FeCl3 Concentration Research Articles

Effect of Curing Time and Ferric Chloride on a Copper Concentrate with a High Arsenic Content

As a result of changes in copper mineralogy, various treatment options for copper sulfides have been explored, including pretreatment processes aimed at enhancing material permeability and improving the dissolution of valuable minerals. Despite its significance, this topic has only recently gained attention. In this research, a copper concentrate with a high arsenic content was studied, with enargite (Cu3AsS4) as the main mineral phase. The objective was to evaluate the effect of pretreatment on copper extraction efficiency prior to leaching. Three key variables were investigated: curing time (0, 5, 10, and 15 days), H2SO4 dosage (0, 70, 140, and 210 kg/t), and FeCl3 concentration (0, 0.5, 1, and 1.5 M). The sample was characterized both before and after pretreatment, revealing the formation of new species such as CuSO4·5H2O and Cu2Cl(OH)3 under optimal conditions of 15 days curing time, 70 kg/t of H2SO4, and 1 M FeCl3. Copper extraction solely through curing reached 20.79%. The analysis suggests that curing time is the most influential factor in the process, accounting for 46% of the overall contribution. In comparison, sulfuric acid and ferric chloride contribute less, with 20% and 10% contributions, respectively.

Iron-Modified Nano-TiO2: Comprehensive Characterization for Enhanced Photocatalytic Properties

This study investigates the effect of iron-modified nano-TiO2, using the co-precipitation method with different concentrations of FeCl3 (0.1, 1, and 10%), to improve its photocatalytic properties for outdoor applications. To this end, modified and unmodified nano-TiO2 were characterized using different techniques. The optical properties were characterized by diffuse reflectance spectroscopy (DRS) followed by band gap calculation. X-ray diffraction (XRD) was used to analyze the crystalline structure. Chemical and morphological characterization were carried out using energy-dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM). The photocatalytic activity was investigated by decolorizing Rhodamine B aqueous solutions under similar sunlight irradiation. The results indicate that the modification improved light absorption in the UV range for all iron concentrations; however, only the concentration of TiO2: FeCl3 (10%) shifted the absorption to the visible region. Also, including Fe3⁺ in TiO2 decreased the band gap energy from 3.14 to up to 2.80 eV. There were variations in crystallite size from 21.13 to up to 40.07 nm. The nano-TiO2 morphology analysis showed that it did not change after iron modification. EDS showed an FeCl3 peak only at higher concentrations (10%). In addition, the 0.1% Fe-modified TiO2 exhibited the highest activity in the photocatalytic process, with an efficiency of 95.23% after 3 h of irradiation.

Fe3+ augmentation enhancing the nitrogen and phosphorus control in denitrification biofilter based on water supply sludge: Performance and microbial characteristics

The intricate mechanisms of iron (Fe) enhancing the simultaneous nitrogen (N) and phosphorus (P) removal in the denitrification biofilter (DNBF) remain enigmatic and warrant further investigation. Fe2+ and Fe3+ were added to compare the enhancing performances and the dosage concentration was optimized in this study, and the effects of Fe3+ on microbial characteristics were elucidated furtherly. Results demonstrated that the N removal performance with Fe3+ enhancing was better than Fe2+, and the optimal FeCl3 concentration was 0.56 mg/L. The effluent concentrations of total phosphorus (TP), total nitrogen (TN), and chemical oxygen demand (COD) lowed to 0.27, 4.2, and 13.4 mg/L, respectively. Fe3+ promoted microbial richness and diversity, with Proteobacteria, Bacteroidetes and Firmicutes emerging as the advantageous phyla for N and P removal in the DNBF. Microorganisms facilitated Fe3+ reduction to enhance denitrification process, and P was predominantly removed through the precipitation formed by the interaction of Fe and P. Furthermore, Fe3+ was noted to promote functional metabolism, thereby aiding in N removal. This study can reveal the effect of Fe3+ on N removal in the DNBF, and provide a theoretical foundation for advanced N and P removal.

Study on Electrical and Mechanical Properties of Double-End Supported Elastic Substrate Prepared by Wet Etching Process.

Preparing elastic substrates as a carrier for dual-end supported nickel chromium thin film strain sensors is crucial. Wet etching is a vital microfabrication process widely used in producing microelectronic components for various applications. This article combines lithography and wet etching methods to microprocess the external dimensions and rectangular grooves of 304 stainless steel substrates. The single-factor variable method was used to explore the influence mechanism of FeCl3, HCl, HNO3, and temperature on the etching rate, etching factor, and etching surface roughness. The optimal etching parameter combination was summarized: an FeCl3 concentration of 350 g/L, HCl concentration of 150 mL/L, HNO3 concentration of 100 mL/L, and temperature of 40 °C. In addition, by comparing the surface morphology, microstructure, and chemical and mechanical properties of a 304 stainless steel substrate before and after etching treatment, it can be seen that the height difference of the substrate surface before and after etching is between 160 μm and -70 μm, which is basically consistent with the initial design of 0.2 mm. The results of an XPS analysis and Raman spectroscopy analysis both indicate that the surface C content increases after etching, and the corrosion resistance of the surface after etching decreases. The nano-hardness after etching increased by 26.4% compared to before, and the ζ value decreased by 7%. The combined XPS and Raman results indicate that the changes in surface mechanical properties of 304 stainless steel substrates after etching are mainly caused by the formation of micro-nanostructures, grain boundary density, and dislocations after wet etching. Compared with the initial rectangular substrate, the strain of the I-shaped substrate after wet etching increased by 3.5-4 times. The results of this study provide the preliminary process parameters for the wet etching of a 304 stainless steel substrate of a strain measuring force sensor and have certain guiding significance for the realization of simple steps and low cost of 304 stainless steel substrate micro-nano-processing.

Studies of Light Scattering by Hemoglobin Molecules under the Effect of Iron (III) Chloride and Various pH Levels

A lot of literature sources discuss diseases associated with the hemoglobin protein [1, 2]. In the modern world, more than 800 million people suffer from anemia [3]. Assessing the level of hemoglobin in the circulatory system is one of the ways to diagnose anemia. Hemoglobin protein is also a promising source of bioactive peptides [4]. The aim of the work was to identify the reasons leading to conformation changes of this protein. It still remains unclear what exactly causes disruption of its functionality. Human hemoglobin from Sigma H7379 was studied in the work; all experiments were conducted on a dynamic light scattering spectrometer — Photocor Complex. Experimental data were obtained using optical methods of static and dynamic light scattering. The work included an analysis of the behaviour of hemoglobin protein molecules in aqueous and aqueous-saline solutions with changes in solution parameters (pH, addition of iron chloride III). At values of pH< (3.56±0.15) and pH> (10.4±0.2), the hemoglobin molecule underwent conformational changes, resulting in the disintegration of the quaternary structure into αβ−dimers and individual α− and β−globules. As a result of the study, it was found that the addition of FeCl3 to aqueous solutions of hemoglobin increases the size and mass of scattering particles, which can be explained by the adsorption of Fe3+ ions on the protein surface. However, upon reaching a certain concentration of FeCl3, the pH of the solution was lowered to such an extent that it caused conformational changes in hemoglobin, leading to the disintegration of its quaternary structure. These results can be taken into account when creating medicinal drugs for the treatment of anemia and other diseases associated with the hemoglobin protein.

Optimization of coagulation-flocculation process for wastewater treatment from vegetable oil refineries using chitosan as a natural flocculant

Vegetable oil refinery wastewater (VORW) is a significant source of refractory pollutants necessitating efficient treatment prior to discharge. This study investigates the treatment of VORW via coagulation-flocculation using ferric chloride (FeCl3) as a coagulant and chitosan as a natural flocculant. Central Composite Design (CCD) is employed to optimize the treatment process and assess the interplay of experimental factors. The study evaluates turbidity, COD, and polyphenols as responses, with pH, FeCl3 concentration, chitosan dosage, and agitation time as independent factors.The results showed that the optimal conditions identified include pH 6, FeCl3 dosage of 1.6 g/L, chitosan dosage of 13.4 mg/L, and agitation time of 26 min, resulting in 100 % turbidity removal, 86 % COD reduction, and 90 % polyphenol removal. The analysis of variance indicated that the established models were significant and that they are characterized by a good fit (R2 in the order of 0.95, 0.96, and 0.96 for turbidity, COD, and polyphenols, respectively).These findings highlight the efficacy and sustainability of the coagulation-flocculation process with chitosan, offering a practical, rapid, and cost-effective solution for VORW treatment and environmental preservation.

Investigation of leaching of nickel sulfide flotation tailings to recover valuable metals

The global transition towards renewable energy, driven by low-carbon theories and technologies, has resulted in an increasing surge in the demand for critical and unique elements, of which nickel (Ni) and copper (Cu) are encompassed. In this investigation, using acid leaching, the recovery of such elements from polymetallic tailings to supplement conventional extraction processes was studied. The effective leaching parameters were investigated and optimized to enhance the simultaneous recovery of Ni, Cu, cobalt (Co), chromium (Cr), and manganese (Mn) from the tailings sample. To this end, the response surface methodology (RSM) was employed, with sulfuric acid (H2SO4) concentration (0–20 g/L), ethylenediaminetetraacetic acid (EDTA) concentration (0–20 g/L), ferric chloride (FeCl3) concentration (0–20 g/L), leaching temperature (20–80 °C), and leaching time (4–12 h) as independent variables. The analysis of variance depicted that ferric chloride concentration was the most prominent process parameter for the recovery of Ni, Cu, Co, and Mn. The recovery of Cr was contingent to leaching temperature and sulfuric acid addition. Ensuing tests under the optimal conditions resulted in the recovery of 100.0 % Cu, 89.8 % Co, 42.1 % Cr, and 100.0 % Mn in addition to 93.7 % Ni. The kinetics was also studied using the shrinking-core model. Kinetic data indicates that the dissolution of Ni, Cu, Co, and Cr is governed by the chemically controlled model, while that of Mn by the diffusion control model. The activation energies as per the Arrhenius equation are estimated as 32.43, 36.78, 34.88, 24.02, and 29.18 kJ/mol for Ni, Cu, Co, Cr and Mn.

Research on the in-situ flocculation behavior of polyferric silicate for enhancing the lithium leachability in lithium-rich clay

The expansion of global lithium demand urgently requires efficient extraction technologies for lithium-rich clay recourse. However, the encapsulation of polysilicate products in the acidic leaching system impedes the migration of lithium from the mineral to the solution, resulting in a low recovery rate of lithium. Here, this study proposes an in-situ flocculation mechanism of Fe3+ on the polysilicate to reconstruct the surface structure, enhancing the leaching efficiency of lithium. Results showed that the flocculation of Fe3+ approaches the Si-O surface and reacts with silicate to form the polyferric silicate (Fe3Si2O5(OH)4). This special configuration eliminates the wrapping and adsorption effect of polysilicate while promotes the diffusion of Li+. Increased FeCl3 concentration and higher leaching temperature are beneficial for the leaching efficiency of Li. Under optimized conditions, the Li leaching efficiency in the FeCl3 leaching system reaches up to 92.81 %. This work introduces Fe3+ to overcome the limiting effect of polysilicate during acidic leaching, and affords extraordinary recovery of lithium from clay resources.

A composite gel formed by konjac glucomannan together with Nano-CF obtained by FeCl3-citric acid hydrolysis as a potential fat substitute

This study aims to fabricate composite gels using nano citrus fiber (Nano-CF) derived from the hydrolysis process of citric acid (CA) with FeCl3, with a simultaneous exploration of its potential as an substitute to fats. Investigation of varying FeCl3 concentrations (0.01 to 0.03 mmol/g of CA) revealed a significant enhancement in the water-holding and oil-retention capacity of the Nano-CF. The meticulous synthesis of the composite gels involved integrating nano citrus fibers with konjac glucomannan (KGM) through high-speed shearing, followed by a comprehensive evaluation of its microstructure and physicochemical attributes. Increasing the Nano-CF concentration within the gels led to a synergistic interaction with KGM, resulting in enhanced viscosity, improved thermal stability, and restricted water molecule mobility within the system. The gels initially displayed reduced firmness, resilience, and adhesive characteristics, followed by subsequent improvement. When the ratio of Nano-CF to KGM was 0.5:1, the composite gels exhibited texture parameters, viscosity, and viscoelastic stability comparable to whipped animal cream formulations. These findings provide a new idea for the application of Nano-CF/KGM composite gels in whipped cream.

Chemically doped-graphene FET photodetector enhancement via controlled carrier modulation with an iron(III)-chloride

Graphene is an excellent material among the family of 2D materials due to its electronic and optoelectronic properties. The intentional modification of its electronic structure via doping processes holds immense significance regarding tailoring its properties for specific applications. We comprehensively investigated p-type doping in few-layer graphene field-effect transistors (FETs) on SiO2/Si substrates by utilizing Iron(III)-chloride (FeCl3) dopant solutions with varying concentrations that range from 5 mM to 50 mM in this study. The successful doping was confirmed via a meticulous Raman spectroscopy analysis, which revealed notable shifts in the peak positions and peak broadening post-doping. Electrical measurements, which include transfer curves at a fixed biasing voltage, provided further confirmation, which demonstrates a distinctive shift in the Dirac point from −1 V to +25 V when the FeCl3 concentrations were changed from 5 mM to 50 mM. The impact of doping on the photoresponse of the graphene device was systematically explored. The device exhibited a significant increase in responsivity and external quantum efficiency following the p-type doping, which indicates an enhanced performance in photodetection. This research validates the successful p-type doping of graphene and underscores its implications regarding optimizing the electrical and optoelectronic properties of graphene-based devices, which confirms its potential for advanced applications for electronic and optoelectronic technologies.

Combination of membrane bioreactor with chemical coagulation for the treatment of real pharmaceutical wastewater: Comparison of simultaneous and consecutive pre-treatment of coagulation on MBR performance

In this work, the combination of the coagulation process with the MBR system to reclaim effluent in pharmaceutical industries was investigated. In this research, comparison/concentration optimization of two modes of integrations, including simultaneous; one-step one pot, and consecutive coagulation MBR were investigated. Results showed that COD removal in simultaneous and consecutive modes at optimum values were 85 % and 95.8 %, respectively, which were considerably higher than that of control MBR; 53.89 %. The total fouling ratio for control MBR, simultaneous, and consecutive modes at optimum conditions were 70.69 %, 37.3 %, and 42.5 %, respectively, confirming that the integrated coagulation process and MBR system were considerably effective. Analyzing the secreted metabolite, e.g. protein, carbohydrate, and LB/TB-EPS ratio in the MBR tank as well as on the membrane surface showed that the charge-neutralization and entrapment of bio-foulants by aggregated clots during the coagulation hinder the adhesion of the biofouling agents on the membrane surface, therefore in-line with the flux attenuation trend, lower metabolite concentration results in less membrane fouling. It was found that simultaneous coagulative MBR with 100 mg/L FeCl3 concentration demonstrates better fouling mitigation in comparison with consecutive (even with poly aluminum chloride; PACl as coagulant aid) MBR, while the latter mode shows better performance in terms of wastewater treatment. These findings open avenues for future techno-economic assessments of a coagulation-assisted MBR, providing a cost-effective solution for treating high-strength wastewater on a larger scale.

Effect of FeCl3 concentration in chemically enhanced primary treatment on the performance of a conventional wastewater treatment plant. A case study

The effect of coagulant dosage in a chemically enhanced primary treatment (CEPT) on the performance of a conventional wastewater treatment plant (WWTP) has been investigated. Lab-scale experiments simulations were carried out in order to evaluate the effect of coagulant addition on the primary settling performance. In these experiments, FeCl3 was used as coagulant. Later, the WWTP was theoretically simulated using a commercial software (WEST®) to evaluate the effect of coagulation/flocculation on the global system, based on the results obtained at lab-scale. According to these results, the CEPT modifies the organic matter balance in the WWTP, decreasing the contribution of readily (SS) and slowly (XS) biodegradable fractions of COD to the aerobic biological process up to 27.3% and 80.8%, respectively, for a dosage of FeCl3 of 24 mg L−1. Consequently, total suspended solids in the aerobic reactor and the secondary purged sludge decreased up to 33% and 13%, respectively. However, the influence on effluent quality was negligible. On the contrary, suspended solids concentration in the sludge to be treated by anaerobic digestion increased, mainly regarding the Ss and Xs fractions, which caused an 8.1% increase in biogas production potential, with approximately 60% of CH4 concentration.

Investigating the Optimization of Magnetic Biochar Production from Rubber Seed Shells for Enhanced Cr(VI) Removal Efficiency

This study aimed to utilize agricultural and produce low-cost magnetic biochar from rubber-seed shells using ferric chloride (FeCl3) as a transition metal. The study employs Response Surface Methodology (RSM) based on the Box-Behnken Design (BBD) to determine optimal production conditions for removing chromium (Cr(VI)). The effect of preparation conditions such as pyrolysis temperature (500-700 °C), duration (90-180 min), and impregnation (1-3 M) on the produced magnetic biochar was examined. The optimal condition was demonstrated based on yield percentage and Cr(VI) removal efficiencies. The study revealed that the optimal conditions for producing magnetic biochar from rubber seed shells were a pyrolysis temperature of 580 °C, a pyrolysis time of 130 min, and a FeCl3 concentration of 3 M. Under these conditions, a yield of 48.63% was achieved, and the removal efficiencies for Cr(VI) were 41.29%. This research suggests that utilizing agricultural waste products from rubber seed shells may be a viable and economical method for producing magnetic biochar, which can serve as an efficient adsorption agent.

Modified two-step etching method for the synthesis of Ti3C2 MXene with enhanced electrochemical performance

This work presents a modified etching method for the synthesis of Ti3C2 MXene. The process involves two steps: washing Ti3AlC2 with a low concentration of HF and etching Ti3AlC2 with varying concentrations of FeCl3. FeCl3 can etch the Al layers of Ti3AlC2 by a metal displacement reaction at room temperature, resulting in Ti3C2 nanosheets with an accordion-like morphology. The obtained Ti3C2 MXene was tested as a working electrode for supercapacitors, achieving a maximum specific capacitance of 213.2F/g at 0.5 A/g in a 6 M KOH electrolyte solution, which is higher than that of a Ti3C2 electrode without modification. The method is simple, efficient and reduces the use of HF. This work shows the possibility of synthesizing various MXene-based frameworks using metallic cations with higher redox potentials.

Two distinct non-ribosomal peptide synthetase-independent siderophore synthetase gene clusters identified in Armillaria and other species in the Physalacriaceae.

Siderophores are important for ferric iron solubilization, sequestration, transportation, and storage, especially under iron-limiting conditions such as aerobic conditions at high pH. Siderophores are mainly produced by non-ribosomal peptide synthetase-dependent siderophore pathway, non-ribosomal peptide synthetase-independent siderophore synthetase pathway, or the hybrid non-ribosomal peptide synthetases/non-ribosomal peptide synthetases-independent siderophore pathway. Outcompeting or inhibition of plant pathogens, alteration of host defense mechanisms, and alteration of plant-fungal interactions have been associated with fungal siderophores. To understand these mechanisms in fungi, studies have been conducted on siderophore biosynthesis by ascomycetes with limited focus on the basidiomycetes. Armillaria includes several species that are pathogens of woody plants and trees important to agriculture, horticulture, and forestry. The aim of this study was to investigate the presence of non-ribosomal peptide synthetases-independent siderophore synthetase gene cluster(s) in genomes of Armillaria species using a comparative genomics approach. Iron-dependent growth and siderophore biosynthesis in strains of selected Armillaria spp. were also evaluated in vitro. Two distinct non-ribosomal peptide synthetases-independent siderophore synthetase gene clusters were identified in all the genomes. All non-ribosomal peptide synthetases-independent siderophore synthetase genes identified putatively encode Type A' non-ribosomal peptide synthetases-independent siderophore synthetases, most of which have IucA_IucC and FhuF-like transporter domains at their N- and C-terminals, respectively. The effect of iron on culture growth varied among the strains studied. Bioassays using the CAS assay on selected Armillaria spp. revealed in vitro siderophore biosynthesis by all strains irrespective of added FeCl3 concentration. This study highlights some of the tools that Armillaria species allocate to iron homeostasis. The information generated from this study may in future aid in developing molecular based methods to control these phytopathogens.

Mice expressing nonpolymerizable fibrinogen have reduced arterial and venous thrombosis with preserved hemostasis

AbstractElevated circulating fibrinogen levels correlate with increased risk for both cardiovascular and venous thromboembolic diseases. In vitro studies show that formation of a highly dense fibrin matrix is a major determinant of clot structure and stability. Here, we analyzed the impact of nonpolymerizable fibrinogen on arterial and venous thrombosis as well as hemostasis in vivo using FgaEK mice that express normal levels of a fibrinogen that cannot be cleaved by thrombin. In a model of carotid artery thrombosis, FgaWT/EK and FgaEK/EK mice were protected from occlusion with 4% ferric chloride (FeCl3) challenges compared with wild-type (FgaWT/WT) mice, but this protection was lost, with injuries driven by higher concentrations of FeCl3. In contrast, fibrinogen-deficient (Fga−/−) mice showed no evidence of occlusion, even with high-concentration FeCl3 challenge. Fibrinogen-dependent platelet aggregation and intraplatelet fibrinogen content were similar in FgaWT/WT, FgaWT/EK, and FgaEK/EK mice, consistent with preserved fibrinogen–platelet interactions that support arterial thrombosis with severe challenge. In an inferior vena cava stasis model of venous thrombosis, FgaEK/EK mice had near complete protection from thrombus formation. FgaWT/EK mice also displayed reduced thrombus incidence and a significant reduction in thrombus mass relative to FgaWT/WT mice after inferior vena cava stasis, suggesting that partial expression of nonpolymerizable fibrinogen was sufficient for conferring protection. Notably, FgaWT/EK and FgaEK/EK mice had preserved hemostasis in multiple models as well as normal wound healing times after skin incision, unlike Fga−/− mice that displayed significant bleeding and delayed healing. These findings indicate that a nonpolymerizable fibrinogen variant can significantly suppress occlusive thrombosis while preserving hemostatic potential in vivo.

Modulation of optical band gap and conductivity of polyindoles with concentrations of FeCl3 and APS

Conducting Polyindoles (PIn-I and PIn-II) samples were synthesized via chemical oxidative polymerization in aqueous solution at a range of concentrations (0.3–0.9 M) of anhydrous FeCl3 and Ammonium persulfate (APS) at 25 ± 1 °C. Techniques such as FTIR spectrograph confirm various bond absorptions which give the identity of PIns, the morphology has been examined by SEM and XRD, while the thermal analysis of the prepared sample was studied by employing TGA-DSC. UV–Vis spectroscopy has been used to analyze complex optical parameters like band gap, refractive index, dielectric constant, and optical conductivity. The produced PIns exhibit absorption around 340–410 nm and results in the optical band gap in the range of 2.906 to 2.929 eV for the PIn-I series (with FeCl3) and 2.673 to 2.734 eV for the series of PIn-II (with APS). The samples synthesized employing 0.3 M FeCl3 and 0.9 M APS were found to have the lowest optical band gap energies of 2.906 eV and 2.673 eV, respectively. The experimental studies reveal that the optical conductivity, particle size, and crystallinity of PIn can be optimized with the different types of oxidants and their varying concentrations. The results conclude that the oxidizing agents having high reduction potential offer better electron transport and thus lower band gap and high optical conductivity. Due to the above-mentioned optical band gaps and high environmental stability, PIns have potential applications in optical devices.

Performance of a rotating packed bed with blade packings in synthesizing nano-sized Fe3O4 particles

Nano-sized Fe3O4 particles were continuously synthesized in the rotating packed bed with blade packings where the rotational speed was set at 1800 rpm, the liquid flow rate of aqueous FeCl2/FeCl3 was kept at 0.5 L/min, and the liquid flow rate of aqueous NaOH was maintained at 0.5 L/min with the chemical co-precipitation route that the synthesis temperature was fixed at 25 °C, the FeCl2 concentration was fixed at 0.15 mol/L, the FeCl3 concentration was fixed at 0.3 mol/L, and the NaOH concentration was fixed at 1.2 mol/L. The average crystallite size and mean particle size of the as-synthesized nano-sized Fe3O4 particles were 12.7 nm and 10.9 nm, respectively. The rate of continuous synthesis of nano-sized Fe3O4 particles was 23.6 kg/day. The as-synthesized nano-sized Fe3O4 particles exhibited a superparamagnetic characteristic at 25 °C. Furthermore, the saturation magnetization of the as-synthesized nano-sized Fe3O4 particles was 66.4 emu/g. The as-synthesized nano-sized Fe3O4 particles had the Type-IV isotherm for N2 adsorption-desorption with a BET specific surface area of 109.4 m2/g. The maximum Orange G adsorption capacity of the as-synthesized nano-sized Fe3O4 particles at 25 °C and pH 3 was 55.0 mg/g. This maximum Orange G adsorption capacity was much higher than that (5.7 mg/g) of the commercial nano-sized Fe3O4 particles that were purchased from Sigma-Aldrich (SA-Fe3O4) because the as-synthesized nano-sized Fe3O4 particles had a smaller mean particle size than SA-Fe3O4. Accordingly, the as-synthesized nano-sized Fe3O4 particles are a promising magnetic adsorbent in the removal of Orange G from water.

Photocatalytic ATRP Depolymerization: Temporal Control at Low ppm of Catalyst Concentration.

A photocatalytic ATRP depolymerization is introduced that significantly suppresses the reaction temperature from 170 to 100 °C while enabling temporal regulation. In the presence of low-toxicity iron-based catalysts and under visible light irradiation, near-quantitative monomer recovery could be achieved (up to 90%), albeit with minimal temporal control. By employing ppm concentrations of either FeCl2 or FeCl3, the depolymerization during the dark periods could be completely eliminated, thus enabling temporal control and the possibility to modulate the rate by simply turning the light "on" and "off". Notably, our approach allowed preservation of the end-group fidelity throughout the reaction, could be carried out at high polymer loadings (up to 2M), and was compatible with various polymers and light sources. This methodology provides a facile, environmentally friendly, and temporally regulated route to chemically recycle ATRP-synthesized polymers, thus opening the door for further opportunities.

On-chip electromembrane extraction using deep eutectic solvent and red-green-blue analysis by quick-response code readable customized application on a smartphone for measuring salicylic acid in pharmaceutical and plasma samples

The current work presents an on-chip electromembrane extraction (OC-EME) method using deep eutectic solvent followed by QR code-based red-green-blue (RGB) analysis for measuring salicylic acid (SA) in plasma and pharmaceutical samples. The RGB analysis was performed based on forming the SA-Fe3+ complex in the acceptor phase giving a purple solution. The QR code readable customized app provided rapid, easy, and cost-less qualification and quantification of SA with the aid of principal component analysis (PCA). Parameters affecting OC-EME, including the supported liquid membrane (SLM), pH of the donor and acceptor phases, applied voltage, and sample flow rate, were optimized. Also, the concentration of FeCl3, as a chromogenic reagent, and its reaction time with SA were investigated to find the best concentration-dependent signal. Under the optimized conditions, a good relationship was observed between the green intensity and SA concentration within the range of 1.0–100.0 mg l−1 (R2 = 0.9946) in water and 5.0–100.0 mg l−1 (R2 = 0.9902) in plasma. Intra- and inter-day RSDs% were obtained less than 4.7% and 7.7%, respectively. Finally, the method was successfully applied for measuring SA in foot corn treatment, Aspirin medicines, and human plasma, with relative recoveries between 89.0 and 129.2%.