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Zeolitic imidazolate frameworks (ZIFs), a subclass of metal organic frameworks, are built of tetrahedral metal ions bridged by imidazolates. They have permanent porosity and relatively high thermal and chemical stability, which make them attractive candidates for many industrial applications. In recent years, significant progress has been made in developing ZIFs into membranes and thin films for gas separation, liquid separation (pervaporation) and functional devices. Various techniques, such as direct synthesis, secondary synthesis, reactive seeding and functional chemicals as linkers, and contra-diffusion synthesis, have been reported for the fabrication of ZIF membranes and films. As ZIFs have good compatibility with polymers, they have been incorporated into polymers with high loadings to form mixed matrix membranes. The resulting symmetric dense or asymmetric composite membranes exhibit good performance in gas separation and liquid separation via pervaporation. The recent developments of ZIF membranes/films, ZIF-polymer mixed matrix membranes and their applications are reviewed in this article. [ABSTRACT FROM AUTHOR]

Dense ceramic membranes with H+ or O2− conductivity have been widely used for fuel production through electro-hydrogenation/dehydrogenation or electro-oxygenation/deoxygenation. Electrochemical conversion processes demonstrate advantages over conventional redox reaction processes in terms of capital cost, energy savings, process intensification and product selectivity. Intermittent renewable power (e.g., solar and wind power) can be used to drive electrochemical processes so that renewable energy is stored in fuels as energy carriers, including hydrogen, ammonia, syngas, methane and ethylene. This review summarizes the pathways to store renewable energy via ion-conducting membrane reactors and discusses the commercialization progress and prospects of these energy technologies. [ABSTRACT FROM AUTHOR]

This paper presents the preparation of crystalline mesoporous titanias using furfuryl alcohol as a polymerizable solvent and titanium(IV) butoxide as a titania source. In the synthesis, furfuryl alcohol (FA) initially stabilized titanium(IV) butoxide through alcohol exchange reaction, and then highly crosslinked poly(furfuryl alcohol) (PFA), formed via thermal polymerization of FA, served as a temporary barrier to confine titania crystallization. The crystalline mesoporous titanias were finally obtained by removing PFA and organic surfactant. X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N2-sorption were used to characterize the crystalline mesoporous titanias. The characterizations showed that the crystalline mesoporous titanias prepared under different conditions possessed pore sizes of 11.1−23.6 nm and Brunauer−Emmett−Teller (BET) surface areas of 26.1−109.9 m2/g. The pore size and surface area of crystalline mesoporous titania increased when the ratio of titanium(IV) butoxide to furfuryl alcohol decreased. [ABSTRACT FROM AUTHOR]

The hydrothermal synthesis of ZnAPO-34 films supported on alumina substrates was reported in this paper. Synthesis parameters of the films were extensively examined. Organic content, water content, alumina source, and supports played important roles in the syntheses of ZnAPO-34 films. The best synthesis composition was found to be 0.4ZnO : 0.8Al2O3 : 1P2O5 : 2TEAOH : 225–550H2O with aluminum isopropoxide as alumina source. However, repeated syntheses were necessary to synthesize contineous ZnAPO-34 films on both nonporous an porous alumina supports. [ABSTRACT FROM AUTHOR]

Fast transport of monovalent ions is imperative in selective monovalent ion separation based on membranes. Here, we report the in situ growth of crown ether@UiO-66 membranes at a mild condition, where dibenzo-18-crown-6 (DB18C6) or dibenzo-15-crown-5 is perfectly confined in the UiO-66 cavity. Crown ether@UiO-66 membranes exhibit enhanced monovalent ion transport rates and mono-/divalent ion selectivity, due to the combination of size sieving and interaction screening effects toward the complete monovalent ion dehydration. Specifically, the DB18C6@UiO-66 membrane shows a permeation rate (e.g., K+) of 1.2 mol per square meter per hour and a mono-/ divalent ion selectivity (e.g., K+/Mg2+) of 57. Theoretical calculations and simulations illustrate that, presumably, ions are completely dehydrated while transporting through the DB18C6@UiO-66 cavity with a lower energy barrier than that of the UiO-66 cavity. This work provides a strategy to develop efficient ion separation membranes via integrating size sieving and interaction screening and to illuminate the effect of ion dehydration on fast ion transport. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) are superior ion adsorbents for selectively capturing toxic ions from water. Nevertheless, they have rarely been reported to have lithium selectivity over divalent cations due to the well-known flexibility of MOF framework and the similar physiochemical properties of Li+ and Mg2+. Herein, we report an ion-sieving adsorption approach to design sunlight-regenerable lithium adsorbents by subnanoporous MOFs for efficient lithium extraction. By integrating the ion-sieving agent of MOFs with light-responsive adsorption sites of polyspiropyran (PSP), the ion-sieving adsorption behaviors of PSP-MOFs with 6.0, 8.5, and 10.0 Å windows are inversely proportional to their pore size. The synthesized PSP-UiO-66 with a narrowest window size of 6.0 Å shows high LiCl adsorption capacity up to 10.17 mmol g−1 and good Li+ / Mg2+ selectivity of 5.8 to 29 in synthetic brines with Mg/Li ratio of 1 to 0.1. It could be quickly regenerated by sunlight irradiation in 6 min with excellent cycling performance of 99% after five cycles. This work sheds light on designing selective adsorbents using responsive subnanoporous materials for environmentally friendly and energy-efficient ion separation and purification. [ABSTRACT FROM AUTHOR]

Examines the synthesis of template-free zeolite nanocrystals by using in situ thermoreversible polymer hydrogels. Physical properties and thermogelation mechanism of zeolites; Schematic representations of synthesis of template-free zeolite nanocrystals.

The article presents a study which explores the ultrafast rectifying counter-directional transport of proton and metal ions in metal-organic framework–based nanochannels. It mentions that bioinspired control of ion transport at the subnanoscale has become a major focus in the fields of nanofluidics and membrane separation.

1D nanochannels modified with responsive molecules are fabricated to replicate gating functionalities of biological ion channels, but gating effects are usually weak because small molecular gates cannot efficiently block the large channels in the closed states. Now, 3D metal–organic framework (MOF) sub‐nanochannels (SNCs) confined with azobenzene (AZO) molecules achieve efficient light‐gating functionalities. The 3D MOFSNCs consisting of a MOF UiO66 with ca. 9–12 Å cavities connected by ca. 6 Å triangular windows work as angstrom‐scale ion channels, while confined AZO within the MOF cavities function as light‐driven molecular gates to efficiently regulate the ion flux. The AZO‐MOFSNCs show good cyclic gating performance and high on–off ratios up to 17.8, an order of magnitude higher than ratios observed in conventional 1D AZO‐modified nanochannels (1.3–1.5). This work provides a strategy to develop highly efficient switchable ion channels based on 3D porous MOFs and small responsive molecules. [ABSTRACT FROM AUTHOR]

The article offers information on use of ultrathin water-stable metal-organic framework membranes for ion separation. Topics discussed include exfoliation of two-dimensional (2D) monolayer aluminum tetra-(4-carboxyphenyl) porphyrin framework (termed Al-MOF) nanosheets; use of intrinsic nanopores of the Al-MOF nanosheets domain for ion/water separation; and long-term structural robustness in aqueous environment by exfoliated Al-MOF nanosheets.

The swelling properties of hydrogels as draw agents have been identified as one of the key parameters in determining the performance of polymer hydrogel-driven forward osmosis process. We report here a new strategy to improve the swelling property of hydrogels by the introduction of structural inhomogeneity and compressive forces in an ionic hydrogel for the purpose of increasing forward osmosis water flux. This is achieved by incorporating a hydrophobic, elastic polyester (PET) hollow microfiber into an ionic hydrogel under a compressive force during the preparation of the composite hydrogel monolith. The forward osmosis water flux of the composite hydrogels increased with increasing the microfiber loading and compression pressure. The composite hydrogel with 50 wt% PET microfiber loading and 18 kPa compression pressure demonstrated the highest flux. The water flux of poly(NIPAM-co-SA)-PET microfiber composite prepared under 18 kPa compression (PN5S5-PET-0.5/0.5-18) and poly(sodium acrylate)-PET microfiber composite (PSA-PET-0.5/0.5-18) reached 3.0 and 5.0 LMH in the first 10 min, respectively, when their swelling ratio is 4. The water flux of the composites was twice as high as the pure hydrogel. The composite hydrogels were also better at maintaining high water fluxes for a long period. The water flux of PSA-PET-0.5/0.5-18 decreased from 3.5 to 1.4 LMH after 24 h forward osmosis test. The combination of hydrophilic ionic hydrogel and hydrophobic PET microfiber resulted in an extended, porous structure within the hydrogel because of their different wettability, while an additional relaxation force was preserved in the composites because of the compression pressure applied during the preparation. Both of these worked together to enhance the FO water flux and maintain it for an extended long period. [ABSTRACT FROM AUTHOR]

Artificial nanochannels, inheriting smart gating functions of biological ion channels, promote the development of artificial functional nanofluidic devices for high-performance biosensing and electricity generation. However, gating states of the artificial nanochannels have been mainly realized through chemical modification of the channels with responsive molecules, and their gating states cannot be further regulated once the nanochannel is modified. In this work, we employed a new supramolecular layer-by-layer (LbL) self-assembly method to achieve reversible and adjustable multiple gating features in nanofluidic diodes. Initially, a self-assembly precursor was modified into a single conical nanochannel, then host molecule-cucurbit[8]uril (CB[8]) and guest molecule, a naphthalene derivative, were self-assembled onto the precursor through an LbL method driven by host-enhanced π-π interaction, forming supramolecular monolayer or multilayers on the inner surface of the channel. These self-assemblies with different layer numbers possessed remarkable charge effects and steric effects, exhibiting a capability to regulate the surface charge density and polarity, the effective diameter, and the geometric asymmetry of the single nanochannel, realizing reversible gating of the single nanochannel among multiple rectification and ion-conduction states. As an example of self-assembly of supramolecular networks in nanoconfinements, this work provides a new approach for enhancing functionalities of artificial nanochannels by LbL supramolecular self-assemblies. Meanwhile, since the host molecule, CB[8], used in this work can interact with different kinds of biomolecules and stimuli-responsive chemical species, this work can be further extended to build a novel stable multiple-state research platform for a variety of uses such as sensing and controllable release. [ABSTRACT FROM AUTHOR]

Herein, we report for the first time on the fabrication of a robust, thermoresponsive polymer membrane produced by the combination of an elastic polyurethane (TPU) microfiber web and poly(N-isopropylacrylamide) (PNIPAM). PNIPAM hydrogel is evenly coated on the surface of TPU microfibers, and thus, the wettability of TPU-PNIPAM membrane is amplified by taking advantage of the hierarchical structure and increased surface roughness. The TPU-PNIPAM membrane possesses switchable superhydrophilicity and superhydrophobicity as the temperature of membrane changes from 25 to 45 °C. The composite membrane is shown successfully able to separate a 1 wt % oil-in-water emulsion and 1 wt% water-in-oil emulsion at 25 and 45 °C, respectively, with a high separation efficiency of ≥99.26%. Furthermore, the composite membranes show excellent mechanical properties, and they are highly flexible and mechanically tough. The smart composite membranes reported here have shown great potential for further development for practical highefficiency oil--water separations. [ABSTRACT FROM AUTHOR]

Nanoporous titania nanoparticles(NTNs) were synthesized and usedas an additive at a low concentration of 0.1–1 wt % in thefabrication of poly(ethersulfone) (PES) ultrafiltration membranesvia non-solvent-induced phase separation. The structure and propertiesof nanoparticles were characterized using nitrogen sorption, X-raydiffraction, scanning electron microscopy, and transmission electronmicroscopy. The NTNs have a size distribution with a particle sizeof mainly <100 nm and have a Brunauer, Emmett, and Teller surfacearea of ∼100 m2g–1. The modifiedmembranes were fabricated and investigated in terms of their purewater flux, solute rejection, and fouling resistance. The water permeabilityand molecular weight cutoffs (MWCOs) of membranes were determinedunder constant-pressure filtration in dead-end mode at 100 kPa. Themembrane fouling resistance was characterized under constant fluxoperation using bovine serum albumin as a model foulant. The membraneswere characterized in terms of morphology, porosity, pore size distribution,energy-dispersive X-ray spectroscopy, contact angle goniometry, surfacefree energy, and viscosity of the dope solution. Overall, the modifiedmembrane showed increased wettability and reduced surface free energyand pore size. The modified UF membrane with 0.5 wt % NTN loadingexhibited improved fouling resistance (fouling rate of 0.58 kPa/mincompared to a rate of 0.70 kPa/min for the control membrane) with∼80% water flux recovery. The same membrane showed an ∼20%increase in water flux, an improvement in MWCO, and a narrower poresize distribution. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) were incorporated into alumina/polyethersulfone hollow fibre membranes to enhance the mechanical property and the efficiency of water treatment. Results show that the incorporation of CNTs can greatly limit the formation of large surface pores, decrease the void size in support layers and improve the porosity and pore connectivity of alumina/polyethersulfone membranes. As a result of such morphology change and pore size change, both improved flux and rejection were achieved in such CNTs/alumina/polyethersulfone membranes. Moreover, the CNTs/alumina/PES membranes show higher antifouling ability and the flux recoveries after being fouled by bovine serum albumin (BSA) and humic acid were improved by 84.1% and 53.2% compared to the samples without CNT incorporation. Besides the improvement in water treatment performance, the incorporation of CNTs enhanced the tensile properties of inorganic/polymer membranes. Therefore, such CNTs/alumina/PES hollow fiber membranes are very promising candidates for good filter media in industry, considering their high efficiency and high mechanical properties. [ABSTRACT FROM AUTHOR]

Tris(2,4,6-trimethoxyphenyl)polysulfonemethylenequaternary phosphoniumchloride (TPQP-Cl) was blended with polysulfone (PSf) in differentcompositions to fabricate PSf/TPQP-Cl composite ultrafiltration membranesusing the nonsolvent-induced phase separation method. The blendingof polymers was confirmed by attenuated total reflectance infrared(ATR-IR) spectroscopy. Surface and cross-sectional morphologies ofmembranes were characterized using scanning electron microscopy (SEM).The SEM images showed that the PSf/TPQP-Cl membranes had a typicalasymmetric structure. The X-ray photoelectron spectroscopy (XPS) andcontact angle analysis revealed the enrichment of TPQP-Cl in the supportinglayer of the membrane. In addition, water content, porosity, contactangle, pure water flux, and molecular weight cutoff were measuredto study the influence of addition of TPQP-Cl. In particular, theaddition of TPQP-Cl led to greatly increased water flux without significantlyincreased molecular weight cutoff; the PSf/TPQP-Cl membranes exhibitedup to 7.3 times higher water flux than the pure PSf membrane at similarrejection properties. This work provides an effective way to tailorultrafiltration membrane structure to achieve high flux while maintainingrejection properties. [ABSTRACT FROM AUTHOR]

Salinity difference between seawater and river water is a sustainable energy resource that catches eyes of the public and the investors in the background of energy crisis. To capture this energy, interdisciplinary efforts from chemistry, materials science, environmental science, and nanotechnology have been made to create efficient and economically viable energy conversion methods and materials. Beyond conventional membrane-based processes, technological breakthroughs in harvesting salinity gradient power from natural waters are expected to emerge from the novel fluidic transport phenomena on the nanoscale. A major challenge toward real-world applications is to extrapolate existing single-channel devices to macroscopic materials. Here, we report a membrane-scale nanofluidic device with asymmetric structure, chemical composition, and surface charge polarity, termed ionic diode membrane (IDM), for harvesting electric power from salinity gradient. The IDM comprises heterojunctions between mesoporous carbon (pore size ~7 nm, negatively charged) and macroporous alumina (pore size ~80 nm, positively charged). The meso-/macroporous membrane rectifies the ionic current with distinctly high ratio of ca. 450 and keeps on rectifying in high-concentration electrolytes, even in saturated solution. The selective and rectified ion transport furthermore sheds light on salinity-gradient power generation. By mixing artificial seawater and river water through the IDM, substantially high power density of up to 3.46 W/m2 is discovered, which largely outperforms some commercial ion-exchange membranes. A theoretical model based on coupled Poisson and Nernst—Planck equations is established to quantitatively explain the experimental observations and get insights into the underlying mechanism. The macroscopic and asymmetric nanofluidic structure anticipates wide potentials for sustainable power generation, water purification, and desalination. [ABSTRACT FROM AUTHOR]

The novel oriented electrospun nanofiber membrane composed of MOFs and SPPESK has been synthesized for proton exchange membrane fuel cell operating at high temperature and anhydrous conditions. It is clear that the oriented nanofiber membrane displays the higher proton conductivity than that of the disordered nanofiber membrane or the membrane prepared by conventional solvent-casting method (without nanofibers). Nanofibers within the membranes are significantly oriented. The proton conductivity of the oriented nanofiber membrane can reach up to (8.2 ± 0.16) × 10-2 S cm-1 at 160°C under anhydrous condition for the highly orientation of nanofibers. Moreover, the oxidative stability and resistance of methanol permeability of the nanofibers membrane are obviously improved with an increase in orientation of nanofibers. The observed methanol permeability of 0.707 × 10-7 cm2 s-1 is about 6% of Nafion-115. Consequently, orientated nanofibers membrane is proved to be a promising material as the proton exchange membrane for potential application in direct methanol fuel cells. [ABSTRACT FROM AUTHOR]

The feasibility of bilayer polymer hydrogels as draw agent in forward osmosis process has been investigated. The dual-functionality hydrogels consist of a water-absorptive layer (particles of a copolymer of sodium acrylate and N-isopropylacrylamide) to provide osmotic pressure, and a dewatering layer (particles of N-isopropylacrylamide) to allow the ready release of the water absorbed during the FO drawing process at lower critical solution temperature (32 °C). The use of solar concentrated energy as the source of heat resulted in a significant increase in the dewatering rate as the temperature of dewatering layer increased to its LSCT more rapidly. Dewatering flux rose from 10 to 25 LMH when the solar concentrator increased the input energy from 0.5 to 2 kW/m2. Thermodynamic analysis was also performed to find out the minimum energy requirement of such a bilayer hydrogel-driven FO process. This study represents a significant step forward toward the commercial implementation of hydrogel-driven FO system for continuous production of fresh water from saline water or wastewaters. [ABSTRACT FROM AUTHOR]

Freshwater shortage is one of the most pressing global issues. Forward osmosis (FO) desalination technology is emerging for freshwater production from saline water, which is potentially more energy-efficient than the current reverse osmosis process. However, the lack of a suitable draw solute is the major hurdle for commercial implementation of the FO desalination technology. We have previously reported that thermoresponsive hydrogels can be used as the draw agent for a FO process, and this new hydrogel-driven FO process holds promise for further development for practical application. In the present work, magnetic field-induced heating is explored for the purpose of developing a more effective way to recover water from swollen hydrogel draw agents. The composite hydrogel particles are prepared by copolymerization of sodium acrylate and N-isopropylacrylamide in the presence of magnetic nanoparticles (γ-Fe2O3, <50 nm). The results indicate that the magnetic heating is an effective and rapid method for dewatering of hydrogels by generating the heat more uniformly throughout the draw agent particles, and thus, a dense skin layer commonly formed via conventional heating from the outside of the particle is minimized. The FO dewatering performance is affected by the loading of magnetic nanoparticles and magnetic field intensity. Significantly enhanced liquid water recovery (53%) is achieved under magnetic heating, as opposed to only around 7% liquid water recovery obtained via convection heating. Our study shows that the magnetic heating is an attractive alternative stimulus for the extraction of highly desirable liquid water from the draw agent in the polymer hydrogel-driven forward osmosis process. [ABSTRACT FROM AUTHOR]

Mesoporous silica-carbon nanocomposites (C-SiO2) were synthesized for the fabrication of highly crystalline silicon carbide (SiC) nanoparticles and nanofibers via carbothermal reduction. SiC nuclei were introduced into the mesopores as seeds by infiltration of preceramic precursor polycarbosilane (PCS) prior to the heat treatment of carbothermal reduction. When PCS with a mass percentage of 11-13% was infiltrated into the mesoporous C-SiO2, SiC nanofibers and nanoparticles were produced at 1450 °C, even in the sample with low carbon content. The major morphology formed from the mesoporous C-SiO2 nanocomposites without PCS infiltration was nanoparticles, while nanofibers dominated in the products of PCS-infiltrated compositions. The results indicate that the conversion of PCS into SiC nuclei in mesopores prior to carbothermal reduction has facilitated the formation of SiC nanofibers. Therefore infiltration of seeds into mesopores of C-SiO2 precursors appears to be an effective means of accelerating the reaction and controlling SiC nanostructures. [ABSTRACT FROM AUTHOR]

Lanthanum phosphate (LaPO4) nanostructures with different morphologies were prepared by a facile solution–precipitation process. The effect of different reaction conditions on the morphology of nanostructures was studied. When the molar ratio of La3+ : H3PO4was around 1 : 2, 1 : 20, 1 : 100, and 1 : 200, four different morphologies, such as near-spherical, snowflake-like, star-shaped, lens-like nanostructures and short nanorods, were obtained, respectively. Meanwhile, similar shapes developed when the molar ratio of H3PO4to ionic surfactants, such as SDS and CTAB, was varied. In addition, Eu3+doped and Ce3+/Tb3+co-doped LaPO4nanostructures showed morphology evolution similar to undoped LaPO4nanostructures. The optical properties of these doped LaPO4were also characterized. [ABSTRACT FROM AUTHOR]

Aluminophosphates molecular sieves AlPO4-5 with novel morphologies of brooms and nano-fibers (∼3.8 µm and 70–200 nm in width, respectively) were hydrothermally synthesized by varying the precursor compositions, and used as templates to prepare hexagonal carbon micro and submicro tubes. [ABSTRACT FROM AUTHOR]

Traditional ceramic separation membranes, which are fabricated by applying colloidal suspensions of metal hydroxides to porous supports, tend to suffer from pinholes and cracks that seriously affect their quality. Other intrinsic problems for these membranes include dramatic losses of flux when the pore sizes are reduced to enhance selectivity and dead-end pores that make no contribution to filtration. In this work, we propose a new strategy for addressing these problems by constructing a hierarchically structured separation layer on a porous substrate using large titanate nanofibers and smaller boehmite nanofibers. The nanofibers are able to divide large voids into smaller ones without forming dead-end pores and with the minimum reduction of the total void volume. The separation layer of nanofibers has a porosity of over 70% of its volume, whereas the separation layer in conventional ceramic membranes has a porosity below 36% and inevitably includes dead-end pores that make no contribution to the flux. This radical change in membrane texture greatly enhances membrane performance. The resulting membranes were able to filter out 95.3% of 60-nm particles from a 0.01 wt % latex while maintaining a relatively high flux of between 800 and 1000 L/m2·h, under a low driving pressure (20 kPa). Such flow rates are orders of magnitude greater than those of conventional membranes with equal selectivity. Moreover, the flux was stable at approximately 800 L/m2·h with a selectivity of more than 95%, even after six repeated runs of filtration and calcination. Use of different supports, either porous glass or porous alumina, had no substantial effect on the performance of the membranes; thus, it is possible to construct the membranes from a variety of supports without compromising functionality. The Darcy equation satisfactorily describes the correlation between the filtration flux and the structural parameters of the new membranes. The assembly of nanofiber meshes to combine high flux with excellent selectivity is an exciting new direction in membrane fabrication. [ABSTRACT FROM AUTHOR]

A facile dual-templating approach is demonstrated to prepare hierarchically ordered macro-/mesoporous carbons. Monodispersed silica colloidal crystals are used as a hard template, amphiphilic triblock copolymer PEO−PPO−PEO as a soft template, and soluble resols as a carbon source. The procedure involves packing and aging of silica microspheres, evaporation-induced organic−organic assembly of mesostructures in the void of microspheres, thermosetting and carbonization of phenolic formaldehyde (PF), and removal of silica scaffolds by HF. The obtained porous carbons have a highly ordered face-centered cubic macrostructure with tunable pore sizes of 230−430 nm and interconnected windows with a size of 30−65 nm. The rigid silica hard templates can prevent the shrinkage of the mesostructure during the thermosetting and carbonization process, resulting in large cell parameters (∼18 nm) and pore sizes (∼11 nm). The bimodal porous carbon materials have large BET surface areas (up to 760 m2/g), large pore volumes (∼1.25 cm3/g), and partially graphitized frameworks. With the increase in the silica sphere diameter, the BET surface areas and the window sizes increase. The hierarchically ordered carbon structures show strong diffraction at wavelengths of 500−690 nm depending on the treatment used. [ABSTRACT FROM AUTHOR]

A mesoporous carbon structure was template-synthesized from small nanoparticles of silica with internal M41S type mesopores. The silica template was synthesized according to Suzuki et al. using an ionic surfactant to create the internal mesopores 1.8−3.5 nm diameter and a nonionic surfactant to limit the overall size of the particle. Larger mesopores in the silica are needed for carbonization to a better structure. This was achieved by the use of a swelling agent, trimethylbenzene (TMB). Characterization by transmission electron microscopy (TEM), X-ray diffraction (XRD), and nitrogen sorption analysis showed a mesocellular foamlike carbon structure composed of porous cells with internal hexagonally arranged channels. In addition to the 3 nm internal channels, there were larger mesopores connecting the cellular domains. These larger mesopores were formed in the interparticle voids created during carbonization. The dual porosity network structure had a high surface area (>1000 m2/g) and large pore volume (>1.2 mL/g). When loaded with Pt−Ru nanoparticles, the PtRu/carbon became a good electrocatalyst and gave the highest activity for methanol oxidation among several PtRu electrocatalysts including commercial electrocatalysts. [ABSTRACT FROM AUTHOR]

ZIF-8 films were successfully prepared on a flexible nylon substrate with a contra-diffusion synthesis method, and gas permeation experiments indicated that the films were continuous and compact. [ABSTRACT FROM AUTHOR]

Porous Pt nanowire arrays show enhanced electrocatalytic activities for ethanol oxidation in direct alcohol fuel cells. [ABSTRACT FROM AUTHOR]

Porous Pt nanowire arrays show enhanced electrocatalytic activities for ethanol oxidation in direct alcohol fuel cells. [ABSTRACT FROM AUTHOR]

A novel combustion synthesis of ceramic powder has been developed using humic acids (HA) as the complexible fuel. Synthesis of mixed oxide (Sm0.5Sr0.5CoO3 (SSC)) ceramic nanoparticles was chosen to illustrate synthetic procedures. SSC nanoparticles obtained by combustion of HA–metal complexes exhibited particle sizes of 50–100 nm, and good electrochemical performance as the cathode material for solid oxide fuel cells. The process of using renewable HA as the complexible fuel is of low cost, and thus suitable for sustainable production of various oxide ceramic materials. [ABSTRACT FROM AUTHOR]