Luminescence Changeable CO-Storage Cylinder: Triple-Stranded Helical Eu(III)/Tb(III) Fluorinated MOFs with Amide Linkers.

Triple-stranded helical lanthanide MOFs with CO adsorption properties were investigated. Lanthanide MOFs ([EuTb(hfa)(dpa)]) are composed of lanthanide luminophores (Eu(III) and/or Tb(III) ions), fluorinated antenna ligands (hfa: hexafluoroacetylacetonate), and polyamide-type linker ligands (dpa: 4-(diphenylphosphoryl)-N-(4-(diphenylphosphoryl)phenyl)benzamide). The cylindrical structure was characterized by single-crystal X-ray analysis, thermogravimetric analysis, and gas adsorption measurements.

Improving porous properties of activated carbon from carbon gel by the OTA method.

High-surface-area microporous-mesoporous carbons were produced from carbon gel by applying the three consecutive steps of air oxidation, thermal treatment, and activation (the OTA method) to the gel. The formation of mesopores occurs both inside and outside the nanoparticles which form the carbon gel, while micropores are predominantly created within the nanoparticles. The OTA method offered a greater increase in pore volume and BET surface area of the resulting activated carbon in comparison with conventional CO activation either under the same activation conditions or at the same degree of carbon burn-off.

Development of an efficient CVD technique to prepare TiO/porous-carbon nanocomposites for high rate lithium-ion capacitors.

Titanium dioxide is a promising electrode material for lithium-ion capacitors. When using TiO as an electrode material, it is necessary to combine it with carbon at the nanometer level to improve its low electrical conductivity and low reactivity with Li. However, preparation methods of reported TiO/porous-carbon nanocomposites are generally not cost-effective, and their productivities are low.

Synthesis of Mg-Al Mixed Oxides with Markedly High Surface Areas from Layered Double Hydroxides with Organic Sulfonates.

Mg-Al mixed oxides with record-high surface areas and basic site concentrations were synthesized from Mg-Al layered double hydroxides with interlayer isethionate (Ise) or 3-hydroxy-1-propanesulfonate (HPS). Anion exchange of interlayer CO in synthetic hydrotalcites with the organic sulfonates induces disorders in layer stacking as characterized by powder X-ray diffraction and enables facile delamination in water. Thermal treatment of materials anion-exchanged by Ise (MgAl-Ise) and HPS (MgAl-HPS) in N and H resulted in the formation of Mg-Al mixed oxides with marked enhancement in Brunauer-Emmett-Teller (BET) surface area relative to those treated in air.

Development of TiO-SiO Photocatalysts Having a Microhoneycomb Structure by the Ice Templating Method.

Immobilization of TiO-based photocatalysts usually suffers from lowered surface area and mass transfer limitation compared with their suspended counterpart. In this work, TiO-SiO monolithic photocatalysts having straight macropores, called microhoneycombs, were synthesized. The obtained samples had straight macropores with a diameter in the range of 15-40 μm formed by walls having a thickness up to 5 μm.

Carbon Paper with a High Surface Area Prepared from Carbon Nanofibers Obtained through the Liquid Pulse Injection Technique.

To improve the performance of carbon paper used for applications such as electrodes for electrochemical devices and air filters, two types of long carbon nanofibers (CNFs) with average diameters of 20 and 49 nm were prepared by the liquid pulse injection (LPI) technique by adjusting reaction conditions. Carbon paper was made from the CNFs through a simple filtration process. The paper prepared from the CNFs with an average diameter of 20 nm (LPI-CNF(20) paper) was firm and flexible even though it was prepared without using any binders.

Immobilization of magnesium ammonium phosphate crystals within microchannels for efficient ammonia removal.

Magnesium ammonium phosphate was formed in flow-through microchannels of silica monoliths using two different methods to fabricate materials that show efficient ammonia adsorption performance from wastewater with low hydraulic resistance. Magnesium ammonium phosphate crystals in these materials release ammonia when heated at 378 K, yielding primarily magnesium hydrogen phosphate. When this material was used for ammonia removal from an aqueous solution containing 100 ppm ammonia in a flow system, the material readily removed ammonia, decreasing the ammonia concentration to 25 ppm.

Dynamic and static light scattering study on the sol-gel transition of resorcinol-formaldehyde aqueous solution.

Structure formation during the sol-gel transition of resorcinol-formaldehyde (RF) solutions was traced by dynamic light scattering (DLS) and static light scattering (SLS) techniques. The decay time spectra obtained by DLS revealed that both the growth rates of colloidal particles formed during the early stage of the sol-gel transition and the time required for the colloidal particles to form a firm network structure could be related to the ratio of catalyst to water (C/W) of the starting RF solution. SLS results indicated that the molecular weight of colloidal particles increased with the progress of the sol-gel transition, the rate of which was also affected by the value of C/W.

Interpretation of structure formation during the sol-gel transition of a resorcinol-formaldehyde solution by population balance.

Growth of colloidal particles formed during the sol-gel transition of a resorcinol-formaldehyde (RF) solution was simulated based on the population balance equation by using the discrete-sectional model (DSM). During the early stage of the sol-gel transition, the transient change of sizes of colloidal particles estimated by this method agreed well with the previous experimental observation by dynamic light scattering (DLS), which confirmed the influence of the catalyst concentration of a starting RF solution on the growth rate of the particles. From the size distribution of colloidal particles predicted at the gelation time, the surface area of a RF hydrogel after the completion of the sol-gel transition was estimated, which coincided with the BET surface area of a RF aerogel because the porous structure of a hydrogel was maintained and few micropores were formed during supercritical drying.

Formation of monolithic silica gel microhoneycombs (SMHs) using pseudosteady state growth of microstructural ice crystals.

Monolithic silica gel microhoneycombs, which have an array of straight macropores within their structure and developed micro/mesopores inside their walls, were prepared using pseudosteady state growth of ice crystals which occurs during the unidirectional freeze-gelation of freshly gelled aqueous silica hydrogels, followed by a pore-protecting drying method, freeze drying.

Adsorption of phenol and reactive dye from aqueous solution on activated carbons derived from solid wastes.

Activated carbons were produced from several solid wastes, namely, waste PET, waste tires, refuse derived fuel and wastes generated during lactic acid fermentation from garbage. Activated carbons having various pore size distributions were obtained by the conventional steam-activation method and via the pre-treatment method (i.e.