Ferric Chloride Solution Research Articles

Nanoflower-like NiCoFe layered hydroxide by in-situ electrochemical corrosion as highly efficient electrocatalyst for water oxidation

Layered double hydroxides have been widely applied for oxygen evolution reaction (OER) in the alkaline water electrolysis. However, the issues of poor connection between the catalyst and nickel foam and the specific mechanisms for active sites has not been fully documented. In this study, the in-situ nickel foam etching in a mixed solution of ferric chloride and cobalt nitrate at low temperatures was adopted for NiCoFe layered ternary hydroxides (NiCoFe LTHs) synthesis with a better tight integration. Physicochemical characterization indicated that the NiCoFe LTHs could grow directly through corroding nickel foam with a nano-flower-like morphology and structures. That is favorable for electron transfer from the catalytic layer to the conductive substrate. With the transition metal ions interaction and the tight integration construction, NiCo1Fe4-LTH-T60/NF presented an enhanced electrolysis performance with the overpotential of 234 mV (1.464 V vs. RHE) at current density of 100 mA cm−2 in 1 M KOH electrolyte. The Tafel slope for NiCo1Fe4-LTH-T60/NF electrode was 36.19 mV dec−1 for an enhanced OER kinetics. Besides, it demonstrated faster interfacial charge transfer process, better intrinsic electrochemical activity and stability in large current stability testing. It was revealed that the synergistic effect of the transition metal ions interaction enhancement and the mechanism of oxygen evolution elementary reaction for NiCo1Fe4-LTH-T60/NF during the water electrolysis by the electrochemical and theoretical calculation. This work provides theoretical basis and experimental support for the design and synthesis of future OER catalyst and substrate, which is significant for hydrogen and oxygen generation from water electrolysis.

Lithium extraction from a clay-type lithium ore using a mixed solution of sulfuric acid and ferric chloride

The demand for lithium resources continues to grow owing to the extensive application of lithium-ion batteries in the clean energy industry, and in consequence the development of lithium extraction technologies is significant. In this study, the mixed solution of H2SO4 and FeCl3 was found to have a synergistic effect on the lithium extraction from a clay lithium ore. Upon calcination at 600 °C for 60 min, followed by leaching with a mixture of 10.5 w% H2SO4 and 2 w% FeCl3 at a liquid-to-solid ratio of 5 mL/g for 90 min at 80 °C, a lithium leaching efficiency of 96.18 % was obtained, better than using individual H2SO4 and FeCl3 at higher concentrations. The TG-DTG-DSC, FTIR, BET and XRD results showed that with the increase of calcination temperature the structures of partial minerals such as kaolinite and cookeite became collapsed, amorphous, unstable and activated, which favored for the release of lithium. With the further increase of calcination temperature, the mineral structure continued to collapse and tends to be stable, making the interlayer lithium tightly fixed and difficult to be released. The XRD and SEM results indicated that the lithium extraction is an ion exchange process rather than mineral dissolution. The synergistic effect of H2SO4 and FeCl3 on the lithium extraction was attributed to the fact that the entry of Fe3+ into the interlayer of the layered structure of clay minerals not only released Li+, but also increased the interlayer spacing, conducive to the access of H+ to the interlayer, and consequently facilitated the ion exchange of H+ and Li+.

Green Synthesis of Iron Nanoparticles (FeNPs) using Aqueous Extract of Murraya koenigii Leaves: Synthesis Mechanism, Characterization Process and Antibacterial Activity

Introduction: Green synthesis is the method of producing metal and metal oxide nanoparticles from the extraction of plant materials. This study aims to synthesize iron nanoparticles (FeNPs) using an aqueous extract of Murraya koenigii leaves as an eco-friendly approach and subsequently characterize the synthesized FeNPs to understand their structural, morphological, compositional and optical properties. Methods: The aqueous extract of Murraya koenigii leaves and 0.1M ferric chloride solution were combined at room temperature in a 1:2 volume ratio. The synthesized FeNPs were characterized using analysis methods of Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), UV-visible (UV-vis) and Tacu plot. Results: SEM images discovered that the particles were in the nanoscale range and their morphology appeared spherical shape. The EDX study was used to identify the composition of the elements of synthesized FeNPs. The crystal structure of the synthesised FeNPs was shown in the XRD spectrum. The FTIR spectrum showed many distinctive bands and the bands revealed active components for functional groups in the synthesized FeNPs. The UV-vis spectrum revealed an absorbance peak range of 240-310 nm for FeNP formation with a maximal peak at 273 nm. The band gap energy of the synthesized FeNPs was found to be 2.07 eV using the Tauc plot method. Also, the synthesized FeNPs exhibited a significant antibacterial effect against bacterial pathogens. Conclusion: The results of the characterization methods strongly suggest that the aqueous leaf extract of Murraya koenigii can be used as a reducing and stabilizing agent in the green synthesis of FeNPs.

Withdrawal: Conductive Hydrogel Dressing With High Mechanical Strength for Joint Wound Healing.

Hydrogel wound dressing can accelerate angiogenesis to achieve rapid wound healing, but traditional hydrogel dressings are difficult to meet the repair of joint sites due to their low mechanical strength. Therefore, we constructed the gel system by designing the chemical-physical interpenetrating network structure to achieve high strength and high toughness of the hydrogel. The high-strength double-network hydrogels were synthesized by simple free radical polymerization and low-temperature physicochemical cross-linking in our experiments. The suspension was obtained by green reduction of graphene oxide with carboxymethyl chitosan, followed by the introduction of acrylamide (AM) to form a covalent cross-linked network, which was immersed in ferric chloride solution to form metal ligand bonds, and finally the chemical-physical dual cross-linked network hydrogel wound dressing was prepared. Here, reduced graphene oxide can enhance electrical conductivity and excellent near-infrared photothermal effect to the hydrogel. The cell viability of this novel wound dressing was above 90.0%, its hemolysis rate was below 2.0%, and the electrical conductivity could reach (6.89 ± 0.07 (mS/cm)). In addition, the stress-strain curve demonstrated that the double cross-linked network hydrogel could reach a stress of more than 0.8MPa at 82.0% strain, and the cyclic compression experiment shows that it can still recover its original shape after five times of repeated compression. This work can provide a reference for the exploitation of high mechanical strength hydrogel wound dressings with good electrical conductivity and near-infrared photothermal effect. This article is protected by copyright. All rights reserved.

Laser ablation and chemical vapor deposition to prepare a nanostructured PPy layer on the Ti surface

Abstract The deposition of polypyrrole (PPy) on a Ti surface is commonly employed to enhance the material’s properties for different applications such as supercapacitors, biomedicine, and corrosion resistance. Instead of complex or costly polymerization procedures for the PPy synthesis on the Ti metal surface, we utilized the effect of a simple and inexpensive laser ablation of the Ti surface in the open-air environment to prepare a hydrophilic TiO2 surface. In this condition, a thin PPy layer with remarkable nanostructures such as nanorings (∼80 nm) and nanotubes (∼245 nm) was deposited on a selective and desired pattern of ablated Ti areas through the chemical vapor deposition process using ferric chloride (FeCl3) solution as a pyrrole oxidizer. Raman and X-ray photoelectron spectroscopy (XPS) analyses confirmed the PPy formation on the Ti surface. The creation of these nanostructures was due to the micro/nanomorphology of the ablated Ti substrate. Water contact angle (WCA) measurements indicated the hydrophobic behavior of the PPy/Ti surface by the aging effect after 24 weeks with the change of WCA from 20° to 116°. The change in the surface chemical composition upon adsorption of airborne organic compounds with the long-term storage of PPy/Ti surface in air was studied by the XPS test.

Optimizing hematite filter cake treatment using reducing agents

In drilling operations, the formation of a filter cake is crucial for well stability, but its removal post-drilling is essential to restore rock formation productivity. This study focuses on hematite-based filter cakes and investigates factors influencing their solubility and removal, addressing a significant knowledge gap in the field. The research methodology involves examining the effects of various factors, including types and concentrations of reducing agents, temperature, particle size, and treatment duration, on the dissolution process. Notably, Nuclear Magnetic Resonance (NMR) tests are employed to assess the treatment's impact on core porosity. Among the diverse reducing agents examined, ferrous chloride emerges as the optimal choice for effectively enhancing hematite solubility. Particularly, a composite solution of ferrous chloride (10 wt.%) and hydrochloric acid (6 wt.%), was highly efficient demonstrated by exhibiting rapid solubilization of hematite filter cakes. A removal efficiency of approximately 99%, with a parallel enhancement in core permeability was achieved. NMR tests reveal the treatment's success in reinstating the porosity system, which had undergone reduction due to drilling fluid particles. Crucially, the solution exhibits a considerably lower corrosion rate than concentrated hydrochloric acid, highlighting its potential to mitigate environmental concerns while ensuring efficient filter cake removal. The findings of this research provide valuable insights into optimizing post-drilling operations, balancing environmental sustainability and operational efficiency. The identified composite solution offers a promising approach to efficient filter cake removal while mitigating environmental concerns associated with corrosion. Overall, this study contributes to advancing the understanding and practice of well productivity enhancement in the oil and gas industry.

Fabrication of iron nanoparticles using different bioactive precursors, their characterization and bioactivity evaluation

This study deals with the green synthesis of Iron nanoparticles (FeNPs) using plant extracts of Polygonum plebeium (Knotweed) and Camellia sinensis (Green tea), focusing on their antibacterial potential, biocatalytic action as well as prospective applications as nanofertilizers. Plant materials underwent a thorough cleaning and were processed into aqueous extracts. The synthesis of FeNPs involved blending these extracts with ferric chloride solution, resulting in a versatile nanomaterial that was subjected to various characterization techniques, such as UV-Vis spectroscopy, FT-IR, XRD, SEM, and DLS-Zeta unveiling critical nanoparticle attributes of the synthesized nanoparticles, including the size, crystallinity, morphology, stability, and elemental composition. The synthesized FeNPs exhibited substantial antibacterial activities, against Escherichia coli and Staphylococcus aureus. Additionally, the biocatalytic properties of the synthesized FeNPs were investigated through dye degradation. These nanoparticles further, were demonstrated for their potential as nanofertilizers, enhancing the germination and growth of tomato and radish seeds. The merging of nanotechnology and plant-based synthesis represents a promising intersection with the capacity to revolutionize diverse fields.

Laboratory study of a kaolinitic soil and sodium hydroxide interaction mechanisms and resulting swelling stresses

The study of prolonged exposure of natural soils to alkaline solutions has been conducted to analyze and control the local soil swelling behavior observed in industrial sites. The occurrence of foundation heave in a Brazilian industrial site prompted a laboratory investigation aimed at understanding the mechanism of interaction between soil and alkali that induced swelling behavior. The study was extended to determine the corresponding swelling stress to be used in reinforcement design, and to investigate the soil response to chemical stabilization with 5% ferric chloride solution. Previously, a comprehensive mineralogical and physical-chemical investigation was accomplished using industrial caustic liquor and four natural soils from local stratigraphy. All soils are mainly constituted by kaolinite and quartz, and one also presents some montmorillonite. Both kaolinite and montmorillonite were degraded by NaOH liquor, and newly formed minerals were identified. The expansion is related to the mechanism of the silica-NaOH reaction. In the study reported here, the local soil with the highest volume change in sedimentation tests with NaOH solutions was subjected to quasi-constant volume oedometer tests with water and with 4N NaOH solution to determine the swelling stresses resulting from the reactions until stabilization. The alternative of chemical treatment with 5% ferric chloride solution was investigated through the same testing procedure. X-Ray diffraction analyses were applied to evaluate the changes in mineralogy. The swelling vertical stress reached 40 kPa under confined conditions, and stabilization took up to 40 days. The chemical treatment was effective in controlling ongoing reactions, but not effective in prevention.

Quantitative Estimation of Secondary Metabolites of Shadanga Paniya Classical Ayurvedic Formulation and Constituent Herbs

Abstract Background: In the present scenario, ayurvedic drugs and their formulations need standardization to understand their pharmacokinetics and to prevent any safety issues. Shadanga Paniya (SP) is a classical ayurvedic formulation composed of six herbs and most of the constituent herbs have been shown the presence of alkaloids, flavonoids, and total phenolic contents (TPC). Materials and Methods: Preliminary qualitative estimations of alkaloids, flavonoids, and TPC in SP formulation and its constituent herbs were done using Dragendroff’s method, sodium hydroxide solution, and ferric chloride solution. The quantitative estimations were done using bromocresol green, aluminum chloride colorimetric method, and Folin–Ciocalteu’s phenol reagent method. Statistical Analysis Used: All the qualitative and quantitative analyses were replicated in three independent assays, and the results were reported as a mean ± standard deviation. Results and Conclusion: The results revealed that constituent herbs of SP formulation have the presence of flavonoids and total phenolic acid, whereas alkaloid was only found in Vetiveria zizanioides herb. The quantitative estimation of alkaloids, total flavonoids, and total phenolic acid contents of SP formulation was found as 86.105 ± 6.4 mgAE/g, 87.8 ± 4.0 mgRE/g, and 105.8 ± 3.8 mgGAE/g, respectively. This is the first report on the phytochemical estimation of SP formulation.

A sustainable method for lithium recovery from waste liquids: Thermodynamic analysis and application

In this study, lithium was efficiently enriched and recovered from low concentration waste liquids by sodium phosphate precipitation and wet conversion. Firstly, the efficient extraction of lithium at low concentration was realized based on the lower solubility of lithium phosphate. The factors involved in the lithium phosphate precipitation process by sodium phosphate were systematically investigated, and it was discovered that the high temperature process promoted the formation of lithium phosphate, with the lithium precipitation rate reached 94.32% under optimal conditions. The feasibility of the conversion of lithium phosphate into lithium chloride solution and iron phosphate by ferric chloride solution was analyzed by thermodynamic study. The experimental results also further confirmed that the lithium conversion rate was as high as 96.06% when the reaction temperature was 25 °C and the pH of the system was 2. The conversion process achieved the enrichment of lithium from low to high concentrations, avoiding the high energy consumption caused by conventional evaporation and concentration. More importantly, the alkaline leaching of the converted residue realized the separation of phosphorus and iron sources, and then the re-synthesis of ferric chloride solution and sodium phosphate reagent was accomplished by acid leaching and crystallization, respectively, allowing for reagent recycling in the lithium extraction process. The proposed process is expected to provide a green and sustainable route for the recovery of low concentration lithium from waste liquids.

Anti-freezing, tough, and stretchable ionic conductive hydrogel with multi-crosslinked double-network for a flexible strain sensor

Ionic conductive hydrogels are an ideal material for use in flexible strain sensors due to their electrical conductivity, accurate data retrieval, and extensibility. However, conventional ionic conductive hydrogels including salt/organics or salt-based hydrogels with high ionic content exhibit modest antifreeze and limited mechanical properties, hampering their practical use across diverse sectors. The preparation process is tedious due to the incorporation of toxic photoinitiator and chemical crosslinking agents. Herein, through a simple, low-cost, and environmentally friendly strategy, we have developed a multi-crosslinked double network ionic conductive hydrogel by using polyvinyl alcohol bearing styrylpyridinium groups (PVA-SbQ) and sodium alginate (SA) via UV irradiation, followed by immersion in a mixed solution of ferric chloride (FeCl3) and glycerol (Gly)/water. This synergistic effect of FeCl3 and Gly has endowed the PVA-SbQ/SA/FeCl3/Gly hydrogel with exceptional mechanical properties (tensile strength of 2.48 ± 0.45 MPa and elongation at break of 1452 ± 101 %), anti-freezing ability (-42.3 °C), and electrical conductivity of 0.38 S/m and 0.32 S/m at room temperature and −30 °C, respectively. Moreover, the hydrogel exhibits remarkable strain sensitivity (GF = 2.49), allowing it to be used as a strain sensor under both room temperature and subzero conditions. Consequently, the prepared hydrogel sensor can monitor various human motions, such as joint bending, running, and speaking. Therefore, our work offers a promising strategy for the preparation of PVA-based hydrogels with outstanding mechanical properties, electrical conductivity, and resistance to freezing, rendering them a practical option for flexible sensors. In addition, our anti-freezing method has significant potential in enhancing the accessibility of ionic conductive hydrogels.

Cognizant Fiber-Reinforced Polymer Composites Incorporating Seamlessly Integrated Sensing and Computing Circuitry.

Structural fiber-reinforced polymer (FRP) composite materials consisting of a polymer matrix reinforced with layers of high-strength fibers are used in numerous applications, including but not limited to spacecraft, vehicles, buildings, and bridges. Researchers in the past few decades have suggested the necessary integration of sensors (e.g., fiber optic sensors) in polymer composites to enable health monitoring of composites' performance over their service lives. This work introduces an innovative cognizant composite that can self-sense, compute, and implement decisions based on sensed values. It is a critical step towards smart, resilient infrastructure. We describe a method to fabricate textile sensors with flexible circuitry and a microcontroller within the polymer composite, enabling computational operations to take place in the composite without impacting its integrity. A microstructural investigation of the sensors showed that the amount of oxidative agent and soaking time of the fabric play a major role in the adsorption of polypyrrole (PPy) on fiberglass (FG). XPS results showed that the 10 g ferric chloride solution with 6 h of soaking time had the highest degree of protonation (28%) and, therefore, higher adsorption of PPy on FG. A strain range of 30% was achieved by examining different circuitry and sensor designs for their resistance and strain resolution under mechanical loading. A microcontroller was added to the circuit and then embedded within a composite material. This composite system was tested under flexural loading to demonstrate its self-sensing, computing, and actuation capabilities. The resulting cognizant composite demonstrated the ability to read resistance values and measure strain using the embedded microcontroller and autonomously actuate an LED light when the strain exceeds a predefined limit of 2000 µε. The application of the proposed FRP system would provide in situ monitoring of structural composite components with autonomous response capabilities, as well as reduce manufacturing, production, and maintenance costs.

A Microfluidic Paper-based Analytical Device for Simultaneous Measurement of Albumin, Creatinine and Uric Acid in Urine based on Standard Addition Method

This work describes a simple method for the simultaneous measurement of urinary albumin, creatinine and uric acid using a standard addition approach on a microfluidic paper-based analytical device (µPAD). Hydrophobic barrier of the µPAD was created by stamping indelible ink onto a filter paper. The µPAD was designed with a flower-liked configuration. After aliquoting urine to a central sample zone, the sample flowed to ten surrounding channels, namely “the inner channels”, where the blank (water) or standard solutions had been added. The inner channels were connected to circular reagent zones where reagents had been immobilized. Tetrabromophenolphthalein ethyl ester, alkaline picrate, and a mixed solution of ferric chloride and ferric cyanide were used as the chromogenic reagents for the colorimetric detections of albumin, creatinine, and uric acid, respectively. Each reagent zone was linked with a circular detection zone through a second channel, namely “the outer channels”. The blue-, orange- and greenish-blue colored products were observed in the detection zones for the measurement of albumin, creatinine, and uric acid, correspondingly. A digital image of the µPAD was captured with a mobile phone. The color intensities were evaluated by ImageJTM and were employed for the quantitative analyses. The standard addition calibrations were found to be linear (r2 > 0.99) for the spiked analyte concentrations up to 100 mg L-1 albumin, 1000 mg L-1 creatinine, and 50 mg dL-1 uric acid. The paper platform provided high precision (RSD < 5 %) and good analytical recovery (91.8-109.7 %). Under paired t-test, the results obtained by the developed µPAD and the validating methods were not significantly different at 95 % confidence (albumin: tstat = -0.130, tcri = 3.182, creatinine: tstat = -0.133, tcri = 3.182, and uric acid: tstat = 1.119, tcri = 3.182).

PCB (Printed Circuit Board) Etching Machine Using ESP32-Camera Based Internet Of Things

Today's technology is automated. In car alarm devices, to automatic parking. This very rapid development of technology makes humans create equipment that can make it easier for humans. The etching process can also be called the Printed Circuit Board screen printing process, which is the creation of a path or layout that will connect between electrical components. PCB etching machine is a tool used to dissolve metal parts that are not designed on plain PCB boards using a mixture of chemical solutions, namely ferric chloride. Manual PCB processes usually take a long time and risk being exposed to ferrit chloride solutions for users. This article discusses how to make an automatic etching machine tool with a Microcontroller module that has a camera feature to monitor the editing results on a copper board. With the time method as the key to perfect results during the checking process. For as a driver, that is using a Servo Motor. The microcontroller used in this machine is an ESP32 camera based on the Internet of things Telegram as a Data Base media. For software design using fritzing software applications. The success of the PCB etching machine in this study is seen from testing tools ranging from voltage testing, microcontroller testing, real time a clock testing and Internet of Things system testing. From many of these tests, good results were obtained.

Effect of Polymerization Variables on the Electrical Conductivity of Polyaniline Functionalized Cotton Textiles

Polyaniline functionalized cotton textiles were synthesized via in situ oxidative polymerization of aniline using hydrated ferric chloride solution in acidic media. Variation in conductivity was examined against polymerization variables such as amount of aniline, oxidant, reaction media, and time. Effects of polyaniline functionalization on the structural features of cotton textiles at optimum polymerization conditions were screened by FT-IR, TGA, and SEM instruments. FT-IR profiles at 1440 cm-1 and 1560 cm-1 proved the existence of benzoid and quinoid rings within the cotton structure, which confirmed the introduction of polyaniline in its conductive form, emeraldine salt. Thermal studies revealed the existence of polyaniline, which further enhanced the thermal stability of cotton textiles. SEM microstructure also proved the formation of nonuniform surfaces with a considerable amount of debris, buds, and channels due to the inclusion of polyaniline. Polyaniline functionalization has shown substantial enhancement of electrical conductivity by changing insulating cotton to semiconductor. At optimum polymerization variables ([aniline] = 1 M, [oxidant] = 1 M, [acid] = 0.5 M, and time = 24 hrs), maximum conductivity was registered at 7.63 X 10-3 S/cm, which is equivalent to the conductivity of semiconductor materials.

Resilient and Tough Conductive Polymer Hydrogel for a Low-Hysteresis Strain Sensor.

Conductive polymer hydrogels are vital in strain sensors, yet achieving high resilience and toughness is a challenge. This study employs a prestretch method to engineer a tough conductive polymer hydrogel with sufficient resilience. Initially, a blend film of polyvinylalcohol (PVA) and ethylene-vinyl alcohol copolymer (EVOH) is prepared through solution casting, followed by a swelling process to form a PVA-EVOH hydrogel. This hydrogel, with PVA crystallites as crosslinking points, exhibits high toughness. The hydrogel is then immersed in pyrrole and ferric chloride solutions for in-situ polymerization of polypyrrole (PPy), creating a conductive PPy/PVA-EVOH hydrogel. Finally, a 200% prestretch is applied, breaking short chains within the network, eliminating energy dissipation at low strains. This results in a hydrogel with a 100% elastic deformation range, while maintaining high fracture toughness (1700Jm-2 ). The prestretched PPy/PVA-EVOH hydrogel functions as a strain sensor with low hysteresis, providing consistent strain measurements during loading and unloading. This outperforms the non-prestretched sample, which shows inconsistent responses between stretching and releasing.

Adsorption of Chromium, Copper, Lead, Selenium, and Zinc ions into ecofriendly synthesized magnetic iron nanoparticles.

The iron nanoparticles (Fe-NPs) have been synthesized using an environmentally friendly and simple green synthesis method. This study aims to obtain an aqueous extract from natural material wastes for synthesizing Fe-NPs. The produced Fe-NPs were evaluated as adsorbents for removing Pb, Se, Cu, Zn, and Cr from aqueous solutions. The formation of Fe-NPs was observed on exposure of the aqueous extract to the ferrous chloride and ferric chloride solutions. The characterization of the synthesized Fe-NPs was carried out using different instrumental techniques. As a function of the initial metal ion concentration, contact time, and various doses, the removal of the heavy metal ions was investigated. The UV-Vis spectrum of Fe-NPs showed a peak at 386 nm, 386 nm, 400 nm, 420 nm, 210 nm, 215 nm, and 272 nm of banana, pomegranate, opuntia, orange, potato, and onion, respectively. The FT-IR spectra confirmed the attachment of bioactive molecules from plants on the Fe-NPs surface. The effective reduction of metal ions was greatly aided by the -OH functional groups. The functional groups were examined and responsible for adsorption process by nanoparticle powder sample, these peaks are 3400 cm-1, 2900 cm-1, 1600 cm-1,1000 cm-1, and 1550 cm-1. The magnetization measurements revealed superparamagnetic behavior in the produced iron oxide nanoparticles. Heavy metal ions uptake followed a time, dose, and initial concentration-dependent profile, with maximum removal efficiency at 45 min, 0.4 g, and 3.0 mg/L of metal concentration, respectively.

Enhancing pitting corrosion inhibition of AISI 304 stainless steel using a green frankincense-modified ferric chloride solution

Abstract To inhibit pitting corrosion of AISI 304 stainless steel (SS), the effect of different percentages of frankincense addition to a 0.5 M ferric chloride solution was explored in this work for the first time. The samples were investigated for pitting corrosion susceptibility via electrochemical noise (EN) tests, where the current and potential noises were recorded for 10000 seconds, and potentiodynamic polarization. The frequency domain of EN data was analyzed using power spectral density (PSD). Frankincense addition to the ferric chloride solution effectively reduced the pitting corrosion of AISI 304 SS. The pitting inhibition was concluded from the high fluctuations in current noises over the test period, its decreasing amplitude, the greater positive potential, the lower current values, and the lower spectral noise and noise resistances with increasing frankincense additions. Optical microscope images supported pitting inhibition with frankincense addition, where pits decreased in number per mm2 and size. A significant decrease in the pit size and pits mm−2 was observed with the 10 wt.% frankincense addition. It was attributed to the adsorption of the inhibitor on the stainless steel surface, inhibiting the adsorption of chloride ions. Additionally, frankincense addition reduced the corrosion current and increased the corrosion potential positively.

Role of mass effect on neuronal iron deposition after intracerebral hemorrhage

Mass effect after intracerebral hemorrhage (ICH) not only mechanically induces the brain damage, but also influences the progress of secondary brain damage. However, the influence of mass effect on the iron overload after ICH is still unclear. Here, a fixed volume of ferrous chloride solution and different volumes of poly(N-isopropylacrylamide) (PNIPAM) hydrogel were co-injected into the right basal ganglia of rats to establish the ICH model with certain degree of iron deposition but different degrees of mass effect. We found that mass effect significantly increased the iron deposition on neuronal cells at 6 h after ICH in a volume-dependent manner. Furthermore, the upregulation of Piezo-2, divalent metal transporter 1 (DMT1), transferrin receptor (TfR), and ferroptosis expressions were noted as the increase of mass effect. In addition, the pERK1/2 inhibitor PD98059 treated ICH rats reversed the upregulation of iron uptake protein and ferroptosis. Our findings revealed the relationship between mass effect and the iron uptake and ferroptosis, which are benefit to understand the brain damage process after ICH.

A novel recycling route for aluminum alloys: Synthesis of Fe/Al bimetallic materials and magnetic separation

Aluminum (Al) is one of the most important non-ferrous metals used in modern society, but its production from primary ores (e.g., bauxite) requires high energy input, emits large CO2, and generates huge amounts of solid wastes. In contrast, the production of Al from recycled scrap—also known as secondary Al production—only requires 5–8% of the energy for producing Al from bauxite and generates less amount of solid waste than that of the primary Al production, thus having both economic and environmental benefits. In general, scrap Al alloys are treated by physical-based separation techniques to remove impurities, and then mixed aluminum alloys are charged into the furnace for further refining. The ideal way of recycling Al scrap is to process each Al alloy by remelting/refining processes. To this end, this study investigated the surface modification of aluminum alloys by iron (Fe) deposition, followed by their separation by magnetic separation.When Al powder was treated with an acidified ferrous chloride solution (FeCl2-HCl-NaCl solution), dissolved Fe concentration decreased with time while releasing Al3+ into the solution, indicating that Fe cementation on Al occurred. X-ray photoelectron spectroscopy (XPS) analysis of treated Al powder showed that its surface was covered with zero-valent iron (ZVI) as well as its oxidation products (e.g., Fe(II)/Fe(III)-oxyhydroxide). The synthesis of Fe/Al bimetallic materials from Al alloys—1050, 2024, 3003, 5083, 6061, and 7075—was strongly dependent on HCl concentration as well as reaction temperature. Moreover, the kinetics of Fe cementation on Al alloys and the amounts of Fe cemented were determined not only by the rest potentials of the Al alloys but also their corrosion resistance. After treating Al alloys with FeCl2-HCl-NaCl solution, each Al alloy could be sequentially recovered by magnetic separation.