Surface Microstructure Research Articles

Optimizing sheet metal edge quality with laser-polishing: surface characterization and performance evaluation

Dual-phase (DP) steels are widely used in the automotive industry due to their exceptional performance. It offers excellent strength, ductility, formability, and weldability. However, there is a high risk of edge cracking, particularly in materials like DP1000 steel, caused by residual damage from blanking, such as microcracks and burrs, which needs further investigation. In this study, the transformative potential of laser-polishing on DP1000 steel was investigated. The goal was to reduce edge crack sensitivity and enhance edge formability. In this work, laser-polished samples produced by various pre-manufacturing techniques such as sawing, punching, and waterjet cutting were examined. Various evaluations were performed on laser-polished samples. Those included white-light-confocal microscopy, scanning electron microscopy, and Electron Backscatter Diffraction (EBSD) analysis. Those evaluations aimed to analyze the microstructural transformation, surface roughness, and micro grain size distribution resulting from laser-polishing. Laser-polishing is a process in which the edge of the sample is remelted locally. Hence, residual damage vanishes, and surface defects disappear, which should be beneficial for edge formability. On the other hand, the cooling rate during re-solidification is high, leading to high strength and reduced ductility compared to the initial DP steel. Therefore, hole expansion tests were conducted to evaluate the edge formability of the steel. The results indicated a significant improvement in the hole expansion ratio of the laser-polished samples compared to samples with conventional manufactured edges. These findings will help to assess the advantages and limitations of laser-polishing in sheet material manufacturing.

Strain Effects in the Work Function and Charge Transfer of the Au(111) Surface.

Work function (WF) is one of the most fundamental physical parameters of metal surfaces, which can not only reflect the electronic structure of metal surfaces but is also very sensitive to the surface microstructure. In this paper, we use first-principles calculations to systematically study the strain effects on the vacuum level, Fermi level, and WF of the Au(111) surface. We find that the vacuum level and Fermi level of the Au(111) surface increase under compressive strain and decrease under tensile strain, and the effects of biaxial strain on the vacuum level and Fermi level can be equivalent to the superposition of two perpendicular uniaxial strains. These strain effects are attributed to the charge transfer induced by the strain. However, the change of WF with strain is the result of the competition between the strain effects of the vacuum level and Fermi level. That leads to the WF increasing with compressive uniaxial strain and decreasing with tensile uniaxial strain. Moreover, because the Fermi level is more responsive to compressive uniaxial strain, the Fermi level changes faster than the vacuum level under compressive biaxial strain. Consequently, the WF decreases with increasing tensile biaxial strain and slightly increases before decreasing with increasing compressive biaxial strain.

Effects of retained austenite and martensite microstructure on fatigue crack propagation in quenched and tempered high carbon steels

Commercial high-carbon 52,100 steel was subjected to varying quenching and tempering heat treatments to develop plate martensite and retained austenite (RA). The mode I fatigue crack growth (FCG) behavior of quenched and tempered microstructures with varying amount of RA and degree of martensite tempering was investigated. The interaction between the fatigue cracks and the surrounding microstructure was characterized using electron microscopy/backscatter diffraction and quantitative fractography. Higher initial amounts of RA and greater degree of martensite tempering improved FCG resistance of high-carbon plate-martensite austenite microstructures. Stress-assisted RA to martensite transformation was observed in the vicinity of the fatigue cracks in the microstructure heat treated to have an elevated amount of RA. The fatigue fracture surfaces of the different microstructures exhibited varying combinations of intergranular (IG) fracture, mixed-ductile brittle (MDB) and transgranular (TG: cleavage, quasi-cleavage, and ductile striations) fracture as a function of stress intensity range at the crack tip. Microstructure conditions showing greater fractions of MDB and TG fatigue fracture had better FCG resistance. The presence of a higher initial RA content suppressed brittle IG fracture and promoted TG fracture, potentially due to transformation–toughening associated with RA to martensite transformation or transformation induced micro-crack coalescence near the fatigue crack.

Mg2+ ion conducting Chitosan:PVP polymer blend electrolytes for electric double layer capacitor applications

Biopolymer electrolytes are prepared using Chitosan (CS) and Polyvinyl pyrrolidone (PVP) incorporated with magnesium chloride (MgCl2). The complex formation of electrolytes are confirmed by X-ray diffraction(XRD) and Fourier Transform Infrared spectrometer(FTIR) analysis. The scanning electron microscope(SEM) reveals the surface morphology and microstructure of the electrolytes while energy dispersive spectroscopy(EDS) facilitates the presence of elements. The distribution of elements are confirmed with elemental mapping analysis. DSC analysis enlightens on thermal properties, offering an understanding of phase transitions and thermal stability of the films. CS/PVP/MgCl2(50:50:25) polymer electrolyte shows higher ionic conductivity value of 5.8 × 10−4 S/cm at 30 °C and the specific capacitance value of 86.5 Fg−1 at low scan rate of 10 mVs−1. Linear Sweep Voltammetry (LSV) analysis has been used to determine the electrochemical stability window of the electrolyte and it is found to be 0.7 V. This result indicates that the CS/PVP/MgCl2 electrolyte is a suitable material for energy storage device applications.

Bio-inspired multimimimetic synergistic strategies Cs3Bi2Br9/ZnS organosilicon antifouling flexible films: Coupled micro/nanostructured surfaces, fluorescence, and reactive oxygen species mechanisms

Constructing multifaceted bio-inspired environmentally friendly films combining the synergistic advantages of multiple bionics can improve the static antifouling effect of antifouling-releasing silicones and mitigate the toxicity to marine ecology. In this work, based on the multiple anti-fouling mechanisms of fluorescent corals, designed Cs3Bi2Br9/ZnS/PDMS (CZP) flexible fluorescent films with surface microstructures and interpenetrating network Moreover, the blue fluorescence in the CZP films can be maintained for a long time in seawater environment (attributed to bismuth-based chalcogenides), and the formation of the heterostructure of Cs3Bi2Br9/ZnS (CBB/ZS) improves the ability of releasing reactive oxygen species (hydroxyl radical, superoxide radical, and singlet-linear oxygen).The CZP films obtained excellent antifouling effect under static conditions with antimicrobial rate up to 90.51 % and anti-algae adhesion to diatoms up to 96.60 %, which was attributed to the synergistic effect of the fluorescence functionality, micronized structure, and free radical release. Consequently, this work provides a promising avenue for the development of marine antifouling silicon-based films for efficient and environmentally friendly applications.

Fiber laser irradiation in chemical solution for micro fabrication: Mechanisms and applications

The laser and electrochemical hybrid machining (LECM) could realize high-efficient and quality processing of difficult-to-cut materials and has become a research topic in microfabrication. However, it was difficult to ensure the stability and efficiency of laser transmission in chemical solutions, and an external voltage and auxiliary cathode should be added. In the present study, a novel fiber laser irradiation in chemical solution (LICS) has been proposed to process microstructures. The surface microstructures and chemical composition of the surfaces processed by LICS, laser irradiation in the ultrapure water, and electrochemical machining were compared. In LICS the materials were removed by laser processing and the following high-temperature gradient induced electrochemical dissolution. The high temperature gradient induced electrochemical dissolution could enhance the MRR and improve the surface quality. LICS can be regarded as a novel LECM process. The machining efficiency of LICS had been improved by 46.2 % compared with that laser irradiation in the ultrapure water, and the proportion of laser-induced electrochemical dissolution was 31.6 % in the LICS process. Further, the effects of laser power, chemical solution concentration, and optical fiber end movement control on the processing of micro grooves were explored, considering the dimension, MRR, and surface roughness. A front gap of smaller than 0.8 mm between the optical fiber end and workpiece was recommended during LICS. The repeated feeding of optical fiber was proposed to improve the depth-to-width ratio of the micro grooves fabricated by LICS. Finally, LICS was used to process microstructures with the controlled profiles on the nickel-based superalloy and titanium alloy workpieces without a recast layer, which holds great potential in surface microfabrication and texturing.

Surface integrity improvement of the ground surface of Inconel 718 fabricated by forging and additive manufacturing using a robotic rotational burnishing method

Given that the surface acts as the primary interface with the surrounding environment, the surface integrity of a component significantly influences its operational effectiveness. In the aerospace industry, materials like Inconel 718 are often utilized for their high-temperature strength despite their poor thermal conductivity and machinability, resulting in inferior surface integrity during grinding procedures. This research proposes an innovative robotic rotational burnishing method that leverages self-generated heat to aid in the post-grinding burnishing process, eliminating the need for an external heat source. The surface integrity achieved through this method undergoes a comprehensive evaluation, encompassing surface topological features, microstructure, and mechanical properties, and is compared with surfaces treated by grinding and slide burnishing. The findings demonstrate that during the rotational burnishing process, the friction between the high-speed rotating burnishing tip and the workpiece surface induces circumferential flow of the surface material, thereby enhancing surface anisotropy. Additionally, this process generates significant heat, further encouraging plastic deformation of the material surface under high burnishing forces. As a result, the surface acquires a compressive residual stress exceeding 1000 MPa and develops a microhardness-strengthened layer with a thickness exceeding 500 μm. Both forging and additive manufacturing techniques for preparing Inconel 718 raw materials yield consistent outcomes. This study not only achieves a fusion of additive, subtractive, and equivalent manufacturing but also validates the applicability of the proposed robotic rotational burnishing method in enhancing surface integrity across materials manufactured by various techniques.

Flexible and sensitive three-dimension structured indium tin oxide/zinc aluminum oxide/Cu composites thin-films pressure sensors for healthcare monitoring

Flexible pressure sensors play a crucial role in large-scale commercial applications, such as health monitoring, robotics, and smart devices. However, mass production of piezoelectric sensors for industrial applications is limited by their complex and cost-intensive fabrication processes. In this study, sensitive, simple, and wearable piezoelectric sensors were prepared by magnetron sputtering of indium tin oxide/zinc aluminum oxide (AZO)/Cu composite thin films onto three-dimension structured polydimethylsiloxane) substrate. The prepared flexible sensors delivered output voltages of −200 mV and +200 mV during 1000 loading and unloading cycles, respectively, showing an outstanding sensitivity and cycling performance. The piezoelectric performance of AZO films is primarily determined by the doping concentration of aluminum in AZO; the output voltage of the sensor with the optimal doping concentration was approximately 340 % higher than that of the undoped sample. Finite-element simulations demonstrated that the substrate with a square platform exhibited the most uniform stress distributions as well as the highest stress on its microstructure surface, which resulted in a high stress and sensitivity of the thin-film sensors. Experiments revealed that the incorporation of a microstructure enhanced the output voltages of the sensors. In particular, the output voltage delivered by the flexible sensors with square microstructures was approximately 60 % higher than that exhibited by those without microstructures.

Surface quality and microstructure evolution in fused silica under SF6/Ar reactive ion beam etching

The SF6/Ar reactive ion beam etching (RIBE) was proposed to explore the evolution of surface quality, subsurface defects, surface molecular structure, and chemical composition of fused silica. Also, the mechanism of reactive ion beam etching of fused silica surfaces was discussed. The results show that RIBE can maintain the original surface roughness by choosing suitable process parameters. this etching process can suppress the replication and expansion of subsurface defects and the deposition of reactants without bringing obvious contamination. The concentration of structural defects reaches a minimum at an etching depth of about 2 μm. However, further etching may lead to an increase in the chemical structure defects on the surface. The evolution of the intrinsic ring structure demonstrates that most intrinsic defects tend to reorganize into short (Si-O) ring structures. The etching mechanisms of Ar ions were discussed by simulating the stopping power and energy deposition. Phonon dissipation through atomic displacements and atomic vibrations is an important way of energy loss. Phonon vibrations and atomic dislocations induced by nuclear collisions are not only important factors causing the enhancement of electron-phonon coupling but also important causes of surface structural defects. The researches provide a theoretical basis for in-depth understanding of fused silica surface defect repair.

Effect of aging temperature on the lubricated wear resistance of multi-directionally forged Al-40Zn-3Cu alloy

The effect of aging temperature on the lubricated wear behavior of multi directionally forged Al-40Zn-3Cu alloy was systematically investigated at different loads and sliding speeds. Microstructural and worn surface examinations of the alloy samples were performed by scanning electron microscopy, scanning transmission electron microscopy and energy dispersive spectrometry while their tribological properties were investigated with a ball on disc type wear test apparatus. The results showed that aging treatment at different temperatures after multi-directional forging changed the morphology of Zn-rich nanoscale η precipitates and Cu-rich θ particles and their dispersion in α-Al matrix. Their changes brought about an increase in hardness, strength, and wear resistance of Al-40Zn-3Cu alloy but a decrease in its ductility. It was also observed that the aging temperature, load and sliding speed had a combined effect on their wear response. As the applied load and sliding speed increased, friction coefficient of the samples decreased while their mass loss increased continuously with load but decreased with sliding speed after showing an increase. The adhesion, abrasion and oxidation were observed to be operative wear mechanisms for the alloy. The wear results of the alloy samples were discussed in terms of their microstructures and mechanical properties, and oil lubrication. The aging treatment at 150 °C after multi-directional forging increased the wear resistance of Al-40Zn-3Cu alloy more than 50 percent by providing a moderate hardness (129 HB), yield strength (310.9 MPa), tensile strength (383.2 MPa), and ductility (9.9 %).

Study of the rolling wetting behavior of droplets on surfaces with T-shaped microstructures

The regulation of droplet wetting behavior encompasses multiple professional disciplines, and the surface microstructure has become the preferred approach for controlling droplet wetting behavior. Bionic studies have revealed that springtails can effortlessly move in water because of the T-shaped microstructures on their skin, which prompted the design of various T-shaped microstructures to effectively regulate droplet wetting behavior. Although the static wetting theory for T-shaped microstructure surfaces is well understood, the dynamic wetting theory regarding droplet rolling remains unexplored. This study aims to investigate the rolling behavior of droplets on inclined surfaces with T-shaped microstructures through theoretical analysis and numerical simulation. By analyzing the comprehensive energy transformation and gas-liquid interface morphology during the tilting processes, we revealed the mechanism by which the geometric parameters of the T-shaped microstructures influence the droplet rolling behavior and constructed an energy prediction analysis model for the final droplet morphology. The results showed that reducing the cantilever height, increasing the structural spacing, and enlarging the droplet size facilitated continuous rolling of the droplets. Additionally, we discovered that the driving energy for droplet rolling on inclined surfaces with T-shaped microstructures originates from the surface free energy. The maximum surface free energy of a droplet often occurs when the droplet begins to roll.

A Comparative Analysis of Enamel Surface Roughness Following Various Interproximal Reduction Techniques: An Examination Using Scanning Electron Microscopy and Atomic Force Microscopy.

Interproximal enamel reduction (IER) is a minimally invasive therapeutic procedure commonly used in orthodontics to address both functional and aesthetic issues. Its mechanical effects on enamel surfaces induce the formation of grooves, furrows, scratches, depressions, and valleys. The aim of this study was to assess the enamel surface roughness resulting after the application of currently available methods for interproximal reduction. Ninety freshly extracted human teeth were divided into six groups and subjected to the stripping procedure, using a different method for each group (diamond burs, abrasive strips of 90 μm, 60 μm, 40 μm, 15 μm, and abrasive discs). A single individual performed stripping according to the manufacturer's recommendations, involving interproximal reduction on one tooth's proximal face and leaving the other side untreated. Qualitative and quantitative assessment of the enamel surfaces was carried out using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM), obtaining 2D and volumetric 3D images of the enamel surface microstructure and nanostructure. The study found that diamond burs and abrasive strips of 60 μm and 90 μm increased enamel roughness due to intense de-structuring effects, while the 40 μm polisher had a gentler effect and 15 μm abrasive strips and polishing discs preserved enamel surface quality and removed natural wear traces.

Experimental study of nucleate boiling heat transfer of refrigerant-oil mixture on various modified surfaces

As a crucial component of refrigeration and heat pump system, the evaporator performance directly affects system efficiency. Due to the lubricating oil in the compressor circulating into the evaporator, studying the nucleate boiling heat transfer (NBHT) of refrigerant-oil mixture is of greater practical and guiding significance. Surface modification technology has opened up a new avenue for enhancing NBHT of refrigerant-oil mixture. Therefore, experimental study was conducted on NBHT characteristics of R134a-POE mixture and R1234ze(E)-POE mixture on smooth surface, initial laser-ablated surface, stabilized laser-ablated surface, machined surface, and composite processed surface. The effects of oil concentration (ω), surface microstructure and surface wettability on NBHT of refrigerant were discussed and analyzed, and the underlying heat transfer mechanisms were elucidated. The research indicates that for NBHT of refrigerant-oil mixture, surface microstructure has a greater impact than surface wettability. To enhance heat transfer coefficient (HTC), it is crucial to establish a surface pattern comprising alternating regions of high and low nucleation sites to mitigate bubble interaction and coalescence. Once this objective is attained, enhancing surface wettability can be contemplated. The addition of oil promotes foaming and induces tornado-shaped bubble group, which facilitate heat transfer. However, the rise in mixture viscosity and surface tension exerts a more pronounced adverse effect on heat transfer, outweighing the positive impacts of foaming and tornado-shaped bubble group. Consequently, the presence of oil diminishes HTC. And as ω and heat flux increase, HTC further decreases. Additionally, the increase in vaporization nuclei on modified surface leads to a higher local ω, the increase in ω further weakens the enhanced heat transfer effect of modified surface, and thus narrows the difference in HTC among various modified surfaces. The research results aim to uncover the mechanisms by which surface wettability, surface microstructure, and lubricating oil affect NBHT of refrigerant.

Study on Electrical and Mechanical Properties of Double-End Supported Elastic Substrate Prepared by Wet Etching Process.

Preparing elastic substrates as a carrier for dual-end supported nickel chromium thin film strain sensors is crucial. Wet etching is a vital microfabrication process widely used in producing microelectronic components for various applications. This article combines lithography and wet etching methods to microprocess the external dimensions and rectangular grooves of 304 stainless steel substrates. The single-factor variable method was used to explore the influence mechanism of FeCl3, HCl, HNO3, and temperature on the etching rate, etching factor, and etching surface roughness. The optimal etching parameter combination was summarized: an FeCl3 concentration of 350 g/L, HCl concentration of 150 mL/L, HNO3 concentration of 100 mL/L, and temperature of 40 °C. In addition, by comparing the surface morphology, microstructure, and chemical and mechanical properties of a 304 stainless steel substrate before and after etching treatment, it can be seen that the height difference of the substrate surface before and after etching is between 160 μm and -70 μm, which is basically consistent with the initial design of 0.2 mm. The results of an XPS analysis and Raman spectroscopy analysis both indicate that the surface C content increases after etching, and the corrosion resistance of the surface after etching decreases. The nano-hardness after etching increased by 26.4% compared to before, and the ζ value decreased by 7%. The combined XPS and Raman results indicate that the changes in surface mechanical properties of 304 stainless steel substrates after etching are mainly caused by the formation of micro-nanostructures, grain boundary density, and dislocations after wet etching. Compared with the initial rectangular substrate, the strain of the I-shaped substrate after wet etching increased by 3.5-4 times. The results of this study provide the preliminary process parameters for the wet etching of a 304 stainless steel substrate of a strain measuring force sensor and have certain guiding significance for the realization of simple steps and low cost of 304 stainless steel substrate micro-nano-processing.

ZrO2-CeO2/WO3 heterostructure films prepared by magnetron sputtering for humidity-tolerant triethylamine sensing

Up to now, the development of gas sensors based on metal oxide semiconductors (MOSs) that can detect triethylamine (TEA) under high humidity conditions remains a significant challenge. In this study, we present the ZrO2-CeO2/WO3 (ZCW) heterostructure films for TEA detection under high relative humidity, which were prepared by co-sputtering ZrO2 and CeO2 onto the surface of a WO3 film using the radio frequency magnetron sputtering method. The gas sensors based on the ZCW heterostructure films exhibited outstanding TEA-sensing performance, including high response (18.56–20 ppm), rapid response/recovery rate (1/5 s), excellent selectivity, wide detection range (0.5–500 ppm), outstanding reproducibility and stability, and ideal anti-humidity ability. The excellent TEA-sensing properties of the ZCW heterostructure films should be mainly attributed to their unique surface microstructure, abundant oxygen vacancies, and the formation of heterostructures between ZrO2, CeO2, and WO3. Compared to the WO3 film, both the CeO2/WO3 and ZrO2-CeO2/WO3 films demonstrated highly-enhanced humidity-tolerant performance, which should result from the redox reactions between the Ce3+ and Ce4+ ions. This study provides a general method for preparing the MOSs-based TEA sensors that could work under high humidity condition.

Improving mechanical properties and corrosion behavior of biomedical Ti-3Zr-2Sn-3Mo-25Nb alloy through laser surface remelting

Laser surface remelting offers a promising approach to enhance both the mechanical properties and corrosion resistance of metallic materials by tailoring their surface microstructures. This investigation specifically observed a phase transformation in the Ti-3Zr-2Sn-3Mo-25Nb (TLM) alloy from β to lamellar martensite α“ during the process, resulting in a refined grain structure. Geometrical phase analysis (GPA) revealed heightened internal compressive stress and the accumulation of dislocations along the β/α” interface, contributing to increased strength following laser treatment. Notably, the treated TLM alloy exhibited improved ductility, attributed to the presence of {332} 〈113〉 twinning during dynamic recrystallization. Moreover, the laser-treated surface significantly enhanced corrosion resistance compared to the untreated alloy. This study is anticipated to present an effective approach to prolonging the lifespan of TLM alloy by manipulating its surface microstructure through laser surface remelting.

Role of slip in hydrogen-assisted crack initiation in Ni-based alloy 725.

We conduct in situ tensile straining experiments to investigate the role of hydrogen and slip in crack initiation in nickel-based alloy 725. Our experiments reveal no tendency for hydrogen to enhance localized slip and no necessity of slip for crack initiation. We use electrochemical charging to introduce hydrogen into samples, melt extraction to measure hydrogen content, and digital image correlation to analyze localized plastic strains during in situ tensile tests in a scanning electron microscope. Cracks initiate both in regions with and without nearby localized slip. Moreover, the fraction of cracks initiating with no nearby slip is greater at higher hydrogen content. Slip-assisted crack initiation generally occurs at locations where intergranular slip is arrested, especially at intersections of slipping coherent twin boundaries with thin twin lamellae. Cracks that initiate without nearby slip occur at a wider variety of microstructural features, including inclusions, triple junctions, and surface flaws.

Development of Lead‐Free Defect Brownmillerite Perovskite Ceramic LiBiFeMnO5 Solid Solution for Electronic Devices

This article reports the fabrication (synthesis) and characterizations (structural, microstructural topographic surface, dielectric, transport, impedance, current–voltage, and resistive properties) of a complex lead‐free defect perovskite material of composition LiBiFeMnO5. A preliminary structural investigation of the X‐ray diffraction pattern using N‐TREOR09 methods shows monoclinic symmetry. The scanning electron microscopic spectrum examines the sample's microstructural topographic surface, fractal study, and roughness (using the standard ISO25178). The analysis of Maxwell–Wagner dielectric dispersion, relaxation, and transport mechanisms is investigated utilizing dielectric, impedance, and conductivity spectrum accumulated within the experimental frequency of (1 kHz–1 MHz) at different temperatures (30–500 °C). A nonoverlapping small polaron tunneling conduction mechanism and correlated barrier hopping mechanism in the material have helped to understand its conduction phenomena. The Ohmic and space–charge limited conduction mechanisms are investigated by the slope of the logarithmic electric field (E) and current density (J). The thermistor constant (β) is determined to be 1982.87. The temperature coefficient of resistance is found to be −0.00419, which may be suitable for negative temperature coefficient thermistors, sensors, and other related devices.

Manganese cobalt sulfide nanoparticles wrapped by reduced graphene oxide: a fascinating nanocomposite as an efficient electrochemical sensing platform for vanillin determination

In this work, a fascinating nanocomposite based on manganese-cobalt sulfide (MnS/Co3S4) wrapped by electrochemically reduced graphene oxide (ERGO) has been successfully synthesized on the surface of a glassy carbon electrode (GCE) by a facile hydrothermal assisted electrochemical reduction method. The modified electrode was fully characterized by scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The morphological results illustrate that MnS/Co3S4 are embedded in the ERGO layers, resulting in a rough surface and three-dimensional (3D) microstructure. The as-synthesized MnS/Co3S4-ERGO/GCE displays distinctly enhanced electrocatalytic activity for vanillin oxidation in comparison with that of the ERGO/GCE and MnS/Co3S4/GCE. Therefore, the MnS/Co3S4-ERGO/GCE can be used as an effective electrochemical sensing platform for the sensitive determination of vanillin, and the fabricated sensor displays a wide linear range of 0.02−1.00 μmol/L and 1.0−40.0 μmol/L, low detection limit of 4.0 nmol/L and satisfactory recoveries between 98.0% and 102.8%.

Exploring innovative antibacterial properties of porous ALT (Al2O3/TiO2) composite

Among all metallic materials, titanium is mostly employed in medical applications. In this study, single TiO2 layers on Ti as well as composite ALT(Al2O3/TiO2) layers on Ti for medical applications were synthesized using titanium and aluminum cathodic cages. SEM, EDX, XRD, PL, UV–Vis analyses of untreated and plasma-processed samples were used to determine the surface morphology, chemical content, microstructure, band gap, and photocatalytic behavior, respectively. E. coli and S. aureus immersion bacterial solutions were used to test the antibacterial performance of untreated and plasma-processed specimens. Comparing the composite to a single TiO2 and an untreated sample in PL spectra revealed a smaller band gap. When compared to untreated specimens, coatings made of TiO2 and composite ALT demonstrated significant antibacterial properties. The results showed that ALT-60min displayed unique antibacterial behavior because the band gap was reduced and antibacterial effectiveness was increased. This work explains the distinctive antibacterial activity of composite nanostructures made for medicinal use.