Addition Of Ag Research Articles

Advancing self‐healing soy protein hydrogel with dynamic Schiff base and metal‐ligand bonds for diabetic chronic wound recovery

AbstractTo address the unique challenges of diabetic wound healing, wound dressings, particularly multifunctional hydrogels have garnered considerable interest. For the first time, a novel environmentally friendly soy protein‐based hydrogel is developed to accelerate the healing of diabetic chronic wounds. Specifically, this hydrogel framework is in direct formation through the dynamic Schiff base between oxidized guar gum and epigallocatechin‐3‐gallate (EGCG)‐modified soy protein isolate. Meantime, the addition of Ag+ enhances the cross‐linking of the hydrogel network by forming metal‐ligand bonds with the catechol groups in EGCG. Interestingly, the stretchability (up to 380%), swelling, and rheology properties of the hydrogel can be controlled by fine‐tuning the density of metal‐ligand bonds, endowing them with a high potential for precise matching. Additionally, various dynamic bonds endow hydrogel with excellent self‐healing ability, adhesiveness, and injectability. This hydrogel also exhibits good antibacterial properties, biocompatibility, and cell migration capabilities. Both in vivo and in vitro experiments demonstrated the outstanding anti‐inflammatory capacity of the hydrogel and its ability to modulate macrophage polarization. Consequently, the hydrogel has proven effective in promoting wound healing in a diabetic full‐thickness wound model through enhanced angiogenesis and collagen deposition. This eco‐friendly plant protein hydrogel offers a sustainable solution for wound care and environmental protection.

The effect of Silver addition and deformation parameters on mechanostructure, biodegradation, antimicrobial and mechanical properties of Zn-based biodegradable alloys.

Although low mechanical properties, Zinc (Zn) alloy systems with Copper (Cu) and Silver (Ag) as alloying elements have strong biocompatibility and biodegradability characteristics. This study examined the effects of rolling parameters and Ag alloying on the mechanical, biodegradable, and final structure of an alloy based on Zn. Comparing treated and untreated specimens, the addition of Ag led to a considerable improvement in both hardness and compressive strength. The produced alloys with varying amounts of Ag (between 1 and 4wt%) were cold rolled at 400-800r/min and friction coefficients between 0.3 and 0.5. The alloys' ultimate strength rose with an increase in rolling speed for Zn1Cu4Ag, and hardness and compressive strengths rose to 80HV and 470MPa, respectively. It was demonstrated that rolling force rose somewhat with Ag concentration but significantly increased with rolling speed and friction. E. Coli and S. aureus were used to assess the biodegradable alloys' antibacterial properties. For the Zn-1Cu-2Ag alloy, the inclusion of Ag resulted in a considerable (50%) rise in antibacterial activity that exceeded the effects seen in other alloy systems.

Investigation on the interface properties of Be-Al alloys via first-principles calculation

In this paper, the Be/Al pure interface is constructed using First-principles calculation. Among the six interface structures, the interface adhesion work calculation results show that the Be (001)/Al (100) interface has the largest adhesion work (2.48 J/m2), which proves that the Be (001)/Al (100) interface is the most stable interface structure. Also, the Be (001)/Al (100) composite interface structure doping elements of Ni, Ag, Co and Ge was constructed. The results of segregation heat and interface adhesion work calculation showed that the addition of Ni, Ag and Co was beneficial to the improvement of the Be (001)/Al (100) interface strength. The doping effect of Ag and Co is similar, followed by Ni, and the doping of Ge leads to the degradation of interface properties. The calculation results of the partial density of states (PDOS) and the charge density difference show that in the pure Be (001)/Al (100) interface structure, a metallic bond is formed between Be and Al atoms near the interface. With the introduction of doping elements, the charge between Be and Al atoms is redistributed. A stronger new metal bond of Be-X or Al-X (X=Ni, Ag, Co) is formed, but the doping of Ge elements forms a weaker Be-Ge metal bond, which is not conducive to the performance improvement of Be-Al alloys.

Cape Gooseberry (Physalis peruviana L.) Volatile Compounds Determination by Vacuum-Assisted Sorbent Extraction (VASE)-Selected Aspects.

Vacuum-Assisted Sorbent Extraction (VASE) is a novel extraction technique that uses vacuum to facilitate the transfer of volatile compounds from the matrix to the sorbent. This technique was explored for extraction of volatiles from cape gooseberry fruit, for both qualitative and quantitative analyses. Selected extraction parameters were tested: sample size, extraction temperature and time, influence of tissue disintegration on release of volatiles, and also addition of Ag+1 ions in the form of AgNO3 to stop enzymatic formation of volatile compounds. For selected conditions (10 g sample, extraction for 30 min. at 40 °C of volatiles from blended fruit) quantitative aspects were explored. Twenty-two compounds of cape gooseberry were tested. The method was characterized with a very good linearity in a range of 10-5000 µg/kg and good reproducibility. The experiments proved the usefulness of VASE in both volatile profiling and quantitative analyses of cape gooseberry and in prospective other fruit.

Cold sprayed Ta-Ag composites: Mechanistic insight into enhanced corrosion resistance and antibacterial ability

In this work, cold spray was used to produce Ta-xAg metal matrix composites (MMCs). The addition of Ag prevents Ta matrix from corrosion and simultaneously induces excellent antibacterial ability. Additionally, varied soft Ag volumes in feedstock powder led to a synergistic deposition phenomenon, profoundly affecting Ag dissolution and correlated antibacterial performance via a microstructural mechanism. Taking advantage of it, a robust antibacterial ability can be facilitated by minimal Ag usage.

Revisiting Ag addition in 7xxx aluminum alloys: Insights into its impact on the microstructure and properties of an Al-Zn-Mg-Cu-Zr alloy with a Zn/Mg ratio of 4

In this study, the influence of minor Ag addition on the microstructure, mechanical and corrosion properties of an Al-Zn-Mg-Cu-Zr (7449) alloy with Zn/Mg ratio of 4 was systematically investigated using various materials characterization techniques, Slow Strain Rate Test (SSRT), Potentiodynamic Polarization (PDP) and Intergranular Corrosion (IGC) measurements. Microstructure characterization by Scanning Electron Microscopy (SEM) and Differential Scanning Calorimetry (DSC) showed that Ag partitioning in the eutectic Mg(Zn,Cu,Al)2 phase occurs resulting in an increase in its solvus line. After processing to the T4 condition, Ag was partially in solid solution with the excess forming an Ag-rich AlAgZnMgCu phase. Scanning-Transmission Electron Microscopy (STEM) showed evidence of quench-induced η-Mg(Zn,Cu,Al)2 precipitates at the grain boundaries (GBs) in the T4 condition with ∼3 at.% Ag in the Ag-modified alloy. STEM and Atom Probe Tomography (APT) confirmed that ∼1 at. % Ag was present in both the matrix and GB precipitates in the Ag-modified alloy after T76 aging. Furthermore, the frequently reported decrease in the PFZ width with Ag addition was not observed after T76 aging, with both alloys having a similar PFZ width. Despite higher hardness/strength in the T4 condition with Ag addition, no enhanced age hardening response and alteration of the precipitation kinetics was observed during artificial aging at 121 °C. In fact, Ag addition in a 7xxx alloy with Zn/Mg ratio of 4 was found to be detrimental to mechanical properties, stress corrosion cracking, pitting and IGC resistance after T76 aging, which is attributed to the presence of the Ag-rich AlAgZnMgCu phase.

Efficient generation of singlet oxygen for photocatalytic degradation of antibiotics: Synergistic effects of Fe spin state reduction and energy transfer

Singlet oxygen (1O2) exhibits excellent degradation performance and stability in removing antibiotics from an aqueous environment. However, its production is limited by free radical competition. This study proposed a photocatalytic method employing ferrihydrite (Fh) as the base, coated with K-doped g-C3N4 and modified by AgCl (Ag/AgCl), leading to the KC3N4/AgCl/Fh composite for efficient 1O2 production. Compared with Fh, the loading of KC3N4 reduced Fe (III) spin, facilitating the rapid conversion of H2O2 to 1O2. The addition of Ag promoted the intersystem crossing process, decreasing the singlet-triplet energy gap from 0.0708 to 0.0458 eV, thereby effectively generating more triplet excitons to convert O2 into 1O2 in a targeted manner. The KC3N4/AgCl/Fh achieved a degradation rate of 98.10 % for enrofloxacin in 30 min, showing high effectiveness and stability. This work suggests a new way to create Fh-based photocatalysts for the efficient production of 1O2.

High-efficient hybrid arc and friction stir additive manufacturing of high-performance Al-Cu-Mg-Ag-Zr alloy: Microstructural evolution and precipitation behaviors with Ω/L12 co-precipitates

Cost-effective and convenient additive manufacturing technologies are recognized as suitable alternatives for achieving lightweight aluminum alloy components with dense and defect-free parts toward high mechanical properties. Herein, a high-efficient hybrid arc and friction stir additive manufacturing (HAFS-AM) technique was employed to fabricate a high-performance Al-Cu-Mg-Ag-Zr alloy part. The AC pulsed tungsten inert gas (TIG) was utilized for the rapid pre-deposition of Al-Cu-Mg-Ag-Zr alloy with high efficiency. Friction stir processing contributed to eliminating pore defects and refining coarse microstructure in the pre-deposited arc layers, accounting for enhancing mechanical properties. During the HAFS-AM, the coarse θ phase with continuous network morphology was completely broken and gradually dissolved into the α-Al matrix. The addition of Zr element promoted the precipitation of coherent L12-Al3Zr inducing dislocation shearing behavior. The Mg and Ag additions accelerated the precipitation of semi-coherent plate-like Ω and σ phases, where a critical size (thickness and diameter) of precipitates existed for deciding the behaviors of dislocation shearing and dislocation looping. The ultimate tensile strength and elongation of the HAFS-AMed steady-state layer reached 262 MPa and 18.8 %, which were increased by 21 % and 96 % compared to that of the arc layer, respectively. The combined effect of arc and friction stir with high efficiency achieved high-performance manufactured components, expediting the future industry application of advanced additive manufacturing technology.

Superior corrosion-resistant Zr-Ti-Ag thin film metallic glasses as potential biomaterials

Low-cost and non-cytotoxic ternary Zr-Ti-Ag thin film metallic glasses (TFMGs) were synthesized by DC magnetron sputtering. Results revealed that Ag addition enhanced the crystallization resistance and thermal stability of TFMGs. An appropriate Ag addition favored the mechanical property and corrosion resistance of TFMGs, while the excessive Ag addition had the opposite effect. Moreover, Ag did not directly form the passive film but altered the passive film stability and anti-corrosion capacity of TFMGs by inducing the disordered atomic arrangement, forming a dense microstructure, and tuning the corrosion-resistant Zr and Ti components. With low Young’s modulus of 116.2 GPa and passive current density of 0.45 × 10−7 A/cm2, the TFMG with an Ag target sputtering power of 11 W exhibited superior corrosion resistance, suggesting its application potential as biomaterials.

DFT-based adsorption studies of CNCl, HCN, and NH3 on metal-doped diamane

Density functional theory was used to comprehensively investigate the adsorption of cyanogen chloride (CNCl), hydrogen cyanide (HCN), and ammonia (NH3) by metal-doped diamanes. Because the weak gas adsorption ability of pure diamane renders it unsuitable for use as a gas sensor, the adsorption performance thereof was enhanced by doping with alkaline earth and transition metals. The adsorption capacities of monometallic-doped diamanes improved significantly for CNCl, HCN, and NH3. Notably, Be-doped diamane (BeD) delivered the highest adsorption performance for CNCl and HCN, whereas the addition of Au, Ag, and Cu, respectively, to diamane as dopants (AuD, AgD, and CuD) demonstrated enhanced adsorption effects for NH3. The adsorption capacities of the bimetallic co-doped diamanes for CNCl, HCN, and NH3 were significantly enhanced. In particular, diamane co-doped with Cu and Ag (Cu-AgD) exhibited superior adsorption for HCN and NH3, whereas Au and Cu co-doped diamane (Au-CuD) and Au and Ag co-doped diamane (Au-AgD) demonstrated improved adsorption effectiveness for NH3. The charge transfer, band gap, density of states, and charge density differences of these adsorption systems were investigated. Finally, recovery time analysis identified AuD, AgD, CuD, Au-CuD, Au-AgD, and Cu-AgD as potential candidates for reusable sensors.

Glass and nanocrystalline phase formation in CuZrAg alloys: Insights from combinatorial thin film libraries studied by mapping synchrotron X-ray diffraction

We report detailed diffraction peak analysis and parameters indicative of the transition between fully amorphous microstructures and nanocrystal formation in sputter deposited thin film metallic glasses. Specifically, we fabricated ternary CuZrAg alloy films (2µm thickness) with a large compositional gradient on flexible, X-ray transparent polymer substrates in high vacuum conditions. The combinatorial libraries were subjected to point-by-point structural (XRD synchrotron radiation) and chemical (X-ray fluorescence spectroscopy) analysis, characterizing roughly 172 alloys. A strong correlation was found between peak symmetry and width, and early stages of crystalline phase formation. These nanocrystals are difficult to detect from the evolution of the peak position. In view of current literature, our data questions the recently claimed universality of the peak width as indicator of high glass forming ability. The addition of Ag significantly improves the poor glass formation of binary CuZr (36 alloys) under identical deposition conditions, as fully amorphous alloys are found for the majority of the investigated composition space. A thorough understanding of the microstructure of CuZrAg alloys on flexible substrates is highly relevant in view of favourable antibacterial properties and potential application as coatings for biomedical surfaces.

Visible-light responsive Ag-doped ZnO/InVO4 composite photocatalyst for efficient degradation of tetracycline and Inactivate E. coli

Ternary heterostructured xAg/ZnO/InVO4 (x=2 %,5 %,7 %) composites were synthesized by a simple hydrothermal method. The prepared photocatalyst underwent characterization using a series of techniques, including XRD, BET, SEM, TEM, FTIR, and Raman spectroscopy. The photoluminescence spectra and electrochemical studies indicated that the addition of Ag promotes the effective separation of photogenerated charge carriers. The 5 % Ag/ZnO/InVO4 photocatalysts under visible light irradiation improved tetracycline removal to 88.6 % within 120 min. The highest degradation performance was achieved under the photocatalyst addition of 30 mg and pH 7. Moreover, the 5 % Ag/ZnO/InVO4 exhibited bactericidal activity against E. coli up to 100 %, which was significantly higher than that of the sum of ZnO, InVO4, and ZnO/InVO4. The radical scavengers trapping experiments revealed that ·OH, h+, and e- were generated in the photocatalytic process, and h+ played a major role in tetracycline degradation with a contribution of 72.3 %. According to the results of photochemical characterization and capture experiments, a detailed photocatalytic mechanism was proposed that the heterostructured combination of Ag, ZnO, and InVO4 provided synergistic photocatalytic activity through an efficient electron transfer process. An innovative concept for the process of environmental remediation is presented for the natural solar energy treatment of organic pollutants in bodies of water.

Microstructure characterization and age hardening response of Mg-8Sn-2Al alloy with Bi, Ag addition

The effects of Bi and Ag addition on the microstructure and age hardening response of Mg-8Sn-2Al alloy were investigated in this study. The Mg2Sn phase distributed along grain boundaries was observed in as-cast Mg-8Sn-2Al alloys and disappeared after solution treatment due to the Sn dissolution into ɑ-Mg matrix. However, a majority of Mg2Sn phase disappeared and few Mg2Sn particles still existed in the solid solutioned Mg-8Sn-2Al alloys containing Bi element. Mg2Sn precipitates formed in all peak-aged alloys. And Al, Bi and Ag elements are enriched in the areas of lath-shaped and spherical Mg2Sn precipitates in peak-aged Mg-8Sn-2Al-1.5Bi-1Ag alloy. Bi and Ag elements can act as heterogeneous nucleation sites and restrict the growth of precipitates to improve the age hardening response of Mg-8Sn-2Al alloy. Meanwhile, the undissolved Mg3Bi2 phase or early precipitated Mg3Bi2 phase during ageing treatment probably change the morphology and elements distribution of Mg2Sn precipitates. In addition, Ag and Bi atoms play a role on grain refinement and solution strengthening in Mg-8Sn-2Al alloy. Therefore, the micro-hardness value of peak-aged Mg-8Sn-2Al-1.5Bi-1Ag alloy increased to 69.9 HV from 47.4 HV of solid solutioned Mg-8Sn-2Al alloy. The precipitation behaviour, refined second phase, grain refinement and solute atoms synergistically made contributions to the strength improvement. The roles of Bi and Ag elements on improving age hardening response and precipitates characteristics are discussed in this study, which provides an important reference for exploring aged Mg-Sn alloys.

Correlation between microhardness and microstructure of low-temperature Sn-xBi-M(Ag, Sb) solders

The correlation between Vickers microhardness and microstructure of low-temperature Sn-xBi-M(Ag, Sb) solders was investigated. The β-Sn grains were refined with increasing Bi content, as well as the additions of Ag and Sb. Fine β-Sn grains in general should strengthen the mechanical properties of solders, however, the Vickers microhardness of Sn-xBi-M(Ag, Sb) solders decreased with increasing Bi content (i.e., fine β-Sn grains). It was shown that the microhardness of Sn-xBi-M(Ag, Sb) solders depended on the amount of Bi/β-Sn interfaces rather than the fine-grain strengthening effect. The smaller the amount of Bi/β-Sn interfaces was, the higher the Vickers microhardness of Sn-xBi-M(Ag, Sb) solders.

Influence of minor Mg/Ca/Nb/Ag addition on the morphology and microstructure of Fe-rich phase in powder metallurgy Cu[sbnd]10Fe alloy

The effect of Mg/Ca/Nb/Ag alloying on the morphology and microstructure of powder metallurgy Cu10Fe alloy was investigated systemically in this work. Alloying of Ca reduces the size of Fe-rich particles, while alloying of Mg/Nb/Ag increases the Fe-rich particles. This is attributed to the different roles of various alloying elements on the liquid-phase separation behaviors as well as diffusion of Fe atoms during the solidification. Coarse size spherical Fe-rich particles with a face centered cubic structure are observed in CuFe alloys bearing Mg/Ag/Nb, whilst the alloying of Ca favors the formation of fine spherical Fe-rich particles with a body centered cubic structure. The factor governing the morphology is found to be interfacial energy for CuFe alloys containing Mg/Ag/Nb and elastic energy for Cu-Fe-Ca alloy, respectively. Coarse size Fe-rich particles are hard to deform during subsequent rolling, but the fine Fe-rich particles can co-deform with Cu matrix. This study could provide a detailed picture regarding the influence of various alloying element types on the size, morphology, and lattice structure of Fe phase of CuFe alloy.

Effect of Ag Doping on Mechanical Properties of Cu6Sn5 Intermetallic Compounds

Cu6Sn5-xAg alloys (x = 0, 3, 6; %, mass fraction) were synthesized using Ag as a dopant through a high-temperature melting technique. The microstructure of the alloy was analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and other equipment, while the hardness of the alloy was measured to investigate the impact of Ag addition on the structure and microstructure of the Cu6Sn5 intermetallic compound. This study explored the influence of varying Ag contents on the properties of Cu6Sn5 intermetallic compounds, with calculations based on first principles revealing the mechanical properties and density of states of η′-Cu6Sn5 and its Ag-doped systems. The results indicated that Cu6Sn5-xAg alloys predominantly existed in three distinct forms, all exhibiting large masses without any impurities or precipitates. First-principle calculations demonstrated that Ag substitution in certain sites suppressed the anisotropy of the Young’s modulus of Cu6Sn5, particularly in the Cu1, Cu3, Sn1, and Sn3 positions, while the effect was less significant at the Cu2, Cu4, and Sn2 sites. The introduction of Ag through doping enhanced the covalent bonding within the η′-Cu6Sn5 structure, promoting the formation of a stable (Cu, Ag)6Sn5 structure.

Microstructure and mechanical behavior of Sn15Bi-xAg\Cu solder joints during isothermal aging

Purpose This paper aims to focus on the reliability of Sn15Bi–xAg and Sn15Bi–xCu solder joints during isothermal aging. Design/methodology/approach The effects of Ag or Cu additions on the microstructure, interfacial metallic compound layer and shear strength of Sn–15Bi (Sn15Bi) based solder joints during were investigated. The effects of Ag or Cu additions on the microstructure and tensile properties of Sn15Bi-based bulk solders were also investigated to provide a comprehensive analysis. The interfacial morphology and microstructure were observed by scanning electron microscopy and the composition in the structure was examined by energy dispersive spectrometer. The shear tests were carried out on the as-soldered and as-aged joints using a ball shear tester. Findings The results revealed that by adding Ag or Cu, the microstructure of Sn15Bi solder can be refined. Ag addition increased the tensile strength of Sn15Bi solder but had little effect on elongation. However, Cu addition decreased the tensile strength and elongation of Sn15Bi solder. For solder joints, Ag addition increased the shear strength and toughness of Sn15Bi/Cu joints but Cu addition decreased the shear strength and toughness of Sn15Bi/Cu joints. Originality/value The authors can potentially provide a replacement for Sn40Pb traditional solder with Sn15Bi solder by alloying Ag or Cu due to its lower cost and similar melting point as Sn–Pb solder.

Effects of Ag/Sc microadditions on the precipitation of over-aged Al–Zn–Mg–Cu alloys

Microalloying addition plays a significant role in controlling the characteristics of precipitates in Al alloys. This study investigates the effects of Ag and Sc microalloying addition on the thermal stability of Al–Zn–Mg–Cu alloys, via differential scanning calorimetry, transmission electron microscopy, and atom-probe tomography. The results demonstrate that Ag and Sc additions increase the number density of η-MgZn2 type nano-precipitates (formed during heat treatment) by forming direct (Mg–Ag phase, prototype of precipitate) or indirect precursors (Al2Sc phase, constituent of precipitate) for the precipitate. In addition, the Ag and Sc elements can effectively prevent the coarsening of η precipitates and facilitate the high-density distribution of fine η precipitates, during the over-aging period, improving the thermal stability of the Al–Zn–Mg–Cu alloys. The thermal stability is particularly improved by Ag addition because Ag atoms directly prevent the coarsening of η precipitates by hindering Zn diffusion into the precipitate. On the contrary, Sc addition indirectly prevents the coarsening of η precipitates by depleting the solute species from the Al matrix, enabling abundant precipitates limited growth. Thus Ag addition improves precipitation strengthening by preventing the coarsening of precipitates during over-aging.

Measurement of Diffusion Coefficients and Assessment of Atomic Mobilities in HCP Mg-Ag-Sn Alloys

Reliable thermodynamic and kinetic databases are essential for designing and developing novel magnesium (Mg) alloys for elevated-temperature applications in the automotive and aerospace industries. This study investigated diffusion behaviors of HCP Mg-Ag-Sn alloys by four sets of three diffusion couples annealed at 450, 500, and 550 °C, respectively. Interdiffusion and impurity diffusion coefficients at the three annealing temperatures were extracted using the forward-simulation method. The determined diffusion coefficients, combined with prior results in the literature, were then used to assess atomic mobilities for the HCP phase of the Mg-Ag-Sn system. This assessment was conducted using the DICTRA and the TCMG5 thermodynamic database within the Thermo-Calc software. Comprehensive comparisons between calculated and experimental diffusion coefficients yielded an excellent agreement. The atomic mobilities were also further validated by appropriate predictions of concentration profiles and diffusion paths observed in independent diffusion couple experiments performed at 525 °C for 18 hrs. It has been found that the addition of Sn and Ag both increase the diffusivity of Ag in HCP Mg and Sn in HCP Mg in the stable temperature range of HCP Mg, respectively. This improved understanding of the kinetics in the Mg-Ag-Sn ternary system is essential for controlling diffusion-dependent properties such as coarsening and, therefore, the mechanical properties of Mg-Ag-Sn alloys at elevated temperatures.

High-temperature tribological behaviour and machining performance of self-lubricant CrAlNAg coatings for dry milling operations

Tribological and machining performance of CrAlNAg coatings having different Ag content tested against AISI 1045 medium carbon steel were assessed. Wear track was evaluated by scanning electron microscopy and energy dispersive spectroscopy. 3D topography of wear track and ball counterpart was determined by non-contact type profilometer. The formation of different oxide phases on track was confirmed using Raman spectroscopy. CrAlNAg9 and CrAlNAg12 coatings were found beneficial in reducing material adhesion from counterpart thus providing protective layers to counterpart, whereas small addition of Ag did not provide any improvement on CrAlN coating performance. CrAlNAg9 coated milling inserts demonstrated best results in terms of reduction in chip temperature (∼17.5 %), cutting forces, surface roughness (∼47 %) and chip thickness (∼12.7 %) compared to uncoated inserts.