Materials Literature
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Thermolysis of N-trialkyl borazines at 500 degrees C produces homogeneous, amorphous boron carbonitride phases, whose compositions are dependent upon the borazine substituent, and whose structures are similar to that of icosahedral boron carbide, B4C.
We report on the atomic force microscope observation of an electrostatic force between glass surfaces immersed in cyanobiphenil liquid crystals. The measured force is repulsive and decays exponentially with increasing surface separation. A mean field description of the electrostatic interaction in liquids has been use…
Bimetallic tris-oxalato-salts (n-CnH2n+1)PPh3MIIFeIII(C2O4)3 (n = 3–7, MII = Mn, Fe) were prepared and the structures investigated by powder X-ray diffraction in order to study the evolution of the structure and magnetic properties as a function of alkyl chain length. The compounds all have the same two-dimensional ho…
Abstract The syntheses of amphiphilic AB‐type diblock copolymers composed of hydrophobic polylactide segment and hydrophilic polydepsipeptide segment with amino or carboxyl groups were performed. The protected cyclodepsipeptides cyclo[Glc‐Lys(Z)] and cyclo[Glc‐Asp(OBzl)] (where Glc is glycolic acid, Lys is lysine, Asp…
Kanonerovite, MnNa 3 P 3 O 1 0 .12H 2 O [a = 14.71(1) A, b = 9.33(1) A, c = 15.13(2)A, β = 89.8(1)°, V = 2075(3) A 3 , P2 1 /n, Z = 4], is the first described triphosphate mineral. It has been found in the Kazennitsa pegmatite vein, the Alabashka pegmatite field, Middle Urals, Russia. Associated minerals are quartz, a…
Abstract The thermal decomposition mechanism of maleated poly(3‐hydroxybutyrate) (PHB) was investigated by FTIR and 1 H NMR. The results of experiments showed that the random chain scission of maleated PHB obeyed the six‐membered ring ester decomposition process. The thermal decomposition behavior of PHB and maleated…
Multiplet splittings for several excited configurations of [Co(II)W(12)O(40)](6-) were calculated using DFT methods. In agreement with the experimental interpretation of the spectrum the calculations found that the first strong band corresponds to Co d-d transitions, but it is worth noting that superposed to these tra…
Abstract Poly(L‐lactide)‐poly(ethylene glycol) multiblock copolymers with predetermined block lengths were synthesized by polycondensation of PLA diols and PEG diacids. The reaction was carried out under mild conditions, using dicyclohexylcarbodiimide as the coupling agent and dimethylaminopyridine as the catalyst. Th…
Atactic poly( R, S -3-hydroxybutyrate) (a-PHB) was synthesized by anionic polymerization of β-butyrolactone with potassium methoxide as an initiator. This completely amorphous polyester is capable of forming a crystalline inclusion complex (IC) with γ-cyclodextrin (γ-CD) adopting a channel structure. There is no evide…
We propose that a chain of five-membered rings (polyaminotriazole) should be ferromagnetic with an appropriate doping that is envisaged to be feasible with a field-effect transistor structure. The ferromagnetism is confirmed by a spin density functional calculation, which also shows that ferromagnetism survives the Pe…
Inelastic x-ray scattering data have been collected for liquid sodium at T=390 K, i.e., slightly above the melting point. Owing to the very high instrumental resolution, pushed up to 1.5 meV, it has been possible to determine accurately the dynamic structure factor S(Q,omega) in a wide wave-vector range, 1.5-15 nm(-1)…
Open single-walled carbon nanotubes (SWNTs) are attractive as potential storage media for hydrogen gas. The present paper investigates the micropore structure of HiPco SWNTs samples, as studied by nitrogen and argon adsorption technique at low pressures. The proportion of open SWNT is estimated with the Horvath−Kawazo…
HiPco single-walled carbon nanotube (HPNT) containing Fe was purified by one-step purification with HCl-washing (D-method) and two-step purification with HCl-washing after air oxidation (GD-method). The N 2 adsorption isotherm of HPNT at 77 K is of type II and it changes to type IV after purification. Purification by…
Abstract A two‐part study utilizing polyoxymethylene (POM) was undertaken to investigate a three‐stage process (melt‐extrusion/annealing/uniaxial‐stretching) utilized to produce microporous films. In this report, the thermal annealing (second stage) and subsequent uniaxial‐stretching (third stage) results of selected…
The structure and bonding in [M(6)O(19)](n-) isopolyanions of Nb, Ta, Mo, and W have been investigated using density-functional methods. The computational-experimental agreement is good for the geometrical parameters of Mo and W species but less satisfactory for Nb and Ta clusters. The electronic structure of the anio…
To meet the goals of sustainability and to enable industrial ecology, green chemistry and engineering needs to be studied from a life-cycle perspective. When designed correctly, green chemistry and engineering can affect multiple stages of the life cycle of a product or process. Successful implementations of green che…
We describe a novel method to prepare monodisperse Pickering emulsions. We start with classical surfactant-stabilized oil-in-water emulsions, which are sheared and size fractionated to attain monodispersity. Then, the surfactant is removed by a dialysis method and simultaneously replaced by solid particles. We obtain…
The corrosion of mild steel in a seawater medium containing extracellular polymeric substances (EPS) produced by sulfate-reducing bacteria (SRB) was studied by electrochemical experiments and atomic force microscopy (AFM). Under anaerobic conditions, the corrosion of mild steel increased up to 5-fold in the presence o…
We have performed first-principles calculations on field emission (FE) from graphitic ribbons within the time-dependent density-functional theory. An important finding is that dangling bond states localized at clean edges are major contributors to FE current. H termination makes the FE current small due to the disappe…
Achiral banana-shaped molecules with dodecyloxy tail groups, P-12-O-PIMB, N-12-O-PIMB, and S-12-O-PIMB, have exhibited unusual smectic phases which possess chiral and helical structures. In this work, we mixed these banana-shaped molecules with the chiral molecule forming a chiral nematic liquid crystal and found an e…