Materials Literature
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We investigate and discuss how hydrogen behaves at the edges of a graphite sheet, in particular the armchair edge. Our density functional theory-based calculations results show that, in contrast to the zigzag edge [cf., e-J. Surf. Sci. Nanotech. 2 (2004) 77], regardless of orientation, there is an activation barrier h…
Resistance of vacuum deposited ${\rm Sb_2Te_3}$ films of thickness between 100-500nm has been measured in vacuum. It is found that the resistance of the polycrystalline films strongly depends on the grain size and inter-granular voids. The charge carrier are shown to cross this high resistivity inter- granular void by…
Classical continuum elastic calculations show that the acoustic vibrational modes of an embedded nanoparticle can be lightly damped even when the longitudinal plane wave acoustic impedances $Z_o=ρv_L$ of the nanoparticle and the matrix are the same. It is not necessary for the matrix to be less dense or softer than th…
Porous silica exhibiting a hierarchically ordered trimodal pore system with a well-defined reverse opal microstructure and bimodal mesoporosity in the walls has been prepared by using polystyrene latex spheres, a novel block copolymer and an ionic liquid surfactant as templates. The resulting materials exhibit hierarc…
Nanoparticle and nanocluster precursors may play a major role in biomineralization. The small differences in enthalpy and free energy among metastable nanoscale phases offer controlled thermodynamic and mechanistic pathways. Clusters and nanoparticles offer concentration and controlled transport of reactants. Control…
Recently, artificially constructed metamaterials have become of considerable interest, because these materials can exhibit electromagnetic characteristics unlike those of any conventional materials. Artificial magnetism and negative refractive index are two specific types of behavior that have been demonstrated over t…
The E′δ-defect-enhanced photoconductivity of a metal–semiconductor–metal photodetector (MSM-PD) made on Si-implanted borosilicate glass (BSO:Si+) substrate is reported. The dark current of as-implanted BSO:Si+ MSM-PD is only 0.1nA at bias of 70V. The photocurrent of as-implanted BSO:Si+ MSM-PD illuminated at 488nm is…
Abstract Poly(ethylene glycol) (PEG) has been widely used in studies of polymer–clay nanocomposites because it readily intercalates in smectite clays. Nanocomposites were formed from PEG with molecular weights ( M w ) ranging from 300 to 20,000, as evidenced by expansion of the basal planar spacing of the clay ( d 001…
Dideoxysugars, which display biological activities ranging from mediating cell-cell interactions to serving as components in some antibiotics, are synthesized in various organisms via complex biochemical pathways that begin with the attachment of alpha-D-glucose 1-phosphate to either CTP or dTTP. Here we describe the…
A power second-harmonic generation (SHG) study has been carried out on (K2O)15(Nb2O5)15(TeO2)70 glass ceramic, which consists of centrosymmetric crystals embedded in a centrosymmetric glass matrix. The effective second-order nonlinear optical coefficient, χ(2), of this material at 532nm is found to be 1.3pm∕V or appro…
Novel lead-bismuthate glasses with low OH concentration have been obtained in the Bi 2 O 3 –PbO–SrO system. The role of the different components in the glass formation has been explored from the density, refractive index measurements, indicating that the physical properties are mainly affected by Bi 2 O 3 and PbO cont…
A novel design of anticancer drug delivery system, based on an electrostatic binding of negatively charged liposomes and cationic metalloporphyrins under physiological conditions, is reported. A lack of cytotoxicity of the iron(III) porphyrin-loaded liposomes and an efficient generation of a toxic hydroxyl radical (OH…
The ultrafast optical emission of nanosized (∼5nm) crystallites has been detected under the picosecond (ps) laser excitation of 300nm through ultrafast fluorescence spectroscopy. This optical emission, photoluminescence (PL), induced at a laser wavelength of 300nm confines blue light. The ultrafast PL spectrum deconvo…
Abstract Sorption and diffusion of supercritical carbon dioxide (SCCO 2 ) into polysulfone (PSF) from 313 K and 20 MPa to 333 K and 40 MPa were investigated in this study. A simple gravimetric method was used to measure the mass gain of SCCO 2 in PSF, and the Fick's diffusion model was applied to describe the desorpti…
A pentacene nanocrystal transistor with carbon nanotube electrodes as a nanosize source and drain was realized. In the device fabrication, the evaporated pentacene selectively grew around the nanotube electrodes. This may be caused by the common nanounit combination of the carbon six-membered ring contained in the pen…
Abstract The modification of the polarity of isotactic polypropylene (iPP) through blending with oxidized paraffin wax (Fischer–Tropsch synthesis) was investigated. The oxidized paraffin wax significantly increased the polar component of the total surface free energy of polypropylene. Modified iPP also showed signific…
Abstract Solid structure formation in the drying step for wet spinning of poly(1‐oxotrimethylene) using as a solvent an aqueous solution of complex metal salts of calcium chloride/zinc chloride was studied. Because the degree of structural densification and the crystal structure both differ depending on the drying tem…
Abstract A novel reverse temperature profile for the injection molding of Biopol™ was studied. It was found that both the mechanical properties and the part quality of Biopol™ were improved with this new reverse temperature process. When injection molded, most conventional thermoplastic polymers are processed at 30 to…
Infrared dielectric function spectra and phonon modes of single-phase rocksalt-type MgxZn1−xO thin films with 0.67⩽x⩽1 prepared by pulsed-laser deposition on c-plane sapphire substrates were obtained from infrared spectroscopic ellipsometry (360cm−1 to 1500cm−1). A one-mode behavior is found. Phonon mode frequencies,…
Abstract Ethylene‐propylene diene rubber (EPDM) and isotactic polypropylene (iPP) blends have widest industrial applications that require a degree of flame retardancy. Halogen‐free intumescent technology based on phosphorous salt is a significantly advanced approach to make the polymer flame‐retardant. Both ammonium p…