Scanning Electron Microscopy-electron Dispersive Spectroscopy Research Articles

Evaluation of adsorption behaviour of benzylidene chitosan derivatives at mild steel/ 0.5 M H2SO4 solution interface

Four green benzylidene chitosan derivatives (BCs) were synthesized and evaluated as anti-corrosive substances for the first time against mild steel corrosion in 0.5 M H2SO4 solution. The synthesized BCs were laid to infrared spectroscopy and proton resonance spectroscopy for structural confirmation. Gravimetric and electrochemical experiments were accustomed to appraise the effectiveness of inhibitors, however, Scanning Electron Microscopy-Electron Dispersive Spectroscopy (SEM-EDS), Atomic Force Microscopy (AFM), and X-ray Photoelectron Spectroscopy (XPS) were exploited to evaluate the protective mechanism offered by benzylidene chitosan derivatives. Experimental results demarcate the synthesized inhibitors; Anisaldehyde modified Chitosan (CMB), 2-Hydroxy-4-methoxybenzaldehyde modified Chitosan (CHMB), 2,4-Dimethoxybenzaldehyde modified Chitosan (CDMB) and 2-Bromo-4-methoxybenzaldehyde modified Chitosan (CBMB) exhibiting praising inhibitory properties for mild steel corrosion and CDMB was seen possessed preferable inhibition potential at the finest concentration of 500 mgL-1 owing to the proximity of two electron-donating OCH3 groups. Furthermore, the inhibitors have been recorded to behave mixed type with pronounced impact on hydrogen evolution kinetics. The order of inhibition efficacy obtained was CDMB (98.8 %) > CHMB (95.4 %) > CMB (92.8 %) > CBMB (89.2 %) which was further validated by quantum chemical calculations which later opened up about the mechanistic approach involved in electron transfer from inhibitors to metallic vacant orbitals. Additionally, the effect of molecular structure possessed by synthesized inhibitors has been correlated with observed variation in their corrosion inhibition efficiency.

High-Temperature Wear and Frictional Performance of Plasma-Nitrided AISI H13 Die Steel

Plasma nitriding, a surface treatment technique, is gaining popularity, as it is environment-friendly and offers superior mechanical properties. This research studied the wear and friction performance of AISI H13 die steel after plasma nitriding in a gas mixture of N2:H2 at 20:80, 50:50, and 80:20 (volume ratio) at a fixed time and temperature. This work aimed to analyze the sliding wear performance of the plasma-nitrided tool die steel in hot-forming operations at higher loads. Scanning electron microscopy/electron-dispersive spectroscopy (SEM/EDS) and X-ray diffraction (XRD) techniques were used to study the microstructures of the H13 die steel pins after plasma nitriding. Wear tests were performed on a high-temperature tribometer under uni-directional sliding and dry conditions using a high-temperature tribometer under a 50 N load at various operating temperatures ranging from 25 °C to 600 °C. The results show that the plasma-nitriding process with N2:H2 at 20:80 improved the wear behavior of H13 steel. The friction coefficients and wear volume losses for all the plasma-nitrided specimens were less than those of the untreated die steel.

Silver/selenium/chitosan co‐substituted bioceramic coatings of Ni–Ti alloy: Antibacterial efficiency and cell viability

The effects of silver (Ag), selenium (Se), and chitosan (Cht) additives on the antibacterial activity and cell viability of NiTi were investigated. Three different hydroxyapatite (HA)-based bioceramic coatings to improve the antibacterial activity and cell viability of NiTi; HA, HA/Ag, and HA/Se–Cht were applied to NiTi substrates by a sol–gel method. The coated samples were characterized by scanning electron microscopy–electron-dispersive spectroscopy and X-ray diffraction and surface hardnesses were measured. The antimicrobial efficiency of the coatings and uncoated surfaces were tested against Escherichia coli-JM 103 and Staphylococcus aureus-ATCC29293. In vitro cell–material interactions using Saos-2 osteoblast cells were characterized by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (mitochondrial activity test) assay for cell viability. A homogeneous, crack-free, and porous surface morphology is achieved in coatings. It has been shown that the Se–Cht additives did not have a significant effect on the surface hardness of the HA coating, but the Ag additive increased the hardness. Through in vitro antibacterial activity and cell viability tests, it was shown that Ag additive to bioceramic coatings significantly increased (p < .05) antibacterial properties but caused a decrease in cell viability. However, although Se–Cht additives did not have a significant effect on antibacterial properties (p < .05), it was observed that they increased cell viability.

High-Performance and Functional Fiber Materials—A Review of Properties, Scanning Electron Microscopy SEM and Electron Dispersive Spectroscopy EDS

This review supports an overview of selected high-performance fibers and functional fiber materials. A review of several properties and applications is given. For fiber materials and fabrics, microscopic images taken by scanning electron microscopy (SEM) are presented. As well as this, electron dispersive spectroscopy (EDS) is performed on the fiber materials and an overview of EDS spectra is presented. The features of SEM images and EDS spectra are discussed, especially with the aim of supporting people who are working in the field of fiber analytics. To support a complete view of both analytic methods—SEM and EDS—challenges and typical mistakes for SEM measurements on textiles are also described. Altogether, this review supports a useful overview of interesting high technology fiber materials and their investigation using the analytical methods SEM and EDS. Using these, material properties and their composition are presented and discussed. The composition of industrial fiber materials is investigated and discussed, as well as fiber treatments for the realization of functional fiber properties. Furthermore, it aims to support a helpful tool for fiber and textile analytics and identification.

PALM SHELL-DERIVED ACTIVATED CARBON ADSORBENT IS BETTER THAN THAT OF COCONUT SHELL: COMPARATIVE STUDIES OF COD ADSORPTION FROM PALM OIL MILL EFFLUENT

Palm and coconut shells are among the most common feed materials for activated carbon manufacturing. Activated carbon is an excellent adsorbent for palm oil mill effluent (POME), especially for the removal of chemical oxygen demand (COD). Palm shell-based activated carbon (PAC) and coconut shell-based activated carbon (CAC) have been prepared through carbonization and followed by an activation process using H2SO4 2.5 M. Both PAC and CAC have lower contents of moisture, fly ash, and ash than that of Indonesian national standard thresholds. The COD removal from POME was performed with the batch adsorption method, where it reached adsorption saturation after 45 minutes of stirring time and optimum removal at pH 3. Isotherm studies suggest that the COD removal using PAC and CAC fit the theoretical data from the Langmuir isotherm model (R2 &gt; 0.99) with Qm of 854.701 and 826.446 mg/g, respectively. The investigation also indicates that PAC has a better performance in COD removal, which has been justified by the elucidation using Fourier Transform-Infrared (FT-IR) and Scanning Electron Microscopy – Electron Dispersive Spectroscopy (SEM-EDS) technique.

Artificial Inclusion Environments—Replicating Industry in the Laboratory

The authors present a series of complementary test methods which were developed and used to investigate reactions between high aluminium steel and silica rich inclusions. Non-metallic inclusions (NMIs) cause many defects in the final steel product, therefore the ability to track their size, morphology and composition and correlate this with fundamental reaction kinetics provides important knowledge to support the production of clean quality steel products. Novel steel grades such as TRIP, TWIP and low-density steels have high aluminium contents; aluminium is a readily oxidisable species presenting the potential for instability and excessive reaction with commonly used mould powders that contain silica. A novel combination of techniques including HT-CLSM (High-Temperature Confocal Laser Scanning Microscope), XCT (X-ray computed tomography) and SEM/EDS (scanning electron microscopy/electron dispersive spectroscopy) have been used to study the interaction of entrained mould powder inclusions with steel at high temperatures simulating industrial conditions. This report presents a discussion on the development of techniques and samples to achieve representative and repeatable results that can provide information on the complex chemical and physical interaction phenomena with confidence. Each experimental technique had its own learning points and consequent results. Outcomes presented include possible confirmation of the chemical reaction rate controlling step being aluminium mass transfer; heterogeneous local environmental conditions including fluidity and chemical composition; and occurrence of spontaneous emulsification where the mould powder inclusion breaks apart into a cloud of smaller fragments.

Improvement of Waste Metal Recovery Efficiency Using Multivariate Statistical and Deep Neural Network Analysis

In this study, we collected spectral data using laser induced breakdown spectrometry. Our results were processed by a principle component analysis (PCA) and a deep neural network to improve the separation efficiency of metals from RAM samples of a printed circuit board (PCB). The spectra were collected from 294 spots on the sample surface and subsequently divided into three groups, i.e., Black (K), Yellow (Y), and Green (G) by visual inspection of the surface color. We identified the specific wavelengths that were usable as separation criteria as well as the main elemental composition of each part by comparing the PCA and scanning electron microscopy-electron dispersive spectroscopy results. We also confirmed the possibility of automatic separation with a deep neural network whose separation accuracy was more than 98%. Our results can be used to create a new automatic separation process for waste electronic electrical equipment.

Surface Modification of Jute Fabric by Treating with Silane Coupling Agent for Reducing Its Moisture Regain Characteristics

ABSTRACT In the present study, the effect of silane treatment method on reducing the moisture regain of the jute fabric was investigated. Triethoxyvinylsilane, a widely used hydrophobic silane is used as the silane coupling agent. The treated fabrics were characterized by Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy/Electron dispersive spectroscopy (SEM/EDS) and for contact angle, moisture regain etc. It was observed that the moisture regain of the jute fabric reduced significantly by this treatment. The contact angle measurement showed that after silane treatment, the surface of the jute fabric became exclusively hydrophobic in nature with a contact angle of 111°. FTIR analysis of the treated fabric showed the presence of Si-O-C linkage on the surface which confirms that the hydroxyl groups of the jute fabric react with the silanol molecules forming Si-O-C linkages. The grafting of silane molecules onto the surface of jute fabric was further confirmed by the presence of silicone atoms detected by electron dispersive spectroscopy. It is expected that the findings of the work will open up new horizons for utilization of jute fabric in the area of healthcare, oil absorbent mat, composites and geo-textiles.

Biocompatibility and osteogenic activity of guided bone regeneration membrane based on chitosan-coated magnesium alloy

Ideally, a guided bone regeneration membrane (GBRM) should possess high strength, as for titanium membranes, along with excellent biocompatibility and osteoconductivity, as for natural absorbable collagen membranes. Besides titanium, magnesium (Mg) is another metal widely used in the biomedical field, which also exhibits biodegradability. In this study, a composite chitosan‑magnesium (CS-Mg) membrane was fabricated by dip-coating Mg alloy into chitosan solution. In vitro and in vivo tests were performed to investigate whether this membrane could be used as biodegradable GBRM, and the test results were compared with those obtained for a commercial GBRM (Heal-All). The microstructure was analyzed by scanning electron microscopy-electron dispersive spectroscopy. The degradation behavior was investigated by immersing the membranes into Dulbecco's modified Eagle medium (DMEM). The in vitro biocompatibility was evaluated by cell adhesion, cytotoxicity and alkaline phosphatase (ALP) assays using MG63 cells. The cytotoxicity and ALP assays were performed with diluted extracts of Mg, CS-Mg and Heal-All. The results show that CS-Mg has a suitable degradation rate, as well as similar cell adhesion and cytocompatibility to Heal-All. However, the 10% CS-Mg extracts exhibited higher ALP activity at 3 and 5 days (p < 0.05) compared with the medium control and the Heal-All extracts, but no differences with 10% Mg extracts (p > 0.05). Rabbit calvarial defects were used for testing the osteogenic activity in vivo. Three groups of samples were examined: CS-Mg, Heal-All, and a blank control. Higher amounts of new bone were formed for the CS-Mg and Heal-All groups (p < 0.05) compared with the blank control, whereas no significant differences between the CS-Mg and Heal-All groups were observed (p > 0.1). In conclusion, the CS-Mg membrane shows great potential for application as a biodegradable metallic GBRM with excellent osteogenic activity.

The effect of partial substitution of monovalent ion on divalent ion of La0.8Ca0.2-xAgxMnO3 (x=0 and x=0.05) compounds in structure, morphology, and purity by sol-gel method

La0.8Ca0.2-xAgxMnO3 ceramics with x = 0 and 0.05 has been synthesized using the sol gel method. These materials are one member of perovskite manganites materials which has the general formula RE1-xAExMnO3. Material LaCaMnO3 and La0.8Ca0.15Ag0.05MnO3 was characterized by X-ray Diffractometer (XRD), and Scanning Electron Microscopy-Electron Dispersive Spectroscopy (SEM-EDS). According to X-Ray Diffractometer characterization and high score refinement showed that the crystal structure for both materials are orthorhombic. Partial substitution of the Ag+ in Ca2+ did not change the structure of the material but there are changes in lattice parameters. Both materials have a high homogeneity with the larger crystallite average size when doped by Ag, it is seen from the morphology of Scanning Electron Microscope (SEM). EDX characterization using point analysis confirms that in samples with x = 0.05 (La0.8Ca0.15Ag0.05MnO3), the Ag ion have been successfully substituted. The result of the measurement of the composition of the two materials is not much different from the calculation, so it can be concluded that both materials have a good compositional purity.

Structural and morphological characterization of cuprate superconductor La2-xSrxCuO4 (x=0 and x=0.07) synthesized by sol-gel method

The La2-xSrxCuO4 materials with x=0 and x=0.07 were prepared by sol-gel method. These materials are the family of cuprate superconductor. These samples were heated three times by drying at 120°C for 2 hours, calcining at 500°C for 5 hours, and sintering at 700°C for 15 hours. The powder sample was pressed and compacted to be a bulk samples. These materials were characterized by X-Ray Diffraction (XRD) to study the structure of materials and Scanning Electron Microscopy – Electron Dispersive Spectroscopy (SEM-EDS) to study morphology and confirm the composition of materials. The results of XRD and High-Score application showed that the structure of both samples is orthorhombic (Cmca/64 space group). The substitution of Sr2+ ion with x = 0.07 to the La site did not change the crystal structure of material but it showed the variation of lattice parameter and unit cell volume. The variation indicated a decreasing of unit cell volume by substituting Sr2+ ion to La site. SEM-EDS characterization showed that both samples have homogeneity and confirmed that Sr2+ ion has successfully substituted to La site for La1.93Sr0.07CuO4 material. It also revealed that composition of both samples is similar to the stoichiometry calculation.

NiO/C3N4: hybrid photocatalyst for the enhanced photodegradation of organic pollutant under visible light

Photocatalysis utilizing semiconductor oxides is being researched widely for the degradation of dyes. This examination depicts the visible light actuated photocatalytic degradation of azo dye, methyl orange, utilizing NiO/C3N4 hybrid photocatalyst. The NiO/C3N4 hybrid photocatalyst with differing weight percentage were effectively synthesized by a simple calcinations method. The synthesized materials were described using x-ray diffraction, Fourier-transform infrared spectroscopy, Scanning electron microscopy-Electron dispersive spectroscopy, High resolution transmission spectroscopy, UV–vis diffuse reflectance spectroscopy, Atomic absorption spectroscopy and Photoluminescence. The photocatalytic action of NiO/C3N4 hybrid photocatalyst was assessed by the removal of methyl orange under visible light illumination (>400 nm). The loading of NiO on C3N4 was confirmed by AAS analysis. It is discovered that 4 wt% of NiO loaded C3N4 photocatalyst demonstrated maximum photocatalytic action and its comparing removal rate of methyl orange is accomplished 50% higher than that of bare g-C3N4 photocatalyst. Moreover, 78% of total organic carbon (TOC) removal was obtained with 4 wt% of NiO/C3N4 hybrid photocatalyst in 50 min.

Phase selection and mechanical properties of permanent-mold cast Mg-Al-Ca-Mn alloys and the role of Ca/Al ratio

In this work, phase selection, microstructure and mechanical properties of Mg-Al-Ca-Mn alloys with three different Ca/Al ratios (0.58, 0.79 and 0.91) were studied. The Mn content of the alloys was kept constant at ∼0.30 wt%. Thermodynamic non-equilibrium (Scheil) simulations, X-Ray Diffraction (XRD) analyses and Scanning Electron Microscopy/Electron Dispersive Spectroscopy (SEM/EDS) determined that all three alloys contain α-Mg solid solution phase, Al8Mn5 intermetallics and, depending on the Ca/Al ratio, combinations of C36-(Mg,Al)2Ca (hP24 a = 0.577–0.586 nm, c = 1.819–1.835 nm), binary C14-Mg2Ca (hP12, a = 0.620 nm c = 1.023 nm), ternary C14-Mg2Ca (hP12, a = 0.561–0.599 nm, c = 1.025–1.051 nm), and/or C15-Al2Ca (cF24, a = 0.793 nm) Laves phases. It is observed that Ca/Al ratio shows a direct relationship with the total amounts of Laves intermetallics and the amount of the C36 phase, and an indirect relationship with the amount of C14 phase. Microhardness measurements, room and elevated temperature (150 °C and 200 °C) tensile tests, as well as tensile creep tests (175 °C/50 MPa), were carried out to determine the mechanical properties of the alloys. Results show that the hardness and room temperature yield and ultimate tensile strengths (UTS) increase while the ductility at all temperatures decreases with increasing Ca/Al ratio. At elevated temperatures, in the range of Ca/Al ratios investigated, the UTS has a relationship with the dissolved amount of Ca and Mn in the α-Mg phase. Creep strain was found to decrease from 0.35% to 0.05% as Ca/Al increases from 0.6 to 0.9 and as the amount of the C36 phase which can strengthen grain boundaries increases. One order of magnitude improvement seen in creep resistance as the Ca/Al ratio increases from 0.6 to 0.8 is attributable to the presence of C36 and C14 phases rather than C36 and thermally unstable C15 phase in the alloys and to the increased amounts of dissolved Mn and Ca in the α-Mg matrix.

Ionic shot noise in an electrochemical capacitor system made of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) film and silver-coated polybenzoxazole-stainless steel electrodes on textile fabrics

Unusual noisy discharge profiles were observed from some of our textile-based energy storage devices having asymmetrical electrodes consisting of pure stainless steel and silver-coated polybenzoxazole yarns. Our hypothesis was that it was due to the ionic shot noise behavior that occurred in electrochemical devices and is a well-known phenomenon in electronic devices. The poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) polymer coverage on the cell surface, which functioned as a solid electrolyte in this system, was believed to play an important role. To confirm this assumption, devices made with different drop-coating strategies to obtain thin and thick layers of PEDOT:PSS polymer on the cell surface were prepared. The noisy discharge profiles were observed from devices with thin polymer layers, while those with thick layers exhibited normal discharge profiles. The morphology of cell surfaces was characterized by a stereo microscope. Cross-section analysis of a device with a thick layer was employed to further characterize its film formation and elemental properties using Scanning Electron Microscopy-Electron Dispersive Spectroscopy. Formation of multilayers of PEDOT:PSS polymer on the cell surface allowed a continuous interaction between electrode metals and PEDOT:PSS ions at the interface area. The noisy component was caused by the movement of silver ions hopping from one trap to the next. A qualitative model of the autocorrelation function executed to the data with noisy behavior further confirmed the ionic shot noise phenomenon.

Presence of skeletal banding in a reef-building tropical crustose coralline alga.

The presence of banding in the skeleton of coralline algae has been reported in many species, primarily from temperate and polar regions. Similar to tree rings, skeletal banding can provide information on growth rate, age, and longevity; as well as records of past environmental conditions and the coralline alga’s growth responses to such changes. The aim of this study was to explore the presence and characterise the nature of banding in the tropical coralline alga Porolithon onkodes, an abundant and key reef-building species on the Great Barrier Reef (GBR) Australia, and the Indo-Pacific in general. To achieve this we employed various methods including X-ray diffraction (XRD) to determine seasonal mol% magnesium (Mg), mineralogy mapping to investigate changes in dominant mineral phases, scanning electron microscopy–electron dispersive spectroscopy (SEM-EDS), and micro-computed tomography (micro-CT) scanning to examine changes in cell size and density banding, and UV light to examine reproductive (conceptacle) banding. Seasonal variation in the Mg content of the skeleton did occur and followed previously recorded variations with the highest mol% MgCO3 in summer and lowest in winter, confirming the positive relationship between seawater temperature and mol% MgCO3. Rows of conceptacles viewed under UV light provided easily distinguishable bands that could be used to measure vertical growth rate (1.4 mm year-1) and age of the organism. Micro-CT scanning showed obvious banding patterns in relation to skeletal density, and mineralogical mapping revealed patterns of banding created by changes in Mg content. Thus, we present new evidence for seasonal banding patterns in the tropical coralline alga P. onkodes. This banding in the P. onkodes skeleton can provide valuable information into the present and past life history of this important reef-building species, and is essential to assess and predict the response of these organisms to future climate and environmental changes.

Hybrid zero valent iron (ZVI)/H2O2 oxidation process for landfill leachate treatment with novel nanosize metallic calcium/iron composite

ABSTRACTA novel nanosize metallic calcium/iron dispersed reagent was synthesized and tested as coagulant/catalyst in a hybrid zero valent iron (ZVI)/H2O2 oxidation process to treat leachate. Two different types of leachates, one from municipal solid waste (MSW) tipping hall (MSWIL) and second from an MSW landfill site (MSWLL), were collected and characterized. The morphology, elemental composition, and mineral phases of the nano-Ca/CaO and nano-Fe/Ca/CaO were characterized by scanning electron microscopy–electron dispersive spectroscopy (SEM-EDS) and x-ray powder diffraction (XRD) analysis. The coagulation process with 2.5 g L−1 nano-Ca/CaO attained 64.0, 56.0, and 20.7% removal of color, chemical oxygen demand (COD), and total suspended solids (TSS) in MSWLL. With only 1.0 g L−1 of nano-Fe/Ca/CaO, relatively high color, COD and TSS removal was achieved in MSWLL at 67.5, 60.2, and 37.7%, respectively. The heavy metal removal efficiency reached 91–99% after treatment with nano-Fe/Ca/CaO in both leachate samples. The coupling process, using 1.0 g L−1 of nano-Fe/Ca/CaO and 20 mM H2O2 doses, achieved enhancement removal of color, COD, and TSS, up to 95%, 96%, and 66%, respectively, without initial pH control. After this treatment, the color, COD, TSS, and heavy metals were significantly decreased, fitting the Korean discharge regulation limit. A hybrid coupled zero valent iron (ZVI)/H2O2 oxidation process with novel nanosized metallic calcium/iron dispersed reagent proved to be a suitable treatment for dealing with leachate samples.Implications: Conventional treatments (biological or physicochemical) are not sufficient anymore to reach the level of purification needed to fully reduce the negative impact of landfill leachates on the environment. This implies that new treatment alternatives species must be proposed. A coupled zero valent iron (ZVI)/H2O2 oxidation process proved to be a suitable treatment for dealing with leachate samples. Coagulation with nFe/Ca/CaO allows 91–99% of heavy metals removal. The coupled coagulation–oxidation process by nFe/Ca/CaO reveals excellent ability to treat leachate. After coupled treatment the color, COD, and TSS were also much lower than the discharge regulation limit.

The archeology, sedimentology and paleontology of Gray's Reef National Marine Sanctuary and nearby hard bottom reefs along the mid continental shelf of the Georgia Bight

Geoarcheological surveys undertaken over the past two decades at Gray's Reef National Marine Sanctuary, 32km offshore Georgia, and nearby JY Reef have recovered archeological and paleontological materials dating from the Late Pleistocene, primarily Marine Isotope Stage (MIS) 3, 59–24KYBP as well as the early-to-mid Holocene, 6000 BP. The paleontological materials include both invertebrate and vertebrate taxa from both the Pleistocene and Holocene while the archeological materials are Holocene age. Sediment coring has developed a more comprehensive picture of the inner-to-mid continental shelf sediment prism of the Georgia Bight. Optical petrography, scanning electron microscopy, electron dispersive spectroscopy (SEM-EDS) and wavelength dispersive X-ray diffraction (XRD) have been used to characterize Gray's Reef lithic artifacts and nearby outcrops which are both primarily Pliocene age calcareous sandstones. JY Reef is, by contrast, a coquina rich in fossil and subfossil materials but depauperate in any archeologic finds. Petrologic and geochemical data have been developed for both the outcrops and artifacts that are in good agreement with previous studies using optical petrography.

&lt;i&gt;In Situ&lt;/i&gt; Characterization of Relevance of Surface Microstructure and Electrochemical Properties of&lt;i&gt; &lt;/i&gt;Chalcopyrite to Adsorption of &lt;i&gt;Acidianus manzaensis&lt;/i&gt;

The in situ relevance of micro- structure and electrochemical properties of chalcopyrite to adsorption of thermoacidophilic bioleaching Archaea Acidianus manzaensis was studied. In this study, the electrochemical behavior of chalcopyrite was first investigated by cyclic voltammetry (CV) to get suitable initial reduction and oxidation potentials, at which electrochemical corrosions of chalcopyrite for several time were performed, respectively, to get specific surface micro-structures. The specific adsorption of A. manzaensis on the electrochemically corroded chalcopyrite surface was then comparatively studied. The changes of microstructure and chemical composition/speciation on the surface of chalcopyrite before and after electrochemical treatment and bio-adsorption was characterized by scanning electron microscopy/electron dispersive spectroscopy (SEM/EDS), and synchrotron radiation-based X-ray diffraction (SR-XRD) and Fe, Cu K-edge X-ray absorption near edge structure (XANES) spectroscopy. The results showed that the suitable initial oxidation and reduction of chalcopyrite electrode were at 0.67 V for 1h and -0.54 V for 10 min, respectively. After treated at 0.67V the surface of chalcopyrite became Cu-deficient with a composition of CuFe1.02S2.15, and bornite (Cu5FeS4) was detected. While after treated at -0.54V, the surface became Fe/S-deficient, with a composition of CuFe0.33S0.81, and a mass of chalcocite and some covellite were detected. Comparing to the original chalcopyrite, the adsorption capacity of A. manzaensis was increased on the surface of oxidation-treatment at 0.67 V, and decreased on the surface of reduction-treatment at -0.54 V. It clearly demonstrates the bornite-containing copper deficient chalcopyrite surface was more preferably adsorbed, whereas the chalcocite-containing Fe/S deficient chalcopyrite surface was less adsorbed by A. manzaensis, indicating the dependence of the specific adsorption of A. manzaensis upon the secondary minerals as well as Fe/S availability in the microstructure of chalcopyrite.

Removal of Pb (II), Cd (II), Cu (II) and trichloroethylene from water by Nanofer ZVI

Zero-valent iron nanoparticle (Nanofer ZVI) is a new reagent due to its unique structure and properties. Images of scanning electron microscopy/electron dispersive spectroscopy (SEM/EDS), transmission electron microscopy and X-ray diffraction revealed that Nanofer ZVI is stable, reactive and has a unique structure. The particles exhibited a spherical shape, a chain-like structure with a particle size of 20 to 100 nm and a surface area between 25–30 m2g−1. The time interval for particles to agglomerate and settle was between 4–6 h. SEM/EDS Images showed that particle size increased to 2 µm due to agglomeration. Investigation of adsorption and oxidation behavior of Nanofer ZVI used for the removal of Cu(II), Pb(II), Cd(II) ions and trichloroethylene (TCE) from aqueous solutions showed that the optimal pH for Pb(II), Cu(II), Cd(II) and TCE removal were 4.5 and 4.8, 5.0 and 6.5, respectively. Test data were used to form Langmuir and Freundlich isotherms. The maximum contaminant loading was estimated as 270, 170, 110, 130 mg per gram of Nanofer ZVI for Cu(II), Pb(II), Cd(II) and TCE respectively. Removal of metal ions is interpreted in terms of their hydrated ionic radii and their electronegativity. TCE oxidation followed the dechlorination pathway resulting in nonhazardous by-products.

Synthesis of Electrolyte Polymer Based on Natural Polymer Chitosan by Ion Implantation Technique

This research is conducted to make solid-state electrolyte based on natural polymers, as an alternative material for energy storage such as battery. Natural polymers as materials of solid state batteries have various benefits, such as unlimited abundance, biodegradable, unleakage, stable form, excellent process, and electrochemical stability, compare to the liquid ones. In this study, a solid state polymer electrolyte based on natural polymer such as chitosan was synthesized by incorporating various ion salts (Li, Cu, Ag) in the polymer matrix. The synthesis of solid-state electrolyte polymer was carried out by casting method to make a thin polymer film. Then the ionic (Li, Cu, Ag) doping with various implant dose will be applied to the thin polymer film matrix by ionic implantation technique. The implanted polymer electrolytes are then characterized their conductivities, micro structures, and crystal structures by high precision LCR, scanning electron microscopy-electron dispersive spectroscopy (SEM-EDS), and X-ray diffraction (XRD), respectively. The measured of conductivities showed that thin film polymers after implanted with ionic Li, Cu or Ag were increased the conductivity, meanwhile elemental analisys by electron dispersive spectroscopy indicated that ionic implant to chitosan was success. The modification of chitosan polymer to become electrolyte polymer can be concluded.