Materials Literature
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We have developed epoxy-based, water-soluble azo polymers containing ionizable groups in the azobenzene functionality. We describe a novel approach of the noncentrosymmetric self-assembly of azobenzene chromophores in these polymers through a layer-by-layer deposition technique. The polymers in solution function as po…
Plasma polymer films were deposited from methyl methacrylate (MMA) vapor under various plasma conditions and XPS and FTIR used to study the changes to the compositions of the films as they were stored in air for longer than 1 year. The plasma power input per monomer mass unit (W/FM) markedly affected the composition o…
The authors have succeeded in fabricating low-loss tellurite-based Er3+-doped fibre for low noise 1.5 µm broadband EDFAs by developing high-purity TeO2 as a raw material. The background loss of the fibre is reduced to 0.054 dB/m at 1200 nm. A 20 dB signal bandwidth of 83 nm from 1528 to 1611 nm, and a low flat noise f…
We use light-scattering techniques to study the effects of methanol concentration on alkaline, cetyltrimethylammonium bromide (CTAB) water:methanol micellar solutions. We use X-ray diffraction, SEM, TEM, 29 Si NMR, and gas sorption measurements to study the structure, microstructure, and porosity of surfactant-templat…
Poly(L-lactic acid) filaments were prepared by high speed melt spinning at take-up velocities up to 5000 m/min. The crystallinity, birefringence, tensile strength, Young's modulus and yield strength all exhibit maxima at take-up velocities between 2000 and 3000 m/min. The boiling water shrinkage exhibits a minimum in…
Density functional calculations using the B3LYP, BP86, and FT97 functionals with an extended basis set are employed to investigate the mechanisms of H 2 oxidation by FeO + . Three mechanisms are considered, addition−elimination, “rebound”, and oxene-insertion. The oxene-insertion is characterized by high barriers and…
A high-pressure differential scanning calorimetric technique is described for studying polymer plasticization by compressed gases at pressures to 100 atm. The in situ measurements avoid problems due to gas desorption encountered with conventional DSCs, thus providing an accurate way to determine the change in glass tr…
The self-condensing vinyl polymerization of 4-(chloromethyl)styrene using metal-catalyzed living radical polymerization catalyzed by the complex CuCl/2,2′-bipyridyl has been attempted. Given the unequal reactivity of the two potential propagating species in this system, a variety of polymerization conditions were test…
Mesoporous titania and niobia molecular sieves were prepared by a ligand-assisted templating method. For comparison, titania samples were also prepared by simple hydrolysis and condensation of Ti alkoxide in the absence of templating agents. All materials were thoroughly characterized by UV−vis reflectance spectroscop…
Red and yellow soils from tropical regions are generally more mature than their subtropical counterparts. Most of these soils contain kaolin as the dominant clay mineral. Exchangeable aluminium (Al) generally balances permanent negative charges and occupies strongly acidic exchange sites of the soil clay. The objectiv…
The trinuclear compound [dmbReI(CO)3-bpy-RuIII(en)2NCFeIII(CN)5]Br was synthesized and characterized by UV/vis and IR spectroscopy. Irradiation of this complex in the presence of added phenothiazine leads to a mixed-valence Re(I)−Ru(III)−Fe(II) photoproduct and PTZ•+. Several possible photochemical processes are propo…
The mixed-valence molecule Sn II Sn IV (O i Pr) 6 is conveniently synthesized and is shown to exchange bridging and terminal alkoxides in solution in its Sn(μ-O i Pr) 3 Sn(O i Pr) 3 structure. Pb 3 SnO(O i Pr) 8 is synthesized and shown to undergo an intramolecular fluxional process in solution. Both molecules are suf…
Very sandy and sometimes seasonally inundated humus podzols of the Bassendean soil association in southwest Australia experience severe leaching of fertiliser P with consequent eutrophication of waterways. P sorption by these soils is mostly minimal and is primarily due to the podzol Bh horizon. The consequence of sea…
Scattering experiments were conducted on a critical, binary mixture of polyethylene (PE) and head-to-head polypropylene (PP), and a symmetric PE−PP diblock copolymer melt. The binary mixture exhibited a liquid−liquid phase transition at 143 °C, while the block copolymer exhibited an order−disorder transition at 149 °C…
Three compounds, BaDyCuTe 3, K 1.5 Dy 2 Cu 2.5 Te 5, and K 0.5 Ba 0.5 DyCu 1.5 Te 3, were synthesized from the reaction at 850 °C of the pure elements with fluxes such as BaCl 2 or a eutectic mixture of LiCl/KCl. The crystal structures of the three compounds were determined by the single-crystal X-ray method. The fina…
Plasma-induced low-density polyethylene (LDPE) radicals were studied in detail by electron spin resonance (ESR) by its comparison with ESR of high-density polyethylene (HDPE). The observed ESR spectra of plasma-irradiated LDPE are largely different in pattern from those of HDPE. The systematic computer simulation disc…
Electronic aspects of an iron porphyrin, 5,10,15,20-tetrakis(4-methoxyphenyl)-21 H,23 H -porphine iron(III) chloride (FeTMPPCl) molecularly dispersed on a high area carbon black (Black Pearls 2000, BP) and then heat-treated (or thermally activated) at 800 °C in a flowing inert atmosphere, were investigated in situ in…
We analyze the stability of a planar solid-solid interface at which a chemical reaction occurs. Examples include oxidation, nitridation, or silicide formation. Using a continuum model, including a general formula for the stress-dependence of the reaction rate, we show that stress effects can render a planar interface…
The validity of the adiabatic approach to spin-Peierls transitions is assessed. An alternative approach is developed which maps the initial magneto-elastic problem to an effective magnetic problem only. Thus the equivalence of magneto-elastic solitons and magnetic spinons is shown. No soft phonon is required for the t…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTPreparation of Cu Nanoclusters within Dendrimer TemplatesMingqi Zhao, Li Sun, and Richard M. CrooksView Author Information Department of Chemistry, P.O. Box 300012 Texas A&M University, College Station, Texas 77842-3012 Cite this: J. Am. Chem. Soc. 1998, 120, 19, 4877–…