Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Symmetric and highly asymmetric polystyrene- block -polyisoprene- block -polystyrene (SIS triblock) copolymers were synthesized via sequential anionic polymerization using difunctional initiator, and symmetric and highly asymmetric polystyrene- block -polyisoprene (SI diblock) copolymers were also synthesized using mo…
Narrow distribution macrocyclic poly(9,9-dimethyl-2-vinylfluorene) (PDMVF) and the matching linear precursors with the same degree of polymerization (DP n from 12 to 145) were synthesized via anionic polymerization followed by the end-to-end coupling with 1,4-bis(bromomethyl)benzene (DBX) or 9,10-bis(chloromethyl)anth…
Low-temperature phosphorescence (LTP) decay measurements have been carried out in wild-type Escherichia coli alkaline phosphatase (AP), metal-depleted AP (apoAP), and terbium-substituted AP (TbAP) at 77, 4.2, and 1.2 K. Over this temperature range, Tb emission monitored at 542.4 nm decays with two apparent lifetime co…
Quasielastic light scattering measurements were performed in the nematic phase of mixtures consisting of the calamitic mesogen 8OCB doped with small concentrations of the bent-core molecule P-7PIMB. It was found that the regular part of the bend elastic constant decreases strongly with dopant concentration X. Close to…
The application of Raman spectroscopy to the study of the copper chloride minerals nantokite, eriochalcite and claringbullite has enabled the vibrational modes for the CuCl, CuOH and CuOH 2 to be determined.Nantokite is characterised by bands at 205 and 155 cm -1 attributed to the transverse and longitudinal optic vib…
An investigation was carried out on the effect of molecular architecture on the dynamics of multigraft (MG) copolymers of polyisoprene (PI) and polystyrene (PS). MG copolymers with regularly spaced multiple grafts with trifunctional (combs), tetrafunctional (centipedes), and hexafunctional (barbwires) branch points we…
Biomimetics is seen as a path from biology to engineering. The only path from engineering to biology in current use is the application of engineering concepts and models to biological systems. However, there is another pathway: the verification of biological mechanisms by manufacture, leading to an iterative process b…
Low-molecular-weight poly(ethylene oxide) (PEO) was grafted onto high-surface-area (A380) fumed silica (SiO 2 ) by the use of a silane coupling agent, (CH 3 O) 3 −Si−(CH 2 ) 3 −(OCH 2 CH 2 ) x −OCH 3, with x = 6−9, corresponding to an average molecular weight for the PEO segment of 375 g/mol, PEO(375)−silane. The PEO-…
From dielectric relaxation and equation-of-state measurements on polymethylphenylsiloxane and polymethyltolylsiloxane, the relative contributions of volume and thermal energy to the temperature dependence of the segmental relaxation times are quantified. In both polymers, volume exerts a substantial effect, being almo…
The synthesis of linear multiporphyrin arrays with mono- and bisphosphine-substituted porphyrins as ligand donors and ruthenium(II) or rhodium(III) porphyrins as ligand acceptors is described. With appropriate amounts of the building blocks mixed, linear dimeric and trimeric arrays have been synthesized and analyzed b…
Mo K-edge XAFS spectra have been measured for ordered mesoporous silica MCM-41 grafted with the complexes [MoO2X2(thf)2] (X=Cl, Br). For grafting reactions in the absence of triethylamine, materials with 1 wt. % Mo are obtained; the Mo K-edge EXAFS results indicate the co-existence of isolated surface-fixed monomeric…
A highly birefringent, luminescent chiral nematic liquid crystal is shown to have an extremely broad photonic stop band (see dashed line in Figure) overlapping its emission spectrum. Highly circularly polarized photoluminescence is observed from the liquid crystal itself and from an indirectly excited dye dopant. The…
Periodic density functional calculations using pseudopotentials and a local basis set were performed on the type I clathrates A(8)Ga(16)Ge(30) (A=Sr, Ba). Both are known to show promising thermoelectric properties. Ab initio wave functions were analyzed within the framework of the quantum theory of atoms in molecules.…
Reduction of the dielectric constant k to the ultra low‐ k range is important for the continuing miniaturization of semiconductor devices. It is demonstrated that γ‐cyclodextrin can act as an effective porogen (see Figure) to reduce k while maintaining good film strength. A continuous thin pure‐silica zeolite MFI film…
A family of five metallodendrimers with pentamethylamidoferrocenyl termini were synthesized from the DSM dendrimers G(n)-DAB-dend-(NH(2))(x) (x=4, 8, 16, 32, 64) and characterized by standard techniques, including prominent molecular peaks (broad for x=64) in their MALDI-TOF mass spectra. Oxidation of G(4)-DAB-dend-(N…
The mixed-ligand complexes [Co(III)(tpy)(Cat-N-SQ)]Y and [Ni(II)(tpy)(Cat-N-BQ)]PF(6) (tpy = 2,2':6',2' '-terpyridine; Cat-N-BQ, Cat-N-SQ = mononegative and radical dinegative Schiff base diquinone ligand; Y = PF(6), BPh(4)) were prepared. Structural and spectroscopic data support the different charge distribution of…
Electrochemical coating of individual single‐walled carbon nanotubes (SWCNTs) with thin films obtained via oxidative coupling of an amine or reductive coupling of an aromatic diazonium salt is reported. The same SWCNTs have been characterized before and after modification by electrical transport measurements and confo…
Vanadium oxide hydrate has been used in a new, robust, and inexpensive shape‐templating synthesis leading to silica nanotubes (SiO 2 ‐NTs, see Figure) with good chemical purity, a well‐defined morphology, and high aspect ratio. Unidimensional nanosized cavities or channels are made accessible through the open ends of…
In this paper, we report on in situ optical/electrochemical investigations using a combination of surface plasmon resonance spectroscopy and electrochemistry in order to determine the complex dielectric constants of poly(3,4-ethylenedioxythiophene) (PEDOT) thin films. The PEDOT films were deposited by in situ electrop…
The perovskite-related crystal structure of the compound Sr 0.7 Y 0.3 CoO 2.62 was determined and refined using synchrotron X-ray and neutron powder diffraction, in space group I 4/ mmm, a = 7.6237(8) Å and c = 15.314(2) Å, to R I = 0.041 in the synchrotron data set. It contains layers of CoO 6 octahedra, perpendicula…