCP) soft-templating have been reported with pore sizes of below 15 nm for Pluronics templates and up to 40 nm with high molar mass BCPs. Surface areas range from 150 to 1000 m 2 g −1 , dependent on pore size, carbonization temperature, and microporosity. 14−19 Only a few hierarchical macro-and mesoporous carbons have been reported using one-pot hydrothermal synthesis or spinodal decomposition. 20,21 Recently, BCPs have been used for the fabrication of graded, hierarchically macro-and mesoporous polymer membranes with ordered features on th...

Porous materials design often faces a trade-off between the requirements of high internal surface area and high reagent flux. Inorganic materials with asymmetric/hierarchical pore structures or well-defined mesopores have been tested to overcome this trade-off, but success has remained limited when the strategies are employed individually. Here, the attributes of both strategies are combined and a scalable path to porous titanium nitride (TiN) and carbon membranes that are conducting (TiN, carbon) or superconducting (TiN) is demonstrated. These materials exhibit a combination of asymmetric, hierarchical pore structures and welldefined mesoporosity throughout the material. Fast transport through such TiN materials as an electrochemical double-layer capacitor provides a substantial improvement in capacity retention at high scan rates, resulting in state-of-the-art power density (28.2 kW kg −1 ) at competitive energy density (7.3 W-h kg −1 ). In the case of carbon membranes, a record-setting power density (287.9 kW kg −1 ) at 14.5 W-h kg −1 is reported. Results suggest distinct advantages of such pore architectures for energy storage and conversion applications and provide an advanced avenue for addressing the trade-off between high-surface-area and high-flux requirements.

Inorganic materials with asymmetric pore structures provide increased accessibility and flux, making them attractive for applications in energy conversion and storage, separations, and catalysis. Non-equilibrium-based block copolymer structure-directed self-assembly approaches provide routes to obtaining such materials. We report a one-pot synthesis using the co-assembly and non-solvent-induced phase separation (CNIPS) of poly­(isoprene)-b-poly­(styrene)-b-poly­(4-vinylpyridine) (ISV) triblock terpolymer and phenol formaldehyde resols. After heat-treatment, carbon materials with asymmetric pore structures result. They have a mesoporous top surface atop a porous support with graded porosity along the film normal. The walls of the macroporous support are also mesoporous, providing an additional structural hierarchy and increased specific surface area. We demonstrate how successfully navigating the pathway complexity associated with the nonequilibrium approach of CNIPS enables switching from disordered to ordered top surfaces in the as-made organic–organic hybrids and resulting carbon materials after thermal treatments. To that end, a combination of ex situ transmission small-angle X-ray scattering (SAXS) of the membrane dope solutions, in situ grazing-incidence SAXS (GISAXS) after dope solution blading and during solvent evaporation, and scanning electron microscopy (SEM) of the final membrane structures was used. We expect the final porous carbon materials exhibiting a combination of asymmetric, hierarchical pore structures and well-defined mesoporosity throughout the material to be of interest for a number of applications, including batteries, fuel cells, electrochemical double-layer capacitors, and as catalyst supports.

Block copolymer (BCP)-derived asymmetric ultrafiltration membranes combine the BCP self-assembly with nonsolvent-induced phase separation (SNIPS). To understand the structural evolution in membrane top separation layers made from polyisoprene-b-polystyrene-b-poly­(4-vinylpyridine) (ISV) in dioxane (DOX) and tetrahydrofuran (THF) all the way to the final membrane, we combined solution small-angle X-ray scattering (SAXS), estimated solution concentrations and compositions upon solvent evaporation, in situ grazing-incidence SAXS (GISAXS), spin–spin relaxation time (T 2) analysis by solution 1H NMR, and scanning electron microscopy (SEM). Above the critical micelle concentration (<1 wt % ISV), solvent evaporation drives micelles with poly­(4-vinylpyridine) (P4VP) in the core across disorder-to-order and order-to-order transitions, the latter in part driven by the segregation of polyisoprene (PI)- from polystyrene (PS)-blocks. Extended to polystyrene-b-poly­(4-vinylpyridine) (SV) in dimethylformamide (DMF) and THF, results suggest that, in particular, T 2 relaxation analysis by 1H NMR is a powerful tool in analyzing which blocks form micelle core and which form corona chains. We expect insights to help develop next-generation SNIPS membranes for applications, e.g., in clean water and biopharmaceutical separations.