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Capturing and analyzing cometary coma dust lead to elucidate the origin of water and organics within the Solar System. For future sample return missions of fragile organic microparticles from a cometary nucleus, rendezvous operations will become more favorable than flyby missions because the comet rendezvous can reduce impacting velocity of cometary dust particles slow enough to capture them intact, rather than hypervelocity flyby sampling like the Stardust mission to the Comet Wild 2. At JAXA/ISAS, we are developing a core technology for sample return of microparticles ejected at as a lower velocity as an order of 0.1 m/s to 100 m/s after rendezvous with a cometary nucleus. We have devised “Vertically Aligned Carbon Nanotube (VA-CNT)” carpets as an effective capture medium for such a purpose. The VA-CNT carpets can amplify van der Waals force with impacting particles due to the large contact area and can capture intact the microparticles of sub-mm in size or smaller in the vacuum space environment while preserving its adhesive strength. In this study, we modelled capturing mechanism of microparticles on the VA-CNT carpets by the impact analysis software “LS-DYNA” to further improve its particle capture performance. The stress-strain constitutive laws for the VA-CNT carpets were derived via indentation and inputted to our simulations that were consistent with impact experiment results. The simulations reveal that the mechanical property of the VA-CNT carpets is the key for the improvement of its particle capture performance suitable for sampling the cometary dust.

Clathrate hydrate as well as ice has been spotlighted as promising materials to investigate the properties of hydrogen-bonded networks formed by the water molecules. In the semiclathrate hydrate (SCH, a kind of clathrate hydrate) consisting of host water molecules and guest quaternary onium salts, the anion takes part in the hydrogen-bonded networks with the water molecules. In the present study, we measured the electrical conductivity and electrical relaxation time in the single-crystalline tetra-n-butylammonium bromide (TBAB) SCH by electrochemical impedance spectroscopy. The results clearly revealed that the conduction carrier was proton. The electrical relaxation time of proton conduction in TBAB SCH was similar to the reorientation time of the water molecules in TBAB SCH estimated by the results of nuclear magnetic resonance.

Phase equilibrium (temperature–composition) relations of the tetra-n-butylphosphonium trifluoroacetate (TBP-TFA) + water binary system including solid (semiclathrate hydrate, SCH)-liquid equilibria and liquid-liquid equilibria were investigated. Phase diagram of TBP-TFA SCH exhibited peritectic behavior. The maximum decomposition temperature (peritectic temperature) of TBP-TFA SCH at atmospheric pressure were 275.9 ± 0.1 K. The stoichiometric composition of TBP-TFA SCH was located at the mole fraction of 0.027 ± 0.002. The decomposition enthalpy of TBP-TFA SCH was 199 ± 2 J/g. At temperatures above the lower critical solution temperature (LCST), the liquid-liquid phase separation appeared. Interestingly, the composition at the LCST was 0.026 ± 0.002, which is very similar to the stoichiometric composition of TBP-TFA SCH. It implies that both cluster-based solution structures are similar.

Impact-cratering processes on small bodies are thought to be mainly controlled by the local material strength because of their low surface gravity, and craters that are as large as the parent bodies should be affected by the target curvature. Although cratering processes on planar surfaces in the strength-controlled regime have been studied extensively, the mechanism by which target curvature affects the cratering processes remains unclear. Herein, we report on a series of impact experiments that used spherical targets with various diameters. The resultant craters consisted of a deep circular pit and an irregular-shaped spall region around the pit, which is consistent with the features reported in a number of previous cratering experiments on planar surfaces. However, the volume and radius of the craters increased with the normalized curvature. The results indicate that the increase in the spall-region volume and radius mainly contributes to the increase in the whole crater volume and radius, although the volume, depth, and radius of pits remain constant with curvature. The results of our model indicate that the geometric effect due to curvature (i.e., whereby the distance from the equivalent center to the target free surface is shorter for higher curvature values) contributes to increases in the cratering efficiency. Our results suggest that the impactors that produce the largest craters (basins) on some asteroids are thus smaller than what is estimated by current scaling laws, which do not take into account the curvature effects., Accepted for publication in Icarus, 37 pages, 9 figures, 2 tables

Transparent glass fiber composites were prepared with a refractive-index-adjustable thermoplastic blend. The opacity of a polymer blend is affected by the phase separation and crystallization properties. Polyamide 6 (PA6)/poly (m-xylene adipamide) (MXD6) blends are intrinsically miscible and transparent in the molten state; further, crystallization is suppressed by polymer chain disordering induced by in-situ transamidation. Thus, the transparency of the molten state was maintained after a sufficient period of melt-mixing. The refractive index was adjusted to that of the glass fiber reinforcement by altering the PA6/MXD6 blend ratio. Injection-molded glass fiber composites of PA6/MXD6 had good transparency and mechanical properties.

Carbon fiber reinforced thermoplastics (CFRTPs) with superior mechanical properties and hygrothermal resistance were fabricated using a strategically designed ternary polymer blend of polyamide 6 (PA6), polyethylene terephthalate (PET), and phenol novolac (PN). The polymer blend was designed to improve the hygrothermal stability of PA6 while retaining good adhesivity to carbon fiber. The miscible and immiscible components in the blend (PN and PET, respectively) have different contributions that act cooperatively to improve the hygrothermal resistance of PA6. The interfacial strength between the ternary polymer blend and carbon fiber is as high as that for PA6 because all components in the polymer matrix include polar functional groups. CFRTPs having the ternary blend as the polymer matrix exhibit superior stiffness under hygrothermal conditions than a conventional PA6-matrix CFRTP.

A naphthalimide–dicyanoisophorone conjugate (1) was synthesized and used as a chemodosimeter for fluorometric and colorimetric detection of hypochlorous acid (HClO) and hypochlorite (OCl–) in aqueous media. This molecule shows a strong reddish-purple color and a weak fluorescence, but HClO/OCl–-selective oxidative decomposition of the dicyanoisophorone moiety promotes a color fading and a fluorescence enhancement. Ab initio calculation revealed that these responses to HClO/OCl– originate from the suppression of intramolecular electron transfer from the photoexcited naphthalimide moiety by the decomposition of the dicyanoisophorone moiety. These colorimetric and fluorometric responses facilitate relatively rapid (∼5 min), selective, and sensitive detection of HClO/OCl– as low as ∼1.3 μM under physiological conditions.

We conducted four sets of impact experiments using sedimentary rock targets and three different kinds of projectiles at a variety of impact angles in order to examine how the density of a projectile affects the dimensions of a crater as the angle of impact decreases, the threshold angle for the formation of elliptical craters, and the threshold angle for the formation of pits. The crater profiles, crater volume, equivalent diameter, length, width, depth, and ellipticity of each set were carefully measured to be used in comparison with small craters that formed on the weak rocky surfaces of planetary bodies. The results indicate that the crater volume, equivalent diameter, width, and depth decrease with the impact angle, while the length of the crater within a set does not decrease monotonically with impact angle. This trend in crater length is consistent with the results of previous studies. Although craters formed at higher impact angles have a central pit, the pit becomes unclear and eventually disappears as the impact angle decreases. A larger threshold angle is required for the formation of pits at slower impact velocity than at higher impact velocity. Our results suggest that the presence of a central pit is indicative of impacts at higher angles and/or higher velocity. The ratio of the volume of craters resulting from oblique impacts to that of craters formed by normal impacts was proportional to the power of the sine of the impact angle. The power index was found to range between 1.46 and 2.20, with an average of 1.57. Comparison of the averaged power index to the power index of the π-group crater scaling rules, it is experimentally suggested that the hypothesis indicating that the vertical velocity component controls crater formation is plausible on a brittle target. The threshold angles for the formation of elliptical craters for three different kind of projectiles were almost consistent with those obtained in previous studies. Our results strongly suggested that the threshold angle for the formation of elliptical craters for high-density impactor, such as iron meteorites, are higher than for rocky impactors. We then obtained a relationship between the threshold angle for the formation of pits and the cratering efficiency. It is revealed that the threshold angle for the formation of pits is greater than the threshold angle for the formation of elliptical craters, when the cratering efficiency is in the range 7–30. A well-developed pit-spall structure in the crater may be used to indicate both, the impact angle and the vertical component of the impact velocity.

We investigated the design of relatively large cyclones with large amounts of airflow containing dust that are used in actual dust collection plants. In order to obtain basic data on the design of conical cyclones with a Reynolds number of approximately 8.9 × 105, we compared the fluid analysis results with the experimental results on dust collection and particle classification performance for conical cyclones to which apex cones and stabilizers were attached. Then, we elucidated the relationship between the flow conditions inside the conical cyclone with a Reynolds number of 8.9 × 105 and dust collection and particle classification performance.

Accepted: 2014-05-12, 資料番号: SA1140138000

Fully bio-based polyamide 11 (PA11) and poly(vinylcatechol) (PVCa) blends prepared by melt mixing demonstrate thermodynamic miscibility and excellent engineering properties. The glass transition temperature (Tg) of PA11 increases upon blending with PVCa; an 85/15 wt% PA11/PVCa blend exhibits a Tg 23–26 °C higher than that of PA11 devoid of additives. Morphological observations revealed that the PA11/PVCa blends do not phase-separate, confirming the homogeneity of PA11 and PVCa. Good chemical resistance of the PA11/PVCa blends was confirmed, with the blends resisting morphological changes even after immersion in methanol, which is a good solvent for PVCa. Tensile testing revealed that the PA11/PVCa blends have higher moduli and strengths than PA11. A PA11/nonpolar polystyrene blend was also examined by the same experimental procedure, which revealed that strong hydrogen bonding between PA11 and PVCa is the primary reason for the miscibility and excellent performance of PA11/PVCa blends.

A fluorescein–spiropyran conjugate (2) behaves as a receptor for colorimetric sensing of cyanide anion (CN−) in aqueous media under irradiation of UV light. The compound 2, which exists as a spirocycle-closed (SP) form in the dark condition, is isomerized to the spirocycle-opened merocyanine (MC) form upon irradiation of UV light and shows absorption bands at 467 and 568 nm. Addition of CN− to the solution leads to a decrease in these bands and an appearance of new absorption band at 512 nm, via a nucleophilic interaction between CN− and the spirocarbon of MC form. This absorption change occurs selectively with CN− and enables ratiometric quantification of CN− by absorption analysis.

A benzoxadiazole–thiourea conjugate ( 1 ) was synthesized and used for chemodosimetric detection of Hg 2+ in aqueous media. The compound 1 shows a selective and quantitative fluorescence quenching upon addition of Hg 2+ . This is promoted via a Hg 2+ -induced desulfurization of the thiourea moiety, leading to a formation of an imidazoline derivative, 2 . Ab initio molecular orbital calculation reveals that the formation of imidazoline moiety by the reaction of 1 with Hg 2+ promotes a photoinduced electron transfer from the aniline moiety to the excited state benzoxadiazole moiety and results in fluorescence quenching.

A spiropyran derivative containing a dinitrophenolate moiety ( 2 : 1′,3′,3′-trimethyl-6,8-dinitro-spiro-[2 H -1-benzopyran-2,2′-indoline]) behaves as a receptor for selective detection of cyanide anion (CN − ) in aqueous media. Compound 2 , when dissolved in aqueous media, spontaneously produces the spirocycle-opened merocyanine (MC) form even in dark condition. The absorption band of the MC form decreases selectively upon addition of CN − , via a nucleophilic addition of CN − to the spirocarbon of the MC form. The nucleophilic addition occurs very rapidly (within 1 min) and enables rapid and selective quantification of very low levels of CN − (>0.8 μM) by an absorption analysis.

We previously found that a simple spiropyran derivative (1:1′,3′,3′-trimethyl-6-nitro-spiro-[2H-1-benzopyran-2,2′-indoline]) behaves as a selective and sensitive cyanide anion (CN−) receptor in aqueous media under UV irradiation 13 . The receptor, when irradiated by UV light in a water/MeCN mixture, creates a CN−-selective absorption band via a nucleophilic addition of CN− to 1 (formation of the 1–CN− species) and allows quantitative determination of very low levels of CN−. In the present work, effects of pH and water content on the response of 1 to anions were studied to clarify the detailed properties of 1. In aqueous media, 1 reacts selectively with CN−regardless of pH and water content, but the reaction is suppressed by a decrease in pH and an increase in water content due to the protonation of CN−. In contrast, in pure MeCN, addition of F− also creates a new absorption band, as does CN−. This is promoted via a nucleophilic interaction between 1 and F− in a 1:2 stoichiometry (formation of the 1–2F− species). The 1–CN− and 1–2F− species have different photochemical properties; the 1–CN− species is stable upon UV irradiation, while the UV irradiation of the 1–2F− species leads to a decomposition of the spiropyran platform.

A new bis-quinolylimine ligand containing an azadiene moiety, 1,4-bis(2-quinolyl)-2,3-diaza-1,3-buthadiene (1), was synthesized by one-step facile condensation. This simple ligand, when dissolved in acetonitrile, shows a Cu2+-selective fluorescence enhancement. Coordination of 1 with Cu2+ produces two kinds of complexes with 1:1 and 1:2 stoichiometries. The 1:2 complex shows a strong fluorescence (ΦF = 0.37), while the 1:1 complex does not (ΦF

Fluorescence properties of polyamines bearing two terminal quinoline fragments with different polyamine chain length, such as ethylenediamine ( L0 ), diethylenetriamine ( L1 ), and triethylenetetramine ( L2 ), have been studied in water. These ligands show Zn 2+ -induced fluorescence enhancement, while showing almost no enhancement with other cations. However, stability constants for Zn 2+ coordination and fluorescence response against Zn 2+ depend strongly on the polyamine chain length. The chain length also affects the fluorescence wavelength. The Zn 2+ – L1 and Zn 2+ – L2 complexes show emission at 410 nm, while Zn 2+ – L0 complexes show a blue-shifted emission at 375 nm due to the partial charge transfer from the excited state quinoline to the Zn 2+ center.

Two kinds of amphiphilic graft copolymers, PAA-g-P(MMA-co-BP) and P(AA-co-BP)-g-PMMA, consisting of polar poly(acrylic acid) (PAA), less polar poly(methyl methacrylate) (PMMA), and benzophenone (BP) photosensitizing units, have been synthesized. These polymers, when used as a photosensitizer for isomerization of trans-β-methylstyrene, show a sensitization activity controlled by solvents. In benzene and chloroform, P(AA-co-BP)-g-PMMA forms a micelle structure consisting of aggregated P(AA-co-BP) core with dissolved PMMA units at the outer sphere. This suppresses a triplet energy transfer (TET) from the excited state BP units to olefin and, hence, shows lower sensitization activity than a bulk sensitizer (4-methoxybenzophenone: MBP). In methanol, both polymers form a weak aggregate of less polar PMMA units containing dissolved PAA units. The internal cavity of the aggregate is less polar and stabilizes the excited state BP units. This accelerates a TET from the excited state BP units to olefin and shows higher sensitization activity than MBP.

A new boradiazaindacene (BODIPY) derivative (1a) bearing simple NO bidentate ligands has been synthesized. The 1a molecule behaves as a fluorescent probe for Cr3+ and shows strong red fluorescence upon coordination with Cr3+, while showing almost no fluorescence for other metal cations.

Cross-linked polymer nanocapsules (PC) encapsulating an iron tris(bipyridine) complex, Fe(bpy)32+@PC, have been synthesized by a ship-in-a-bottle method. This was used as a photosensitizer for the decomposition of organic pollutant in water under visible light irradiation with molecular oxygen. The Fe(bpy)32+@PC promotes efficient decomposition of organic pollutant, whereas noncapsulated Fe(bpy)32+ is inactive. The enhanced sensitization activity of Fe(bpy)32+ within PC is due to the interaction with the PC wall. This lengthens the lifetime of the excited state Fe(bpy)32+ and promotes efficient production of hydroxyl radicals. The sensitization activity of Fe(bpy)32+@PC depends on the thickness of the PC wall. The Fe(bpy)32+@PC with an appropriate PC wall thickness allows accumulation of pollutant within the PC and, hence, promotes efficient decomposition of pollutant.

This paper proposes a functionally graded Pd/γ-alumina composite membrane fabricated by a novel method for electroless plating by combining supercritical fluid technology and Pd electroless plating in a hybrid technique. The electroless plating reactions on catalyzed nanoporous γ-alumina surfaces were carried out in an emulsion of supercritical carbon dioxide (sc-CO 2 ) and an electroless plating solution with fluorinated surfactant F(CF(CH 3 )CF 2 O) 3 CF(CF 3 )COO(CH 2 CH 2 O)CH 3 . Pd/γ-alumina graded membrane produced by electroless plating with sc-CO 2 had thicker Pd/γ-alumina graded layer and smoother surface than conventional electroless plating. In electroless plating with sc-CO 2 , the penetration into the nanoporous γ-alumina pores was dominant reaction because the deposited Pd particles were smaller and, moreover, the electroless plating media with dispersed CO 2 has lower viscosity than conventional electroless plating. The Pd membrane formed in the emulsion of sc-CO 2 was about 1 μm thickness and composed of a composite membrane of 0.45 mol m −2 min −1 as hydrogen flux, while 0.30 mol m −2 min −1 of the Pd membrane formed by conventional electroless plating.

A BODIPY–indole conjugate, 1, behaves as a colorimetric and fluorometric probe for selective and sensitive detection of F−. Compound 1 interacts with F− in a 1:1 stoichiometry via a hydrogen bonding interaction between the indolic NH proton and F−, leading to clear color change from blue to green and quenching of orange fluorescence.

Fluorescence properties of rhodamine–diacetic acid conjugates ( 1a – e ), with different alkyl chain length (C2–C6) between the rhodamine and the diacetic acid moieties, have been studied in the presence of Cu 2+ and Hg 2+ . Without cations or with other cations, these probes show almost no fluorescence; however, addition of Cu 2+ creates strong green fluorescence at around 530 nm, while Hg 2+ addition shows weak orange fluorescence at around 580 nm. The Cu 2+ -induced green fluorescence originates from self-assembled aggregates of the probes formed by coordination association with multiple Cu 2+ ions. Coordination association of the probes with Cu 2+ is weakened with an increase in the chain length of the probes due to longer distance between the amide oxygen and the diacetic acid binding sites. In contrast, the green fluorescence intensity is not related to the coordination association strength; some probes show high fluorescence intensity. This is probably because alkyl chains sterically affect the alignment of the probes during aggregation interaction and, hence, produces aggregates with different fluorescence property.

Photocatalytic activity of TiO 2 particles embedded in mesoporous silica (TiO 2 @MPS), prepared by surfactant-templating method with a TiO 2 colloidal suspension, has been studied in water with molecular oxygen. Photocatalytic reactions of several kinds of aromatic molecules with TiO 2 @MPS reveal that less polar substrates show high reactivity, while polar substrates show much lower reactivity. Electron spin resonance analysis with spin-trapping reagents reveals that less polar substrates diffuse easily into the pore of the catalysts and react efficiently with short-lived hydroxyl ( OH) radicals formed at the surface of inner TiO 2 particles, resulting in a high reactivity. In contrast, polar substrates cannot diffuse into the pores and hence, shows a low reactivity. The photocatalytic activity of TiO 2 @MPS driven by the substrate polarity is applicable to selective transformation of a less polar reactant to a polar product, such as hydroxylation of benzene to phenol with high selectivity (>69%).

Effects of poly- N -isopropylacrylamide (polyNIPAM) on the fluorescence properties of core/shell type CdS/Cd(OH) 2 nanoparticles (NPs) have been studied in water. The NPs show strong fluorescence at low temperature, but the intensity decreases at >32 °C, allowing an on–off fluorescence switching by temperature. The heat-induced fluorescence quenching is due to the phase transition of polyNIPAM from coil to globule state. The NPs in solution associate with polyNIPAM via a hydrogen bonding interaction. Upon heating the solution, the NPs are confined within the polymer matrices during polymer aggregation. The aggregated polymer suppresses the incident absorption of inner NPs, resulting in fluorescence quenching. A notable feature obtained by the polyNIPAM addition is the enhanced thermal stability of NPs. The NPs confined within the polymer matrices are separated from each other. This therefore suppresses the coalescence of NPs, resulting in high stability even at high temperature.

A simple copolymer, poly(NIPAM- co -RD), consisting of N -isopropylacrylamide (NIPAM) and rhodamine (RD) units, behaves as a fluorescent temperature sensor exhibiting selective fluorescence enhancement at a specific temperature range (25–40 °C) in water. This is driven by a heat-induced phase transition of the polymer from coil to globule . At low temperature, the polymer exists as a polar coil state and shows very weak fluorescence. At >25 °C, the polymer weakly aggregates and forms a less polar domain within the polymer, leading to fluorescence enhancement. However, at >33 °C, strong polymer aggregation leads to a formation of huge polymer particles, which suppresses the incident light absorption by the RD units and shows very weak fluorescence. In the present work, effects of polymer concentration and type of acrylamide unit in the polymer have been investigated. The increase in the polymer concentration in water leads to a formation of less polar domain even at low temperature and, hence, widens the detectable temperature range to lower temperature. Addition of N - n -propylacrylamide (NNPAM) or N -isopropylmethacrylamide (NIPMAM) component to the polymer, which has lower or higher phase transition temperature than that of NIPAM, enables the aggregation temperature of the polymer to shift. This then shifts the detectable temperature region to lower or higher temperature.

This article reviews recent advances in selective organic transformations, both in gas and liquid media, using titanium oxide-based photocatalysts. Several photocatalytic reactions, such as oxidation, reduction, and coupling reactions, proceed highly efficiently and selectively without requiring harmful and dangerous chemical reagents and without harmful byproducts. In addition, multistep processes usually required for conventional synthesis of various kinds of valuable compounds can be simplified to a one-pot reaction when in photocatalytic systems. Photocatalytic transformations will therefore play a very important role for organic synthesis in an economically and environmentally friendly way. This review article demonstrates that titanium oxide-based photocatalysts have a great potential as a versatile tool in “green” organic synthesis.

A rhodamine–azacrown ether conjugate ( 1 ) demonstrates Fe(III)-selective green fluorescence, while showing Hg(II)-selective orange fluorescence. This is the first example of rhodamine-based fluorescent probe that shows dual channel fluorescence for two different metal cations.

An anthracene (AN) derivative bearing azacrown ether (1-aza-18-crown-6) and cyclen (1,4,7,10-tetraazacyclododecane) receptors ( L1 ) has been synthesized. Effects of proton (H + ) and metal cations (K + and Zn 2+ ) on the fluorescence properties of L1 have been studied in water and methanol. In water, H + addition to L1 leads to a fluorescence intensity ( I F ) increase. Potentiometrical pH titration reveals that strong I F enhancement of L1 requires monoprotonation of both azacrown and cyclen moieties. Addition of Zn 2+ and/or K + is ineffective for I F enhancement because these cations do not coordinate with the azacrown moiety, leading to an electron transfer (ET) from the azacrown nitrogen to the photoexcited AN moiety. In methanol, the azacrown and cyclen moieties of L1 coordinate with K + and Zn 2+ , respectively. Zn 2+ or K + addition to L1 shows very small or moderate I F enhancement because of ET from the uncoordinated azacrown or cyclen nitrogen to the excited AN. Addition of both K + and Zn 2+ , however, still shows moderate I F enhancement, although both macrocycles coordinate with the respective metal cations. Ab initio calculation reveals that the azacrown–K + coordination is weakened by an electrostatic repulsion between K + and Zn 2+ within the complex. This allows ET from the azacrown nitrogen to the excited AN, resulting in an insufficient I F enhancement.

A wide-band-gap semiconductor diamond has recently emerged as an important and promising material for a wide field of optoelectronic and electronic applications. In traditional chemical vapor deposition (CVD) diamond synthesis on a substrate, such as silicon single crystal, hydrogen radicals were thought to be inevitable. In this work, we synthesized diamond particles of wide-band-gap semiconductor on a substrate without flammable hydrogen gas. With our work, safer and easier diamond synthesis was realized. In our present technique, we call it “hydrogen-free diamond synthesis”. The graphite rods were used as heaters and, at the same time, carbon sources. In argon (99.99%; 4N), high-purity argon (6N), helium (4N5) or nitrogen (4N) atmosphere, without hydrogen gas, diamond particles were synthesized with the graphite rod heating method for the first time in the world. One-micrometer-diameter particles in argon gas, 0.8 μm particles in high-purity argon, 0.6 μm particles in helium, and 0.4 μm particles in nitrogen, were all confirmed as diamond with the SEM photographs and Raman spectroscopy; results will be reported in this paper.

Photocatalytic oxidation of neat cyclohexane (CHA) with molecular oxygen was carried out using hydrophobically modified Cr-containing mesoporous silica under visible light. Two catalysts (Cr/MOS and Cr/MOS-cal) containing highly dispersed chromate species were synthesized by Cr impregnation onto mesoporous organosilica (MOS) prepared with tetraethyl orthosilicate (TEOS) and 1,2-bis(triethoxysilyl)ethane (BTESE). Cr/MOS was synthesized by Cr impregnation onto MOS followed by calcination, and Cr/MOS-cal was synthesized by calcination of MOS, Cr impregnation, and calcination. Both catalysts promoted partial CHA oxidation with high selectivity (>86%). Cr/MOS-cal synthesized with 10% BTESE showed the highest catalytic activity, due mainly to the higher surface hydrophobicity, which accelerated access of CHA to the chromate species. ESR analysis revealed that the tetrahedrally coordinated chromate species ( T d 6 + ) on Cr/MOS-cal were photoexcited and formed highly reduced T d 4 + ∗ species with high catalytic activity. This also contributed to the high catalytic activity of Cr/MOS-cal.

Dinuclear lanthanide (Ln=Tb 3+ or Eu 3+ ) complexes (Ln 2 L2 ) of two octadentate macrocyclic polyaminopolycarboxylic ligands connected through a benzophenone (BP) moiety ( L2 ) have been synthesized. Sensitized luminescence properties of Ln 2 L2 in water have been studied in comparison to those of BP-conjugated mononuclear Ln complexes (Ln L1 ). The luminescence intensity of Tb 2 L2 is lower than that of Tb L1 because of lower triplet quantum yield of the BP moiety. In contrast, Eu 2 L2 shows higher intensity than Eu L1 . For both Eu complexes, energy level of triplet excited-state BP ( 3 BP*) is only 3 kJ mol −1 higher than that of 5 D 2 excited-state of Eu 3+ . The 5 D 2 state formed by a triplet-energy transfer (TET) from 3 BP* is therefore deactivated by a back energy transfer (BET) to the ground-state BP, resulting in low luminescence intensity of Eu L1 . In contrast, within Eu 2 L2 , TET from 3 BP* to 5 D 0 state of two Eu 3+ ions is accelerated, thus leading to higher luminescence intensity. Another notable feature of Eu 2 L2 is the luminescence quantum yield independent of its concentration. In contrast, for Eu L1 system, an intermolecular BET occurs from 5 D 2 state of Eu 3+ to the ground-state BP conjugated to another Eu L1 complex, resulting in a yield decrease with the concentration increase.

Unmodified fluorescein (1) behaves as a fluorescent chemosensor for F− detection, where the F−-induced fluorescence enhancement is driven by a transfer of the phenolic OH protons to F−.

A simple ligand (L1), a diethylenetriamine bearing two end quinoline fragments, was synthesized. Without metal cations, L1 shows no fluorescence at pH 2–13; however, Zn2+ addition creates strong fluorescence at pH 5–12. The emission intensity exhibits linear and stoichiometrical response to the Zn2+ amount. No remarkable emission enhancement was, however, observed for other cations.

A simple copolymer, poly(NIPAM-co-N_AN), consisting of N-isopropylacrylamide (NIPAM) and 9-aminomethylanthracene (N_AN) units behaves as a temperature-driven on/off fluorescence indicator of pH window (2–12): showing an ‘on–off’ fluorescence intensity profile against the pH window at 15 °C, while showing an ‘off–on–off’ profile at 34 °C.

Sensitized luminescence behavior of lanthanide (Ln=Eu 3+ , Tb 3+ ) macrocyclic cyclen (1,4,7,10-tetraazacyclododecane) complexes bearing one or four benzophenone (BP) moieties as antenna (Ln L1 and Ln L4 ) has been studied in water. Despite higher molar extinction coefficient of Eu L4 owing to four antennae, it shows only one-thirtieth the luminescence intensity of Eu L1 . Energy level of triplet excited–state of BP antenna ( E T ) is only a few kJ mol −1 higher than that of 5 D 2 excited–state of Eu 3+ , thus promoting a back energy transfer (BET) from 5 D 2 of Eu 3+ to ground-state BP antennae. On Eu L4 bearing four antennae, BET occurs more rapidly than that on Eu L1 , thus exhibiting much weaker luminescence. For Tb complexes, the energy gap between E T of BP antenna and 5 D 4 excited state of Tb 3+ is large enough (>13 kJ mol −1 ), such that practically no BET occurs. The luminescence intensity of Tb L4 is, however, lower (two-third) than that of Tb L1 . Time-resolved luminescence measurement reveals that hydration number of Tb 3+ within Tb L4 is twice that within Tb L1 . This is because the structural distortion of ligands on Tb L4 , caused by an intramolecular dipole–dipole interaction among the BP antennae, allows coordination of higher number of H 2 O molecules to Tb 3+ , thus leading to a strong Tb luminescence quenching via O–H oscillators.

A new rhodamine-based fluorescent chemosensor ( 1 ) for transition metal cations was synthesized by one-step facile condensation of rhodamine B and 2-aminopyridine. Without metal cations, 1 is colorless and nonfluorescent, whereas addition of metal cations (Fe 3+ , Hg 2+ , Pb 2+ , and Fe 2+ ) leads to an obvious color change to pink and an appearance of orange fluorescence.

A wide bandgap semiconductor, diamond, has recently emerged as important and promising materials for a wide field of optoelectronic and electronic applications. With graphite spark method in hydrogenic atmosphere, we successfully synthesized diamond particles in 3–5 μm diameter in only ten seconds and in 1–2 μm diameter in two seconds. The resultant particles were observed with SEM (Scanning Electron Microscope) images, and confirmed as diamond by sharp peak on 1331 cm −1 with Raman spectrometer. With this study, we searched for precursors with various experimental conditions, such as hydrogen pressures and/or graphite temperatures. For gaseous species identification, OES (Optical Emission Spectroscopy) results will be reported on this presentation, and the preliminary synthesis mechanism for ‘spark method’ will be presented.

CdS nanoparticles, prepared in reverse micellar systems, were immobilized onto two types of thiol-modified periodic mesoporous organosilicates (PMOS), t-PMOS(I) and t-PMOS(II) by a simple procedure via the addition of t-PMOS and mild stirring. A particle-sieving effect of the t-PMOS was observed, in that the immobilization of the CdS nanoparticles was decreased with increasing the nanoparticle size. The resulting CdS-PMOS(I) and CdS-PMOS(II) were then used as photocatalysts for the generation of H 2 from 2-propanol aqueous solution. CdS-PMOS(II), which was more stable against photoirradiation, showed higher photocatalytic activity, compared to CdS-PMOS(I). The quantity of H 2 generated on the PMOS-immobilized CdS nanoparticles was greater than that obtained from mesoporous silica (MCM-41)-immobilized CdS nanoparticles (CdS-L-FM41).

Yttrium oxysulfide upconverting phosphor nanoparticles, doped with Yb as a sensitizer and Er (or Ho, Tm) as an activator, have been prepared via a solid-gas reaction using precursor oxalate particles obtained in an emulsion liquid membrane (ELM, water-in-oil-in-water (W/O/W) emulsion) system. The resulting Y(2)O(2)S:Yb,Er particles, mainly smaller than 50 nm in diameter, demonstrated green upconversion emission under infrared excitation (lambdaex = 980 nm) via a two-photon process. Distinct green and blue upconversion emission were also demonstrated under the same infrared excitation from Y(2)O(2)S:Yb,Ho and Y(2)O(2)S:Yb,Tm nanoparticles, respectively. These upconverting phosphor nanoparticles, together with Y(2)O(3):Yb,Er infrared-to-red upconverting phosphor particles, with different emission under the same infrared excitation may be applied to the luminescent reporter materials for the detection of the targeted analyte in multiplexed assays.

S -Methylsulfonium salts, obtained by a new desulfurization process for light oil based on methylation of sulfur-containing compounds using CH 3 I and AgBF 4 , were used as a methyl-transfer agent for transmethylation of 2-methyl-2-octene. The sulfonium salts obtained from light oil showed higher transmethylation activity than the salts of dibenzothiophene (DBT) and benzothiophene (BT), used as model sulfonium salt. The salts obtained from light oil are derived from highly alkyl-substituted DBTs and BTs, of low nucleophilicity (low electron density on the sulfur atom), and release the methyl group easily, thus giving the higher transmethylation activity. The product distribution was almost the same as that obtained by the model sulfonium salts, suggesting that the salts obtained from light oil are a potential effective methyl-transfer agent.

TiP 2 O 7 carbon composite photocatalyst was successfully prepared by using ion-exchanged resin (C467) containing amino phosphate by metal ion-exchanged carbothermal reduction (MIER-CTR) method using TiCl 3 and TiCl 4 . During the carbonization process in nitrogen, the pre-oxidation (300–350 °C) in air is essential for producing homogeneously dispersed TiP 2 O 7 on the carbon matrix. In the absence of pre-oxidation, the resin was melted. The carbonization temperature 500 °C was found to be suitable for producing single phase TiP 2 O 7 with higher yields. Powder X-ray diffraction (XRD) and Raman spectroscopic results suggest the formation of TiP 2 O 7 , while X-ray diffraction results reveal that the crystallite size was less than 35 nm. UV-Vis studies show that the band gap of TiP 2 O 7 was 3.32 eV. The TiP 2 O 7 carbon composite catalyst was applied for the photocatalytic decomposition of 2-propanol at 30 °C using a mercury lamp (365 nm).

CdS nanoparticles, as prepared in reverse micellar systems, were incorporated into alkanedithiol-modified Zn-doped SBA-15 mesoporous silica (dtz.sbnd;ZnSBA-15; pore diameter, ca. 4 nm), which were themselves prepared via hydrolysis of tetraethylorthosilicate (TEOS) in the presence of Zn(NO(3))(2) and triblock copolymer, as a nonsurfactant template and pore-forming agent, followed by contact with dithiol molecules. A particle-sieving effect for the dtz.sbnd;ZnSBA-15 was observed, in that the incorporation of the nanoparticles was remarkably decreased with increasing the nanoparticle size. The resulting CdSz.sbnd;ZnSBA-15 composite was then used as photocatalysts for the generation of H(2) from 2-propanol aqueous solution. Under UV irradiation (lambda300 nm), a high photocatalytic activity was observed for this composite material. This is effected by electron transfer from the photoexcited ZnS (dithiol-bonded Zn on SBA-15) to CdS nanoparticles. The photocatalytic activity is increased with a decrease in the number of methylene groups in the dithiol molecules, according to the rank order 1,10-decanedithiol1,6-hexanedithiol1,2-ethanedithiol.

Advanced liquid–liquid extraction combined with the conversion of the metal species with chemical reactions has been investigated. The complex formation reaction with water-soluble complexing reagent and the photochemical redox reaction for metal ions are focused. In the case of complex formation reaction, ethylenediaminetetraacetic acid (EDTA) was added to the aqueous phase of the extraction system. The separation of adjacent rare earth metals improves, due to the difference of the complex formation ability between metals and EDTA. The design of separation process of the metals with countercurrent mixer-settler cascade was also investigated with simulation based on the extraction equilibrium, determined up to high loadings of the extractant, and the material balance equations. In the case of photochemical redox reaction, the photoreductive stripping of Eu from Sm/Eu/Gd mixture and the photooxidative extraction of Ce from La/Ce/Pr mixture were carried out. The extractability of the target metals changes dramatically when their valences are changed, and then the effective separation can be achieved.

Size- (submicrometer-sized) and morphology- (spherical) controlled composite Gd-Eu oxalate particles were prepared in an emulsion liquid membrane (water-in-oil-in-water emulsion) system. The oxalate particles thus prepared were calcined in air to obtain Gd(2)O(3) : Eu(3+) phosphor particles and in sulfur atmosphere to obtain Gd(2)O(2)S : Eu(3+) phosphor particles. These submicrometer-sized spherical phosphor particles showed photoluminescence properties with emission peak at 614 nm for Gd(2)O(3) : Eu(3+) and 628 nm for Gd(2)O(2)S : Eu(3+).

The separation of rare earth metals using microcapsules (MC) consisting styrene (St)–divinylbenzene (DVB) copolymer and containing bis(2-ethylhexyl)phosphinic acid (PIA-226) has been investigated. Microcapsules containing PIA-226 can be prepared by adding PIA-226 to the dispersed phase during the preparation process. The extraction of rare earth metals with the microcapsules progresses via the same scheme, as proposed in the conventional liquid–liquid extraction system up to a loading ratio of 0.4 and the extraction behavior can be expressed using the same equilibrium formulations, as determined in the liquid–liquid extraction system. A high loading of rare earth metals up to a loading ratio of about 0.8 is achieved in the microcapsule system, while that in the liquid–liquid extraction system is limited to about 0.4 due to emulsion difficulties. Separation studies for Pr/Sm using a column packed with microcapsules show that Pr with high purity is obtained initially from the aqueous effluent solution, and that Sm with high purity is finally obtained in the microcapsules.

We report the dielectric relaxation in a ternary system in which a trace amount of poly(n-hexyl isocyanate) (PHIC) is dissolved in concentrated toluene solutions of polybutadiene (PB). The dielectric response is due to the rod-like PHIC molecules having high dipole moment along its chain contour. Solutions of PB form entanglement networks which retard the reorientation of the PHIC molecules. With increasing concentration (CPB) of PB from 0 to 40 wt% the relaxation behaviour changed at a crossover concentration CPB+. In the range below CPB+, the relaxation time τ for reorientation of the PHIC molecules increased on account of the effect of entanglement. However above CPB+, τ decreased and at the same time the relaxation strength decreased with increasing CPB. The crossover concentration CPB+ depended on the molecular weight M of the PHIC, i.e. C+PB=0.13 at M=29,000, and CPB+=0.25 at M=20,000. The decrease of the relaxation strength can be attributed to the reduction of the effective dipole moment due to the restriction of motions of the PHIC chains in entanglement networks of PB chains.