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A series of alkyl esters (methyl, butyl, hexyl, and octyl) synthesised from a mixture of 4- and 5-carboxybenzotriazole (4-CBTAH and 5-CBTAH) inhibited copper corrosion in aerated solution (pH∼0). Inhibition efficiency (IE%) of the protonated esters (CBTAH2+-R) increased with hydrocarbon chain length and this is attributed to chemisorption (through azole ring N) and increased physical adsorption as more methyl groups are introduced. A modelling package employing molecular mechanics and molecular dynamics has been used to simulate the docking of a single protonated species (5-CBTAH2+-R) onto a clean copper (1 1 0) surface. A decrease in potential energy was associated with the flattening of the ester ring system onto the surface and further decreases in energy were associated with the extension of the aliphatic chain onto the surface. The crude binding energy (Ebind) of each ester with the surface was estimated and this energy also increased regularly with carbon chain length. The study suggests that molecular modelling and calculation of Ebind of a single molecule on a specified metallic surface can be used to predict the inhibition performance of compounds whose structures change in a regular way. 相似文献
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Polar pollutants in municipal wastewater and the water cycle: Occurrence and removal of benzotriazoles 总被引:4,自引:0,他引:4
1H-benzo-1,2,3-triazole (BTri) and its methylated analogues (tolyltriazole, TTri) are corrosion inhibitors used in many industrial applications, but also in households in dishwashing agents and in deicing fluids at airports and elsewhere. BTri and one of the TTri-isomers (4-TTri) are typical examples of polar and poorly degradable trace pollutants. Benzotriazole elimination in four wastewater treatment plants (WWTP) in Berlin ranged from 20 to 70% for 5-TTRi over 30 to 55% for BTri to insignificant for 4-TTri. WWTP effluent concentrations were in the range of 7-18 μg/L of BTri, 1-5 μg/L of 4-TTri and 0.8-1.2 μg/L of 5-TTri. BTri and 4-TTri proved to be omnipresent in surface waters of the rivers Rhine and Elbe with concentrations increasing from <0.05 μg/L to around 0.5 μg/L of BTri and 0.2-0.5 μg/L of 4-TTri over 600-700 km. Bank filtration is an important process to generate raw water for drinking water production from surface waters. Even after residence times of several months BTri and 4-TTri were determined in concentrations of a few hundred ng/L in bank filtration water. Isotherm data from batch experiments indicate that activated carbon filtration should be suitable to avoid intrusion of TTri into drinking water in partially closed water cycles. For BTri, however, sorption to activated carbon appears to be too weak and ozonation may be mandatory to remove it from raw waters. 相似文献
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The effects of thiourea and benzotriazole on the hydrogen permeation into iron were studied using a Devanathan-Stachurski electrochemical double cell equipped with a thin iron membrane. Hydrogen was cathodically generated on the entry side and fully oxidized on the exit side. The spectral analysis of both the electrochemical impedance on the entry side and the permeation transfer function between the ac current signals on the two faces of the membrane were recorded according to a method recently proposed. The modifications of the impedance diagrams and the transfer function diagrams induced by the presence of the organic additives were interpreted at the light of the mechanistic model of the transfer function which was recently derived. It is concluded that both additives inhibit the hydrogen evolution reaction, but thiourea promotes hydrogen penetration by inhibiting the recombination reaction, whereas benzotriazole adsorption inhibits the formation of the Hads and therefore their penetration into the metal matrix. 相似文献
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Anton Kokalj 《Electrochimica acta》2010,56(2):745-755
The often used approach in the corrosion inhibition studies employing quantum chemical calculations that relies on the correlation between molecular electronic structure parameters and inhibition effectiveness is critically examined. It is shown that the inhibition performance of three selected triazole-based corrosion inhibitors for copper - 3-amino-1,2,4-triazole (ATA), benzotriazole (BTAH), and 1-hydroxybenzotriazole (BTAOH) - cannot be explained on this basis in a sound manner. As the effectiveness of inhibitors is due to several phenomena, the outcome depends on the interplay between them and although molecular electronic parameters may provide many necessary elements, the involved effects can be estimated only approximately which may not always suffice. This supports the proposition that in general molecular electronic properties cannot be directly related to inhibition effectiveness - the actual relation is more involved - thus emphasizing the importance of a rigorous modeling of the inhibitor-surface interaction in the corrosion inhibition studies. 相似文献
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Occurrence, distribution and fluxes of benzotriazoles along the German large river basins into the North Sea 总被引:1,自引:0,他引:1
Benzotriazole (BT) and tolyltriazole (TT) are high production volume chemicals which are used in various industrial and household applications. In this study, the distribution of benzotriazoles in the estuaries of different rivers of central Europe and in the North Sea was analyzed by solid-phase extraction (SPE) and liquid chromatography-mass spectrometry (HPLC-MS/MS). BT as well as TT was detected in all water samples. The concentrations for total benzotriazoles (BTs) ranged from 1.7 to 40 ng/L in the North Sea in costal areas. Concentrations in rivers are from 200 to 1250 ng/L, respectively. The mass flux of total benzotriazoles from the major rivers of central Europe into the North Sea was calculated to 78 t/a, dominated by the Rhine with an individual flux of 57 t/a of BTs. The analysis of the distribution profile in the North Sea showed that the decrease of the concentration was mostly caused by dilution and that the benzotriazoles are poorly degradable in the North Sea. This paper presents the first report of benzotriazoles in the marine environment. 相似文献
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The potentiodynamic anodic polarization curve of α-brass (70% Cu-30% Zn) in 1 M LiBr solution showed an initial active region of the alloy dissolution followed by two well defined anodic current peaks then a narrow passivation region before the pitting potential (Epit) is reached. The initial active anodic region exhibited Tafel slope with 90 mV dec−1 attributed to the formation of CuBr2− complexes. The anodic current peaks were attributed to the formation of CuBr and Cu2+ ions, respectively. The change of pH values of LiBr solution did not affect the anodic polarization curves of α-brass. Increasing the solution temperature from 30 to 90 °C changed the corrosion type from pitting to general one. The addition of 10−2 M benzotriazole (BTAH) to 1 M LiBr solution is completely inhibited the pitting corrosion at 30 °C while it did not inhibit the pitting at 90 °C. The inhibition effect was attributed to the adsorption of BTAH molecules on the alloy surface, which obeys Langmuir isotherm. The presence or absence of pitting corrosion was confirmed by using SEM. 相似文献
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苯并三唑类紫外线吸收剂的研究进展 总被引:3,自引:0,他引:3
论述了应用最广泛的紫外线吸收剂苯并三唑类化合物在提高消光系数、引入可聚合基团以及和其它光稳定剂如受阻胺光稳定剂的协同作用等方面的研究进展。 相似文献
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The nature of the protective film formed by benzotriazole (BTAH) on the surface of the 90/10 CuNi alloy in deaerated 0.5 mol L−1 H2SO4 solution containing Fe(III) ions as oxidant was investigated by weight-loss, calorimetric measurements, and by surface-enhanced Raman spectroscopy (SERS). The SERS measurements show that the protective film is composed by the [Cu(I)BTA]n polymeric complex and that the BTAH molecules are also adsorbed on the electrode surface. A modification of the BET isotherm for adsorption of gases in solids is proposed to describe the experimental results obtained from weight-loss experiments that suggest an adsorption in multilayers. Electrochemical studies of copper and nickel in 0.5 mol L−1 H2SO4 in presence and absence of BTAH have also been made as an aid to interpret the results. The calculated adsorption free energy of the cuprous benzotriazolate on the surface of the alloy is in accordance with the value for pure copper. 相似文献