Displaying publications 21 - 40 of 102 in total

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  1. Fulltext Microstructural, Tribology and Corrosion Properties of Optimized Fe3O4-SiC Reinforced Aluminum Matrix Hybrid Nano Filler Composite Fabricated through Powder Metallurgy Method
    Ashrafi N, Azmah Hanim MA, Sarraf M, Sulaiman S, Hong TS
    Materials (Basel), 2020 Sep 15;13(18).
    PMID: 32942621 DOI: 10.3390/ma13184090
    Hybrid reinforcement's novel composite (Al-Fe3O4-SiC) via powder metallurgy method was successfully fabricated. In this study, the aim was to define the influence of SiC-Fe3O4 nanoparticles on microstructure, mechanical, tribology, and corrosion properties of the composite. Various researchers confirmed that aluminum matrix composite (AMC) is an excellent multifunctional lightweight material with remarkable properties. However, to improve the wear resistance in high-performance tribological application, hardening and developing corrosion resistance was needed; thus, an optimized hybrid reinforcement of particulates (SiC-Fe3O4) into an aluminum matrix was explored. Based on obtained results, the density and hardness were 2.69 g/cm3, 91 HV for Al-30Fe3O4-20SiC, after the sintering process. Coefficient of friction (COF) was decreased after adding Fe3O4 and SiC hybrid composite in tribology behaviors, and the lowest COF was 0.412 for Al-30Fe3O4-20SiC. The corrosion protection efficiency increased from 88.07%, 90.91%, and 99.83% for Al-30Fe3O4, Al-15Fe3O4-30SiC, and Al-30Fe3O4-20SiC samples, respectively. Hence, the addition of this reinforcement (Al-Fe3O4-SiC) to the composite shows a positive outcome toward corrosion resistance (lower corrosion rate), in order to increase the durability and life span of material during operation. The accomplished results indicated that, by increasing the weight percentage of SiC-Fe3O4, it had improved the mechanical properties, tribology, and corrosion resistance in aluminum matrix. After comparing all samples, we then selected Al-30Fe3O4-20SiC as an optimized composite.
    Matched MeSH terms: Corrosion
  2. Fulltext Synergetic Effects of Hybrid Carbon Nanostructured Counter Electrodes for Dye-Sensitized Solar Cells: A Review
    Samantaray MR, Mondal AK, Murugadoss G, Pitchaimuthu S, Das S, Bahru R, et al.
    Materials (Basel), 2020 Jun 19;13(12).
    PMID: 32575516 DOI: 10.3390/ma13122779
    This article provides an overview of the structural and physicochemical properties of stable carbon-based nanomaterials and their applications as counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). The research community has long sought to harvest highly efficient third-generation DSSCs by developing carbon-based CEs, which are among the most important components of DSSCs. Since the initial introduction of DSSCs, Pt-based electrodes have been commonly used as CEs owing to their high-electrocatalytic activities, thus, accelerating the redox couple at the electrode/electrolyte interface to complete the circuit. However, Pt-based electrodes have several limitations due to their cost, abundance, complicated facility, and low corrosion resistance in a liquid electrolyte, which further restricts the large-area applications of DSSCs. Although carbon-based nanostructures showed the best potential to replace Pt-CE of DSSC, several new properties and characteristics of carbon-CE have been reported for future enhancements in this field. In this review, we discuss the detailed synthesis, properties, and performances of various carbonaceous materials proposed for DSSC-CE. These nano-carbon materials include carbon nanoparticles, activated carbon, carbon nanofibers, carbon nanotube, two-dimensional graphene, and hybrid carbon material composites. Among the CE materials currently available, carbon-carbon hybridized electrodes show the best performance efficiency (up to 10.05%) with a high fill factor (83%). Indeed, up to 8.23% improvements in cell efficiency may be achieved by a carbon-metal hybrid material under sun condition. This review then provides guidance on how to choose appropriate carbon nanomaterials to improve the performance of CEs used in DSSCs.
    Matched MeSH terms: Corrosion
  3. Preparation and characterizations of oil palm fronds cellulose nanocrystal (OPF-CNC) as reinforcing filler in epoxy-Zn rich coating for mild steel corrosion protection
    Azani NFSM, Haafiz MKM, Zahari A, Poinsignon S, Brosse N, Hussin MH
    Int J Biol Macromol, 2020 Jun 15;153:385-398.
    PMID: 32145234 DOI: 10.1016/j.ijbiomac.2020.03.020
    Oil palm frond (OPF) is one of largest contributions to the biomass waste from oil palm plantation. In this work, OPF has been successfully utilized to prepare cellulose nanocrystal (OPF-CNC) by acid hydrolysis. OPF was initially treated with autohydrolysis treatment. The obtained OPF-CNC was characterized via complementary analyses. The produced OPF-CNC showed a high crystallinity index value (60%) and high BET surface area (26.10 m2 g-1) as compared to α-cellulose (crystallinity index: 54% and BET surface area:7.14 m2g-1). The surface analyses via scanning electron microscope (SEM) and transmission electron microscopy (TEM) demonstrated that the OPF-CNC has a smooth surface with a needle-like shape, where the average length and diameter are 95.09 nm and 6.81 nm, respectively. The corrosion analyses via electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PD) illustrate that the coated mild steel with the inclusion of 0.5 wt% OPF-CNC has managed to sharply reduce the corrosion (99%). The coated mild steel with the inclusion of 0.5 wt% OPF-CNC showed the highest hydrophobicity (100.5 ± 0.7°) and has lowest amount of O via water contact angle and energy dispersive X-ray spectroscopy (EDX) analyses respectively, indicating lowest corrosion rate.
    Matched MeSH terms: Corrosion
  4. Co-incorporation of graphene oxide/silver nanoparticle into poly-L-lactic acid fibrous: A route toward the development of cytocompatible and antibacterial coating layer on magnesium implants
    Bakhsheshi-Rad HR, Ismail AF, Aziz M, Akbari M, Hadisi Z, Khoshnava SM, et al.
    Mater Sci Eng C Mater Biol Appl, 2020 Jun;111:110812.
    PMID: 32279830 DOI: 10.1016/j.msec.2020.110812
    Magnesium (Mg) alloys present great potential for the development of orthopedic implants, whereas, their high degradation rate and poor antibacterial performance have restricted orthopedic applications. In this work, PLLA/GO-AgNP (poly-L-lactic acid/graphene oxide- silver nanoparticle) with different concentration of GO-AgNPs were deposited on Mg alloy via electrospinning method for enhancement of corrosion resistance and antibacterial performance. The result revealed that incorporation of GO into PLLA fibrous considerably slowed down the degradation rate of Mg alloy substrate and reduced the H2 release rate from the substrate. Also, co-incorporation of GO and AgNPs into PLLA fibrous resulted in substantial escalate in compressive strength after immersion in simulated body fluid (SBF). Antibacterial activity test exhibited that Mg alloy and neat PLLA fibrous presented minimal inhibition area toward Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). In contrast, using PLLA/GO-AgNPs fibrous improved antibacterial performance against both bacteria. Cytocompatibility results indicated that PLLA/GO-AgNPs fibrous with a low amount of GO-AgNPs enhanced cell proliferation and growth while high co-incorporation of GO-AgNPs showed a negative effect on cell proliferation. Taken together, PLLA/1GO-AgNPs fibrous coating shows suitable corrosion resistance, cytocompatibility, and antibacterial function for use in orthopedic applications.
    Matched MeSH terms: Corrosion
  5. Influence of Scanning on Nano Crystalline β-Ti Alloys Fabricated by Selective Laser Melting and Their Applications in Biomedical Science
    Yan L, Yu J, Zhong Y, Gu Y, Ma Y, Li W, et al.
    J Nanosci Nanotechnol, 2020 03 01;20(3):1605-1612.
    PMID: 31492322 DOI: 10.1166/jnn.2020.17340
    The present study focuses on the microstructural and bioactive properties evolution in selective laser melting (SLM) β titanium alloys. We have applied cross-scan strategy for improving mechanical properties and lower elastic modulus of SLMed Ti-20Mg-5Ta alloys which has been shown to be altering the microstructure and refining the grain size. The cross-scan strategy can refine the microstructure and induce various deformation textures in contrast to the conventional scan strategy. The microstructures of Ti-20Mg-5Ta alloys indicate that the cross-scan strategy will yield the best mechanical properties and lower elastic modulus. The corrosion behavior of the Ti-20Mg-5Ta alloys was studied during immersion in an acellular simulated body fluid (SBF) at 37±0.50 °C for 28 days. Both the mechanical and bioactive properties showed that the novel Ti-20Mg-5Ta alloys should be ideal for bone implants.
    Matched MeSH terms: Corrosion
  6. Bioresorbable Mg-Based Metastable Nano-Alloys for Orthopedic Fixation Devices
    Yan L, Zhang M, Wang M, Guo Y, Zhang X, Xi J, et al.
    J Nanosci Nanotechnol, 2020 03 01;20(3):1504-1510.
    PMID: 31492313 DOI: 10.1166/jnn.2020.17350
    This research has been accomplished using the advanced selective laser melting (SLM) technique as well as HIP post-treatment in order to improve mechanical properties and biocompatibility of Mg- Ca-Sr alloy. Through this research it becomes clearly noticeable that the Mg-1.5Ca-xSr (x = 0.6, 2.1, 2.5) alloys with Sr exhibited better mechanical properties and corrosion potentials. This is more particular with the Mg-1.5Ca-2.5Sr alloy after HIP post-treatment allowing it to provide a desired combination of degradation and mechanical behavior for orthopedic fracture fixation during a desired treatment period. In vivo trials, there was a clear indication and exhibition that this Mg-1.5Ca-2.5Sr alloy screw can completely dissolve in miniature pig's body which leads to an acceleration in growth of bone tissues. Mg-Ca-Sr alloy proved potential candidate for use in orthopedic fixation devices through Our results concluded that Mg-Ca-Sr alloy are potential candidate for use in orthopedic fixation devices through mechanical strength and biocompatibility evaluations (in vitro or In vivo).
    Matched MeSH terms: Corrosion
  7. Fulltext Synthesis, characterizations and anti-corrosion screening of Sadimine and Brosadamine
    Siti Noriah Mohd Shotor, Nur Anis Atirah Zulkiflee
    Journal of Academia Universiti Teknologi MARA Negeri Sembilan, 2020;8(2):1-8.
    MyJurnal
    This paper deals with a review of the inhibition activity of a Schiff bases on the deterioration of mild steel in hydrochloric acid media. Two Schiff base ligands namely N,N’- Bis(salicylidene) ethylenediamine (Sadimine) and N,N’-Bis(bromosalicylidene)- ethylenediamine (Brosadimine) were synthesized from the condensation reactions of salicylaldehyde or 5-bromosalicylaldehyde with ethylenediamine respectively and evaluated as corrosion inhibitor for mild steel in 1 M HCl solution using weight loss method. The use of inhibitors is one of the most practical methods for protection of mild steel against corrosion in acidic media. Schiff bases are widely being employed in such applications. This paper highlights the influence of structure–inhibition activity relationship of Schiff base compounds
    on their performance as corrosion inhibitors of mild steel in acid media. Sadimine and
    Brosadimine show appreciable corrosion inhibition efficiency against the corrosion of mild
    steel in 1 M HCl solution at room temperature. It has been found that Brosadimine shows
    greater corrosion inhibition efficiency than Sadimine due to extra halogen group presence in
    the structure. As the concentration of studied inhibitors increases, the corrosion inhibition
    efficiency of the prepared compounds also increases. This study demonstrated that corrosion
    inhibitors for metals and alloys can preserve the quality and life of metals from corrosion.
    Matched MeSH terms: Corrosion
  8. The Effect of H2S Pressure on the Formation of Multiple Corrosion Products on 316L Stainless Steel Surface
    Shah M, Ayob MTM, Rosdan R, Yaakob N, Embong Z, Othman NK
    ScientificWorldJournal, 2020;2020:3989563.
    PMID: 32774180 DOI: 10.1155/2020/3989563
    H2S gas when exposed to metal can be responsible for both general and localized corrosion, which depend on several parameters such as H2S concentration and the corrosion product layer formed. Therefore, the formation of passive film on 316L steel when exposed to H2S environment was investigated using several analysis methods such as FESEM and STEM/EDS analyses, which identified a sulfur species underneath the porous structure of the passive film. X-ray photoelectron spectroscopy analysis demonstrated that the first layer of CrO3 and Cr2O3 was dissolved, accelerated by the presence of H2S-Cl-. An FeS2 layer was formed by incorporation of Fe and sulfide; then, passivation by Mo took place by forming a MoO2 layer. NiO, Ni(OH)2, and NiS barriers are formed as final protection for 316L steel. Therefore, Ni and Mo play an important role as a dual barrier to maintain the stability of 316L steel in high pH2S environments. For safety concern, this paper is aimed to point out a few challenges dealing with high partial pressure of H2S and limitation of 316L steel under highly sour condition for the oil and gas production system.
    Matched MeSH terms: Corrosion
  9. Fulltext The Influence of Post Weld Heat Treatment Precipitation on Duplex Stainless Steels Weld Overlay towards Pitting Corrosion
    Sim BM, Hong TS, Hanim MA, Tchan EN, Talari MK
    Materials (Basel), 2019 Oct 10;12(20).
    PMID: 31658593 DOI: 10.3390/ma12203285
    Duplex stainless steels (DSSs) are complex materials and they have been widely used in the marine environment and gas industries, primarily offering a better resistance of pitting corrosion and good mechanical properties. In the present work, the effects of heat treatment on duplex stainless steel (DSS) weld overlay samples that were heat treated at three different temperatures, namely 350 °C, 650 °C, and 1050 °C, and followed by air cooling and water quenching were studied. Stress relief temperature at 650 °C had induced sigma phase precipitation in between delta ferrite and austenite (δ/γ) grain boundaries, resulting in the loss of corrosion resistance in the weld metal. Interestingly, post weld heat treatment (PWHT) test samples that were reheated to solution annealing temperature had shown no weight loss. The ferrite count determination in the region of weld metal overlay increased at hydrogen relief and decreased at stress relief temperatures due to slow cooling, which is more favorable to austenite formation. The amount of ferrite in the weld metals was significantly reduced with the increment of solution anneal temperature to 1050 °C because of sufficient time for the formation of austenite and giving optimum equilibrium fraction in the welds.
    Matched MeSH terms: Corrosion
  10. Fulltext Development of Nano-SiO2 and Bentonite-Based Mortars for Corrosion Protection of Reinforcing Steel
    Karunarathne VK, Paul SC, Šavija B
    Materials (Basel), 2019 Aug 17;12(16).
    PMID: 31426501 DOI: 10.3390/ma12162622
    In this study, the use of nano-silica (nano-SiO2) and bentonite as mortar additives for combating reinforcement corrosion is reported. More specifically, these materials were used as additives in ordinary Portland cement (OPC)/fly ash blended mortars in different amounts. The effects of nano-silica and bentonite addition on compressive strength of mortars at different ages was tested. Accelerated corrosion testing was used to assess the corrosion resistance of reinforced mortar specimens containing different amounts of nano-silica and bentonite. It was found that the specimens containing nano-SiO2 not only had higher compressive strength, but also showed lower steel mass loss due to corrosion compared to reference specimens. However, this was accompanied by a small reduction in workability (for a constant water to binder ratio). Mortar mixtures with 4% of nano-silica were found to have optimal performance in terms of compressive strength and corrosion resistance. Control specimens (OPC/fly ash mortars without any additives) showed low early age strength and low corrosion resistance compared to specimens containing nano-SiO2 and bentonite. In addition, samples from selected mixtures were analyzed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Finally, the influence of Ca/Si ratio of the calcium silicate hydrate (C-S-H) in different specimens on the compressive strength is discussed. In general, the study showed that the addition of nano-silica (and to a lesser extent bentonite) can result in higher strength and corrosion resistance compared to control specimens. Furthermore, the addition of nano-SiO2 can be used to offset the negative effect of fly ash on early age strength development.
    Matched MeSH terms: Corrosion
  11. Comparison of deep eutectic solvents (DES) on pretreatment of oil palm empty fruit bunch (OPEFB): Cellulose digestibility, structural and morphology changes
    Thi S, Lee KM
    Bioresour Technol, 2019 Jun;282:525-529.
    PMID: 30898410 DOI: 10.1016/j.biortech.2019.03.065
    In this work, a novel solvent, deep eutectic solvent (DES) was applied to examine its effectiveness in pretreating OPEFB. Three types of DESs, i.e. choline chloride-lactic acid (ChCl-LA), choline chloride-urea (ChCl-U) and choline chloride-glycerol (ChCl-G) were investigated. The pretreatment performance was based on cellulose digestibility, structural and morphology changes. At molar ratio of 1:2, ChCl-LA attained the highest reducing sugars yield of 20.7%, followed by ChCl-G (20.0%) and ChCl-U (16.9%). FT-IR and SEM results further confirmed the outstanding ability of ChCl-LA due of its ability in cellulose, hemicellulose and lignin disruption, exposing its cellulose fraction to enzymatic hydrolysis. ChCl-LA is also more favorable compare to acid and alkaline solvents as it could prevent sugars loss, use of expensive corrosion resistant equipment and ease products separation.
    Matched MeSH terms: Corrosion
  12. Dataset on optimization of EDM machining parameters by using central composite design
    Soundhar A, Zubar HA, Sultan MTBHH, Kandasamy J
    Data Brief, 2019 Apr;23:103671.
    PMID: 30788395 DOI: 10.1016/j.dib.2019.01.019
    Newly prepared titanium alloy (Ti-13Zr-13Nb (TZN)) using powder metallurgy is considered in this investigation. Titanium alloys (TZN) are used in hip and knee replacement for orthopedic implants. Conventional machining, TZN alloys produce higher tool wear rate and poor surface quality, but this can be reduced by Electrical Discharge Machining (EDM) method. Moreover, EDM produce good biological and corrosion resistant surface. In this research, experiments were conducted by considering the influential process factors such as pulse on time, pulse off time, voltage, and current. The experiments were designed based on Response Surface Methodology (RSM) of face centered central composite design. Analysis of Variance (ANOVA) was conducted to identify the significance process factors and their relation to output responses such as Electrode Wear Rate (EWR), Surface Roughness (SR) and Material Removal Rate (MRR). Further, an empirical model was developed by RSM in order to predict the output responses.
    Matched MeSH terms: Corrosion
  13. Fulltext Electrochemical data of single and hybrid sol-gel coating precursors for aluminum alloy corrosion protection in 3.5% NaCl
    Hussin MH
    Data Brief, 2019 Feb;22:971-976.
    PMID: 30740480 DOI: 10.1016/j.dib.2019.01.029
    The anti-corrosion performances of single(TEOS) and hybrid (APTES-TEOS) sol-gel coatings on Al alloy samples exposed to 3.5 wt% NaCl were evaluated employing electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The data acquired using the three corrosion analysis techniques were in accordance with each other where hybrid sol-gel coating offered the lowest corrosion rate and current density in comparison to the single precursor silanol coating. Tafel curves suggested that the hybrid silane coatings mitigate both the anodic and cathodic reactions simultaneously (mixed type inhibitor). These techniques justified that incorporation of hybrid sol-gel improved the Al corrosion protection performance considerably.
    Matched MeSH terms: Corrosion
  14. Fulltext Optimization of Micro and Nano Palm Oil Fuel Ash to Determine the Carbonation Resistance of the Concrete in Accelerated Condition
    Tang WL, Lee HS, Vimonsatit V, Htut T, Singh JK, Wan Hassan WNF, et al.
    Materials (Basel), 2019 Jan 03;12(1).
    PMID: 30609786 DOI: 10.3390/ma12010130
    The carbonation rate of reinforced concrete is influenced by three parameters, namely temperature, relative humidity, and concentration of carbon dioxide (CO₂) in the surroundings. As knowledge of the service lifespan of reinforced concrete is crucial in terms of corrosion, the carbonation process is important to study, and high-performance durable reinforced concretes can be produced to prolong the effects of corrosion. To examine carbonation resistance, accelerated carbonation testing was conducted in accordance with the standards of BS 1881-210:2013. In this study, 10⁻30% of micro palm oil fuel ash (mPOFA) and 0.5⁻1.5% of nano-POFA (nPOFA) were incorporated into concrete mixtures to determine the optimum amount for achieving the highest carbonation resistance after 28 days water curing and accelerated CO₂ conditions up to 70 days of exposure. The effect of carbonation on concrete specimens with the inclusion of mPOFA and nPOFA was investigated. The carbonation depth was identified by phenolphthalein solution. The highest carbonation resistance of concrete was found after the inclusion of 10% mPOFA and 0.5% nPOFA, while the lowest carbonation resistance was found after the inclusion of 30% mPOFA and 1.5% nPOFA.
    Matched MeSH terms: Corrosion
  15. Fulltext Titanium and titanium based alloys as metallic biomaterials in medical applications – spine implant case study
    Nur Azida Che Lah, Muhamad Hellmy Hussin
    Pertanika Journal of Science & Technology, 2019;27(1):459-472.
    MyJurnal
    Titanium (Ti) and Ti-based alloys presence the most widely applied as advanced biomaterials
    in biomedical implant applications. Moreover, these alloys are known to be the most
    valuable metallic materials including spinal cord surgical treatment. It becomes an interest
    due to its advantages compared to others, including its bio compatibility and corrosion
    resistant. However, an issue arises when it comes for permanent implant application as
    the alloy has a possible toxic effect produced from chemical reaction between body fluid
    environments with alloys chemical compositions. It also relies on the performance of
    neighbouring bone tissue to integrate with the implant surface. Abnormalities usually
    happen when surrounding tissue shows poor responses and rejection of implants that would
    leads to body inflammation. These cause an increase in foreign body reaction leading to
    severe body tissue response and thus, loosening of the implant. Corrosion effects and
    biocompatibility behaviour of implantation usage also become one of the reasons of
    implant damage. Here, this paper reviews the importance of using Ti and Ti-based alloys
    in biomedical implantation, especially in orthopaedic spinal cord injury. It also reviews the
    basic aspects of corrosion effects that lead to implant mechanical damage, poor response
    of body rejection and biocompatibility behaviour of implantation usage.
    Matched MeSH terms: Corrosion
  16. Fulltext Synthesis, biological evaluation and corrosion inhibition studies of transition metal complexes of Schiff base
    Kashyap S, Kumar S, Ramasamy K, Lim SM, Shah SAA, Om H, et al.
    Chem Cent J, 2018 Nov 20;12(1):117.
    PMID: 30460466 DOI: 10.1186/s13065-018-0487-1
    BACKGROUND: The transition metal complexes formed from Schiff base is regarded as leading molecules in medicinal chemistry. Because of the preparative availability and diversity in the structure of central group, the transition metals are important in coordination chemistry. In the present work, we have designed and prepared Schiff base and its metal complexes (MC1-MC4) and screened them for antimicrobial, anticancer and corrosion inhibitory properties.

    METHODOLOGY: The synthesized metal complexes were characterized by physicochemical and spectral investigation (UV, IR, 1H and 13C-NMR) and were further evaluated for their antimicrobial (tube dilution) and anticancer (SRB assay) activities. In addition, the corrosion inhibition potential was determined by electrochemical impedance spectroscopy (EIS) technique.

    RESULTS AND DISCUSSION: Antimicrobial screening results found complexes (MC1-MC4) to exhibit less antibacterial activity against the tested bacterial species compared to ofloxacin while the complex MC1 exhibited greater antifungal activity than the fluconazole. The anticancer activity results found the synthesized Schiff base and its metal complexes to elicit poor cytotoxic activity than the standard drug (5-fluorouracil) against HCT116 cancer cell line. Metal complex MC2 showed more corrosion inhibition efficiency with high Rct values and low Cdl values.

    CONCLUSION: From the results, we can conclude that complexes MC1 and MC2 may be used as potent antimicrobial and anticorrosion agents, respectively.

    Matched MeSH terms: Corrosion
  17. Fulltext Discharge Performance of Zinc-Air Flow Batteries Under the Effects of Sodium Dodecyl Sulfate and Pluronic F-127
    Hosseini S, Lao-Atiman W, Han SJ, Arpornwichanop A, Yonezawa T, Kheawhom S
    Sci Rep, 2018 Oct 08;8(1):14909.
    PMID: 30297883 DOI: 10.1038/s41598-018-32806-3
    Zinc-air batteries are a promising technology for large-scale electricity storage. However, their practical deployment has been hindered by some issues related to corrosion and passivation of the zinc anode in an alkaline electrolyte. In this work, anionic surfactant sodium dodecyl sulfate (SDS) and nonionic surfactant Pluronic F-127 (P127) are examined their applicability to enhance the battery performances. Pristine zinc granules in 7 M KOH, pristine zinc granules in 0-8 mM SDS/7 M KOH, pristine zinc granules in 0-1000 ppm P127/7 M KOH, and SDS coated zinc granules in 7 M KOH were examined. Cyclic voltammograms, potentiodynamic polarization, and electrochemical impedance spectroscopy confirmed that using 0.2 mM SDS or 100 ppm P127 effectively suppressed the anode corrosion and passivation. Nevertheless, direct coating SDS on the zinc anode showed adverse effects because the thick layer of SDS coating acted as a passivating film and blocked the removal of the anode oxidation product from the zinc surface. Furthermore, the performances of the zinc-air flow batteries were studied. Galvanostatic discharge results indicated that the improvement of discharge capacity and energy density could be sought by the introduction of the surfactants to the KOH electrolyte. The enhancement of specific discharge capacity for 30% and 24% was observed in the electrolyte containing 100 ppm P127 and 0.2 mM SDS, respectively.
    Matched MeSH terms: Corrosion
  18. Fulltext Ethanol as an electrolyte additive for alkaline zinc-air flow batteries
    Hosseini S, Han SJ, Arponwichanop A, Yonezawa T, Kheawhom S
    Sci Rep, 2018 Jul 26;8(1):11273.
    PMID: 30050161 DOI: 10.1038/s41598-018-29630-0
    Zinc-air flow batteries exhibit high energy density and offer several appealing advantages. However, their low efficiency of zinc utilization resulted from passivation and corrosion of the zinc anodes has limited their broad application. In this work, ethanol, which is considered as an environmentally friendly solvent, is examined as an electrolyte additive to potassium hydroxide (KOH) aqueous electrolyte to improve electrochemical performance of the batteries. Besides, the effects of adding different percentages of ethanol (0-50% v/v) to 8 M KOH aqueous electrolyte were investigated and discussed. Cyclic voltammograms revealed that the presence of 5-10% v/v ethanol is attributed to the enhancement of zinc dissolution and the hindrance of zinc anode passivation. Also, potentiodynamic polarization and electrochemical impedance spectroscopy confirmed that adding 5-10% v/v ethanol could effectively suppress the formation of passivating layers on the active surface of the zinc anodes. Though the addition of ethanol increased solution resistance and hence slightly decreased the discharge potential of the batteries, a significant enhancement of discharge capacity and energy density could be sought. Also, galvanostatic discharge results indicated that the battery using 10% v/v ethanol electrolyte exhibited the highest electrochemical performance with 30% increase in discharge capacity and 16% increase in specific energy over that of KOH electrolyte without ethanol.
    Matched MeSH terms: Corrosion
  19. Fulltext Experimental and theoretical studies of Schiff bases as corrosion inhibitors
    Jamil DM, Al-Okbi AK, Al-Baghdadi SB, Al-Amiery AA, Kadhim A, Gaaz TS, et al.
    Chem Cent J, 2018 Feb 05;12(1):7.
    PMID: 29404816 DOI: 10.1186/s13065-018-0376-7
    BACKGROUND: Relatively inexpensive, stable Schiff bases, namely 3-((4-hydroxybenzylidene)amino)-2-methylquinazolin-4(3H)-one (BZ3) and 3-((4-(dimethylamino)benzylidene)amino)-2-methylquinazolin-4(3H)-one (BZ4), were employed as highly efficient inhibitors of mild steel corrosion by corrosive acid.

    FINDINGS: The inhibition efficiencies were estimated based on weight loss method. Moreover, scanning electron microscopy was used to investigate the inhibition mechanism. The synthesized Schiff bases were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy and micro-elemental analysis. The inhibition efficiency depends on three factors: the amount of nitrogen in the inhibitor, the inhibitor concentration and the inhibitor molecular weight.

    CONCLUSIONS: Inhibition efficiencies of 96 and 92% were achieved with BZ4 and BZ3, respectively, at the maximum tested concentration. Density functional theory calculations of BZ3 and BZ4 were performed to compare the effects of hydroxyl and N,N-dimethylamino substituents on the inhibition efficiency, providing insight for designing new molecular structures that exhibit enhanced inhibition efficiencies.

    Matched MeSH terms: Corrosion
  20. Bio-corrosion behavior and mechanical characteristics of magnesium-titania-hydroxyapatite nanocomposites coated by magnesium-oxide flakes and silicon for use as resorbable bone fixation material
    Khalajabadi SZ, Abu ABH, Ahmad N, Yajid MAM, Hj Redzuan NB, Nasiri R, et al.
    J Mech Behav Biomed Mater, 2018 Jan;77:360-374.
    PMID: 28985616 DOI: 10.1016/j.jmbbm.2017.09.032
    This study was aimed to improve of the corrosion resistance and mechanical properties of Mg/15TiO2/5HA nanocomposite by silicon and magnesium oxide coatings prepared using a powder metallurgy method. The phase evolution, chemical composition, microstructure and mechanical properties of uncoated and coated samples were characterized. Electrochemical and immersion tests used to investigate the in vitro corrosion behavior of the fabricated samples. The adhesion strength of ~36MPa for MgO and ~32MPa for Si/MgO coatings to substrate was measured by adhesion test. Fabrication a homogenous double layer coating with uniform thicknesses consisting micro-sized particles of Si as outer layer and flake-like particles of MgO as the inner layer on the surface of Mg/15TiO2/5HA nanocomposite caused the corrosion resistance and ductility increased whereas the ultimate compressive stress decreased. However, after immersion in SBF solution, Si/MgO-coated sample indicates the best mechanical properties compared to those of the uncoated and MgO-coated samples. The increase of cell viability percentage of the normal human osteoblast (NHOst) cells indicates the improvement in biocompatibility of Mg/15TiO2/5HA nanocomposite by Si/MgO coating.
    Matched MeSH terms: Corrosion
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