Materials Literature
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Poly(L-lactide) (PLLA) and poly(epsilon-caprolactone) (PCL) ultrafine fibers were prepared by electrospinning. The influence of cationic and anionic surfactants on their enzymatic degradation behavior was investigated by measuring weight loss, molecular weight, crystallinity, and melting temperature of the fibers as a…
Abstract A linear empirical correlation was established between Raman stretching wavenumbers of phosphorus–oxygen bonds and their bond lengths in inorganic crystalline phosphates. Although established on samples of inorganic crystalline phosphates, the correlation can be applied to glassy and amorphous phosphate mater…
Transient homogeneous nucleation is studied in the limit of large critical sizes. Starting from pure monomers, three eras of transient nucleation are characterized in the classic Becker-Döring kinetic equations with two different models of discrete diffusivity: the classic Turnbull-Fisher formula and an expression des…
The nature of orbital order-disorder transition has been studied in the La(1-x)Nd(x)MnO(3) (x = 0.0-1.0) series which covers the entire range between two end points - LaMnO(3) and NdMnO(3) - as well as in La(0.85)Nd(0.1)Sr(0.05)MnO(3) and La(0.8)Nd(0.1)Sr(0.1)MnO(3). It has been observed that the first-order nature of…
Field emission (FE) and the electronic-states origin of graphitic nanostructures were investigated by first-principles calculations based on time-dependent density-functional theory. We find that the FE current from graphitic ribbons changes remarkably depending on the hydrogen termination and the direction of the app…
We present a general method for the design of 2-dimensional nonlinear photonic quasicrystals that can be utilized for the simultaneous phase-matching of arbitrary optical frequency-conversion processes. The proposed scheme--based on the generalized dual-grid method that is used for constructing tiling models of quasic…
We report an interesting reentrant metallic resistivity pattern beyond a characteristic temperature T* which is higher than other such characteristic transition temperatures like T(c)(Curie point), T(N) (Neel point), T(CO) (charge order onset point) or T(OO) (orbital order onset point) in a range of rare-erath perovsk…
A mixed oxide-electron conducting ceramic, La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 - α (LSCF), hollow-fiber membrane was prepared by a combined phase-inversion/sintering technique. The hollow-fiber membrane precursor was first spun from a starting solution containing 66.33 wt % LSCF powder, 6.63 wt % PESf binder, 0.5 wt % PVP…
The flexural properties of a particle adsorption monolayer are investigated theoretically. If the particles are not densely packed, the interfacial bending moment and the spontaneous curvature (due to the particles) are equal to zero. The situation changes if the particles are closely packed. Then the particle adsorpt…
The self-assembly of nanoparticles at fluid interfaces, driven by the reduction in interfacial energy, was investigated. With spherical, tri-n-octyl-phosphine-oxide covered cadmium selenide (CdSe) nanoparticles (1-8 nm), thermal fluctuations compete with the interfacial segregation giving rise to a size-dependent self…
Through three case studies, plane wave pseudopotential density functional theory calculations are performed to investigate the mechanism of second harmonic generation (SHG) of the nonlinear optical materials. We want to know how SHG coefficients are affected by: (1) anion substitution in $\mathrm{AgGa}{({\mathrm{S}}_{…
Porphyrins and fullerenes are spontaneously attracted to each other. This new supramolecular recognition element can be used to construct discrete host-guest complexes, as well as ordered arrays of interleaved porphyrins and fullerenes. The fullerene-porphyrin interaction underlies successful chromatographic separatio…
A study of step edges in graphite with different atomic structures combining Raman spectroscopy and scanning probe microscopy is presented. The orientation of the carbon hexagons with respect to the edge axis, in the so-called armchair or zigzag arrangements, is distinguished spectroscopically by the intensity of a di…
In this article we describe the synthesis, characterization, and applications of dendrimer-encapsulated nanoparticles (DENs). These materials are synthesized by a template approach in which metal ions are extracted into the interior of dendrimers and then subsequently chemically reduced to yield nearly size-monodisper…
The electrical characteristics of single CoPt3 nanocrystal microwires formed by magnetic field-directed growth from colloidal solutions are presented. The wires comprise disordered assemblies of discrete nanocrystals, separated from each other by protective organic ligand shells. Electrical data indicate that the acti…
The dynamics of two molecular glass formers are monitored at microsecond scales via muon spin relaxation. Measurements in transverse magnetic fields display unambiguous signatures of critical behavior at temperatures somewhat above those signaling the thermodynamic glass transition, namely at the onset of stochastic m…
Abstract A new naphthalene‐ring‐containing bis(ester–amine), 1,5‐bis(3‐aminobenzoyloxy)naphthalene, was prepared from the condensation of 1,5‐dihydroxynaphthalene with 3‐nitrobenzoyl chloride followed by catalytic hydrogenation. A series of novel naphthalene‐containing poly(ester–amide)s was synthesized by direct phos…
Abstract From chloromethylated polyimide, a useful starting material for modification of aromatic polyimides, a thermocurable transparent polyimide having acrylate side groups was prepared. In the presence of 1,8‐diazabicyclo[5,4,0]undec‐7‐ene, chloromethylated polyimide was esterified with acrylic acid to synthesize…
Abstract Some hydrogen‐bonding‐interactions‐mediated poly(ε‐caprolactone) (PCL)/silica (SiO 2 ) polymeric‐inorganic hybrids were prepared by the sol–gel process. The non‐isothermal crystallization kinetics of PCL in the hybrids was investigated by means of differential scanning calorimetry. The results show that the J…
Abstract Density functional theory calculations are used to determine the kinetics and reactivity indices of the first propagation steps of the polyethylene and poly(vinyl chloride) polymerization. Transition state theory is applied to evaluate the rate coefficient from the microscopically determined energies and part…