ICP-AES Analysis Research Articles

Multiple approaches for heavy metal contamination characterization and source identification of farmland soils in a metal mine impacted area

Heavy metal and metalloid contamination of farmland soils are closely related to human health. Soil contamination caused by small-scale mining activities has been largely neglected, especially in developing countries. This research studies the characteristics and the source of heavy metals and metalloids in farmland soils in the Bailing Cu–Zn deposit area in Northeastern China through multiple approaches. Geochemical mapping conducted by portable X-ray fluorescence (pXRF) spectrometry and elemental fractionation analysis (sequential extraction) revealed the spatial variations in elemental concentration and fractionation of the farmland soils. The elemental variations in the sediment and water samples in a stream passing by the farmland were determined by inductively coupled plasma mass spectroscopy (ICP-MS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis. Results indicate elevated As, Zn, Fe, and Mn concentrations in the west bank of the farmland and the associated environmental risks caused by extremely high As concentrations (>500 mg kg−1). The upstream mining activities are identified as a dominated source of contamination in the studied farmland based on the variations of elemental concentrations and fractionations, as well as multivariate analysis results. This study revealed potential ecological risks caused by heavy metal and metalloid contamination in farmland soils in the metal mine impacted area and the stream as a primary pathway for the migration of pollutants associated with mining activities.

Assessing heavy metal contamination in a Brazilian metropolis: a case study with a focus on (bio)indicators.

The continuous expansion of the global vehicle fleet poses a growing threat to environmental quality through heavy metal contamination. In this scenario, monitoring to safeguard public health in urban areas is necessary. Our study involved the collection of 36 street dust and 29 moss samples from roads of a Brazilian metropolis (Recife) with varying traffic intensities as follows: natural reserve (0 vehicles per day), low (< 15,000 vehicles per day), medium (15,000-30,000 vehicles per day), and high (> 30,000 vehicles per day). ICP-AES analysis was performed to determine the concentrations of nine potentially toxic metals (Ba, Cd, Cr, Cu, Mn, Ni, Pb, V, and Zn) to assess the influence of vehicular flow on urban contamination. In the street dust samples, the mean metal concentrations (mg kg-1) exhibited the following order: Ba (503.7) > Mn (303.0) > Zn (144.4) > Cu (95.3) > Cr (56.1) > Pb (34.2) > V (28.7) > Ni (11.3) > Cd (1.5). Conversely, in the moss samples, the metal concentration order was as follows (mg kg-1): Mn (63.8) > Zn (62.5) > Ba (61.0) > Cu (17.7) > Cr (8.0) > V (7.3) > Pb (7.0) > Ni (2.9) > Cd (0.3). Roads with higher traffic volumes exhibited the highest metal enrichments in moss samples for all metals and in dust samples for Cd, Cr, Mn, Ni, and V. However, dust from low-flow roads had higher enrichments for Ba, Cu, and Zn, indicating the influential role of other traffic-related factors in metal deposition. Our findings highlight traffic flow as the predominant source of pollution in urban centers, with both street dust and moss serving as sensitive indicators of metal input attributable to vehicular traffic. These indicators offer valuable insights for urban quality monitoring and pollution control efforts.

A Siderophore Mimicking Gelation Component for Capturing and Self-Separation of Fe(III) from an Aqueous Solution of Mixture of Metal Ions.

The carbohydrazide-based gelation component N2,N4,N6-(1,3,5-triazine-2,4,6-triyl)tris(benzene-1,3,5-tricarbohydrazide) (CBTC) was synthesized and characterized using various spectroscopic tools. CBTC and trimesic acid (TMA) get self-assembled to form metallogel with Fe3+, specifically through various noncovalent interactions in a DMSO and H2O mixture. The self-assembly shows remarkable specificity toward Fe(III) among different transition metal salts. It is pertinent to point out that the binding specificity for Fe3+ can also be found in nature in the form of siderophores, as they are mainly involved in scavenging iron selectively from the surroundings. DFT studies have been used to investigate the possible interaction between the different components of the iron metallogel. To determine the selectivity of CBTC for iron, CBTC, along with trimesic acid, is used to interact with other metal ions, including Fe(III) ions, in a single system. The gelation components CBTC and TMA selectively bind with iron(III), which leads to the formation of metallogel and gets separated as a discrete layer, leaving the other metal ions in the solution. Therefore, CBTC and TMA together show iron-scavenging properties. This selective scavenging property is explored through FE-SEM, XPS, PXRD, IR, and ICP-AES analysis. The FE-SEM analysis shows a flower-petal-like morphology for the Fe(III) metallogel. The resemblance in the CBTC-TMA-Fe metallogel and metallogel obtained from the mixture of different metal salts is established through FE-SEM images and XPS analysis. The release of iron from the metallogel is achieved with the help of ascorbic acid, which converts Fe3+ to Fe2+. In biological systems, iron also gets released similarly from siderophores. This is the first report where the synthesized gelation component CBTC molecule is capable of scavenging out iron in the form of metallogel and self-separating from the aqueous mixture in the presence of various other metal ions.

Siderophore of plant growth promoting rhizobacterium origin reduces reactive oxygen species mediated injury in Solanum spp. caused by fungal pathogens.

The study aims to explore antifungal properties of bacillibactin siderophore produced by the plant growth-promoting rhizobacterium (PGPR) Bacillus subtilis against fungal phytopathogens Alternaria porri and Fusarium equiseti isolated from Solanum lycopersicum and Solanum melongena plants. Alternaria porri and F. equiseti were isolated from infected plants of eggplant and tomato, respectively. A plate assay was employed to assess the effect of bacillibactin against the phytopathogens. The antifungal potential of the PGPR was evaluated by estimation of dry fungal biomass, visualization of cellular deformity using compound and scanning electron microscopy, antioxidative enzyme assay and analysis of membrane damage via using lipid peroxidation. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis was employed to investigate changes in intracellular iron content. The impact of bacillibactin on pathogenesis was evaluated by infecting detached leaves of S. lycopersicum and S. melongena plants with both the pathogens and treating the infected leaves with bacillibactin. Leaves were further investigated for ROS accumulation, extent of necrosis and cell death. Our findings revealed significant damage to the hyphal structure of A. porri and F. equiseti following treatment with bacillibactin. Biomass reduction, elevated antioxidative enzyme levels, and membrane damage further substantiated the inhibitory effects of the siderophore on fungal growth. ICP-AES analysis indicates an increase in intracellular iron content suggesting enhanced iron uptake facilitated by bacillibactin. Moreover, application of 1500µg ml-1 bacillibactin on infected leaves demonstrated a substantial inhibition of ROS accumulation, necrosis, and cell death upon bacillibactin treatment. This study confirms the potent antagonistic activity of bacillibactin against both the phytopathogens A. porri and F. equiseti growth, supporting its potential as a promising biological control agent for fungal plant diseases. Bacillibactin-induced morphological, physiological, and biochemical alterations in the isolated fungi and pathogen-infected leaves highlight the prospects of bacillibactin as an effective and sustainable solution to mitigate economic losses associated with fungal infections in vegetable crops.

Pivotal Adsorption of Heavy metal ion by Marvelous Carbon Nanomaterials Impregnated with Nanometal synthesized from Agro-waste Cauliflower Leaves

Abstract: Nanoparticles, with a diameters upto100nm, exhibit a heightened surface-to-volume ratio which allows a greater participation of active surface atoms, fostering improvements in material properties and enhancing implementation. The current work involves acquisition of abundantly, non-edible, and easily available agro-waste cauliflower leaves; pyrolyzed in an inert atmosphere at particular temperature to generate carbon materials. Additionally, the material is activated by using definite concentration of alkali solution followed by impregnation of copper metal and processed with annealing to obtain a desire adsorbent carbon nanomaterial. Adsorption of heavy metal ions [Ag(I)] at pH 6 gives significant result of 96% verified by ICPAES analysis. Characterization as well as morphology of adsorbent was examined through SEM and HR-TEM. Moreover, XRD revealed the presence of graphitic and amorphous carbon whereas BET prominently explained the specific surface area, pore volume and porosity of the synthesized carbon nanomaterial impregnated with copper nanometal.

Preliminary evaluation of zeolite-based platforms as potential dual drug delivery systems against microbial infections in the tumor microenvironment

Several zeolite-based delivery systems (ZDS) built with faujasite structure were prepared containing silver (Ag+) and 5-Fluorouracil (5-FU) as antimicrobial and antineoplastic agents, respectively. The idea behind this drug combination is an answer to the increasing evidence of colonization of tumor microenvironments by pathogenic microorganisms and their active role in tumor growth. Two ZDS with a fixed load of 5-FU and different silver loads, Ag7(5-FU)@Y and Ag4(5-FU)@Y, were prepared through ion-exchange of silver followed by 5-FU encapsulation in liquid phase. The developed ZDS were characterized in-depth by scanning microscopy (SEM), thermogravimetric analysis (TGA), N2 adsorption analysis, ICP-AES analyses and X-ray photoelectron spectroscopy (XPS), and successfully confirmed the incorporation of both drug-active species into the zeolite framework without inducing structural alteration. Finally, the antimicrobial properties of the ZDS were investigated against various strains of bacteria. ZDS containing both drug-active species - Ag and 5-FU - displayed lower Minimum Inhibitory Concentration (MIC) values than AgxY, indicating higher effectiveness in inhibiting bacterial growth. Ag4(5-FU)@Y resulted to be the most favourable combination exhibiting efficient encapsulation of 5-FU while containing an efficient amount of silver.

Preparation and characterization of Pd (II) based on 2,5-pyridinedicarboxylic acid as novel recyclable metal-organic frameworks for Suzuki–Miyaura reaction

A novel recyclable metal-organic framework (MOF) based on Pd(II) and 2,5-Pyridinedicarboxylic acid ([Pd/PDCA]n) was synthesized and characterized by different methods such as FT-IR, XRD, SEM, EDX, TGA and ICP-AES analysis. The [Pd/PDCA]n catalyst was used as a heterogeneous catalyst in the Suzuki–Miyaura reaction on to prepare biaryl derivatives from aryl halides (1 mmol) with arylboronic acids (1.5 mmol) and 0.1 g of K2CO3 in DMF (10 mL) solvent conditions at 110 °C in about 15 min with a 96 % yield and reusable MOF for the efficient preparation of biaryl derivatives through Suzuki–Miyaura reaction in an eco-friendly system. The catalyst displayed excellent yields and catalytic efficiency compared to other catalysts, and it was found to be recoverable and reusable without losing its activity after several cycles. This study presents a new approach for the sustainable preparation of biaryl derivatives using a reusable catalyst. The structure of the synthesized products was confirmed by NMR analysis and melting point.

Electrochemical Oxygen Evolution from Metal Oxides Using Perovskite Anodes Towards Lunar Resource Utilization

In-situ resource utilization (ISRU) has been proposed for realizing sustainable lunar development. One of the representative resources on the Moon is lunar regolith, which covers the lunar surface. The chemical composition of lunar regolith resembles the constituents of the Earth: silica (SiO2) is the most abundant oxides in the lunar regolith. Silicon, which can be produced by silica reduction, will be the material for solar cells, and oxygen is essential for manned space exploration. Enormous amounts of silicon and oxygen will be obtainable on the Moon without transportation from the Earth by establishing silicon reduction methods without consumables. However, the conventional silica reduction method consumes vast amounts of carbon, which cannot be mined on the Moon.For realizing carbon free silica reduction method consistent with the concept of ISRU, molten salt electrolysis processes using perovskite anodes has been researched. In this method, the silica dissolved in molten salts is electrolyzed using voltage with passage of direct current through electrodes, which generate oxygen gas and silicon by the electrochemical process. The perovskite oxides have high electrical conductivity and oxidation resistance. Therefore, the perovskite anodes have been expected as oxygen generation inert anodes.In this study, we report the characteristics of perovskite-type anodes for oxygen generation measured in the electrolysis experiments. In molten fluoride containing silica at a temperature over 500℃, the measured cyclic voltammograms with a perovskite-type anode show drastically increases of current density at 2.6 V vs K+/K, which was approximately same to the oxygen generation potential in the previous molten salt electrolysis result without the perovskite anodes. The characteristics of perovskite-type anodes for oxygen generation will be discussed from the results of electrochemical measurements and chemical analysis using XRD, SEM, EDX, and ICP-AES analysis.

A new bio-oxidation method for removing iron deposits from waterlogged wood of Nanhai I shipwreck, Guangdong, China

The widespread presence of iron and sulfur compounds such as pyrite in marine waterlogged archeological wood (WAW) can cause irreversible damage to the safety of its preservation. This issue has been a longstanding concern for cultural heritage conservation communities. In this study, we examined the distribution and phase composition of Fe and sulfur compounds in wood samples obtained from the Nanhai I shipwreck using ESEM-EDS, micro-Raman spectroscopy, and an X-ray diffractometer. The removal of iron from WAW samples of the Nanhai I shipwreck using Acidithiobacillus ferrooxidans (A. ferrooxidans) was evaluated using conductivity and ICP-AES analysis. The results showed that A. ferrooxidans effectively improved the removal of iron from WAW. The degradation of fresh healthy wood during treatment was also analyzed using infrared spectroscopy, and the results showed that the treatment had little effect on the samples over a short period. This study demonstrates, for the first time, the feasibility of iron extraction from marine WAW by A.ferrooxidans. This was also the first attempt in China to apply biological oxidation to the removal of iron from marine archeological materials.

Interaction between Armenian clay-based ceramics and model wine during storage

Wine made or stored in clayware ceramic pots attracts the attention of consumers, but this practice is less studied than when classic stainless steel tanks or wood barrels are used. It is known that wine can be influenced by the container in which it is aged. To analyse the influence of ceramics on the chemical composition of wine, Armenian clay-based ceramic tablets were immersed in model wine and aged from 1 hour up to 16 months at 25 °C in darkness. The concentrations of 26 elements (namely: Al, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sr, Ti, V, W and Zn) in 19 samples were determined by ICP-AES analysis. Proton time domain NMR relaxometry was used to characterise the iron redox processes that occurred in the model wine in contact with a ceramic. A fast increase in the pH of the model wine in contact with the bare ceramic tablet (from 2.35 to 5) was recorded in 4 days. The coating of the ceramic tablets with beeswax showed a significant effect on the interaction between the model wine and the ceramic.

The Potential of Waste Phloem Fraction of Quercus cerris Bark in Biochar Production

Quercus cerris phloem is a lignocellulosic waste fraction obtained from bark fractionation. Biochars are technologically interesting functional materials that may be produced from lignocellulosic solid materials. This study explores the solid material properties of Quercus cerris phloem, evaluates biochar production from it, and explores its application as an adsorbent. In the first part of the study, thermogravimetric analysis, SEM microscopy observations, FT-IR spectroscopy, and ICP-AES analyses were performed on raw Quercus cerris phloem. In the second part of the study, biochars and activated carbons were produced and their structure, surface functional groups, methylene blue adsorption properties, and specific surface areas were determined. The results showed that Quercus cerris phloem is a lignocellulosic solid material that decomposes in a wide temperature range between 265 and 765 °C. The activation energy of phloem pyrolysis ranged between 82 and 172 kJ mol−1 in pyrolysis. The mineral composition is mainly calcium (88%) and potassium (4%). The biochar yield of Quercus cerris phloem ranged between 28% and 42% at different moderate temperature–time combinations. Raw phloem, phloem biochars, and phloem-activated carbons show high methylene blue removal efficiencies. Methylene blue adsorption follows pseudo-second-order kinetics. The BET surface areas of Quercus cerris phloem-activated carbons varied between 262.1 m2 g−1 and 317.5 m2 g−1.

Extreme Gradient Boosting to Predict Atomic Layer Deposition for Platinum Nano-Film Coating.

Extreme gradient boosting (XGBoost) is an artificial intelligence algorithm capable of high accuracy and low inference time. The current study applies this XGBoost to the production of platinum nano-film coating through atomic layer deposition (ALD). In order to generate a database for model development, platinum is coated on α-Al2O3 using a rotary-type ALD equipment. The process is controlled by four parameters: process temperature, stop valve time, precursor pulse time, and reactant pulse time. A total of 625 samples according to different process conditions are obtained. The ALD coating index is used as the Al/Pt component ratio through ICP-AES analysis during postprocessing. The four process parameters serve as the input data and produces the Al/Pt component ratio as the output data. The postprocessed data set is randomly divided into 500 training samples and 125 test samples. XGBoost demonstrates 99.9% accuracy and a coefficient of determination of 0.99. The inference time is lower than that of random forest regression, in addition to a higher prediction safety than that of the light gradient boosting machine.

Preparation and characterization of Cu with anthracene-2,3,6,7-tetramine as novel recyclable metal-organic frameworks for the Pechmann reactions to prepare coumarin derivatives under solvent-free conditions

Cu with anthracene-2,3,6,7-tetramine ([CuAnTA·2H2O]n) as a recyclable metal-organic framework (MOF) was prepared and used for Pechmann reactions between different substituted phenols and ethyl acetoacetate to obtain coumarin derivatives in good to excellent yields. The prepared catalyst was characterized with various techniques such as FT-IR, XRD, SEM, EDX, BET, BJH and ICP-AES analysis. [CuAnTA·2H2O]n demonstrated good to excellent catalytic efficiency for Pechmann reactions in comparison with to other catalysts. Also, the catalyst is recovered by a simple filtration and reserved its activity even after several cycles.

Preparation and characterization of a Cu complex based on 5-aminoisophthalic acid as a recyclable metal-organic framework for C-S cross coupling

A new heterogeneous and recyclable catalyst was designed by immobilizing Cu based on 5-aminoisophthalic acid ([CuAIPA·2H2O]n) as a metal-organic framework (MOF). This catalyst used for the synthesis of diphenyl sulfide derivatives by C-S cross coupling reaction between thiophenols and various iodobenzenes in DMF solvent. The prepared catalyst was characterized with analytical techniques such as FT-IR, XRD, SEM, EDX, BET and ICP-AES analysis. [CuAIPA·2H2O]n MOF catalyst displayed good to excellent yields for catalytic C-S cross coupling reactions in comparison to other catalysts. The recoverability and reusability related to this catalyst were checked by a simple filtration and retaining its activity after several cycles.

Green synthesis of Cu/Fe3O4 nanoparticles using green tea extract: Evaluation of its catalytic activity, antioxidant and anti-colon cancer effects

• Green synthesis of Cu/Fe 3 O 4 nanoparticles using green tea extract. • Green tea extract was used as a green reducing agent and an excellent stabilizer. • Fe 3 O 4 @ G.tea /Cu nanocomposite have a suitable anticancer activity against colon cell lines. • Fe 3 O 4 @ G.tea /Cu nanocomposite have good antioxidant activity. A sustainable biogenic synthesis for the preparation of green tea plant extract engineered novel magnetic nanocomposite (Fe 3 O 4 @ G.tea ) has been represented in this research. The biocompatible composite was then fabricated with in situ prepared Cu NPs using the green tea derived biomolecules avoiding any harsh chemicals, thus making the procedure absolutely green. The electron rich phytochemicals were additionally used to stabilize the adorned NPs from aggregation or aerial oxidation. Physicochemical features of the ensuing Fe 3 O 4 @ G.tea /Cu nanomaterial was ascertained over a range of instrumental methods, viz., FT-IR, SEM, EDX, elemental mapping, TEM, VSM, XRD, and ICP-AES analysis. Catalytic properties of the bio-nanomaterial were assessed by the synthesis of diverse pyrano[3,2- c ]chromene moieties following a multicomponent reaction (MCR) under eco-friendly conditions. Diverse aromatic and heteroaromatic aldehydes were used in the reaction to afford the products in excellent yields. Reusability of the nanocatalyst was demonstrated by easy magnetic decantation from the reaction medium and subsequent recycling for 8 consecutive runs without considerable loss in its activity. Furthermore, the Fe 3 O 4 @ G.tea /Cu bio-nanomaterial was employed in the biological evaluation against reducing the proliferation of human colorectal cancer and investigating the cytotoxicity against two colorectal cell lines, HT-29 and Caco-2 respectively following MTT assay. The studies documented an increase in % cell viability with increase in material concentration and the corresponding IC 50 values obtained as 384.2 μg/ml and 254.6 μg/ml respectively. Again, anti-oxidant activity of the material was determined by DPPH radical scavenging analysis.

Innovative In Vitro Strategy for Assessing Aluminum Bioavailability in Oral Care Cosmetics.

Aluminum is an element found in nature and in cosmetic products. It can interfere with the metabolism of other cations, thus inducing gastrointestinal disorder. In cosmetics, aluminum is used in antiperspirants, lipsticks, and toothpastes. The aim of this work is to investigate aluminum bioavailability after accidental oral ingestion derived from the use of a toothpaste containing a greater amount of aluminum hydroxide than advised by the Scientific Committee on Consumer Safety (SCCS). To simulate in vitro toothpaste accidental ingestion, the INFOGEST model was employed, and the amount of aluminum was measured through the ICP-AES analysis. Tissue barrier integrity was analyzed by measuring transepithelial electric resistance, and the tissue architecture was checked through light microscopy. The margin of safety was also calculated. Overall, our results indicate that the acute exposure to aluminum accidentally ingested from toothpastes is safe for the final user, even in amounts higher than SCCS indications.

Landfill gas as a source of anthropogenic antimony and arsenic release

Antimony is used extensively in consumer goods, including single use plastic bottles, electronics, textiles and automobile brakes, which are disposed of in landfills at the end of their service lives. As a result, Sb is a constituent of concern in landfill emissions. Previous research has focused on leachate (liquid) and waste incineration flue gas emissions; however, Sb has the potential to volatilize through chemical and microbial processes within a landfill. In this study, iron-amended granular activated carbon was used to adsorb volatile metals directly from gas in a full-scale landfill gas collection system. Metals were quantified using acid digestion and ICP-AES analysis. Antimony concentrations far exceeded those previously reported, at up to 733 μg m−3 (mean: 254 μg m−3). In addition to Sb, As was also measured at high levels compared to previous research, as high as 740 μg m−3 (mean: 178 μg m−3). Using US EPA landfill and landfill gas databases, total Sb emissions via landfill gas are estimated to be approximately 27.3 kg day−1 in the US. Based on other estimates of national and global Sb emissions, this corresponds to approximately 4.5% of total US atmospheric emissions of Sb and 0.42% of global atmospheric emissions. Sb mass release via landfill gas is approximately 3.9 times higher than via leachate emissions. Although gas emissions are higher than expected, the vast majority (99.9%) of Sb present in landfilled MSW remains within the waste mass indefinitely. In addition to these mass release estimates, this experiment suggests that iron-amended activated carbon may offer significant metals removal from LFG, especially in the first months of new well operation.

Intermediate moisture kinnow bar from low grade kinnow mandarins: Phytonutritional profile, morphological characterization, and storage stability

Low grade kinnow have less commercial value but are rich in bioactive compounds and have enough potential for value addition. The present study aimed at utilizing kinnow juice extracted from low-quality kinnow to develop a convenient ready-to-eat phytonutrients-rich fruit bar. Pectin was added at different concentrations (1–4%) to improve the quality of the formulated bar. Increasing the pectin levels increased the hardness of formulated bars while decreasing moisture and water activity, without affecting color and nutritional properties. Developed bars showed high minerals and phytochemical constituents (8.41 mg/100 g ascorbic acid, 591.48 mg GAE/100 g total phenolic, 388.56 mg QE/100 g total flavonoids, 3.28 mg/100 g total carotenoids, 20 ppm limonin, and 68.12% antioxidant activity) as confirmed using colorimetric and ICP-AES analysis. The microstructure of the bars was consistent with the texture values. Based on desirable sensory and textural properties, kinnow bars formulated with 4% pectin was selected for product development and evaluation of shelf life under room (25 ± 2 °C) and refrigerated (4 ± 2 °C) conditions. A significant (p < 0.05) difference was observed in physicochemical, phytochemical, and microbiological attributes during storage at both temperatures. However, the loss of quality was rapid at room temperature. Kinnow bars were shelf-stable for up to 4 months at room temperature and 6 months under refrigeration conditions, respectively. Valorization of low grade kinnow can provide the dual benefit of producing phytonutrient-rich snack product along with kinnow waste management.

Strecker synthesis of α-aminonitriles using Au nanoparticles‏¬‏ capped with porous SiO2 shell (Au@pSiO2) as a highly efficient and recyclable nanostructured catalyst

Nano Au@porous SiO2 as a heterogeneous catalyst characterized by UV-Vis, XRD, TEM, and ICP-AES analysis. Amount of Au in Au@pSiO2 showed the 3.85% wt of Au in Au@porous SiO2 and the peak at 523 nm in UV-Vis spectrum dedicated to Au NPs. The prepared catalyst used in the condensations of various aldehydes and amines with smooth nucleophilic addition with trimethylsilyl cyanide through the one-pot three-component Strecker reaction for the preparation of α-aminonitrile derivatives in good to excellent yields at room temperature under solvent free reaction conditions. Short reaction periods, rapid access to products, ease of catalyst separation and simple workup, high chemical and thermal stability and reducing the leaching of the nanocatalyst into the environment are the important advantages of this nanocatalyst.

Microscopic Structure and Binding Mechanism of the Corrosion-Protective Film of Oleylpropanediamine on Copper in Hot Water

The structure of the film formed by oleylpropanediamine (OLDA) on the copper (Cu) metal surface in water at 150 °C was investigated by combining quantitative NMR and surface characterization methods. We succeeded in quantifying the amount of film formation by precisely determining all mass balances in the systems examined. 2D IR microscopic mapping showed that the film thickness is uneven in the horizontal direction with a length scale of ∼100 μm and hundreds of OLDA layers. This film thickness was also confirmed by AFM. The analysis of the C–H stretching vibrational frequency disclosed that the alkyl chains are highly ordered in the layers close to the Cu surface and are conformationally disordered in the layers distant from the Cu surface in the thicker portion of the film. Combining XPS measurements using argon gas cluster ion beam etching with the ICP-AES analysis, we revealed that the key to multiple layering is the formation of a coordination complex of the unprotonated amino groups of OLDA with Cu that presumably results in polymer chain-like network structures. Contact angle measurements at different OLDA concentrations and treatment times showed that the water repellency of the film originated from the thick layering of OLDA molecules with disordered hydrophobic chains.