Materials Literature
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Dithiolane-2,4-dione was polymerized either by heating in bulk to 140 °C or by reacting at 20 °C using pyridine and triethylamine as catalysts. Whereas the thermal polymerization almost exclusively yielded cyclic poly(thioglycolide), the samples prepared at 20 °C by means of tertiary amines contained cyclic and linear…
Rare vanadyl corrphycene and vanadyl 10-oxocorrole complexes were obtained via an oxidative macrocyclization process by the treatment of 6,6'-di-p-tolyl-2,2'-bidipyrrin with VO(acac)2 in a hot dioxygen atmosphere. The geometric and electronic structures of the new porpyhrinoids were determined and showed the dependenc…
Barium strontium titanate is a promising material for microwave‐phased array applications. In this study, highly dense and fine‐grained Ba 0.6 Sr 0.4 TiO 3 ceramics were prepared using the spark plasma sintering (SPS) technique. The structure and dielectric tunable properties of the samples were investigated. The “dis…
E to Z (trans-->cis) photoisomerization of azobenzene (Az) chromophores tagged to polystyrene (PS) in thin films was studied as functions of thickness, PS molecular weight, and temperature, using the change in absorption at 336 nm arising from the Az E isomer remaining upon ultraviolet light irradiation at 350+/-5 nm.…
The structural evolution and properties of poly(9,9-dihexylfluorene-alt-2,5-dialkoxybenzene) with different lengths of alkoxy side chains on phenylene have been systematically investigated by means of thermogravimetric analysis (TGA), X-ray diffraction (XRD), differential scanning calorimetry (DSC), polarizing light m…
Penetration experiments on glass found in the literature show that the target fails ahead of the projectile (the “failure wave” is faster than the penetration velocity). Thus, during penetration, the projectile is in contact with failed glass ahead; consequently, the properties of failed material are required for accu…
The objective of the present work is to investigate the friction and wear of self‐mated ZrO 2 ceramics in a cryogenic environment. Using a specially designed high‐speed cryo‐tribometer, fine‐grained yttria‐stabilized tetragonal ZrO 2 polycrystals (Y‐TZP) were worn at varying loads (5–15 N) with sliding speed of 1.1 m/…
A high‐aspect‐ratio platelet sodium niobate (NaNbO 3 ) was synthesized by a topochemical reaction. Plate‐like layered‐perovskite Bi 2.5 Na 3.5 Nb 5 O 18 (BNN5) as a precursor was first prepared, and then Bi 3+ in the precursor phase was replaced by Na + through topotactic conversion and perovskite NaNbO 3 formed at 95…
To study how architecture affects the liquid crystalline behavior of mesogen-jacketed liquid crystalline polymers (MJLCPs), a series of eight-arm star poly{2,5-bis[(4-methoxyphenyl)oxycarbonyl]styrene} (PMPCS) were synthesized and carefully characterized. The star polymers were successfully synthesized by atom transfe…
Abstract Novel unsymmetrical bolaamphiphile, bearing glucose- and triglycine-headgroups at both ends, exclusively self-assembled into nanotubes with 7–9-nm inner diameters, which consist of a single monolayer lined by polyglycine-II-type hydrogen-bond networks among the triglycine moieties.
Analysis of the AC conductivity, complex dielectric constant, and the resulting immittance spectra of liquid‐phase‐sintered silicon carbide (SiC) ceramics showed that for this system, the dominant experimental observations are due to a multicomponent grain‐boundary phase and not due to SiC grains. This is confirmed by…
Surface enhanced Raman scattering (SERS) in silver nanocolloids and normal Raman spectra (NRS) in the bulk and in aqueous solution of 4-methyl-4 H -1,2,4-triazole-3-thiol (4-MTTL) have been investigated. The observed Raman bands along with the corresponding FTIR bands have been assigned from the potential energy distr…
Abstract Starting from a natural example, several hybrid materials based on silicified collagen were synthesised under ambient conditions. The biomimetic approach and further steps allowed the production of porous as well as dense constructs whose structural assembly was similar to that observed microscopically in the…
We have synthesized two types of novel chiral compounds, D-1 and D-2−D-5, where D-1 is an asymmetric center-containing chiral compound of ( S )-configuration, and D-2−D-5 are so-called double chiral compounds consisting of axially chiral binaphthyl moiety of ( S )-configuration and asymmetric center moieties of ( S )-…
The chirality-dependent combustion of single-walled carbon nanotubes (SWCNTs) during oxidation in both air and hydrogen peroxide was investigated using photoluminescence and Raman spectroscopy. Under air oxidation conditions, SWCNTs with a higher chiral angle and smaller diameter were observed to decompose more rapidl…
Reinforced polyurethane−urea nanocomposite with reactive polyhedral oligomeric silsesquioxanes (POSS) has been prepared via environmentally friendly aqueous dispersion with no organic solvent. Rheological behavior of this important class of materials has been investigated as a function of POSS concentration over a wid…
Sidewalls of acid-treated, shortened single-walled carbon nanotubes (SWNTs) with long alkyl chains at the open ends and defect sites have been functionalized by Bingel reaction to examine the structures and spectroscopic properties in detail for the first time. The microwave-assisted Bingel reaction has been successfu…
A new method for preparing high bending strength porous silicon nitride (Si 3 N 4 ) ceramics with controlled porosity has been developed by using pressureless sintering techniques and phosphoric acid (H 3 PO 4 ) as the pore‐forming agent. The fabrication process is described in detail and the sintering mechanism of po…
Two environmental strains, Delftia acidovorans C17 and Delftia tsuruhatensis A90, were found to carry class 3 integrons, which have seldom been reported and then only from pathogens in which they are associated with antibiotic resistance genes. The Delftia integrons comprised a highly conserved class 3 integrase gene,…
The corrosion inhibition properties of 2-methylimidazoline (MIMD) and N -methyl-2-methylimidazoline (MMIMD) were studied by density functional theory (DFT) and electrochemical methods. The interaction of imidazoline molecules with the iron atoms was studied by DFT as a model for a corrosion inhibition process. DFT res…