scholarly journals Effect of Thiourea Containing Composite Additives on Nickel Electrodeposition in Ammoniacal Solution

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 43
Author(s):  
Liang Yuan ◽  
Jinhong Chen ◽  
Jingxiang Zhang ◽  
Lingna Sun
Keyword(s):  
Rational Design ◽  
Sodium Dodecyl ◽  
Nucleation Mechanism ◽  
Face Centered Cubic ◽  
Ammoniacal Solution ◽  
Sem Images ◽  
Step Potential ◽  
Nickel Electrodeposition ◽  
Nickel Deposits ◽  
Nucleation Overpotential

Composite additives have an important influence on the process of metal electrodeposition and the quality of a metal deposited layer. In this work, the additive thiourea (TU) was compounded with cetyltrimethyl ammonium chloride (CTAC), sodium dodecyl sulfate (SDS) and polyethylene glycol 20,000 (PEG20000), and their effect on the cyclic voltammetric behavior, electrochemical nucleation mechanism, crystallographic orientations and surface morphology of the nickel electrodeposition in ammoniacal solution were experimentally investigated. The results show that the introduction of composite additives resulted in a stronger cathodic polarization and increased the nucleation overpotential (NOP) values significantly, which had an important impact on forming compact and smooth nickel deposits. The chronoamperometry analysis indicated that the reduction in nickel followed the 3D progressive nucleation mechanism in the presence of composite additives at the step potential of −1.16 V and −1.18 V. Smoother and finer nickel films were found using scanning electron microscopy (SEM) images as the composite additives were used. X-ray diffraction revealed that all nickel deposit samples had the face-centered cubic structure, and five main crystal planes were displayed by the presence of composite additives in the electrolyte. Furthermore, the diffraction peaks of (111) and (200) crystal planes were slightly shifted toward lower 2θ values when thiourea was used in combination with additive CTAC or PEG20000. These results were beneficial for understanding the mechanisms and facilitating the rational design of additives for metal nickel electrodeposition.

scholarly journals Some aspects of nickel electrodeposition in the presence of a magnetic field

2005 ◽  
Vol 70 (10) ◽  
pp. 1213-1217 ◽  
Author(s):  
Nebojsa Nikolic
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Magnetic Properties ◽  
Dendritic Structure ◽  
Nickel Deposit ◽  
Nickel Electrodeposition ◽  
Nickel Deposits ◽  
Scanning Electron

Nickel deposits obtained from a Watt solution both without and with a perpendicularly oriented magnetic field were examined by scanning electron microscopy (SEM). The nickel deposit obtained without an imposed magnetic field was very rough, with a clearly visible clustered structure. The nickel deposit obtained under a perpendicularly oriented magnetic field has a very developed dendritic structure, which can be denoted as arboreous ? bead dendritic structure. The ob- served difference is essentially ascribed to the effect of a magnetic field on the magnetic properties of nickel.

scholarly journals Synthesis of Nano-sized Nickel Particles by a Bottom-up Approach in the Presence of an Anionic Surfactant and a Cationic Polymer

2010 ◽  
Vol 2 (2) ◽  
pp. 313-321 ◽  
Author(s):  
K. M. A. Haque ◽  
M. S. Hussain
Keyword(s):  
Anionic Surfactant ◽  
Sodium Dodecyl Sulphate ◽  
Sodium Dodecyl ◽  
Cationic Polymer ◽  
Sem Images ◽  
Bottom Up ◽  
Nonionic Polymer ◽  
Tem Characterization ◽  
Nickel Particles ◽  
Different Temperatures

Nano-sized nickel particles have been synthesized by a bottom-up approach, using hydrazine as the reducing agent in the presence of an anionic surfactant - sodium-dodecyl sulphate (SDS). The effect of adding a nonionic polymer -polyvinylpyrrolidone (PVP) with an anionic surfactant has been studied at two different temperatures; the rate of reduction increased as the reaction temperature was increased from 60 to 100°C. These nano-aggregated nickel particles were characterized by using SEM with EDX facilities and TEM. TEM characterization showed the presence of spherical Ni particles as fine as 10nm in diameter. However, the SEM images showed a very spiky morphology, very small spherical shaped objects were clearly observed within these spiky structures. The combination of SDS/PVP reaction produced nano-sized nickel particles which were much finer than the reactions where SDS was used on its own. PVP has shown some dispersion power, and was found to be capable of preventing nickel particles from gradual agglomeration.  Keywords: Bottom-up; SDS; PVP; 10 nm. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.       DOI:10.3329/jsr.v2i2.3261               J. Sci. Res. 2 (2), 313-321 (2010) 

Fabrication of Barium Titanate Inverse Opals by Sol-Gel Electrophoretic Deposition Process

2010 ◽  
Vol 434-435 ◽  
pp. 247-252 ◽  
Author(s):  
Bo Li ◽  
Jin Qing Wang ◽  
Rei Fujiwara ◽  
Makoto Kuwabara ◽  
Ming Fu ◽  
...  
Keyword(s):  
Barium Titanate ◽  
Photonic Crystals ◽  
Electrophoretic Deposition ◽  
Sol Gel ◽  
Deposition Process ◽  
Visible Range ◽  
Face Centered Cubic ◽  
Sem Images ◽  
Inverse Opals ◽  
Opal Template

Barium titanate (BTO) inverse opal photonic crystals were fabricated by a process of self-assembly of polystyrene opal template in combination with electrophoretic deposition (EPD) of nanoparticles from BTO suspension. In this process, stable monodispersed suspension of BTO nanoparticles was prepared by dispersing BTO gel into a mixed solvent of 2-methoxyethanol and acethylacetone. Then the BTO nanoparticles were infilled into the interstices of the opal template formed by monodisperse polystyrene microspheres by electrophoretic deposition, and then polystyrene template was removed by calcining the specimen at a final temperature of 500oC. SEM images show that the inverse opals possess face-centered cubic (fcc) structure with center to center distant of the air spheres 310 nm. A photonic bandgap in the visible range is observed from reflection spectra of the sample. Such BTO inverse opals as photonic crystals should be useful in device applications.

scholarly journals Green Synthesis of Silver Nanoparticles in the Presence of Polysaccharide: Optimization and Characterization

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Margarita I. Skiba ◽  
Victoria I. Vorobyova ◽  
Alexander Pivovarov ◽  
Natalya P. Makarshenko
Keyword(s):  
Silver Nanoparticles ◽  
Sodium Alginate ◽  
Xrd Analysis ◽  
Face Centered Cubic ◽  
Colloidal Solutions ◽  
Ag Nps ◽  
Sem Images ◽  
Spherical Powder ◽  
Stabilizing Agent ◽  
Vis Spectroscopy

The process of obtaining aqueous solutions of silver nanoparticles with the use of a low-temperature nonequilibrium contact plasma and stabilizing agent—polysaccharide (sodium alginate)—has been examined. The synthesized Ag NPs were characterized by using UV-Vis spectroscopy, dynamic light scattering (DLS), scanning electron microscope (SEM), and XRD analysis. The effect of concentration of Ag+, sodium alginate, duration of processing by plasma discharge, and pH of liquid on the production of silver nanoparticles has been studied. The results demonstrated that synthesis provides the formation of silver nanoparticles for investigated concentrations of Ag+ (0.3-3.0 mmol/l) and 5.0 g/l Na-Alg (pH=7–10) within 1–5 minutes. From the SEM images, the silver nanoparticles are found to be almost spherical. Powder XRD results reveal that Ag nanoparticles have a face-centered cubic crystal structure. Zeta potential of plasma-chemically obtained colloidal solutions at various concentrations of Ag+ ions and stabilizing agent varies from −32.8 to −39.3 mV, indicating the moderate stability of synthesized nanoparticles.

scholarly journals Mechanical Properties Enhancement of the Au-Cu-Al Alloys via Phase Constitution Manipulation

2021 ◽  
Author(s):  
Kang Wei Goo ◽  
Wan–Ting Chiu ◽  
Ayano Toriyabe ◽  
Masahiro Homma ◽  
Akira Umise ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Deformation ◽  
Optical Microscope ◽  
Alpha Phase ◽  
Martensite Phase ◽  
Face Centered Cubic ◽  
Sem Images ◽  
Stress Plateau ◽  
The Face ◽  
Reflectance Analysis

To enhance the mechanical properties (i.e. strength and elongation) of the face-centered cubic (fcc) α-phase in the Au-Cu-Al system, this study focused on the introduction of the martensite phase (doubled B19 (DB19) crystal structure of Au2CuAl) via the manipulation of alloy compositions. Fundamental evaluations, such as microstructure observations, phase identifications, thermal analysis, tensile behavior examinations, and reflectance analysis have been conducted. The presence of fcc annealing twins was both observed in the optical microscope (OM) and the scanning electron microscope (SEM) images. Both the strength and elongation of the alloys were greatly promoted while the DB19 martensite phase was introduced into the alloys. Amongst all the prepared specimens, the 47Au41Cu12Al and the 44Au44Cu12Al alloys performed the optimized mechanical properties. The enhancement of strength and ductility in these 2 alloys was achieved while the stress plateau was observed during the tensile deformation. A plot of the ultimate tensile strength (UTS) against fracture strain was constructed to illustrate the effects of the introduction of the DB19 martensite phase on the mechanical properties of the alloys. Regardless of the manipulation of the alloy compositions and the introduction of the DB19 martensite phase, the reflectance stayed almost identical to pure Au.

scholarly journals Electrochromic Self-Electrostabilized Polypyrrole Films Doped with Surfactant and Azo Dye

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1757 ◽  
Author(s):  
Bayat ◽  
Izadan ◽  
Molina ◽  
Sánchez ◽  
Santiago ◽  
...  
Keyword(s):  
Sodium Dodecyl ◽  
Polymerization Reaction ◽  
X Ray Diffraction ◽  
Step Potential ◽  
Polypyrrole Films ◽  
Oxidation Reduction ◽  
Redox Capacity ◽  
Pyrrole Monomer ◽  
Red Color ◽  
Sds Surfactant

Two azo dyes, acid red 1 (AR1) and acid red 18 (AR18), were used alone or in combination with sodium dodecyl sulfate (SDS) for the electropolymerization of a pyrrole monomer. Polypyrrole (PPy) showed higher redox capacity when SDS and AR18 were used simultaneously as dopant agents (PPy/AR18-SDS) than when the conducting polymer was produced in the presence of SDS, AR18, AR1, or an AR1/SDS mixture. Moreover, PPy/AR18-SDS is a self-stabilizing material that exhibits increasing electrochemical activity with the number of oxidation–reduction cycles. A mechanism supported by scanning electron microscopy and X-ray diffraction structural observations was proposed to explain the synergy between the SDS surfactant and the AR18 dye. On the other hand, the Bordeaux red color of PPy/AR18-SDS, which exhibits an optical band gap of 1.9 eV, rapidly changed to orange-yellow and blue colors when films were reduced and oxidized, respectively, by applying linear or step potential ramps. Overall, the results indicate that the synergistic utilization of AR18 and SDS as dopant agents in the same polymerization reaction is a very successful and advantageous strategy for the preparation of PPy films with cutting-edge electrochemical and electrochromic properties.

scholarly journals Microemulsions as Nanoreactors for Preparation of Nanoparticles with Antibacterial Activity

2012 ◽  
Vol 25 (1) ◽  
pp. 71-79 ◽  
Author(s):  
Sakhawat Hossain ◽  
Ummul K Fatema ◽  
Md Yousuf A Mollah ◽  
M Muhibur Rahman ◽  
Md Abu Bin Hasan susan
Keyword(s):  
Antibacterial Activity ◽  
Copper Nanoparticles ◽  
Copper Chloride ◽  
Sodium Dodecyl ◽  
Antibiotic Sensitivity ◽  
Chemical Society ◽  
Molar Ratio ◽  
Electron Microscopic ◽  
Sem Images ◽  
E Coli

Nanoparticles of silver and copper have been synthesized by reduction of aqueous silver  nitrate and copper chloride solutions with sodium borohydride in anionic water-in-oil  (w/o) microemulsions, sodium dodecyl sulphate (SDS)/1-pentanol/cyclohexane/water.  Scanning electron microscopic (SEM) images, energy dispersive spectra (EDX) and UVspectra  have been used to characterize the resultant nanoparticles. The average size of the  nanoparticles has been found to be influenced by the water to surfactant molar ratio (Wo)  in the microemulsions. Smaller particles are obtained at low Wo, while higher Wo yields  larger particles. The antibiotic sensitivity of silver and copper nanoparticles against  Escherichia coli (E. coli) was tested by zone inhibition method using nanoparticles in  ethanol suspension. Both silver and copper nanoparticles showed the potential for use as  antibacterial agents against E. coli with sensitivity as good as conventional antibiotics.  Silver nanoparticles show higher antibacterial activity against E. coli, compared to copper nanoparticles. As the amount of the nanoparticles in the suspension decreases, antibacterial activity decreases; however the concentration dependence on antibacterial  activity has been less pronounced. DOI: http://dx.doi.org/10.3329/jbcs.v25i1.11777 Journal of Bangladesh Chemical Society, Vol. 25(1), 71-79, 2012

scholarly journals In Vitro Mechanism Assessment of Zearalenone Removal by Plant-Derived Lactobacillus plantarum BCC 47723

Toxins ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 286
Author(s):  
Saowalak Adunphatcharaphon ◽  
Awanwee Petchkongkaew ◽  
Wonnop Visessanguan
Keyword(s):  
Heat Treatment ◽  
Zeta Potential ◽  
Lactobacillus Plantarum ◽  
Cell Structure ◽  
Sodium Dodecyl ◽  
Pathogenic Fungi ◽  
Bacterial Cells ◽  
Sem Images ◽  
Removal Capacity

Zearalenone (ZEA) is a harmful secondary fungal metabolite, produced primarily by plant pathogenic fungi mostly belonging to the genus Fusarium. It is involved in reproductive disorders in animals since its structure is similar to the estrogen hormone. This induces precocious pubertal changes, fertility problems, and hyper estrogenic disorders. The main objectives of this study were to evaluate the ZEA removal capacity of plant-derived lactic acid bacteria (LAB) and to investigate the possible components and mechanisms involved in the removal of ZEA by physically and chemically treated plant-derived LAB. The bacterial cells were characterized using scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), and the analysis of zeta potential, and hydrophobic index. Results revealed that 17 out of 33 plant-derived LAB exhibited ZEA removal from liquid medium. The percentage of removal ranged from 0.5–23% and Lactobacillus plantarum BCC 47723, isolated from wild spider flower pickle (Pag-sian-dorng), exhibited the highest removal. The alteration of proteins on L. plantarum BCC 47723 structure by Sodium dodecyl sulphate (SDS) treatment was positively affected on ZEA removal, whereas that of lipids on ZEA removal was negatively observed. Heat treatment influenced the higher ZEA adsorption. SEM images showed that the morphologies of modified bacterial cells were distinctly deformed and damaged when compared with untreated control. FTIR analysis indicated that the original functional groups, which included amide (C=O, C-N), carboxyl (C=O, C-O, O-H), methylene (C=C), and alcohol (O-H) groups, were not changed after ZEA adsorption. The zeta potential indicated that electrostatic interaction was not involved in the ZEA removal, while hydrophobicity was the main force to interact with ZEA. These findings can conclude that adsorption by hydrophobicity is the main mechanism for ZEA removal of plant-derived L. plantarum BCC 47723. The alteration of bacterial cell structure by heat treatment enhanced the efficiency of L. plantarum BCC 47723 for ZEA reduction. Its activity can be protected by the freeze-drying technique. Hence, plant-derived L. plantarum BCC 47723 can be considered as an organic adsorbent for ZEA reduction in food and feedstuff.

Influences of Various Peptide Linkers on the Thermotoga maritima MSB8 Nitrilase Displayed on the Spore Surface of Bacillus subtilis

2017 ◽  
Vol 27 (1) ◽  
pp. 64-71 ◽  
Author(s):  
Huayou Chen ◽  
Zhi Chen ◽  
Bangguo Wu ◽  
Jawad Ullah ◽  
Tianxi Zhang ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Fusion Proteins ◽  
Rational Design ◽  
Thermotoga Maritima ◽  
Sodium Dodecyl ◽  
Ph Stability ◽  
Activity Measurement ◽  
Spore Surface ◽  
Outer Coat ◽  
The Stability

In the present study, fusion genes composed of <i>Thermotoga maritima</i> MSB8 nitrilase and <i>Bacillus subtilis</i> 168 outer coat protein CotG were constructed with various peptide linkers and displayed on <i>B. subtilis</i> DB 403 spores. The successful display of CotG-nit fusion proteins on the spore surface of <i>B. subtilis</i> was verified by Western blot analysis and activity measurement. It was demonstrated that the fusion with linker GGGGSEAAAKGGGGS presented the highest thermal and pH stability, which is 2.67- and 1.9-fold of the fusion without linker. In addition, fusion with flexible linker (GGGGS)<sub>3</sub> demonstrated better thermal and pH stability than fusions with linkers GGGGS and (GGGGS)<sub>2</sub>. Fusion with rigid linker (EAAAK) demonstrated better thermal stability than fusions with linkers (EAAAK)<sub>2</sub> and (EAAAK)<sub>3</sub>. Fusions with linker (EAAAK)<sub>2</sub> demonstrated better pH stability than fusions with linkers (EAAAK) and (EAAAK)<sub>3</sub>. In the presence of 1 m<smlcap>M</smlcap> dithiothreitol, 1% (v/v) sodium dodecyl sulfate, and 20% (v/v) ethanol, the optimal linkers of the fusions were MGSSSN, GGGGSEAAAKGGGGS, and (GGGGS)<sub>3</sub>, respectively. In summary, our results showed that optimizing the peptide linkers with different type, length, and amino acid composition of the fusion proteins would be an efficient way to maintain the stability of fusion proteins and thus improve the nitrilase display efficiency, which could provide an effective method for rational design peptide linkers of displayed nitrilase on <i>B. subtilis</i>.

scholarly journals Hypericum perforatum L.-Mediated Green Synthesis of Silver Nanoparticles Exhibiting Antioxidant and Anticancer Activities

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 487 ◽  
Author(s):  
Abdalrahim Alahmad ◽  
Armin Feldhoff ◽  
Nadja C. Bigall ◽  
Pascal Rusch ◽  
Thomas Scheper ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Hypericum Perforatum ◽  
Nitrate Solution ◽  
A549 Cells ◽  
Metallic Silver ◽  
Synthesis Methods ◽  
Face Centered Cubic ◽  
Sem Images ◽  
Hypericum Perforatum L

This contribution focuses on the green synthesis of silver nanoparticles (AgNPs) with a size < 100 nm for potential medical applications by using silver nitrate solution and Hypericum Perforatum L. (St John’s wort) aqueous extracts. Various synthesis methods were used and compared with regard to their yield and quality of obtained AgNPs. Monodisperse spherical nanoparticles were generated with a size of approximately 20 to 50 nm as elucidated by different techniques (SEM, TEM). XRD measurements showed that metallic silver was formed and the particles possess a face-centered cubic structure (fcc). SEM images and FTIR spectra revealed that the AgNPs are covered by a protective surface layer composed of organic components originating from the plant extract. Ultraviolet-visible spectroscopy, dynamic light scattering, and zeta potential were also measured for biologically synthesized AgNPs. A potential mechanism of reducing silver ions to silver metal and protecting it in the nanoscale form has been proposed based on the obtained results. Moreover, the AgNPs prepared in the present study have been shown to exhibit a high antioxidant activity for 2, 2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cation, and super oxide anion radical and 2,2-diphenyl-1-picrylhydrazyl. Synthesized AgNPs showed high cytotoxicity by inhibiting cell viability for Hela, Hep G2, and A549 cells.

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