Plasma Surface Treatment Research Articles

Investigation of the effect of surface roughness and plasma treatment on adhesively bonded aluminium-polyamide hybrid joints

Investigation of the effect of surface roughness and plasma treatment on adhesively bonded aluminium-polyamide hybrid joints

Surface plasma treatment effect on shear strength in adhesively bonded joints with modified addition curing silicone adhesive

Surface plasma treatment effect on shear strength in adhesively bonded joints with modified addition curing silicone adhesive

3D-printable nanocomposite for the production of unique nanotextured surfaces: art-inspired distribution of magnetic nanorods

This study reports the development of printable magnetic nanocomposites designed with a novel nanotextured surface, featuring nanospikes—composed of iron oxide magnetic nanorods—distributed with a subtle vertical alignment tendency, inspired by the Beam Drop Inhotim artwork,termed here “Beam Drop Inhotim Surfaces” (BDIS). The nanorods were synthesized via reflux and hydrothermal routes, then incorporated into a commercial photopolymerizable resin, forming a printable magnetic nanocomposite. It was printed using masked stereolithography (MSLA) 3D printing process, with real-time application of a neodymium magnet-induced magnetic field during photopolymerization—an innovative approach compared to plasma or laser surface treatments used in other studies. Characterizations of the nanorods, photosensitive resin, and nanocomposite, conducted via Fourier-transform infrared spectroscopy, magnetic force microscopy, scanning electron microscopy, and vibrating sample magnetometry, confirmed successful nanocomposite production without compromising printability, enabling a unique nanotextured surface.Graphical

Advanced electrical characterization of low-temperature plasmas for wafer-to-wafer bonding processes

Abstract Plasma-Activated Wafer Bonding (PAWB) is an advantageous technique to enable low-temperature annealing of fusion-bonded substrates while maintaining high bonding energy. The use of plasma surface treatments in wafer-to-wafer (W2W) bonding enables new device integration schemes, for example in hybrid bonding applications. Despite the technological relevance and wide usage, these processes are often insufficiently characterized and understood at the fundamental level. This work presents the plasma’s electrical properties influence on plasma treated single substrates, as well as thermally annealed wafer pairs for a set of different process conditions. Installation of current-voltage probes which measure the electrical current, voltage and their respective phase angle at each electrode, enables precise characterization of the plasma process. The obtained plasma-specific parameters can be correlated with resulting oxide growth, wafer warpage and bonding energies. This approach potentially allows for enhanced process control and an improved understanding of plasma-related phenomena in the wafer bonding industry.

Surface treatment strategies for improving adhesion of PEDOT:PSS coatings on aerospace fiber composites

Abstract Fiber-reinforced polymer matrix composites (FRCs) offer advantages such as high strength-to-weight ratio, low density, and cost-effectiveness. However, their limited electrical and thermal conductivity poses challenges in applications such as lightning protection, electromagnetic shielding, and radar absorption. In this study, the effect of PEDOT:PSS content as a coating on layered composites to enhance electrical conductivity and adhesion properties is systematically investigated for the first time. This study explores alternative methods to enhance conductivity, focusing on the adhesion stability of the conductive coating PEDOT:PSS on aramid, carbon, and glass FRCs. Three surface treatment methods—plasma treatment (PT), piranha solution treatment (PI), and a combination of GLYMO/APTES (GA)—were tested for their effects on surface energy and adhesion strength. FTIR spectroscopy revealed significant changes in surface bonds, indicating improved adhesion through new chemical interactions. Contact angle measurements showed improved wettability, with plasma and GA treatments yielding the best results. Peeling tests demonstrated minimal changes in electrical resistance after repeated cycles for plasma- and GA-treated surfaces, highlighting their durability. Cross-cut adhesion tests confirmed that plasma-treated surfaces exhibited the strongest adhesion. This study contributes to the understanding of surface coating techniques to enhance the electrical performance and durability of FRCs, with implications for aerospace, defense, energy, and other industries.

Dynamic study of streamer interaction with fluidized particles in a plasma fluidized-bed system

Exploration of the interaction dynamics between plasma and fluidized particles in a plasma fluidized-bed holds practical importance for elucidating the mechanism of plasma treatment of powders. In this study, we employed a 2D fluid model to investigate the effects of particle diameter, dielectric constant, and inter-particle spacing, with the primary aim of simulating the specific consequences of variations in particle size, material type, and gas-to-powder ratio (GPR) on the powder processing effect. The results indicate that particles with diameters below 300 μm exert less impact on streamer propagation, enabling complete plasma wrapping of the particle surface (100%). However, particles with a diameter of 400 μm induce branching, leading to a reduction in the treatment area to 46%. These observations imply a critical particle size range of 300–400 μm for achieving effective plasma treatment of the fluidized particles. Plasma treatment ensures a comprehensive surface coverage on particles with low dielectric constants (εr<4), while particles possessing a higher dielectric constant (εr>8) exhibit a diminished plasma-treated surface area (80%), meaning that longer treatment durations for high dielectric constant materials may be required to achieve a comparable treatment effect. Furthermore, as the inter-particle spacing increases from 10 to 500 μm, the plasma-treated surface area undergoes an initial increment, followed by a subsequent reduction. Notably, at 300 μm spacing, the streamer channel displays a root-like branching pattern, leading to a substantial expansion of the plasma-treated surface area. This indicates that an optimal GPR in the fluidized-bed system can enhance the powder treatment effect.

The Use of Vacuum Plasma Surface Treatment to Improve the Hydrophilicity and Wettability of Bone Graft Substitutes and Resorbable Membranes: An In Vitro Study.

Background/Objectives: We wished to evaluate in vitro whether vacuum plasma surface treatment of bone graft substitutes and resorbable membranes could improve the hydrophilicity and wettability of the tested materials. Methods: A total of 28 sterilized samples were considered for this research and divided into three groups. Six samples were used for the SEM-EDS analysis. The other 22 samples were randomly assigned into the test (plasma-treated, n = 11) and control (no treatment, n = 11) groups. Vacuum plasma surface treatment was performed in the test group before the SEM-EDS analysis using the ACTILINK reborn with a material holder (Plasmapp Co., Ltd., Daejeon, Republic of Korea). Plasmatreat (Plasmatreat, Steinhagen, Germany) inks were used to evaluate the differences in the hydrophilicity between the test and control groups. The outcome measures were the absorption time, wettability grade, and grade of decontamination after different time cycles. Results: After the vacuum plasma surface treatment, the absorption time of the inks statistically decreased in all of the subgroups (p < 0.05), while the wettability grade increased. The SEM-EDS analyses showed an increased reduction rate of carbon impurities after up to three vacuum plasma surface treatment cycles. Furthermore, the SEM-EDS analysis did not reveal any areas of damage caused by the multiple treatments. Conclusions: Within the limitations of this in vitro study, the vacuum plasma surface treatment increased the hydrophilicity and wettability of the tested biomaterials. Particle bone graft and bone blocks should be treated using longer time programs. Further well-conducted randomized clinical trials with sample size calculations are needed to confirm these preliminary results.

Controlling Plasma-Functionalized Fillers for Enhanced Properties of PLA/ZnO Biocomposites: Effects of Excess l-Lactic Acid and Biomedical Implications.

Plasma surface treatment of ceramic particles has emerged as a promising approach for developing biocomposites intended for use in tissue engineering applications. Introducing functional groups on particle surfaces promotes changes in material surface properties, enhancing adhesion, biocompatibility, and reactivity. It can also mitigate degradation during the processing of polymer matrices in composite materials. Therefore, carefully choosing the functionalizing agent responsible for generating the functional groups and selecting appropriate functionalization parameters are significant steps in the plasma surface treatment process. However, in a tissue engineering context, an excess of the functionalizing agent can be harmful, increasing cell toxicity and inhibiting the stimulation of cell growth, consequently delaying or even hindering tissue regeneration. This article examines how the functionalizing agent excess of l-lactic acid (LA) applied in the plasma surface treatment of the filler affects the thermal, rheological, biological, and wettability properties of poly(lactic acid) (PLA) and zinc oxide (ZnO) biocomposites. The investigation reveals that the surface treatment effectively mitigated the catalytic effects of ZnO on PLA degradation during melt processing, regardless of the excess functionalizing agent. There was minimal impact on the material's rheological, thermal, and wettability characteristics, but the LA residue significantly influenced cell proliferation and the biological response. These findings show the importance of removing excess functionalizing agents to obtain biocomposites suitable for tissue engineering applications.

Hysteresis Improvement of Low-Temperature Polycrystalline Silicon Thin-Film Transistors by N2O Plasma Surface Treatment

We investigated the effects of O2 annealing and N2O plasma surface treatment on polycrystalline silicon (poly-Si) to improve hysteresis of low-temperature polycrystalline silicon (LTPS) thin-film transistors (TFTs). The O2 annealing surface-treated LTPS TFTs exhibited a reduction in the subthreshold swing (SS). However, hysteresis improvement was not significantly observed compared to the non-treated LTPS TFTs. However, the N2O plasma surface-treated LTPS TFTs exhibited a greater reduction in SS and hysteresis improvement than the O2 annealing surface-treated LTPS TFTs. These results originated from the reduction of trap states at the interface between poly-Si and the gate insulator. Compared to O2 annealing surface treatment, N2O plasma surface treatment makes the interface more stable because oxygen passivates the trap states and diffuses into poly-Si. However, as radio-frequency (RF) power increased, SS and hysteresis characteristics degraded due to ion bombardment. Consequently, we improved the hysteresis of LTPS TFTs through N2O plasma surface treatment on poly-Si by optimizing the RF power conditions.

Enhanced electrochemical properties of hard carbon anode derived from phenolic resin modified via an oxygen-induced plasma surface treatment for lithium-ion batteries

Enhanced electrochemical properties of hard carbon anode derived from phenolic resin modified via an oxygen-induced plasma surface treatment for lithium-ion batteries

Recoating performance of fresh and weathered wood surfaces through atmospheric dielectric barrier discharge plasma activation

ABSTRACT This study investigated the effectiveness of non-thermal atmospheric dielectric barrier discharge (DBD) plasma activation on the recoating performance of fresh and weathered spruce wood surfaces, examining both uncoated and coated samples exposed to natural weathering. Results showed that film-forming coatings effectively preserved the wood’s aesthetic appearance, despite slight darkening after recoating. Plasma treatment induced significant chemical changes, creating oxygen-containing functional groups that improved surface activation and wettability. The highest hydrophilicity occurred on uncoated, plasma-treated surfaces, where water droplets disappeared within 60 seconds. Plasma also reduced the initial contact angle of water droplets on surfaces coated with waterborne and solventborne film-forming coatings and Tung oil, enhancing their performance. Weathering increased surface roughness, especially in uncoated samples and those with Tung oil, while solventborne and waterborne coatings offered better resistance to photodegradation. Microscopic analysis of recoated samples confirmed that film-forming coatings protected the wood from discoloration and cracking, although weathering weakened their adhesion. Tung oil recoating provided better long-term hydrophobicity for fresh surfaces, unaffected by plasma pre-treatment. Overall, atmospheric plasma activation was found to be an effective, sustainable pretreatment method that enhanced recoating performance, particularly for film-forming coatings, and extended the durability of coated wood products exposed to environmental conditions.

Improved Adhesion and Biocompatibility of Chitosan-Coated Super-Hydrophilic PVC Polymer Substrates for Urothelial Catheters.

Chitosan is a water-soluble polysaccharide with good adherence to negatively charged surfaces and reported antimicrobial and anti-inflammatory properties. Coating the surfaces of medical devices with chitosan is a promising strategy for harnessing these benefits. However, the surface properties of commercial polymers need to be altered to enable the bonding of thin chitosan films. In this study, the adhesion of chitosan onto plasma-treated polyvinyl chloride (PVC) and the metabolic activity of urothelial cells on chitosan-coated medical-grade PVC used for the synthesis of urinary catheters were evaluated. To improve the adhesion of chitosan onto the PVC catheters, PVC samples were made "super-hydrophilic". PVC substrates were briefly treated with a powerful hydrogen plasma and weakly ionised oxygen plasma afterglow to obtain a chlorine-free surface film, which was rich in oxygen functional groups, followed by incubation of the plasma-treated substrates in an aqueous solution of chitosan. Then, urothelial RT4 cells were seeded on the treated and untreated PVC substrates, and their metabolic activity, confluency, and cell morphology were examined. X-ray photoelectron spectroscopy was used to measure the nitrogen concentration, which corresponded to the chitosan concentration on the substrate. The results showed that the substrates were uniformly covered by a thin layer of chitosan only on plasma-treated surfaces and not on untreated surfaces. Moreover, the chitosan coating provided a stimulated environment for cell adhesion and growth. In conclusion, the chitosan-coated super-hydrophilic PVC substrate shows potential to improve the overall performance and safety of medical devices such as urinary catheters.

Modification of Pure Zinc Surface for Biomedical Applications: The Effect of Oxygen Plasma Immersion Ion Implantation on Tuning the Degradation Rate

Abstract Zinc is a high-potential metal for biodegradable implants. The study of the surface properties, even if at a fundamental level, is of central importance because the surface is the place where electrochemical, physical, and biological interactions take place; this is critical especially for biomedical applications, in which these interactions affect each other. The present work investigates the effect of low-energy oxygen implantation, in the range of − 1 to − 5 kV, for different durations on commercially pure Zn, whose surface had been mechanically polished. The characterization of the as-received and implanted surface was carried out with standard and high-resolution electron microscopy, energy dispersive X-ray spectroscopy, sessile drop contact angle, X-ray photoelectron spectroscopy, and potentiodynamic tests. The plasma-treated surface showed distinct features related to the process parameters, such as the formation of surface waves and oxide agglomerates. The formation of an O-rich layer with specific morphological features was responsible for a slight modification of the corrosion rate, found to be generally lower for longer-time implanted samples being, for instance, ~ 78 ± 26 μm year−1 for samples implanted applying − 1 kV for 60 min compared to that of untreated samples, which is ~ 135 ± 9 μm year−1.

Plasma treatment can efficiently increase the attachment of pancreatic circulatory tumor cells to the surface

Pancreatic cancer ranks as the fourth most common cause of cancer-related fatalities globally, with a notably low 5-year relative survival rate. We need to immediately develop fast, dependable, and noninvasive diagnostic techniques that can accurately identify pancreatic cancer at an early stage. The research project created a straightforward but effective method for detecting and increasing the amount of tumor cells that could bind to polystyrene (PS) well plates. To significantly improve the adhesion of the pancreatic cancer cell line PANC-1 on PS well plates, a 5-min exposure to high-power oxygen plasma was implemented. This treatment caused a significant increase in surface energy and roughness. Surface characterization was assessed by utilizing an atomic force microscope and X-ray photoelectron spectroscopy. Water contact angle measurement is used to assess the level of wettability present on the treated surface. To determine how well the circulatory tumor cells (CTCs) model adheres to a plasma-treated surface (PTS), appropriate amounts of mCherry-labeled PANC-1 cells are mixed into a sample of blood cells to mimic clinical conditions. After applying plasma treatment, the experiment achieved a 96% success rate in binding at 2 h, specifically for the PANC-1 cell type. Moreover, the platform demonstrated a considerable ability to attach to cancerous cells compared to non-cancerous cells found in blood. To summarize, this study has shown that non-thermal plasma treatment could be a novel and efficient method for the better adhesion of pancreatic cancer cells, with the benefits of being cost-effective and quick. It is necessary for additional research to be conducted to confirm the clinical efficacy of the method.

Multiple‐Repeated Plasma Surface Treatments for Significantly Improving Bonding Performance of Metal‐Carbon‐Fiber‐Reinforced Thermoplastic Polymer Dissimilar Adhesive Joints

This work investigates how multiple‐repeated plasma surface treatments can significantly enhance adhesively bonded metal‐carbon‐fiber‐reinforced thermoplastic polymer (CFRTP) dissimilar joints, a topic that has been rarely investigated compared to other parameters during the plasma treatment process. By conducting double cantilever beam tests on adhesively bonded AA6061‐carbon‐fiber‐reinforced polyphthalamide (CFRPPA) dissimilar joints, it is shown that the average Mode I specific fracture energy after 20 repetitions of the same plasma treatment, using processing parameters without noticeably changing surface roughness, can be improved and saturated up to almost 2000% compared to non‐treated joints and almost 240% compared to a single plasma treatment commonly used in the literature. The improvement can be attributed to the enhanced chemical bonding at the CFRPPA‐adhesive interface. This study is important for achieving strong bonding performance of CFRTP‐related structural joints using multiple plasma treatments, a simple and effective method.

Investigation of the effects of atmospheric pressure plasma on polypropylene automotive bumper surface and its paintability with and without primer

AbstractAmong commercial polymer materials, polypropylene (PP) is the most preferred in the world. Low‐density materials such as polymers and polymer composites are increasingly used to produce lighter structures. In the automotive industry, these parts are used for painting. Due to the non‐polar surface chemistry of PP, PP surfaces have low surface energy, which causes weak bonds in coating, painting, and bonding processes. Therefore, various physical and chemical processes are used to increase the surface energy of PP first, and then the surface is prepared with a primer before painting. However, the primer material and surface treatments used have disadvantages such as extra cost, being harmful to the environment, and the use of fossil fuels. Atmospheric pressure plasma (APP) surface treatment has recently become an alternative to traditional methods. In this study, the chemical and physical changes caused by APP surface treatment on PP surfaces were examined, the effects of process parameters were investigated, and the paintability of surfaces with and without primer was investigated.Highlights Primerless painting feasibility per standards is under investigation. Eco‐friendly alternatives to traditional pre‐paint treatments are under study. Polypropylene surface properties' effects on painting are under study. Optimal atmospheric pressure plasma parameters for painting are determined.

Enhancing Interfacial Adhesion in Kevlar and Ultra-High Molecular Weight Polyethylene Fiber-Reinforced Laminates: A Comparative Study of Surface Roughening, Plasma Treatment, and Chemical Functionalization Using Graphene Nanoparticles

Enhancing Interfacial Adhesion in Kevlar and Ultra-High Molecular Weight Polyethylene Fiber-Reinforced Laminates: A Comparative Study of Surface Roughening, Plasma Treatment, and Chemical Functionalization Using Graphene Nanoparticles

The effect of glow discharge air plasma surface treatment on mechanical properties of natural fiber reinforced-epoxy sustainable biocomposites

ABSTRACT Natural fiber composites are widely explored sustainable alternative to conventional composites in many applications. However, since they are weak compared to conventional composites, various surface treatments are adopted to improve their overall mechanical properties. The effect of glow discharge air plasma treatment of banana and pineapple leaf (PALF) natural fibers is investigated and presented in this study. Fibres were treated for different time periods, their surface were analysed, and composite laminates with standalone and hybrid were fabricated. Tensile, flexural and impact tests in different combinations of reinforcements were carried out. Spectroscopic, thermal and microscopic characterisations like Fourier-transform infrared spectroscopy (FT-IR), X-Ray diffraction (XRD), Thermogravimetric analysis (TGA), Field Emission Scanning Electron Microscopy (FESEM) were used to study the fibre surface, 3D digital microscope was used to study the fractography and a water absorption test was carried out to study the hydrophilicity were carried out to characterise the fibre surface and the laminates. Significant variations in thermal stability and improvements in tensile strength (even up to 275%) and flexural properties were observed. This investigation revealed the cause of the same was due to the enhancement in crystallinity, mechanical interlocking and improved fibre-matrix adhesion, which was evident from characterizations.

Plasma Treatment of Metal Surfaces for Enhanced Bonding Strength of Metal-Polymer Hybrid Structures.

The adhesion between metals and polymers plays a pivotal role in numerous industrial applications, especially within the automotive and aerospace sectors, where there is a growing demand for materials that are both lightweight and durable. This study introduces an innovative technique to improve the adhesion between a metal and a polymer in hybrid structures through the synergistic use of anodization and plasma treatment. By forming a nanoporous oxide layer on aluminum surfaces, anodization enhances the interface for polymer binding. Plasma treatment further augments the surface properties by increasing the concentration of functional groups, thus allowing better polymer infiltration during the 3D printing process. Comprehensive analyses, including X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, and contact angle measurements confirm the substantial enhancement in the bonding strength achieved through this method. Additionally, cross-sectional analysis via focused ion-beam etching provides a detailed view of polymer integration into the treated layers. The findings suggest significant potential for these surface modification strategies to advance the development of lightweight, robust composites suitable for use in sectors such as automotive, aerospace, and consumer electronics.

Rate coefficients for Vibrationally Inelastic Transitions of the O(3Pg)+O2(3Σ-g, v) System on the O3 Ground Electronic State Potential Energy Surface at 100-1000 K

The v&gt;v′ rate coefficients for the vibrationally inelastic collisions of O atoms with O2 molecules are presented for vibrational quantum numbers v from 0 to 8 and temperatures from 100K to 1000K. State-to-state rate coefficients were computed theoretically using an ab initio O–O2 interaction potential for the ground state of O3 and the final rate coefficients are obtained by summing the state-to-state rate constants over final rotational states and averaging over an equilibrium Boltzmann distribution of relative translational energies and initial rotational states at temperatures of interest in plasma processes. The rate constants obtained are compared with available quasi-classical calculations. The coefficients obtained are required in the modeling of many industrial processes such as plasma etching, surface treatment, plasma sterilization, and medicine.