Materials Literature
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Density functional supercell calculations were carried out by a mixed-basis pseudopotential method for the Σ3 (111) [1 0] symmetrical tilt grain boundary in strontium titanate, SrTiO 3 , as a prototype planar defect in an electro-ceramic material. A low grain boundary energy of 0.52 J m -2 was obtained. Minor structur…
Abstract Enzyme‐catalyzed transesterification of several cellulose solids in organic media have been investigated. Several protease enzymes were made soluble in organic media through ion‐paired enzyme–surfactant complexes. Subtilisin Carsberg was found to be catalytically active in the transesterification of cellulose…
Abstract The glass‐transition temperatures and melting behaviors of poly(ethylene terephthalate)/poly(ethylene 2,6‐naphthalate) (PET/PEN) blends were studied. Two blend systems were used for this work, with PET and PEN of different grades. It was found that T g increases almost linearly with blend composition. Both th…
The growth kinetics of a potassium sulfate crystal was investigated in the presence of traces of chromium(III) impurity (0.5 and 2 ppm) in a flow cell at different rates of change of supercooling (± 0.1 and ± 0.2 °C/min). Hysteresis in crystal growth rates with chromium(III) impurity was induced by decreasing and incr…
The concentration inside a crystalline layer was explored theoretically and experimentally for solid layer melt crystallizations. The distribution of the purity in the crystalline layer is modelled by a mass balance equation coupled with an energy balance equation. The mass balance equation is established with the com…
Abstract In this research, we used a new redox free radical initiation system consisting of potassium persulfate (K 2 S 2 O 8 ) and sodium hypophosphite (NaH 2 PO 2 ). In the presence of NaH 2 PO 2 , the thermal decomposition of K 2 S 2 O 8 is accelerated, and the temperature required for the formation of free radical…
Abstract To accomplish the stable internal plasticization of cellulose diacetate (CDA), maleic anhydride (MAH) and glycerol (Gly) were used as reactive plasticizers. The plasticization method used was based on a melt‐processing reaction of CDA with MAH and Gly. MAH and Gly (MG)‐plasticized CDA showed stiff and brittle…
Abstract This study investigates the electrical behavior, which is the positive temperature coefficient/negative temperature coefficient (PTC/NTC), and structure of polypropylene (PP)/ultrahigh molecular weight polyethylene (UHMWPE)/carbon black (CB) and PP/γ irradiated UHMWPE (XL‐UHMWPE)/CB blends. As‐received UHMWPE…
An x-ray diffraction and 31 P MAS NMR study of rare-earth phosphate glasses of composition, (R 2 O 3 ) x P 2 O 5 ) 1- x , where x = 0.175-0.263 and R = La-Er (except for Pm), is presented. The structures of these materials were investigated as a function of (a) rare-earth atomic number and (b) glass composition. The r…
The synthesis, characterization, and photophysical as well as electrochemical properties of the photochromic hybrid systems 11 – 16 and 18, which contain photoswitchable tetraethynylethene (TEE; 3,4-diethynylhex-3-ene-1,5-diyne) and dihydroazulene (DHA) moieties, are presented. The molecular photoswitches were synthes…
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…