Materials Literature
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In the reports “Hydrogen storage in single-walled carbon nanotubes at room temperature” by C. Lui et al. (5 Nov., p. [1127][1]) and “High H2 uptake by alkali-doped carbon nanotubes under ambient pressure and moderate temperatures” by P. Chen et al. (2 July, p. [91][2]), the authors make the
The syntheses of the vinyloxycyclotriphosphazene derivatives N3P3X5OCH=CH2 (X = OMe, OCH2CF3) and the N3P3(NMe2)4(OCH=CH2)2 isomeric mixture along with improved preparations of N3P3X5OCH=CH2 (X = F, NMe2) are reported. The interactions between the vinyloxy function and the cyclophosphazene in these and the previously…
Measurements of craze stresses and impact strengths have been performed on specially designed polyestercarbonates with 1,4-cyclohexylene linkages synthesized in our laboratory. The copolymers became more craze resistant as the cyclohexylene content was increased. On the other hand, the activation volumes of these copo…
Concentrations of Al3+ were calculated in soil solutions from concentrations of the monomeric ‘reactive Al’ species ([Al3+] + [Al(OH)2+] + [Al(OH)2+] + [AlF2+]) obtained using a recently reported flow injection analysis (FIA) chelating resin technique. Soil solution samples came from 7 sites encompassing a range of Ne…
Summary The presence of formaldehyde ( 4 ) in solutions of cellulose in N -methylmorpholine- N -oxide (NMMO, 1 ) has been shown by trapping formaldehyde as dimedone adduct 8 in a two-phase system. o -Dichlorobenzene was used as an inert solvent to extract the trapping product as soon as it had formed. Morpholine is a…
Bis(2,2'-bipyridyl)(dioctadecyl-2-[2,2‘-dipyridylmethylene] malonate) ruthenium(II) dihexafluorophosphate has been synthesized and was converted to an amphiphilic distearyl ester, 2b . Light-induced charge transfer from ruthenium to the pyridyl ligands occurred preferably to the malonate-type ligand. Its reduction pot…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTGrafting Rates of Amine-Functionalized Polystyrenes onto Epoxidized Silica SurfacesL. S. Penn, T. F. Hunter, Y. Lee, and R. P. QuirkView Author Information Department of Chemical and Materials Engineering, University of Kentucky, Le…
Four dyes (2-DASPI, 4-DASPI, LDS698, and LDS722) derived from the stilbazolium skeleton have been intercalated into optically transparent Na−fluorine mica layers. X-ray diffraction data show that the long axis of DASPI dyes is aligned parallel to the layer, largely maintaining their solution phase structure. On the ot…
The oxidation of sulfides and sulfoxides by permanganate in anhydrous acetone solutions is catalyzed by Lewis acids such as iron(III) chloride, zinc chloride, and mercury(II) chloride. The reaction kinetics unequivocally confirm that the function of these catalysts is to activate the oxidant by forming permanganate/Le…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTWater-Soluble Self-Doped Conducting Polyaniline CopolymerWusheng Yin and Eli RuckensteinView Author Information Department of Chemical Engineering, State University of New York at Buffalo, Buffalo, New York 14260 Cite this: Macromol…
Hyperbranched polyglycerols (DP n = 23−83; M w / M n = 1.2−1.5) as well as their propoxylated derivatives were esterified to different extents (23%−100%) with various carboxylic acids (C2 to C18, benzoic, biphenylcarboxylic, and benzoic acid). Composition and molecular weight of the hyperbranched polyether scaffolds w…
The condensation of an aldehyde with a dipyrromethane bearing a sterically unhindered aryl substituent at the 5-position typically results in low yield and a mixture of porphyrin products derived from acidolytic scrambling. We have developed a concise nonscrambling synthesis of such trans-porphyrins that takes advanta…
13 C NMR shift and spin−lattice relaxation measurements have been used to investigate 13 CO (ex MeOH) on fuel cell grade Pt electrodes (having average particle diameters of 2, 2.5, and 8.8 nm) in an electrochemical environment from 80 to 293 K at 8.47 and 14.1 T. The temperature dependence of the 13 C spin−lattice rel…
Static electrical and magnetic properties of single crystal BaVS_3 were measured over the structural (T_S=240K), metal-insulator (T_MI=69K), and suspected orbital ordering (T_X=30K) transitions. The resistivity is almost isotropic both in the metallic and insulating states. An anomaly in the magnetic anisotropy at T_X…
The phase diagram of BaVS3 is studied under pressure using resistivity measurements. The temperature of the metal to nonmagnetic Mott insulator transition decreases under pressure, and vanishes at the quantum critical point p_cr=20kbar. We find two kinds of anomalous conducting states. The high-pressure metallic phase…
We calculate the first hyperpolarizability (β) of several thiazole and thiophene analogues of donor−acceptor stilbene compounds using the ZINDO (sum-over-states) formalism. Because of the inherent dipolar nature of thiazole, in which C2 is electron-poor and C5 is electron-rich, the relative orientation of the thiazole…
Single-file diffusion, prevalent in many processes, refers to the restricted motion of interacting particles in narrow micropores with the mutual passage excluded. A single-filing system was developed by confining colloidal spheres in one-dimensional circular channels of micrometer scale. Optical video microscopy stud…
Confocal microscopy was used to directly observe three-dimensional dynamics of particles in colloidal supercooled fluids and colloidal glasses. The fastest particles moved cooperatively; connected clusters of these mobile particles could be identified; and the cluster size distribution, structure, and dynamics were in…
The tensile strengths of individual multiwalled carbon nanotubes (MWCNTs) were measured with a "nanostressing stage" located within a scanning electron microscope. The tensile-loading experiment was prepared and observed entirely within the microscope and was recorded on video. The MWCNTs broke in the outermost layer…
Chemical sensors based on individual single-walled carbon nanotubes (SWNTs) are demonstrated. Upon exposure to gaseous molecules such as NO(2) or NH(3), the electrical resistance of a semiconducting SWNT is found to dramatically increase or decrease. This serves as the basis for nanotube molecular sensors. The nanotub…