scholarly journals NanoZnO-modified titanium implants for enhanced anti-bacterial activity, osteogenesis and corrosion resistance

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Zheng Wang ◽  
Xiaojing Wang ◽  
Yingruo Wang ◽  
Yanli Zhu ◽  
Xinqiang Liu ◽  
...  

AbstractTitanium (Ti) implants are widely used in dentistry and orthopedics owing to their excellent corrosion resistance, biocompatibility, and mechanical properties, which have gained increasing attention from the viewpoints of fundamental research and practical applications. Also, numerous studies have been carried out to fine-tune the micro/nanostructures of Ti and/or incorporate chemical elements to improve overall implant performance. Zinc oxide nanoparticles (nano-ZnO) are well-known for their good antibacterial properties and low cytotoxicity along with their ability to synergize with a variety of substances, which have received increasingly widespread attention as biomodification materials for implants. In this review, we summarize recent research progress on nano-ZnO modified Ti-implants. Their preparation methods of nano-ZnO modified Ti-implants are introduced, followed by a further presentation of the antibacterial, osteogenic, and anti-corrosion properties of these implants. Finally, challenges and future opportunities for nano-ZnO modified Ti-implants are proposed. Graphical Abstract

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Wensheng Fu ◽  
Yufang Luo ◽  
Jingjin Tan ◽  
Bohan Jiang

Abstract: Magnesium (Mg) alloy is the lightest metal material found because of its excellent physical and mechanical properties, specific strength, biocompatibility and biomechanical compatibility, therefore, it has very promising development prospects in aerospace, automobile manufacturing, and biodegradable materials. However, due to the relatively chemical properties of magnesium alloys, poor corrosion resistance, fast degradation rate, and poor wear resistance, they have been greatly restricted in practical applications. Therefore, anti-corrosion measures of magnesium alloys are particularly important. The manufacture of hydrophobic surfaces is a very effective method of anti-corrosion. The surface of super-hydrophobic polymer composites (i.e., thin coatings) is constructed on the surface of magnesium alloy materials to enhance their corrosion resistance and wear resistance, and the effect of its antiseptic measures is very impressive.


Author(s):  
Jian Huang ◽  
Peilin Wang ◽  
Kaifa Du ◽  
Huayi Yin ◽  
Dihua Wang

Abstract The exploration of efficient preparation methods and corrosion-resistant medium entropy alloys (MEAs) has attracted significant attentions in recent years. In this paper, powdery Fe0.5CoNiCuSnx (x=0, 0.05, 0.08, and 0.1) MEAs were prepared by the one-step electrochemical reduction of metal oxides in molten Na2CO3-K2CO3 using a Ni11Fe10Cu oxygen-evolution inert anode. The effects of Sn on the structures, morphologies, and corrosion behaviors of the prepared MEAs were systematically investigated. The electrolytic MEAs exhibited a single face-centered cubic phase at x≤0.05, and the CuSn-rich phase would be segregated in the alloys at 0.08≤x≤0.1. Moreover, increasing Sn reduced the particles size of MEAs, and Sn improved the corrosion resistance of MEAs in 0.5 M H2SO4, 1 M KOH, and 3.5% NaCl solutions. The electrolytic MEA(Sn0.05) exhibited the best corrosion resistance, which had the corrosion current densities of 3.7×10-5 A/cm2 (0.5 M H2SO4), 1.2×10-5 A/cm2 (1 M KOH), and 1.6×10-5 A/cm2 (3.5 wt% NaCl) at room temperature. Overall, this paper not only provides a green approach to preparing Sn-containing MEAs, but also offers an efficient way to control structures and morphologies, thereby improving the corrosion resistance.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1762
Author(s):  
Artur Maciej ◽  
Natalia Łatanik ◽  
Maciej Sowa ◽  
Izabela Matuła ◽  
Wojciech Simka

One method of creating a brass coating is through electrodeposition, which is most often completed in cyanide galvanic baths. Due to their toxicity, many investigations focused on the development of more environmentally friendly alternatives. The purpose of the study was to explore a new generation of non-aqueous cyanide-free baths based on 1-ethyl-3-methylimidazolium acetate ionic liquids. The study involved the formation of copper, zinc, and brass coatings. The influence of the bath composition, cathodic current density, and temperature was determined. The obtained coatings were characterized in terms of their morphology, chemical composition, phase composition, roughness, and corrosion resistance. It was found that the structure of the obtained coatings is strongly dependent on the process parameters. The three main structure types observed were as follows: fine-grained, porous, and olive-like. To the best knowledge of the authors, it is the first time the olive-like structure was observed in the case of an electrodeposited coating. The Cu-Zn coatings consisted of 19–96 at. % copper and exhibited relatively good corrosion resistance. A significant improvement of corrosion properties was found in the case of copper and brass coatings with the olive-like structure.


Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 606
Author(s):  
Linchun Zhang ◽  
Ailian Zhang ◽  
Ke Li ◽  
Qian Wang ◽  
Junzhe Liu ◽  
...  

The electrical resistance and polarization effect of cement paste containing reinforcement were tested to research the anti-corrosion properties of steel bars in cement paste. Moreover, the microstructure and composition of passivation film and rust on the steel bars were studied. The water–cement ratio of the cement paste in this study was 0.3, with 0.5% NaCl, 1% NaNO2, and 1% Benzotriazole, and an assembly unit of 0.5% NaNO2 + 0.5% Benzotriazole by mass of cement was added to the cement to provide a chloride environment. X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) were applied to research the composition of the passivation film and the microstructure of the cement paste, respectively. The results indicated that the samples with the assembly unit of 0.5% NaNO2 + 0.5% Benzotriazole showed the highest electrical resistance and polarization electrical resistance, while the specimens with 1.0% Benzotriazole showed the lowest electrical resistance and polarization electrical resistance. Moreover, the passivation film of steel bars weakened with increasing distance from the surface of the steel bars. Therefore, the corrosion of steel bars becomes more serious with increasing distance. Finally, the influence of the rust inhibitor on the corrosion resistance of steel bars in the specimens decreased in the following order: 0.5% NaNO2 + 0.5% Benzotriazole >1.0% NaNO2>1.0% Benzotriazole.


2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110294
Author(s):  
Khaled Abd El-Aziz ◽  
Emad M Ahmed ◽  
Abdulaziz H Alghtani ◽  
Bassem F Felemban ◽  
Hafiz T Ali ◽  
...  

Aluminum alloys are the most essential part of all shaped castings manufactured, mainly in the automotive, food industry, and structural applications. There is little consensus as to the precise relationship between grain size after grain refinement and corrosion resistance; conflicting conclusions have been published showing that reduced grain size can decrease or increase corrosion resistance. The effect of Al–5Ti–1B grain refiner (GR alloy) with different percentages on the mechanical properties and corrosion behavior of Aluminum-magnesium-silicon alloy (Al–Mg–Si) was studied. The average grain size is determined according to the E112ASTM standard. The compressive test specimens were made as per ASTM: E8/E8M-16 standard to get their compressive properties. The bulk hardness using Vickers hardness testing machine at a load of 50 g. Electrochemical corrosion tests were carried out in 3.5 % NaCl solution using Autolab Potentiostat/Galvanostat (PGSTAT 30).The grain size of the Al–Mg–Si alloy was reduced from 82 to 46 µm by the addition of GR alloy. The morphology of α-Al dendrites changes from coarse dendritic structure to fine equiaxed grains due to the addition of GR alloy and segregation of Ti, which controls the growth of primary α-Al. In addition, the mechanical properties of the Al–Mg–Si alloy were improved by GR alloy addition. GR alloy addition to Al–Mg–Si alloy produced fine-grained structure and better hardness and compressive strength. The addition of GR alloy did not reveal any marked improvements in the corrosion properties of Al–Mg–Si alloy.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2621
Author(s):  
Aneta Bartkowska

The paper presents the results of a study of the microstructure, chemical composition, microhardness and corrosion resistance of Cr-B coatings produced on Vanadis 6 tool steel. In this study, chromium and boron were added to the steel surface using a laser alloying process. The main purpose of the study was to determine the impact of those chemical elements on surface properties. Chromium and boron as well as their mixtures were prepared in various proportions and then were applied on steel substrate in the form of precoat of 100 µm thickness. Depending on the type of precoat used and laser processing parameters, changes in microstructure and properties were observed. Coatings produced using precoat containing chromium and boron mixture were characterized by high microhardness (900 HV0.05–1300 HV0.005) while maintaining good corrosion resistance. It was also found that too low laser beam power contributed to the formation of cracks and porosity.


2021 ◽  
Vol 35 ◽  
pp. 205873842110005
Author(s):  
Xia Ma ◽  
Meng Yang ◽  
Yan He ◽  
Chuntao Zhai ◽  
Chengliang Li

Tremella polysaccharide is known to be structurally unique and biologically active natural products, abundant and versatile in activities and applications in food industry, daily chemical industry and medicine industry. In order to improve the industrialisation of Tremella polysaccharide, the limitations of preparation and structure-activity relationship of Tremella polysaccharide were reviewed in this paper. The research progress of Tremella polysaccharide in the past 20 years was summarized from the sources, preparation methods, molecular structure, activity and application, and the research trend in the future was also prospected. The application prospect of Tremella polysaccharide in against multiple sub-health states was worth expecting.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Yingjie Yang ◽  
Yanhui Yu ◽  
Jing Li ◽  
Qingrong Chen ◽  
Yanlian Du ◽  
...  

AbstractThe investigation of highly effective, durable, and cost-effective electrocatalysts for the hydrogen evolution reaction (HER) is a prerequisite for the upcoming hydrogen energy society. To establish a new hydrogen energy system and gradually replace the traditional fossil-based energy, electrochemical water-splitting is considered the most promising, environmentally friendly, and efficient way to produce pure hydrogen. Compared with the commonly used platinum (Pt)-based catalysts, ruthenium (Ru) is expected to be a good alternative because of its similar hydrogen bonding energy, lower water decomposition barrier, and considerably lower price. Analyzing and revealing the HER mechanisms, as well as identifying a rational design of Ru-based HER catalysts with desirable activity and stability is indispensable. In this review, the research progress on HER electrocatalysts and the relevant describing parameters for HER performance are briefly introduced. Moreover, four major strategies to improve the performance of Ru-based electrocatalysts, including electronic effect modulation, support engineering, structure design, and maximum utilization (single atom) are discussed. Finally, the challenges, solutions and prospects are highlighted to prompt the practical applications of Ru-based electrocatalysts for HER.


2021 ◽  
Vol 105 (1) ◽  
pp. 329-337
Author(s):  
David Kusmič ◽  
Lenka Klakurková ◽  
Martin Julis ◽  
Pavel Gejdoš ◽  
Jindrich Vilis ◽  
...  

In this paper, commercially cold-rolled and artificial aged EN AW 7075 T6 alloy has been used. To ensure increased corrosion resistance, surface hardness, scratching resistance, and aesthetic features, this aluminium alloy was subsequently hard anodised and hot-water sealed (AC-A). The hard anodizing and sealing process increased surface hardness up to 304±13 HV 1 from an initial surface hardness of 194±3 HV 1. Also, the microhardness of the anodised layer and bulk material has been documented. Scanning electron microscopy (SEM) was used for microstructure and trapped precipitates investigation in the 42.9±1.4 thick formed anodised layer investigation. The T6 treated (AC) and hard anodised together with sealed (AC-A) EN AW 7075 alloy corrosion properties were evaluated using the anodic potentiodynamic polarisation tests (PPT) in a neutral 2.5% NaCl deaerated solution. The corrosion rate CR (mm/y) decreased approx. 39-times for the hard anodised and sealed EN AW 7075 alloy (AC-A), associated with the shift of the Ecorr (mV) to more positive values, degreased Icorr (µA) and increased Rp (Ohm) values compared to the artificial aged (AC) alloy. Additionally, the pitting was evaluated using laser confocal microscopy, and the pitting coefficient was also calculated.


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