Materials Literature
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Abstract Biodegradable poly( L ‐lactic acid) (PLLA) fibers were processed by a two‐step melt‐spinning method (melt extrusion and hot draw) from PLLA with three different viscosity‐average molecular weights (494,600, 304,700, and 262,800). Before spinning, the polymer flakes were first milled into powders and dried und…
Abstract Halogen‐free flame‐retarded polyethylene materials have been prepared by using magnesium hydroxide (MH) as a flame retardant combined with red phosphorous (RP) and expandable graphite (EG) as synergists. The effects of these additives on the combustion behavior of the filled linear low density polyethylene (L…
Abstract A dissolution/reprecipitation route was followed for the recycling of poly(ethylene terephthalate) (PET). Model experiments on virgin material, either in the form of pellets or blow‐molded bottles, are presented. The process proposed comprises dissolution of the plastic in an appropriate solvent, reprecipitat…
The non-equilibrium dynamics of the model 3d-Ising spin glass - Fe$_{0.55}$Mn$_{0.45}$TiO$_3$ - has been investigated from the temperature and time dependence of the zero field cooled magnetization recorded under certain thermal protocols. The results manifest chaos, rejuvenation and memory features of the equilibrati…
Abstract In this study, rigid thermoset polymers were prepared from radical copolymerization of the soybean oil monoglyceride maleates with styrene. In the first part of the study, soybean oil monoglycerides (SOMGs) were obtained from the reaction of soybean oil with glycerol at 220–240°C with an optimization of the r…
We present results of a simulation study of a fluid of hard spherocylinders with a length-to-diameter ratio of 15 in contact with a planar hard wall and confined by two parallel hard walls. A Monte Carlo method is developed for simulating fluids in contact with a single wall. Using this method, we find a transition fr…
Ultrafine ${\mathrm{MnFe}}_{2}{\mathrm{O}}_{4}$ powders have been synthesized via the displacement reaction $2{\mathrm{FeCl}}_{3}+4\mathrm{MnO}\ensuremath{\rightarrow}{\mathrm{MnFe}}_{2}{\mathrm{O}}_{4}+3{\mathrm{MnCl}}_{2}$ activated by high-energy ball milling. Single-phase ${\mathrm{MnFe}}_{2}{\mathrm{O}}_{4}$ powd…
We show that the argument of Alexander and McTague, that the bcc crystalline structure is favored in those crystallization processes where the first order character is not too pronounced, is not correct. We find that any solution that satisfies the Alexander-McTague condition is not stable. We investigate the implicat…
We report on syntheses and electron transport properties of polycrystalline samples of diborides (AB2) with different transition metals atoms (A=Zr,Nb,Ta). The temperature dependence of resistivity, ρ(T), and ac susceptibility of these samples reveal superconducting transition of ZrB2 with Tc=5.5 K, while NbB2 and TaB…
Atomistic computations of the Peierls stress in fcc metals are relatively scarce. By way of contrast, there are many more atomistic computations for bcc metals, as well as mixed discrete-continuum computations of the Peierls-Nabarro type for fcc metals. One of the reasons for this is the low Peierls stresses in fcc me…
The Raman spectra of ${\mathrm{PbZr}}_{1\ensuremath{-}x}{\mathrm{Ti}}_{x}{\mathrm{O}}_{3}$ ceramics with titanium concentration varying between $x=0.40$ and 0.60 were measured at 7 K. By observing the concentration-frequency dependence of the vibrational modes, we identified the boundaries among the rhombohedral, mono…
Superconductivity and structural properties of Mg1-xAlxB2 materials have been systematically investigated. Evident modifications in both superconductivity and microstructure are identified to originate from the Al ordering along the c-axis direction. The resultant superstructure phase has an optimal composition of MgA…
The growth of multilayers made from a combination of a weak polyacid and a strongly dissociated polycation is studied as a function of salt concentration and molecular weight. Film thickness reaches a maximum at around 0.3 M salt and then decreases quickly. Preformed multilayers are shown to decompose rapidly and, for…
A revised crystal structure for mercerized cellulose based on high-resolution synchrotron X-ray data collected from ramie fibers is reported (space group P2(1), a = 8.10(3) A, b = 9.03(3) A, c = 10.31(5) A, gamma = 117.10(5) degrees; 751 reflections in 304 composite spots; theta < 21.11 degrees; lambda = 0.7208 A; LAL…
Einem Karussell ähnelt die Struktur der Titelverbindung [1⋅2 Py] (siehe Bild), der ersten Verbindung eines neuen Strukturtyps, die durch hochselektive Kondensationsreaktionen aus dem ebenfalls neuartigen [Fe(C5H4GaMe2)2] hergestellt wurde. Als Zwischenprodukt bildet sich das erste galliumverbrückte [m.m]Ferrocenophan…
Sensitised excitation of the DMN[3]DCME donor[bridge]acceptor system allows population of a triplet CT state with a microsecond lifetime in polar solvents. This is more than five orders of magnitude longer than the lifetime of the corresponding singlet CT state which is populated exclusively upon direct excitation. Th…
Das Wildtyp-Protein denaturiert unter Bedingungen, bei denen die Sekundär- und Tertiärstruktur der fluorierten Variante stabil bleiben. Dies ist auf den Einbau von 5′,5′,5′-Trifluorleucin 2 anstelle von Leucin 1 in ein Leucin-Reißverschluss-Protein bei der Biosynthese von E. coli zurückzuführen. Fluorierung des hydrop…
Without requiring chelation by sensitizers, a method to detect lanthanides by multiphoton excitation is reported. This suggests the use of lanthanides as calcium analogues in multiphoton microscopy. The spectrum shows the normalized two-photon excitation emission spectra (λex = 796 nm) of Eu(3+) with a resolution of a…
Abstract The formation and physicochemical properties of polymer electrolytes strongly depend on the lattice energy of metal salts. An indirect but efficient way to estimate the lattice energy through the relationship between the heterolytic bond dissociation and lattice energies is proposed in this work. The heteroly…
A multitechnique approach has allowed the first experimental determination of single-ion anisotropies in a large iron(III)-oxo cluster, namely [NaFe6(OCH3)12(pmdbm)6ClO4 (1) in which Hpmdbm = 1,3-bis(4-methoxyphenyl)-1,3-propanedione. High-frequency EPR (HF-EPR). bulk susceptibility measurements, and high-field cantil…