Papers by Keyword: Zinc

Abstract: Infant malnutrition remains a major health problem in West Africa, particularly among children aged 6 months, the crucial period for dietary diversification. Faced with the predominance of imported industrial flours, which are often expensive, local populations are turning to traditional flours. To improve the nutritional quality of these flours, food fortification, recommended by bodies such as the FAO and the WFP, is commonly used. In this study, the mixture design method was used to formulate an affordable complementary flour, enriched in iron, zinc and vitamin C, from under-exploited local plant resources such as Anacardium occidentale kernel fragments and Parkia biglobosa pulp. An augmented centred mixing design with constraints was used to formulate, model and optimise the iron, zinc and vitamin C content of the infant supplement flour. Modelling of the iron content revealed a synergistically interacting cubic model with a desirability of 0.97, and an average iron content of 14.13 mg/100 g. Zinc content was estimated at 5.78 mg/100 g and modelled by a significant quadratic model. The vitamin C content was better represented by a linear model with a synergistic interaction, with a desirability of 0.97 and an average content of 117.6 mg/100 g, well above the standard of 30 mg/100 g. In conclusion, the optimisation has maximised the iron, zinc and vitamin C content of the formulation, offering an improved nutritional solution for combating infant malnutrition.

Abstract: Acesulfame, with its oxathiazinone ring and potential coordination sites, acts as a ligand in forming complexes with various metal ions. According to this point, this study includes the synthesis and characterization of novel zinc(II) complexes incorporating acesulfame (acs) with various thione-containing ligands: 2-mercaptobenzothiazole (bztSH), 2-mercapto-benzimidazole (bizmSH), 2-mercaptobenzoxazole (bzoxSH), 1,3-dihydro-2H-imidazole-2-thione (imSH), and 5-(p-tolyl)oxazole-2(3H)-thione (mphtSH). The synthesized complexes, identified as [Zn(acs)₂(bztSH)₂] (1), [Zn(acs)₂(bizmSH)₂] (2), [Zn(acs)₂(bzoxSH)]₂ (3), [Zn(acs)₂(imSH)₂] (4), and [Zn(mphtS)₂] (5), were structurally elucidated using CHN analysis, nuclear magnetic resonance (NMR) spectroscopy, infrared (IR) spectroscopy, and molar conductivity measurements. Results indicate that the acesulfame ligand coordinates as a monodentate ligand via its nitrogen atom in complexes (1-4). In complex (1), the bztSH ligand coordinates in a monodentate mode through the nitrogen atom of its heterocyclic ring. Conversely, in complexes (2) and (4), bizmSH and imSH coordinate as monodentate ligands via their sulfur atoms. Complex (3) is a binuclear species where bzoxSH coordinates as a bidentate ligand through both its nitrogen and sulfur atoms. Notably, in complex (5) , the mphtSH ligand displaces acesulfame, coordinating as a bidentate ligand through its nitrogen and sulfur atoms. Furthermore, the antibacterial activities of these complexes were evaluated against Staphylococcus aureus and Escherichia coli. Complexes (4) and (1) demonstrated the highest efficacy. The [Zn(acs)₂(imSH)₂] (4) exhibited inhibition efficiencies of 74% and 79% with inhibition zones of 20 mm and 23 mm against S. aureus and E. coli, respectively. Similarly, [Zn(acs)₂(bztSH)₂] (1) showed inhibition efficiencies of 70% and 76% with inhibition zones of 19 mm and 22 mm against S. aureus and E. coli, respectively.

Abstract: Phosphate invert glasses are mainly composed of ortho-and pyro-phosphate units and can stimulate cellular functions by releasing inorganic ions. Our group has succeeded in the synthesis of titanium-containing phosphate invert glasses with the liquid phase method at room temperature. ZnO is classified as an intermediate oxide in the glass network structure and improves the chemical durability of phosphate invert glasses. In addition, zinc ion exhibit a wide range of antibacterial ability. However, excess amounts of zinc ions can be toxic to cells. Hence, the dissolution behavior of zinc ions must be controlled for biomedical applications. In this work, ZnO-containing phosphate invert glasses (PIG-Zn) were prepared using the liquid phase method. The phosphate groups of PIG-Zn were composed of ortho-and pyro-phosphate groups, and the peaks were blue-shifted with increasing the ZnO content due to the field strength of Zn²⁺ being larger than that of Ca²⁺. Thus, phosphate groups may be cross-linked by Zn²⁺ to form P-O-Zn bonds. Meanwhile, ion-releasing amounts from PIG-Zn were decreased with increasing ZnO content. This is because the formation of P-O-Zn bonds can increase the chemical durability of PIG-Zn. In addition, PIG-Zn showed excellent antibacterial ability. Therefore, PIG-Zn is expected to exhibit antibacterial ability with controlled Zn²⁺ ion-releasing behavior for biomedical applications.

Abstract: The noise and vibrations generated by equipment and machinery during everyday life and industrial activities can affect both human and machine operations. Specifically, research aimed at suppressing vibrations and noise to enhance the energy efficiency of machinery is becoming increasingly active. In this study, magnesium was selected as the material for vibration damping. The detrimental effects of magnesium are improved by the addition of small amounts of Mn and Zn. A composite material was fabricated using magnesium, which has excellent vibration damping properties, and carbon steel (S45), which has superior mechanical properties. Magnesium alloys with Zn additions of 1, 3, and 5 wt.% were produced to enhance the corrosion resistance and strength of magnesium. Contact angle experiments were conducted to measure the wettability of the magnesium alloys. The contact angle was measured using the sessile drop method. The magnesium alloys showed a decreasing trend in contact angle with increasing zinc content. To explain the decrease in contact angle in Mg-Zn alloys, microstructure and compositional analyses were performed. First, Mg-Fe and Zn-Fe phase diagrams were investigated. The Mg-Fe system was found to contain no intermetallic compounds. In Zn-Fe interactions, Zn appears to form a metallic bond with Fe. The presence of the Γ phase at the interface between the magnesium alloy and S45 indicates that Zn has diffused from the magnesium alloy into both the magnesium alloy and S45. The Γ phase, considered a compound of Fe₃Zn₁₀, improves wettability between particles due to the formation of intermetallic compounds. Therefore, it was inferred that the wettability of the magnesium alloy improved. Additionally, improved wettability is expected to contribute to better adhesion processes and potentially increase interfacial shear strength.

Abstract: Aluminum-Air Batteries (AABs) are considered to be an attractive candidate as a energy storage technology due to their abundant raw material availability, high theoretical capacity, energy density, and safety. However, the development of these batteries is hindered by limited energy efficiency, primarily due to the high rate of self-corrosion of the aluminum anode in alkaline solutions, both under open-circuit conditions and during battery discharge. This research aims to enhance the performance of aluminum anodes in AABs by using commercials aluminum alloys as anodes and modifying their surfaces through the electrodeposition of zinc and manganese (Zn-Mn). The electrolyte used in this AAB is an alkaline solution consist of KOH 4M with 0,2M ZnO and 100mg/L CTAB as additive. The results show that electrodeposition was successfully conducted, leading to reduced corrosion rate as observed in linear polarization tests. Furthermore, electrodeposition contributed to increase battery cycle life, capacity discharge and energy discharge, as demonstrated by charge-discharge tests.

Abstract: The present research proposes the comparison of chitosan zinc nanocomposites in the form of membranes and hydrogels. Three concentrations (0.2, 0.4, and 0.6 wt%) of zinc (Zn) nanoparticle inclusion were used to create the chitosan nanocomposites for enhanced biological applications. Statistical analysis was performed with sample size N=16, an alpha error of 0.5, 95% confidence interval (CI), and G-power at 80%, The nanocomposite variations were analyzed for their improved capabilities against chitosan for its antibacterial activity (mm), water uptake (%), and other visual parameters including SEM and FTIR. Independent T-test through SPSS software revealed that both nanocomposites were statistically significant with (p = 0.01, p<0.05) and (p=0.026, (p>0.05)). The current study proposes novel chitosan with zinc nanocomposites with enhanced biological activity and offers a future scope for improved biomedical applications.

Abstract: Aluminum (Al) has emerged to become one of the potential anode materials candidates in metal-based batteries due to its abundant resource, inexpensive cost, good safeness and high theoretical energy density. However, thoughtful challenges have been barrier towards huge progress, including easy aluminum hydroxide formation, low practical voltage, and high corrosion rate. To approach those problems, this article proposes to enhance the electrochemical performance of anode side through electrodeposition of Zn-Mn on aluminum surface. The deposition of Zn-Mn consists of citrate and ethylenediaminetetraacetic acid (EDTA) as complexing agent to control the process rate. The effect of various deposition time, 0, 10, and 30 minutes, will be investigated by linear polarization, linear sweep voltammetry, cyclic voltammetry, and electrochemical impedance spectroscopy measurements. The electrochemical measurement exhibits the deposition effect, minimized the impedance of Al surface and improved the electrochemical reactions. Moreover, the appearance of Zn-Mn layer has prolonged the discharge performance with battery analyzer measurements. Therefore, energy density increased from 1270.52 to 3327.68 mWh g^-1Al and the specific capacity enhances from 2779.908 to 7291.651 mAh g^-1. All the measurements applied 3.5% sodium chloride (NaCl). These results pose the electrical performance enhancement from the anode side, but the development of other sides is also necessary.

Abstract: The potentiodynamic polarization method has investigated the corrosion behavior of zinc metal in 3.5% NaOH with a variation of bee wax popolis extract (BWPE) inhibitor, variation of immersion time, and temperature. Zinc plates were tested at 150 °C and 200 °C with immersion durations of 2, 4, and 6 hours, respectively. The variation of inhibitor concentration on corrosion rate has also been studied from 0, 200, 400, 600, 800, and 1000 ppm, followed by testing temperature variations of 25, 35, and 45°C for optimal inhibitor concentration. It is expected that this research will contribute to alternative organic corrosion inhibitors. Tafel polarization test results demonstrated that the corrosion rate of zinc metal in 3% NaOH increased with increasing test temperature and immersion time. Increasing the concentration of BWPE inhibitor from 200 ppm to 1000 ppm can reduce the corrosion rate of zinc metal from the sample without blank with optimal inhibition effectiveness obtained at a concentration of 800 ppm by 46.16%

Abstract: Zinc has attracted significant attention in research due to its cost-effective use as an electrodeposited material, effectively protecting various types of steel from corrosion and wear. However, despite its advantages, zinc has limitations in fully guarding steel against corrosion. Recent studies propose that blending zinc with other metals during the coating process can proficiently shield mild steel from deterioration. The motivation for this study stems from recognizing the restrictions of zinc electrodeposition and the limited exploration of zinc multi-facet composite coatings for mild steel. In this study, the electrodeposition technique was employed to apply a coating to mild steel using zinc and nanoparticles of calcium oxide (CaO) and manganese oxide (MnO₂). The coating bath's chemical composition included mass variations of 0-12 g/L for CaO and MnO₂, along with 10 g/L each of boric acid, thiourea, and Na₂SO₄, and 15 g/L of K₂SO₄ and ZnSO₄. The coating process occurred over a twenty-minute period, with a pH of 4.8, voltage set at 3.2V, current density at 1 A/cm², temperature at 47°C, and stirring rate at 200 rpm. Results obtained from the coated mild steel demonstrated that Zn-6CaO-6MnO₂ exhibited the greatest coating thickness at 0.2308 mm, and it showcased impressive corrosion resistance at 2.0618 mm/year. The Zn-CaO-MnO₂ coating displayed a substantial deposit of crystallites in its microstructure, assisted by the presence of manganese, contributing to a smoother surface texture.

Abstract: This study aims to analysized the effect of addition doped metal (Ti and Zn) on NASICON structure to morphology, materials structure, and electrochemical performance especially ionic conductivity properties. NASICON is a sodium super ionic conductor that it could be as solid electrolyte batteries. One of the problems that exist in the secondary battery is the low working temperature of the electrolyte, which makes it easy to explode when exposed to free air. The common electrolyte in liquid phase, so NASICON as replacement alternative. The synthesis method used is the solid-state reaction method by mixing sodium carbonate, silicon dioxide, zirconium oxide, ammonium dihydrogen phosphate, doped metal (titanium oxide and zinc oxide) and some anhydrous ethanol into a planetary ball mill, dried then calcined. Then the material is pressed to produce pellets and the sintered. The doping used varies from 0 to 5 mol% of titanium and zinc. XRD results showed that all variations in titanium doped had found rhombohedral and monoclinic. whereas in zinc doping also have those phase. The highest ionic conductivity is 7.8x10^-3 S/m on 2% mol Zinc Addition