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Senes A, Meskers SCJ, Greiner H, Suzuki K, Kaji H, Adachi C, Wilson JS, Janssen RAJ. Increasing the horizontal orientation of transition dipole moments in solution processed small molecular emitters. JOURNAL OF MATERIALS CHEMISTRY. C 2017; 5:6555-6562. [PMID: 29308204 PMCID: PMC5735365 DOI: 10.1039/c7tc01568b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 06/12/2017] [Indexed: 05/13/2023]
Abstract
The efficiency of organic light emitting diodes (OLEDs) can be improved by controlling the orientation of the transition dipole moment of the emitters. Currently, no effective methods exist for orienting the transition dipole moments in solution processed active layers for OLEDs. We investigate the orientation of the transition dipole moment of small molecular emitters in a host matrix of poly(9,9-dioctylfluorene) (PFO) by means of angle dependent luminescence intensity measurements. The polymer chains of the host orient predominantly in the plane of the film. Fluorescent p-phenylenevinylene oligomers with 6 and 7 repeat units (OPV6, OPV7) are found to also orient preferentially horizontally. The orientation of the emitters can be improved by thermal annealing with up to 90% of transition dipole moments oriented in the plane of the film. The phosphorescent emitter Ir(MDQ)2(acac) shows a degree of horizontal orientation in the polymeric host matrix lower than that which is observed for oligomers, but as high as is observed for the same emitter in evaporated layers. A carbazole derivative capable of thermally activated delayed fluorescence shows a small preference for vertical orientation within the polymer host. The strong orientation of OPV6 and OPV7 in the oriented polymer host is rationalized in terms of their high aspect ratios. The use of PFO as host material in host/guest systems allows achieving horizontal orientation of transition dipole moments in solution processed oligomers and small molecular emitters.
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Gu Y, Inoue K, Shinohara S, Doi R, Kaji H, Hayashi H, Aung T, Tun T, Echigo Y, Wada M, Imamura M, Iwata H. Comparison of Different Collagenases in Isolation of Adult Pig Islets. Cell Transplant 2017. [DOI: 10.1177/096368979500401s14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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53
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Asakura T, Nishimura A, Kametani S, Kawanishi S, Aoki A, Suzuki F, Kaji H, Naito A. Refined Crystal Structure of Samia cynthia ricini Silk Fibroin Revealed by Solid-State NMR Investigations. Biomacromolecules 2017; 18:1965-1974. [DOI: 10.1021/acs.biomac.7b00441] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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54
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Shimizu T, Kanamori K, Maeno A, Kaji H, Doherty CM, Nakanishi K. Transparent Ethenylene-Bridged Polymethylsiloxane Aerogels: Mechanical Flexibility and Strength and Availability for Addition Reaction. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:4543-4550. [PMID: 28412818 DOI: 10.1021/acs.langmuir.7b00434] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Transparent, low-density ethenylene-bridged polymethylsiloxane [Ethe-BPMS, O2/2(CH3)Si-CH═CH-Si(CH3)O2/2] aerogels from 1,2-bis(methyldiethoxysilyl)ethene have successfully been synthesized via a sol-gel process. A two-step sol-gel process composed of hydrolysis under acidic conditions and polycondensation under basic conditions in a liquid surfactant produces a homogeneous pore structure based on cross-linked nanosized colloidal particles. Visible-light transmittance of the aerogels varies with the concentration of the base catalyst and reaches as high as 87% (at a wavelength of 550 nm for a 10 mm thick sample). Gelation and aging temperature strongly affect the deformation behavior of the resultant aerogels against uniaxial compression, and the obtained aerogels prepared at 80 °C show high elasticity after being unloaded. This highly resilient behavior is primarily derived from the rigidity of ethenylene groups, which is confirmed by a comparison with other aerogels with similar molecular structures, ethylene-bridged polymethylsiloxane and polymethylsilsesquioxane. Applicability of the addition reaction using a Diels-Alder reaction of benzocyclobutene has also been investigated, revealing that a successful addition takes place on the ethenylene linkings, which is verified using Raman and solid-state NMR spectroscopies. Insights into the effect of molecular structure on mechanical properties and the availability of surface functionalization provided in this study are important for realizing transparent aerogels with the desired functionality.
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Moon CK, Suzuki K, Shizu K, Adachi C, Kaji H, Kim JJ. Combined Inter- and Intramolecular Charge-Transfer Processes for Highly Efficient Fluorescent Organic Light-Emitting Diodes with Reduced Triplet Exciton Quenching. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1606448. [PMID: 28247545 DOI: 10.1002/adma.201606448] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Indexed: 06/06/2023]
Abstract
Inter- and intramolecular charge-transfer processes are combined using an exciplex-forming host and a thermally activated delayed fluorescent dopant, for fabricating efficient fluorescent organic light-emitting diodes along with the reduced efficiency roll-off at high current densities. Extra conversion on the host from triplet exciplexes to singlet exciplexes followed by energy transfer to the dopant reduces population of triplet excitons on dopant molecules, thereby reducing the triplet exciton annihilations at high current densities.
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Huang S, Huang Z, Cao P, Zujovic Z, Price JR, Avdeev M, Que M, Suzuki F, Kido T, Ouyang X, Kaji H, Fang M, Liu YG, Gao W, Söhnel T. "114"-Type Nitrides LnAl(Si 4-x Al x )N 7 O δ with Unusual [AlN 6 ] Octahedral Coordination. Angew Chem Int Ed Engl 2017; 56:3886-3891. [PMID: 28244628 DOI: 10.1002/anie.201612488] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Indexed: 11/10/2022]
Abstract
Aluminum-nitrogen six-fold octahedral coordination, [AlN6 ], is unusual and has only been seen in the high-pressure rocksalt-type aluminum nitride or some complex compounds. Herein we report novel nitrides LnAl(Si4-x Alx )N7 Oδ (Ln=La, Sm), the first inorganic compounds with [AlN6 ] coordination prepared via non-high-pressure synthesis. Structure refinements of neutron powder diffraction and single-crystal X-ray diffraction data show that these compounds crystallize in the hexagonal Swedenborgite structure type with P63 mc symmetry where Ln and Al atoms locate in anticuboctahedral and octahedral interstitials, respectively, between the triangular and Kagomé layers of [SiN4 ] tetrahedra. Solid-state NMR data of high-purity La-114 powders confirm the unusual [AlN6 ] coordination. These compounds are the first examples of the "33-114" sub-type in the "114" family. The additional site for over-stoichiometric oxygen in the structure of 114-type compounds was also identified.
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Huang S, Huang Z, Cao P, Zujovic Z, Price JR, Avdeev M, Que M, Suzuki F, Kido T, Ouyang X, Kaji H, Fang M, Liu YG, Gao W, Söhnel T. “114”-Type Nitrides LnAl(Si 4−x
Al
x
)N 7
O
δ
with Unusual [AlN 6
] Octahedral Coordination. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201612488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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58
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Huang S, Huang Z, Cao P, Zujovic Z, Price JR, Avdeev M, Que M, Suzuki F, Kido T, Ouyang X, Kaji H, Fang M, Liu YG, Gao W, Söhnel T. Innenrücktitelbild: “114”-Type Nitrides LnAl(Si 4−x
Al
x
)N 7
O
δ
with Unusual [AlN 6
] Octahedral Coordination (Angew. Chem. 14/2017). Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201702125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Huang S, Huang Z, Cao P, Zujovic Z, Price JR, Avdeev M, Que M, Suzuki F, Kido T, Ouyang X, Kaji H, Fang M, Liu YG, Gao W, Söhnel T. Inside Back Cover: “114”-Type Nitrides LnAl(Si 4−x
Al
x
)N 7
O
δ
with Unusual [AlN 6
] Octahedral Coordination (Angew. Chem. Int. Ed. 14/2017). Angew Chem Int Ed Engl 2017. [DOI: 10.1002/anie.201702125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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60
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Pélisson CH, Nakanishi T, Zhu Y, Morisato K, Kamei T, Maeno A, Kaji H, Muroyama S, Tafu M, Kanamori K, Shimada T, Nakanishi K. Grafted Polymethylhydrosiloxane on Hierarchically Porous Silica Monoliths: A New Path to Monolith-Supported Palladium Nanoparticles for Continuous Flow Catalysis Applications. ACS APPLIED MATERIALS & INTERFACES 2017; 9:406-412. [PMID: 27966866 DOI: 10.1021/acsami.6b12653] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Polymethylhydrosiloxane has been grafted on the surface of a hierarchically porous silica monolith using a facile catalytic reaction between Si-H and silanol to anchor the polymer. This easy methodology leads to the functionalization of the surface of a silica monolith, where a large amount of free Si-H bonds remain available for reducing metal ions in solution. Palladium nanoparticles of 15 nm have been synthesized homogeneously inside the mesopores of the monolith without any stabilizers, using a flow of a solution containing Pd2+. This monolith was used as column-type fixed bed catalyst for continuous flow hydrogenation of styrene and selective hydrogenation of 3-hexyn-1-ol, in each case without a significant decrease of the catalytic activity after several hours or days. Conversion, selectivity, and stereoselectivity of the alkyne hydrogenation can be tuned by flow rates of hydrogen and the substrate solution, leading to high productivity (1.57 mol g(Pd)-1 h-1) of the corresponding cis-alkene.
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61
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Shizu K, Miwa T, Wada Y, Ogata I, Kaji H. Thermally Activated Delayed Fluorescence Emitter with a Symmetric Acceptor-Donor-Acceptor Structure. J PHOTOPOLYM SCI TEC 2017. [DOI: 10.2494/photopolymer.30.475] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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62
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Uratani H, Kubo S, Shizu K, Suzuki F, Fukushima T, Kaji H. Detailed analysis of charge transport in amorphous organic thin layer by multiscale simulation without any adjustable parameters. Sci Rep 2016; 6:39128. [PMID: 28000728 PMCID: PMC5175281 DOI: 10.1038/srep39128] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 11/17/2016] [Indexed: 11/17/2022] Open
Abstract
Hopping-type charge transport in an amorphous thin layer composed of organic molecules is simulated by the combined use of molecular dynamics, quantum chemical, and Monte Carlo calculations. By explicitly considering the molecular structure and the disordered intermolecular packing, we reasonably reproduce the experimental hole and electron mobilities and their applied electric field dependence (Poole–Frenkel behaviour) without using any adjustable parameters. We find that the distribution of the density-of-states originating from the amorphous nature has a significant impact on both the mobilities and Poole–Frenkel behaviour. Detailed analysis is also provided to reveal the molecular-level origin of the charge transport, including the origin of Poole–Frenkel behaviour.
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63
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Shimizu T, Kanamori K, Maeno A, Kaji H, Nakanishi K. Transparent Ethylene-Bridged Polymethylsiloxane Aerogels and Xerogels with Improved Bending Flexibility. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:13427-13434. [PMID: 27993023 DOI: 10.1021/acs.langmuir.6b03249] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Transparent, monolithic aerogels with nanosized colloidal skeletons have been obtained from a single precursor of 1,2-bis(methyldiethoxysilyl)ethane (BMDEE) by adopting a liquid surfactant and a two-step process involving strong-acid, followed by strong-base, sol-gel reactions. This precursor BMDEE forms the ethylene-bridged polymethylsiloxane (EBPMS, O2/2(CH3)Si-CH2CH2-Si(CH3)O2/2) network, in which each silicon has one methyl, two bridging oxygens, and one bridging ethylene, exhibiting an analogous structure to that of the previously reported polymethylsilsesquioxane (PMSQ, CH3SiO3/2) aerogels having one methyl and three bridging oxygen atoms. Obtained aerogels consist of fine colloidal skeletons and show high visible-light transparency and a flexible deformation behavior against compression without collapse. Similar to the PMSQ aerogels, a careful tuning of synthetic conditions can produce low-density (0.19 g cm-3) and highly transparent (76% at 550 nm, corresponding to 10 mm thick samples) xerogels via ambient pressure drying by solvent evaporation due to their high strength and resilience against compression. Moreover, EBPMS aerogels exhibit higher bending strength and bending strain at break against the three-point bending mode compared to PMSQ aerogels. This improved bendability is presumably derived from the introduced ethylene-bridging parts, suggesting the potential for realizing transparent and bendable aerogels in such polysiloxane materials with organic linking units.
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64
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Nishimura H, Fukushima T, Wakamiya A, Murata Y, Kaji H. The Influence of Quasiplanar Structures of Partially Oxygen-Bridged Triphenylamine Dimers on the Properties of Their Bulk Films. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2016. [DOI: 10.1246/bcsj.20160031] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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65
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Asakura T, Yazawa K, Horiguchi K, Suzuki F, Nishiyama Y, Nishimura K, Kaji H. Difference in the structures of alanine tri- and tetra-peptides with antiparallel β-sheet assessed by X-ray diffraction, solid-state NMR and chemical shift calculations by GIPAW. Biopolymers 2016; 101:13-20. [PMID: 23526402 DOI: 10.1002/bip.22241] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 01/23/2013] [Accepted: 03/07/2013] [Indexed: 11/09/2022]
Abstract
Alanine oligomers provide a key structure for silk fibers from spider and wild silkworms.We report on structural analysis of L-alanyl-L-alanyl-L-alanyl-L-alanine (Ala)4 with anti-parallel (AP) β-structures using X-ray and solid-state NMR. All of the Ala residues in the (Ala)4 are in equivalent positions, whereas for alanine trimer (Ala)3 there are two alternative locations in a unit cell as reported previously (Fawcett and Camerman, Acta Cryst., 1975, 31, 658-665). (Ala)4 with AP β-structure is more stable than AP-(Ala)3 due to formation of the stronger hydrogen bonds. The intermolecular structure of (Ala)4 is also different from polyalanine fiber structure, indicating that the interchain arrangement of AP β-structure changes with increasing alanine sequencelength. Furthermore the precise (1)H positions, which are usually inaccesible by X-ray diffraction method, are determined by high resolution (1)H solid state NMR combined with the chemical shift calculations by the gauge-including projector augmented wave method.
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66
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Shizu K, Kaji H. Organic Electroluminescent Materials Realizing Efficient Conversion from Electricity to Light. J PHOTOPOLYM SCI TEC 2016. [DOI: 10.2494/photopolymer.29.305] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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67
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Suzuki K, Kubo S, Shizu K, Fukushima T, Wakamiya A, Murata Y, Adachi C, Kaji H. Triarylboron-Based Fluorescent Organic Light-Emitting Diodes with External Quantum Efficiencies Exceeding 20 . Angew Chem Int Ed Engl 2015; 54:15231-5. [PMID: 26563845 DOI: 10.1002/anie.201508270] [Citation(s) in RCA: 164] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 10/19/2015] [Indexed: 11/07/2022]
Abstract
Triarylboron compounds have attracted much attention, and found wide use as functional materials because of their electron-accepting properties arising from the vacant p orbitals on the boron atoms. In this study, we design and synthesize new donor-acceptor triarylboron emitters that show thermally activated delayed fluorescence. These emitters display sky-blue to green emission and high photoluminescence quantum yields of 87-100 % in host matrices. Organic light-emitting diodes using these emitting molecules as dopants exhibit high external quantum efficiencies of 14.0-22.8 %, which originate from efficient up-conversion from triplet to singlet states and subsequent efficient radiative decay from singlet to ground states.
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68
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Suzuki K, Kubo S, Shizu K, Fukushima T, Wakamiya A, Murata Y, Adachi C, Kaji H. Triarylboron-Based Fluorescent Organic Light-Emitting Diodes with External Quantum Efficiencies Exceeding 20 %. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201508270] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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69
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Shizu K, Lee J, Tanaka H, Nomura H, Yasuda T, Kaji H, Adachi C. Highly efficient electroluminescence from purely organic donor–acceptor systems. PURE APPL CHEM 2015. [DOI: 10.1515/pac-2015-0301] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractThermally activated delayed fluorescence (TADF) emitters are third-generation electroluminescent materials that realize highly efficient organic light-emitting diodes (OLEDs) without using rare metals. Here, after briefly reviewing the principles of TADF and its use in OLEDs, we report a sky-blue TADF emitter, 9-(4-(benzo[d]thiazol-2-yl)phenyl)-N3,N3,N6,N6-tetraphenyl-9H-carbazole-3,6-diamine (DAC-BTZ). DAC-BTZ is a purely organic donor–acceptor-type molecule with a small energy difference between its lowest excited singlet state and lowest triplet state of 0.18–0.22 eV according to fluorescence and phosphorescence spectra of a DAC-BTZ-doped film. In addition, the doped film exhibits a high photoluminescence quantum yield of 0.82. Time-resolved photoluminescence measurements of the doped film confirm that DAC-BTZ emits TADF. An OLED containing DAC-BTZ as an emitter exhibits a maximum external quantum efficiency (EQE) of 10.3%, which exceeds those obtained with conventional fluorescent emitters (5–7.5%). TADF from DAC-BTZ makes a large contribution to the high EQE of its OLED.
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70
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Ohtsuki A, Lei L, Tanishima M, Goto A, Kaji H. Photocontrolled Organocatalyzed Living Radical Polymerization Feasible over a Wide Range of Wavelengths. J Am Chem Soc 2015; 137:5610-7. [DOI: 10.1021/jacs.5b02617] [Citation(s) in RCA: 191] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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71
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Sagara Y, Shizu K, Tanaka H, Miyazaki H, Goushi K, Kaji H, Adachi C. Highly Efficient Thermally Activated Delayed Fluorescence Emitters with a Small Singlet–Triplet Energy Gap and Large Oscillator Strength. CHEM LETT 2015. [DOI: 10.1246/cl.141054] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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72
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Asakura T, Ohata T, Kametani S, Okushita K, Yazawa K, Nishiyama Y, Nishimura K, Aoki A, Suzuki F, Kaji H, Ulrich AS, Williamson MP. Intermolecular Packing in B. mori Silk Fibroin: Multinuclear NMR Study of the Model Peptide (Ala-Gly)15 Defines a Heterogeneous Antiparallel Antipolar Mode of Assembly in the Silk II Form. Macromolecules 2014. [DOI: 10.1021/ma502191g] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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73
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Abe K, Hayato Y, Iida T, Iyogi K, Kameda J, Koshio Y, Kozuma Y, Marti L, Miura M, Moriyama S, Nakahata M, Nakayama S, Obayashi Y, Sekiya H, Shiozawa M, Suzuki Y, Takeda A, Takenaga Y, Ueno K, Ueshima K, Yamada S, Yokozawa T, Ishihara C, Kaji H, Kajita T, Kaneyuki K, Lee KP, McLachlan T, Okumura K, Shimizu Y, Tanimoto N, Labarga L, Kearns E, Litos M, Raaf JL, Stone JL, Sulak LR, Goldhaber M, Bays K, Kropp WR, Mine S, Regis C, Renshaw A, Smy MB, Sobel HW, Ganezer KS, Hill J, Keig WE, Jang JS, Kim JY, Lim IT, Albert JB, Scholberg K, Walter CW, Wendell R, Wongjirad TM, Ishizuka T, Tasaka S, Learned JG, Matsuno S, Smith SN, Hasegawa T, Ishida T, Ishii T, Kobayashi T, Nakadaira T, Nakamura K, Nishikawa K, Oyama Y, Sakashita K, Sekiguchi T, Tsukamoto T, Suzuki AT, Takeuchi Y, Ikeda M, Minamino A, Nakaya T, Fukuda Y, Itow Y, Mitsuka G, Tanaka T, Jung CK, Lopez GD, Taylor I, Yanagisawa C, Ishino H, Kibayashi A, Mino S, Mori T, Sakuda M, Toyota H, Kuno Y, Yoshida M, Kim SB, Yang BS, Okazawa H, Choi Y, Nishijima K, Koshiba M, Yokoyama M, Totsuka Y, Martens K, Schuemann J, Vagins MR, Chen S, Heng Y, Yang Z, Zhang H, Kielczewska D, Mijakowski P, Connolly K, Dziomba M, Thrane E, Wilkes RJ. Search for nucleon decay via n→ν[over ¯]π0 and p→ν[over ¯]π+ in Super-Kamiokande. PHYSICAL REVIEW LETTERS 2014; 113:121802. [PMID: 25279622 DOI: 10.1103/physrevlett.113.121802] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Indexed: 06/03/2023]
Abstract
We present the results of searches for nucleon decay via n→ν[over ¯]π0 and p→ν[over ¯]π+ using data from a combined 172.8 kt·yr exposure of Super-Kamiokande-I,-II, and-III. We set lower limits on the partial lifetime for each of these modes: τn→ν[over ¯]π0>1.1×10(33) years and τp→ν[over ¯]π+>3.9×10(32) years at a 90% confidence level.
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Lei L, Tanishima M, Goto A, Kaji H, Yamaguchi Y, Komatsu H, Jitsukawa T, Miyamoto M. Systematic Study on Alkyl Iodide Initiators in Living Radical Polymerization with Organic Catalysts. Macromolecules 2014. [DOI: 10.1021/ma501569j] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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75
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Hayase G, Kanamori K, Abe K, Yano H, Maeno A, Kaji H, Nakanishi K. Polymethylsilsesquioxane-cellulose nanofiber biocomposite aerogels with high thermal insulation, bendability, and superhydrophobicity. ACS APPLIED MATERIALS & INTERFACES 2014; 6:9466-71. [PMID: 24865571 DOI: 10.1021/am501822y] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Polymethylsilsesquioxane-cellulose nanofiber (PMSQ-CNF) composite aerogels have been prepared through sol-gel in a solvent containing a small amount of CNFs as suspension. Since these composite aerogels do not show excessive aggregation of PMSQ and CNF, the original PMSQ networks are not disturbed. Composite aerogels with low density (0.020 g cm(-3) at lowest), low thermal conductivity (15 mW m(-1) K(-1)), visible light translucency, bending flexibility, and superhydrophobicity thus have been successfully obtained. In particular, the lowest density and bending flexibility have been achieved with the aid of the physical supporting effect of CNFs, and the lowest thermal conductivity is comparable with the original PMSQ aerogels and standard silica aerogels. The PMSQ-CNF composite aerogels would be a candidate to practical high-performance thermal insulating materials.
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