Formation of dish-like holes and a channel structure in electrodeposition of copper under hydrogen co-deposition

Copper electrodeposition from acid sulfate solutions at an overpotential of 1000 mV, which is about 250 mV outside the plateau of the limiting diffusion current density, was examined by the determination of the average current efficiency of hydrogen evolution and by the scanning electron microscopic (SEM) analysis of the morphology of the formed copper deposits. Craters or holes formed due to the attachment hydrogen bubbles were the dominant morphological forms of copper deposits obtained at this overpotential. In dependence of the concentration of Cu (II) ions in the plating solution, the two types of holes or craters were formed. One type of holes is obtained by electrodeposition from a solution with a concentration of Cu (II) ions of 0.075 M CuSO₄ in 0.50 M H₂SO₄, and a honeycomb-like structure was formed from these holes. The other types of holes are formed from a solution with a higher concentration of Cu (II) ions (0.60 M CuSO₄ in 0.50 M H₂SO₄) and the formed holes were dish-like. A mixture of both types of holes was obtained by electrodeposition from 0.30 M CuSO₄ in 0.50 M H₂SO₄. The obtained morphologies of copper deposits are discussed in terms of the effect of hydrogen evolution on the hydrodynamic conditions in the plating solution.     

A convenient preparative method of 2,3-dialkyi parasorbic acids from carboxylic acids

Various 2,3-dialkyl parasorbic acids were prepared from carboxylic acids. For example, 2-methyl-5-pentyI parasorbic acid was prepared from hexanoic acid and propanoic acid as follows: Grignard reaction of hexanoic acid ( I ) with allylmagnesium chloride gave l-nonen-4-one ( II ) and the reaction of ( II ) with propanoic acid ( III ) with lithium naphthalenide in the presence of diethylamine produced 3-allyl-3-hydroxy-2-methyloctanoic acid ( IV ). From the reaction of ( IV ) with 97% (v/v) sulphuric acid, 2-methyl-3-pentyl parasorbic acid was formed. Several 2,3-dialkyl parasorbic acids were obtained by this method. These products may be used as perfumery materials.     

Evaluation of the possibility of contamination of sea water by metal ions present in fuel oil

In this study, the reactivity of metal ions that exist in fuel oil with some ligands present either in sea water (inorganic ligands) or in fuel oil (mercaptans and organic acids) were compared based on their formation constants. The values of the formation constants of the metals with the main ligands in water are known. The complexation of the metals Ni(II), V(IV), Fe(II), Cd(II) and Pb(II) with two ligands, hexanoic acid and 1-propanethiol, was studied. These two ligands were chosen to be representative of carboxylic acids and mercaptans present in fuel oil. This study was performed in solution using potentiometry, UV–vis spectrometry and electrothermal atomization atomic absorption. The study of the distribution of species as a function of pH indicated that at approximately pH 8 the most stable species among all metals were those with the oil ligands. An oil spill simulation was also performed and the concentration of the metals was measured in function of time. Theoretical and simulation data alike have shown that the metal ions are retained in fuel oil, even when this oil is spread in the sea.     

Silver–copper electrodeposition from ammonium hydroxide solution: influence of EDTA and HEDTA

The influence of EDTA (ethylenediaminetetraacetic acid, disodium salt) or HEDTA (N-(2-hydroxyethyl)ethylenediaminetriacetic acid, trisodium salt) on silver–copper electrodeposition from ammonium hydroxide solution was investigated. Voltammetric studies showed that silver was deposited at potentials more negative than +0.100 V, while the copper(II) ion was reduced to copper(I) ion and metallic copper at potentials more negative than +0.100 and −0.375 V, respectively. Chronoamperometry, scanning electron microscopy and energy-dispersive X-ray spectroscopy (EDS) indicated that, for deposits obtained at −0.450 V, increasing either the silver content in the silver–copper deposit or the charge density of deposition led to dendritic growth. Moreover, dendritic growth decreased when either the EDTA or HEDTA concentration increased. EDS analysis of the deposits obtained at −0.200 V showed codeposition of copper with silver, which was attributed to Cu(I) ion disproportionation to Cu(0) and Cu(II). Moreover, the silver–copper deposits obtained at −0.200 V, from a solution containing EDTA or HEDTA, were non-dendritic in spite of the high silver content. The presence of EDTA and HEDTA improved the silver–copper morphology. X-ray diffraction analysis indicated that the silver–copper electrodeposit was a supersaturated solid solution.     

Investigation of the surface oxidation of bornite by linear potential sweep voltammetry and X-ray photoelectron spectroscopy

The products of surface oxidation of a natural sample of the copper iron sulphide mineral, bornite, have been determined from analysis of linear potential sweep voltammograms and from X-ray photoelectron spectroscopic examination of the oxidized layer. Anodic oxidation of bornite in alkaline media results initially in the formation of an iron(III) oxide/hydroxide and an iron-free copper sulphide of stoichiometry Cu₅S₄. The latter species is oxidized further at higher potentials to form a copper sulphide of lower copper content and cupric hydroxide. Air oxidation involves the first of these two steps. In acid solution, anodic oxidation yields iron(II) ions rather than an iron oxide in the first stage and copper(II) ions in the second. Sulphate and elemental sulphur are not formed under the experimental conditions investigated.     

Electrochemical growth,in situ optical characterization and photoelectrochemical behaviour of dithio-oxamido copper(II) films

The electrochemical growth of dithio-oxamido copper(II) (copper rubeanate, CuRA) films onto copper electrodes was investigated by voltammetric andin situ optical reflectance techniques and the photoelectrochemical behaviour of the deposits was examined. Copper oxide-free, adherent and uniform deposits are obtained in hydroalcoholic solutions of rubeanic acid by pottential steps from −0.9 to −0.75 Vvs sce up to thicknesses of several hundred manometers. Relatively high photoreduction currents (some % monochromatic quantum yield) are obtained. The presence of copper oxides chemically grown in the CuRA matrix greatly improves both the magnitude and the stability of photoresponses.     

Morphological selection of electroless metal deposits on silicon in aqueous fluoride solution

Well-defined silver and gold dendrites are prepared on silicon substrates in aqueous fluoride acid solution containing AgNO₃ and KAuCl₄, respectively. In cases of electroless platinum and copper deposition in fluoride acid solution, no corresponding metal dendrites but platinum microcrystallines and copper granular-crystallines are formed. Our experiments found that the morphological selection of electroless metal deposits is related to the microstructure of etched silicon. A possible template mechanism and affecting factors for the morphological selection of electroless metal deposits are discussed.     

Adsorption of organic layers over electrodeposited magnetite (Fe3O4) thin films

The formation of monolayers of two organic compounds (oleic acid and dodecanethiol) over magnetite films was studied. Magnetite films ranging from 80 nm to 3.75 μm-thick were electrodeposited on Au on glass substrates under galvanostatic control, with deposition parameters optimized for minimum surface roughness. Films were characterised by SEM and AFM, showing granular deposits with a low rms roughness of 5–40 nm measured over an area of 1 μm². The growth rate was estimated by measuring cross-sections of the thin films. Pure magnetite with an fcc structure is observed in XRD diffractograms. The adsorption of both oleic acid and dodecanethiol on the magnetite films was tested by immersing them in ethanol solutions containing the organic molecules, for different deposition time, temperature and cleaning procedure. Monolayer formation in both cases was studied by contact angle and voltammetric measurements, as well as XPS.     

Production and Emulsifying Effect of Polyglycerol and Fatty Acid Esters with Varying Degrees of Esterification

Esters with acyl groups can be formed by the esterification of polyglycerol. The purpose of the present study was to produce fatty acid esters [hexanoic (caproic), octanoic (caprylic), decanoic (capric), dodecanoic (lauric), tetradecanoic (myristic), hexadecanoic (palmitic), octadecanoic (stearic)] and polyglycerol (average number‐of degrees of polymerization of 5) with varying degrees of esterification and to examine their emulsifying properties. A number of fundamental catalysts of polyglycerol acylation reactions by methyl esters of carboxylic acid were studied, and sodium methoxide was found to be the best choice. The temperature rate of transesterification increased from 180 to 220 °C with the fatty acid chain alkyl residue. Synthesized mono‐, di‐, tri‐, tetra‐, and heptaesters of various fatty acids and polyglycerol provided the highest hydroxyl values from 15 to 815 mg KOH g^?1 and saponification values from 82 to 321 mg KOH g^?1. The emulsifying properties were assessed for all polyglycerol and fatty acid esters, with results showing maximum emulsifying effect for tri‐ and tetraesters of capric, lauric, and caprylic acids. Regardless of the hydrophilic–lipophilic balance value (HLB) of polyglycerol esters and carboxylic acid, a 4:1 ratio of sunflower oil to water formed a water‐in‐oil type emulsion. When mixing oil and water in a 1:1 ratio, mono‐ and diesters of polyglycerol formed an oil‐in‐water type emulsion, heptaesters formed a water‐in‐oil type emulsion, and tri‐ and tetraesters formed both of types of emulsions, depending on the length of the acid hydrocarbon radicals.     

Catalytic effect of the Cu(II)‐ and Fe(III)‐cyclo‐hexanebutyrates on olive oil oxidation measured by Rancimat

In this work the Rancimat technique (temperature 110 °C and air flow 20 l/h) was used in order to test the catalytic effect induced by Cu(II)‐and Fe(III)‐ions on olive oil oxidation. Different amounts of Cu(II)‐ and Fe(III)‐cyclohexanebutyrates were added to a refined olive oil. Copper was shown to be a more active catalyst than iron. In fact, the induction time of the oil was halved by the addition of about 120 ng/g of copper versus 9000 ng/g of iron. The effect of copper and iron was also evaluated on the oil enriched with increasing quantities of caffeic acid (50, 100 and 200 mg/kg). The addition of this phenol induced a significant protective effect which delayed the oxidation of both the control and the oil samples enriched with metals. However, copper‐catalyzed oxidation also in the presence of the antioxidant, thus decreasing the oil oxidative stability approximately three times compared to the control.     

Thermal catalytic cracking of buriti oil (Mauritia flexuosa L.) over LaSBA-15 mesoporous materials

In order to obtain a fuel with properties similar to diesel, the thermal catalytic cracking (TCC) of buriti oil was accomplished over LaSBA-15 mesoporous materials. In function of the Lewis acid sites and the unidirectional pore system of the LaSBA-15, this material presented good deoxygenating activity for TCC of the oil, resulting in a reduction of the oxygenate content in the organic liquid (OL) collected above 190 °C, obtaining as main product, a mixture of hydrocarbons similar to mineral diesel, called green diesel.     

Quantitative Analysis of TAG in Oils Using Lithium Cationization and Direct‐Infusion ESI Tandem Mass Spectrometry

This study was undertaken to determine whether triple‐stage mass spectrometry (MS³) could be employed to obtain quantitative and regioisomeric data from complex oil samples without the need for a chromatographic step in the analysis protocol. Lithium‐7 trifluoroacetate and electrospray ionization were used to form lithium adducts of the triacylglycerols (TAG) in a fish oil sample. The first‐generation precursor ion was the lithium‐TAG adduct, the second‐generation precursor ion was formed by loss of a neutral acid side chain in the first fragmentation. The ions used for analysis were formed in the second fragmentation by loss of the lactones of the acid side chains remaining after the first fragmentation. This analysis scheme provided quantitative and regioisomeric data without interference from TAG in the sample other than TAG with the same acyl carbon number, one more double bond, and two acyl side chains in common with the analyte. Even in this case a majority of the interferences could be estimated and compensated. Analysis of synthetic samples containing the fish oil matrix indicated that both absolute and relative quantitative data could be obtained with average errors of approximately 5 %. The method proved well suited to routine analyses of complex oil samples.     

柴油在氮气存在条件下还原铜渣中磁性铁的模拟

为降低火法冶金炉渣中磁性铁含量以回收铜,采用柴油在N2存在条件下还原铜渣中Fe3O4;并基于吉布斯自由能最小化原理,建立平衡模型,探讨了反应温度（1220～1280℃）、N2加入量（480～960m3/d）、油渣比（0.5～2.9L/t）对Fe3O4还原反应的影响。结果表明：柴油裂解,主要生成C和H2;同时,反应中气体体积发生膨胀。提高反应温度和N2加入量,裂解产物摩尔分数基本保持不变。Fe3O4与柴油裂解产物的反应平衡常数大,反应程度高,Fe3O4被还原成FeO。油渣比增加,Fe3O4还原率呈线性增加。柴油裂解和柴油在氮气存在条件下还原铜渣中Fe3O4反应都是吸热过程。     

Cleaning Ability of Mixed Solutions of Sulfonated Fatty Acid Methyl Esters

Here, we present results from a systematic study on cleaning of oily deposits from solid surfaces (porcelain and stainless steel) by solutions of fatty acid sulfonated methyl esters (SME), sodium salts. The zwitterionic dodecyldimethylamine oxide (DDAO) has been used as a cosurfactant. As representatives of the vegetable and mineral oils, sunflower seed oil and light mineral oil have been used. The process of oil drop detachment from the solid substrates (roll-up mechanism) has been monitored. In the case of porcelain, excellent cleaning of oil is achieved by mixed solutions of SME and DDAO. In the case of stainless steel, excellent cleaning (superior than that by linear alkylbenzene sulfonate and sodium lauryl ether sulfate) is provided by binary and ternary mixtures of SME, which may contain also DDAO. For the studied systems, the good cleaning correlates neither with the oil/water interfacial tension, nor with the surfactant chainlength and headgroup type. The data imply that governing factors might be the thickness and morphology of admicelle layers formed on the solid/water interface. The results indicate that the SME mixtures represent a promising system for formulations in house-hold detergency, having in mind also other useful properties of SME, such as biodegradability, skin compatibility, and hard water tolerance.     

Comparison of particle emissions from an engine operating on biodiesel and petroleum diesel

Biodiesel is an alternative fuel with growing usage in the transportation sector. To compare biodiesel and petroleum diesel effects on particle emissions, engine dynamometer tests were performed on a Euro II engine with three test fuels: petroleum diesel (D), biodiesel made from soy bean oil (BS) and biodiesel made from waste cooking oil (BW). PM_2.5 samples were collected on Teflon and quartz filters with a Model 130 High-Flow Impactor (MSP Corp). Organic (OC) and elemental (EC) carbon fractions of PM_2.5 were quantified by a thermal-optical reflectance analysis method and particle size distributions were measured with an electrical low pressure impactor (ELPI). In addition, the gaseous pollutants were measured by an AMA4000 (AVL Corp). The biodiesels were found to produce 19-37% less and 23-133% more PM_2.5 compared to the petroleum diesel at higher and lower engine loads respectively. On the basis of the carbon analysis results, the biodiesel application increased the PM_2.5 OC emissions by 12-190% and decreased the PM_2.5 EC emissions by 53-80%, depending on the fuel and engine operation parameters. Therefore OC/EC was increased by three to eight times with biodiesel application. The geometrical mean diameter of particles from biodiesels and petroleum diesel had consistent trends with load and speed transition. In all the conditions, there is a shift of the particles towards smaller geometric mean diameter for the biodiesel made from waste oil.     

基于超氧压法考察储备柴油氧化特性研究

采用超氧压法(ASTM D5304)对三种不同类型不同来源储备柴油进行模拟储存试验,通过不同氧化周期、研究酸值、实际胶质含量、运动粘度等理化指标变化趋势,结果表明,在加速氧化条件下,柴油酸值、实际胶质、运动粘度增加,凝固点、闪点、铜片腐蚀理化指标变化较小;三种储备柴油氧化安定性较好,所测理化指标均未超过普通柴油技术标准(GB252)。     

Oxidation and low temperature properties of biofuels obtained from pyrolysis and alcoholysis of soybean oil and their blends with petroleum diesel

Diesel-like fuels were synthesized by a pyrolysis method using soybean oil (pyrodiesel, PD) and soybean soapstock (SPD), respectively, as starting material. These pyrodiesel samples were compared with soy biodiesel (BD) samples. All these three biofuels (PD, SPD and BD) and their blends with high sulfur (HSD) and low sulfur (LSD) diesel fuels were evaluated by measuring a number of fuel properties, such as oxidative stability, low-temperature performance, acid value and corrosion properties. Compared to BD blends, PD and SPD and their blends were found to have better oxidative stability, though inferior acid values. SPD and its blends have better flow performance at low-temperature compared to BD and PD blends. All the biofuels and their blends met the copper corrosion requirement prescribed by US and European standard. Based on the results reported here, pyrodiesels from these two-different feedstocks have potential and will require some upgrading or change in pyrolysis conditions, if they are to be used as fuel blending component.     

Effect of acid dissolution on the mineral matrix and organic matter of Zefa EFE oil shale

Kerogen of the Israeli Zefa oil shale was isolated and the changes which occur in the initial organic matter during the removal of the inorganic matrix were investigated. Benzene-methanol extraction dissolved the bitumens, hydrochloric acid and hydrofluoric acid dissolution removed the carbonate and silicate minerals and lithium aluminium hydride treatment destroyed pyrite mineral which was unaffected by the attack of acids. X-ray diffractograms and FTIR spectra of the original oil shale and its demineralized products were measured. Benzene-methanol extraction of the oil shale increased the resolution of peaks in the X-ray diffractograms X-ray diffractograms and FTIR spectra indicated the presence of calcite, α-quartz, kaolinite, illite and pyrite in the mineral matrix of the shale. Hydrochloric and hydrofluoric acid dissolution did not cause hydrolysis and oxidation of the organic matter. Lithium aluminium hydride treatment reduced the carbonyl functionalities to newly formed hydroxyl groups, therefore the kerogen isolated seemed to have a chemical composition different from that of the original oil shale.     

Microscopic investigation of carbonaceous material forming blockages in coal hydrogenation reactors

Five occurrences of carbonaceous deposits formed in continuous coal or coal tar hydrogenation reactors were examined by optical microscopy with a view to determining the causes of deposit formation. Three of the deposits were formed in helically coiled reactor tubes and the other two in an open tubular reactor operated in the cocurrent upflow mode. It is apparent from the results obtained that the mode of deposition depends, to a large extent, on the nature of the vehicle oil used. In the two cases during which tar and recycle oil were utilized, deposition of carbonaceous materials was gradual. The nature of the deposits indicated that agitation within the reactor was insufficient to prevent settling of mineral matter, catalyst particles and mesophase. The major cause of reactor blockage for the three cases in which tetralin was used as vehicle oil was excessively high reaction temperature.     

Engine performance, exhaust emissions and combustion characteristics of a CI engine fuelled with croton megalocarpus methyl ester with antioxidant

The use of biodiesel as a substitute for petroleum-based diesel has become of great interest for the reasons of combating the destruction of the environment, the price of petroleum-based diesel and dependency on foreign energy sources. But for practical feasibility of biodiesel, antioxidants are added to increase the oxidation stability during long term storage. It is quite possible that these additives may affect the clean burning characteristics of biodiesel. This study investigated the experimental effects of antioxidants on the oxidation stability, engine performance, exhaust emissions and combustion characteristics of a four cylinder turbocharged direct injection (TDI) diesel engine fuelled with biodiesel from croton megalocarpus oil. The three synthetic antioxidants evaluated its effectiveness on oxidation stability of croton oil methyl ester (COME) were 1, 2, 3 tri-hydroxy benzene (Pyrogallol, PY), 3, 4, 5-tri hydroxy benzoic acid (Propyl Gallate, PG) and 2-tert butyl-4-methoxy phenol (Butylated Hydroxyanisole, BHA). The fuel sample tested in TDI diesel engine include pure croton biodiesel (B100), croton biodiesel dosed with 1000 ppm of an effective antioxidant (B100 + PY1000), B20 (20% croton biodiesel and 80% mineral diesel) and diesel fuel which was used as base fuel. The result showed that the effectiveness of the antioxidants was in the order of PY > PG > BHA. The brake specific fuel consumption (BSFC) of biodiesel fuel with antioxidants decreased more than that of biodiesel fuel without antioxidants, but both were higher than that of diesel. Antioxidants had few effects on the exhaust emissions of a diesel engine running on biodiesel. Combustion characteristics in diesel engine were not influenced by the addition of antioxidants in biodiesel fuel. This study recommends PY and PG to be used for safeguarding biodiesel fuel from the effects of autoxidation during storage. Overall, the biodiesel derived from croton megalocarpus oil can be utilized as partial substitute for mineral diesel.