Barrier effect of dendrons on TiO2 particles in dye sensitized solar cells

The short circuit current of dye sensitised solar cells increased significantly by the simple addition of polyester hydroxyl acetylene bis(hydroxymethyl)propanoic acid dendrons on TiO(2) nanoparticles, resulting in a very high overall energy conversion efficiency.     

Selective CO2 adsorption in a flexible non-interpenetrated metal-organic framework

We have prepared a flexible metal-organic framework and demonstrated that when activated by supercritical CO(2) it has greater gas sorption capacities than that activated by the heat-evacuation method, and it selectively adsorbs CO(2) over N(2) at room temperature.     

Isoconiferoside, a new phenolic glucoside from seeds of Panax ginseng

A new phenolic glucoside, isoconiferoside (1), was isolated from the seeds of Panax ginseng (Araliaceae). The structure was determined to be 9-O-[β-D-glucopyranosyl-(1 --> 6)-β-D-glucopyranosyl]-trans-coniferyl alcohol based on spectroscopic analyses (1H- and 13C-NMR, DEPT, COSY, HMQC, and HMBC) and acid hydrolysis.     

Graphene-based multifunctional iron oxide nanosheets with tunable properties

We report the synthesis of graphenes with tunable properties due to the growth of needlelike iron oxide (IO) nanoparticles on their surfaces. The electrical conductivity, flexibility, and magnetic properties of graphene nanosheets (GNSs) could be tuned on demand by fine controlling both the surface coverage and the length of the IO nanoneedles. The degree of coverage of the IO nanoparticles on the surface of the GNSs made it possible to control the resulting properties of the IO/GNSs on demand. As examples of their utility, paperlike materials were generated by simple filtration, and the resulting IO/GNS nanocomposites showed extraordinary removal capacity and fast adsorption rates for As(V) and Cr(VI) ions in water. Another possible application is the preparation of multifunctional films equipped with conductivity, flexibility, and magnetic properties. The fabrication process is easy to scale up at a low cost. In addition, both the colloidal solution and film forms of the resulting IO/GNSs were effective for removal of heavy metal ions, meaning this material could be utilized for actual industrial applications.     

A New Efficient Synthetic Method for 3‐Iodothyronamine and Its Potent Hypothermic Efficacy

We developed a new efficient synthetic method for a 3‐iodothyronamine (T₁AM) that has advantages of less synthetic steps and much higher overall yield compared to those in the conventional method. Our animal study showed that T₁AM synthesized by the method exerted a potent hypothermic effect in non‐hibernator mice.     

Identification of tissue-specific targeting peptide

Using phage display technique, we identified tissue-targeting peptide sets that recognize specific tissues (bone-marrow dendritic cell, kidney, liver, lung, spleen and visceral adipose tissue). In order to rapidly evaluate tissue-specific targeting peptides, we performed machine learning studies for predicting the tissue-specific targeting activity of peptides on the basis of peptide sequence information using four machine learning models and isolated the groups of peptides capable of mediating selective targeting to specific tissues. As a representative liver-specific targeting sequence, the peptide ??DKNLQLH?? was selected by the sequence similarity analysis. This peptide has a high degree of homology with protein ligands which can interact with corresponding membrane counterparts. We anticipate that our models will be applicable to the prediction of tissue-specific targeting peptides which can recognize the endothelial markers of target tissues.     

Stamping transfer of a quantum dot interlayer for organic photovoltaic cells

An organophilic cadmium selenide (CdSe) quantum dot (QD) interlayer was prepared on the active layer in organic solar cells by a stamping transfer method. The mother substrate composed of a UV-cured film on a polycarbonate film with strong solvent resistance makes it possible to spin-coat QDs on it and dry transfer onto an active layer without damaging the active layer. The QD interlayers have been optimized by controlling the concentration of the QD solution. The coverage of QD particles on the active layer was verified by TEM analysis and fluorescence images. After insertion of the QD interlayer between the active layer and metal cathode, the photovoltaic performances of the organic solar cell were clearly enhanced. By ultraviolet photoelectron spectroscopy of CdSe QDs, it can be anticipated that the CdSe QD interlayer reduces charge recombination by blocking the holes moving to the cathode from the active layer and facilitating efficient collection of the electrons from the active layer to the cathode.     

Hydrophilicity Control of Visible‐Light Hydrogen Evolution and Dynamics of the Charge‐Separated State in Dye/TiO2/Pt Hybrid Systems

Visible‐light‐driven H₂ evolution based on Dye/TiO₂/Pt hybrid photocatalysts was investigated for a series of (E)‐3‐(5′‐{4‐[bis(4‐R¹‐phenyl)amino]phenyl}‐4,4′‐(R²)₂‐2,2′‐bithiophen‐5‐yl)‐2‐cyanoacrylic acid dyes. Efficiencies of hydrogen evolution from aqueous suspensions in the presence of ethylenediaminetetraacetic acid as electron donor under illumination at λ>420 nm were found to considerably depend on the hydrophilic character of R¹, varying in the order MOD (R¹=CH₃OCH₂, R²=H)≈ MO4D (R¹=R²=CH₃OCH₂)> HD (R¹=R²=H)> PD (R¹=C₃H₇, R²=H). In the case of MOD /TiO₂/Pt, the apparent quantum yield for photocatalyzed H₂ generation at 436 nm was 0.27±0.03. Transient absorption measurements for MOD ‐ or PD ‐grafted transparent films of TiO₂ nanoparticles dipped into water at pH 3 commonly revealed ultrafast formation (<100 fs) of the dye radical cation (Dye^.+) followed by multicomponent decays, which involve minor fast decays (<5 ps) almost independent of R¹ and major slower decays with significant differences between the two samples: 1) the early decay of the major components for MOD is about 2.5 times slower than that for PD and 2) a redshift of the spectrum occurred for MOD with a time constant of 17 ps, but not for PD . The substituent effects on H₂ generation as well as on transient behavior have been discussed in terms substituent‐dependent charge recombination (CR) of Dye^.+ with electrons in bulk, inner‐trap, and/or interstitial‐trap states, arising from different solvent reorganization.     

Polydiacetylene‐Based Electrospun Fibers for Detection of HCl Gas

Polydiacetylenes (PDAs), a family of conjugated polymers, are very intriguing materials in several aspects. Especially, the stimulus‐induced apparent blue‐to‐red transition of the PDAs has led to the development of a variety of PDA‐based chemosensors. In the current work, we synthesized PDA monomers bearing trimethyl amine (PCDA‐DMEDA) and incorporated them with Poly(ethylene oxide) (PEO) into electrospun fibers. For the first time, we successfully demonstrated that PDA‐based electrospun fibers can be used for the naked‐eye detection of HCl gas by simple color change (blue to red).     

Effect of chlorinating reagents on Zr recovery from Zircaloy-4 hull wastes: reaction behavior simulation by using the HSC code

Chlorination reaction behavior of Zircaloy-4 (Zry-4) was simulated by using the HSC code for three different chlorinating reagents of Cl₂, HCl, and CCl₄. Four major components (Zr, Sn, Fe, and Cr) of Zry-4 and their oxides which were produced during an oxidative decladding process were considered for the theoretical calculation. The simulation results revealed that Cl₂ might convert metallic Zr, Sn, Fe, and Cr into their chloride forms, while oxides might not react with Cl₂ at 380 °C. When HCl was employed as the chlorinating reagent, it was suggested that metallic Zr, Sn, and Cr might react with HCl while Fe and oxides might not. In the case of CCl₄, it was shown that CCl₄ could react with all of the metallic and oxide components to produce most amount of ZrCl₄ when compared with Cl₂ and HCl cases. Reaction behavior of the chlorinating reagents with residual spent nuclear fuel constituents (U₃O₈, MoO₃, Pd, BaO, Y₂O₃, SrO, Rh₂O₃, RhO₂, La₂O₃, CeO₂, and Nd₂O₃) was also performed, and it was revealed that Cl₂ and HCl might produce (PdCl₂, BaCl₂, SrCl₂, RhCl₃, LaCl₃, and NdCl₃) and (BaCl₂, YCl₃, SrCl₂, RhCl₃, LaCl₃, and NdCl₃), respectively. Although these by-products are produced, it was suggested that highly pure ZrCl₄(g) which contains FeCl₃(g) and SnCl₄(g) as impurities might be recovered when Cl₂ or HCl is employed as a chlorinating reagent because other by-products have higher boiling point than the reaction temperature of this study (380 °C). On the other hand, the theoretical calculation results showed that CCl₄ might react with all the residual spent fuel constituents to produce additional gaseous impurities of UCl₆ and MoCl₅ to reduce the purity of ZrCl₄ product.