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。
Samples of poly(2,2‘-dioxybiphenylphosphazene) were prepared according to procedures previously reported in the literature and submitted to thermal degradation at temperatures between 100 and 200 °C during periods of time ranging from 6 to 250 h. Experimental characterization of the parent polymer and the degraded sam…
Variable-temperature FTIR measurements were performed on amorphous films of isotactic and syndiotactic PMMA, followed by a detailed analysis of the temperature dependence of integrated band intensities for C−O stretching modes in the region 1050−1300 cm -1 . The use of computerized FTIR instrumentation and modern meth…
In the present study we examined the oxygen-transport properties of poly(ethylene naphthalate) (PEN) isothermally crystallized from the melt (melt crystallization) or quenched to the glass and subsequently isothermally crystallized by heating above the glass transition temperature (cold crystallization). The gauche /…
The packing of binary and polydisperse unimodal and bimodal ensembles of hard spheres in the limit of high pressure is studied using a sequential addition algorithm. Upon fixing the number of particles, and their size distribution, the average (maximum) packing fraction is determined for systems of up to 20 000 partic…
Active sites for photometathesis on mesoporous silica materials, FSM-16 and MCM-41, and amorphous silica, which are generated by dehydroxylation of surface isolated hydroxyl groups at high temperature above 673 K, were investigated by some spectroscopies such as FTIR, ESR, VUV−UV, and photoluminescence. FTIR study rev…
Random copolymers of methyl methacrylate with polyhedral oligomeric silsesquioxane (POSS) were synthesized and blended with PS and PMMA homopolymer thin films. The effects of the POSS on phase segregation were studied using a variety of complementary techniques. The results showed that these copolymers were efficient…
A systematic approach is developed for the in situ control of the crystal size distribution, and is applied to the aqueous crystallization of paracetamol (acetaminophen) as a model pharmaceutical system. This involves the determination of the solubility curve and the metastable limit, and the operation of concentratio…
The classical Cahn-Hoffman capillarity vector formalism for anisotropic interfaces, widely used to analyze capillary and surface patterning processes in metallurgical systems, is applied to nematic liquid crystalline interfaces. The nematic capillarity vector is derived and expressed in terms of nematic surface energi…
Liquid metals such as gallium, tin and lithium are potential plasma-facing materials that may be used to withstand the high heat and particle fluxes in a fusion plasma environment. The interaction of plasma with liquid gallium surfaces has been examined experimentally because of the liquid's wide temperature range (30…
The structural changes occurring along the necked region developed when amorphous poly(ethylene naphthalate) (PEN) films are cold drawn were investigated by means of X-ray microdiffraction using synchrotron radiation. The wide-angle X-ray scattering (WAXS) results reveal the appearance of smectic order with a period o…
The thy1 gene of Thermotoga maritima encodes a thymidylate synthase-complementing protein with a molecular weight of 26,005 Da and a predicted isoelectric point of 8.2. Thymidylate synthase complementing proteins (TSCP) have been implicated in cell survival in the absence of external sources of thymidylate.1 The mecha…
New polymer/inorganic hybrid materials have been prepared by a two-step soft chemistry route including the intercalation of aniline sulfonic acid between the sheets of a layered double hydroxide (LDH), Cu 2 Cr(OH) 6 Cl·nH 2 O, and its in situ polymerization at temperatures below 473 K in air atmosphere. A combination…
It is usually assumed that the Flory−Huggins interaction parameter χ in polymer blends can be represented by a structureless, pointlike interaction. On a local scale, however, the Flory−Huggins parameter must show a spatial dependence as it basically reflects the segment−segment interaction potential. We show that SAN…
Electronic absorption and magnetic circular dichroism (MCD) spectra of 2,3,6,7,11,12,17,18-octaethylcorrphycene, a constitutional isomer of porphyrin, were recorded for the neutral, doubly protonated, and doubly deprotonated forms. The spectra closely resemble those of the parent porphyrin and are quite different from…
The heteropoly compound [(V(V)O(4))Mo(VI)(12)O(36)(V(IV)O)(6)][(OH)(9)].11H(2)O (1), synthesized by hydrothermal method under weak basic conditions, represents the first mixed Mo/V six-capped Keggin structural derivative with a spherical skeleton, and the first transition metal polyoxocation. The successful synthesis…
Equilibrium contact angles are reported for silicone oils (poly(dimethylsiloxane)s) on polymer-coated and uncoated solid-silicon substrates immersed in aqueous electrolyte solutions. Solid-substrate wettability to water ranges from highly hydrophilic to highly hydrophobic based on water/air contact angles. Although si…
We have investigated the electronic structure of the commensurate charge-density-wave (CDW) phase for $1T\ensuremath{-}{\mathrm{TaSe}}_{2}$ by Ta $4f$ core-level and the angle-resolved photoemission. From the energy shifts of Ta $4f$ core levels due to a CDW formation, it is found that the CDW amplitude in the $1T\ens…
Herein we describe the preparation of intrinsically conducting poly(thiophene) via two different routes: solution- and solid-state cross-linking of terthiophene moieties. The solution-state cross-linking of terthiophene moieties was performed using conventional electrochemical polymerization in which insoluble cross-l…
The solvent viscosity effect on photochromic reaction processes such as cyclization and cycloreversion of a diarylethene derivative, 2-bis(2,4,5-trimethyl-3-thienyl)maleic anhydride (TMTMA), was investigated by means of steady-state spectroscopy, picosecond transient absorption, and fluorescence measurements. The cycl…
Starting from mesoporous V 2 O 5 containing a small amount of Mg, V 2 O 5 /PANI (polyaniline) nanocomposites with lamellar and wormlike structures and fibrous morphologies were synthesized. Mesoporous V 2 O 5 /Mg was first prepared at room temperature using a binary mixture of surfactants (cetyltrimethylammonium bromi…