Effect Of Plasma Treatment Research Articles

Effect of Plasma Treatment on Self-Cleaning Features of Acrylic Paint/TiO2-Coated Surfaces for Environmental Pollutant Removal

This study investigates the characterization and performance of self-cleaning TiO2 surfaces synthesized through a one-step preparation process, followed by enhancement via plasma treatment. The process involved coating aluminum foil with an acrylic paint mixture containing nanoparticles of different mass compositions and subsequent plasma treatment using a continuous plasma arc. Scanning electron microscopy revealed the morphology of the treated surfaces, showing an increase in surface area of plasma-treated materials. Energy-dispersive X-ray spectroscopy revealed changes in oxygen and titanium in acrylic paint/TiO2 surfaces as the TiO2 content increased, indicating successful TiO2 incorporation. Raman spectroscopy showed that the bulk structure of self-cleaning acrylic paints is mainly preserved after plasma treatment. Alternating current impedance spectroscopy assessed that plasma treatment reduced agglomeration and increased active sites, especially for the acrylic paint/TiO2 surfaces with 0.5 mg/cm3 TiO2. The contact angle measurements indicated that plasma treatment enhanced the superhydrophobic characteristics and potential self-cleaning abilities of produced acrylic paint/TiO2 surfaces. The efficacy of these plasma-treated surfaces in self-cleaning was evaluated by testing their performance against puddle sediment and automotive oil samples. The study demonstrated that plasma treatment positively impacted the self-cleaning ability of the acrylic paint/TiO2 surfaces, particularly those with 0.5 mg/cm3 TiO2. This enhancement was attributed to the formation of functional groups, improved water repellency, and possible increases in surface area, which collectively contribute to the sustainable self-cleaning properties of the treated surfaces.

Effect of oxygen plasma treatment on the properties of ALD hafnium oxide films

In this work, we studied the effect of processing hafnium oxide samples prepared by atomic layer deposition in a gas discharge plasma of a mixture of argon and oxygen in a ratio of 1:10. It has been shown that such treatment preserves the amorphous structure of the film and reduces the content of oxygen vacancies in the film. This is important for the use of the film in the gate dielectric of a transistor. Processing in plasma leads to a change in its properties, namely: an increase in density and refractive index, as well as a decrease in the intensity of emission bands that are associated with an oxygen vacancy. The plasma temperature and ion energy were determined from the argon emission spectra. The activation energy for the diffusion of oxygen ions in hafnium oxide films has been calculated to be 0.43 eV.

Effect of NaOH etching and oxygen plasma treatments on surface characteristics and their potential to activate micro-arc oxidized TiO2 coatings

Activation treatments such as NaOH etching or O2 plasma can play an essential role in surface conjugation of titanium with biomolecules, providing a better interaction at the bone-implant interface. However, their application on complex titanium dioxide (TiO2) surfaces is still not explored. In this contribution, bioactive and porous TiO2 coatings produced by micro-arc oxidation (MAO) were treated with NaOH etching or O2 plasma and then placed in contact with a reactive isocyanate test compound to evaluate the potential of molecule conjugation. Results suggested that O2 plasma treatment has only changed the surface chemistry of the coating through carbon contaminants removal, plasma-driven oxidation and generation of functional OH species, including reactive carboxyl groups. This chemical modification by plasma has made the surface superhydrophilic. After NaOH etching, the coating became rougher and also superhydrophilic, containing titanate structures doped with sodium and calcium on its surface and inside the inner pores. Upon reaction with butyl isocyanate, the O2 plasma-treated surfaces seem to better provide molecule conjugation, introducing characteristic conjugation bonds, and also making MAO coatings more hydrophobic due to the surface-terminated methyl chains from isocyanate. This proof-of-concept study has demonstrated the promising grafting potential given by O2 plasma on complex TiO2 surfaces.

Inactivation Efficiency of Bacillus atrophaeus Spores on Seeds of Barley, Wheat, Lupine and Rapeseed by Direct Cold Atmospheric Pressure Plasma

The objective of this study was to evaluate the antimicrobial effect of direct cold atmospheric plasma (CAPP) treatment for pre-harvest application using four different crop species: Hordeum vulgare L. (barley), Triticum aestivum L. (wheat), Brassica napus L. (rapeseed) and Lupinus angustifolius L. (lupine). The model bacterium Bacillus atrophaeus served as a proxy for spore-forming plant pathogens on the seed surface. After semi-dry inoculation of spores onto the seeds, treatment with two different plasma sources, a volume-dielectric barrier discharge and a corona discharge, and different exposure times was carried out. Subsequently, recovery of viable spores from the seeds’ surfaces was performed. Moreover, seed viability was determined based on maximum germination, as well as water contact angle as a measure for seed surface hydrophilicity. Direct CAPP treatment was efficient in reducing viable spores of B. atrophaeus with no significant differences between the plasma sources, reaching a mean inactivation of 1 log10 CFU/mL across all treatment times and crops species. Maximum germination of seeds was not negatively affected under any treatment condition. Seed hydrophilicity was increased for both plasma sources tested. Overall, this study provides valuable information on the efficiency of direct CAPP treatment of seeds with the purpose of seed hygienization with the premise of unaltered seed vitality and evaluates the potential application in comparison with previous investigated CAPP methods.

The Effect of Cold Plasma Treatment on the Storage Stability of Mushrooms (Agaricus bisporus)

Postharvest Agaricus bisporus is susceptible to browning, water loss, and microbial infection. In order to extend its shelf life, cold plasma technology was used to treat and evaluate A. bisporus. Firstly, according to the results of a single factor test and response surface analysis, the optimal conditions for cold plasma treatment were determined as a voltage of 95 kV, a frequency of 130 Hz, and a processing time of 10 min. Secondly, storage experiments were carried out using the optimized cold plasma treatment. The results showed that the cold plasma treatment in the packaging significantly reduced the total viable count in A. bisporus by approximately 16.5%, maintained a browning degree at 26.9% lower than that of the control group, and a hardness at 25.6% higher than that of the control group. In addition, the cold plasma treatment also helped to preserve the vitamin C and total protein content of A. bisporus. In conclusion, cold plasma treatment showed great potential in enhancing the postharvest quality of fresh A. bisporus.

Supramolecular structure and in vitro digestive properties of plasma-treated corn starches varying in amylose content

The effects of plasma treatment on the multi-scale structure and in vitro digestibility of maize starch with different amylose contents were systematically evaluated. The results demonstrated that all maize starches' molecular weights (MW) decreased when treated with plasma, among which the MW of waxy maize starch displayed the largest reduction. Plasma treatment led to an increase in the thickness of the semi-crystalline lamellae and double helix proportions of waxy and normal maize starches. However, high-amylose maize starch presented a less ordered structure by plasma treatment. Additionally, larger pores and channels were observed on the surface of plasma-treated waxy and normal maize starch granules. Moreover, deposits were displayed on the surface of high-amylose maize starch granules. These changes increased the in vitro digestibility and hydrolysis rate of three starches after plasma treatment. Notably, plasma treatment caused diverse alterations in the structure and functionality of maize starch varying in amylose content, leading to maize starch with better digestibility, therefore being used as an ingredient for functional foods.

Effect of plasma treatment on LMPAEK/CF tape and composites manufactured by automated tape placement (ATP)

Automated tape placement (ATP) process is widely used in aerospace for its advanced process control and multi-axis capabilities but faces issues like limited choice of materials and suboptimal tape consolidation. This study investigates air plasma treatment on ATP carbon fiber thermoplastic feedstock tape to address these challenges. The effects on low melt Polyaryletherketone/carbon fiber unidirectional tape (LMPAEK/CF UD tape) were analyzed. Treated and untreated tapes were used to fabricate composites and evaluated for physical, thermal, mechanical, and interfacial properties. Atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) analyses revealed surface roughness changes (on LMPAEK), extent of oxidation, and the presence of hydroxyl/carboxyl groups. Composites from plasma-treated tapes showed a 7.6% increase in tensile strength, 8% in tensile modulus, 18% in flexural strength, and 8.3% in flexural modulus. The interlaminar shear strength improved by 18.7%. Failure analysis showed untreated composites failed via inter-ply and fiber-matrix delamination, while treated composites experienced matrix cracking and fiber breakage. This study highlights atmospheric plasma treatment as a solution to ATP’s limitations, significantly enhancing LMPAEK/CF UD tape composites’ properties.

Physicochemical characterization and sensory enhancement of cold plasma treated black whole wheat flour

This study examined the effects of cold plasma (CP) treatment on the physicochemical properties and sensory quality of black whole wheat flour (BWWF). Various factors including nutrient composition, color, amino acids, aroma, particle size, microstructure, antioxidant activity, and water migration were analyzed before and after CP treatment. The findings revealed that CP treatment had a minimal impact on the baseline nutrient composition of BWWF, but significantly improved its free amino acid profile, enhancing its nutritional value. The treated BWWF had an improved surface color, appeared brighter and yellower, and gave off a pleasant mellow aroma, while removing unpleasant flavor. The total phenolic content of BWWF increased while the flavonoid and anthocyanin content decreased after the treatment. CP-treated BWWF underwent aggregation cross-linking in the microstructure, and the content of bound water decreased, but the stability increased. In conclusion, CP treatment had great potential to improve the physicochemical properties and sensory quality of BWWF.

Antigenicity elimination of ovalbumin by cold plasma-induced covalent binding with Gallic acid

The effect of cold plasma (CP) treatment in promoting the covalent grafting of ovalbumin (OVA) with gallic acid (GA) were investigated, along with identifying the binding sites in the OVA-GA complex and exploring its potential for reducing the antigenicity of OVA. The results showed that the GA content of 22.97 ± 1.27 mg/g in OVA-GA complex was obtained following 60 s of CP treatment. Using LC-MS/MS, four regions (T52-R59, V201-K207, I279-R285, and V281-K291) were identified, containing 12 GA binding sites in the OVA-GA complex. Additionally, a significant reduction in IgE binding capacity (70.83 ± 0.90 %) was observed, as confirmed by ELISA analysis. The masking/steric-hindrance effect on linear epitopes and the disruption of conformational epitopes of OVA as a result of GA grafting may be the key factors leading to the reduction in OVA antigenicity. This study highlights that promoting the grafting of polyphenols onto proteins using CP treatment is an effective strategy for reducing the antigenicity of protein allergens.

Effects of atmospheric pressure plasma treatment and its aging behaviors on interfacial strength of PI/PEEK composite film

AbstractSince the properties of surface roughness with time and the wettability pattern of polymer surfaces transformed by plasma remain unclear. In order to understand the mechanism of aging effect on film properties, this paper analyzes the aging of plasma‐treated PI films. The optimal treatment conditions were first explored by adjusting the plasma treatment power. Based on the effect of plasma treatment power on the surface physicochemical properties and mechanical properties of PI films. It was found that the content of oxygen‐containing functional groups on the surface of the film was highest at a plasma treatment power of 800 W, and the surface energy reached a maximum value of 67.71 mJ/m2. As the treatment power increases, the surface etching of the PI film increases significantly, as does the roughness. However, if the power is too high, it can cause excessive etching, resulting in peeling of the film surface. In addition, the mechanical properties of the films decreased with increasing plasma treatment power. Based on the effect of plasma treatment power on the surface physicochemical and mechanical properties of PI films, the best overall modification effect of PI films was determined when the treatment power was 800 W and the speed was 6 mm/s. And at 800 W, the peel strength of the PI/PEEK composite film reached a maximum value of 9.55 N/cm, which was 77.84% higher than that of the untreated composite film. However, plasma‐treated PI films can experience surface remodeling after being exposed to air for a period of time. In this paper, the wettability as well as the mechanical properties of the films are analyzed for different aging times. The results showed that after 30 days of plasma treatment, the O/C and N/C contents on the surface of the PI film decreased, and the wettability performance decreased by 19.45% compared with that of the recently treated film.

Dye wastewater treatment using nonthermal plasma-treated copper oxide nanoparticles produced through electrolysis technique

Abstract Copper oxide nanoparticles (CuO-NPs) were produced by implementing an electrolysis technique. The prepared CuO-NPs were processed with nonthermal microwave plasma to check the effect of plasma treatment on their morphology and photocatalytic response. The plasma processed and blank CuO-NPs samples were used in dye degradation and water splitting applications under simulated sunlight. The blank sample posed undefined morphology, which turned to spherical particles on plasma processing. The particle size grows slightly with processing time. The blank samples showed a crystallite size of 4.51 nm, which grew to 5.34 nm, 5.40 nm, and 5.49 nm after plasma processing for 10, 20, and 30 min, respectively. The lattice parameter UT sample was measured to be 2.4308, with turned to 3.1091, 3.2112, and 3.3099 after 10, 20, and 30 min of plasma treatment, respectively. Similarly, band gap of CuO-NPs reduced from 2.4 eV to 2.24 eV after plasma processing for 30 min. The porosity of the nanoparticles also showed a similar trend. The plasma processing of CuO-NPs for 30 min produced the best results for photocatalytic water splitting and dye degradation applications. The photocatalytic activity revealed hydrogen evolution of 38.05 mmol.g-1.h-1 and dye removal efficiency of 91%.

Effect of cold plasma treatment on the structure and emulsifying activities of phycocyanin

Effect of cold plasma treatment on the structure and emulsifying activities of phycocyanin

The effect of cold plasma treatment on the fruit quality and aroma components of winter jujubes (Ziziphus jujuba Mill. 'Dongzao').

Cold plasma (CP) is a novel environmental-friendly preservation technology that causes minimal damage to fruits. The flavor and quality of winter jujubes have decreased with the extended storage time. Currently, the research on the use of CP on winter jujubes (Ziziphus jujuba Mill. 'Dongzao') mainly focuses on the effect of the treatment on storage quality. There is limited research on the effect of CP treatment on the flavor of winter jujubes. This study used different CP (80kV) treatment durations (0, 5, and 10min) to treat winter jujubes. The appropriate treatment time was selected by observing the changes in color, respiratory intensity, soluble sugar content, total acid content, and vitamin C (VC) content of winter jujubes. Amino acid analyzer and headspace solid-phase microextraction in combination with gas chromatography coupled with mass spectrometric detection were used to analyze the effect of CP treatment on the flavor compounds of winter jujubes. The results showed that the 5-min CP treatment could significantly slow down the red coloration of winter jujube while maintaining high soluble sugar, total acid, and VC content. At the respiration peak, the respiratory intensity of the 5-min CP treatment group was 0.74 mg CO2·kg-1·h-1 lower than that of the control group (p < 0.05). CP treatment slowed down the decrease in the content of amino acids and volatile organic compounds (such as 2-methyl-4-pentenal, 2-hexenal, and 3-hexenal) in winter jujubes. This study will provide basic data for applying CP preservation technology in postharvest winter jujubes.

Functionality enhancement of pea protein isolate through cold plasma modification for 3D printing application

Pea protein isolate (PPI) is a valued sustainable protein source, but its relatively poor functional properties limit its applications. This study reports on the effects of cold argon plasma (CP) treatment of a 15 % (w/w) PPI solution on the functionality, structure, and oxidative characteristics of PPI, as well as its application in 3D-printed plant-based meat. Results indicate that hydroxyl radicals and high-energy excited-state argon atoms are the primary active substances. A decrease in free sulfhydryl content and an increase in carbonyl content were observed in treated PPI, indicating oxidative modification. Compared to the control group, the gel strength of PPI was increased by 62.5 % and the storage modulus was significantly improved after 6 min treatment, forming a more ordered and highly cross-linked 3D gel network. Additionally, CP significantly improved the water-holding capacity, oil-holding capacity, emulsifying activity, and emulsion stability of PPI. The α-helix and random coil content in PPI decreased, while the β-sheet content increased, resulting in a more ordered secondary structure after CP treatment. Compared to untreated PPI, the consistency coefficient (K) increased from 36.00 to 47.68 Pa·sn. The treated PPI exhibited higher apparent viscosity and storage modulus and demonstrated better 3D printing performance and self-supporting ability. This study demonstrates that CP can significantly enhance the functional properties of PPI, providing great potential and prospects for improving the printability of 3D printing materials and developing plant protein foods with low-allergenicity.

Cold Plasma Ameliorates Imiquimod-Induced Psoriasis-Like Skin Inflammation in Mice.

Cold plasma has shown efficacy in various dermatological applications by reduces inflammatory responses and modulating cytokine expression. Therefore, this study aimed to investigate the therapeutic effects of cold plasma on psoriasis. In psoriasis HaCaT cells with cold plasma, we confirmed the expression of inflammatory cytokines involved in psoriasis formation and MAPK pathway, cell cycle, and apoptosis-related factors. In psoriasis-like BALB/c mice model, the effects of cold plasma treatment on skin were visually assessed. The expression of psoriasis-related factors was confirmed through qPCR, Western blotting, and Immunohistochemistry. Cold plasma led to a reduction in inflammatory cytokines including IL-17A, IL-23A, IL-24, IL-1β, and TNF-α in the psoriasis cell line. It also modulated factors involved in the MAPK pathway and the cell cycle. In the psoriasis-like mice model, cold plasma resulted in improvements in skin thickness, erythema, scaling, and PASI. Additionally, decreases in inflammatory cytokines like INF-γ, IL-23, and S100a7 were observed, along with improvements in MAPK pathway activation, apoptosis, and other psoriasis-related factors. Through in vitro and in vivo studies, our research highlights the potential of cold plasma as a novel therapeutic approach for psoriasis. Furthermore, cold plasma could serve as an adjunctive treatment for skin immunological diseases.

Effect of atmospheric cold plasma treatment on the flavor of high-fat aquatic products: A case study of golden pomfret (Trachinotus ovatus, family Bramidae) oil using GC-MS, GC-IMS, and an E-nose

This study examines the effects of atmospheric cold plasma (AP) treatment on golden pomfret oil, particularly its physicochemical properties and flavor compounds. Volatile flavor compounds in the golden pomfret fish oil were investigated following AP treatment and cold storage for 30 d using gas chromatography-mass spectrometry, gas chromatography-ion mobility mass spectrometry, and an electronic nose. The relative odor activity values revealed that certain molecules, including pentane, tridecane, styrene, methyl palmitate, benzyl benzoate, 1-methyl-2-pyrrolidinone, and oleic acid, were potential markers for distinguishing between the aromas at fresh group, 30 d of storage, and 30 d of AP storage. The content of volatile compounds changed during low-temperature refrigeration. AP treatment was a protective measure against flavor changes during storage. This information can aid in exploring the formation mechanism of the characteristic odor of AP-treated golden pomfret oil and its related metabolic pathways.

Ozone therapy vs. classical treatment in musculoskeletal disorders

With aging and weight gain, the population is significantly overweight and faces additional pressure on vertebral and peripheral joints (ankles, knees, hips, shoulders), which affects muscles, tendons, ligaments, and nerves. Muscle contraction, translated by pain, sends the patient to the doctor. Lumbar and cervical spine disorders occur in 70-80% of the world's population during their lifetime. They are a major problem because they reduce the quality of life and increase the costs borne by health services and patients. There are multiple therapeutic options, both classic medication and alternative treatment, to combat pain for a longer or shorter period. Relief or suppression of pain, the dominant symptom in the manifestations of degenerative arthritic diseases, is an important goal of treatment, ultimately improving the quality of life. Patients, for various reasons, frequently seek alternative therapies, especially to surgical treatment. Finding the most comprehensive treatment is often a challenge. If we consider the benefit that a treatment (therapy) should bring to the health condition, then an individualized therapeutic plan must be chosen. A retrospective study on the effects of ozone and platelet-rich plasma (PRP) treatment compared to classic medication shows the role of ozone therapy in pain relief and the beneficial effect of this therapy, especially in combination with PRP, over a longer period.

Osseointegration of Dental Implants after Vacuum Plasma Surface Treatment In Vivo.

Previous studies have highlighted the need for post-treatment of implants due to surface aging. This study investigated the effect of vacuum plasma (VP) treatment on the osseointegration of sandblasted, large grit, acid-etched (SLA) implant surfaces. The hypothesis was that VP might enhance implant stability, measured by implant stability quotient (ISQ) and histological osseointegration through bone-to-implant contact (BIC) and bone area ratio (BA) in rabbit models. Eighteen implants were either untreated or treated with VP and installed into the femurs of six rabbits, which were sacrificed after four weeks. Histological analyses of BIC and BA, along with micro-CT analysis of bone volume and ISQ, were performed. The VP-treated group showed higher levels of BA, bone volume, and ISQ, but no statistically significant differences were observed between the control and experimental groups. Despite limitations, both groups achieved better osseointegration and regeneration, warranting further studies on plasma treatment effects over varying implantation periods.

Impact of plasma treatment of Au electrodes on response of EIS biosensors used in aquaculture pathogen detection

This study examines the effect of plasma treatment on gold electrodes used in construction of biosensors. Plasma treatment aims to improve the adhesion of bioreceptor layers, enhancing sensor performance. Gold substrates were exposed to plasma for different durations, and their reactivity was analyzed using electrochemical impedance spectroscopy (EIS), atomic force microscopy (AFM), and scanning electron microscopy (SEM). Results show that plasma treatment significantly enhances the hydrophilicity of gold surfaces, leading to better formation of bioreceptor layer. Optimal treatment duration was found to be around 60 s, beyond which improvements in impedance values diminished. Plasma-treated electrodes displayed superior bioreceptor adhesion without altering surface topography. In conclusion, plasma treatment improves biosensor performance by enhancing bioreceptor layer adhesion. Integrating this process into biosensor production can lead to more efficient and reliable pathogen detection in aquaculture, promoting healthier aquatic environments and sustainable food production.

Reliable plasmonic biosensing with atmospheric pressure dielectric barrier discharge oxygen plasma treated polydimethylsiloxane microfluidic channels

Polydimethylsiloxane (PDMS) has emerged as a popular choice of material for many microfluidic and flexible sensing devices despite its inherent hydrophobic nature. Here, we report on the use of atmospheric pressure dielectric barrier discharge (APDBD) oxygen (O2) plasma in the development of hydrophilic and protein repulsive PDMS microchannels for plasmonic sensing application. The effect of plasma treatment on the wettability, surface energy and hydrophilicity retention capacity of PDMS was determined using contact angle measurements. The PDMS sample exposed to low-power DBD O2 plasma for 6 min demonstrated lowest contact angle of 35.15˚, surface energy of 62.83 mN/m and hydrophilicity retention capacity of more than 50 days in Phosphate Buffered Saline (PBS). The treatment of PDMS with plasma induces surface hydrophilicity due to the introduction of polar functional groups as evinced by Fourier Transform Infrared (FTIR) analysis without compromising the bulk structure and optical properties of PDMS which were confirmed by X-Ray Diffraction (XRD) and Ultraviolet-visible (UV-Vis) Spectroscopic measurements. The plasma treated PDMS was used in the construction of a microfluidic Surface Plasmon Resonance (SPR) biosensor which demonstrated very low detection limits of 7.13 ng/ml, 5.91 ng/ml and 1.47 ng/ml and high sensitivities of 16.8˚/(µg/ml), 13.5˚/(µg/ml) and 16.65˚/(µg/ml) against anti-Human Immunoglobulin-G protein raised in mouse, goat and rabbit respectively. The obtained results infer that APDBD O2 plasma is a promising technique to render PDMS hydrophilic suited for reliable microfluidic based plasmonic biosensing applications.