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。
We have experimentally determined a phase diagram for cylinder-forming polystyrene-block-polybutadien-block-polystyrene triblock copolymer in thin films. The phase behavior can be modeled in great detail by dynamic density functional theory. Deviations from the bulk structure, such as wetting layer, perforated lamella…
Ethylene–vinylcyclohexane copolymers (EVCH) were synthesized with unsubstituted and substituted bis-indenyl type metallocene catalysts and their thermal and dynamic mechanical behavior was studied and compared to a series of metallocene catalyzed ethylene-1-hexene (EH) and ethylene-1-hexadecene (EHD) copolymers. Incre…
Electrocrystallization of the novel π-electron donor (ethylenethio)(ethylenedithio)tetrathiafulvalene (ETEDT-TTF) with trihalide anions has given rise to a new family of radical cation salts with insulating properties, [ETEDT-TTF]X, and conducting properties, ETEDT-TTF]X 0.42, where X = I 3 - or I y Br 3 - y - . Accor…
The synthesis and characterization of novel organometallic polyphenylene dendrimers containing 24 or 44 phenyl rings and one cyclobutadiene(cyclopentadienyl)cobalt unit is reported. The dendrimers are made by the convergent CpCo(CO)(2)-mediated dimerization of di- or tetraethynyltolanes followed by a divergent core ex…
We report the first solution state circular dichroism (CD) spectroscopic properties of a newly designed polyfluorene (PF) featuring highly enantiopure β-branched chiral alkyl side chains, poly[2,7-{9,9-bis[( S )-2-methyloctyl]}fluorene] (PFMO), in dilute THF solution. Upon cooling the solution temperature, the single…
A solvent-free photooxygenation process that uses organic substrates embedded in porphyrin-loaded polystyrene beads as solid support is described and applied for ene- and [4 + 2]-cycloaddition reactions involving singlet oxygen (1 delta g).
Well-defined fluorene oligomers (n = 1 to 6) were prepared step by step using Suzuki and Yamamoto couplings, while absorption and photoluminescence properties evidenced very large dipolar coupling interactions between fluorene moieties.
Theoretical calculations of the NO 2 adsorption on transition metal−exchanged zeolite (metal = Cu, Ag, Au) were carried out using density functional theory and MP2 approaches. A tritetrahedral model (T3) was used to represent a fragment of a zeolite. The density functional calculations predict that the NO 2 adsorption…
Histamine, an ubiquitous cell-to-cell messenger, was identified in 1910 by Dale and Laidlaw (1) and has been recognized since the 1920s as a major mediator of allergic disorders such as rhinitis, asthma, urticaria, and anaphylaxis. The precise mechanism of action of histamine remained unknown until 1966, when the H1his…
We have studied the adsorption of mercury vapor to gold and silver surfaces by surface plasmon resonance spectroscopy. Three types of metal films were studied including 50 nm Au, 50 nm Ag, and Au-coated silver films (15 nm Au/35 nm Ag). The sensitivity of each substrate for Hg detection was determined by quantitative…
Two new three-dimensional oxychlorides are reported, Te(4)M(3)O(15).Cl (M = Nb(5+) or Ta(5+)). The isostructural materials were synthesized by chemical transport reactions utilizing TeO(2), M(2)O(5), and MCl(5) (M = Nb(5+) or Ta(5+)) as reagents. The compounds exhibit a three-dimensional cationic tunnel framework, wit…
Hydroquinone was chosen as an electroactive probe to study the β-cyclodextrin (β-CD) modified poly( N -acetylaniline) (PNAANI) electrode. The β-CD modified PNAANI electrode was prepared by electrooxidation of the PNAANI electrode in a β-CD/DMSO solution. The electrochemical properties of the β-CD inclusion complex of…
The role of oil spreading in the process of foam destruction by oil-based antifoams (oils or mixed oil−solid compounds) has been the subject of a long debate in the literature. To clarify some aspects of this problem, we compare the entry barriers of antifoam globules in the presence and in the absence of a prespread…
Molecular dynamics simulations, integral equation theory, and wide-angle X-ray scattering experiments are used to study the structure of a poly(dimethylsiloxane) (PDMS) melt. Two different chain models are employed for the molecular dynamics: a united-atom class I potential and an explicit-atom class II potential. The…
Abstract Small‐angle X‐ray scattering (SAXS), atomic force microscopy (AFM), and other techniques were combined in a study of segmented thermoplastic elastomers (Pebax) containing poly(tetramethylene oxide) soft segments and hard blocks of nylon‐12. AFM was used to provide real‐space resolution of the morphology durin…
Recently, a new set of clusters in which twelve Si atoms encapsulate one transition metal atom were found to be especially stable. Making use of $M{\mathrm{Si}}_{12}$ clusters $(M=\mathrm{N}\mathrm{b},\mathrm{W})$ we carry out a first-principles study of the possibility of synthesizing a crystalline phase using such c…
Temperature-dependent reflection−absorption Fourier transform infrared spectra of poly(methyl methacrylate) (PMMA) thin films were measured. From these spectra, two-dimensional (2D) maps of the first derivative of the absorbance with respect to temperature over the space of wavenumber and temperature were constructed.…
In situ x-ray diffraction and Raman spectroscopy were used to explore the pressure-induced phase transformation of spinel ${\mathrm{Zn}}_{2}{\mathrm{TiO}}_{4}$ to pressures of 52.4 and 81.1 GPa, respectively. Results indicate that spinel ${\mathrm{Zn}}_{2}{\mathrm{TiO}}_{4}$ initially transforms to the orthorhombic $(…
BaMgAl 10 O 17:Eu 2+ phosphor powder was synthesized using a sol−gel process. Doping Er 3+ and Nd 3+ in the phosphor can increase the luminescent intensity of the phosphor in the VUV region. The BaMgAl 10 O 17:Eu 2+ phosphor crystallizes completely when the dried gel is calcined at 1300 °C. The BaMgAl 10 O 17:Eu 2+ ca…
Polystyrene latex particles carrying silanol groups on their surface have been synthesized in emulsion polymerization using 3-(trimethoxysilyl)propyl methacrylate (MPS) as a functional comonomer. We showed that the colloidal stability of the resulting latex suspensions was highly dependent on pH and on the nature of t…