Investigation of blood coagulation effect of nonthermal multigas plasma jet in vitro and in vivo

The extension of shelf-life and enhancement of the safety and quality of fresh-cut ready-to-eat vegetables is an ongoing public health concern. The present study investigated the efficacy of cold atmospheric plasma (CAP) treatment for the decontamination of fresh-cut carrots inoculated with Escherichia coli. An atmospheric plasma jet system operating at 1 kVA was utilized for treatment with varying plasma jet nozzle to sample distances (10-40 mm), exposure times (10-60 s) and either argon or dry air at 3 bar as working gases. It was demonstrated that both working gases achieved more than 4 log reductions in E. coli within 60 s of treatment while maintaining carrot surface temperatures below 50 °C. During 3-week storage at 4 °C, the immediate effects of plasma treatment on quality parameters were found to be minimal, with no significant changes observed in color (ΔE < 3.0) parameters, β-carotene content, ascorbic acid levels, total phenolic content (TPC), or total antioxidant activity (TAA) following either treatment. Additionally, plasma-treated carrots retained their firmness, showing no significant texture loss, whereas untreated controls experienced a firmness decline of approximately 9% by the end of storage. Notably, TPC increased by up to 41%, and TAA increased significantly (p < 0.05) in plasma-treated samples during storage, especially in dry air plasma-treated carrots. These results demonstrated that CAP treatment can be successfully applied for rapid inactivation of E. coli on fresh-cut carrot surfaces while preserving original quality characteristics during refrigerated storage, offering potential as non-thermal preservation technology for fresh produce.

The effect of plasma treatment on strength properties of wood-based composites was studied. Veneers were obtained from beech logs (Fagus orientalis L.) and treated with 3 % of Tanalith E and Celcure AC-500. Two types of gasses (O2 and N2) were tested for plasma treatment. The effect of plasma treatment on bonding shear strength, bending strength and modulus of elasticity of plywood panels were determined according to EN 314-1 and EN 310, respectively. Surface roughness, leaching, decay test against white (Trametes versicolor) and brown rot [Postia placenta (FPRL 280)] and ground contact test of plywood samples were evaluated after plasma treatment. Results showed that plasma treatment with O2 increased the bonding strength of plywood compared to control and treated groups. However, plasma treatment slightly increased the mass losses caused by white rot, but decreased mass losses caused by brown rot in some groups. Regarding leaching test, plasma treatment slightly increased the leaching rate of copper in some groups. Ground contact test revealed that there was no delamination in bonding line on the plasma-treated samples.

Freshwater is only 2.5% of the total water on the Earth and rest is contaminated or brackish. Various physical and chemical techniques are being used to purify the contaminated water. This study deals with catalytic plasma treatment of contaminated water collected from different sites of Faisalabad-Pakistan. A non-thermal DC plasma jet technique was used to treat the water samples in the presence of TiO2 catalyst. The plasma-assisted catalytic treatment introduced some oxidative species (O3, H2O2, HO2−, OH−) in the water. These species reacted with pollutants and cause the degradation of harmful contaminants, especially dyes. The degradation of dye sample during plasma treatment was more pronounced as compared to other samples. pH, conductivity and TDS of dye containing sample decreased after catalytic plasma treatment. The degradation of organic pollutants increased due to presence of several oxidants, such as TiO2, ferrous ions and hydrogen peroxide. FT-IR analysis revealed the degradation of some functional groups during treatment process and confirmed the effectiveness of the process. The residue of the treated samples was consisted of amines, amides and N-H functional groups. XRD analysis showed the presence of Alite, Ferrite, aluminate, Si, S and some heavy metals in the residue. The effect of plasma treatment on activity of gram-negative Escherichia coli (E. coli) bacteria in water was also checked. The bacterial activity was reduced by almost 50% after 2 min of plasma treatment.

The effect of different plasma treatments on the properties of porous SiOCH ultra-low-dielectric-constant (ULK) film have been studied first. The SiOCH ULK films with NH3 only and H2/NH3 plasmas treatments resulted in various degrees of degradation of surface chemical bonds, Si-CH3 and Si-H and electrical properties. Surface roughness of the films with plasma treatments became smoothened. H2/NH3 plasmas treatment caused more SiOCH ULK film structural change and electrical deterioration compared with NH3 only plasma treatment. Moreover, after H2/NH3 two-step treatment, Ebd decreased by 22% as compared with the as-cured film. Afterward, the effect of different plasma treatments on the interfacial bonding configurations and adhesion strengths between porous SiOCH ULK film and SiCN etch stop layer have been investigated. From X-ray photoelectron spectroscopic analyses, interlayer regions of about 10 nm thick with complicated mixing bonds were found at SiOCH/SiCN interfaces. With plasma treatments, especially H2/NH3 two-step plasma, a carbon-depletion region of about 30 nm thick with more Si-O related bonds of high binding energy formed at the interface. Furthermore, the adhesion strengths of the SiOCH/SiCN interfaces were measured by nanoscratch and microscratch tests. For the untreated interface, the adhesion energy was obtained as about 0.22 and 0.44 J/m2 by nanoscratch and microscratch tests, respectively. After plasma treatments, especially the H2/NH3 treatment, the interfacial adhesion energy was effectively improved to 0.41 and 0.89 J/m2 because more Si-O bonds of high binding energy formed at the interfaces. Finally, by exposure to O2-plasma, gold films were oxidized. Gold oxide (Au2O3) has a short halflife of 22 h at 22 ℃ and 166 h at 0 ℃, with an activation energy of dissociation of 57 kJ/mol, indicating instability even at low temperatures. The results of electrical resistance also revealed that the electrical properties are not degraded after O2-plasma cleaning of the surface of gold due to the restoration of elemental gold.

Over the past several decades, orthodontic treatment has been increasingly sought out by adults, many of whom have undergone restorative dental procedures that cover enamel. Because the characteristics of restorative materials differ from those of enamel, typical bonding techniques do not yield excellent restoration-bracket bonding strengths. Plasma treatment is an emerging surface treatment that could potentially improve bonding properties. The purpose of this paper is to evaluate currently available studies assessing the effect of plasma treatment on the shear bond strength (SBS) and failure mode of resin cement/composite on the surface of ceramic materials. PubMed and Google Scholar databases were searched for relevant studies, which were categorized by restorative material and plasma treatment types that were evaluated. It was determined that cold atmospheric plasma (CAP) treatment using helium and H2O gas was effective at raising the SBS of feldspathic porcelain to a bonding agent, while CAP treatment using helium gas might also be a potential treatment method for zirconia and other types of ceramics. More importantly, CAP treatment using helium has the potential for being carried out chairside due to its non-toxicity, low temperature, and short treatment time. However, because all the studies were conducted in vitro and not tested in an orthodontic setting, further research must be conducted to ascertain the effectiveness of specific plasma treatments in comparison to current orthodontic bonding treatments in vivo.

The low bond strength of lithium disilicate (LD) ceramics to dental resin cements remains a critical issue for dental applications because it leads to frequent replacement and causes tooth tissue destruction and consumption. The objective of this study was to examine the effects of atmospheric non-thermal argon plasma (NTP) treatment on LD to improve its micro-shear bond strength (μSBS) with dental resin cements because LD mostly experiences shear stress for its commonly used dental applications as crowns or veneers. Argon plasma treatment was performed on hydrofluoric (HF) acid-etched LD surfaces, and then commercial resin cements were subsequently applied to the treated LD surfaces. The plasma treatment significantly reduced the water contact angle of the LD surface to less than 10° without changing the surface morphology. The μSBS test was performed with cement-bonded LD samples after 24 h and 30 days, as well as after 1000 cycles of thermal cycling. The test results show that, as compared with the untreated controls, 300 s of plasma treatment significantly improved the LD-resin cement bond strength by 59.1%. After 30 days of storage in DI water and 1000 cycles of thermal cycling, the plasma-treated LD samples show 84.2% and 44.8% higher bond strengths as compared to the control samples, respectively. The plasma treatment effect on LD surfaces diminished rapidly as the bond strength decreased to 25.5 MPa after aging in the air for 1 day prior to primer and cement application, suggesting that primers should be applied to the LD surfaces immediately after the plasma treatment. These results demonstrate that, when applied with caution, plasma treatment can activate LD surfaces and significantly improve the SBS of LD with dental resin cements in both short-term and long-term periods.

In this research study, the effects of an atmospheric pressure plasma treatment on the stability of selected colorants (pigments: red lead, vermilion, azurite, verdigris, smalt, ultramarine, raw sienna, vine black, champagne chalk, Bolognese chalk; dye: alizarin red) were investigated. In order to gain knowledge about the effect of a plasma on the more stable part of colorant-binder systems in works of art, binder-free colorants were first investigated. For this purpose, the samples were briefly exposed to an atmospheric pressure argon or air plasma and then stored for several weeks in two different climates: an indoor climate and a humid climate. Slight color changes were recorded in red lead, verdigris, alizarin red, and Bolognese chalk by photometric investigations and evaluation of the color values in the CIEL*a*b* system. Scanning electron microscopy revealed morphological changes in the plasma-treated verdigris samples. With the help of infrared spectroscopy and X-ray diffractometry, it could be shown that the degradation processes of some of the examined colorants were influenced by the preceding plasma treatment. Nonetheless, atmospheric pressure plasma treatment could be of interest in art restoration as a tool for decontamination and surface activation.

Plasma treatment is a kind of environmentally friendly surface modification technology, which has been widely used to modify various materials in many industries. Plasma treatment improves the fiber-matrix adhesion largely by roughening the surface of fibers to increase mechanical interlocking between the fiber and the matrix. For this aim, the effect of atmospheric air plasma treatment on jute fabrics has been discussed in this study. The plasma treatment has been employed at different powers and time intervals. The effects of plasma treatment on fiber properties were revealed by wickability, surface roughness, fiber tensile test and pull-out tests. The effect of plasma treatment on functional groups of jute fibers was observed by attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR). Scanning electron microscopy (SEM) images showed the etching effect of plasma treatment on the surface. It can be concluded that plasma treatment is an effective method to improve the surface and mechanical properties of jute fabrics to be used for composite materials.

One of the main differences between low-pressure and atmospheric-pressure plasma treatments is that there is little moisture involved in the low-pressure plasma treatment, although moisture could exist at the wall of the vacuum chamber or react with the substrate after plasma treatment, while in the atmospheric-pressure plasma treatment moisture exists not only in the environment but also in any hygroscopic substrate. In order to investigate the influence of environmental moisture on the effect of atmospheric pressure plasma treatment, ultra-high-modulus polyethylene (UHMPE) fibers were treated using an atmospheric-pressure plasma jet (APPJ) with 10 l/min helium gas-flow rate, treatment nozzle temperature of 100°C and 5 W output power. The plasma treatments were carried out at three different relative humidity levels, namely 5, 59 and 100%. After the plasma treatments, the surface roughness increased while the water-contact angle decreased with increasing relative humidity. The number of oxygen containing groups increased as the environmental moisture content increased. The interfacial shear strength of the UHMPE fiber/epoxy system was significantly increased after the plasma treatments, but the moisture level in the APPJ environment did not have a significant influence on the adhesion properties. In addition, no significant difference in single fiber tensile strength was observed after the plasma treatments at all moisture levels. Therefore, it was concluded that the environmental moisture did not significantly influence the effect of atmospheric-pressure plasma treatment in improving interfacial bonding between the fiber and epoxy. The improvement of the interfacial shear strength for the plasma-treated samples at all moisture levels was mainly due to the increased surface roughness and increased surface oxygen and nitrogen contents due to the plasma etching and surface modification effect.

Numerous methods, including chemical etching, ultraviolet radiation, and plasma treatment, are used to functionalize the surface of metallic biomedical implants and enhance osseointegration. Among these techniques, the atmospheric pressure dielectric barrier discharge (DBD) plasma jet stands out as a promising process due to its numerous advantages, including lower operational power requirements, a cost-effective setup, and short processing times. Moreover, the plasma jet demonstrates superior flexibility in treating surfaces of components with complex geometries, such as biomedical implants. This research investigates the surface treatment process utilizing a DBD plasma jet to improve the surface wettability and decontamination of Titanium (Ti) Grade 23 for biomedical applications. An increase in the surface wettability of the plasma-treated Ti substrate is demonstrated by a reduction in the water contact angle (WCA), which is linked to the changes in the surface chemistry. The X-ray photoelectron spectroscopy (XPS) analysis reveals that the interaction of Argon plasma with the Ti surface results in the formation of oxide metallic bonds, such as TiO2 and Ti2O3, while simultaneously removing carbon bonds like CO, TiC, and other organic components. This dual action leads to an increase in surface hydrophilicity and facilitates carbon-based decontamination. Further exploration of the effects of plasma treatment is conducted via a parametric study incorporating key plasma parameters such as plasma power, treatment time, and gas flow rate. While the water contact angle is insensitive to the gas flow rate, it is affected by the plasma power and treatment time. An increase in power from 2.4 W to 6 W reduces the water contact angle, followed by an increase due to a subsequent increase in power from 6 W to 13 W. The area treated by the plasma jet expands with higher plasma power or increased flow rate. The study demonstrates that a DBD Argon plasma jet operating at 2.4 W power and a 4 slm gas flow rate can effectively modify the Ti surface with just 2 s of plasma treatment. However, the optimum wettability in terms of minimum water contact angle is achieved with a 5 s plasma treatment at an input power of 6 W and a flow rate of 8 slm. Due to the formation of a surface oxide layer and the enhanced wettability of the Ti substrate resulting from plasma treatment, it is anticipated that these modifications could enhance the adhesion of Ti implants to living tissues and promote osseointegration.

An argon plasma jet was sustained in open air and characterized for its chemical composition. The optically characterized plasma jet was used to treat industrial wastewater containing mixed textile dyes and heavy metals. Since plasma jet produces UV-radiations, the photocatalytic TiO2 was used to enhance plasma treatment efficiency especially for degradation of dyes. Mixed anatase and rutile phases of TiO2 (5.2–8.5 nm) were produced through surfactant assisted sol–gel approach. The emission spectrum confirmed the presence of excited argon, OH, excited nitrogen, excited oxygen, ozone and nitric oxide in the plasma jet. The spectral lines of excited Ar, NO, O3, OH−, N2, {mathrm{N}}_{2}^{+}, O, {mathrm{O}}_{2}^{+} and O+ species were observed at wavelength of 695–740 nm, 254.3 nm, 307.9 nm, 302–310 nm, 330–380 nm, 390–415 nm, 715.6 nm, 500–600 nm and 400–500 nm. These reactive species decompose the organic pollutants and separate the heavy metals from the water samples. The conductivity of plasma exposed water samples increased while pH and hardness decreased. The atomic absorption spectrophotometry analysis confirmed the presence of heavy metals in the samples, which were effectively removed through plasma treatment. Finally, the effect of plasma treatment on Staphylococcus aureus strains was more pronounced than Escherichia coli strains.

Over the past decades, the challenge of sustainable energy production at low cost has persisted. Hydrogen emerges as a viable alternative fuel for various applications, yet its utilization faces hurdles. This particularly concerns the sluggish kinetics of the oxygen evolution reaction (OER) at the anode, necessitating higher input energy than theoretically optimal. Apart from an active electrocatalyst, the structure of the anode coating significantly influences performance [1-2-3]. Typically, fluorinated polymer compounds serve as a binder/ionomer, enhancing ionic transport during OER [4]. However, its exorbitant price and compliance with European Union regulations banning per- and polyfluoro substances (PFAS) poses challenges. One solution is to develop binder-free anodes. In this study, we explore the effectiveness of a nitrogen plasma treatment (PT) on catalyst-coated nickel plates with varying mass loadings to achieve binder-free and efficient OER performance.As a starting point, we utilized commercial nickel-cobalt-oxide (NiCoO2, Merck group), featuring processable primary particle sizes < 150 nm. Characterization of the powder involved various techniques including X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Next, Hansen solubility parameters were recorded to select the suitable dispersant and an ink was prepared using an ethanol-water mixture. Ink stability was demonstrated through analytical centrifugation measurements analyzed by transmittograms [5]. Stable inks passing this quality gate were spray coated onto Ni metal plates with varying layer numbers of 40 (anode 40L), 80 (anode 80L), and 120 (anode 120 L), corresponding to mass loadings of 375 µg cm-2, 750 ug cm-2 and 1125 ug cm-2, respectively. Noteworthily, anode 40L exhibited incomplete catalyst coverage with visible substrate whereas anode 80L and anode 120L displayed a fully covered substrate. As these layers suffered from mechanical instability due to delamination, we added post-treatment by nitrogen plasma. All anodes were analyzed before and after plasma treatment in terms of their morphology, physico-chemical characteristics, and adhesion properties. The mechanical properties of these coatings were evaluated using an adhesion analyser, revealing enhanced adhesion strength for plasma treated samples compared to their as-prepared counterparts. Scanning electron microscopy (SEM) analysis exhibited notable morphological alterations in the plasma-treated samples as illustrated in Figure 1a-c. Two distinct morphologies were observed. In case of anode 40L with plasma treatment (40L PT), the sample displayed incomplete coverage and exhibited spherical clusters of agglomerates. In contrast, the fully coated anodes 80L PT and 120L PT showcased enhanced coverage and distinct agglomerates. Besides these morphological observations, energy dispersive X-ray (EDX) analysis and X-ray photoelectron spectroscopy (XPS) showcased a notable increase in the oxygen to metal ratio in anode 40L PT compared to anodes 80L PT and 120L PT. We attribute this to the synergistic interaction between the N2 plasma and the Ni plate substrate. This holds particularly for anode 40L PT, due to its low catalyst density and exposed Ni surface from the substrate which might have potentially induced the presence of oxygen molecules on the electrode surface. Finally, electrochemical measurements showed similar activity for the fully covered anodes 80L PT and 120L PT as shown in Figure 1d. This was expected due to very similar morphologies and surface properties evidenced by the chemical analysis. This indicates that higher mass loading does not increase the OER performance after PT. In contrast, anode 40L PT exhibited clearly superior performance with an overpotential value of 373 ± 3 mV. This can be potentially attributed to the higher abundance of oxides at the surface, which might have increased the amount of active sites in the anode.Our study highlights the potential of binder-free anodes for enhancing the efficiency of the OER in hydrogen production. By employing commercial NiCoO2 powder as an electrocatalyst, coated on nickel substrates and finally utilizing a post-nitrogen plasma treatment, we achieved optimization of properties among the different layers, resulting in improved OER performance. These findings provide valuable insights into advancing the development of efficient and sustainable energy production technologies, thereby facilitating progress towards binder-free innovations in the field of electrocatalysis.

The application of plasma technology in agriculture has emerged as a promising approach to enhance plant health and manage microbial interactions, offering potential solutions for sustainable crop production and disease control. This study contributes to this field by exploring the effects of plasma treatments on plant physiology and microbial dynamics, with a focus on their potential to improve agricultural outcomes. This investigation aims to systematically determine optimal plasma seed treatment parameters for enhancing plant vigor and promoting beneficial microbial associations while minimizing pathogenic interactions in Arabidopsis thaliana. This study focuses on understanding the effects of various plasma treatments on chlorophyll content, root length, microbial growth, and microbial quantification in plants and microbes. The treatments involve the use of an atmospheric jet plasma handheld device, a globe plasma, and a glow discharge plasma chamber with air and argon. These treatments were applied for varying time durations from 10 s to 5 min. The results demonstrated that the globe plasma treatment for 1 min significantly enhanced chlorophyll a extraction and root length, outperforming the other treatments. Additionally, the study examined the impact of plasma on plant–microbe interactions to assess whether plasma treatments affect beneficial microbes. Plasma treatments showed minimal impact on most beneficial microbe activity, though species-specific sensitivities were observed, with Pseudomonas cedrina showing moderate growth inhibition, revealing no significant disruption to their activity. The microbial quantification assays indicated that the globe plasma treatment effectively reduced microbial counts, while combined treatment with plant and microbe plasma together did not yield significant changes. Additionally, the chlorophyll estimation of plasma-treated samples indicated that the globe plasma and atmospheric jet plasma treatments were effective in enhancing chlorophyll content, whereas the combined treatment with both plant and microbe plasma did not yield significant changes. These findings suggest that plasma treatments, especially the globe plasma, are effective in improving plant health and controlling microbial activity. Future research should focus on optimizing plasma conditions, exploring the influence of plasma parameters and the underlying mechanisms, and expanding the scope to include a wider range of plant species and microbial strains to maximize the benefits of plasma technology in agriculture.

This research investigates the effects of corona plasma treatment on the mechanical properties of jute/epoxy-reinforced composites, particularly within biomedical application contexts. Plant Fibre Composites (PFCs) are attractive for medical devices and scaffolds due to their environmental friendliness, renewability, cost-effectiveness, low density, and high specific strength. However, their applications are often constrained by inferior mechanical performance arising from poor bonding between the plant fibre used as the reinforcement and the synthetic resin or polymer serving as the matrix. This study addresses the challenge of improving the weak interfacial bonding between plant fibre and synthetic resin in a 2/2 twill-weave-woven jute/epoxy composite material. The surface of the jute fibre is modified for better adhesion with the epoxy resin through plasma treatment, which exposes the jute fibre to controlled plasma energy and utilises dry air (plasma only), argon (Ar) (argon gas with plasma), and nitrogen (N2) (nitrogen gas with plasma) at two different distances (25 mm and 35 mm) between the plasma nozzle and the fibre surface. In this context, "equilibrium" refers to the optimal combination of plasma power, treatment distance, and gas environment that collectively determines the degree of fibre surface modification. The results indicate that all plasma treatments improve the interlaminar shear strength in comparison to untreated samples, with treatments at 35 mm using N2 gas showing a 35.4% increase in shear strength. Conversely, plasma treatment using dry air at 25 mm yields an 18.3% increase in tensile strength and a 35.7% increase in Young's modulus. These findings highlight the importance of achieving an appropriate equilibrium among plasma intensity, treatment distance, and fibre-plasma interaction conditions to maximise the effectiveness of plasma treatment for jute/epoxy composites. This research advances sustainable innovation in biomedical materials, underscoring the potential for improved mechanical properties in environmentally friendly fibre-reinforced composites.

Cold plasma treatment for fresh-cut melon stabilization