Surface Properties Of Materials Research Articles

Hollow Porous Cu2S Nano-Spheres as High-Rate Magnesium Battery Cathode

The magnesium ion batteries are gaining huge attention in the field of battery energy due to high energy density, low cost potential and high safety performance. So far, the research of magnesium ion batteries has been slow. The surface and structural properties of cathode electrode materials greatly limiting the discharge performance of magnesium ion battery. Herein, a facile synthesis of Cu2S nano-hollow spheres for high performance magnesium ion battery cathode electrode materials was reported. This nano-hollow spheres have a large specific surface area (12.84 m2 g−1) which can reduce the volume expansion caused by magnesium ions during embedding and detachment, and facilitate ion diffusion during the discharge-charging process. Consequently, the nano-hollow porous Cu2S deliver a 152 mAh g−1 after 850 cycles at 560 mA g−1 hold a long-term cycling stability as cathode materials for magnesium ion battery. This work not only demonstrates the great potential of NHP-Cu2S materials, for application in magnesium ion batteries, but also sheds a new light on the application of metal sulfides in magnesium ion batteries.

Tuning low frequency dielectric properties of flexible ternary polymer blend film reinforced with bio- ionic liquid for the application in green electronics

Biofriendly conducting polymeric blends and composites exhibiting high dielectric constant and dielectric loss are promising for applications as sensors, actuators, microwave absorbing materials, fuel cells and biomedical applications. A great deal of work is reported on using fillers such as conductive nanomaterials, bio ceramics, carbon nanotubes, graphene etc in blends of Polyvinylchloride, Polyvinylpyrrolidone, Polymethylmethacrylate, Polyvinyl alcohol with conducting polymer Polypyrrole, Polyaniline for enhancing their conductivities, tailoring dielectric and electrical, thermal and surface properties of such polymeric materials. However, appropriate dispersion of such fillers in polymeric matrices remains technically challenging. In this regard, bio-ionic liquids have emerged as a novel class of materials and their combination with specific polymer blends opens the possibility to develop smart novel materials with different morphologies. Present work aims to explore the low frequency dielectric properties exhibited by free standing, flexible, biofriendly/biodegradable ternary polymer blend film of Polyvinylchloride-Polyvinylpyrrolidone-Polypyrrole reinforced with choline acetate. The detailed analysis of low frequency dielectric properties authenticates that addition of choline acetate result in modifying the dielectric properties of ternary polymer blend film.. The harmlessness of these films was confirmed from disk diffusion test indicating their benign nature towards (Escherichia coli) (CFT073) and (Bacillus subtilis). Therefore, the developed films can potentially be used for various scale multifunctional dielectric and electrical applications working in close contact with living matter, green electronics and various health monitoring systems.

Post-Production Finishing Processes Utilized in 3D Printing Technologies

Additive manufacturing (AM) has revolutionized production across industries, yet challenges persist in achieving optimal part quality. This paper studies the enhancement of post-processing techniques to elevate the overall quality of AM-produced components. This study focuses on optimizing various post-processing methodologies to address prevalent issues such as surface roughness, dimensional accuracy, and material properties. Through an extensive review, this article identifies and evaluates a spectrum of post-processing methods, encompassing thermal, chemical, and mechanical treatments. Special attention is given to their effects on different types of additive manufacturing technologies, including selective laser sintering (SLS), fused deposition modeling (FDM), and stereolithography (SLA) and their dedicated raw materials. The findings highlight the significance of tailored post-processing approaches in mitigating inherent defects, optimizing surface finish, and enhancing mechanical properties. Additionally, this study proposes novel post-processing procedures to achieve superior quality while minimizing fabrication time and infrastructure and material costs. The integration of post-processing techniques such as cleaning, surface finishing, heat treatment, support structure removal, surface coating, electropolishing, ultrasonic finishing, and hot isostatic pressing (HIP), as steps directly within the additive manufacturing workflow can immensely contribute toward this direction. The outcomes displayed in this article not only make a valuable contribution to the progression of knowledge regarding post-processing methods but also offer practical implications for manufacturers and researchers who are interested in improving the quality standards of additive manufacturing processes.

Concentration and reaction duration effects on synthesizing ZIF67 derivatives with NH4BF4 and NH4HF2 as efficient active material of energy storage device

Zeolitic imidazolate framework-67 (ZIF67) with large surface area and tunable pore structure is intensively applied as a tailoring target for design active materials. An in-situ tailoring technique is proposed to design ZIF67 derivatives by using structure directing agents (SDA) to induce favorable morphology and composition. Ammonium fluoride is a common SDA for modifying surface properties of active materials. With the same ammonium and similar fluorine-based groups, NH4BF4 and NH4HF2 are priming to play as SDA for synthesizing ZIF67 derivatives. In this study, the synthetic process of ZIF67 derivatives is tailored by varying the precursor concentration and reaction time in systems with NH4BF4 and NH4HF2 as SDA. The precursor concentration plays significant roles in the composition of ZIF67 derivatives. The reaction duration has higher influences on the morphology. The highest specific capacitance (CF) of 1347.0 F/g at 20 mV/s is achieved for the ZIF67 derivative synthesized using low concentration and 18 h, owing to favorable cobalt and nickel hydroxide compositions and two-dimensional sheet-like structure. An energy storage device composed of the optimal ZIF67 derivative and carbon electrodes shows a maximum energy density of 11.96 Wh/kg at 650 W/kg. The excellent cycling stability with CF retention of 83.6% and Coulombic efficiency of 92.0% is obtained after 10000 cycles.

Reciprocal interactions among parietal and occipito-temporal representations support everyday object-directed actions

Everyday interactions with common manipulable objects require the integration of conceptual knowledge about objects and actions with real-time sensory information about the position, orientation and volumetric structure of the grasp target. The ability to successfully interact with everyday objects involves analysis of visual form and shape, surface texture, material properties, conceptual attributes such as identity, function and typical context, and visuomotor processing supporting hand transport, grasp form, and object manipulation. Functionally separable brain regions across the dorsal and ventral visual pathways support the processing of these different object properties and, in cohort, are necessary for functional object use. Object-directed grasps display end-state-comfort: they anticipate in form and force the shape and material properties of the grasp target, and how the object will be manipulated after it is grasped. End-state-comfort is the default for everyday interactions with manipulable objects and implies integration of information across the ventral and dorsal visual pathways. We propose a model of how visuomotor and action representations in parietal cortex interact with object representations in ventral and lateral occipito-temporal cortex. One pathway, from the supramarginal gyrus to the middle and inferior temporal gyrus, supports the integration of action-related information, including hand and limb position (supramarginal gyrus) with conceptual attributes and an appreciation of the action goal (middle temporal gyrus). A second pathway, from posterior IPS to the fusiform gyrus and collateral sulcus supports the integration of grasp parameters (IPS) with the surface texture and material properties (e.g., weight distribution) of the grasp target. Reciprocal interactions among these regions are part of a broader network of regions that support everyday functional object interactions.

Plasma-Activated Polydimethylsiloxane Microstructured Pattern with Collagen for Improved Myoblast Cell Guidance.

We focused on polydimethylsiloxane (PDMS) as a substrate for replication, micropatterning, and construction of biologically active surfaces. The novelty of this study is based on the combination of the argon plasma exposure of a micropatterned PDMS scaffold, where the plasma served as a strong tool for subsequent grafting of collagen coatings and their application as cell growth scaffolds, where the standard was significantly exceeded. As part of the scaffold design, templates with a patterned microstructure of different dimensions (50 × 50, 50 × 20, and 30 × 30 μm2) were created by photolithography followed by pattern replication on a PDMS polymer substrate. Subsequently, the prepared microstructured PDMS replicas were coated with a type I collagen layer. The sample preparation was followed by the characterization of material surface properties using various analytical techniques, including scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). To evaluate the biocompatibility of the produced samples, we conducted studies on the interactions between selected polymer replicas and micro- and nanostructures and mammalian cells. Specifically, we utilized mouse myoblasts (C2C12), and our results demonstrate that we achieved excellent cell alignment in conjunction with the development of a cytocompatible surface. Consequently, the outcomes of this research contribute to an enhanced comprehension of surface properties and interactions between structured polymers and mammalian cells. The use of periodic microstructures has the potential to advance the creation of novel materials and scaffolds in tissue engineering. These materials exhibit exceptional biocompatibility and possess the capacity to promote cell adhesion and growth.

Physical properties of asteroid Dimorphos as derived from the DART impact

AbstractOn 26 September 2022, NASA’s Double Asteroid Redirection Test (DART) mission successfully impacted Dimorphos, the natural satellite of the binary near-Earth asteroid (65803) Didymos. Numerical simulations of the impact provide a means to find the surface material properties and structures of the target that are consistent with the observed momentum deflection efficiency, ejecta cone geometry and ejected mass. Our simulation that best matches the observations indicates that Dimorphos is weak, with a cohesive strength of less than a few pascals, like asteroids (162173) Ryugu and (101955) Bennu. We find that the bulk density of Dimorphos ρB is lower than ~2,400 kg m−3 and that it has a low volume fraction of boulders (≲40 vol%) on the surface and in the shallow subsurface, which are consistent with data measured by the DART experiment. These findings suggest that Dimorphos is a rubble pile that might have formed through rotational mass shedding and reaccumulation from Didymos. Our simulations indicate that the DART impact caused global deformation and resurfacing of Dimorphos. ESA’s upcoming Hera mission may find a reshaped asteroid rather than a well-defined crater.

TEM and X-ray diffraction studies of structure of TiNi SMA treated by low-energy high-current electron beam

Advanced scientific and technological achievements in the surface engineering of TiNi shape memory alloys are closely related with their mechanical performance. Electron-beam treatments could be applied in order to modify surface properties of smart materials and promote stress-induced martensitic transformations. The fundamental issue of electron-beam processing is residual elastic stresses arising from the ultrafast quenching (∼108 K/s) of thin (∼2–4 μm) surface layers. We report the experimental results on phase composition, structure and residual elastic stresses formed in the binary TiNi SMA irradiated by a low-energy (< 25 keV) high-current (∼ 25 kA) electron beam. Microstructure, fracture mechanisms and phase analysis of the as-cast and deformed tensile specimens have been studied by X-ray diffraction and electron microscopy. After electron-beam treatment, both martensitic B19′ and R phases are found in the near surface layer. The X-ray diffraction studies indicate that compressive stresses in the B2 phase of the irradiated TiNi alloy reach –460 MPa. In the fractured specimen (after tensile test) the residual stresses decrease to –160 MPa and release through the B2→B19′→B2 martensitic transformation. In-depth gradient distribution of the defect substructures responsible for the mechanical behavior of TiNi alloys was revealed.

Tailless Information-Energy Metasurface.

Programmable metasurface technology can achieve flexible manipulations of electromagnetic waves in real time by adjusting the surface structure and material properties and has shown extraordinary potential in many fields such as wireless communications and the Internet of Things. However, most of the programmable metasurfaces have a common feature: a tail (electrical wires and DC powers), which is difficult to supply in some particular application scenarios such as canyons and mountains. To eliminate the limitation of DC power supply, the programmable metasurface and wireless power transfer technology are combined to propose a tailless information-energy metasurface (IEMS). The tailless IEMS platform can dynamically control electromagnetic waves without relying on an external DC power supply; instead, the required DC power is provided internally by the IEMS platform itself. In the tailless IEMS experiments, the concept is demonstrated through the dynamic regulation of wireless channels and the wireless transmission of DC power. This work provides a self-powered method for programmable metasurfaces, expands the application scenarios, facilitates the miniaturization of systems, and makes it easy to integrate with other systems.

Optical and microstructural properties of electrodeposited cuprous oxide

The production of hydrogen fuel using photoelectrochemical water splitting method requires semiconductor materials with suitable energy gap, electrical and optical properties. Cuprous oxide is feasible candidate fulfilling many of these requirements to be the photocathode of such devices. In this study, we investigated optical and microstructural properties of cuprous oxide prepared under different temperatures. Microstructure properties were evaluated by statistical, fractal and Fourier methods. Roughness characteristics, Fourier transforms and multifractal characteristics provide consistent information connected with the distribution of surface objects created during sample fabrication. Our methodology is feasible to provide practical insights for the fabrication and monitoring of surface and optical properties of Cu2O and other semiconductor materials.

Remotely Controlled Electrochemical Degradation of Metallic Implants.

Biodegradable medical implants promise to benefit patients by eliminating risks and discomfort associated with permanent implantation or surgical removal. The time until full resorption is largely determined by the implant's material composition, geometric design, and surface properties. Implants with a fixed residence time, however, cannot account for the needs of individual patients, thereby imposing limits on personalization. Here, an active Fe-based implant system is reported whose biodegradation is controlled remotely and in situ. This is achieved by incorporating a galvanic cell within the implant. An external and wireless signal is used to activate the on-board electronic circuit that controls the corrosion current between the implant body and an integrated counter electrode. This configuration leads to the accelerated degradation of the implant and allows to harvest electrochemical energy that is naturally released by corrosion. In this study, the electrochemical properties of the Fe-30Mn-1C/Pt galvanic cell model system is first investigated and high-resolution X-ray microcomputed tomography is used to evaluate the galvanic degradation of stent structures. Subsequently, a centimeter-sized active implant prototype is assembled with conventional electronic components and the remotely controlled corrosion is tested in vitro. Furthermore, strategies toward the miniaturization and full biodegradability of this system are presented.

Flexible Pressure Sensor Based on Carbon Black/PVDF Nanocomposite

A piezoresistive flexible pressure sensor was fabricated using carbon black and Poly (vinylidene fluoride) (CB/PVDF) composite. The conductive CB/PVDF composite was prepared by a wet-cast method and deposited onto a flexible polyethylene (PE) substrate. The surface morphology, crystal structure, and material properties were studied using SEM and X-ray diffraction methods. This flexible pressure sensor was tested in a wide pressure range of about 0 - 76 kPa, and its response time was less than 0.43 s. The sensitivity, response time, and recovery time were studied for different pressures and vibration modes. The repeatability and reproducibility characteristics of the sensors were studied, and it was found that the sensors exhibited excellent characteristics. The sensor was subjected to different loading and unloading pressures, and the resistance of the sensor remained stable, indicating that the sensor had a high degree of reproducibility. Owing to its flexible properties and the materials used, the proposed device can be applied in the next generation of smart sensors for biomedical, robotic, and automotive sensing applications.

Geometric attenuation function analysis based on V-grooved surfaces.

In this study, we present a simulation addressing the phenomena of shadowing and masking in TE and TM polarized incident plane waves interacting with V-grooved rough surfaces. Blinn's theory on light attenuation posits that such a rough surface is represented by a symmetric, elongated V-shaped groove cavity, considering only the tilt angles of the slopes. Our numerical analysis considers variables such as polarization (TE or TM), wavelength, tilt, and slant of the incident or viewing direction, as well as the material properties of the rough surfaces, to accurately calculate light attenuation on V-grooved rough surfaces. The findings indicate enhanced precision in the measurement of light attenuation on these complex geometries.

Preparation and Properties of Novel Antimicrobial Polyurethane Materials

Using the pre-polymer method, we created new materials called antimicrobial polyurethane (PU). To analyze the chemical structures of the PU materials, we used various techniques, including Fourier transform infrared (FTIR), 1H-NMR, gel permeation chromatography (GPC), and Differential Scanning Calorimetry (DSC). In addition, we investigated the surface properties of the PU material by scanning electron microscopy (SEM). According to the mechanical assessment, the antimicrobial polyurethane films display good mechanical qualities. We have also tested the barrier and antimicrobial properties of the films, and the results show that these films have good barrier properties and that the antimicrobial polyurethane films have better antimicrobial properties compared to pure polyurethane films. These properties are enhanced as the antimicrobial agent content in the antimicrobial polyurethane films increases.

Structural, optical and magnetic properties of Fe, Co and Co[sbnd]Fe doped SnO2 thin films deposited by a thermionic vacuum arc deposition system

Fe, Co and CoFe doped SnO2 thin films were deposited onto glass, indium tin oxide-coated glass, and Si substrates to investigate the influence of substrate material on the surface and magnetic properties. The motivation of this study is to investigate the magnetic, surface, and optical properties of doped SnO2 semiconductor materials as they vary with different substrate materials. The film surfaces are smooth and compact. Additionally, nano particles were observed. Thin films of SnO2 doped with Fe, Co and CoFe doped SnO2 have a Curie temperature. Magnetization–temperature and magnetization–temperature graphs have shown the predicted magnetic properties. These films have giant magnetization and soft magnetic properties. In separately doped Fe and Co – SnO2 thin films, the M (emu) values are nearly the same. In Co and Fe-doped SnO2 thin films, the M (emu) values for the film deposited onto ITO-coated glass and uncoated glass are nearly the same.

Effect of the Addition of Naringenin Derived from Citrus on the Properties of Epoxy Resin Compositions.

This research concerns the modification of commercially available epoxy resin with flame retardants in order to obtain aging-resistant and antimicrobial polymeric materials with a plant stabilizer dedicated to use in rail transport. Polymer compositions based on epoxy resin, fiberglass fabric, and naringenin were prepared. Naringenin was added as a natural stabilizer at 2, 4, and 8 phr. The materials were subjected to solar aging lasting 800 h. The hardness of the samples, surface energy, and carbonyl indexes were determined, and the color change in the composition after aging was analyzed. In addition, microscopic observations, analyses of mechanical properties, and microbiological tests were performed. The hardness determination showed that the samples retained their functional properties after solar aging. The increase in the polar component of the surface energy of all materials indicated the beginning of the degradation process of the composites. The tensile one-directional tests were carried out for plane samples taken in three directions (0, 90, and 45 degrees referred to a plate edge) before and after the aging process. The addition of naringenin did not affect the functional and surface properties of the epoxy resin-based materials. Polyphenol stabilized polymer composites, as evidenced by the results of carbonyl indexes. Moreover, the obtained samples showed good antimicrobial properties for E. coli and C. albicans in the field of testing the viability of microbial cells in contact with the tested surfaces.

A review on the environment friendly electroplating of Cr (III) &amp; Cr (VI)

Chromium plating process is the most effective way of protecting the base material against hostile environment or improving surface properties of base material. There are several problems with traditional chrome plating. Traditional process uses toxic acid baths and may cause various health conditions. The baths employed contain chromic acid in which the chromium is in the hexavalent state. Hexavalent chromium has been proved to have toxic, mutagenic and cancerogenic effects for human health. As a result, In Europe, the implementation of the reach initiative will increase fees on companies still using Cr (VI) in 2017 and will require action plans to phase out Cr (VI) in the future. This has left the plating industry in a very delicate position with dark future prospects unless new solutions that are both effective and environmentally friendly are discovered. Superchrome Physical Vapor Deposition coating ahead of looming industry regulatory actions that will drive towards the removal of hazardous hexavalent chromium compounds. These new sputtered chromium coatings do not require a protective paint top coat to pass exterior automotive trim specifications. Visually the chromium coatings match those of electroplated decorative chromium in color and appearance.

Thermal analysis for laminated plates with arbitrary supports under non-uniform temperature boundary conditions

This paper aims to investigate thermal behaviors of composite laminated plates with different supports under non-uniform temperature boundary conditions. The thermo-elastic solutions of temperature, displacements, and stresses for the laminated plate with arbitrary layer numbers and thickness are obtained based on the three-dimensional theory of thermoelasticity. By applying the Fourier law of heat conduction and the thermoelastic equations, the state-space equations are established by employing the temperature, heat flux, displacements, and stresses as state variables without the hypothesis of displacement form. The differential quadrature method is introduced to discretize the in-plane state variables. On the basis of the continuities of state variables at the interfaces in the laminated plate, the relationships of temperature, heat flux, displacements, and stresses between the top and bottom surfaces can be derived. By simultaneously considering temperature and mechanical boundary conditions applied to the surfaces of the laminated plate, the initial state variables for temperature, displacements, and stresses can be determined uniquely. The errors in the temperature, displacements and stresses resulting from the differential quadrature method can be eliminated by incrementally augmenting the number of sampling points in the convergence study. The accuracy of the present method is thoroughly verified by comparing the current results with both the finite element solutions and the findings reported in previous literature. Finally, the influences of surface temperature, length-to-thickness ratios, material properties, layer numbers, and support types for the distributions of the temperature field, displacements, and stresses in the laminated plate are discussed in detail.

Evaluating the biocompatibility of ceramic materials for constructing artificial reefs

IntroductionCoastal ecosystems, including reefs, are becoming increasingly threatened as anthropogenic development continues to encroach on intertidal habitats with little initiative to establish ecologically considerate infrastructure. Submerging human-made, shelter-providing structures known as artificial reefs (AR) can contribute to the preservation of these ecosystems. ARs are historically used for promoting the abundance and biodiversity of marine species for aquaculture, conservation, and ecotourism; and are typically made of concretes or metal structures. An AR’s success correlates to its ability to establish a surface layer of microorganisms, such as microalgae and bacteria, known as a biofilm. The productivity of the biofilm can be influenced by material surface properties. It is hypothesized that material pH and porosity affect the rate of biofilm formation.MethodsHere - a range of concrete mixtures were cast and submerged in circulating seawater and mass per surface area of biofilm accumulation was measured to evaluate this theory. These mixtures included standard Portland Cement (PC), PC with admixtures of diatomaceous earth (PDC) and limestone (PLC), fine-aggregate high-performance concrete (DUC), and terra cotta (TER). ARs were manufactured as 38mm tall cylinders, 76mm in diameter, and submerged in circulating seawater to evaluate mass per surface area of biofilm accumulation.ResultsOur results indicate that biofilm formation is directly affected by surface porosity and less-so by pH, as determined by measuring material properties after submersion. We found that the PDC samples were most successful in forming a biofilm despite being more fragile than other concrete samples.DiscussionThis preliminary study provides insight into how different material properties influence the accumulation of biofilm as a starting point for designing ARs. Future work will investigate the long-term performance of such samples in relevant conditions.

Construction of dual receptors imprinted polymers by precise control of sequential assembly efficiency in confined sites to enhance specific separation of adenosine 5′-monophosphate

Sequential assembly strategies are employed to incorporate various monomers, thereby enhancing the specific binding capability of imprinting sites towards the target molecule and ultimately improving the selectivity of molecular imprinted polymers (MIPs). However, the effectiveness of sequential assembly in improving discriminative separation requires further investigation. For the specific functional groups present in AMP molecules, the utilization of confining metal ion sites guided by metal–organic frameworks (MOFs) material can effectively mitigate disordered competition, enhance the efficiency of imprinted assembly, and facilitate the controlled growth of imprinted sites. In this study, we have successfully achieved precise control over the efficiency of sequential assembly in hydrophilic Zr-MOFs nanosheets in order to fabricate dual receptor surface molecularly imprinted sorbents (D-MIPs) for selectively separating AMP. The hydrophilic Zr-MOFs nanosheets (D-PABA) possess a significantly high surface area of approximately 282.52 m2 g−1. The water contact angle of Zr-BTB-FA nanosheets was measured to be 32°, while that of D-MIPs was 25°. The hydrophilic surface properties of materials promote the dispersion of the adsorbent in aqueous solutions and enhance the rapid mass transfer of water-soluble target molecules. Additionally, the half-equilibrium time (t1/2) was found to be 0.578 h. The D-MIPs demonstrate a significant adsorption capacity (286.7 μmol g−1 at 298 K) for AMP compared to other nucleoside analogues, such as dC, dG, dA, ADP and ATP. Additionally, an imprinting factor (IF) of 2.764 was observed for D-MIPs compared to their non-imprinted counterpart. In addition, the selective extraction of 97 % AMP from the spiked diluted biofermentation broth sample can be achieved using D-MIPs. This finding highlights the potential of D-MIPs as an efficient solution for the selective capture of AMP from biological samples.