Surface Modification Applications Research Articles

L-DOPA-Based Polymer Coatings via Oxidative Radical Polymerization and Their Antifouling Applications.

Bioinspired coatings that mimic the adhesive properties of mussels have received considerable attention for surface modification applications. While polydopamine chemistry has been widely used to develop functional coatings, 3,4-dihydroxyphenyl-l-alanine (l-DOPA), a key component of mussel adhesive proteins, has received less attention because, compared to dopamine, it is relatively difficult to form effective coatings on solid substrates in mildly alkaline solutions. Although several methods have been explored to improve the efficiency of l-DOPA coatings, there is still a need to expand the l-DOPA-based surface chemistry. Herein, we report a simple yet efficient approach to forming poly(l-DOPA)/polymer coatings via radical polymerization with various acrylic monomers. In this one-step, dip-coating process, free radicals generated by the oxidation of l-DOPA either coupled to form poly(l-DOPA) or initiated the polymerization of the acrylic monomers, resulting in polymer coatings on a wide range of substrates. The feasibility of this coating process was confirmed by ellipsometry, contact angle goniometry, X-ray photoelectron spectroscopy, and atomic force microscopy. As a potential application, the antifouling properties of the poly(l-DOPA)/poly(oligo(ethylene glycol) methacrylate) coatings were investigated against Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), showing a significant reduction in bacterial adhesion. We think that this study broadens the scope of l-DOPA-based surface chemistry and provides a new avenue for the development of biomimetic functional coatings in materials science and surface engineering.

Behavior of plasma parameters under mirror and cusp magnetic fields in DC glow discharge – a numerical study

Abstract The plasma parameters in DC glow discharge can easily be controlled by externally applied magnetic field without disturbing internal / built-in process parameters. Though several works have been carried out to study the influence of the magnetic field at different configurations on the plasma parameters, a complete understanding on the behaviour of the plasma discharge under the mirror and cusp fields could not be achieved. Further studies on the same are needed to improve the efficiency of the DC glow discharge system for existing applications and to find the new applications. In this work, a 2D axis-symmetric non-equilibrium plasma model with drift-diffusion approach is developed to study the characteristics of the plasma in DC glow discharge through various plasma parameters under mirror and cusp fields. The effects of current and position of magnetic coils on electric potential, ionization rate, electron temperature and electron number density are predicted and discussed. The distribution of electron number density at various coil currents and positions under both mirror and cusp fields are presented and the operating conditions favorable for applications in surface modification are suggested.

One-step on-chip preparation of nanoparticle-conjugated red blood cell carriers

Red blood cell (RBC)-based carriers have emerged as promising vehicles for drug delivery due to their inherent biocompatibility and biodegradability. Traditional methods for loading nanoparticles (NPs) onto RBC surfaces often involve labor-intensive processes like incubation and multiple centrifugation steps, limiting their practicality and controllability. In this study, we introduce a fully integrated acoustofluidic platform that enables one-step preparation of NP-loaded RBC carriers with controlled modification and on-site purification. By incorporating a high-frequency bulk acoustic wave (BAW) resonator into a microfluidic chip, we utilize acoustic streaming effects to manipulate the movement and interaction of RBCs and NPs within the microchannel. This design allows for precise control over NP loading efficiency by adjusting the input power to the resonator. Experimental results using 200 nm positively charged fluorescent NPs demonstrate that our platform significantly enhances the interaction between RBCs and NPs, achieving efficient and controllable surface loading of NPs onto RBCs. Furthermore, the platform simplifies post-processing by directing excess NPs to waste outlets, eliminating the need for repetitive washing and centrifugation. This acoustofluidics approach not only automates the loading process but also offers high controllability, highlighting its potential for various applications in particle and cell surface modification.

Fabrication of surface-carbonated boron nitride nanosheets and their application as water-based lubrication additives

As a typical two-dimensional layered material, hexagonal boron nitride nanosheets (BNNSs) have high mechanical strength, good conductivity, and excellent lubrication performance, which have great potential as solid nano lubricant additives in tribology. When BNNS is used as a water-based or oil-based lubricant additive, its inherent chemical inertness and poor dispersion stability make it difficult to achieve optimal anti-friction and anti-wear performance. In this paper, a simple and efficient preparation method for obtaining hexagonal boron nitride nanosheets (C-HPC-BNNSs) with surface carbonization modification and excellent dispersion stability in water-based lubricants was proposed. Using hydroxypropyl cellulose (HPC) as a modifier, a wet ball milling process combined with high-temperature carbonization treatment effectively reduced the thickness of BNNSs while uniformly modifying N-doped carbon layers on the surface of the nanosheets. Benefit from the smaller layer thickness of C-HPC-BNNSs, they exhibit excellent dispersion stability in the water-glycol solution and can maintain no significant agglomeration behavior for up to 30 days, which is the basis for the excellent lubrication performance of lubricant systems. In addition, the N-doped carbon layer modified on the surface is beneficial for enhancing the hydrophilicity of BNNSs and synergistically enhances the tribological properties of the material with BNNSs. The test results of the four-ball friction tester show that compared with the pure water-glycol solution and the water-glycol system with added C-HPC-BNNSs, the friction coefficient (COF) and wear volume of the system with added C-HPC-BNNSs could be as low as 0.095 and 1.99 × 10−4 mm3, respectively. This work has positive significance for the preparation, surface modification, and tribological application expansion of two-dimensional layered material BNNSs, which is conducive to further understanding the relationship between.

Mussel-inspired co-deposition of catechol-amine and graphene oxide (GO) modified anion exchange membranes (AEMs) for antifouling

Mussel-inspired co-deposition has many applications in surface modification of polymer membranes. Organic fouling of ion exchange membranes is one of the common issues that hinder electrodialysis treatment of industrial wastewater. In this work, anion exchange membranes were surface-modified by the mussel-inspired co-deposition of catechol-amine and graphene oxide (GO) nanosheets. Results showed that co-deposition with catechol (CA) and m-phenylenediamine (MPD) as reactant monomers rapidly generated modifying layer on the AEM surface. And the addition of GO into co-deposition helped improve the homogeneity and reduce polymer particle aggregation. The synergistic effect of catechol-amine and GO nanosheets was beneficial to form uniform modifying layer with improved hydrophilicity and negative charge density of membrane surface. In eletrodialysis experiments with sodium dodecyl benzene sulfonate (SDBS) as model foulants, GO-CA-MPD-3h modified AEM maintained high desalination rate close to that without folants, indicating good modifying antifouling performance. Mussel-inspired co-deposition of catecholamines and functional materials give new insights into membrane modificatin through a feasible and cost-effective method.

Nanocellulose from Mankamana-3 corncob biomass: Synthesis, characterization, surface modification and potential applications

This study characterizes corncob from the Nepali variety Mankamana-3, an abundantly available agricultural waste, extracts nanocellulose from it, modifies the nanocellulose with copper nanoparticles, and explores its potential application. The corncobs were mechanically processed into fine powder, delignified by base hydrolysis, bleached and then subjected to acid hydrolysis to obtain nanocellulose fibrils. The corncob contained ~38.86 % cellulose, ~22.02 % lignin, ~34.89 % hemicellulose, ~0.97 % moisture, ~3.33 % ash with minimal moisture content (0.97 %). Transmission electron microscopy imaging confirmed nanocellulose fibers with an average diameter of 28.2 ± 2.57 nm. X-ray diffraction results revealed the existence of both cellulose I and cellulose II polymorphs in nanocellulose with 66.55 % crystallinity index (CrI). Further, copper nanoparticles were grown on nanocellulose fibrils, which showed significant antimicrobial activity against E. coli, S. aureus and C. albicans, and prolonged stability in the ambient environment. The corncob biomass-derived nanocellulose could potentially replace conventional inorganic supports for growing various nanoparticles.

Sustained BMP-2 delivery via alginate microbeads and polydopamine-coated 3D-Printed PCL/β-TCP scaffold enhances bone regeneration in long bone segmental defects

Background/ObjectiveRepair of long bone defects remains a major challenge in clinical practice, necessitating the use of bone grafts, growth factors, and mechanical stability. Hence, a combination therapy involving a 3D-printed polycaprolactone (PCL)/β-tricalcium phosphate (β-TCP) scaffold coated with polydopamine (PDA) and alginate microbeads (AM) for sustained delivery of bone morphogenetic protein-2 (BMP-2) was investigated to treat long bone segmental defects. MethodsSeveral in vitro analyses were performed to evaluate the scaffold osteogenic effects in vitro such as PDA surface modification, namely, hydrophilicity and cell adhesion; cytotoxicity and BMP-2 release kinetics using CCK-8 assay and ELISA, respectively; osteogenic differentiation in canine adipose-derived mesenchymal stem cells (Ad-MSCs); formation of mineralized nodules using ALP staining and ARS staining; and mRNA expression of osteogenic differentiation markers using RT-qPCR. Bone regeneration in femoral bone defects was evaluated in vivo using a rabbit femoral segmental bone defect model by performing radiography, micro-computed tomography, and histological observation (hematoxylin and eosin and Masson's trichrome staining). ResultsThe PDA-coated 3D-printed scaffold demonstrated increased hydrophilicity, cell adhesion, and cell proliferation compared with that of the control. BMP-2 release kinetics assessment showed that BMP-2 AM showed a reduced initial burst and continuous release for 28 days. In vitro co-culture with canine Ad-MSCs showed an increase in mineralization and mRNA expression of osteogenic markers in the BMP-2 AM group compared with that of the BMP-2-adsorbed scaffold group. In vivo bone regeneration evaluation 12 weeks after surgery showed that the BMP-2 AM/PDA group exhibited the highest bone volume in the scaffold, followed by the BMP-2/PDA group. High cortical bone connectivity was observed in the PDA-coated scaffold groups. ConclusionThese findings suggest that the combined use of PDA-coated 3D-printed bone scaffolds and BMP-2 AM can successfully induce bone regeneration even in load-bearing bone segmental defects. The translational potential of this articleA 3D-printed PCL/β-TCP scaffold was fabricated to mimic the cortical bone of the femur. Along with the application of PDA surface modification and sustained BMP-2 release via AM, the developed scaffold could provide suitable osteoconduction, osteoinduction, and osteogenesis in both in vitro settings and in vivo rabbit femoral segmental bone defect models. Therefore, our findings suggest a promising therapeutic option for treating challenging long bone segmental defects, with potential for future clinical application.

Coupling effects of micro/nano-scale surface modification and electric current application on fouling resistance and heat transfer

The principle of saving energy and converting waste heat into valuable resources is a core concept. Heat exchange systems are significantly compromised by microbial fouling, which impedes heat transfer and increases energy consumption. This study investigated the coupling effects of micro/nano-scale surface modifications and the application of electric currents as a novel approach to inhibit microbial fouling. Smooth copper surface, electrochemical deposition (ECD) surface, and Nickel-Phosphorus-Polytetrafluoroethylene (Ni-P-PTFE) modified surface were tested and compared. Firstly, we analyzed the average heat transfer coefficient under clean conditions, taking into account different surface characteristics. Then, we employed a series of fouling experiments to evaluate the anti-biofouling performance of smooth copper surfaces, ECD surfaces, and Ni-P-PTFE surfaces. The assessment involved flow cytometry, Scanning Electron Microscopy (SEM) and measurements of thermal resistance. Finally, we investigated the effect of external electric current on microbial fouling mitigation. Results show that the ECD surface exhibited an enhanced heat transfer and a poor fouling resistance, while the Ni-P-PTFE surface demonstrated an excellent fouling resistance and a minimal increase in thermal resistance. The application of a low direct current density at 0.51 mA/cm² significantly reduced microbial viability on all surfaces. A higher electric current can further inhibit microbial adhesion and proliferation, enhancing the anti-fouling capability of the surfaces. Compared to surfaces without electric current, the smooth copper surface, ECD, and Ni-P-PTFE surfaces at 5.1 mA/cm² displayed a reduction in thermal resistance by 45.7%, 36.8%, and 38.1%, respectively. At 51 mA/cm², the reduction in thermal resistance for smooth copper surface, ECD, and Ni-P-PTFE surfaces was 75.7%, 78.2%, and 57.1%, respectively. This comprehensive study has validated the potential of combining micro/nano-scale surface modifications with electric current application as an effective strategy for enhancing heat transfer efficiency and anti-fouling properties of heat exchange systems.

Effect of oxygen on the discharge characteristics of argon doped ethanol plasma jet and its application in surface modification of polyimide films

Effect of oxygen on the discharge characteristics of argon doped ethanol plasma jet and its application in surface modification of polyimide films

Modulating the corrosion performance of magnesium alloys through hydroxyapatite coating

Magnesium and its alloys have attracted attention as medical bone implant materials due to their excellent biocompatibility, bone-like mechanical properties, and degradability. However, the clinical application of magnesium is limited by the fact that it corrodes too quickly in body fluids, leading to premature mechanical failure. Surface hydroxyapatite coatings can significantly reduce the initial corrosion of magnesium alloys, but suffer from the problems of non-dense coatings, many defects and poor adhesion strength to the substrate. In this study, we propose femtosecond laser construction of microemulsion cone structures on the surface of magnesium alloys to significantly enhance the densities and thicknesses of the coatings, as well as to improve the bonding strength of the coatings to the substrate, which ultimately reduces the corrosion rate. The corrosion rate of modified hydroxyapatite coating in simulated body fluid is only 0.146 mm/y, and it has the ability to rapidly induce hydroxyapatite mineralization and promote osteoblast proliferation. Furthermore, the surface morphology, chemical composition, and wettability of the laser-modified Mg alloy were analyzed. It was demonstrated that the microstructure and thin oxide layer formed on the surface of the magnesium alloy could provide more sites for HA nucleation, which promotes the deposition and growth of HA and the existence of a mechanical interlocking effect with the substrate. The application of femtosecond laser surface modification represents a rapid and efficacious approach to enhance the quality of hydroxyapatite coatings. This method has successfully controlled the corrosion rate of magnesium alloys with excellent biocompatibility, thereby overcoming potential obstacles to the use of magnesium alloys in clinical applications.

Electrospun Polymeric Nanofibers: Current Trends in Synthesis, Surface Modification, and Biomedical Applications.

Electrospun polymeric nanofibers are essential in various fields for various applications because of their unique properties. Their features are similar to extracellular matrices, which suggests them for applications in healthcare fields, such as antimicrobials, tissue engineering, drug delivery, wound healing, bone regeneration, and biosensors. This review focuses on the synthesis of electrospun polymeric nanofibers, their surface modification, and their biomedical applications. Nanofibers can be fabricated from both natural and synthetic polymers and their composites. Even though they mimic extracellular matrices, their surface features (physicochemical characteristics) are not always capable of fulfilling the purpose of the target application. Therefore, they need to be improved via surface modification techniques. Both needle-based and needleless electrospinning are thoroughly discussed. Various techniques and setups employed in each method are also reviewed. Furthermore, pre- and postspinning modification approaches for electrospun nanofibers, including instrument design and the modification features for targeted biomedical applications, are also extensively discussed. In this way, the remarkable potential of electrospun polymeric nanofibers can be highlighted to reveal future research directions in this dynamic field.

Wet mechanochemical surface modification of calcite employing an integration of conventional design and analytical hierarchy process

The demand for ultra-fine mineral powders from various industries requires the applications of wet grinding and surface modification. In this study, wet mechanochemical surface modification of micronized calcite (d50 = 4.92 μm) with stearic acid [CH3(CH2)16COOH] was carried out in a planetary ball mill. The seven parameters were specified: ball filling ratio (%), ball size distribution ratio (10 and 15 mm, %), micronized calcite filling ratio (%), pulp solid ratio (wt%), mill speed (rpm), stearic acid dosage (% of micronized calcite) and modification time (min). Then, these parameters were optimized using a conventional experimental design when maximizing the active ratio (%) as a significant value for coated calcite. Besides, the analytical hierarchy process was applied to observe the importance of each parameter. Stearic acid dosage, mill speed, and micronized calcite filling ratio are the top three parameters affecting the active ratio. Next, size distribution, XRF, XRD, SEM, FTIR, TGA-DTA, contact angle, and whiteness measurements were performed on the micronized calcite (MC) and coated micronized calcite (CMC) samples. The final CMC product had a 99.90% active ratio, 2.49 μm mean (d50) particle size, and 101.66o contact angle. Finally, CMC obtained by the surface modification can be used as a filler mineral.

Preparation, Surface Modification, and Building Materials Applications of Calcium Carbonate Nanoparticles

Preparation, Surface Modification, and Building Materials Applications of Calcium Carbonate Nanoparticles

Method and application of surface modification of Cerium dioxide

Airborne pollutants, such as nitrogen oxides (NOx), and waterborne contaminants, including heavy metals, dyes, and other pollutants, pose substantial environmental threats and jeopardize human health. Additionally, certain limitations have hindered the widespread application of some batteries, primarily attributed to elevated operating temperatures and the decreasing use of fossil fuels. In response to these challenges, cerium dioxide (CeO2) nanoparticles have garnered considerable attention due to their unique and advantageous physical and chemical properties. Furthermore, the incorporation of CeO2 into various coating materials has demonstrated the potential to significantly enhance their performance. In the realm of biotechnology, research into CeO2 nanoparticles continues to expand, encompassing a range of applications such as the scavenging of reactive oxygen species (ROS) in biological systems, the development of anti‐inflammatory agents, and cancer research. Nevertheless, in these diverse applications, CeO2 still exhibits certain limitations that hinder the achievement of desired outcomes. The modification of CeO2 nanoparticles presents a promising avenue to address these limitations, thereby improving their overall efficacy. As such, this review aims to comprehensively compare and summarize various methods for the modification of CeO2 nanoparticles, elucidate their practical applications, and provide insights into the potential challenges and future prospects in this field.This article is protected by copyright. All rights reserved.

Superwetting Capillary Tubes: Surface Science under Confined Space.

Capillarity is a crucial and pervasive phenomenon in nature and has found important applications in wearable electronics, medical devices, and miniature energy systems. Capillary tubes are the transport vessels in which the surface wettability plays an essential role in efficient and accurate liquid delivery. However, it remains a challenging issue to tailor and measure the surface wettability inside the tubes in view of the confined space. Herein, recent progress on the surface science under confined space is discussed, with a particular focus on surface modification, wettability evaluation, and advanced applications of the superwetting capillary tubes. This Perspective aims to highlight the emerging opportunities in surface science with spatial confinement toward flexible and portable devices.

A large-scale cold plasma jet: generation mechanism and application effect

Atmospheric pressure cold plasma jets (APCPJs) typically exhibit a slender, conical structure, which imposes limitations on their application for surface modification due to the restricted treatment area. In this paper, we introduce a novel plasma jet morphology known as the large-scale cold plasma jet (LSCPJ), characterized by the presence of both a central conical plasma jet and a peripheral trumpet-like diffuse plasma jet. The experimental investigations have identified the factors influencing the conical and the trumpet-like diffuse plasma jet, and theoretical simulations have shed light on the role of the flow field and the electric field in shaping the formation of the LSCPJ. It is proved that, under conditions of elevated helium concentration, the distributions of impurity gas particles and the electric field jointly determine the plasma jet’s morphology. High-speed ICCD camera images confirm the dynamic behavior of plasma bullets in LSCPJ, which is consistent with the theoretical analysis. Finally, it is demonstrated that when applied to the surface treatment of silicone rubber, LSCPJ can achieve a treatment area over 28 times larger than that of APCPJ under equivalent conditions. This paper uncovers the crucial role of impurity gases and electric fields in shaping plasma jet morphology and opens up the possibility of efficiently diversifying plasma jet generation effects through external electromagnetic fields. These insights hold the promise of reducing the generation cost of plasma jets and expanding their applications across various industrial sectors.

Plasma-based Surface Modification Applications of Biomaterials – A Review

Plasma-based Surface Modification Applications of Biomaterials – A Review

Opportunities and challenges of the nitride coatings for artificial implants: A review

With the continuous development of the economy and society, exacerbated by the growing challenges of an aging population, the demand for orthopedic implants has witnessed a considerable surge. To enhance the performance and lifespan of these implants, the deposition coating on their surfaces has emerged as a pivotal measure. Among the various coating options, nitride coatings have gained prominence due to their exceptional comprehensive properties and application in surface modification for orthopedic implants. This paper presents a succinct overview of the evolutionary trajectory and fundamental properties of materials employed in implants. It traces the progression from inert materials in the early stages to the second and third generations characterized by bioactivity (biodegradability), and currently, the fourth generation featuring bio-gene materials. Subsequently, a meticulous review delves into the detailed application of nitride coatings in the realm of implants, encompassing critical aspects such as mechanics, tribology, corrosion resistance, antibacterial properties, and biological responses. In conclusion, the article offers insightful perspectives on the future of implant coatings. It serves as a valuable reference for researchers engaged in nitride material studies and bio-coating research, providing a rapid and comprehensive understanding of the current research status surrounding nitride coatings for implants.

Dominant role of laser-generated nano-structures on enhancement of interfacial bonding strength by laser surface modification

Laser surface modification has been widely applied to the pre-treatment of material surfaces for interface bonding, however, laser-treated surfaces face an inevitable risk of environmental exposure during engineering application, and it remains unclear how laser-induced modifications change under environmental exposure. This study investigates the robustness of laser-treated aluminum surface under typical atmospheric and aqueous environments at different temperature from −40 °C to 80 °C. Although the carbon elemental content and water contact angle greatly fluctuate with exposure environments from 23 at.% to 33 at.%, and from 0° to 148°, respectively, laser-treated surfaces exhibit stable improvement of ∼25 % in bonding strength compared to untreated condition even after 30 days exposure. Notably, hygrothermal exposure of 80 °C and 95 %RH significantly declines bonding strength by ∼45 %, and this strength degradation is accompanied by 1.8 % increase of carbon elemental content and water contact angle of ∼150°. Results reveal that laser-generated nano-structures play crucial role in strength improvement, instead of carbonaceous contaminants and surface polarity, and nanostructure transformation causes an apparent strength degradation and change of fracture mode from cohesive to interface. This work uncovers the dominant role of laser-generated nano-structures in enhancing interfacial bonding strength, and provides supports for engineering application of laser surface modification.

Application of Plasma Surface Modification and Slide-ring Polymer Networks for Development of Thermally Conductive Composite Materials

Application of Plasma Surface Modification and Slide-ring Polymer Networks for Development of Thermally Conductive Composite Materials