ABSTRACT A nano‐TiO 2 /ZnO co‐doped micro‐arc oxidation coating (M‐Ti/Zn) was fabricated on AZ91D magnesium alloy to address rapid corrosion, poor biocompatibility, and infection risk of biodegradable implants. The M‐Ti/Zn coating exhibited the densest structure (porosity 4.866%), highest nanoparticle content (Ti 2.3%, Zn 3.1%), and superior corrosion resistance (electrochemical impedance 1.3 × 10 5 Ω·cm 2 , stable pH 7.5–8.0 over 90 days). It achieved 99.99% antibacterial rate against E. coli and S. aureus , a hemolysis rate of 4.3% (ISO10993‐4 compliant), and 110.3% osteoblast viability. Additionally, it showed the highest hardness and best wear resistance. This multifunctional coating offers excellent corrosion resistance, antibacterial property, biocompatibility, and mechanical integrity, showing great promise for biodegradable medical implants.
ABSTRACT Solid carbon is an undesirable byproduct in the plasma production of acetylene through non‐oxidative coupling of methane, as it reduces acetylene yields and complicates operation. Effective strategies to suppress carbon remain elusive owing to the complex formation mechanism. In this work, we investigate carbon morphology and growth rate by varying reactor conditions. Results show that increasing pressure enhances the carbon growth rate, which is attributed to increased C 2 H 2 concentrations. Two distinct carbon types were identified: carbon films and carbon black. Furthermore, higher pressure increased structural order while simultaneously introducing additional defects, related to changes in hydrogen content and aromatic ring configurations. This study elucidates the effect of conditions on carbon formation in methane conversion and suggests a pathway for minimizing byproducts.
ABSTRACT 2‑vinylpyridine (2VP) plasma polymers were deposited by capacitively coupled RF plasma with a pulsed vapor injector and evaluated as anion exchange membranes (AEM) for low‑temperature water electrolysis. XPS and TOF‑SIMS confirmed chemically homogeneous films and successful formation of vinyl pyridinium groups after quaternization. GISAXS, QCM and ellipso‑porometry showed that increasing plasma energy and quaternization enhances film density while limiting water uptake and swelling, suggesting improved mechanical robustness versus commercial ionomers such as Aemion. Electrochemical impedance spectroscopy revealed promising ionic conductivity, and the combination with nanometric thickness resulted in a specific resistance one order of magnitude lower than Aemion. A membrane‑electrode assembly using a 2VP plasma polymer AEM reached 1 A·cm −2 at 2 V, demonstrating a highly promising proof of concept.
ABSTRACT Mixed infections caused by fungal‐bacterial polymicrobial biofilms pose major clinical challenges, and plasma‐activated water (PAW) has potential for the treatment of infections. In this study, Candida albicans and methicillin‐resistant Staphylococcus aureus (MRSA) were used to establish fungal‐bacterial biofilms, and the inactivation effects of PAWs on the two microorganisms in biofilms were evaluated. The 30‐min PAW treatment reduced the viable C. albicans and MRSA within biofilms on silica films to below 2.00‐log 10 CFU/mL. The two consecutive 30‐min PAW treatments achieved significant reductions of approximately 3.32‐log 10 CFU/mL for C. albicans and 4.08‐log 10 CFU/mL for MRSA in biofilms on wound‐mimicking porcine skins. Therefore, owing to its non‐selective inactivation ability, PAW provides an alternative therapy for the mixed infections caused by diverse microorganisms.
ABSTRACT Cold atmospheric plasma enables the generation of reactive oxygen and nitrogen species (RONS) for biomedical use. This work develops plasma activated polysaccharide hydrogels by exposing phenol functionalized alginate, PGU, and xanthan to humid air plasma, which boosts H 2 O 2 production and triggers HRP‐mediated gelation without added peroxide. The resulting materials show pseudoplastic, self‐healing behavior, with mechanics tuned by polymer composition. Humid plasma increases incorporation of H 2 O 2 , NO 2 − , and NO 3 − , the latter being dominant. Xan Ph releases the most RONS, while PGU Ph retains less due to HRP consumption during polymerization. These findings demonstrate that humid plasma can simultaneously polymerize hydrogels and load them with RONS, offering a platform for injectable plasma activated biomaterials suited for cancer therapy, tissue engineering, and 3D bioprinting.
ABSTRACT This study proposes a dual‐dielectric plasma electrospray system for in situ generation of plasma‐activated water (PAW) mist for surface microbial inactivation. Bacteria‐ and fungi‐dominated microbial communities collected from contaminated surfaces were treated, and inactivation was evaluated by adenosine triphosphate (ATP) bioluminescence. Under optimized conditions of 13.7 kV and 11 kHz, the ATP signal decreased after 15 s and reached its minimum at 5 min, giving a maximum ATP‐based relative inactivation efficiency of 97.73%. Compared with 75% ethanol and hot‐water treatment, PAW mist showed stronger reduction of surface biological activity, especially for fungi‐dominated samples.
ABSTRACT Organosilicon coatings were deposited by atmospheric‐pressure plasma‐enhanced chemical vapour deposition (AP‐PECVD) to investigate the influence of precursor chemistry on corrosion protection. Thin films were prepared from tetraethylsilane (TES), tetraethyl orthosilicate (TEOS), and vinyltriethoxysilane (VTEOS) using an argon dielectric barrier discharge at varying precursor saturation ratios. VTEOS exhibited higher growth rates due to additional plasma‐induced free‐radical polymerisation, whereas TES and TEOS followed conventional plasma‐polymerisation. FTIR revealed Si–O–Si networks for TEOS and VTEOS, while TES formed mixed Si–O/Si–C structures. Electrochemical tests showed that ppTES and ppVTEOS coatings significantly enhance corrosion resistance, with ppTES achieving stable, low anodic currents and durable impedance over 24 h. These findings highlight the key role of precursor functionality in designing robust anti‐corrosion coatings.
ABSTRACT The safe management of antibiotic fermentation residues (AFR) is challenged by persistent bioactive antibiotics. This study employed packed‐bed dielectric barrier discharge (DBD) plasma to degrade pleuromutilin (PLM) via two strategies: (ⅰ) actual PLM residue achieved 94% removal in 40 min with reduced antibacterial activity; (ⅱ) γ‐Al 2 O 3 model system attained 98.90% removal in 10 min at 19 kV. Radical quenching confirmed reactive oxygen species ( 1 O 2 , O 2 − ) dominated degradation. LC‐MS/DFT analyses revealed plasma preferentially attacks electron‐rich PLM sites, forming low‐toxicity oxygenated products via hydroxylation and ring‐opening oxidation. Packed‐bed DBD plasma effectively reduces antimicrobial burden in hazardous AFR, offering a promising sustainable management technology.
ABSTRACT Hydrogen peroxide formation in gas–liquid discharge plasma is usually associated with the recombination of plasma‐generated hydroxyl radicals (•OH). Although alcohols are commonly regarded as •OH scavengers and are therefore expected to inhibit peroxide formation, their effects in plasma–liquid environments remain poorly understood. Here, methanol was used as a model alcohol to study alcohol‐regulated H 2 O 2 formation in an O 2 ‐containing bubble plasma system. Low methanol volume fractions markedly enhanced H 2 O 2 accumulation, whereas excessive methanol caused early saturation and reduced sustained peroxide production. H 2 O 2 formation also showed a non‐monotonic dependence on O 2 fraction, indicating the need to balance methanol content and O 2 availability. OES, electron‐density analysis, and ESR measurements revealed that alcohols regulate plasma‐induced H 2 O 2 formation by coupling plasma excitation with liquid‐phase radical chemistry, rather than simply acting as hydroxyl radical scavengers.
ABSTRACT A two‐stage foreline plasma reactor is designed and fabricated, and its feasibility for TEOS abatement in PECVD is tested. During the deposition step, the solid material from the TEOS decomposition is captured on the electrode surface as a thin film, which completely disappears after the subsequent cleaning step. OES shows that the foreline plasma is stably maintained, and QMS measurements show that the TEOS DRE exceeds 99%. The thin film formed on the electrode surface during the deposition is composed of SiO x . Analysis of the OES and QMS results shows that SiO x plasma etching occurs during the cleaning step. The results demonstrate that the reactor has a high potential as a pre‐treatment (pre‐abatement) system, thereby contributing to carbon neutrality.
ABSTRACT Airborne transmission of pathogens has emerged as a critical challenge in indoor environments, prompting the development of advanced air‐sanitization technologies. Among these, nonthermal plasma has shown promising antimicrobial effects. In this study, we evaluated the biological efficacy and energy efficiency per order (EEO) of the Grid‐like Air Plasma Sanitiser (GAPS) reactor. Experiments were conducted with Escherichia coli MG1655 bioaerosols. The GAPS achieved a reduction up to in a single pass, confirming its strong bactericidal effect. The corresponding EEO was , highlighting the reactor competitive efficiency compared with conventional methods. Preliminary assays with SARS‐CoV‐2 bioaerosols were carried out too showing a reduction of , further supporting the reactor's potential for viral inactivation.
ABSTRACT Secondary aerosol formation during non‐thermal plasma (NTP) degradation of volatile organic compounds (VOCs) complicates mechanistic interpretation and compromises reactor stability. Here, an imaging nephelometer was developed for in situ, real‐time characterization of plasma‐generated secondary aerosols. Stray light suppression through optical trapping and chamber expansion enabled sub‐nanometer sensitivity, validated by agreement between measured and theoretical Rayleigh scattering phase functions of N 2 . Using toluene degradation in a dielectric barrier discharge (DBD) reactor as model system, the effects of reaction operation conditions were systematically investigated. Aerosol mode diameters (40–100 nm) decreased with increasing discharge power and residence time, but increased with higher initial toluene concentration. This diagnostic approach provides a direct evaluation of aerosol evolution and supports mitigation of plasma‐induced fouling and catalyst deactivation.
ABSTRACT We investigate how energy‐dependent surface reactions control electron heating and density amplification in capacitively coupled Ar plasmas using a two‐dimensional particle‐in‐cell simulation. The electron emission coefficients at the surface depend explicitly on the incident ion and electron energies, leading to strong nonlinear amplification of the electron density, especially for dual‐frequency waveforms. Phase‐resolved energy distribution functions and current densities show that high‐energy electrons created by ion‐induced emission at one electrode efficiently trigger electron‐induced secondary emission at the opposite electrode. The temporally asymmetric sheaths create a feedback loop that enhances ionization, thereby increasing the overall electron density without altering the basic transport. The results suggest that managing secondary‐electron emission can be effectively leveraged to tailor plasma density profiles in practical process reactors.
ABSTRACT Microwave plasma cleaning has emerged as a high‐efficiency, low‐damage, and environmentally compatible alternative to conventional wet chemical cleaning in precision manufacturing. This review examines the principles of microwave plasma generation and the ionization behavior of common working gases, including nitrogen, oxygen, argon, and hydrogen to clarify the mechanisms of contaminant removal. Reactor components such as waveguides, impedance tuners, and quartz discharge tubes are discussed for their roles in plasma stability and energy transfer. Compared with direct current and radio frequency plasma systems, microwave plasmas provide higher electron density and ionization efficiency, enabling rapid surface activation and decomposition of organic residues while reducing solvent use, wastewater generation, and pollutant emissions.
ABSTRACT Burn treatment is a rapidly expanding research area for plasma medicine. Burn wounds have distinct pathologies, associated with poor quality healing and infection, as well as displaying a high degree of crosstalk and cellular interplay. In vitro models are common and high‐throughput but create artificial conditions dissimilar to clinical burns. Ex vivo models display higher complexity and a treatment surface representative of a true wound with the potential for infection. In vivo burn models are the most faithful for clinical plasma treatment, though the choice of animal determines the skin characteristics, the burn and the healing quality. This review will discuss various models and their interactions with plasma to guide future model selection for plasma treatment optimisation and trials.
ABSTRACT The gas temperature is a key parameter in low‐temperature plasmas, strongly influencing plasma chemistry and energy balance. It is commonly determined from the second positive system (SPS) of , particularly the band at 337 nm, assuming rotational–translational equilibrium. However, trace impurities can induce (A–X) emission that overlaps with this band and distorts temperature evaluation. We analyze optical emission from an atmospheric‐pressure dielectric barrier discharge and a low‐pressure radiofrequency plasma. Small amounts of water vapor lead to formation, despite the absence of other hydrogen‐related markers in the DBD. Neglecting contributions causes significant errors in rotational temperatures. Simultaneous fitting of SPS () and emission mitigates this effect and improves consistency.
ABSTRACT Cold plasma, a non‐thermal, partially ionized gas, is emerging as a versatile tool with strong potential to improve sustainable agriculture through pre‐ and post‐harvest stages. Cold plasma‐derived reactive oxygen and nitrogen species can enhance seed germination, stimulate plant growth, bolster stress tolerance, and inactivate pathogens without causing thermal damage or degrading quality. Pre‐harvest applications include seed treatment, modulation of plant‐associated microbiomes, and enhancement of antioxidant defenses. Post‐harvest, cold plasma enables surface decontamination, shelf‐life extension, and degradation of agrochemical residues in food, water, and soil preserving sensory and nutritional attributes. Although optimization of treatment parameters, long‐term impacts, and development of cost‐effective large‐scale systems remain, integrating cold plasma with other sustainable technologies could firmly position it within future resilient food production systems.
Cold atmospheric plasma (CAP) has potential as a new cancer treatment tool due to its room temperature biocompatibility and possible cancer cell selectivity with low side effects. This review examines the current research stage of CAP therapy for Prostate Cancer (PCa) treatment with a focus on CAP device standardization and CAP therapy clinical translation. The current CAP preclinical data is explored through the lens of PCa cellular response, PCa cells selectivity, CAP treatment type and CAP combination therapies. Finally, building on the current preclinical data, this review proposes the potential clinical application methods of CAP at different PCa stages to promote CAP therapy into clinical use.
The conventional Haber–Bosch process for nitrogen fixation is energy‐intensive and associated with high greenhouse gas emissions. Plasma‐assisted catalysis represents an alternative approach for nitrogen oxidation under milder conditions. In this study, catalyst‐assisted microwave plasma was investigated using alumina‐based catalysts and alumina‐supported metal oxides (Mo, W, Co, and Ni). Microwave plasma alone predominantly produced NO, whereas the presence of catalysts promoted additional NO 2 formation, indicating the importance of plasma–catalyst interactions. Catalytic performance depended strongly on the physicochemical properties of alumina, with δ‐Al 2 O 3 exhibiting the highest activity. Mo‐ and W‐loaded catalysts further enhanced NO x formation, while Ni and Co showed weaker effects. An overall increase of up to ~30% in NO x production was achieved compared to plasma alone.
