Dispersive X-ray Diffraction Studies Research Articles

Palladium nanoparticles (Pd NPs) immobilized over polydopamine-functionalized Zn-Al mixed metal oxide as a novel nanocatalyst for synthesis of C-C bond via Suzuki-Miyaura coupling reactions

In recent times modified hydrotalcite like compounds formed with metal oxide layers has gained considerable importance as improved nanoparticle (NP) supports along with their unique electronic properties that inherently stabilizes the immobilized NPs. The present work demonstrates an adapted protocol towards the Pd NPs immobilized polydopamine modified Zn-Al mixed metal oxides (Zn-Al MMO@PDA/Pd NPs). Polydopamine was chosen as a biotemplate and a green reductant for the synthesis Pd NPs in situ without having any harsh reagent. Hitherto, this is the first design and biogenic synthesis of Pd NPs impregnated coordination on Zn-Al mixed metal oxides (Zn-Al MMO) and subsequent catalytic application towards the Suzuki-Miyaura coupling reactions. Subsequently, its physicochemical features were evaluated applying diverse methods like Field Emission Scanning Electron Microscopy (FE-SEM), X-ray elemental mapping (WDX), Energy Dispersive X-ray Spectroscopy (EDX) and X-Ray Diffraction (XRD) study. The Zn-Al MMO@PDA/Pd NPs nanocatalyst was isolated by centrifuger and stable enough to be reused for 8 consecutive times without considerable loss in activity.

Green Synthesis of Silver Nanoparticles: Their Optical and Rheological Properties

The goal of this work was to investigate the green synthesis of silver nanoparticles (Ag NPs) from aqueous Propolis (P) extract, and their optical and rheological properties. Using scanning electron microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and X-ray diffraction (XRD) studies nanostructure of the prepared Ag NPs were characterized. Further, the aforementioned study suggests that Ag NPs with an average size of around 23 nm have a well-developed polycrystalline cubic structure. In the UV-Vis absorption spectra, the surface plasmon resonance (SPR) peak showed maximum absorption at 418 nm. For an excitation energy corresponding to the wavelength 410 nm, photoluminescence (PL) spectra of Ag NPs exhibited emission peak at 495 nm. To explore temperature (T) dependent flow behaviour of biosynthesized colloidal Ag NPs dispersion in deionized (DI) water, flow curve studies under shear for T= 20, 30 and 40 °C were done using rheometer. The above study illustrated that the colloidal Ag NPs follows shear thickening non-Newtonian behaviour. Moreover, viscosity decreased as temperature increased, indicating that the silver nanofluids can exhibit more rational thermal performance under high temperature conditions.

Effect of selected green corrosion inhibitors on SO2 removal during carbon steel corrosion in aqueous solutions of ammonia and histidine

To understand the feasibility of using carbon steel in the flue gas desulfurization process, the corrosion protection of carbon steel was investigated by adding four green corrosion inhibitors (12-aminolauric acid; 4-carboxyphenylboronic acid; 1,2,3-benzotriazole; and L-methionine) to an ammonia solution containing histidine as the SO2 absorbent. The effects of the corrosion inhibitors on the corrosion rates of carbon steel and SO2 absorption performance were investigated. We observed that 1,2,3-benzotriazole was the most effective corrosion inhibitor, reducing the corrosion rate by 73 % and increasing the SO2 absorption loading by 8.3 % compared to other corrosion inhibitors. Scanning electron microscopy/energy dispersive X-ray spectroscopy and X-ray diffraction studies were conducted to understand the corrosion inhibition behavior of 1,2,3-benzotriazole. The formation of the Fen-(SO2-BTA)m complex and its subsequent adsorption on the carbon steel surface blocked active sites and inhibited corrosion. This study demonstrated the feasibility of effectively using carbon steel under harsh environmental conditions such as in desulfurization.

An experimental investigation on the combined effect of plastic deformation and grain size variation on the acoustic nonlinearity parameter.

The combined effect of grain size variation and plastic deformation on the acoustic nonlinearity parameter has been investigated in an austenitic stainless-steel material of grade 304. The nonlinear behavior of this parameter with grain growth has deviated to linear fit with deformation. This is due to the interaction of elastic waves with the strain-induced dislocation substructure in the grains. The normalized mean square strain of the deformed specimens has been estimated through angle dispersive x-ray diffraction studies using a synchrotron source, and this has been correlated with the change in the acoustic non-linearity parameter with deformation. The nonlinearity parameter is found to be very sensitive to the plastic deformation even in the presence of grain size variations. The results infer that the variations in the nonlinearity parameter can be used to have an estimate of the extent of localized deformations often occurring during the fabrication of metallic components.

Preparation of chitosan/sodium lignosulfonate/Ag NPs: A potent and green bio-nanocomposite for the treatment of glucocorticoid induced osteoporosis in rats

• CS/NaLS/Ag NPs have antioxidant potentials. • CS/NaLS/Ag NPs have non-cytotoxicity effects. • The results of the CS/NaLS/Ag NPs have revealed that the recent nanocomposite has been formulated as the best. • The treatment of osteoporosis by CS/NaLS/Ag NPs was proven in the recent study. In this study we report the green synthesis of nontoxic, stable, and small size silver nanoparticle by using chitosan/sodium lignosulfonate hydrogel with capping/reducing ability for the synthesis of CS/NaLS/Ag NPs. The prepared bio-nanocomposite were characterized by advanced physicochemical techniques like Fourier Transformed Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX) and X-ray Diffraction (XRD) study. It has been established that CS/NaLS/Ag NPs have a spherical shape with a mean diameter from 20 to 30 nm. Administration of CS/NaLS/Ag NPs (5 µg/kg/day, po, for 30 days) and risedronate (20 µg/kg, sc, five times a week for 30 days) following methyl prednisolone sodium succinate (10 mg/kg, sc, thrice a week for 4 weeks) induced osteoporosis in Wistar rats showed an increase in the serum levels of bone mineral content markers and a decrease in serum and urinary levels of bone resorption markers. An incline in strength of femur and tibia was seen particularly with 5 µg/kg of CS/NaLS/Ag NPs. Maintenance of calcium homeostasis, formation of collagen and scavenging of free radicals can plausibly be the mode of action of CS/NaLS/Ag NPs thereby combating osteoporosis induced by glucocorticoids.

Multicycle flash sintering of cubic Y2O3-stabilized ZrO2: An in situ energy dispersive synchrotron x-ray diffraction study with high temporal resolution

The current induced unit cell volume changes, (111) Bragg peak full width at half maximum (FWHM) and its integrated intensity in 8 % Y2O3 stabilized ZrO2 (8 %YSZ) solid state electrolyte was monitored during a triple-flash sintering experiment by in situ energy dispersive x-ray diffraction using a polychromatic synchrotron probe (max, photon energy 200 keV) with 2 second temporal resolution. The first spontaneous singularity in the unit cell volume (+0.54 %) was observed at 899 °C under 15 V/mm applied field intensity, which was associated with 13 mA/mm2 current draw and an increase in density to 97 %. Following anelastic relaxation of the unit cell volume under open circuit conditions, the same applied field was applied twice in a row which resulted in additional induced singularities at 925 °C (+0.48 %) and 944 °C (+0.42 %). A floating baseline, which was above the thermal expansion baseline, was observed from 833 to 969 °C and was attributed to Joule heating. The singularity at 899 °C is associated with a sharp change in (111) FWHM and a 34 % decrease in integrated peak area that was attributed to changes in the distribution of oxygen vacancies and the changes in their concentration as induced by the applied field in the spontaneous transient stage of flash sintering.

Nephroprotective properties of chitosan/sodium lignosulfonate/Au nanoparticles in streptozotocin-induced nephropathy in mice: Introducing a novel therapeutic drug for the treatment of nephropathy

In this study, we report the green synthesis of nontoxic, stable, and small size gold nanoparticle by using chitosan/sodium lignosulfonate hydrogel with capping/reducing ability for the synthesis of CS/NaLS/Au NPs. The prepared bio-nanocomposite were characterized by advanced physicochemical techniques like Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX) and X-ray Diffraction (XRD) study. It has been established that CS/NaLS/Au NPs have a spherical shape with a mean diameter from 20 to 30 nm. Diabetes was induced by administration of 60 mg/kg of streptozotocin (STZ) intraperitoneally in 100 mature male mice and they were randomly divided into 5 groups. The negative control group received normal saline and treatment groups received glibenclamide with dose 0.5 mg/kg and 10 and 40 μg/kg of CS/NaLS/Au NPs through gavage for 50 days. In addition, one group considered as positive control (in treated-diabetic). On the last day, serum levels of samples blood glucose, urea and creatinine were measured. After tissue processing, 5 μm sections of the kidneys were prepared and they were stained by periodic acid Schiff (PAS) and used for stereological analysis. In the antioxidant test, the IC50 of CS/NaLS/Au NPs and BHT against DPPH free radicals were 117 and 86 µg/mL, respectively. In the cellular and molecular part of the recent study, the treated cells with CS/NaLS/Au NPs were assessed by MTT assay for 48 h about the cytotoxicity properties on normal (HUVEC) cell line. The increased levels of blood glucose and urea were decreased ( p < 0.05) significantly in CS/NaLS/Au NPs-treated groups as compared to the untreated diabetic. The kidney weight, kidney volume (Volume of cortex, medulla, glomerulus, proximal and distal tubules, collecting ducts, loop of Henle, interstitial tissues, and vessels) and kidney structures length (length of proximal and distal tubules, collecting ducts, loop of Henle, and vessels) decreased significantly ( p < 0.05) after treatment with high dose of CS/NaLS/Au NPs ( p < 0.05). According to the obtained results, CS/NaLS/Au NPs can regulates the levels of blood glucose and urea and inhibits from kidney damages in STZ-induced diabetic mice. This study suggested CS/NaLS/Au NPs as an antidiabetic and nephroprotective drug in the developing countries.

Pectin mediated green synthesis of CuO nanoparticles: evaluation of its cytotoxicity, antioxidant and anti-human cervical cancer properties

Regarding applicative, facile, green chemical research, a bio-inspired approach is being reported for the synthesis of CuO nanoparticles by pectin (PEC) as a natural reducing and stabilizing agentin alkaline medium without using any toxic reducing agent. The biosynthesized CuO NPs@Pectin were characterized by advanced physicochemical techniques like ultraviolet–visible (UV–Vis), Fourier Transformed Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX) and X-ray Diffraction (XRD) study. It has been established that pectin-stabilized copper nanoparticles have a spherical shape with a mean diameter from approximately 10 nm. To survey the cytotoxicity and anti-human cervical cancer effects of CuO NPs@Pectin, MTT assay was used on C-33 A [c-33a], SiHa, Ca Ski, DoTc2 4510, HT-3 and LM-MEL-41 cell lines. The resulting IC50 values of the CuO NPs@Pectin against C-33 A [c-33a], SiHa, Ca Ski, DoTc2 4510, HT-3 and LM-MEL-41 cell lines were 231, 214, 243, 376, 315 and 169 µg/mL, respectively. Antioxidant properties of CuO NPs@Pectin were surveyed through the DPPH test in presence of butylated hydroxytoluene as the positive control. The CuO NPs@Pectin inhibited half of the DPPH molecules in the concentration of 98 µg/mL. The cell viability of the treated cell lines was found to reduce dose-dependently over the CuO NPs@Pectin nanocomposite. After approving the above results in the clinical trial studies, the CuO NPs@Pectin can be used as a chemotherapeutic drug for the treatment of several types of cervical cancers.

Laser induced plant leaf extract mediated synthesis of CuO nanoparticles and its photocatalytic activity

Metal nanoparticles furnished by the green synthesis approach have exhibited fascinating attributes owing to their biocompatibility with biomolecules, and their rapid environmentally friendly synthesis. On copper oxide (CuO) nanoparticles, a laser induced bio reduction work has been accomplish using Centella asiatica aqueous extract at room temperature is the pioneer in the field. This synthesis technique is easy, fruitful, eco-friendly, and counterfeit for the size-tunable synthesis of diverse shapes of stable copper nanoparticles. UV–visible spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), Energy - Dispersive X-ray Spectroscopy (EDX), X-ray diffraction (XRD) and photodegradation study have astounding properties of regulating the formation, crystalline nature, and morphology of an integrated specimen. Moreover, the obtained copper oxide nanoparticle has the tendency to decrease the absorbance maximum value of methylene blue because of the catalytic activity posed by these nanoparticles on the reduction of methylene blue by Centella asiatica. It has been studied and confirmed by UV–visible spectrophotometer, and it has been recognised as an electron relay effect.

Green preparation of copper nanoparticle-loaded chitosan/alginate bio-composite: Investigation of its cytotoxicity, antioxidant and anti-human breast cancer properties

In this study, an eco-friendly and low-cost procedure for the in situ fabrication of Cu nanoparticles by using chitosan/alginate hydrogel. The prepared Cu [email protected]/Alg nanocomposite were characterized by advanced physicochemical techniques like Fourier Transformed Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX) and X-ray Diffraction (XRD) study. It has been established that chitosan/alginate-capped gold nanoparticles have a spherical shape with a mean diameter from 10 to 20 nm. In the cellular and molecular part of the recent study, the treated cells with Cu [email protected]/Alg nanocomposite were assessed by MTT assay for 48 h about the cytotoxicity and anti-human breast cancer properties on normal (HUVEC) and breast cancer cell lines i.e. infiltrating lobular carcinoma of breast (UACC-3133), inflammatory carcinoma of the breast (UACC-732), and metastatic carcinoma (MDA-MB-453). In the antioxidant test, the IC50 of Cu [email protected]/Alg nanocomposite and BHT against DPPH free radicals were 344 and 193 µg/mL, respectively. The IC50 of Cu [email protected]/Alg nanocomposite were 297, 386, and 359 µg/mL against KYSE-270, OE33, and ESO26 cell lines, respectively. The viability of malignant breast cell line reduced dose-dependently in the presence of Cu [email protected]/Alg nanocomposite.

Design and synthesis of chitosan/agar/Ag NPs: A potent and green bio-nanocomposite for the treatment of glucocorticoid induced osteoporosis in rats

In this work we have demonstrated the green synthesis of stable and mono-dispersed Ag NPs using chitosan/Agar hydrogel having reducing/stabilizing ability avoiding any toxic reagents. Agarose was used as a green reductant for the synthesis of Ag NPs which gets stabilized by chitosan. The in situ prepared Ag NPs@CS/Agar nano bio-composite were characterized by advanced physicochemical techniques like Fourier Transformed Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX) and X-ray Diffraction (XRD) study. The Ag NPs encapsulated by CS/Agar bio-composite have a spherical shape with a mean diameter from 10 to 15 nm. Towards its bioapplication, the Ag NPs@CS/Agar nano bio-composite was administered by 5 µg/kg/day for 30 days in comparison to methyl prednisolone sodium succinate by 10 mg/kg, sc, thrice a week for 4 weeks over Wistar rats having glucocortcoid induced osteoporosis. This showed a significant increase in the serum levels of bone mineral content markers and a decrease in serum and urinary levels of bone resorption markers. An inclination in strength of femur and tibia was seen particularly with 5 µg/kg of Ag NPs@CS/Agar nano bio-composite. Maintenance of calcium homeostasis, formation of collagen and scavenging of free radicals can be the plausible mode of action of this bio-nanocomposite thereby combating osteoporosis induced by glucocorticoids.

Green synthesis of silver nanoparticles using sodium alginate and tannic acid: characterization and anti-S. aureus activity

Multi-drug resistance and biofilm formation are a growing problem in the treatment of Staphylococcus aureus contamination. Advances in nanotechnology allow the synthesis of metal nanoparticles that can be assembled into complex architectures for controlling bacterial growth. This study aims to investigate the ultrasonic-assisted green synthesis of silver nanoparticles (AgNPs) by tannic acid (TA) and sodium alginate (Na-Alg) as the reducing and stabilizing agents, respectively, and evaluation of their antibacterial and antibiofilm activities. The UV–Vis spectroscopy and transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), zetasizer, FT-IR spectroscopy, and X-ray diffraction (XRD) studies showed that the optimum produces were spherical, stable, and monodispersed AgNPs with an average size of particle sizes of 18.52 ± 0.07 nm. The antibacterial and antibiofilm activities of the AgNPs loaded TA/Na-Alg constructs against S. aureus ATCC 6538 were investigated. The minimum inhibitory concentration (MIC) of the AgNPs was 31.25 μg/mL. After exposure to the AgNPs, planktonic S. aureus showed irreversible cell membrane damage, decreased cell viability, and changes in cellular morphology. In addition, the AgNps significantly inhibited S. aureus biofilm formation at 1/32 MIC. The biofilm elimination rate was 58.87% after exposure to MIC AgNPs. The results suggested that the development of AgNPs loaded TA/Na-Alg constructs with biomedical potentialities obtained through a simple, green, and cost-effective approach, may be suitable for the formulation of a new strategy for combating S. aureus.

Towards Realizing High-Voltage Aqueous Zinc Batteries: An Investigation of the Zinc Anode in Concentrated Acetate-Based Electrolytes

Zinc-based aqueous battery systems are attractive for grid storage applications due to the inherent electrolyte safety, material non-toxicity, low cost, high volumetric capacity of zinc and the low polarizability of the zinc anode in aqueous solutions. Despite these key features, they possess lower energy density when compared to lithium-ion batteries primarily due to the limited working potential range for aqueous electrolytes. In addition, zinc hosts a slew of problems such as inhomogeneous material distribution upon cycling and the formation of inactive zinc species and dendrites, all of which contribute to capacity loss and ultimately, cell failure. Water-in-salt electrolytes (WiSE) have been found to be an effective strategy to expand the electrochemical window of aqueous electrolytes for high energy density aqueous-based batteries, including zinc batteries. There is a growing amount of literature on highly concentrated acetate-based electrolytes as low-cost and non-toxic WiSE for lithium, potassium, sodium and magnesium and zinc battery systems. However, work is scarce on the nature of zinc electrochemistry, morphology and reversibility in these concentrated electrolytes at realistic current densities (> 1 mA/cm2) and higher zinc utilization. Understanding the electrochemical behavior of zinc in this electrolyte system will significantly aid in the development of a high voltage zinc aqueous battery.In this work, the zinc electrochemical performance and surface morphology is studied in highly concentrated bi-salt potassium acetate (KOAc)-zinc acetate (Zn(OAc)2) electrolytes. The impact of the high concentration on the electrochemical working window of the electrolytes is measured using potential sweep and constant-current techniques. As the acetate concentration is varied from 1 m to 32 m, the largest electrochemical window is measured at 3.33 V for 31 m KOAc+ 1 m Zn(OAc)2. Zinc half cells are cycled at current densities of 1-5 mA/cm2 to examine zinc reversibility with respect to zinc depth-of-discharge (DOD) in these electrolytes. The zinc discharge product is visualized by in-operando optical microscopy as a function of the potential and is observed to be a zinc plating/stripping phenomenon in contrast to zinc dissolution/precipitation typically observed in alkaline media. Energy dispersive X-ray spectroscopy and X-ray diffraction studies display the minor presence of zinc oxide and zinc hydroxide after repeated cycling. Cloud point measurements are performed to measure the phase stability of these electrolytes at 5-25ºC as a function of acetate concentration, which show that concentrations below (and including) 27 m KOAc + 1 m Zn(OAc)2 does not induce crystallization at these temperatures. Preliminary measurements using spectroscopic techniques such as Raman and nuclear magnetic resonance (NMR) spectroscopy are conducted to elucidate ion solvation structures as a function of acetate concentration. Overall, the current and proposed studies are fruitful in understanding the relationship between zinc anode and the concentrated acetate-based electrolytes in the pursuit of a high-voltage aqueous zinc battery.

Data on corrosion inhibition effect of Stylosanthes gracilis extract on UNS S30403 austenitic stainless steel in dilute acid solution

This article presents data on the evaluation of Stylosanthes gracilis extract as corrosion inhibitor for 304 L in H2SO4 solution. The data were obtained from weight loss measurements, energy dispersive spectroscopy and X-ray diffraction studies. The extract reduced the rate of corrosion on SS 304l in H2SO4 solution at an optimum concentration of 1.2 g/L with inhibition efficiency of about 87.81% and corresponding surface coverage of 0.878. The corrosion rate of 0.232 mm/yr was observed in the inhibited sulphuric acid as against 1.904 mm/yr in the blank acid respectively at 240 h of exposure of the specimens. At 2400 h of exposure, the observed corrosion rate was 0.228 mm/yr with an efficiency of 74.21%. Whereas the extract's efficacy was slightly influenced by time, concentration has a profound effect on the extract's protection capability. The decrease in the efficiency of the extract after 2400 h is 13.6% suggesting the good stability with time.

Tri-molybdenum phosphide (Mo3P) and multi-walled carbon nanotube junctions for volatile organic compounds (VOCs) detection

Detection and analysis of volatile organic compounds' (VOCs) biomarkers lead to improvement in healthcare diagnosis and other applications such as chemical threat detection and food quality control. Here, we report on tri-molybdenum phosphide (Mo3P) and multiwalled carbon nanotube (MWCNT) junction-based vapor quantum resistive sensors (vQRSs), which exhibit more than one order of magnitude higher sensitivity and superior selectivity for biomarkers in comparison to pristine MWCNT junctions based vQRSs. Transmission electron microscope/scanning tunneling electron microscope with energy dispersive x-ray spectroscopy, x-ray diffraction, and x-ray photoelectron spectroscopy studies reveal the crystallinity and the presence of Mo and P elements in the network. The presence of Mo3P clearly enhanced the performance of vQRS as evidenced in sensitivity and selectivity studies. The vQRSs are stable over extended periods of time and are reproducible, making them a potential candidate for sensing related applications.

Growth of covellite crystal onto azurite surface during sulfurization and its response to flotation behavior

In this work, the growth of copper sulfide crystal onto azurite surfaces during sulfurization and its response to flotation are investigated. Filed emission scanning electron microscopy-energy dispersive X-ray spectroscopy (FESEM) and X-ray diffraction (XRD) studies confirmed that the sulfurization of azurite is not limited to the mineral surface, but rather penetrates into the bulk to form covellite crystal (syn-CuS), creating favorable conditions for the stable adsorption of xanthate and greatly promoting the azurite flotation. Additionally, as demonstrated by X-ray photoelectron spectroscopy (XPS) and time of flight secondary ion mass spectrometry (TOF-SIMS) analyses, a redox reaction occurred during this process, and Cu(Ⅱ) onto the mineral surface was reduced to Cu(I). Correspondingly, reduced S2- was oxidized to (S2)2-, (Sn)2-, and even to deeper oxidation state S0, (SxOy)n- and SO42-. Excess sodium sulfide strengthens copper sulfide to form onto the azurite surface, and provides enough raw material for crystal copper sulfide to grow, resulting in the formation of “flake-like” covellite with a better crystallinity. However, the floatability of azurite decreased dramatically under this condition, because the generated massive colloidal copper sulfide in flotation pulp deteriorates the flotation environment, resulting in a decreased effective adsorption of collector onto azurite surfaces.

Biobased amphoteric aerogel derived from amine-modified clay-enriched chitosan/alginate for adsorption of organic dyes and chromium (VI) ions from aqueous solution

Naturally abundant and renewable macromolecular polysaccharides are now considered as green and sustainable adsorbent material for toxic effluent treatment. However, to deal with complex wastewater, the need for efficient amphoteric adsorbent is still a challenge. Herein a three-dimensional (3D) composite aerogel is prepared from dodecyl amine modified clay (kaolinite) enriched chitosan/alginate via freeze drying method and a post ionic crosslinking. The aerogel was characterized by Fourier transform infrared spectroscopy (FT-IRS), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), thermogravimetric analysis (TGA), X-ray diffraction (XRD), solubility test and adsorption studies. The thermal stability of aerogel was significantly higher than that of chitosan/alginate polymer matrix and substantially increased upon gradual addition of modified clay. The aerogel has ordered fishing net-like microstructure, and interconnected pores for dyes and metal ions adsorption. The adsorption capacities of composite aerogel on methylene blue, acid black and hexavalent chromium [Cr (VI)] ions was reached around 73.1, 71.5, and 62.4 mg/g respectively. The adsorption mechanism was electrostatic interaction and the mass ratio of chitosan and modified clay to alginate regulate the adsorption capacities for the anionic and cationic dyes. As a novel amphoteric adsorbent, the chitosan/alginate/modified clay composite aerogel showed the potential to remove both cationic, anionic dyes and metal ions from wastewaters. Moreover, the prepared biobased aerogel showed high adsorption efficiency in both acidic and basic media even after four cycles. The study demonstrated a high performance, low cost, with materials locally available, recyclable and promising candidate for industrial waste water treatment.

Microstructure transformation and high temperature oxidation properties of (FeCoNi)100-xAlx new-type high-entropy alloys

Oxidation properties of (FeCoNi)100-xAlx (x = 0, 5, 10, 15, and 20) high entropy alloys were investigated in air atmosphere at 800 °C. Combined scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS) sur-face analysis and X-ray diffraction (XRD) studies revealed that the addition of Al transformed the alloy from a single FCC solid solution structure to a mixed structure of FCC and BCC, from an unevenly distributed rod-like structure to a uniformly distributed dendritic structure. With the increase of Al content, the oxidation scale mainly consists of Al2O3 and Co2O3 and the oxidation kinetic curve of (FeCoNi)80Al20 HEA reaches the minimum value, which clarifies the superior high temperature resistance.

Electrodeposition of multilayer NiW alloy coating for improved anticorrosion performance

The attractiveness of electroplating linked to cathodic current density (CD) has tried to exploit here to the development of coatings of high corrosion resistance. Multilayer NiW alloy coatings of better anticorrosion performance were electrodeposited from a tartrate bath by periodic pulsing of CD between two values, during the process of deposition. The multilayer coatings of different configurations, in terms of composition and thickness of individual layers were developed by proper modulation of amplitude and duration of the square current pulse, respectively. The deposition conditions were optimized for best performance of the coatings against corrosion. Our experimental study revealed that under optimal condition, multilayer NiW coating having (NiW)1.0/3.0/120 configuration is almost six times more corrosion resistant than its monolayer coating, deposited from same bath for same duration. The reason for improved corrosion performance in multilayer NiW alloy coating was explained in the light of effect of larger interfaces affected due to layered deposition and confirmed by scanning electron microscopy analysis, energy dispersive spectroscopy and X-ray diffraction study. The mechanism of corrosion responsible for its better performance, in relation to its monolayer coating is given, and results are discussed.

Batch adsorption studies on surface tailored chitosan/orange peel hydrogel composite for the removal of Cr(VI) and Cu(II) ions from synthetic wastewater

Elimination of heavy metals from wastewater has been a significant process to improve the aquatic source’s quality. Various materials act as very effective adsorbents to remove heavy metals, which cause toxicity to plants and all other living organisms. Thus, the present work focuses on removing heavy metals chromium (Cr) and copper (Cu) ions containing wastewater using biodegradable and cost-effective chitosan-based hydrogel composite. The composite was prepared via chemical cross-linking of radical chitosan with polyacrylamide and N,N′-Methylene bisacrylamide and blended with orange peel. The synthesis of the adsorbent has been confirmed by using Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscopy – Energy dispersive X-ray analysis (SEM-EDAX) and X-ray diffraction (XRD) studies. The adsorption power of the composite of metal ions at different time, pH, adsorbent dosages, different metal ion concentrations were analyzed by using Atomic Absorption Spectroscopy (AAS). The results concluded that the optimum pH for Cr(VI) and Cu (II) were 4 and 5, contact time: 360 min, adsorbent dosage: 4 g, and initial metal ion concentration: 100 mg/L for each metal ions. The adsorption isotherm models follow the Freundlich model and pseudo-second-order kinetics. From the results, the adsorption capacity was observed to be 80.43% for Cr(VI) and 82.47% for Cu(II) ions, respectively.