Materials Literature
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The existence of a family of stable I h -symmetric polysilane nanostructures is predicted. The smallest member of the family is the dodecahedral Si 20 H 20 cage, followed by Si 80 H 80, Si 180 H 180, and larger structures. The structures and stabilities of the polysilane nanostructures were determined on the basis of…
In this Letter, we report the confinement of a uniform beam of light (lambda(1) = 400 nm) at the nodes of a standing wave (lambda(2) = 532 nm) via absorbance modulation. In the present implementation of absorbance modulation, a thin polymer film containing a photochromic azobenzene side chain is exposed to a standing…
Abstract Poly(vinyl phenol)‐ block ‐polystyrene (PVPh‐ b ‐PS) diblock copolymers are synthesized by sequential anionic polymerization with sec ‐butyl lithium as the initiator. The PVPh‐ b ‐PS diblock copolymer is cast (on a substrate) from several solvent mixtures that contain tetrahydrofuran/toluene ratios of 1:0.1,…
Abstract A series of X‐ray pole figures were obtained from oriented and unoriented rigid polyvinyl chloride sheets. From these, information about crystallite orientation in uniaxially and biaxially drawn sheets stretched at 90°C was obtained. Uniaxial orientation produced two crystallite orientations with the extent o…
Abstract Surfactant‐free poly(acrylonitrile‐ co ‐styrene)/silica (AS/SiO 2 ) nanocomposite particles was synthesized in the presence of cheap, commercially amorphous aqueous silica sol at ambient temperature. Thermogravimetric analysis (TGA) indicated silica contents ranging from 5 wt % to 29 wt %, depending on reacti…
Abstract The compatibilization of HDPE/LDPE/LLDPE/PET blend during reactive extrusion, using compatibilizing agents, such as modified high, low, and lineal low density polyethylenes with maleic anhydride, was carried out. The agents were prepared in our laboratory by using a UV preirradiation process, containing diffe…
Phase transformation temperature is one of the most important parameters for the shape memory alloys (SMAs). The most popular method to determine these phase transformation temperatures is the Differential Scanning Calorimeter (DSC), but due to the limitation of the DSC testing itself, it made it difficult for the fin…
Abstract Polymer blends of carboxylated butadiene‐acrylonitrile copolymer (nitrile rubber) and polyamide 6 (PA6) were developed in twin screw extrusion. The rubber was cured with SP 1045 methylol phenolic resin during melt mixing in twin screw. Effect of degree of carboxylation in the rubber phase on blend properties…
Abstract Expanded bed adsorption (EBA) is an integrated technology for capturing target biomolecules directly from particle‐containing feedstock. The adsorbents are the key base to achieve the EBA process and should be designed specially. In present work a new type of composite particles for EBA application was prepar…
Abstract A facile approach to polymer nanocomposites with single‐wall carbon nanotubes and cationic polymers is reported. The composite material was synthesized by producing carboxylic acid groups at the nanotube termini followed by a reaction with poly(allylamine) in water. Fourier transform infrared spectral and the…
Novel nanostructured carbon material was synthesized by applying zeolite LTA as a template and using methanol as a carbon source. X-ray diffraction (XRD) revealed that the higher the decomposition temperature, the more graphitic and ordered the structure. The optimum pyrolytic temperature for addition of microporosity…
Isostructural clusters exhibit contrasting magnetic properties when the number of electrons differs. Surprisingly, the same is true even for isoelectronic cages (e.g. O(h) B6H6(2-) is diatropic, whereas O(h) Si6(2-) is paratropic) or for those with different substitutents (e.g. T(d) B4H4 is paratropic, whereas T(d) B4…
Abstract Intumescent coatings are increasingly used as a method of passive fire protection on steel constructions. By forming a carbon network and releasing a blowing agent, the thin intumescent film swells 100‐fold at elevated temperatures. The highly insulating foam effectively prevents the load bearing steel from r…
Abstract The elastic behavior of a propylene–ethylene copolymer was investigated. An initial “conditioning” tensile extension up to 800% strain resulted in an elastomer with low initial modulus, strong strain hardening, and complete recovery over many cycles. Structural changes that occurred in the low crystallinity p…
Powders of BaCe 0.95 Yb 0.05 O 3 - δ were synthesized using the standard solid-state reaction method. The produced materials were characterized by XRD, SEM, and Raman spectrometry. The absorption kinetics of hydrogen was studied using the TA-TQ500 TGA. The XRD study established the following: the phase composition, ce…
Abstract The dynamic mechanical properties of high‐performance polymer matrix composites based on semicrystalline poly(ether ether ketone) (PEEK) and aluminum oxide (Al 2 O 3 ) were evaluated in the temperature range of 30–250°C with a three‐point‐bending mode at a frequency of 1 Hz. The storage modulus and loss modul…
We have re-examined the B-N distance potential of CH3CN-BF3 using MP2, DFT, and high-accuracy multicoefficient methods (MCG3 and MC-QCISD). In addition, we have solved a 1-D Schrödinger equation for nuclear motion along the B-N stretching coordinate, thereby obtaining vibrational energy levels, wave functions, and vib…
A facile synthetic route for the preparation of block copolymer microcapsules with cobalt magnetic nanoparticles (MPs) embedded in the polymer shells is reported. The preparation involved first the Co 2+ reduction to produce cobalt nanocrystals (∼13 nm in size). This was followed by the formation of thin polymeric coa…
The state of gold on a Au/NaY zeolite sample prepared from Au(CH 3 ) 2 (C 5 H 7 O 2 ) and subjected to various treatments was monitored by infrared spectroscopy of adsorbed CO as a probe molecule. Spectra of CO adsorbed on a sample exposed to air and evacuated at room temperature indicate predominantly zerovalent gold…
Abstract PANI nanotubes were successfully prepared by using thin glass tubes as a single template in the presence of H 4 SiW 12 O 40 and ammonium persulfate, which were used as dopant and oxidant, respectively, in this system. The structure and morphology of the PANI were characterized by IR spectrum, XRD pattern, SEM…