scholarly journals Effect of High Temperature Sodium Hydroxide Immersion on Fusion Bond Epoxy Coating

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Amal Al-Borno ◽  
Xianyi Chen ◽  
Shailesh Kewaldas Dhoke
Keyword(s):  
Sodium Hydroxide ◽  
Electrochemical Impedance ◽  
Analytical Techniques ◽  
Attenuated Total Reflection ◽  
Low Molecular Weight ◽  
Scanning Calorimetry ◽  
Premature Failure ◽  
X Ray ◽  
Deposit Layer

Fusion Bond Epoxy (FBE) coating system was exposed to 5% sodium hydroxide at elevated temperature for 30 days. The result of exposure showed formation of adhere deposit layer, a discolored zone underneath and remaining un-affected bulk of the coating. The deterioration of the coating was characterized using analytical techniques like scanning electron microscopy (SEM), energy-dispersive X-ray (EDAX) spectroscopy, attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), pull-off adhesion, and electrochemical impedance spectroscopy (EIS). Results obtained indicated chemical deterioration of the coating in the discolored zone and leaching of low molecular weight coating component forming deposit layer. Although the adhesion strength and barrier property were not affected, the polymer matrix in the affected zone undergoes severe changes in its surface microstructure, primary chemical structure, and glass transition temperature. This may inflict serious impairment of the coating functional properties and premature failure of the coating in long term exposure.

scholarly journals Instrumental Techniques for Characterization of Molybdenum Disulphide Nanostructures

2020 ◽  
Vol 2020 ◽  
pp. 1-29
Author(s):  
Kabelo E. Ramohlola ◽  
Emmanuel I. Iwuoha ◽  
Mpitloane J. Hato ◽  
Kwena D. Modibane
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Analytical Techniques ◽  
Great Accuracy ◽  
Molybdenum Disulphide ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Electron Microscopies ◽  
Energy Applications ◽  
Transmission Electron

The excellent chemical and physical properties of materials (nanomaterials) with dimensions of less than 100 nm (nanometers) resulted in researchers and industrialists to have great interest in their discovery and applications in various systems/applications. As their sizes are reduced to nanoscale, these nanomaterials tend to possess exceptional properties differing from those of their bulk counterparts; hence, they have found applications in electronics and medicines. In order to apply them in those applications, there is a need to synthesise these nanomaterials and study their structural, optical, and electrochemical properties. Among several nanomaterials, molybdenum disulphide (MoS2) has received a great interest in energy applications due to its exceptional properties such as stability, conductivity, and catalytic activities. Hence, the great challenge lies in finding the state-of-the-art characterization techniques to reveal the different properties of MoS2 nanostructures with great accuracy. In this regard, there is a need to study and employ several techniques to accurately study the surface chemistry and physics of the MoS2 nanostructures. Hence, this review will comprehensively discuss a detailed literature survey on analytical techniques that can be used to study the chemical, physical, and surface properties of MoS2 nanostructures, namely, ultraviolet-visible spectroscopy (UV-vis), photoluminescence spectroscopy (PL), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, time-of-flight secondary ion mass spectroscopy (TOF-SIMS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning and transmission electron microscopies (SEM and TEM), atomic force microscopy (AFM), energy dispersive X-ray spectroscopy (EDS/X), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and electroanalytical methods which include linear sweep (LSV) and cyclic (CV) voltammetry and electrochemical impedance spectroscopy (EIS).

scholarly journals Silver Nanoparticles from Oregano Leaves’ Extracts as Antimicrobial Components for Non-Infected Hydrogel Contact Lenses

2021 ◽  
Vol 22 (7) ◽  
pp. 3539
Author(s):  
Anastasia Meretoudi ◽  
Christina N. Banti ◽  
Panagiotis K. Raptis ◽  
Christina Papachristodoulou ◽  
Nikolaos Kourkoumelis ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Contact Lenses ◽  
Attenuated Total Reflection ◽  
Bacterial Strains ◽  
Scanning Calorimetry ◽  
X Ray ◽  
E Coli ◽  
Polymer Hydrogels ◽  
20 Nm ◽  
And Staphylococcus Aureus

The oregano leaves’ extract (ORLE) was used for the formation of silver nanoparticles (AgNPs(ORLE)). ORLE and AgNPs(ORLE) (2 mg/mL) were dispersed in polymer hydrogels to give the pHEMA@ORLE_2 and pHEMA@AgNPs(ORLE)_2 using hydroxyethyl–methacrylate (HEMA). The materials were characterized by X-ray fluorescence (XRF) spectroscopy, X-ray powder diffraction analysis (XRPD), thermogravimetric differential thermal analysis (TG-DTA), derivative thermogravimetry/differential scanning calorimetry (DTG/DSC), ultraviolet (UV-Vis), and attenuated total reflection mode (ATR-FTIR) spectroscopies in solid state and UV–Vis in solution. The crystallite size value, analyzed with XRPD, was determined at 20 nm. The antimicrobial activity of the materials was investigated against Gram-negative bacterial strains Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli). The Gram-positive ones of the genus of Staphylococcus epidermidis (S. epidermidis) and Staphylococcus aureus (S. aureus) are known to be involved in microbial keratitis by the means of inhibitory zone (IZ), minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The IZs, which developed upon incubation of P. aeruginosa, E. coli, S. epidermidis, and S. aureus with paper discs soaked in 2 mg/mL of AgNPs(ORLE), were 11.7 ± 0.7, 13.5 ± 1.9, 12.7 ± 1.7, and 14.3 ± 1.7 mm. When the same dose of ORLE was administrated, the IZs were 10.2 ± 0.7, 9.2 ± 0.5, 9.0 ± 0.0, and 9.0 ± 0.0 mm. The percent of bacterial viability when they were incubated over the polymeric hydrogel discs of pHEMA@AgNPs(ORLE)_2 was interestingly low (66.5, 88.3, 77.7, and 59.6%, respectively, against of P. aeruginosa, E. coli, S. epidermidis, and S. aureus) and those of pHEMA@ORLE_2 were 89.3, 88.1, 92.8, and 84.6%, respectively. Consequently, pHEMA@AgNPs(ORLE)_2 could be an efficient candidate toward the development of non-infectious contact lenses.

scholarly journals High Throughput Screening and Characterization Methods of Jordanian Oil Shale as a Case Study

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3148 ◽  
Author(s):  
Ziad Abu El-Rub ◽  
Joanna Kujawa ◽  
Esra’a Albarahmieh ◽  
Nafisah Al-Rifai ◽  
Fathieh Qaimari ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Oil Shale ◽  
Analytical Techniques ◽  
Economic Feasibility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Characterization Methods ◽  
X Ray ◽  
Hydrogen Mass

Oil shale is an important possible solution to the problem of energy in Jordan. To explore the technical and the economic feasibility of oil shale deposits, numerous samples are analyzed using the standard Fischer Assay (FA) method. However, it would be useful to develop faster, cheaper, and reliable methods for determining the oil content of oil shale. Therefore, the aim of this work was to propose and investigate rapid analytical techniques for the screening of oil shale deposits and to correlate them with the FA method. The Omari deposit located east of Jordan was selected as a case study for analysis using thermogravimetric analysis (TGA) coupled with Fourier-transform infrared (FTIR), differential scanning calorimetry (DSC), elemental analysis, X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) analysis. Results obtained from the TGA method were linearly correlated with FA with high regression factor (R2 = 0.99); a quadratic correlation (R2 = 0.98) was maintained between the FA and the elemental hydrogen mass content, and a quadratic correlation (R2 = 0.97) was found between the FA and the aliphatic hydrocarbons (FTIR peak at 2927 cm−1) produced in the pyrolysis zone. Although other techniques were less correlated, further investigation might lead to better results. Subsequently, these correlated techniques can be a practical alternative to the conventional FA method when, in particular, specific correlation is made for each deposit.

Physicochemical Characteristics of an Ultra-Thin Hydrophobic Trichlorosilanes Using SiO2 as Adhesion

2019 ◽  
Vol 796 ◽  
pp. 80-87
Author(s):  
Akinsanya Damilare Baruwa ◽  
Esther Titilayo Akinlabi ◽  
Oluseyi Philip Oladijo ◽  
Stephen Akinwale Akinlabi ◽  
Jeff Chinn
Keyword(s):  
Room Temperature ◽  
Electrochemical Impedance ◽  
Physicochemical Characteristics ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Natural Seawater ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrophobic Silane ◽  
Better Than

The aim of the research is to subject the three different silanes to chemical and electrochemical investigations in other to determine the most efficient organic compound. Three types of hydrophobic silanes [Tris (Trimethylsiloxy) silyethyl] dimethylchlorosilane (Alkyl); Tridecafloro-1,1,2,2-tetrahydrooctyltrichlorosilane (FOTS) and Henicosyl-1,1,2,2-tetrahydrododecyltricholrosilane (FDDTS) are presented and investigated. The three silanes are of different composition but are deposited at the same parameters and conditions. The chemical investigation was studied through (attenuated total reflection Fourier-transform infrared (ATR-FTIR) and x-ray diffraction (XRD), while the electrochemical study was conducted through EIS using natural seawater electrolyte at room temperature. From the investigation techniques, only electrochemical impedance results show that FDDTS performed better than both Alkyl and FOTS. The chemical analysis showed the presence of hydrophobic silane on all the coated samples, and no distinction can be drawn from associated peaks.

scholarly journals Organogels for the cleaning of artifacts

2017 ◽  
Vol 89 (1) ◽  
pp. 3-17 ◽  
Author(s):  
Maria Diletta Pianorsi ◽  
Martina Raudino ◽  
Nicole Bonelli ◽  
David Chelazzi ◽  
Rodorico Giorgi ◽  
...  
Keyword(s):  
Release Rate ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Polymeric Networks ◽  
X Ray Scattering ◽  
Paper Document ◽  
New Formulation ◽  
Differential Thermogravimetry

AbstractThe cleaning of artifacts must not alter the original properties of the objects. While the use of free solvents is risky, their confinement into polymeric networks can allow the safe removal of unwanted layers from artifacts. Recently, a methyl 2-methylprop-2-enoate (MMA)-based organogel was formulated as loaded with butan-2-one (MEK), and used to remove aged varnishes from canvas paintings. However, this formulation is not enough retentive to allow its use on paper, where higher retentiveness is needed to avoid the uncontrolled spreading of MEK and dissolved materials. Here, a new PMMA-MEK gel was designed to overcome this limitation. The amount of cross-linker and monomer used in the synthesis of the gel were tuned to achieve optimal retentiveness. Differential scanning calorimetry (DSC), differential thermogravimetry (DTG), small-angle X-ray scattering (SAXS) and attenuated total reflection fourier transform infrared spectroscopy (ATR-FTIR) provided information on the solvent content, release rate, and mesoporosity of the gel as compared to the previous system. The lower solvent release rate of the new formulation allowed the safe removal of wax that jeopardized a 19th century paper document. The removal was confirmed through optical microscopy and ATR-FTIR, which also highlighted the absence of gel residues on the treated surface.

Characterization of groundnut shell powder as a potential reinforcement for biocomposites

2021 ◽  
pp. 204124792110087
Author(s):  
Mohammed Awwalu Usman ◽  
Ibrahim Momohjimoh ◽  
Abdulhafiz Onimisi Usman
Keyword(s):  
Sodium Hydroxide ◽  
Natural Fiber ◽  
Glass Fibers ◽  
Natural Fibers ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Consequent Reduction ◽  
Groundnut Shell ◽  
The Right ◽  
Shell Powder

Natural fibers are becoming the right candidate material as a substitute for glass fibers in the reinforcement of plastic polymers for various applications. The ease of their processing with minimal energy consumption and the quest to produce biodegradable plastics with lightweight has given natural fibers comparative advantages over synthetic fibers. In this study, groundnut shell powder (GSP) in different forms (untreated, sodium hydroxide treated and ash) were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR), X-ray fluorescence (XRF), Nuclear magnetic resonance (NMR), Differential scanning calorimetry (DSC) and Scanning electron microscopy (SEM) to evaluate their possible utilization as reinforcement in polymers. GSP was treated with sodium hydroxide for 5 hrs and dried in vacuum for 24 hrs to obtain treated GSP while ash GSP was formed by heating GSP in the furnace at 600 °C for about 3 hrs. The results reveal that sodium hydroxide treatment was very effective in the breaking down of the hydrogen bond with a consequent reduction in the hydrophilicity of the GSP. This would promote GSP bonding with the hydrophobic polymer matrix in the development of natural fiber reinforced plastic polymer composite materials. Ash GSP was found to have the highest crystallinity among the three forms of GSP based on XRD results. Therefore, the result achieved in this work confirmed that treated and ash GSP fibers are good reinforcement material in the production of polymer composites, with the actual choice depending on end-use property requirements of the composite.

Nanostructured manganese oxides and their composites with carbon nanotubes as electrode materials for energy storage devices

2008 ◽  
Vol 80 (11) ◽  
pp. 2327-2343 ◽  
Author(s):  
V. Subramanian ◽  
Hongwei Zhu ◽  
Bingqing Wei
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Manganese Oxides ◽  
Electrode Materials ◽  
Electrochemical Impedance ◽  
Analytical Techniques ◽  
Energy Storage Devices ◽  
X Ray ◽  
Storage Devices

Manganese oxides have been synthesized by a variety of techniques in different nanostructures and studied for their properties as electrode materials in two different storage applications, supercapacitors (SCs) and Li-ion batteries. The composites involving carbon nanotubes (CNTs) and manganese oxides were also prepared by a simple room-temperature method and evaluated as electrode materials in the above applications. The synthesis of nanostructured manganese oxides was carried out by simple soft chemical methods without any structure directing agents or surfactants. The prepared materials were well characterized using different analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), surface area studies, etc. The electrochemical properties of the nanostructured manganese oxides and their composites were studied using cyclic voltammetry (CV), galvanostatic charge-discharge, and electrochemical impedance spectroscopic (EIS) studies. The influence of structural/surface properties on the electrochemical performance of the synthesized manganese oxides is reviewed.

Long-Term SOFCs Button Cell Testing

2013 ◽  
Vol 11 (2) ◽  
Author(s):  
Gianfranco DiGiuseppe ◽  
Li Sun
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Current Density ◽  
Electrochemical Impedance ◽  
X Ray ◽  
Total Polarization ◽  
Scanning Electron

This paper reports a new study where relatively long-term tests of about a 1000 h are performed on several planar anode-supported solid oxide fuel cells. The cell electrochemical behaviors are studied by using voltage-current density measurement, electrochemical impedance spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The cell total polarization obtained from electrochemical impedance spectroscopy results is shown to be consistent with the area-specific resistance calculated from the voltage-current density curve over the course of the test. In addition, a four-constant phase element model is used to analyze the cell components resistances at different intervals over the lifetime of the test. Scanning electron microscopy and energy-dispersive X-ray spectroscopy are used postmortem to determine if any damages occurred to the cells and to determine if any change in composition occurred to the lanthanum strontium cobalt ferrite cathode. This study shows that the tested cells remain stable with a relatively small increase in the cell total polarization but with no increase in ohmic resistance.

scholarly journals Toward an Understanding of the Formation and Desolvation of Methanol Solvate, and Structure of Methanolysis Product: A Case Study of Nicosulfuron

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 157
Author(s):  
Huaxiang Zhu ◽  
Bei Zhang ◽  
Di Wu ◽  
Xiaowei Cheng ◽  
Guiping Li ◽  
...  
Keyword(s):  
Solid Phase ◽  
Great Influence ◽  
Acid Methyl Ester ◽  
Analytical Techniques ◽  
Systematic Investigation ◽  
Herbicidal Activity ◽  
Carbamic Acid ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

Nicosulfuron (NS) is a widely used sulfonylurea herbicide because of its high selectivity, broad spectrum of herbicide activity, and excellent performance. In this work, nicosulfuron methanol solvate (NS-MeOH) and [[3-[(Dimethylamino)carbonyl]-2-pyridinyl]sulfonyl]carbamic acid methyl ester (PCM) as a product of methanolysis of NS were obtained. Both of their structures were determined by a single crystal X-ray diffraction. A broad range of analytical techniques was applied to characterize the NS-MeOH, such as Powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and hot stage microscopy (HSM). Combined with the analysis of the Independent gradient model (IGM), Atom-in-molecules (AIM), and Hirshfeld surface (HS), direct insights into the role of solvent played in the formation of NS-MeOH and the mechanism of solid-to-solid phase transformation of NS-MeOH could be obtained. In addition, the aqueous solubility of NS was improved through the formation of NS-MeOH. A systematic investigation of herbicidal activity of NS and PCM was carried out. It was found that NS and NS-MeOH had similar herbicidal activities at the experimental concentrations while PCM exhibited significantly lower activity. It was suggested that methanolysis of the sulfonylurea bridge in the NS molecule exerted a great influence on the herbicidal activity.

Influence of Plasticizers on the Electrical Conductivity of Polyacrylonitrile (PAN)/Lithium-Montmorillonite (Li-MMT) Polymer Composite Electrolyte

2017 ◽  
Vol 894 ◽  
pp. 89-93
Author(s):  
Mitch Irene Kate N. Galvan ◽  
Leslie Joy L. Diaz
Keyword(s):  
Electrical Conductivity ◽  
Polymer Composite ◽  
Electrochemical Impedance ◽  
Current Trend ◽  
Xrd Analysis ◽  
Dimethyl Formamide ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Composite Electrolyte ◽  
X Ray

With the current trend of miniaturization and portability of electronic gadgets, the development of polymer composite electrolyte (PCE) gained much research interest. In this study PAN matrix was plasticized with various dimethyl formamide (DMF)/ propylene carbonate (PC) ratios. X-ray diffraction (XRD) analysis revealed that both DMF and PC reduce the crystallinity of PAN. Yet, films with higher amount of PC caused much decrease in crystallinity, which is indicated by lowering of full with at half maximum (FWHM) at the utmost 57% when the DMF/PC ratio is 1:2. Differential scanning calorimetry (DSC) analysis also revealed that glass transition temperature (Tg) of PAN decreased from 83.34°C to 50.27°C when plasticized with pure DMF and to temperature lower than ambient condition when PC alone was used. Upon incorporation of 15 wt% Li-MMT, PCEs with pure DMF exhibited the highest electrical conductivity, which is 3.6x10-8 S/cm based on electrochemical impedance spectroscopy (EIS). This suggests that the electrical conductivity is not dictated by the decrease on polymer host crystallinity alone. The type of plasticizer and appropriate combination was shown to have an effect wherein the plasticizer that causes higher degree of solvation and has lower boiling point is thought to provide more hopping sites for electrons due to higher amount of broken bonds in the nitrile group of PAN.

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