Synthesis and characterization of mesoporous SAPO
Self-assembled ordered cetyltrimethylammonium bromide (CTAB) is used as a template for the synthesis of mesoporous silicoaluminophosphates with varying Si/Al ratio.
Materials Literature
文献浏览
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。
Mode-coupling theory of the slow dynamics of polymeric liquids: Fractal macromolecular architectures
Recently a mode coupling theory for the dynamics of solutions and melts of entangled linear chain polymers has been developed. We report the extension of this approach to macromolecular architectures different from linear chains. Specifically, this work addresses recent experimental findings on melts of ring shaped po…
Preparation and characterization of porous silica spheres by the sol–gel method in the presence of tartaric acid
Millimetre-sized mesoporous silica spheres, the sizes of which could be controlled by the mixing speed of the preparation solution, have been prepared directly from the reaction of tetraethoxysilane with tartaric acid in cyclohexanol by the sol–gel process. The silica gel spheres calcined at 400 °C showed specific sur…
Synthesis, Characterization, and Magnetic Studies of Two Novel Isostructural Pentanuclear Iron(II) Complexes
The synthesis, X-ray structural characterization, and Mössbauer and magnetic properties of the two pentanuclear complexes [Fe 5 (μ 3 -F) 2 (XDK) 2 (L) 4 (O 2 CPh) 4 ], where L = pyridine (py) or N -methylimidazole ( N -MeIm), are described. Reaction of [Fe(H 2 O) 6 ](BF 4 ) 2, the deprotonated dinucleating dicarboxyla…
Methyltrioxorhenium supported on silica tethered with polyethers as catalyst for the epoxidation of alkenes with hydrogen peroxide
Methyltrioxorhenium has been supported on silica functionalized with polyether tethers; in the absence of an organic solvent, this catalytic assembly catalysed the epoxidation of alkenes with 30% aqueous H2O2 in high selectivity compared to the ring opening products observed in homogeneous media.
Catalytic activity of FSM-16 for photometathesis of propene
Mesoporous silica (FSM-16) catalyses metathesis of propene under photoirradiation at a higher activity than amorphous silica whereas microporous silica crystals (silicalite-1) do not catalyse the reaction.
The Formation of Black Patina on Copper in Humid Air Containing Traces of SO 2
The formation of a black patina on copper in humid air containing traces of SO 2 was investigated using on‐line analysis of SO 2 and corrosion product characterization (x‐ray photoelectron spectroscopy, Fourier transform infrared absorption spectroscopy, x‐ray diffraction, and quantitative analysis of sulfite). In hum…
CVD preparation and characterization of tin dioxide films for electrochemical applications
SnO 2 films have been succesfully prepared by chemical vapour deposition (CVD) by reaction of SnCl 2 with O 2 and a value of the activation energy of 58 kJ mol -1 has been measured. The temperature range 450–500 °C has been found to be the optimum for the reaction with resistivities of the films of 9×10 -4 Ω cm on sil…
Induction of Liquid Crystallinity by Host−Guest Interactions
A molecular clip is described which binds aromatic guests by an induced fit mechanism. It contains twelve long aliphatic chains and can evoke liquid-crystalline properties in a variety of molecules, including polymers and porphyrins, by a process of molecular recognition.
Statistical comparison between dissolution profiles of drug products
The problem for assessment of similarity between dissolution profiles of two drug products is considered. The commonly used classical methods including model-dependent and model-independent approaches are reviewed. Most methods encountered the difficulties of no well-defined equivalence limits and the correlation betw…
Characterization and optical properties of gold nanoparticles dispersed in nylon 11 thin films
We have prepared nylon 11 thin films containing individually isolated Au particles with various volume fractions ranging from 1.7 to 8.3% by means of a consecutive evaporation followed by heat treatment. The films obtained were characterized by TEM, XPS and UV–VIS absorption spectroscopy. Au particles were homogeneous…
A conjugated polymer/redox polymer hybrid with electronic communication between metal centres
Enhanced electrochemical charge transport rates in a conjugated metallopolymer formed by complexation of [Ru(2,2′-bpy) 2 ] 2+ moieties to donor N-atoms in the backbone of a benzimidazole-based polymer provide strong evidence for electronic communication between metal centres.
Reorientation of Nematic Liquid-Crystals and Liquid-Crystalline Polymers in an Electric Field Studied by FT-IR Time-Resolved Spectroscopy and 2D-Correlation Analysis
Fourier-transform infared (FT-IR) time-resolved spectroscopy was used to study the segmental mobility of two low molecular weight nematic liquid-crystals ( p -cyanophenyl p -( n -hexyl)benzoate, 6CPB, p -cyanophenyl p -( n -heptyl)benzoate, 7CPB) and a nematic liquid crystalline polymer (poly[ p -( n -hexyl)( p -(cyan…
Characterization of the Fe-Al Inhibition Layer Formed in the Initial Stages of Hot-dip Galvannealing.
Due to the lack of detailed information surrounding the inhibition phenomenon in hot-dip galvannealing, and the microstructure and morphology of the Fe-Al inhibition compounds, this study was initiated to investigate the inhibition layer formed under the low bath Al content, short-dipping-time conditions typical of co…
Phase I and pharmacokinetic study of tirapazamine (SR 4233) administered every three weeks.
Tirapazamine (SR 4233; 3-amino-1,2,4-benzotriazine-1,4-di-N-oxide) is a bioreductive agent exhibiting up to 200 x greater toxicity for hypoxic cells as compared to oxygenated cells. In murine studies, a selective increase in tumor kill was observed when tirapazamine was coadministered with other agents, notably cispla…
NMe4V3O7: critical role of pH in hydrothermal synthesis of vanadium oxides
pH is critical in the formation of new mixed-valence vanadium oxides, NMe 4 V 3 O 7 , NMe 4 V 4 O 10 and the dioxide Li x V 2 O 4 ·H 2 O, with NMe 4 + cations or water molecules residing between vanadium oxide layers.
Ferroelectric phase transition in deuterated glycinium phosphite crystals
The dielectric permittivity between 500 Hz and 1 GHz and pyroelectric properties of (${\mathrm{ND}}_{3}$ ${\mathrm{CH}}_{2}$ COOD)${\mathrm{D}}_{2}$ ${\mathrm{PO}}_{3}$ (DGPI) single crystals in the vicinity of ferroelectric phase transition (322 K) are measured. The spontaneous polarization along the b axis is found…
A ferrimagnetically coupled liquid crystal
Ferrimagnetic coupling in a mesogen is reported for the first time for the compound Mn III [((OC 12 H 25 ) 4 TPP)](TCNE) · 2 touluene (where TPP = tetraphenyl porphyrin, TCNE – tetracyanoethylene), which displays liquid crystal properties above 381 K and ferrimagnetic properties below 21.4 K. The results from differen…
Conductive polymers : synthesis and electrical properties
Partial table of contents: Polyacetylene (S. Curran, et al.). Electrically Conductive Polyacetylene Copolymers (L. Leung). Synthesis and Properties of Processable Polythiophenes (K. Kaeriyama). Molecular Conductive Materials: Polythiophenes and Oligothiophenes (S. Hotta). Polythiophene and Polypyrrole Copolymers (R. G…
Analysis of the Modeling Methodologies for Predicting the Strength of Air-Jet Spun Yarns
The scope, usability, limitations and predictive power of four modeling methodologies are analyzed in this paper: mathematical models, empirical models, computer simulation models, and artificial neural network models. The predictive power of each of the four is estimated by comparing predicted yarn strength with expe…