Surface Modification Of Materials Research Articles

Remarkably enhanced corrosion performance of 316 L stainless steel via laser powder bed fusion thin-layer deposition

This study addresses the demand for on-demand repair and surface modification of conventional materials using advanced technology like laser powder bed fusion (L-PBF). The swift repair and enhancement of 316 L stainless steel surfaces are essential for various applications, especially in corrosive environments where component reliability and longevity are critical. This work aims to explore the improved corrosion properties of conventional 316 L using L-PBF by depositing a limited number of layers. It has been found that with a single- and double-layer deposition the corrosion resistance is improved significantly compared to that of the conventional 316 L. The pitting resistance of the 6-layer L-PBF deposit is comparable to the bulk counterpart.

Mercury Chalcogenide Colloidal Quantum Dots for Infrared Photodetectors

In recent years, mercury chalcogenide colloidal quantum dots (CQDs) have attracted widespread research interest due to their unique electronic structure and optical properties. Mercury chalcogenide CQDs demonstrate an exceptionally broad spectrum and tunable light response across the short-wave to long-wave infrared spectrum. Photodetectors based on mercury chalcogenide CQDs have attracted considerable attention due to their advantages, including solution processability, low manufacturing costs, and excellent compatibility with silicon substrates, which offers significant potential for applications in infrared detection and imaging. However, practical applications of mercury-chalcogenide-CQD-based photodetectors encounter several challenges, including material stability, morphology control, surface modification, and passivation issues. These challenges act as bottlenecks in further advancing the technology. This review article delves into three types of materials, providing detailed insights into the synthesis methods, control of physical properties, and device engineering aspects of mercury-chalcogenide-CQD-based infrared photodetectors. This systematic review aids researchers in gaining a better understanding of the current state of research and provides clear directions for future investigations.

Surface modification of dielectric materials by Ar/toluene DBD plasma for flotation and drag reduction

Surface modification of dielectric materials by Ar/toluene DBD plasma for flotation and drag reduction

Multiscale computational fluid dynamics modelling of spatial ALD on porous li-ion battery electrodes

The self-limiting surface reaction characteristic of atomic layer deposition (ALD) makes it ideal for the surface modification of electrode materials for lithium-ion batteries (LIBs). Spatial ALD shows promise as a scalable method for the coating on pre-fabricated electrode sheets. As a strong-coupled multiscale process, various process conditions and microstructure parameters have great influences on the macroscale fluid dynamics and the pore-scale diffusion–reaction process, thus affecting the coating efficiency. This study presents a multiscale numerical model that combines computational fluid dynamics (CFD) with multilevel pore-scale diffusion–reaction kinetics to explore the spatial ALD process on porous LIB electrodes. The dynamic mesh method is utilized to simulate electrode movement. The considerable active surface-to-volume ratio of the porous structure limits the precursor infiltration depth due to the low diffusion rate and inadequate precursor supply. As the electrode velocity increases, an asymmetric distribution of precursor concentration under the injector is observed with a rapid decrease. Elevating both the precursor concentration and inlet gas velocity augments the coating depth by enhancing the supply of the precursor. The experimental data aligns well with our numerical results, verifying the accuracy of the multiscale CFD model. Our observations reveal that a relatively lower operating pressure, around 0.1 atm, compared to 0.01 atm and 1 atm, optimizes the deposition rate along the electrode depth during the half-ALD cycle, especially when the pore size is larger. Electrode porosity of about 0.4 notably improves coating uniformity by elevating the precursor diffusion rate. Predictions show that with a substrate velocity of 0.2 m/s, the coating depth on an electrode having higher porosity at the top compared to the bottom via atmospheric spatial ALD could reach a depth of 38 μm with a precursor utilization of 78 %.

Effect of oxygen plasma-treatment on surface functional groups, wettability, and nanotopography features of medically relevant polymers with various crystallinities

The surface properties of polymeric biomaterials play a crucial role in their biocompatibility and performance. This study explores the application of cold oxygen plasma treatment as a versatile technique for surface modification of polymeric materials with different degrees of crystallinity: crystalline high-density polyethylene (HDPE), crystalline-amorphous poly(chloro‑paraxylylene) (parylene C), and amorphous aromatic polyether-based polyurethane (PU). The investigations focus on the generation of surface functional groups and hydrophilicity, as well as nanotopography. X-ray photoelectron spectroscopy (XPS) analysis confirmed the generation of oxygen-containing functional groups, resulting in controlled wettability (water contact angle), while atomic force microscopy (AFM) showed topography modifications in the nanoscale. At the same time, it was revealed that oxygen plasma treatment did not affect the bulk properties (confirmed by TG and XRD). The effects of the same plasma treatment conditions varied significantly among the different polymers studied, depending on their crystallinity. This was discussed in terms of the preferential etching of amorphous regions in the polymeric structures. The findings emphasize the advantages of oxygen plasma treatment for tailoring the surface properties of polymeric biomaterials, highlighting its significance for biomedical applications.

Development of Graphene-Based Functional Coating for the Surface Modification of Textiles

The objective of the presented research is to improve the ballistic performance of para-aramid woven fabric by deposition of graphene coatings directly on woven textile substrates. The improvement of mechanical properties of the ballistic fabric is attributed to the formation of a highly ordered layered structure and the efficient load transfer between the fabric fibers and the graphene nanosheets. The results of deposition of layered graphene coatings on woven textiles are discussed here. The pristine graphite directly subjected to a solvent treatment in this work, which resulted in the production of exfoliated graphene sheets in the form of a dispersion that allow immediate utilization obtained dispersion for deposition on the para-aramid samples. In order to prepare the dispersion, graphite flakes were first dispersed into liquid media followed by graphite intercalation (division into microlayers) and nano-layers exfoliation. Dipolar aprotic organic solvent DMAc (N,N-Dimethylacetamide) and Cyrene (Dihydrolevoglucosenone) as a bio-based alternative for dipolar aprotic solvents were used as main components of liquid media. At the final stage, a stable dispersion of isolated flakes by using two types of liquid medium was obtained. To study the effects of dip coating and rolling parameters, six kinds of samples with different pull-out speeds and compression ratios were prepared, and their functional properties were measured and compared.

Carbon-infiltrated carbon nanotubes inhibit the development of Staphylococcus aureus biofilms

Staphylococcus aureus forms biofilms that cause considerable morbidity and mortality in patients who receive implanted devices such as prosthetics or fixator pins. An ideal surface for such medical devices would inhibit biofilm growth. Recently, it was reported that surface modification of stainless steel materials with carbon-infiltrated carbon nanotubes (CICNT) inhibits the growth of S. aureus biofilms. The purpose of this study was to investigate this antimicrobial effect on titanium materials with CICNT coated surfaces in a variety of surface morphologies and across a broader spectrum of S. aureus isolates. Study samples of CICNT-coated titanium, and control samples of bare titanium, a common implant material, were exposed to S. aureus. Viable bacteria were removed from adhered biofilms and quantified as colony forming units. Scanning electron microscopy was used to qualitatively analyze biofilms both before and after removal of cells. The CICNT surface was found to have significantly fewer adherent bacteria than bare titanium control surfaces, both via colony forming unit and microscopic analyses. This effect was most pronounced on CICNT surfaces with an average nanotube diameter of 150 nm, showing a 2.5-fold reduction in adherent bacteria. Since S. aureus forms different biofilm structures by isolate and by growth conditions, we tested 7 total isolates and found a significant reduction in the biofilm load in six out of seven S. aureus isolates tested. To examine whether the anti-biofilm effect was due to the structure of the nanotubes, we generated an unstructured carbon surface. Significantly more bacteria adhered to a nonstructured carbon surface than to the 150 nm CICNT surface, suggesting that the topography of the nanotube structure itself has anti-biofilm properties. The CICNT surface possesses anti-biofilm properties that result in fewer adherent S. aureus bacteria. These anti-biofilm properties are consistent across multiple isolates of S. aureus and are affected by nanotube diameter. The experiments performed in this study suggest that this effect is due to the nanostructure of the CICNT surface.

Enhancing oil repellency of electron beam‐grafted polyethylene terephthalate fabric with 2‐(perfluorohexyl) ethyl acrylate monomer via pre‐irradiation

AbstractElectron beam (EB)‐induced graft polymerization is advantageous for the surface modification of fabrics. We investigated the effect of monomer concentration and the addition of alkyl groups on the oil repellency of polyethylene terephthalate (PET) fabrics treated with monomers containing fluoroalkyl groups through EB‐induced graft polymerization via pre‐irradiation. We use 2‐(perfluorohexyl) ethyl acrylate (FEA) and stearyl acrylate (SA(C18)) with long alkyl chains as vinyl monomers to induce reaction with radicals generated from EB irradiation. The weight gain and surface morphology of the PET fabrics change with the FEA monomer concentration. The uniformity of the EB‐grafted PET fabric surface is determined at low monomer solution concentrations. Results of X‐ray photoelectron spectroscopy analysis show that adding 0.1 mol/L of FEA monomer to the EB‐grafted PET fabric yields the highest dodecane contact angle of 93.4° and a surface fluorine concentration of 39.8%. The addition of SA(C18) monomer to the FEA monomer decreases the dodecane contact angle by 77.5° and yields a surface fluorine concentration of 19.1%. EB graft polymerization via pre‐irradiation results in a uniformly treated surface, and stable oil repellency is achieved when using solely the FEA monomer at a lower monomer concentration than that used in a similar irradiation method reportedly previously.

Dynamic co-irradiation techniques: A new method improving the electrical output of TENG by optimizing the charge capture capacity of polypropylene membrane

Triboelectric nanogenerator (TENG) is a new energy device which can convert mechanical energy into electric energy. Its development and application mainly depend on its output performance. Material improvement, structural optimization, surface modification and other methods have proved to be effective in improving the output performance of TENG. However, so far, there is no industrial technology that can both guarantee the high output performance of TENG and realize large-scale production. Here, we are the first to assemble Radiant polypropylene -TENG (RP-TENG), where the Radiant polypropylene friction material was obtained by the dynamic co-irradiation modification technology of polypropylene (PP). Through FT-IR, SEM and other analysis methods, the mechanism of TENG's electrical output improvement is explained from multiple perspectives. With the treatment under the irradiation dose of 28KGy, the current, charge, and voltage of the RP-TENG reaches up to 9.67 μA, 109.06 nC and 220 V, which is about 4.4 times, 2.5 times and 2.2 times respectively that of the TENG assembled by commercial PP. The reason for the improved performance of the RP-TENG is that the high energy of gamma rays can enhance the surface electron density of the material and change the electron transfer ability of the dielectric material. In addition, the grafted amide group makes the surface of the friction material more prone to electron loss. The homomorphic co-irradiation technology can confer better electrical properties on the friction layer, which provides a new means for enhancing the properties of polymer-based TENG.

Characterization of Nanoparticles in Antimicrobial Coatings for Medical Applications—A Review

This review discusses relevant topics concerning the understanding of the characterization of antimicrobial coatings due to powerful antimicrobial nanoparticles in their composition. These coatings are utilized in the surface modification of yarns and materials designed for use in medical and dental applications. Various physical and chemical methods are employed to create these coatings, ensuring the development of efficient, homogeneous, and uniform layers on diverse surfaces and materials. The primary objective is to confer antimicrobial and/or antiviral properties upon these materials. For these coatings to be effective, they must incorporate active compounds that can combat a wide array of microorganisms, including those that have developed resistance to antibiotics. Examples of such active compounds include metallic nanoparticles such as silver, copper, and gold, as well as nanoparticles of metal oxides such as zinc, titanium, and aluminum. Upon the application of these coatings to medical materials, extensive testing and characterization procedures are undertaken, which will be thoroughly detailed in this review. It is crucial to emphasize that the absence of proper characterization and testing of nanoparticles in antimicrobial coatings could lead to the absence of standards, norms, or procedures necessary to safeguard human health and the environment. Despite their widespread application in the medical field, concerns have been raised regarding the potential toxicity of nanoparticles to living organisms. Consequently, this paper provides a comprehensive overview of the current state-of-the-art methodologies for characterizing nanoparticles in antimicrobial coatings, specifically focusing on materials with varying roughness and structures. Additionally, it outlines the issues associated with the potential accumulation of antimicrobial nanoparticles within the human body.

FEATURES OF MODIFICATIONS IN THE RE-SOLIDIFIED SURFACES OF ADVANCED MATERIALS DUE TO HIGH-POWER PLASMA PULSES

The surface modification of advanced materials was studied through a series of repetitive plasma pulses caused tungsten melting. Features of the affected surface layers in reference materials (IGP W, AM W/WTa, Hastelloy, and EUROFER) for both fusion and fission applications were explored after exposure to plasma in the facilities (QSPA, MPC, and PPA) with different durations of plasma pulses. A detailed surface analysis was carried out with Scanning Electron Microscopy. It was found that the plasma treatment led to the formation of a modified layer as a result of the rapid re-solidification of the exposed surface. The fine cellular structures appeared in the re-solidified layers of the irradiated materials, with typical cell sizes ranging from 150 to 500 nm. An increase in the roughness of the exposed surfaces was attributed to the presence of the cracks and re-solidified layer.

Advances in dendritic cell targeting nano-delivery systems for induction of immune tolerance.

Dendritic cells (DCs) are the major specialized antigen-presenting cells (APCs), play a key role in initiating the body's immune response, maintain the balance of immunity. DCs can also induce immune tolerance by rendering effector T cells absent and anergy, and promoting the expansion of regulatory T cells. Induction of tolerogenic DCs has been proved to be a promising strategy for the treatment of autoimmune diseases, organ transplantation, and allergic diseases by various laboratory researches and clinical trials. The development of nano-delivery systems has led to advances in situ modulation of the tolerance phenotype of DCs. By changing the material composition, particle size, zeta-potential, and surface modification of nanoparticles, nanoparticles can be used for the therapeutic payloads targeted delivery to DCs, endowing them with great potential in the induction of immune tolerance. This paper reviews how nano-delivery systems can be modulated for targeted delivery to DCs and induce immune tolerance and reviews their potential in the treatment of autoimmune diseases, organ transplantation, and allergic diseases.

Graphene-containing para aramid fabric coating via surfactant assisted exfoliation of graphite

Based on existing industrial knowledge and equipment, liquid exfoliation is probably the most viable option for expanding graphene practical application fields. The method’s principal attraction is a scalable process where pristine graphite is subjected to a solvent treatment enabling the creation of graphene dispersion suitable for end applications without transition processes. The challenge is that graphene has a limited disperse ability even in solvents suitable for it, which is due to its small mixing potential and strong π-π attraction between two-dimensional graphite structures. The article discusses the possibilities of using an organic biodegradable solvent derived from natural cellulose residues Cyrene (dihydrolevoglikosenone) as a base solvent to create a liquid graphite exfoliation medium. Since the objective of obtaining graphene dispersion suitable for textile surface modification was not achieved, triethanolamine was added as a result of the search for solutions to improve the performance of the liquid medium. Several technological sequences have been developed and a comparative analysis is presented based on stereomicroscopy observations, micrographs, graphene flakes lateral dimension analysis and evaluation of dispersion adhesion intensity on the fibres of para-aramid fabric.

Superb microplastics separation performance of graphene oxide tuned by laser bombardment

Microplastics have been identified as a significant environmental threat to aquatic ecosystems and human health. Consequently, there is an urgent need for efficient separation methods for small-sized MPs. In this study, a super-hydrophilic graphene oxide (GO) membrane is successfully prepared by facilely depositing GO on a microfiltration substrate, without introducing any surface modification materials, especially nanoparticles, which may cause secondary pollution. Laser bombardment reduces GO lamellar size (23.6% of its original size) and creates an abundance of defects and undulating wrinkles, enabling the deposited GO membrane to have more and shorter pathways for water. As a result, the filtration permeance for 10 μm polyvinyl chloride reaches up to 3396 L m−2 h−1 bar−1, a 1–2-order-of-magnitude enhancement compared to the unirradiated GO membrane, and is also superior to most nanoparticle-modified GO membranes. Simultaneously, the labyrinth structure endows the membrane with a high filtration efficiency of approximately 99% for the majority of MPs. This excellent performance remains virtually unchanged after repeated use. The integration of outstanding separation effects and health safety presents opportunities for practical applications in long-term MP-in-water separation.

Study of the deorbit sail damage under the combined effects of atomic oxygen erosion and material defects

In order to help control the spread of space debris and junk, deorbit sail devices have been used for deorbiting techniques; however, this approach is still considered risky due to potential failure or malfunction as it need to be exposed to the harsh space environment for a prolonged period of time, particularly in low-Earth orbit. China has made new strides forward in managing space junk, as it has successfully unfolded a 25-square-meter deorbit sail developed by the Shanghai Academy of Spacecraft Technology in-orbit for the payload capsule of a recently launched rocket. Accordingly in this paper, a full life-cycle modelling based on Monte Carlo method is developed to reveal the damage behavior of the 25-square-meter deorbit sail surface under the combined effects of atomic oxygen erosion and deorbit sail defects. The simulation results show that as the atomic oxygen fluence increases and the material defect width widens, the interaction effect of the two factors becomes more and more pronounced, which decisively influences the erosion rate of the sail surface. Morphological characterization of aluminized film PET material, activated silanisation modified material and plasma-polymerization coating material before and after atomic oxygen erosion combined defects is carried out and the atomic oxygen erosion of the deorbit sail surfaces is quantitatively assessed. The assessment results show that compared to the PET material and activation silanisation surface modification material, the plasma polymeric coated material showed much better flexibility, folding resistance and irradiation resistance to prevent geological fold and to shield from the atomic oxygen erosion in space. The atomic oxygen erosion combined defects assessment method studied in this paper provides valuable reference data for the subsequent serialisation of deorbit sail products and other typical lightweight film materials for space applications.

A novel conductive network surface coated anode material Si/SA-CNTs for lithium ion batteries

Silicon (Si) material is considered the most promising ideal anode material due to its highest theoretical specific capacity of 4200 mAh g−1. However, the large volume changes during the lithiation-delithiation process lead to electrode structure collapsed failure and hinder silicon anode application. To inhibit the volume expansion of silicon anode materials, this paper focuses on the surface modification of silicon-based thin film anode materials. Through the combination of plasma enhanced chemical vapor deposition technology (PECVD) and surface coating modification technology, sodium alginate (SA) coating is introduced on the surface of amorphous Si thin film to obtain Si/SA composite with good cycle performance. Furthermore, by constructing carbon nanotubes on the SA coating layer, Si/SA-CNTs composite was successfully prepared. The initially discharge specific capacity of Si/SA-CNTs is 3716 mAh g−1, and the discharge specific capacity is 2028 mAh g−1 after 200 cycles at 0.5C (1C = 4.2 A g−1). It increased by 1413 mAh g−1 compared with pure Si thin film. At the same time, its discharge specific capacity at 10C is 1726 mAh g−1, showing excellent rate performance. This surface coating modification helps relieve the stress and strain during the charge/discharge process. Meanwhile, the conductive structure enhances the transport of electrons and ions, which effectively improves the electrochemical performance of the Si thin film.

Modification of nonwoven polymer materials for increasing of their filtration and antibacterial properties

AbstractPolytetrafluoroethylene (PTFE), octenidine dihydrochloride (OCT), and zinc oxide (ZnO) were used to modify the polypropylene nonwoven material by the methods of “wet chemistry” and low‐energy electron beam deposition (EBD). The influence of nonwoven material modification on the morphology, chemical composition, filtration, and antibacterial properties was established. The modified material has antibacterial activity against the gram‐positive strain Staphylococcus aureus and against gram‐negative strains of Escherichia coli and Klebsiella pneumoniae (suppression of bacterial growth for materials with OCT was 100%, with ZnO—70%). PTFE application to Aquaspun leads to a significant increase in the contact angle (from 141.3° to 152.7°) and air filtration efficiency (from 78.3% to 83.4%), which provides the barrier properties of the material. It was established that the material obtained using low‐energy EBD demonstrated a more pronounced antimicrobial potential against the tested strains of St. aureus.Highlights The influence of polypropylene nonwoven materials surface modification methods is systematically investigated. Low‐energy electron beam deposition increases antibacterial and filtration properties of nonwoven materials. Surface modification methods increase barrier properties of polypropylene nonwoven materials.

Histological and mechanical properties of laser-melted carbon nanotube-toughened Fe-based amorphous coatings

Abstract Laser melting technology is a new surface fabrication technique, and using laser beams to improve the mechanical properties of iron-based amorphous prepared by laser melting has become a hot topic in current materials research. Firstly, nickel-plated carbon nanotubes were used to improve the toughness of iron-based amorphous coatings, and nickel-plated carbon nanotubes were used to prepare iron-based amorphous composite fusion cladding layers. Then, the iron-based amorphous has good strength, strong wear resistance and corrosion resistance and is a good surface modification material. Finally, considering that the preparation of iron-based amorphous coating by laser melting technology can meet the preparation requirements of fast cooling of iron-based amorphous, the organization and mechanical properties of the iron-based amorphous coating are studied and analyzed by using laser melting technology. The results show that the toughness of the amorphous-1.00 wt% nickel-plated carbon nanotube composite clad layer is 7.67 MPa-m which is 33.4% higher than the amorphous clad layer. The composite clad layer with the addition of carbon nanotubes showed a significant increase in toughness without a significant decrease in hardness, and the prepared nickel-plated carbon nanotube/amorphous composite clad layer had better overall mechanical properties. This study improves the mechanical properties of iron-based amorphous coatings, which is important to improve the problems of decreasing service life and stability of equipment and components caused by corrosion and wear.

Zinc as a potential bio-degradable temporary implant material

This paper discusses the possibility of developing metallic zinc (Zn) and its alloys as temporary bio-implants by improving its properties through alloying, mechanical deformations and surface modifications. Even though the research on Mg and Fe as potential temporary implant materials started over two decades ago, Zn is a comparatively newer candidate in this arena. The scope for Zn-based materials for bio-related applications is immense due to their metabolically essential status, ideal biodegradation rates and the possibility of proper excretion by the kidneys. This paper covers the unique favourable properties of Zn and its alloys, which can be explored for bio-applications, along with its limitations and possible options to overcome the limitations. The mechanical properties of Zn implants can be improved to the set standards of load-bearing applications by alloying and mechanical deformations like extrusion, rolling and severe plastic deformations. As a result, the microstructure of the metal alters by grain refinement, formation and redistribution of intermetallic phases, resulting in enhanced hardness, Young's modulus and elastic modulus of the material. The Zn implant surface can be made fully bioactive and corrosion-resistant by engineering its surfaces with biocompatible polymers, bioactive materials like hydroxyapatite and bio-inductive elements like Si. The biochemical treatments, sol–gel techniques and plasma electrolytic oxidation (PEO) processes are effective for surface modification of Zn-based materials. Alloying, mechanical treatments and surface modification techniques are reported to be effective in improving the function of Zn-based implant materials, as discussed in this paper.

A Low-Temperature Boron-Based Composite Coating for Ni-Rich Li-Ion Battery Cathode with Enhanced Cycle Life and Safety

Due to the continuously aggravating global warming crisis, the aim of reducing CO2 emissions by replacing fossil fuels with clean energy sources has raised the demand for electric vehicles (EVs) and driven research in pursuing high-energy rechargeable lithium-ion batteries (LIBs). For the cathode component, Ni-rich cathode materials such as LiNixCoyMn1-x-yO2 (NCM) have been widely adopted in commercial EVs due to their high specific capacity (~200 mAh/g) and high operating voltage (~ 4V vs. Li/Li+). However, Ni-rich cathode materials are still confronting challenges such as poor cycle stability and safety issues. To tackle these problems, a boron-based surface modification of Ni-rich cathode material (NCM) is achieved via a low-temperature process in this work. The coated NCM shows comparable rate capability but with substantially improved cycle stability. In terms of safety issues (thermal runaway process), the onset temperature of the thermal runaway process in presence of electrolyte is delayed by 40°C while the total heat release and the maximum heat flow are both decreased by over 40%. Post mortem and in situ X-ray characterizations using synchrotron radiation further illustrate the reasons of the enhanced cycle stability and safety. Results show that the boron-based composite coating is able to decrease the extent of reaction between NCM and the electrolyte during both cycling and the thermal runaway process. Our results demonstrate the use of a low-temperature boron-based composite coating as an effective surface modification method of Ni-rich cathode materials to achieve long-life and high-safety lithium-ion batteries.