Spectroscopy Scanning Electron Research Articles

Synthesis & Characterization of Carbon Nanostructures.

Synthesis In this research a study was conducted on the Synthesis and dimensional structural characterization of nanostructures consisting of Graphene, Nanotubes and Fullerenes C60 and C70 carbon research project consists of a synthesis and characterization in its theoretical and experimental framework to test yields in the synthesis of each nanostructure. Synthesis for Multiple Synthesis Rector MSR will be held in the exploder and electric fields in the toroidal coil Tesla coil. As for the structural dimensional characterization of nanostructured materials carbon is carried out by Raman spectroscopy, diffraction X-ray (XRD) and Transmission Electron Microscopy (TEM) Scanning Electron Microscopy (SEM) Atomic Force Microscopy (AFM) and EELS (Energy Electron loss Spectrum). Justification Synthesis System The main justification synthesis system is to generate nanostructures (Nanotubes, Nanofibers, Fullerenes, graphene) easily and economically; all using little equipment and a simple process which is reflected in lower costs simple synthesis as current processes are very expensive and too complex. Justification Synthesis System The main objective of this system is the generation synthesis of nanostructures by using a Tesla coil (Plasma Generator) as the main component of the system being accessible, simple and inexpensive technology. Another goal is to optimize the generation of nanostructures to its widespread use in industry, nanotechnology and materials science. Through a system very inexpensive and simple synthesis.

Antioxidant and dye degradation activity of green synthesized silver-iron oxide (Ag-Fe2O3) bimetallic nanoparticles

This research introduces an eco-friendly method for synthesizing silver-iron oxide bimetallic nanoparticles using cabbage peel extract, serving as both reducing and stabilizing agents. The successful production of nanoparticles is comprehensively analyzed through UV-Vis spectroscopy, Fourier transformation infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The UV, XRD and EDS results indicated the elemental composition of Ag and Fe, suggesting the formation of a silver-core iron-shell bimetallic nanoparticles with a size of 22.3 nm, which was followed by an assessment of their antioxidant and catalytic properties. The findings revealed notable antioxidant capabilities, along with the efficient degradation of methyl red and phenol red dye. Remarkably, the Ag-Fe2O3 bimetallic nanoparticles exhibited good scavenging activity, reaching 63.87% at a concentration of 1000 µg/mL. The most significant dye degradation is observed for phenol red, achieving a remarkable 78% degradation within just 8 minutes. These results indicate the potential of Ag-Fe2O3 bimetallic nanoparticles derived from cabbage peels as promising agents for antioxidant and catalytic applications, especially in addressing dye-contaminated wastewater concerns.

Enhanced photocatalytic and antibacterial properties of silver–zirconia nanoparticles for environmental pollution treatment

Abstract Silver–zirconia nanoparticles (Ag–ZrO2 NPs) were synthesized via an in situ strategy at room temperature using NaBH4 as a reducing agent. The surface modification of ZrO2 nanoparticles with nano silver was confirmed through various characterization techniques including Fourier Transform Infrared Spectroscopy (FTIR), UV–vis Diffuse Reflectance Spectroscopy (UV–vis DRS), X-ray Diffraction (XRD), and Field Emission Scanning Electron Microscopy (FESEM). The obtained results demonstrated that Ag nanoparticles, with a crystallite size of approximately 12 nm, were uniformly distributed on the surface of ZrO2 nanoparticles. The incorporation of Ag nanoparticles to the ZrO2 nanoparticles led to increasing the light absorption ability and reducing the band gap of Ag–ZrO2 nanoparticles, thereby enhancing their photocatalytic performance under infrared lamp exposure. When 1 g/L of Ag–ZrO2 nanoparticles was employed to methylene blue (MB) solution, the degradation of MB reached 90 % after 5 h of exposure. Additionally, the Ag–ZrO2 nanoparticles exhibited a high antibacterial activity against two bacterial strains, E. coli and S. aureus. These findings highlight the potential of Ag–ZrO2 nanoparticles as effective materials for environmental pollution treatment through advanced oxidation processes.

Synthesis, characterization and biological applications of a new nano-sized binuclear copper(II) complex containing bathophenanthroline and ellagic acid as ligands

A new binuclear copper(II) complex, nano-[Cu2-(DIP)2-EA], was synthesized by using bathophenanthroline and ellagic acid ligands in a multi-component/one-pot method, and then characterized by electrospray ionization mass spectrometry (ESI-MS), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectrophotometry (UV–vis), thermogravimetric analysis (TGA), and field emission scanning electron microscopy (FE-SEM). The antioxidant, antibacterial, and anticancer properties of the synthesized nano-[Cu2-(DIP)2-EA] were studied. The DPPH radical test pointed out that the nano-[Cu2-(DIP)2-EA] enjoys a good potential (28.4 %) to scavenge free radicals and the bacteria culture indicated a moderate ability of the complex to prevent the growth and proliferation of gram-positive bacteria (Staphylococcus aureus ATCC 29,213) and gram-negative ones (Pseudomonas aeruginosa ATCC 27,853). The cell culture displayed a superior ability of nano-[Cu2-(DIP)2-EA] to destroy breast cancer cells (MCF-7) compared to ellagic acid. In addition, the binding interaction of nano-[Cu2-(DIP)2-EA] with ct-DNA was studied in vitro (pH 7.40) by ultraviolet-visible absorption spectrophotometry, fluorescence emission spectrofluorimetry, circular dichroism (CD) spectropolarimetry, viscosity assessment technique, and molecular docking computer simulation. The results of the fluorescence enhancement spectra clearly showed a desirable affinity of nano-[Cu2-(DIP)2-EA] to ct-DNA. A hyperchromic effect was observed along with a slight red shift in the UV-visible spectra of nano-[Cu2-(DIP)2-EA]-DNA adduct, indicating that the nano-[Cu2-(DIP)2-EA] can form a conjugate with ct-DNA molecule. Thermodynamic properties exhibited an exothermic spontaneous formation of nano-[Cu2-(DIP)2-EA]-DNA adduct favored by H-bonds and van der Waals forces. The competitive emission investigations using methylene blue (MB) and Hoechst 33,258 demonstrated that the binuclear copper(II) can replace the DNA-bound Hoechst and interact via minor grooves, as confirmed also by negligible viscosity alterations. The CD observations proposed that the nano-[Cu2-(DIP)2-EA] induces conformational changes in the ct-DNA. Molecular docking modeling results recognized a minor groove mechanism of nano-[Cu2-(DIP)2-EA] to interact with ct-DNA, and the complexation process is supported by H-bonds and van der Waals interactions.

Modification of Agro-wastes Reinforced onto the PET Fabric for Decolorisation of Palm Oil Mill Effluent

The abundance of agricultural wastes from various industrialized processes has become one of the significant contributors to water pollution, particularly in the color of effluents from industrial-based palm oil mills. Inventively, this research focused on three different agro-wastes: pineapple leaves (PL), rice straw (RS), and empty fruit bunch (EFB) reinforced onto PET fabric composite and its decolorization performances by using palm oil mill final effluent discharged (POME-FED). The calcinated agro wastes/polyvinylidene fluoride (PVDF) reinforced onto the polyethylene terephthalate (PET) fabrics were prepared by using the dip-coating technique and characterized via Scanning Electron Microscopy (SEM-EDS), spectroscopy (FTIR-ATR), turbidity and color of POME-FED. It was found that the calcinated PL/PVDF/Fabric displayed the best performance in the turbidity and decolorization by 12.02 NTU, 760 ADMI, and ~60% color removal efficiency as compared with raw POME-FED (~1800 ADMI). Nevertheless, the decolorization efficiencies of RS/PVDF/Fabric and EFB/PVDF/Fabric had increased by ~37 % and ~49 %, respectively. It shows that the formation of a reinforcing layer on the PET fabric surface has improved the transparency of POME-FED. The SEM micrographs and the change of peaks at regions 1650 cm-1, 1450 cm-1, 1210 cm-1, and 990 cm-1 in composites' spectroscopies demonstrate the different patterns of these calcinated samples are various patterns that impart the strength of the composite fabric surface functionality and hydrophobicity. The reduction of the color value of effluent showed the hydrophobicity of the integrated palm oil waste coated with PET, which enables to trap of the particles in the effluent, thus this composite has potential use in the filtration of water treatment.

Effect of cerium oxide nanorods growth time on the electrochromic properties of WO3/CeO2 hybrid films

In this study, the cerium oxide nanorods (CeO2) were grown on fluorine-doped tin oxide (FTO) glass substrates by using a hydrothermal process at growth times of 4hrs, 6hrs and 12hrs and annealed at temperature 3500C. The grown samples were characterized by using Scanning electron spectroscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Raman spectroscopy, and UV–Vis spectrometer. Tungsten oxide (WO3) film was deposited, on these hydrothermally grown nanorods (NRs), by using the DC sputtering process to develop WO3/CeO2 hybrid films. From the SEM and XRD analysis, CeO2 nanorods were observed at different growth times, and crystalline structures were observed respectively. The optical transmittance decreases with the increase in synthesis time, mainly due to the increase in nanorods' thickness. The diffusion coefficient of 11.24 × 10−11 cm2/s and the cathodic peak current of −10.1 mA was observed for 12-h WO3/CeO2 films and the coloration efficiency of 12 cm2/C was observed for 4-h WO3/CeO2 hybrid film.

Green synthesis of solketal from glycerol using metal-modified ZSM-5 zeolite catalysts: process optimization.

This study investigates the production of solketal (2,2-dimethyl-1,3-dioxolane-4-methanol) from glycerol via ketalization reaction using M-ZSM-5 catalysts (M = Fe, Co, Ni, Cu, and Zn). The wet impregnation method ensured precise metal loading and versatility in catalyst preparation. We present a novel approach by employing a suite of characterization techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), Thermogravimetric analysis (TGA), and Field-emission scanning electron microscopy (FE-SEM), to elucidate the catalyst's structure, bonding, surface area, thermal stability, and morphology, ultimately linking these properties to their performance. Solketal synthesis was optimized in a reactor, with parameters like temperature, glycerol:acetone molar ratio, catalyst amount, reaction time, and stirring speed. Optimal conditions were identified as 60°C, 1:4, 0.2g, 60min, and 1200rpm, respectively. Gas chromatography-mass spectrometry (GC-MS) analysis confirmed successful solketal formation. Among M-ZSM-5 catalysts tested, Cu-ZSM-5 emerged the most efficient, achieving an impressive 99% glycerol conversion and 96% solketal selectivity. Notably, Cu-ZSM-5 catalyst displayed exceptional reusability, regaining its initial activity through calcination, thus minimizing waste generation. This research unveils Cu-ZSM-5 as a highly efficient catalyst and promotes sustainability by utilizing a renewable glycerol feedstock to produce valuable solketal with applications in fuel additives, solvents, and pharmaceuticals. This work paves the way for developing environmentally friendly processes for waste valorization and producing valuable bio-based chemicals.

Amine functionalized graphene oxide decorated with ZnO-WO3 nanocomposites for remediation of organic dye from wastewater

Photocatalytic degradation is as an efficient technique to eradicate toxic chemical pollutants from contaminated water sources. However, the selectivity and photocatalytic activity are the challenging targets to explore the new photocatalysts. Therefore, our research goal is to develop a suitable photocatalyst to satisfy the recent photocatalytic degradation demand. In this work, amine functionalized graphene oxide (NH2-GO) supported heterojunction ternary novel nanocomposites (NH2-GO/ZnO-WO3) were prepared via simple solvothermal method. Structural and morphological investigations of the prepared composites are systematically observed by Field Emission Scanning Electron Spectroscopy (FE-SEM), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), and Ultraviolet–Visible (UV–vis) Spectroscopy. FT-IR analysis confirmed the effective functionalization of amine on graphene oxide. The XRD results indicated that the prepared nanocomposites were free from any impurities and the binary composite (NH2-GO/ZnO) showed hexagonal wurtzite structure, whereas the ternary composite (NH2-GO/ZnO-WO3) exhibited mix crystal structure of monoclinic and hexagonal phase of WO3 and ZnO, respectively. The synthesized ternary photocatalyst (NH2-GO/ZnO-WO3) demonstrated superior photocatalytic efficiency towards various organic dyes such as cationic dye methylene blue (MB, 85.89%) and anionic dye methyl orange (MO, 60.98%) compared to binary photocatalyst (NH2-GO/ZnO) that showed only 52.28% of MB and 25.8% of MO dye degradation under UV light irradiation. The enhanced photocatalytic performance was mainly due to the low recombination rate of photogenerated electron-hole pair, narrow band gap, and large surface area of ternary composite. The presence of lone pair electrons in amino group provides a negative-charged surface composite resulting good interaction with cationic dye is the key to upgrade the photocatalytic performance. The ternary nanocomposite NH2-GO/ZnO-WO3 has the capacity to be a competent and acceptable photocatalyst for the photodegradation of organic dyes used in industries.

Elucidation of enhanced cellulase immobilization onto synthetic magnetic nickel nanomaterials for lignocellulosic biomass hydrolysis

The immobilization of cellulase enzymes for the conversion of lignocellulosic biomass into sustainable biochemical products is essential for the stability and recovery of the enzymes. In this study, nickel nanoparticles (NiNPs) were synthesized and coated with 3-aminopropyl triethoxysilane (APTES) to serve as cellulase enzyme carriers. Cellulase enzyme immobilization on the prepared NiNPs was achieved using glutaraldehyde as a cross-linker. The physicochemical properties of the carrier were determined before and after enzyme immobilization using X-ray Powder Diffraction (XRD), Transmission Electron Microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Vibrating-Sample Magnetometer (VSM), and Field Emission Scanning Electron Microscopy (FESEM). The impacts of different experimental factors on the performance of the cellulase enzymes immobilized on the synthesized NiNPs and commercial nickel nanoparticles were compared. The results showed comparable optimal cellulase enzyme immobilization conditions on both substrates in terms of the immobilization time, pH, and cellulase enzyme concentration. However, the recommended temperatures for cellulase enzyme immobilization on the synthesized and commercial NiNPs were 50 °C and 40 °C, respectively. Under these optimum conditions, the immobilized cellulase enzyme on the synthesized NiNPs had an activity of about 99.1% (in comparison to the activity of free cellulase enzyme), while the activity of the enzyme upon immobilization on commercial NiNPs was about 93%. The particle size of the NiNPs was found to be crucial for enzyme immobilization efficiency and its magnetic strength. Therefore, cellulase enzyme immobilization on tunable NiNPs could be a sustainable and eco-friendly approach towards high recovery of cellulose from lignocellulosic materials.

Ultrasound-Driven Deposition of Au and Ag Nanoparticles on Citrus Pectin: Preparation and Characterisation of Antimicrobial Composites.

Pectin is a renewable, non-toxic and biodegradable polymer made of galacturonic acid units. Its polar groups make it suitable for complexing and supporting metallic nanoparticles (NPs). This work aimed to produce antibacterial nanocomposites using pectin and acoustic cavitation. The metal NPs (Au or Ag) were deposited using ultrasound (US, 21 kHz, 50 W) and compared with those achieved with mechanical stirring. The impact of the reducing agents (NaBH4, ascorbic acid) on the dispersion and morphology of the resulting NPs was also assessed. Characterization by diffuse reflectance (DR) UV-Vis-NIR spectroscopy and field emission scanning electron microscopy (FESEM) showed that the use of US improves the dispersion and decreases the size of both Au and Ag NPs. Moreover, with Au NPs, avoiding external reductants led to smaller NPs and more uniform in size. The prepared NPs were functionalized with oxytetracycline in water and tested against Escherichia coli (gram negative) and Staphylococcus epidermidis (gram positive) via the Kirby-Bauer test. The results show a better antibacterial activity of the functionalized nanoparticles compared to antibiotic-free NPs and pure oxytetracycline, advising the potential of the nanoparticles as drug carriers. These findings underscore the significance of US-assisted synthesis, paving the way to new environmentally friendly antimicrobial materials.

Preparation of the novel bio‐nanocomposites based on chitosan, Piper betle leaf extract and MgO nanoparticles for chili preservation

AbstractTo maintain the freshness of food, it is crucial to explore environmentally friendly preservation methods with a focus on safety. Chitosan, a natural coating for fruits, is often used in combination with other materials to enhance its ability to delay browning and prevent fungal diseases. This study focused on the synthesis of a novel chitosan‐based nanocomposite by incorporating Piper betle L. leaf extract (PE) and magnesium oxide nanoparticles (MNPs). The characteristics of the obtained products were analyzed using infrared spectroscopy, x‐ray diffraction, and field emission scanning electron microscopy (FESEM). The mechanical strength of chitosan/PE/MNPs (CSTM) films was evaluated, and the uniformity of the CSTM films was assessed using optical microscopy and FESEM. The antibacterial activity of CSTM films against Staphylococcus aureus and Escherichia coli was tested using the diffusion method on agar wells. Additionally, the swelling behavior of CSTM films was measured. The findings demonstrated that these CSTM films exhibited resistance to S. aureus, making them potentially efficient for chili preservation.

Effect of chemical oxidation process on adhesive performance in two component adhesive with nano particle and nano fiber additives

In the present study, chemically surface-treated nanoparticles and nanofibers were added to the adhesive to improve the performance of the two-component structural adhesive. In the study, DP460 structural adhesive was used as adhesive, functionalized Multi Walled Carbon Nanotubes (MWCNT-COOH) with COOH and carbon fiber (CF) chemically surface treated with HNO3 solution were used as nanostructures. In the experimental study, eight different parameters were investigated as the nanostructure was (i) undoped, (ii) 1 wt% MWCNT-COOH added, (iii) 1wt%. untreated CF added, (iv) 0.5 wt% chemically treated CF added, (v) 1 wt% chemically treated CF added, (vi) 2 wt% chemically treated CF added, (vii) 0.5 wt% MWCNT-COOH and 0.5 wt% chemically treated CF added, and (viii) 1 wt% MWCNT-COOH and 1wt% chemically treated CF added. According to the results of the study, adding nanoparticles to the adhesive increases the performance of the adhesive by about 12%, while adding nanofibers increases the performance of the adhesive by about 18%. In addition, increasing the inertness and wettability of nanofibers by chemical treatment, as well as the use of nanoparticles and fibers together, significantly increases the performance of the adhesive. In addition, the obtained results were supported by fourier transform infrared spectroscopy (FT-IR) analysis and scanning electron microscopic (SEM) analysis.

The Lawson-loaded β-cyclodextrin nanocarriers (LB-NCs) a novel targeted cancer cell in stomach and breast cancer as a drug delivery system.

Applying nanotechnology to design drug delivery systems is a promising turning point in cancer treatment strategies. In the current study, Lawson, a nonpolar anticancer phytochemical, was entrapped into β-cyclodextrin polymer to evaluate its selective cytotoxicity in several types of human cancer cell lines including MCF-7, AGS, A549, and PC3. The Lawson-loaded β-cyclodextrin nanocarriers (LB-NCs) were produced by applying a high-energy ultrasound-mediated homogenization technique. The LB-NCs were characterized by applying dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), zeta potential, and field emission scanning electron microscopy (FESEM) analysis. Also, the selective cytotoxic impact of the LB-NCs was studied by conducting the MTT assay on human MCF-7, AGS, A549, and PC3 cancer cell lines. Finally, the type of cellular death was evaluated by measuring the cell cycle status and apoptotic gene expression profile of the treated MCF-7 cells by conducting flow cytometry and Q-PCR methods, respectively. The synthesized negatively charged (- 23.8 mV) nanoparticles (348.12 nm) exhibited apoptotic activity in the human breast MCF-7 cancer cells by upregulating the apoptotic gene expression profile (Caspase 3, 8, and 9). The LB-NCs exhibited a significant selective cytotoxic effect on the human cancer cell lines compared with the normal HUVEC cells. However, variable toxic intensities were detected depending on the cancer cell type. Selective cancer cell-depended anticancer activity of the produced LB-NCs has the potential to be considered their safe efficient targeted anticancer activity. However, studying the animal cancer models has to be conducted to verify their selective toxicity and clarify the cellular death mechanism.

Adsorptive removal of heavy metal ions from aqueous solution by using green synthesized copper oxide nanoparticles

Metal nanoparticles can be synthesized by “green synthesis” methods, an efficient and environmentally friendly process that involves combination of metal salt solution with plant extract. Due to low cost, ideal surface area, plenty of active sites, and high adsorption capabilities, copper oxide nanoparticles (CuO-NPs) have drawn a lot of attention as effective adsorbents. Our present study is primarily concerned about green synthesis route of producing copper oxide nanoparticles (CuO-NPs) from flower extract of Nyctanthesarbor-tristis. The prepared CuO-NPs was used in the adsorption of toxic metal ions including U(VI), Pb(II), Cr(VI), and Cd(II) from water samples was studied. Different analytical techniques like UV-visible spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy and field emission scanning electron microscopy has been used for analyzing the properties of prepared copper oxide nanoparticles. A batch experiment has also been conducted to determine the efficacy of the synthesized copper oxide nanoparticles toward the adsorption of toxic metal ions including U(VI), Pb(II), Cr(VI), and Cd(II) from water samples at various parameters, such as the impact of pH, contact time and adsorbent dosage. According to the results, the adsorption capacity (qmax) of CuO-NPs for U(VI), Pb(II), Cr(VI), and Cd(II) metal ions are 200, 155.27, 131.57 and 90.90 respectively. The kinetic studies showed that the pseudo-second order kinetics model has best fits to the data (R2= 0.85, 0.91, 0.89, 0.92 for U(VI), Pb(II), Cr(VI), and Cd(II) respectively. The study also included pseudo-first order, Elovich models and intra particle diffusion. In light of these findings, copper oxide nanoparticles were found to be a promising nano-adsorbent for the treatment of water.

Fundamental characteristics of biomimetic superhydrophobic surface of nitinol alloy fabricated via laser cauterization and FAS modification

Biomimetic superhydrophobic surfaces draw inspiration from the biological realm, seeking to replicate and refine their superhydrophobic properties. Fabricating super-hydrophobic surface on nitinol has significant application value in medicine, biomedical science, industry, and micro electric system due to the special performance of this material with super-hydrophobicity. In this study, we achieved a super-hydrophobic surface on a laser-processed rough nitinol surface through FAS modification, and its corrosion resistance in salt electrolytes was evaluated using potentiodyjnamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) measurements. The resulting indicated that the fabricated super-hydrophobic surface exhibited superior corrosion resistance performance. Besides, the mechanical properties of the material were also evaluated, revealing a reduction in contact angle by 2.04 and 2.82 times as well as enhanced wear its resistance. Furthermore, the promoting mechanism of chemical and abrasion stability were systematically elucidated based on scanning electron spectroscopy (SEM-EDS), 3D optical profiling, and X-ray photoelectron spectroscopy (XPS). These findings are anticipated to provide a deeper understanding of the fabrication of super-hydrophobic surfaces on nitinol alloys, thereby strengthening their potential for practical industrial and biomedical applications.

Preparation of Metal - Organic Framework MIL-88B(Fe)-NH<sub>2</sub> for Efficient Adsorption of Congo Red in Aqueous Environment

MIL-88B(Fe)-NH2 material was prepared by a simple solvothermal method. Various techniques were performed to investigate material characteristics including X-ray diffraction (XRD), scanning electron spectroscopy (SEM), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) surface area. The result indicates that the particle shape is a bipyramidal hexagonal prism having a porous surface, and the BET surface area is 13.43 m2/g. Adsorption of congo red (CR) onto MIL-88B(Fe)-NH2 was studied as well. The adsorption equilibrium of the material is reached rapidly after 10 minutes with excellent adsorption efficiency (98.02%). Adsorption kinetic conforms to Langmuir isothermal adsorption model with the high maximum capacity of 333.33 mg/g.

Facile encapsulation of cyanoacrylate-based bioadhesive by electrospray method and investigation of the process parameters

Polymer microcapsules containing cyanoacrylates have represented a promising option to develop self-healing biomaterials. This study aims to develop an electrospray method for the preparation of capsules using poly(methyl methacrylate) (PMMA) as the encapsulant and ethyl 2-cyanoacrylate (EC) as the encapsulate. It also aims to study the effect of the electrospray process parameters on the size and morphology of the capsules. The capsules were characterized using Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and field-emission scanning electron microscopy (FE-SEM). Moreover, the effects of electrospray process parameters on the size were investigated by Taguchi experimental design. FTIR and TGA approved the presence of both PMMA and EC without further reaction. FE-SEM micrograph demonstrated that an appropriate choice of solvents, utilizing an appropriate PMMA:EC ratio and sufficient PMMA concentration are critical factors to produce capsules dominantly with an intact and spherical morphology. Utilizing various flow rates (0.3–0.5 ml/h) and applied voltage (18–26 kV), capsules were obtained with a 600–1000 nm size range. At constantly applied voltages, the increase in flow rate increased the capsule size up to 40% (ANOVA, p ≤ 0.05), while at constant flow rates, the increase in applied voltage reduced the average capsule size by 3.4–26% (ANOVA, p ≤ 0.05). The results from the Taguchi design represented the significance of solution flow rate, applied voltage, and solution concentration. It was shown that the most effective parameter on the size of capsules is flow rate. This research demonstrated that electrospray can be utilized as a convenient method for the preparation of sub-micron PMMA capsules containing EC. Furthermore, the morphology of the capsules is dominated by solvents, PMMA concentration, and PMMA:EC ratio, while the average size of the capsules can be altered by adjusting the flow rate and applied voltage of the electrospray process.

An Eco-friendly Mangifera indica Leaves Extract Corrosion Inhibitor for Stainless Steel in Acidic Medium

Corrosion of metals and alloys is one of the most frequent problems encountered in chemical and process industries. Inefficient corrosion control measures typically lead to an increased risk of unplanned downtime, huge economic loss, environmental damage, and health and safety hazards. Hence, it is essential to develop environment-friendly and cost-effective corrosion inhibitors over existing toxic anticorrosive agents. The main objective of this work is to examine the efficacy of eco-friendly ethanolic extract of Mangifera indica leaves (MIL) in different concentrations as a green corrosion inhibitor for stainless steel (SS-316L) under an acidic environment. The inhibition efficiency of Mangifera indica leaves extract in 1 M hydrochloric acid (HCl) was evaluated by conventional weight loss method along with adsorption isotherm analysis. Chemical compounds present in leaf extract and changes in surface morphology of SS-316L samples were assessed using Fourier Transform Infrared spectroscopy (FTIR) and Field Emission Scanning Electron Microscopy (FE-SEM) provided with elemental analysis. The results of the weight loss method revealed that the inhibition efficiency increases with increasing MIL extract concentration due to higher surface coverage. The highest inhibition efficiency of almost 63.43% in 14 days and minimum corrosion rate of 0.433 mm per year was obtained for SS-316 L in 1.0 M HCl with 1000 ppm concentration. The adsorption of MIL extract on SS-316L surface followed Freundlich adsorption isotherm, and the obtained value of free Energy of adsorption (ΔG˚ads = – 9.20 kJ.mol-1) indicates the physical adsorption mechanism. The developed regression-based models can predict the corrosion rate as a function of inhibitor concentration and exposure time with good accuracy (>80%). Thus, the present findings demonstrate that Mangifera indica L. leaves extract can suitably be applied as an inexpensive, non-toxic, biodegradable, efficient green corrosion inhibitor for the protection of stainless steel in acidic media.

Electrochemical and corrosion protection performance of Sr-HaP/PoPD coated LN stainless steel

BackgroundStainless steel is a common implant material used in orthopaedic surgeries. However, metallic ions are released from the implants when it placed inside the human body. Coating of biocompatible material such as strontium hydroxyapatite (Sr-HaP) is one of the methods to reduce the release of metallic ions into the body. MethodIn the present work, we have developed a bilayer coating namely poly-orthophenylenediamine (PoPD) on Sr-HaP deposited low nickel stainless steel (LNSS) via electrochemical deposition followed by electropolymerization methods. The Sr-HaP/PoPD coating was confirmed with Fourier transform infrared spectroscopy (FTIR) and high resolution scanning electron microscopy (HR-SEM). The corrosion protection performance of the coated LN SS specimens in Ringer's solution was investigated using potentiodynamic polarisation and electrochemical impedance spectroscopic techniques. The leach out characteristics of the coating was determined at the impressed potential. Significant findingsThe studies revealed that the passive film underneath the PoPD layer is acting like a shield and prevent the LN SS from corrosion. Furthermore, the potential bioactivity of LN SS is due to the presence of top porous Sr-HaP layer. Hence, the PoPD/Sr-HaP bilayer coating on LN SS substrate could be a promising material for orthopaedic implant applications.

Development of highly sensitive electrochemical immunosensor using PPy-MoS2-based nanocomposites modified with 90MeV C6+ ion beams.

Theevaluation of electrochemical sensing activity of hydrothermally derived PPy-MoS2-based nanocomposites subjected to 90MeV C6+ ion beam with fluence ranging, 1.0 × 1010-1.0 × 1013 ions/cm2, is reported. Cross-linking, chain scissioning, and ion track formation could occur in the irradiated systems, as revealed from Fourier transform infrared (FTIR) spectroscopy and field emission scanning electron microscopy (FE-SEM)studies. Electrochemical studies, viz., cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were performed in 0.1M phosphate buffer solution (PBS) containing 5mM K3[Fe(CN)6] as redox probe. High redox activity, lower charge transfer resistance (Rct = 490 Ω) and larger electroactive area (A = 0.4485 cm2) were obtained in case of the composite system irradiated with a fluence of 3.5 × 1011 ions/cm2. Immunosensor fabrication was executed via immobilization of mouse IgG over the pristine and post-irradiated electrodes. Afterwards, differential pulse voltammetry (DPV) was performed within thepotential window - 0.2 to + 0.6V (vs. Ag/AgCl) for the detection of specific analyte. Noticeably, the electrode system irradiated with a fluence of 3.5 × 1011 ions/cm2 ischaracterized by a lower limit of detection (LOD) of 0.203nM and a higher sensitivity value of 10.0 µAmLng-1cm-2. The energetic particle irradiation at a modest fluence can offer beneficial effects to thePPy-MoS2-based nanohybrid system providing immense scope as advanced electrochemical biosensor.