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1.
Hosono E Fujihara S Honma I Zhou H 《Journal of the American Chemical Society》2005,127(39):13458-13459
We first fabricated the superhydrophobic film with a water contact angle of 178 degrees based on a perpendicular nanopin fractal structure by a bottom-up process. Until now, only materials with an original water contact angle larger than 90 degrees , which is classified as hydrophobicity, could be used to fabricate the superhydrophobic film (>170 degrees ) according to the possible fractal structure by a top-down process. Now, in this work, a water contact angle of about 178 degrees can be achieved using a lauric acid-coated film with an original contact angle of 75 degrees , which is classified as hydrophilicity, based on an ideal fractal structure for the superhydrophobic surface which is fabricated by the nanosize pin with 6.5 nm diameter. 相似文献
2.
A new type of gold nanoparticle with a zwitterionic liquid function (zwitter-Au) has been prepared using an imidazolium sulfonate-terminated thiol as a capping agent. Zwitter-Au was found to be remarkably stable in high concentrations of aqueous electrolytes, ionic liquids, and protein. 相似文献
3.
The synthesis and properties of novel anthracene-bridged porphyrin dimers having an oxomolybdenum(V) porphyrin unit, H(2)(DPA)[Mo(V)O(OMe)] (1) and (DPA)[Mo(V)O(OMe)][Zn(II)(MeOH)] (2), and the relevant monomer porphyrin complexes Mo(V)O(MPP)OMe (3) and Zn(II)(MPP) (4) are presented. An oxomolybdenum(V) unit was introduced into one of the two porphyrins in DPA to give 1, which has a free-base porphyrin unit. By introducing a zinc(II) ion to the free-base part, a mixed-metal complex of 2 was prepared and isolated. The structure of 2 was analyzed by X-ray crystallography (2.(7)/(6)CH(2)Cl(2), triclinic, P(-)1 (no. 2), a = 15.2854(12) A, b = 19.9640(15) A, c = 13.6915(12) A, alpha = 90.968(3), beta = 113.108(4), gamma = 96.501(4), Z = 2, R1 = 9.9, wR2 = 19.2). The structure of 2 demonstrated that a methanol is stably coordinated to the Zn(II) ion with the aid of a hydrogen bond to the methoxo ligand on the Mo(V) ion in the binding pocket of DPA. The electrochemical measurements of 2 suggested that the methanol was kept in the pocket of DPA in solution even at the reduced state of the molybdenum ion. 相似文献
4.
M. Kito S. Kimura N. Otsuka K. Fujihara M. Ishino Y. Matsui 《Optical and Quantum Electronics》1996,28(5):503-511
We have investigated the temperature dependencies of the slope efficiency and the threshold current for strained multiquantum well (MQW) lasers as a parameter of the well number. Smaller well numbers mean larger temperature dependencies of the slope efficiency and the threshold current, while larger well numbers mean larger internal loss and broadening of the photoluminescence linewidth of the MQW structure. Furthermore, the change in the slope efficiency with temperature change is related to the change in internal loss. In this work, the 1.3-m strained MQW laser with a compressive strain of 1.0% and 7 wells shows the highest output power of 6.8 mW for an injection current of 50 mA and the lowest threshold current of 5.5 mA at 85°C, and the lowest variation in output power of 2.0 dB from 25–85°C at injection current of 50 mA. 相似文献
5.
New pyrrolylalkanethiolate-stabilized gold and palladium nanoparticles have been prepared: electrochemical polymerization of their metal nanoparticles and their TEMPO-derivatized metal nanoparticles gave the remarkably stable poly(pyrrole metal nanoparticle) films on metal electrodes. 相似文献
6.
Fabrication of mesoporous ZnO nanosheets from precursor templates grown in aqueous solutions 总被引:1,自引:0,他引:1
Keita Kakiuchi Eiji Hosono Toshio Kimura Hiroaki Imai Shinobu Fujihara 《Journal of Sol-Gel Science and Technology》2006,39(1):63-72
Mesoporous ZnO nanosheets were successfully prepared by pyrolytic transformation of zinc carbonate hydroxide hydrate, Zn4CO3(OH)6·H2O. The nanosheets were initially formed as assemblies on glass substrates during chemical bath deposition (CBD) in aqueous
solutions of urea and zinc acetate dihydrate, zinc chloride, zinc nitrate hexahydrate, or zinc sulfate heptahydrate at 80°C.
It was key to induce heterogeneous nucleation of Zn4CO3(OH)6·H2O by promoting a gradual hydrolysis reaction of urea and controlling the degree of supersaturation of zinc hydroxide species.
Morphology of Zn4CO3(OH)6·H2O was largely influenced by the anions present in the CBD solutions. The Zn4CO3(OH)6·H2O nanosheets were transformed into wurtzite ZnO by heating at 300°C in air without losing the microstructural feature. 相似文献
7.
High concentrations of arsenic were observed in the blubber of ringed seals (Pusa hispida) in our previous study. To better understand the arsenic accumulation in blubber of marine mammals, arsenicals in the blubber of ringed seal were characterized using high performance liquid chromatography–inductively coupled plasma mass spectrometry (HPLC–ICPMS). The most predominant water-soluble arsenical in the blubber was dimethylarsinic acid (DMA), in spite of the predominance of arsenobetaine in other tissues. Lipid-soluble fraction was hydrolyzed under mild (tetraethylammonium hydroxide (TEAH) hydrolysis) and strong (NaOH hydrolysis) conditions, and then an aliquot of hydrolysate was injected onto HPLC–ICPMS. Both TEAH-labile and TEAH-stable/NaOH-labile lipid-soluble fractions contained precursors of DMA. These results suggest that the blubber might be the pool of DMA and DMA-containing precursors in ringed seals. 相似文献
8.
9.
Rational Design for Rotaxane Synthesis through Intramolecular Slippage: Control of Activation Energy by Rigid Axle Length 下载免费PDF全文
Hiroshi Masai Dr. Jun Terao Dr. Tetsuaki Fujihara Dr. Yasushi Tsuji 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(19):6624-6630
We describe a new concept for rotaxane synthesis through intramolecular slippage using π‐conjugated molecules as rigid axles linked with organic soluble and flexible permethylated α‐cyclodextrins (PM α‐CDs) as macrocycles. Through hydrophilic–hydrophobic interactions and flipping of PM α‐CDs, successful quantitative conversion into rotaxanes was achieved without covalent bond formation. The rotaxanes had high activation barrier for their de‐threading, so that they were kinetically isolated and derivatized even under conditions unfavorable for maintaining the rotaxane structures. 1H NMR spectroscopy experiments clearly revealed that the restricted motion of the linked macrocycle with the rigid axle made it possible to control the kinetic stability by adjusting the length of the rigid axle in the precursor structure rather than the steric bulkiness of the stopper unit. 相似文献
10.
Kazuhiko Semba Masataka Shinomiya Prof. Dr. Tetsuaki Fujihara Prof. Dr. Jun Terao Prof. Dr. Yasushi Tsuji 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(22):7125-7132
The highly selective copper‐catalyzed hydroboration of allenes has been developed. Allylboranes and alkenylboranes were selectively prepared by the judicious choice of catalytic species (copper hydride and boryl copper). Furthermore, two types of alkenylboranes could be selectively synthesized by the choice of an appropriate ligand. Mechanistic studies confirmed that the protonation of a (Z)‐σ‐allyl copper species, which was isolated and structurally characterized by single‐crystal X‐ray diffraction, was a key step in these reactions. Besides allenes, this method is also applicable to the selective hydroboration of 1,3‐diene derivatives to afford allylboranes and homoallylboranes. 相似文献