Materials Literature
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The Current Status of IPNs Phase Separation During Synthesis of Polyetherimide/Epoxy Semi-IPNs A Review of Kinetic Studies on the Formation of IPNs IPNs Based on Polyurethane and Poly(butyl-methacrylate): Interrelation Between Reaction Kinetics and Microphase Structure Latex IPNs: From Structures to Properties Poly(et…
CO chemisorption on Pt catalysts supported on non-acidic alumina prepared from platinum acetylacetonate has been studied by FTIR spectroscopy. The stretching frequency for isolated CO species is observed at 2032 cm−1 for highly dispersed Pt samples (dispersion 0.99) and at 2067 cm−1 for poorly dispersed samples (dispe…
This paper presents nanoscopic aspects of electronic aging in dielectrics, as the result of the interaction of excess non-thermalized carriers with the media. Hot electrons are hypothesized as the major source of non-thermal carriers and shown to be a decisive factor in electrical breakdown. The interaction of hot ele…
BACKGROUND AND OBJECTIVE: Linear birefringence is an anisotropic property of rat tail tendon, which is largely composed of collagen. Our goal is to show that the dynamic range and sensitivity of the linear birefringence loss of collagen during heating are sufficient for kinetic modeling of the reaction. STUDY DESIGN,…
A new, ambient-temperature method for the direct synthesis of organo-substituted polyphosphazenes is described. It involves the initiation of a series of organophosphoranimines R(R‘)XP NSiMe 3 ( 3, R = Ph, R‘ = X = Cl; 5, R = R‘ = Ph, X = Cl; 7, R = Me, R‘ = Et, X = Cl; 9, R = R‘ = CF 3 CH 2 O, X = Br) with catalytic…
Ruthenium porphyrin and porphycene complexes catalyse stereospecific cyclopropanation of styrenes; high product turnovers with up to 90.8% ee were achieved with the [Ru(P*)(CO)(EtOH)] catalyst (H 2 P* = chiral D 4 porphyrin).
The crystal structure of the R-phase was determined by combined use of the electron diffraction and the powder X-ray diffraction method. The Rietveld method was applied for the analysis of the powder diffraction data. The structure of the R-phase belongs to the space group P3 and is similar to that of ζ′2 Au–Cd marten…
Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation Peter Hoppe, Ulrich Ott; Mainstream silicon carbide grains from meteorites. AIP Conference Procee…
The reaction of silica gel with 3-(trimethoxysilyl)propane-1-thiol, MPTS, produced a thiol-modified silica gel, Sil–SH. This material removes silver, mercury, copper, zinc and nickel ions from aqueous solutions. Enthalpy changes that occur in the interactions between Sil–SH and these cations were obtained by a calorim…
Radiation grafted and sulfonated poly(vinylidene fluoride), PVDF, membranes have been studied by thermal analysis and X-ray diffraction to determine the changes in membrane crystallinity and structure during preparation. Commercial PVDF films were irradiated with an electron beam, grafted with styrene and finally sulf…
We have used digital video microscopy to study the equilibrium structure of quasi-two-dimensional suspensions of sterically stabilized uncharged polymethylmethacrylate spheres. The spheres are confined between the surfaces of a very thin glass cell. Our experiments reveal the existence of an equilibrium hexatic phase…
Nature learned long ago how useful proteins are as a diverse set of building blocks to make materials with very diverse properties. Spider webs, egg whites, hair follicles, and skeletal muscles are al
Both spirooxazine and spiropyran dyes have been embedded into two different hybrid matrices, which were formed from hydrolysis and cocondensation between diethoxydimethylsilane and zirconium propoxide and between methyldiethoxysilane (DH) and triethoxysilane (TH) respectively. The nature and the kinetics of the photoc…
The physico-chemical properties of biodegradable polylactide-co-glycolide (PLGA) microspheres containing the peptide salmon calcitonin (sCT) were affected by the processing parameters. The microsphere size increased with an increase in the viscosity of the polymer solution. Concentration of methanol and peptide in the…
Carbon films have been produced on the surface of β-SiC particles by reaction with Ar–Cl 2 and Ar–Cl 2 –H 2 gas mixtures at atmospheric pressure and temperatures of 600–1000 °C. The structure and composition of the carbon films have been investigated using XRD, SEM, EDS, TEM, FTIR and Raman spectroscopy. BET and TG we…
Palladium grafted mesoporous MCM-41 materials, prepared by vapor grafting, show remarkable activity in Heck carbon–carbon coupling reactions.
The suitability fo columnar discotics for applications in light emitting diodes (LEDs) has been investigated following the demonstration of their unusually large charge carrier mobilities. Results of X‐ray diffraction, computer simulations, and electroluminescence measurements are presented and discussed for discotic…
Iron-containing molecules and ions with various types of bonding were calculated using DFT theory (B3LYP functional) and an energy-adjusted effective core potential for iron (ECP(S)). Examination of calculated geometries, bond dissociation energies, ionization energies, enthalpies of formation, and harmonic frequencie…
Crystals of Fe 3 R(BO 3 ) 4 (R = Y, La, Nd) have been grown. Their structure and properties show close relations. The structures of these materials have been established by single-crystal X-ray diffraction. They crystallize in the huntite, CaMg 3 (CO 3 ) 4, structure type, trigonal system, space group R 32 (No. 155),…
Experimental work on charge distributions and charge transport in polymer films is reviewed. For studying the charge distributions in the thickness dimension, thermal or acoustic techniques are used with resolutions down to /spl sim/1 /spl mu/m. The polymer samples usually are charged with corona, electron beam or the…