Impact Of Plasma Treatment Research Articles

Plasma-enhanced SnO2-x thin films on copper current collector for safer lithium metal batteries

Anode-free lithium batteries are a safer and lighter alternative, because they eliminate the traditional host anode for lithium ions, thereby enhancing energy density and reducing the battery weight. However, challenges like dendritic growth and electrolyte decomposition persist, affecting battery lifespan. Here, we present a scalable technique using plasma enhanced chemical vapor deposition (PECVD) of a tin(IV) precursor to directly deposit an artificial solid electrolyte interface (SEI) on the copper current collector. The obtained SnO2-x coatings, modified by oxygen plasma, exhibited remarkable electrochemical properties. X-ray photoelectron spectroscopy (XPS) is employed to examine the surface composition and impact of plasma treatment, while long-term cycling and electrochemical impedance spectroscopy (EIS) confirm battery durability. Scanning electron microscopy (SEM) and contact angle measurements elucidate coating homogeneity, with lithium nucleation overpotential during first cycle providing further evidence for homogeneity during lithium de-/plating.

Impact of Plasma Treatment on Lady’s Finger Seeds for Germination and its Growth

Atmospheric pressure plasma has emerged as a promising technology in various fields, including plasma medicine, agriculture, food safety and storage, and food manufacturing. Plasma treatment has proven to be beneficial in plasma agriculture, as it enhances seed germination, plant growth, and resilience against both abiotic and biotic stresses. Additionally, it can aid in the removal of pesticides, increase biomass, and improve yield. However, the molecular mechanisms underlying the effects of plasma treatment on seed germination and plant growth are not yet fully understood. Therefore, in this study, the authors aimed to investigate the physical and chemical properties of Lady’s finger seeds treated with cold plasma, characterized by 2.86 W dissipative power at 7 kV in an argon environment and electron density of 4.53×1010 cm–3 under atmospheric conditions. The FTIR technique was used to identify the functional groups present in the seed before and after treatment, revealing the presence of C-H, C=O, C-O, and N-O functional groups, as indicated by their corresponding absorption peaks at different wave numbers. The stretching of bonds between elements of the functional groups was observed based on transmittance. Moreover, the treated seeds were germinated, and the physical growth of different parts (root, shoot, and leaf) was measured. The results showed that the growth rate of different parts was higher in the treated seeds than in the untreated.

A study to examine the ageing behaviour of cold plasma-treated agricultural seeds

Cold plasma (low pressure) technology has been effectively used to boost the germination and growth of various crops in recent decades. The durability of these plasma-treated seeds is essential because of the need to store and distribute the seeds at different locations. However, these ageing effects are often not ascertained and reported because germination and related tests are carried out within a short time after the plasma-treatment. This research aims to fill that knowledge gap by subjecting three different types of seeds (and precursors): Bambara groundnuts (water), chilli (oxygen), and papaya (oxygen) to cold plasma-treatment. Common mechanisms found for these diverse seed types and treatment conditions were the physical and chemical changes induced by the physical etching and the cold plasma on the seeds and subsequent oxidation, which promoted germination and growth. The high glass transition temperature of the lignin-cellulose prevented any physical restructuring of the surfaces while maintaining the chemical changes to continue to promote the seeds germination and growth. These changes were monitored over 60 days of ageing using water contact angle (WCA), water uptake, electrical conductivity, field emission scanning electron microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS). The vacuum effect was also investigated to separate its effect from cold plasma (low pressure). This finding offers a framework for determining how long agricultural seeds that have received plasma treatment can be used. Additionally, there is a need to transfer this research from the lab to the field. Once the impact of plasma treatment on seeds has been estimated, it will be simple to do so.

Impact of Plasma Treatment on Coriander Seeds for Germination and Growth

Due to its numerous health advantages, coriander is one of the most used cooking ingredients. This paper describes the coriander plant's germination and growth after plasma treatment. The seeds are treated using the gliding arc for periods ranging from one minute to ten minutes. It is discovered that as treatment time is extended, the temperature of the seed rises while its weight continues to fall. The sixth and ninth days are used to calculate the germination rate. The study shows that the treatment time of plasma on seeds increases the hydrophilicity of coriander seeds. It is found that roots and shoots of seeds treated for ten minutes and eight minutes were significantly longer than the other seeds.

A model for spectroscopic ellipsometry analysis of plasma-activated Si surfaces for direct wafer bonding

In this work, the impact of plasma treatment on Si wafers with native oxide on top was systematically investigated using spectroscopic ellipsometry. A general applicable three-layer optical model structure for ellipsometry data fitting was developed and employed on samples treated with the N2, O2, and N2/O2 mixture plasma. Oxide-growth, amorphization of crystalline Si, and the formation of a transition layer between the SiO2 and the amorphous Si were detected. The estimated thicknesses of produced layers were confirmed by complementary methods, which allow precise ultra-thin layers thicknesses detection, namely, angle-resolved x-ray photoelectron spectroscopy and transmission electron microscopy. The depth-resolved chemical composition and the direct thickness measurements of the produced amorphous structure revealed pronounced elemental gradients and the absence of sharp interfaces. Nitrogen gas used in the plasma process was found to be implanted mainly at the interface of the SiO2/transition layer in the form of Si3N4. However, it was verified that it is feasible to employ one general ellipsometry model consisting of SiO2/transition layer/amorphous Si on crystalline Si for all plasma species due to comparably low Si3N4 concentrations as well as its refractive index n and absorption k similarity to SiO2. Spectroscopic ellipsometry is nondestructive and can be efficiently applied to analyze whole wafers without any sample preparation. It can be concluded that the present approach to ellipsometry model development and verification is well suited for plasma-activated direct wafer bonding processes.

Impact of plasma treatment on solderability of printed circuit boards

Flux is essential in the process of soldering. White flux residues are not only an aesthetic issue, but the inactivated components can cause severe problems. With miniaturization of products in the electronics industry, the short circuits caused by ion migration are more likely to occur during the lifetime of the product. Plasma treatment has been proved to be effective in improving the wettability in case of metal and polymer surfaces. The aim of this study is to investigate the possibility of promoting wettability of pads on printed circuit boards by plasma treatment. PCBs with three different types of surface finishes were investigated before and after plasma treatment. Wettability and solderability were examined by contact angle measurement and wetting balance tester. This method has the potential to reduce the usage of flux during soldering as an alternative surface treatment to create oxide-free metal surfaces.

Safety evaluation of plasma-treated lettuce broth using in vitro and in vivo toxicity models

Cold atmospheric plasma is a promising new non-thermal technology for improving the microbiological safety and shelf-life of food products, particularly fresh produce and minimally processed fruit and vegetables. Limited research has been conducted on the safety of plasma-treated foods for human or animal consumption. This study focuses on basic safety studies by investigating lettuce broth treated with a di-electric barrier discharge plasma device as a fresh produce model in terms of in vitro cytotoxic and mutagenic effects on mammalian cells and its in vivo toxicity on Galleria mellonella larvae. Low cytotoxic effects were detected in vitro and mutagenic events were likely to be spontaneous mutations. However, a strong response of G. mellonella larvae to injection with plasma-treated lettuce broth was observed for 5-min-treated broth, with larvae survival of less than 10%. No significant effects on quality attributes such as colour were detected and only low concentrations of peroxide were generated in the broth. This study highlights the need for more detailed investigations into the impact of plasma treatment on food components and the subsequent in vitro and in vivo effects to ensure safe implementation of plasma technology for the processing of food products.

Surface plasma treatment of the electrospun TiO2/PVP composite fibers in different atmospheres

The impact of plasma treatment in the different atmosphere on the surface of the polymer TiO2/PVP microfibers, prepared by needleless electrospinning technology was investigated.The fibers were treated by a low-temperature plasma-induced surface sintering process by a so-called Diffuse Coplanar Srface Barrier Discharge (DCSBD) in three different atmospheres: oxidative – air, reducing – H2 and inert – N2 atmosphere. The impact of the plasma treatment in different atmospheres on the morphology and chemical composition of the TiO2/PVP microfibers was studied. This type of treatment led to the formation of flexible composite core/shell fibers. For evaluation of the polymer decomposition process and ceramics formation – DSC/TG, GIXD, SAXS analysis and Raman spectroscopy were used. Scanning electron microscopy was applied for the characterization of the morphology and chemical composition of the fiber surfaces. It was found that the thin globular titania-enriched layer was formed on the surface of the fibers, the thickness of which depends on the exposure time. The main aim of this work is to investigate the impact of plasma treatment in the various plasma atmospheres on the morphology and chemical composition of the surface of TiO2/PVP composite nano/microfibers.

Impact of plasma treatment in CH4/N2 on the properties of reduced graphene oxide

The effect of the two-step process on the properties of graphene oxide (GO) is studied. At the first stage, CH4 (or CH2+N2) plasma treatment was performed. The second one was heat treated at a temperature of 650° C. The formation of thin polycrystalline carbon films on the surface of graphene oxide was detected. The ratio of carbon to oxygen concentration corresponds to graphene oxide. Smooth surfaces of the films were detected by an atomic force microscope. Films have lower sheet resistance and higher carrier mobility than reduced GO (rGO) during the same heat treatment. An analysis of the Raman spectra shows that the formed films have larger graphene domains than the rGO. The presence of nitrogen in methane plasma leads to a decrease in the resistance and mobility of carriers in the carbon film.

Plasma CVD/etching of Poly(methyl methacrylate) surface: optical and structural characterizations

Poly (methyl methacrylate) (PMMA) optical polymer surface has been treated in a RF remote plasma system, in three different plasma environments. Firstly, its surface has been coated with a plasma polymerized organosilicon precursor (Hexamethyldisilazane: HMDSN), secondly, PMMA surface has been exposed to oxygen plasma, and thirdly SF6 plasma has been used to treatment PMMA surface. The impact of plasma treatment on PMMA surface properties has been monitored using different characterizations techniques: optical reflectance, wettability by using water contact angle measurement, surface morphology using atomic force microscopy (AFM) and chemical structure using attenuated total reflectance of Fourier transformer infrared spectroscopy (ATR-FTIR). The correlations between the different properties have been discussed. The results revealed the possibility of tuning the optical and wetting PMMA surface properties by plasma surface treatment, according to the induced changes in surface morphology and chemical structure after plasma treatment. Particular interesting results are lowest reflectance after PMMA surface O2 plasma exposure and high hydrophobic surface obtained after SF6 plasma surface treatment.

Impact of plasma treatment on acoustic properties of natural cellulose materials

Low-temperature plasma is widely used in many surface treatment technologies for modifications of the physical properties of different polymeric materials. In the present work, we have examined the modification of acoustical properties of natural cellulose materials (cotton, hemp) by the radio-frequency argon plasma. We have observed an increase of the sound absorption coefficient due to the plasma treatment for certain range of applied powers. An analysis of elementary processes which happened during plasma–material interaction was conducted. Additional analyses related to material characterizations were performed in order to resolve structural and chemical changes of plasma treated materials. The micro-mechanical modification of treated materials, which happened upon the retrieved structural and chemical changes, was related to the modification of its acoustical properties in order to explain the observed effect.

The surface modification by O2 low temperature plasma to improve dyeing properties of Rex rabbit fibers

Dyeability of the fiber plays a very important role in the textile industry. The presence of cuticle scales on the surface of Rex rabbit fibers brings difficulties to dyeing process. In this study, O2 low temperature plasma was used to improve the dyeability of Rex rabbit fibers and the two key parameters including the treating time and discharge power were optimized during O2 low temperature plasma treatment. The impact of plasma treatment on the surface morphology, physical-chemical properties, and dyeing behavior of Rex rabbit fibers using anionic dyes were investigated by a series of characterization methods such as scanning electron microscopy, atomic force microscopy, Fourier transform infrared–attenuated total reflection, and X-ray photoelectron spectroscopy. The surface dyeability and color fastness were studied by K/S measurement and washing fastness, respectively. The influence of O2 low temperature plasma treatment on the mechanical properties of Rex rabbit fibers was inspected by the tensile strength measurement. The wettability of the samples was evaluated in terms of wetting time and contact angle. The O2 low temperature plasma treatment resulted in a dramatic improvement in wettability of Rex rabbit fibers. X-ray photoelectron spectroscopy and Fourier transform infrared–attenuated total reflection analysis show that oxygen plasma treatment led to a significant increase in the content of sulfur oxides and polar groups such as (–C=O, –OH, and –NH2) on the fiber surface and resulted in reinforced wettability, dyeing rate and dyeing fixation of Rex rabbit fibers.

Application of argon plasma sheet in the etching process of calcium carbonate crystals for AFM tests

Abstract This paper presents utilization of argon plasma for gradual etching of calcium carbonate crystals. The plasma treatment has been chosen as it appears to be the technique that enables removal of following material layers, thus, the access to the inside of crystals is possible. Examples of investigations of the morphology and mechanical properties of surfaces of calcium carbonate crystals are presented. The impact of plasma treatment has been verified in terms of roughness and volume changes investigated using atomic force microscopy technique in a multi-step experiment. Therefore, we were able to observe the crystal degradation process, revealing the spatial inhomogeneity of the calcium carbonate crystals resulting from their core-shell structure.

Impact of plasma treatment under atmospheric pressure on surface chemistry and surface morphology of extruded and injection-molded wood-polymer composites (WPC)

The influence of plasma treatment performed at atmospheric pressure and ambient air as process gas by a dielectric barrier discharge (DBD) on the morphological and chemical surface characteristics of wood-polymer composites (WPC) was investigated by applying several surface-sensitive analytical methods. The surface free energy showed a distinct increase after plasma treatment for all tested materials. The analyzing methods for surface topography—laser scanning microscopy (LSM) and atomic force microscopy (AFM)—revealed a roughening induced by the treatment which is likely due to a degradation of the polymeric surface. This was accompanied by the formation of low-molecular-weight oxidized materials (LMWOMs), appearing as small globular structures. With increasing discharge time, the nodules increase in size and the material degradation proceeds. The surface degradation seems to be more serious for injection-molded samples, whereas the formation of nodules became more apparent and were evenly distributed on extruded surfaces. These phenomena could also be confirmed by scanning electron microscopy (SEM). In addition, differences between extruded and injection-molded surfaces could be observed. Besides the morphological changes, the chemical composition of the substrates’ surfaces was affected by the plasma discharge. Infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) indicated the formation of new oxygen containing polar groups on the modified surfaces.

Modulating Plasma-Induced Thiol Chemistry In Liquids

Cold physical plasmas are currently under investigation in various fields of industry and medicine. Clinical trials using plasma for wound healing are well under way. In addition, investigations of plasmas for cancer treatment offer promising findings, too. However, the chemical interactions between plasmas and their biological targets are only partly understood. The complex chemical cocktails generated by plasma can affect various biological structures [1]. A better understanding of these reactions would allow tuning and modulating plasmas for specific tasks, e.g. triggering wound healing or apoptosis cascades. One prevalent impact of plasma on biological targets is the chemical modification of thiol groups, which carry out various critical functions in the human body, such as cell signaling and protein structure formation. As thiols are involved in many regulatory and functional processes in tissues, an in-depth understanding of the impact of plasma treatment on thiols is highly relevant to optimize plasmas for medical applications. To shed light onto these interactions, various thiol-containing model substrates were investigated with different plasma sources [2,3]. Using a normalized target substrate, the impact of the different plasma sources can be compared not by means of a physical characterization but by their chemical impact [4]. Stepwise increase of sample complexity allows monitoring how thiols are affected by plasma treatment in an ever more complex environment. The combination of experimental evidence and MD simulations permit a comprehensive overview of chemical processes induced by plasma treatment. This combined approach allows for a more throughout investigation of modifications on a molecular level and helps to understand fundamental plasma chemistry processes. Knowledge how different targets, ranging from small molecules to various proteins are affected by plasma treatment helps to understand how subsequent cellular responses can be triggered and what cross-reactions might be expected by plasma treatment.

Computational And Experimental Study Of The Impact Of Plasma On The Human Epidermal Growth Factor And Its Implications For Wound Healing And Cancer Treatment

The human epidermal growth factor (hEGF) plays an important role in wound healing as well as in cancer treatment. It is known to trigger chemotaxis, mitogenesis, motogenesis, and cytoprotection, allowing the promotion of cancer growth [1]. On the other hand, exactly these triggers are beneficial for wound healing [2]. Previous studies have shown that cold atmospheric pressure plasma (CAP) treatment of proteins can lead to oxidation, causing structural and conformational changes [3]. In this study, we perform computer simulations and experiments to investigate the impact of plasma treatment on hEGF. Conformational changes with different degrees of oxidation, corresponding to short or longer CAP treatment times, are studied by combining simulation results with Fourier transform infrared spectroscopy. Additional experiments are performed with circular dichroism spectroscopy to verify the simulated conformational changes. The results, being qualitatively in good agreement, indicate a more flexible structure after oxidization, due to conformational changes and breakage of disulfide bonds. Docking simulations reveal that a low oxidation degree does not have a significant influence on the binding affinity of hEGF to its receptor. However, a highly oxidized hEGF exhibits less interaction, probably ultimately affecting cell proliferation by either assisting or inhibiting the process. The results indicate that a low amount of oxidation, comparable to the medical CAP treatment times used for wound healing, does not cause significant changes of the structure of the hEGF protein and thus has only little impact on the interaction of hEGF with its receptor. A significant effect on the structural conformation of hEGF and the binding energy with EGFR can be achieved by higher oxidation degrees, which might ultimately lead to inhibition of cell growth or proliferation. This might be important in cancer treatment by means of CAP, as higher doses of oxidation arrest the cell growth, leading to apoptosis or even necrosis [4,5,6].

Utilization of Plasma Treated Polymeric Macro-Fibers as Reinforcement in Concrete Constructions

Polymeric macro fibers BeneSteel having diameter equal to 480 μm and length 55 mm were treated in low pressure oxygen plasma by different treatment duration from 5 to 480 s to attain the better interaction with cement matrix (focused on both, chemical and physical bond). An effect of realized treatment was examined through fiber surface water wettability observation by direct horizontal optical method enabling contact angle measurements. Next, the pertinent negative impact of plasma treatment on fibers mechanical properties was examined by several methods. It was shown that the most effective plasma treatment duration is up to 30 s. Thus treated fibers exhibited the better wettability by ca. 110 % in comparison with reference fibers, while its mechanical properties were not negatively affected. Finally, reference and 30 s plasma treated fibers were used as randomly dispersed reinforcement in concrete specimens. Mechanical properties of these composites were examined by four-point bending tests. Specimens containing treated fibers exhibited bigger fracture toughness by ca. 30 % beside the reference ones, while the first cracking strength stayed constant in all cases.

Inactivation of Salmonella Enteritidis PT30 on the surface of unpeeled almonds by cold plasma

The contamination of nut products, like almonds, with human pathogens is a reoccurring concern in the food industry. In this study the inactivation of Salmonella Enteritidis PT 30 (ATCC BAA-1045) on the surface of unpeeled almonds by cold atmospheric pressure plasma was investigated. Air, O2, N2, CO2 and 90% CO2 + 10% Ar were used as process gas. Inoculum preparation and inoculation of almonds was done according to the guidelines recommended by the Almond Board of California. Furthermore, impact of plasma treatment on product color was measured. All plasma treatments inactivated Salmonella. Maximum achieved inactivation depends on the used process gas. Air plasma inactivated > 5.0 log10, O2 plasma 4.8 and N2 plasma 2.0 log10 after 15 min treatment. The plasma treatment with air and N2 resulted in a browning of the unpeeled almond's surface color. Whereas the other used plasma did not alter the color considerably. The contamination of raw nuts with human pathogens is an on-going food safety concern. The application of cold atmospheric pressure plasma has a high potential as a gentle technology for the surface decontamination. The results of this study suggest that a cold plasma treatment could be an alternative technology for the pasteurization of almonds. The use of air plasma achieved more than a 5 log10, which is in general required by the U.S. Food and Drug Administration for the approval as an alternative inactivation technology for food products. However, the scale up to commercial treatment levels requires the complete understanding of the involved product-plasma interactions.

Morphology-properties relationship of gas plasma treated hydrophobic meso-porous membranes and their improved performance for desalination by membrane distillation

The impact on performance of the surface energy and roughness of membrane materials used for direct contact membrane distillation are critical but yet poorly investigated parameters. The capacity to alter the wettability of highly hydrophobic materials such as poly(tetra-fluoro-ethylene) (PTFE) by gas plasma treatments is reported in this paper. An equally important contribution from this investigation arises from illustrating how vaporized material from the treated sample participates after a short while in the composition of the plasma and fundamentally changes the result of surface chemistry processes. The water contact angle across the hydrophobic membranes is generally controlled by varying the plasma gas conditions, such as the plasma power, chamber pressure and irradiation duration. Changes to surface porosity and roughness of the bulk material as well as the surface chemistry, through specific and partial de-fluorination of the surface were detected and systematically studied by Fourier transform infra-red analysis and scanning electron microscopy. It was found that the rupture of fibrils, formed during membrane processing by thermal-stretching, led to the formation of a denser surface composed of nodules similar to these naturally acting as bridging points across the membrane material between fibrils. This structural change has a profound and impart a permanent effect on the permeation across the modified membranes, which was found to be enhanced by up to 10% for long plasma exposures while the selectivity of the membranes was found to remain unaffected by the treatment at a level higher than 99.99%. This is the first time that an investigation demonstrates how the permeation characteristics of these membranes is directly related to data from spectral, morphological and surface charge analyses, which provide new insights on the impact of plasma treatments on both, the surface charge and roughness, of PTFE porous materials.

The Impact of Plasma Treatment As A Sustainable and Green Technology on The Supply Chain Management of The Spinning Mills

The Impact of Plasma Treatment As A Sustainable and Green Technology on The Supply Chain Management of The Spinning Mills