Materials Literature
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Abstract 2,3‐Diketocarboxymethylcellulose was prepared by the oxidation of carboxymethylcellulose (CMC) with potassium permanganate in alkaline solutions (pH ≥ 12) with a yield of 98.1%. IR spectroscopy and microanalysis have elucidated the chemical structure of the synthesized macromolecule (CMCK). A tentative reacti…
Time-of-flight quasielastic neutron scattering experiments have been performed on solid solutions of Na2SO4 and Na3PO4 in order to examine the reorientational anion motion in the picosecond range. The obtained data were analysed on the basis of the Q-dependent quasielastic intensity. Comparing the predictions of diffe…
Abstract Poly[( R,S )‐3‐hydroxybutyrate] oligomers containing dihyroxyl (PHB‐diol), dicarboxylic acid (PHB‐diacid) and hydroxyl‐carboxylic acid (a‐PHB) end functionalities were obtained by the anionic polymerization of β‐butyrolacton (β‐BL). Ring opening anionic polymerization of β‐BL was initiated by a complex of 18‐…
Abstract Raman and surface‐enhanced Raman scattering (SERS) spectra of 3‐phenylpropionic acid on silver colloids at several concentrations and pH values were recorded. The analysis of the spectra indicated that 3‐phenylpropionic acid links to the metal through its carboxylate group, keeping the aromatic ring almost pe…
The effect on the nematic to smectic-A transition in octylcyanobiphenyl (8CB) due to dispersions of hydrogen-bonded silica (aerosil) particles is characterized with high-resolution x-ray scattering. The particles form weak gels in 8CB creating a quenched disorder that replaces the transition with the growth of short-r…
Abstract The adsorption behavior of 4,4′‐dicyanobiphenyl (DCBP) on Ag and Au nanoparticle surfaces was studied by surface‐enhanced Raman scattering (SERS). The absence of the ring CH band denoted a flat orientation of the biphenyl ring on Ag and Au. The red shift of the ν 8a band indicated a direct ring π‐orbital inte…
In this paper we report modifications of the surface enhanced Raman scattering (SERS) spectra with film thickness of carbon single-walled nanotubes (SWNTs). The decrease of film thickness reveals an increased degree of disorder, which is interpreted in terms of degradation of the single-walled nanotubes and the format…
Abstract To facilitate the characterization of polymer networks, a comparison was made between branching theory and Monte Carlo simulations using an amine‐cured epoxy as an example for step‐growth polymer networks. The primary objective was the validation of the simulation results with the existing statistical theorie…
Abstract The mechanical properties of flyash‐filled natural rubber were investigated and compared with those filled with calcium carbonate. A number of composites with varying percentage of the fillers were prepared using a two‐roll mill and molded on compression molding press. Specimens were subjected to mechanical t…
The average magnetic susceptibilities for trivalent rare earth (R3+) ions in polycrystalline tetragonal rare earth oxybromides (ROBr, R = Ce–Nd, Sm, Eu, and Tb–Yb) were measured between 2 and 298 K. The susceptibilities of all ROBr follow the paramagnetic Curie–Weiss behaviour down to low temperatures except for SmOBr…
Abstract In vitro degradation of poly( L ‐lactic acid) (PLLA) fibers was studied by incubating the fibers in phosphate buffered saline (pH 7.4) at 37°C for 35–45 weeks. Three kinds of PLLA fibers with different diameters and different initial viscosity‐average molecular weights were tested. The viscosity‐average molec…
Synthetic hydrocerussite [trilead dihydroxide dicarbonate, Pb(3)(CO(3))(2)(OH)(2)] can be easily obtained, as a white powder, by the action of carbon dioxide and water on either lead or litharge at pH 4-5. This compound is also found in lead corrosion technological products as a fine-grained phase. Ab initio crystal s…
Magnetic nanoparticles (Ni, CoNiFe) with diameters ranging from 30 to 200 nm were synthesized by electrodeposition using carbon nanowalls as templates. A series of experiments have been carried out to study the formation mechanism of nanoparticles. It was found that the formation of nanoparticles instead of continuous…
The crystallization of polymeric and metallic materials normally occurs under conditions far from equilibrium, leading to patterns that grow as propagating waves into the surrounding unstable fluid medium. The Mullins-Sekerka instability causes these wave fronts to break up into dendritic arms, and we anticipate that…
Hybrid systems consisting of the conducting layers of organic donor molecules and the magnetic layers of inorganic anions have been focused on as possible bifunctional materials, whose conducting properties can be tuned by controlling the magnetic state of the anion layers on an application of magnetic field. Here we…
We report on a neutron spin echo investigation of the intermediate scale dynamics of polyisobutylene studying both the self-motion and the collective motion. The momentum transfer (Q) dependences of the self-correlation times are found to follow a Q(-2/beta) law in agreement with the picture of Gaussian dynamics. In t…
A quantitative analysis is presented for the site-selective Fe K-edge absorption spectra of Prussian Blue: Fe(4)[Fe(CN)(6)](3) x xH(2)O (x = 14-16). The site-selective spectra were recorded using high-resolution fluorescence detection of the K beta emission from a polycrystalline sample. The K beta fluorescence lines…
Poly(amidoamine) PAMAM dendrimers of various generations (generation 2 to generation 6) with different surfaces (amine, Tris, and pivalate) were used as organic templates to form complexes and nanocomposites of silver. Starting from silver salts and PAMAM dendrimers, first a silver−dendrimer complex and then a nanocom…
Extensive molecular dynamics simulation studies of particles interacting via a short-ranged attractive square-well potential are reported. The calculated loci of constant diffusion coefficient D in the temperature-packing fraction plane show a reentrant behavior, i.e., an increase of diffusivity on cooling, confirming…
All four isotropic contributions to the NMR fluorine−fluorine coupling constants (Fermi contact, FC, spin-dipolar, SD, paramagnetic spin−orbit, PSO, and diamagnetic spin−orbit, DSO) have been calculated for 2,6-difluoropyridine, 2,4,6-trifluoropyridine, perfluoropyridine, and 2-Br-3,4,5,6,7,8-hexafluoroquinoline by me…