Enhancing the electrical and thermal stability of metallic fiber-filled polymer composites by adding tin–lead alloy

This article presents a novel way of greatly enhancing the electrical and thermal stability of copper fiber (CuF)-filled acrylonitrile–butadiene–styrene (ABS) composites via the incorporation of small amount of tin–lead (Sn–Pb) alloy. It was observed that many fibers are soldered together by Sn–Pb, and a continuous CuF/Sn–Pb network is formed throughout the ABS matrix. As a result, the percolation concentration of ABS/CuF composite containing 1 vol% Sn–Pb is lower than for ABS/CuF composite, and the addition of Sn–Pb to the ABS composites containing 5 vol% CuF leads to a further decrease of electrical resistivity compared to ABS/CuF composites with corresponding filler contents. Furthermore, the electrical resistivity of ABS/CuF/Sn–Pb composite shows no temperature dependence, and remains constant during the thermal post-treatment.     

Synthesis and Initial Cell Line Results of Organotin Polyethers Containing Diethylstilbestrol

Organotin polyethers containing the synthetic estrogen diethylstilbestrol have been made in moderate yield with chain lengths ranging from 20 to 200 repeat units employing the interfacial polycondensation procedure. Infrared spectroscopy shows the absence of the O–H group and formation of the Sn–O linkage consistent with the formation of the polyether. F-MALDI MS results are consistent with the presence of organotin-containing fragmentation clusters containing one and two tin atoms and ion fragments up to about 30 units long. The polymers all show moderate to good inhibition of a group of cancer cell lines including colon, breast and prostrate cell lines. Many of them show significant CI₅₀ values showing a preference to inhibit the cancer cell lines in preference to the normal cell lines. This article is dedicated to Professor Astruc.     

Synthesis,Structural Characterization,and Ability to Inhibit Cancer Growth of a Series of Organotin Poly(ethylene glycols)

A series of organotin poly(ethylene glycols) were synthesized including the first water soluble organotin polymers. These products are all polymeric with weight average molecular weights about 10⁵. Infrared spectroscopy shows the presence of moieties from both reactants and the formation of the Sn–O linkage. F MALDI MS shows the presence of up to over a hundred units and by isotopic abundance the presence of one, two, and three tin-containing ion fragments. The polymers inhibit the growth of cancer cell lines from bone, prostate, colon, breast, and lung cancers. In a number of instances chemotherapeutic index values of two and greater are found consistent with these polymers being more active against cancer cells than non-cancerous healthy cells. Thus, some of these polymers show good promise as a new family of anticancer drugs including the water-soluble organotin-containing polymers.     

Selective area deposition of Tin–Nickel alloy coating – an alternative for decorative chromium plating

Sn–Ni alloy coatings on mild steel substrates produced by selective area deposition process with layer thickness of about 14 μm were investigated with regard to the structural and corrosion properties. X-ray diffraction analysis revealed that the selective area plated Sn–Ni alloy was heterogeneous and composed of NiSn, Ni₃Sn₂ and Ni₃Sn₄ phases. Uniform surface coverage of the substrate by granular morphology was observed from SEM and AFM. The alloy composition was determined by X-ray fluorescence (XRF). The corrosion protection performance of Sn–Ni alloy on mild steel was assessed using salt-water immersion and electrochemical corrosion tests. A sharp decrease in I _corr and high charge transfer resistance indicated improved corrosion resistant behavior of the selective area deposited Sn–Ni alloy.     

Investigation of immiscible Sn–Zn coatings with two-layer microstructure as anode material for Li-ion battery

The exfoliation of Sn as a result of volume expansion led to the drastic capacity decay in lithium-ion batteries. In this article, the immiscible Sn–Zn coating was successfully prepared by electrodeposition and applied as the anode material in Li-ion batteries. The physical structure and electrochemical properties were characterized by X-ray diffraction, scanning electron microscope, electron probe microanalysis and charge–discharge test, respectively. The Sn–Zn deposit displayed unique two-layer morphology composed of a Zn flat bottom layer and a Sn dendritic upper layer. The novel Sn–Zn electrodes showed noticeable improvement in cyclability compared to pure Sn film. This improvement was assigned to the characteristic of the two-layer microstructure: the Zn interlayer enhanced the binding strength between Sn dendrites and copper foil; the abundant space among these individual Sn dendrites accommodated the volume expansion during lithiation process. The two-layer Sn–Zn coatings were anticipated as potential anode materials for Li-ion batteries.     

Synthesis,Structural Characterization,and Initial Evaluation as Anticancer Drugs of Dibutyltin Polyamines Derived from Various 4,6-Diaminopyrimidines

A number of diaminopyrimidines have been incorporated into dibutyltin polyamines with molecular weights ranging from 3.5 × 10⁴ to 3.7 × 10⁶ and product yields from 47 to 88%. Infrared spectroscopy is consistent with the inclusion of the diaminopyridines into the polymer backbone with the IR spectroscopy showing the formation of the Sn–N bond as well as the presence of bands from both reactants being present in the polymer. F MALDI MS is also consistent with the products being polymeric and containing units from both the dibutyltin and pyrimidine reactants. The products exhibit good inhibition of cancer cell lines including those derived from human lung, bone, breast, prostrate, and colon cancers. Inhibition occurs within the same concentration range, and lower than that of the most widely employed chemotherapeutic drug, cisplatin.     

Organotin Polyesters from 1,1′-Ferrocenedicarboxylic Acid

Organotin polyesters have been synthesized employing the classical interfacial polycondensation of organotin dihalides and the salt of 1,1′-ferrocenedicarboxylic acid. The products are oligomeric (DP = 5) to polymeric (DP = 220). The presence of new IR bands characteristic of formation of the Sn–O band are present. Ion fragments characteristic of the repeat unit and greater are found employing F MALDI MS.     

The effect of electrochemical lithiation on physicochemical properties of RF-sputtered Sn thin films

Thin films of Sn were deposited on Pt/Si substrates by sputtering technique and subjected to electrochemical lithiation studies. Electrochemical lithiation of Sn resulted in the formation of Sn–Li alloys of different compositions. Charging of Sn-coated Pt/Si electrodes was terminated at different potentials and the electrodes were examined for physicochemical properties. The scanning electron microscopy and atomic force microscopy images suggested that the Sn films expanded on lithiation. Roughness of the film increased with an increase in the quantity of Li present in Sn–Li alloy. Electrochemical impedance data suggested that the kinetics of charging became sluggish with an increase in the quantity of Li in Sn–Li alloy.     

The role of water in ethanol oxidation over SnO2-supported molybdenum oxides

The role of water in the oxidation of ethanol to acetic acid on Sn–Mo–O catalysts was studied by catalytic test and FTIR spectroscopy of adsorbed species. The reaction showed a typical behavior of series reactions involving oxidation of ethanol to acetaldehyde and of the latter to acetic acid and CO₂. Addition of water to the feed gas decreased the oxidation rate and significantly increased the selectivity to acetic acid, strongly contributing to decreasing the number of secondary products. FTIR analyses showed that water promotes desorption of ethanol and carboxylates, present as bridging and monodentate species. Decreasing catalytic rate values and increasing selectivity to acetic acid in the presence of water follow from site blocking by hydroxyl groups. This revised version was published online in July 2006 with corrections to the Cover Date.     

High-performance Sn–Ni alloy nanorod electrodes prepared by electrodeposition for lithium ion rechargeable batteries

To reduce irreversible capacity and improve cycle performance of tin used in lithium ion batteries, Sn–Ni alloy nanorod electrodes with different Sn/Ni ratios were prepared by an anodic aluminum oxide template-assisted electrodeposition method. The structural and electrochemical performance of the electrode were characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, cyclic voltammetry, and galvanostatic charge–discharge cycling measurement. The results showed that the copper substrate is covered with uniformly distributed Sn–Ni alloy nanorods with an average diameter of 250 nm. Different phases (Sn, Ni₃Sn₄ and metastable phases) of alloy nanorod formed in the electrodeposition baths with different compositions of Sn²⁺ and Ni²⁺ ions. Sn–Ni alloy nanorod electrode delivered excellent capacity retention and rate performance.     

Oxidation of glycerol with hydrogen peroxide using silicalite and aluminophosphate catalysts

The oxidation of glycerol using a range of metal‐containing silicalite and aluminophosphate catalysts is described and discussed. Variation in reaction conditions (extent of conversion, temperature, glycerol/hydrogen peroxide ratio) or catalyst (silicalite containing Ti, V, Fe or AlPO‐5 containing Cr, V, Mn, Co) did not lead to the formation of partial oxidation products of glycerol. Formic acid and a mono‐formate ester of glycerol were observed to be the major products together with a complex mixture of acetals. Increasing the pore size of the catalyst was investigated for Ti‐containing materials and it was found that increasing the pore size from ca. 0.5 nm for TS‐1 to 15 nm for a titania–silica co‐gel significantly increased the formation of partial oxidation products of glycerol, namely glyceraldehyde, dihydroxyacetone and glyceric acid. This revised version was published online in July 2006 with corrections to the Cover Date.     

Press-Molding of High-Alumina Ceramic Castables. 1. Compaction and Properties of Matrix Systems Based on Mixed HCBS of Composition: Bauxite,Quartz Glass,and Commercial Alumina

Preparation of powders based on bauxite HCBS (Highly Concentrated Ceramic Binding Suspensions) containing high-disperse quartz glass and plasticized with refractory clay is described. The powders, molded at moderate pressure (50 – 100 MPa), give a high-density material with an initial porosity of 20 – 25%. Mixes containing 10 to 43% commercial alumina are tested. The materials can be used as matrices for press-molded high-alumina ceramic castables which, when sintered, show a high mechanical strength and volume constancy. __________ Translated from Novye Ogneupory, No. 5, pp. 39 – 44, May, 2005.     

Active Catalysts for the NO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> Reduction in a FCC unit

Additives, without noble metals, based in Ce–Al mixed oxides supported on γ-alumina have been investigated as potential catalysts for the NO _x reduction in the FCCU regenerator. The best results were obtained with clusters of Sn–Cu–Al–O interacting with Ce–Al mixed oxides highly dispersed on the γ-Al₂O₃. The strong interaction between the two complex oxides provides a stable catalyst with high activity at high temperature. These additives would be active in the dense phase of the FCC regenerator, being deactivated at oxygen concentrations higher than 2%, but they would be regenerated in the FCC reactor. A. Uzcátegui is in leave to Laboratorio de cinética y catálisis del Departamento de Química, Facultad de Ciencias, Universidad de los Andes, La Hechicera, Merida, Venezuela.     

Synthesis, Structural Characterization, and Preliminary Biological Characterization of Organotin Polyethers Derived from Hydroquinone and Substituted Hydroquinones

A variety of dibutyltin polyethers have been synthesized employing the interfacial polymerization technique. The products are polymers with degrees of polymerization ranging from 60 to 390. Infrared spectral and mass spectral results are consistent with the proposed structure. The products show good inhibition of a variety of cancer cells including those associated with bone, breast, prostrate, and lung cancers. Some also show good viral inhibition of the HSV-1 (herpes simplex) and Vaccina (small pox) viruses with those derived from electron rich hydroquinone derivative being most active. Hydroquinone-derived polymers containing electron withdrawing groups exhibit inhibition of a variety of gram positive and gram negative bacteria.     

Electrochemical co-deposition of ternary Sn–Bi–Cu films for solder bumping applications

This paper reports the co-deposition of Sn–Bi–Cu films using stannic salt bath which has good stability for up to a week. The effect of current density and bath stirring on the film composition and microstructure has been studied. The deposited films are rich in the more noble metal Bi at current densities up to 5 mA cm⁻² but stabilize to about 49 wt. % Bi, 47 wt. % Sn and 4 wt. % Cu at 10 mA cm⁻² and beyond, indicating the effect of limiting current density. There is improvement in the microstructure with stirring or aeration, but the film composition reverts to the Bi rich state, with close to 90 wt. % Bi for deposition at 5 mA cm⁻². This is attributed to the dispersion of Sn²⁺ ions generated at the cathode during the two-step reduction of Sn⁴⁺ ions, due to stirring. The bath is suitable for near eutectic compositions of Sn–Bi with <5 wt. % Cu content.     

Zn–Sn electrodeposition from deep eutectic solvents containing EDTA,HEDTA, and Idranal VII

The use of deep eutectic solvents for metal electrodeposition has become an area of interest in the recent years. In this study, ethaline, propeline, and reline were used as solvents for the electrodeposition of Sn–Zn alloys. Ethaline, propeline, and reline displayed identical voltammetric profiles for the reduction of Zn(II) and Sn(II). Further studies were carried out in ethaline which is the liquid with lowest viscosity. To improve physical and morphological properties of the Sn–Zn deposits, additives were added to the ionic liquid solution. In this study, the addition of three chelators (EDTA, HEDTA, and Idranal VII) and their effects on the voltammetric behavior of zinc and tin and the resultant morphology was described. The structure and composition of the Zn–Sn deposit was largely affected by the additives with the largest effect being obtained in the presence of Idranal VII.     

Novel Sn–Ce/Al2O3 Catalyst for the Selective Catalytic Reduction of NOx Under Lean Conditions

Effect of additives, Ce and Mn, on the catalytic performance of Sn/Al₂O₃ catalyst prepared by sol–gel method for the selective reduction of NO_x with propene under lean conditions was studied. Sn–Ce/Al₂O₃ catalysts exhibited higher activity than Sn/Al₂O₃ catalyst and the optimum Ce loading is 0.5–1%. The promoting effect of Ce is to enhance the oxidation of NO to NO₂ and facilitate the activation of propene, both of which are important steps for the NO_x reduction. The presence of oxygen contributes to the oxidation of NO and shows a promoting effect.     

Effect of Ni in palladium <Emphasis Type="Italic">β</Emphasis>-zeolite on hydroisomerization of <Emphasis Type="Italic">n</Emphasis>-decane

Bifunctional catalysts containing (0.1–0.5 wt%) Nickel and 0.1 wt% of Pd supported on H-β zeolite were synthesized by incipient wetness impregnation method and characterized by XRD, TEM, XPS, TPD and TPR techniques. The catalytic activity of Ni containing and Ni free Pd/H-β Catalysts was studied, and it was found that Ni up to a threshold value (0.3 wt% on β) produced increased the n-decane conversion and isomerization selectivity. When Ni content exceeds the threshold value, the conversion increases but isomerized products decrease. Moreover, Ni containing Pd/H-β showed increased sustainability and favored the protonated cyclopropane (PCP) intermediate mechanism in n-decane isomerization. The catalyst containing 0.3 wt% Ni 0.1 wt% Pd is adjudged as one performing better than other catalysts studied because of the isomerized mixture from it shows better octane number.     

High pressure liquid chromatography of autoxidized lipids: II. Hydroperoxy-cyclic peroxides and other secondary products from methyl linolenate

A previous study of autoxidation products by high pressure liquid chromatography (HPLC) of methyl oleate and linoleate was extended to methyl linolenate. Autoxidized methyl linolenate was fractionated by HPLC either after reduction to allylic alcohols on a reverse phase system, or directly on a micro silica column. Isolated oxidation products were characterized by thin layer and gas liquid chromatography and by ultraviolet, infrared, nuclear magnetic resonance and mass spectrometry. Secondary products from the autoxidation mixtures (containing 3.5–8.5% monohydroperoxides) included epoxy unsaturated compounds (0.2–0.3%), hydroxy or hydroperoxy-cyclic peroxides (3.8–7.7%), epoxy-hydroxy dienes (<0.1%), dihydroxy or dihydroperoxides with conjugated diene-triene and conjugated triene systems (0.9–2.9%). Cyclization of the 12- and 13-hydroperoxides of linolenate would account for their lower relative concentration than the 9- and 16-hydroperoxides. Dihydroperoxides may be derived from the 9- and 16-linolenate hydroperoxides. Cyclic peroxides and dihydroperoxides are suggested as important flavor precursors in oxidized fats.     

Low-<Emphasis Type="Italic">trans</Emphasis> Shortening and Spread Fats Produced by Electrochemical Hydrogenation

Partially hydrogenated soybean oils (90–110 IV) were prepared by electrochemical hydrogenation at a palladium/cobalt or palladium/iron cathode, moderate temperature (70–90 °C) and atmospheric pressure. The trans fatty acid (TFA) contents of 90–110 IV products ranged from 6.4 to13.8% and the amounts of stearic acid ranged from 8.8 to 15.4% (the higher stearic acid contents indicated that some reaction selectivity had been lost). The solid fat values and melting point data indicated that electrochemical hydrogenation provides a route to low-trans spreads and baking shortenings. Shortenings produced by conventional hydrogenation contain 12–25% trans fatty acids and up to 37% saturates, whereas shortening fats produced electrochemically had reduced TFA and saturate content. Electrochemical hydrogenation is also a promising route to low-trans spread and liquid margarine oils. Compared to commercial margarine/spread oils containing 8–12% TFA, the use of electrochemical hydrogenation results in about 4% TFA. Names are necessary to report factually an available data: the USDA neither guarantees nor warrants the standard of the product, and the use of the name USDA implies no approval of the product to the exclusion of others that may also be suitable.