Materials Literature
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Abstract Constant pressure constant temperature molecular dynamics method is employed to investigate the atomistic scale dynamics of a model Bisphenol A polycarbonate in the vicinity of its glass transition temperature. First, the glass transition temperature and the thermal expansion coefficients of the polymer are p…
Abstract Whether crystalline or amorphous sp 3 ‐bonded carbon nitrides containing substantial amounts of nitrogen can be synthesized remains an open question. Various deposition techniques and high pressure syntheses to 40 GPa have not been successful thus far. The use of appropriately designed molecular or solid‐stat…
Diatom seasonal succession and interannual variability were studied using laminated sediments from Saanich Inlet, British Columbia, for the years 1900–1991. Frozen sediment cores allowed fine-scale sampling of laminae for each year. Thus, three ‘seasons’ for each year were identified based on species composition. Thal…
Inorganic–organic hybrids containing various inorganic components have been successfully synthesized from silanol-terminated poly(dimethylsiloxane) (PDMS) and three different inorganic sources, Al(OBu s ) 3 , Ti(OEt) 4 and Ta(OEt) 5 , by using a sol–gel process. Inorganic components as well as the process conditions w…
Porous clay heterostructures formed by surfactant assembly of open framework silica in the galleries of a smectite clay represent a new family of solid acid catalysts, as evidenced by the selective dehydration of 2-methylbut-3-yn-2-ol to 2-methylbut-3-yn-1-ene.
A bioresorbable aliphatic polyester was synthesized by bulk copolymerization of a 1/1 M/M L,L-lactide/epsilon-caprolactone mixture using zinc metal as initiator. The actual composition of the copolymer was found to be 1.5/1 as deduced from 1H NMR spectra obtained in DMSO-d6 solutions where higher resolution was obtain…
All articles of this category Transition metal phthalocyanines 3 a-g, 4e, f and 5 e, g substituted with sixteen alkoxy groups and various chain lengths were synthesized from the corresponding tetraalkoxyphthalodinitriles and characterized by spectroscopic methods. In the UV/vis spectra of the hexadecaalkoxy-substitute…
The pH-dependent reaction of [Ru(η 6 -C 6 H 6 )(D 2 O) 3 ] 2+ with adenosine and guanosine 5′-mono-, -di- and -tri-phosphates has been studied by 1 H and 31 P-{ 1 H} NMR spectroscopy. Diastereomeric µ-1κN 1 :2κ 2 N 6 , N 7 co-ordinated cyclic trimers of the type [{Ru(5′-AMP)(η 6 -C 6 H 6 ) } 3 ] predominate for adenos…
Potentiodynamic techniques were used to compare the effects of tolytriazole (TTAH) and benzotriazole (BTAH) corrosion inhibitors on anodic polarization behavior of copper in 1 M sodium chloride (NaCl). Variations in experimental procedure included the injection of inhibitor before commencing the potential scan, inject…
A convenient immobilisation of triazacyclononane ligands on a glycidylated surface leads to a new group of active, heterogeneous manganese epoxidation catalysts.
We report the preparation of transparent gels from concentrated sols of CdS nanocrystals. The principles of our method can be applied to other systems, enlarging the domain of the inorganic sol–gel process which so far has been restricted mainly to oxides.
The title compound (1) crystallites in the space group Pmn2(1) with a = \n13.110 (3), b = 5.813(1) and c = 6.482(1) Angstrom. Its crystal \nstructure was redetermined from three-dimensional single-crystal data \nto a final R-value of 0.0221. The Cd2+ ion is tetrahedrally coordinated \nto two sulfur ato…
Abstract: All lenses, whether for light or for electrons, have aberrations that limit their performance. In light optics the invention of the achromat over 200 years ago solved the problem of correcting spherical and chromatic aberrations; however, correcting aberrations of electron lenses remains a challenge. Spheric…
Polyaniline (PAN) and polypyrrole (PPY) were analyzed by X-ray photoelectron spectroscopy (XPS) and bulk analytical techniques. A systematic comparison of the results was carried out to determine the effects of anion size, synthesis methods, and the nature of the polymer (powder or film) on the variation between the s…
The tubular design of solid oxide fuel cells (SOFCs) and the materials used therein have been validated by successful, continuous electrical testing over 69,000 h of early technology cells built on a calcia-stabilized zirconia porous support tube (PST). In the latest technology cells, the PST has been eliminated and r…
The construction of nanometric, dendritic macromolecules by bis(2,2′:6′,2″-terpyridine)ruthenium(ii) connectivity is investigated. The assembly methodology, which incorporates both the control of metal complexation sites and degree of flexibility within the linkages, has been demonstrated.
Experimental observation and study of light induced relief gratings in chalcogenide glasses is presented. Holographic exposure of the glass film by near bandgap light leads to a real-time periodic thickness self-expansion without further processing. The dynamics of surface modulation is not monotone with respect to th…
2-(Dimethylamino)ethyl methacrylate (DMAEMA) was block copolymerised in turn with three other tertiary amine methacrylate comonomers using group transfer polymerisation; the DMAEMA residues of each of these diblock copolymers wereselectively betainised using propane-1,3-sultone under mild conditions to yield a series…
New intercalated compounds have been prepared by incorporating carboxymethyl-β-cyclodextrin (CMCD) into magnesium–aluminum layered double hydroxide (Mg/Al LDH). The sorptive uptake of CMCD(3) and CMCD(14), with a degree of carboxymethyl substitution of 3 and 14, respectively, by Mg/Al LDH was examined at 65 °C, and th…
Metal-free phthalocyanine derivatives 2 and 14 bearing eight and four peripheral tetrathiafulvalene (TTF) units, respectively, have been synthesised, and their solution electrochemistry and optical spectroscopy have been studied. The compounds display redox properties arising from the TTF and from the phthalocyanine g…