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The grains of durum wheat (Triticum durum Desf.) and achenes of common buckwheat (Fagopyrum esculentum Moench) were tested after treatment with two sources of non-thermal atmospheric pressure plasma (DCSBD, MSDBD) with different treatment times (0, 3, 5, 10, 20, 30, and 40 s). The effect of these treatments was monitored with regard to the seed surface diagnostics (water contact angle—WCA, chemical changes by Fourier transform infrared spectroscopy—FTIR); twenty parameters associated with germination and initial seed growth were monitored. A study of the wettability confirmed a decrease in WCA values indicating an increase in surface energy and hydrophilicity depending on the type of seed, plasma source, and treatment time. Surface analysis by attenuated total reflectance FTIR (ATR-FTIR) showed no obvious changes in the chemical bonds on the surface of the plasma-treated seeds, which confirms the non-destructive effect of the plasma on the chemical composition of the seed shell. A multivariate analysis of the data showed many positive trends (not statistically significant) in germination and initial growth parameters. The repeated results for germination rate and root/shoot dry matter ratio indicate the tendency of plants to invest in underground organs. Durum wheat required longer treatment times with non-thermal plasma (10 s, 20 s) for germination and early growth, whereas buckwheat required shorter times (5 s, 10 s). The responses of durum wheat grains to the two non-thermal plasma sources used were equal. In contrast, the responses of buckwheat achenes were more favorable to MSDBD treatment than to DCSBD. [ABSTRACT FROM AUTHOR]

In this study, a high-Tg aerospace-grade epoxy composite plate was co-curing welded using a unidirectional PEEK thermoplastic carbon fibre tape to develop advanced composite joints. To account for the surface roughness and the weldability of carbon–epoxy/carbon–PEEK composites, plasma treatments were performed. The co-curing was conducted by the following steps: each treated thermoplastic tape was first placed in the mould, and followed by nine layers of dry-woven carbon fabrics. The mould was sealed using a vacuum bag, and a bi-component thermoset (RTM6) impregnated the preform. To understand the role of curing kinetics, post-curing, curing temperature, and dwell time on the quality of joints, five cure cycles were programmed. The strengths of the welded joints were investigated via the interlayer peeling test. Furthermore, cross-sections of welded zones were assessed using scanning electron microscopy in terms of the morphology of the PEEK/epoxy interphase after co-curing. The preliminary results showed that the cure cycle is an important controlling parameter for crack propagation. A noticeable distinction was evident between the samples cured first at 140 °C for 2 h and then at 180 °C for 2 h, and those cured initially at 150 °C for 2 h followed by 180 °C for 2 h. In other words, the samples subjected to the latter curing conditions exhibited consistently reproducible results with minimal errors compared to different samples. The reduced errors confirmed the reproducibility of these samples, indicating that the adhesion between CF/PEEK and CF/RTM6 tends to be more stable in this curing scenario. [ABSTRACT FROM AUTHOR]

The results of experimental studies of carbon materials, which are formed in the plasma of a direct current (DC) arc discharge initiated in open air from the asphaltenes of different origins, extracted from the natural asphaltite and from the oil of the Sredne-Ugutskoye Oilfield, are presented. The influence of the initial asphaltene composition on the composition and properties of the resulting carbon materials is analyzed. The initial asphaltenes and the samples of the carbon materials are characterized by the methods of X-ray diffraction, differential thermal analysis, X-ray fluorescence analysis, IR-Fourier spectroscopy, laser diffraction, transmission and scanning electron microscopy. The changes in the composition and structure of the asphaltenes are determined before and after their plasma treatment and the hypotheses are put forward concerning the chemical processes causing the changes in the molecular structure of the samples. As a result of plasma treatment of asphaltenes (100 A, 30 s), it was shown that graphitization occurs, as well as oxidation, and a decrease in sulfur content. Moreover, nanotubes and nano-onions have been detected using electron microscopy. Petroleum asphaltenes after plasma treatment give a less thermostable carbon material, but with a lower content of heteroatoms, and with a large amount of sulfur in the composition of sulfoxide structural fragments. This method is shown to be a promising technology for processing the petroleum feedstock enriched with heavy asphaltene components for the manufacture of carbon nanomaterials: nanotubes, nano-onions and polyhedral graphite. [ABSTRACT FROM AUTHOR]

Surface modification of polyester fabric was done using dielectric barrier discharge (DBD) with the aim of improving the adhesion properties using polyurethane (PU) polymer as an adhesive. The change in adhesion strength with respect to various plasma powers and treatment durations was examined. For analysing the adhesive bond strength of the coated fabric the T-peel off strength was investigated. After plasma treatment, an improvement in adhesion was observed compared to the untreated sample. The effect of oxygen gas on adhesion with PU adhesive was also studied. Surface wettability after plasma treatment was studied by wicking measurements. Changes in surface morphology were analysed using a scanning electron microscope (SEM) and an atomic force microscope (AFM). X-ray photoelectron spectroscopy (XPS) and ATR-FTIR were used to study the surface chemistry of plasma-treated samples. SEM, AFM, and XPS results reveal the surface roughening and incorporation of functional groups, such as C–O, C–OH, O–C=O, and COOH. No adverse effect on the mechanical strength of the plasma-modified polyester fabric was seen. [ABSTRACT FROM AUTHOR]

In this study, neem (Azadirachta indica) and pomegranate (Punica granatum) have been used as antimicrobial agents in a fixed proportion for application on linen fabric followed by plasma treatment. The treated fabric is then assessed for antimicrobial activity. It is found that, without plasma treatment, neem and pomegranate rind extract treatments provide a semi-permanent antimicrobial finish, but after plasma treatment, the durability of the finish remains closer to the permanent finish. Some significant changes in the linen fabric properties are also observed. [ABSTRACT FROM AUTHOR]

The effect of plasma treatment has been studied on thermal comfort properties of cotton and polyester fibres blended in the ratios of 0:100, 50:50 and 100:0 using four types of fabric structures, single jersey, cross tuck, cross miss and twill at two different loop lengths 0.29 cm and 0.32 cm. The findings reveal that the knitted fabrics made from 100% polyester show better thermal resistance characteristics. On the other hand, the fabric made with 100% cotton gives better air permeability and water vapour permeability behavior. The fabric knitted from 100% polyester with a cross-miss structure on a loop length of 0.32 shows an excellent thermal comfort characteristic as compared to all the other samples due to its appreciable behaviors suitable for thermal conduction. The plasma treatment has a great impact on the thermal properties, in such a way that it reduces the air permeability and water vapour permeability but increases the thermal resistance. [ABSTRACT FROM AUTHOR]

The paper presents the results of a comprehensive study of the structural-phase composition, morphology, optical, luminescent, and scintillation characteristics of thick ZnO films fabricated by magnetron sputtering. By using a hot ceramic target, extremely rapid growth (~50 µm/h) of ZnO microfilms more than 100 µm thick was performed, which is an advantage for the industrial production of scintillation detectors. The effects of post-growth treatment of the fabricated films in low-temperature plasma were studied and a significant improvement in their crystalline and optical quality was shown. As a result, the films exhibit intense near-band-edge luminescence in the near-UV region with a decay time of <1 ns. Plasma treatment also allowed to significantly weaken the visible defect luminescence excited in the near-surface regions of the films. A study of the luminescence mechanisms in the synthesized films revealed that their near-band-edge emission at room temperature is formed by phonon replicas of free exciton recombination emission. Particularly, the first phonon replica plays the main role in the case of optical excitation, while upon X-ray excitation, the second phonon replica dominates. It was also shown that the green band peaking at ~510 nm (2.43 eV) is due to surface emission centers, while longer wavelength (>550 nm) green-yellow emission originates mainly from bulk parts of the films. [ABSTRACT FROM AUTHOR]

The increasing demand for potable water is never-ending. Freshwater resources are scarce and stress is accumulating on other alternatives. Therefore, new technologies and novel optimization methods are developed for the existing processes. Membrane-based processes are among the most efficient methods for water treatment. Yet, membranes suffer from severe operational problems, namely fouling and temperature polarization. These effects can harm the membrane's permeability, permeate recovery, and lifetime. To mitigate such effects, membranes can be treated through two techniques: plasma treatment (a surface modification technique), and treatment through the use of plasmonic materials (surface and bulk modification). This article showcases plasma- and plasmonic-based treatments in the context of water desalination/purification. It aims to offer a comprehensive review of the current developments in membrane-based water treatment technologies along with suggested directions to enhance its overall efficiency through careful selection of material and system design. Moreover, basic guidelines and strategies are outlined on the different membrane modification techniques to evaluate its prerequisites. Besides, we discuss the challenges and future developments about these membrane modification methods. [ABSTRACT FROM AUTHOR]

The phase composition of coatings based on the Ti–Al–C system has been investigated on an X‑ray diffractometer and a synchrotron radiation source. The Ti–Al–C coating was deposited onto molybdenum and titanium samples by cathodic arc deposition from two single-component titanium and aluminum cathodes in a mixture of acetylene and argon. A study of the phase composition showed that the formation of the Ti2AlC and Ti2C phases depends on the heat treatment regime. The phase stability of the coating during the heating of the sample to 1500°C in vacuum was studied using synchrotron radiation. The deposited coating has an amorphous structure, which crystallizes after annealing in vacuum, forming the Ti2AlC and Ti2C phases and Ti–Al intermetallic compounds. [ABSTRACT FROM AUTHOR]

Thin films of transition metal oxides such as molybdenum oxide (MoOx) are attractive for application in silicon heterojunction solar cells for their potential to yield large short‐circuit current density. However, full control of electrical properties of thin MoOx layers must be mastered to obtain an efficient hole collector. Here, we show that the key to control the MoOx layer quality is the interface between the MoOx and the hydrogenated intrinsic amorphous silicon passivation layer underneath. By means of ab initio modelling, we demonstrate a dipole at such interface and study its minimization in terms of work function variation to enable high performance hole transport. We apply this knowledge to experimentally tailor the oxygen content in MoOx by plasma treatments (PTs). PTs act as a barrier to oxygen diffusion/reaction and result in optimal electrical properties of the MoOx hole collector. With this approach, we can thin down the MoOx thickness to 1.7 nm and demonstrate short‐circuit current density well above 40 mA/cm2 and a champion device exhibiting 23.83% conversion efficiency. [ABSTRACT FROM AUTHOR]

Polytetrafluoroethylene (PTFE), commercially known as Teflon, is a fluoropolymer with a structure containing (CF2–CF2)n. It has high resistance to acids, alkalis and corrosive chemicals. PTFE is hydrophobic in nature with a water contact angle of 140°. Being hydrophobic in nature is a knotty problem, particularly in electrical applications, as it may lead to short circuits and result in reducing the lifetime of electrical equipment. Herein we describe the surface modification of PTFE from hydrophobic to hydrophilic without altering its bulk property. The surface hydrophilicity is achieved by two different techniques, viz., polymer coating (aquivion and nafion) and plasma treatment. Several characterization techniques including FTIR, Raman, XPS, WCA and SEM were used to analyze the surface of PTFE. It was found that 5% of the polymer solution and N2 plasma treatment for 2 min can produce huge differences in the surface property, as evidenced by the reduction in water contact angle from 140° (neat Teflon) to 80° (surface-modified Teflon). The surface morphology of neat PTFE is completely changed and collapsed as evidenced by the SEM images. The FTIR, Raman and XPS analyses confirm the presence of additional hydrophilic functional groups after the polymer coating and plasma treatment. Hence, this method represents a unique approach to modifying the surface property of Teflon, while maintaining its bulk property. [ABSTRACT FROM AUTHOR]

The study delves into the impact of waste silicon-based materials on the mechanical characteristics of the resulting cement pastes. The investigation uses Portland cement CEM I 42.5R in conjunction with silicon-based waste materials sourced from the packaging industry, specifically from Recifa, a.s. Variations between the sample groups arise from differences in the concentration of silicon-based materials and the method of surface treatment. The inquiry seeks to assess the effects of two distinct levels of Si-based material incorporation, namely 10 wt. % and 20 wt. %, along with plasma treatment involving two different gases: oxygen (O2) and hydrogen (H2). The mechanical attributes under scrutiny encompass compressive and flexural strengths. The evaluation of mechanical properties is carried out on samples aged 28 days, with dimensions measuring 20 × 20 × 100 mm.

Janus monolayers of transition metal dichalcogenides (TMDCs) are promising building blocks for moiré superlattices because of their built‐in electric field and clean fabrication process. In particular, Janus TMDC monolayers can be chemically converted from conventional TMDC monolayers by atomic substitution, enabling the direct formation of lattice‐mismatched heterobilayers from TMDC bilayers. However, the moiré superlattices of Janus heterobilayers have not been studied experimentally. Herein, this work reports the fabrication and characterization of semiconductor moiré superlattices in chemically tailored Janus heterobilayers. The MoSSe/MoSe2 (or WSSe/WSe2) Janus heterobilayers are prepared by replacing the top layer Se atoms with S atoms in MoSe2 (or WSe2) bilayer using H2 plasma treatment. Scanning transmission electron microscopy reveals that an average moiré period of about 14 nm formed due to lattice mismatch resulting from the chalcogen substitutions. The cryogenic photoluminescence spectra show sharp, near‐infrared emissions, which are attributed to excitons trapped by moiré potentials based on comparison with theoretical calculations. The Janus‐based heterostructures provide a long‐period moiré system with built‐in potential even for nontwisted heterobilayers, allowing the functionalization of confined and correlated electron systems.

A new two-step method for developing a nanocomposite of polypropylene (PP) decorated with photocatalytically active TiO2 nanoparticles (nTiO2) is proposed. This method involves the low-temperature plasma functionalization of polypropylene followed by the ultrasound-assisted anchoring of nTiO2. The nanoparticles, polymeric substrate, and resultant nanocomposite were thoroughly characterized using nanoparticle tracking analysis (NTA), microscopic observations (SEM, TEM, and EDX), spectroscopic investigations (XPS and FTIR), thermogravimetric analysis (TG/DTA), and water contact angle (WCA) measurements. The photocatalytic activity of the nanocomposites was evaluated through the degradation of methyl orange. The individual TiO2 nanoparticles ranged from 2 to 6 nm in size. The oxygen plasma treatment of PP generated surface functional groups (mainly -OH and -C=O), transforming the surface from hydrophobic to hydrophilic, which facilitated the efficient deposition of nTiO2. Optimized plasma treatment and sonochemical deposition parameters resulted in an active photocatalytic nTiO2/PP system, degrading 80% of the methyl orange under UVA irradiation in 200 min. The proposed approach is considered versatile for the functionalization of polymeric materials with photoactive nanoparticles and, in a broader perspective, can be utilized for the fabrication of self-cleaning surfaces.

The chemical bath deposition (CBD) process enables the deposition of ZnO nanowires (NWs) on various substrates with customizable morphology. However, the hydrogen-rich CBD environment introduces numerous hydrogen-related defects, unintentionally doping the ZnO NWs and increasing their electrical conductivity. The oxygen-based plasma treatment can modify the nature and amount of these defects, potentially tailoring the ZnO NW properties for specific applications. This study examines the impact of the average ion energy on the formation of oxygen vacancies (VO) and hydrogen-related defects in ZnO NWs exposed to low-pressure oxygen plasma. Using X-ray photoelectron spectroscopy (XPS), 5 K cathodoluminescence (5K CL), and Raman spectroscopy, a comprehensive understanding of the effect of the oxygen ion energy on the formation of defects and defect complexes was established. A series of associative and dissociative reactions indicated that controlling plasma process parameters, particularly ion energy, is crucial. The XPS data suggested that increasing the ion energy could enhance Fermi level pinning by increasing the amount of VO and favoring the hydroxyl group adsorption, expanding the depletion region of charge carriers. The 5K CL and Raman spectroscopy further demonstrated the potential to adjust the ZnO NW physical properties by varying the oxygen ion energy, affecting various donor- and acceptor-type defect complexes. This study highlights the ability to tune the ZnO NW properties at low temperature by modifying plasma process parameters, offering new possibilities for a wide variety of nanoscale engineering devices fabricated on flexible and/or transparent substrates.

Polyvinylidene fluoride (PVDF) hollow fibers were hydrophobically modified using a simple and scalable method of plasma activation and silane grafting. The effects of plasma gas, applied voltage, activation time, silane type, and concentration were investigated according to the membrane hydrophobicity and direct contact membrane distillation (DCMD) performance. Two kinds of silane were used, including methyl trichloroalkyl silane (MTCS) and 1H,1H,2H,2H-perfluorooctane trichlorosilane silanes (PTCS). The membranes were characterized by techniques such as Fourier transform infrared (FTIR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and contact angle. The contact angle of the pristine membrane was 88°, which increased to 112°–116° after modification. Meanwhile, the pore size and porosity decreased. In DCMD, the maximum rejection reached 99.95% by the MTCS-grafted membrane, while the flux decreased by 35% and 65% for the MTCS- and PTCS-grafted membranes, respectively. Treating humic acid-contained solution, the modified membrane showed steadier water flux and higher salt rejection than the pristine membrane, and 100% flux recovery was achieved by simple water flushing. This two-step method of plasma activation and silane grafting is very simple and effective to improve the hydrophobicity and DCMD performance of PVDF hollow fibers. However, further study on improving the water flux should be carried out. HIGHLIGHTS Hydrophobic modification of PVDF fibers were carried out by plasma activation and silane grafting.; The operation conditions were optimized according to hydrophobicity and MD performance.; The contact angles increased from 88° to 112°–116° after modification.; The salt rejection increased to 99.95%, while the flux reduced for the modified membranes.; The modified membrane showed higher resistance to humic acid fouling.;

The surface properties of polymeric biomaterials play a crucial role in their biocompatibility and performance. This study explores the application of cold oxygen plasma treatment as a versatile technique for surface modification of polymeric materials with different degrees of crystallinity: crystalline high-density polyethylene (HDPE), crystalline-amorphous poly(chloro‑paraxylylene) (parylene C), and amorphous aromatic polyether-based polyurethane (PU). The investigations focus on the generation of surface functional groups and hydrophilicity, as well as nanotopography. X-ray photoelectron spectroscopy (XPS) analysis confirmed the generation of oxygen-containing functional groups, resulting in controlled wettability (water contact angle), while atomic force microscopy (AFM) showed topography modifications in the nanoscale. At the same time, it was revealed that oxygen plasma treatment did not affect the bulk properties (confirmed by TG and XRD). The effects of the same plasma treatment conditions varied significantly among the different polymers studied, depending on their crystallinity. This was discussed in terms of the preferential etching of amorphous regions in the polymeric structures. The findings emphasize the advantages of oxygen plasma treatment for tailoring the surface properties of polymeric biomaterials, highlighting its significance for biomedical applications.

AbstractThe current research utilizes a low voltage scanning electron microscopy (LV-SEM) with an electron beam along with low loading energy of lower than 2.2 KeV to minimize damage and specimen surface charging. The NovaSEM, is used as an efficient tool in the current study due to the high resolution information it can gather as images and its high magnification nanometers. Polyamide 12 (PA12), as a polymer matrix, and Cloisite 30B (C30B) nanoclay, as a filling material, were the materials tested in this study. From the results obtained, CBS was found to be a significant and valuable tool for certain complex tasks when studying and analyzing polymer/clay interfaces. CBS in conjunction with beam deceleration in a LV-SEM was used to map the C30B clay distribution on PA12 particles and within PA12-nanoclay nanocomposites manufactured from the latter’s clay distribution particles within the polymer particles’ surfaces. This SEM experimentation has demonstrated that using the clay’s air plasma design preceding the composite preparation resulted in removing the large clay assemblages. The plasma treatment has improved the interfacial adhesion and dispersion in the nanoclay/PA12 composite, resulting in similar maximum stress values which were both higher than the pure PA12. Thus, the mechanical tests exhibited performance enhancement for the resulting composites defined in the present work, and the enhancement of this method can be identified via SEM imaging.

The design of non‐noble metal bifunctional electrocatalysts with outstanding performance and remarkable stability for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is one of the most essential issues to the realization of rechargeable zinc‐air battery, and transition metal phosphides (TMPs) have emerged as robust candidates for oxygen electrocatalysts. Herein, N‐doped carbon‐coated phosphorus‐vacancies‐rich Ni2P particles (Vp‐Ni2P@NC) is proposed via simple carbonization and following Ar plasma treatment from a single nickel phosphonate metal–organic framework (MOF) without extra phosphine and nitrogen sources. The facile and rapid plasma treatment can achieve phosphorus vacancies which could modulate the electronic structure to enhance the inherent active and electrical conductivity. Meanwhile, the pyridine‐N and graphitized‐N produced during calcination also could provide more active sites and increase the electrical conductivity. The resultant Vp‐Ni2P@NC catalyst shows excellent bifunctional electrocatalytic activity (OER/ORR) based on synergistic effect of introducing P vacancies into Ni2P and N‐doped carbon. Vp‐Ni2P@NC catalyst shows more advantageous ΔE value (0.70 V) compared to Pt/C+RuO2 (0.73 V) and most reported catalysts. Additionally, the zinc‐air bbatterie (ZAB) employing Vp‐Ni2P@NC as air cathode shows excellent performance. The maximum power density of 203.48 mW cm−2, the cycling stability of more than 150 h at 10 mA cm−2. [ABSTRACT FROM AUTHOR]

In recent years, the incidence of cardiovascular disease has increased annually, and the demand for artificial blood vessels has been increasing. Due to the formation of thrombosis and stenosis after implantation, the application of many materials in the human body has been inhibited. Therefore, the choice of surface modification process is very important. In this paper, small-diameter polyurethane artificial blood vessels were prepared through electrospinning, and their surfaces were treated with plasma to improve their biological properties. The samples before and after plasma treatment were characterized by SEM, contact angle, XPS, and tensile testing; meanwhile, the cell compatibility and blood compatibility were evaluated. The results show that there are no significant changes to the fiber morphology or diameter distribution on the surface of the sample before and after plasma treatment. Plasma treatment can increase the proportion of oxygen-containing functional groups on the surface of the sample and improve its wettability, thereby increasing the infiltration ability of cells and promoting cell proliferation. Plasma treatment can reduce the risk of hemolysis, and does not cause platelet adhesion. Due to the etching effect of plasma, the mechanical properties of the samples decreased with the extension of plasma treatment time, which should be used as a basis to balance the mechanical property and biological property of artificial blood vessels. But on the whole, plasma treatment has positive significance for improving the comprehensive performance of samples. [ABSTRACT FROM AUTHOR]

To enhance the conductivity of a silver nanowire (Ag NW) network, a facile solvent welding method was developed. Soaking a Ag NW network in ethylene glycol (EG) or alcohol for less than 15 min decreased the resistance about 70%. Further combined solvent processing via a plasmonic welding approach decreased the resistance about 85%. This was achieved by simply exposing the EG-soaked Ag NW network to a low-power blue light (60 mW/cm2). Research results suggest that poly(vinylpyrrolidone) (PVP) dissolution by solvent brings nanowires into closer contact, and this reduced gap distance between nanowires enhances the plasmonic welding effect, hence further decreasing resistance. Aside from this dual combination of methods, a triple combination with Joule heating welding induced by applying a current to the Ag NW network decreased the resistance about 96%. Although conductivity was significantly enhanced, our results showed that the melting at Ag NW junctions was relatively negligible, which indicates that the enhancement in conductivity could be attributed to the removal of PVP layers. Moreover, the approaches were quite gentle so any potential damage to Ag NWs or polymer substrates by overheating (e.g., excessive Joule heating) was avoided entirely, making the approaches suitable for application in devices using heat-sensitive materials. [ABSTRACT FROM AUTHOR]

The corneal epithelial layer is continuously replaced by limbal stem cells. Reconstructing this layer in vitro using synthetic scaffolds is highly needed. Poly-lactic-co-glycolic acid (PLGA) is approved for human use due to its biocompatibility and biodegradability. However, PLGA is hydrophobic, preventing cell adherence to PLGA membranes. PLGA scaffolds were prepared by electrospinning on a custom-made target drum spinning at a rate of 1000 rpm with a flow rate of 0.5 mL/h and voltage at 20 kV, then treated with oxygen plasma at 30 mA using a vacuum coater. Scaffolds were characterized by SEM, mechanically by tensile testing, and thermally by DSC and TGA. In vitro degradation was measured by weight loss and pH drop. Wettability was assessed through water uptake and contact angles measurements. Human limbal stem cells (hLSCs) were isolated and seeded on the scaffolds. Cell attachment and cytotoxicity assay were evaluated on day 1 and 5 after cell seeding. SEM showed regular fiber morphology with diameters ranging between 150 nm and 950 nm. Tensile strength demonstrated similar average stress values for both plasma- and non-plasma-treated samples. Scaffolds also showed gradual degradability over a period of 7–8 weeks. Water contact angle and water absorption were significantly enhanced for plasma-treated scaffolds, indicating a favorable increase in their hydrophilicity. Scaffolds have also supported hLSCs growth and attachment with no signs of cytotoxicity. We have characterized a nanofiber electrospun plasma-treated PLGA scaffold to investigate the mechanical and biological properties and the ability to support the attachment and maintenance of hLSCs. [ABSTRACT FROM AUTHOR]

Plasma treatment of polypropylene (PP) is a well‐established method of improving its surface properties. However, the efficiencies of different plasma discharges are seldom compared. Herein, we discuss the differences in PP treated by three arc‐based commercial plasma jets working in dry air, Plasmatreat rotating plasma jet (PT‐RPJ), AFS PlasmaJet® (AFS‐PJ), and SurfaceTreat gliding arc jet (ST‐GA), and by the low‐temperature RF plasma slit jet (RF‐PSJ) working in argon. The AFS‐PJ has a significantly different reactive species composition dominated by nitrogen oxides. It induced higher thermal loads leading to surface damage. The other arc‐based jets (PT‐RPJ and ST‐GA) created the PP surface with higher oxygen and nitrogen concentration than the low‐temperature RF‐PSJ. It induced a higher adhesion strength measured on PP‐aluminum joints. [ABSTRACT FROM AUTHOR]

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We have developed surface acoustic wave (SAW) sensors with high sensitivity and a reversible response at room temperature (RT). The sensitive area of the sensor was prepared from vertically aligned graphene sheets, like carbon nanowalls (CNWs), which were deposited onto the quartz SAW sensor substrate. The CNWs were obtained by RF plasma-enhanced chemical vapor deposition (PECVD) at 600 °C, and their sensitivity was subsequently enhanced through hydrogen plasma treatment. The SAW sensors were tested at H2 and CH4 at RT, and they exhibited a reversible response for both gases at concentrations between 0.02% and 0.1%, with a detection limit of a few ppm. The additional hydrogen plasma treatment preserved the lamellar structure, with slight modifications to the morphology of CNW edges, as observed by scanning electron microscopy (SEM). X-ray photoelectron spectroscopy (XPS) investigations revealed the presence of new functional groups, a significant number of defects and electron transitions after the treatment. Changes in the chemical state on the CNW surface are most probably responsible for the improved gas adsorption after plasma treatment. These results identify CNWs as a promising material for designing new SAW sensors, with the possibility of using plasma treatments to enhance the detection limit below the ppm level. [ABSTRACT FROM AUTHOR]

Purpose: To compare and contrast mechanical properties of experimental alkali-resistant (AR) glass fibre-reinforced composites (FRCs) silanised with one of three functional trialkoxysilanes: 3-methacryloxypropyltrimethoxysilane (3-MPS), 8-methacryloxypropyltrimethoxysilane (8-MOS) and 3-acryloxypropyltrimethoxysilane (3-APS). The experimental AR-FRCs were silanised with or without plasma pretreatment. Materials and Methods: Continuous unidirectional AR-glass fibres (ARcoteX® 5326 2400tex, Owen Corning) were cleansed ultrasonically, treated either with or without cold plasma (Piezobrush® PZ2, Relyon Plasma, Germany), then silanised by immersion for 10 min in activated, hydrolysed silane solution containing either 3-MPS, 8-MOS or 3-APS. The fibre bundles were next air-dried (24 h), and dried in vacuum oven (80 °C, 5 kPa, 2 h), producing 6 types of silanised AR-glass fibres. Next, silanised AR-glass fibres were laminated with a resin matrix, bis-GMA:TEGDMA at 60:40 wt%, CQ at 0.7 wt%, DMAEMA at 0.7 wt% for 10 min and paired randomly in rovings of two in stainless steel moulds (2 mm × 2 mm × 25 mm) to prepare an AR-FRC beam specimen (n = 16). All specimens were light-cured from the top and bottom directions for 60 s (Elipar S10, 3 M ESPE). Half of the samples (n = 8) underwent accelerated artificial ageing by immersion in boiling water (100 °C, for 16 h). Finally, 12 experimental AR-FRC groups were produced. All specimens were subjected to the three-point bending test with the upper surface (facing curing light) towards the cross-head. After testing, fibres, silanised and non-silanised, were inspected under a scanning electron microscope (SU1510, Hitachi, Tokyo, Japan). Statistical analysis was performed with three-way ANOVA and the Tukey post hoc test at α = 0.05. Results: The flexural modulus, flexural strength, and fracture work of the materials were significantly affected by silane type (p < 0.05) and artificial ageing (p < 0.001). Plasma treatment on AR-glass fibres significantly reduces flexural modulus of FRCs (p < 0.001) and slows the plasticising effect of artificial ageing on FRCs. Conclusion: Long chain silanes impart higher flexural strength and lower flexural modulus to AR-FRCs. While artificial ageing halves flexural strength and plasticises them, plasma surface pre-treatment of AR-glass fibres before silanisation reduces the plasticising effect. [ABSTRACT FROM AUTHOR]

The distinctive cage-like structure of polyhedral oligomeric silsesquioxane (POSS) materials makes them highly effective fillers in composite membranes for separation applications. However, realizing their full potential in the application often requires specific surface functionalization with various groups. However, this requirement remains challenging owing to the limitations of wet-chemistry approaches, which frequently result in the generation of hazardous chemical by-products. In this paper, a "green" stirring plasma strategy is presented for the functionalization of octa-methyl POSS sub-micron particles into designable oxygen-containing functional groups using a low-pressure oxygen plasma from combined continuous wave and pulsed (CW+P) modes. Plasma from oxygen gas with CW mode offers highly oxygen-reactive species to continuously etch and activate the surface of the POSS. The resulting pulsed plasma assists in grafting more reactive oxygen species onto the active methyl groups of the POSS to form specific oxygen-containing functional groups including hydroxyl and carboxyl. A precise control of nearly one hydroxyl or one carboxyl group at the corner of the cage structure of the POSS is demonstrated, without damaging the core. Therefore, the plasma process discussed in this work is suggested by the authors as controllable fundamental research for the surface functionalization of sub-micron particles, promoting a more environmentally friendly pathway for the preparation of designable fillers. [ABSTRACT FROM AUTHOR]

This study's aim is a comparison of the plasma-induced effects on polymers exposed in helium and argon gaseous environments in a pulsed dielectric barrier discharge at atmospheric pressure. Cellulose-based and synthetic polymers are tested with regard to a range of parameters, such as wettability, adhesion, surface energy and polarity, the oxygen amount in their structure, and surface morphology. The surface properties are analyzed by contact angle measurements, X-ray photoelectron spectroscopy, and scanning electron microscopy images. The results point to the efficient and remarkably stable modifications of the plasma-exposed surfaces, such as their enhanced adhesion, surface energy, and oxygen incorporation. Additionally, plasma provides significant oxygen uptake in cellulose-based materials that bear already prior to treatment a high amount of oxygen in their structure. The comparison between the properties of the non-permeable, homogeneous, smooth-surface synthetic polymer and those of the loosely packed, porous, heterogeneous cellulose-based polymers points to the different rates of plasma-induced modification, whereby a progressive alteration of cellulosic surface properties over much larger ranges of exposure durations is noted. Present experimental conditions ensure mild treatments on such sensitive material, such as paper, and this is without alterations of the surface morphology and the physical degradation of the material over a large range of treatment duration. [ABSTRACT FROM AUTHOR]

Recent technological advancements led to the development of various plasma-based technologies for post-packaging modifications. The purpose of the present preclinical in vivo study was to assess the safety and efficacy of a novel chairside nonthermal gas plasma treatment for enhancing osseointegration of titanium implants. Six male mixed foxhounds underwent extraction of mandibular premolars and first molars, and the sockets healed for 42 days. Canine mandibles were randomized to receive either plasma-treated (test) or non-plasma-treated (control) dental implants. A total of 36 implants were placed in six animals, and they were sacrificed at 2 weeks (two animals), 4 weeks (two animals), and 6 weeks (two animals) after the implant surgery. When the radiographic analysis was performed, the changes in bone level were not statistically significant between the two groups at 2 weeks and 4 weeks. The difference became significant at 6 weeks (p = 0.016), indicating more bone loss from baseline to 6 weeks for the control group. The bone-to-implant contact (BIC) appeared to be higher for the test groups at all time points, and the BIC was significantly higher for the test group at 4 weeks (p = 0.046). In conclusion, this study underscored the potential of nonthermal plasma treatment in enhancing implant osseointegration. [ABSTRACT FROM AUTHOR]

In this paper, we describe the surface modification of polytetrafluoroethylene (PTFE) through the plasma treatment process. Several parameters including different active gases, RF power, distance between the plasma source and sample, and plasma duration were optimized to reduce the hydrophobic nature of PTFE. Three different active gases were used (i.e., N2, O2, and (Ar+H2)); N2 was effective to reduce the hydrophobicity of PTFE within a shorter plasma duration of 2 min. Several surface characterizations including ATR-FTIR, water contact angle, FE-SEM, and XPS were utilized to verify the neat and modified PTFE surface after plasma treatment. The plasma treatment using N2 as an active gas improved the wettability of the PTFE membrane, showing a water contact angle of 109.5° when compared with the neat PTFE (141.9°). The SEM images of plasma-treated PTFE showed greater modifications on the surface indicating non-uniform fiber alignment and torn fibers at several places. The obtained results confirm the fact that plasma treatment is an effective way to modify the PTFE surface without altering its bulk property. [ABSTRACT FROM AUTHOR]

Graphite sheet (GS) electrodes are flexible and versatile substrates for sensing electrochemical; however, their use has been limited to incorporate (bio)chemical modifiers. Herein, we demonstrated that a cold (low temperature) CO2 plasma treatment of GS electrodes provides a substantial improvement of the electrochemical activity of these electrodes due to the increased structural defects on the GS surface as revealed by Raman spectroscopy (ID/IG ratio), and scanning electron microscopy images. XPS analyses confirmed the formation of oxygenated functional groups at the GS surface after the plasma treatment that are intrinsically related to the substantial increase in the electron transfer coefficient (K0 values increased from 1.46 × 10−6 to 2.09 × 10−3 cm s−1) and with reduction of the resistance to charge transfer (from 129.8 to 0.251 kΩ). The improved electrochemical activity of CO2-GS electrodes was checked for the detection of emerging contaminant species, such as chloramphenicol (CHL), ciprofloxacin (CIP) and sulphanilamide (SUL) antibiotics, at around + 0.15, + 1.10 and + 0.85 V (versus Ag/AgCl), respectively, by square wave voltammetry. Limit of detection values in the submicromolar range were achieved for CHL (0.08 μmol L−1), CIP (0.01 μmol L−1) and SFL (0.11 μmol L−1), which enabled the sensor to be successfully applied to natural waters and urine samples (recovery values from 85 to 119%). The CO2-GS electrode is highly stable and inexpensive ($0.09 each sensor) and can be easily inserted in portable 3D printed cells for environmental on-site analyses. [ABSTRACT FROM AUTHOR]

Exposure to plasma does lead to surface erosion of textile material, we were interested in evaluating the effect of plasma treatment on the mechanical strength condition for Khadi cotton fabrics. Although surface erosion roughens and creates a larger contact area, and it is ideally suited for better dye uptake of the cotton fabrics. The surface erosion also led to the change in the content of carboxyl and carbonyl groups of the cotton fibers which was established by XPS studies. Through the study, it was inferred that the mechanical strength of Khadi cotton was affected significantly less during 1 minute of the plasma exposure. [ABSTRACT FROM AUTHOR]

The rising industrial demand for environmentally friendly and sustainable materials has shifted the attention from synthetic to natural fibers. Natural fibers provide advantages like affordability, lightweight nature, and renewability. Jute fibers' substantial production potential and cost-efficiency have propelled current research in this field. In this study, the mechanical behavior (tensile, flexural, and interlaminar shear properties) of plasma-treated jute composite laminates and the flexural behavior of jute fabric-reinforced sandwich composites were investigated. Non-woven mat fiber (MFC), jute fiber (JFC), dried jute fiber (DJFC), and plasma-treated jute fiber (TJFC) composite laminates, as well as sandwich composites consisting of jute fabric bio-based unsaturated polyester (UPE) composite as facing material and polyethylene terephthalate (PET70 and PET100) and polyvinyl chloride (PVC) as core materials were fabricated to compare their functional properties. Plasma treatment of jute composite laminate had a positive effect on some of the mechanical properties, which led to an improvement in Young's modulus (7.17 GPa) and tensile strength (53.61 MPa) of 14% and 8.5%, respectively, as well as, in flexural strength (93.71 MPa) and flexural modulus (5.20 GPa) of 24% and 35%, respectively, compared to those of JFC. In addition, the results demonstrated that the flexural properties of jute sandwich composites can be significantly enhanced by incorporating PET100 foams as core materials. [ABSTRACT FROM AUTHOR]

Fluorocarbon‐based (CF) nanofibrous membrane has been prepared by electrospinning of a source polyvinylidene fluoride and its surface was modified by CeOx nanoparticles by immersion in a water colloidal solution with CeOx nanoparticles (CeOx NPs). Two ways of the deposition of CeOx nanoparticles on the CF nanofiber membrane were used: (1) deposition of CeOx NPs on the pristine electrospun membrane and (2) the immediate deposition CeOx NPs on the plasma treated electrospun membrane. We investigated the effect of plasma treatment on the amount of CeOx NPs deposited on CF nanofiber surfaces and on the Ce3+/Ce4+ ratio in CeOx NPs deposited on CF. The amount of CeOx on nanofiber surfaces was determined by XPS (X‐ray photoelectron spectroscopy) and SEM analysis. Results showed a significant increase of CeOx NPs amount on the plasma treated CF membrane, accompanied by slight decrease of Ce3+/Ce4+ ratio in CeOx NPs adherent on plasma treated CF surface in comparison with pristine CF surface. Detailed analysis of XPS spectra – C1s, O1s, and Ce3d indicated a possibility of the chemical bonding of CeOx NPs on the plasma treated CF surface. [ABSTRACT FROM AUTHOR]

The development of energy-efficient, high-performance broadband photodetectors utilizing cost-effective amorphous metal oxide semiconductors has great potential for next-generation electronic applications. Various semiconductors are used in commercially available photodetectors to detect ultraviolet to near-infrared lights, each requiring specific semiconductors to detect different wavelengths. The utilization of a metal oxide semiconductor without an additional external photoabsorption layer for detecting a wide spectrum range from UV to NIR has attracted significant attention in the field of optoelectronics. This study utilized hydrogen plasma treatment to increase the charge carrier and generate subgap states in the IGZO film, enabling wide-spectrum detection without the need for additional external photoabsorption layers. Furthermore, a high-k dielectric was introduced as a gate dielectric to induce a high electric field on the channel, resulting in improved bias stability with low-power operation. The H2 plasma-treated IGZO phototransistors exhibited ultrahigh photoresponsivity (R ∼104–103 A W–1) and detectivity (D* ∼1014–1012 Jones) across a broad range of incident wavelengths (400–1000 nm), making them a promising candidate for next-generation optoelectronics. This study proposes a promising approach for the development of cost-effective, energy-efficient, and high-performance broadband photodetectors, which can have a significant impact on various applications such as artificial human vision systems, light detection and ranging (LiDAR), face recognition, security surveillance, optical communication, and biomedical imaging. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the effect of low-pressure plasma on the contact angle, shear bond strength (SBS), and the failure mode of zirconia ceramic. Zirconia specimens were divided into three groups according to the surface treatment methods as follows: sandblasting with aluminum oxide (ZR-C), sandblasting with aluminum oxide and oxygen plasma (ZR-CP), and argon plasma (ZR-P). The contact angle, SBS, and surface characteristics were tested after thermocycling. Data analysis was made using the Kruskal–Wallis test and one-way analysis of variance. Plasma treatment significantly reduced the contact angle (p < 0.001) with the lowest value for the Zr-P group. An increase in oxygen and a decrease in carbon was observed on the zirconia surface in both plasma groups. For the SBS, there were significant differences among the groups (p < 0.018), the Zr-CP group showing the highest bond strength. Mixed failures were the most frequent. Plasma treatment was effective in increasing the wettability, increasing the oxygen/carbon ratio without changing zirconia surface morphology. The sandblasting plus plasma with oxygen group exhibited the highest bond strength. [ABSTRACT FROM AUTHOR]

Zn-MnO 2 with rich oxygen vacancies were prepared by a synergistic strategy of element doping and plasma technology, which improved the electrochemical behaviors of MnO 2 cathode, and provided an idea for the design of the high-performance manganese oxide-based zinc ions batteies. [Display omitted] • Oxygen-rich vacancy Zn-MnO 2 was prepared by a synergistic strategy of element doping and plasma technology. • Oxygen vacancies are introduced into the Zn-MnO 2 , which improved the intrinsic conductivity and the electron transfer kinetics. • The optimal Zn/Zn-MnO 2 batteries delivered excellent specific capacity and superior retention rate performance. Easy collapse of structure and sluggish reaction kinetics restrict the practical application of MnO 2 in the field of aqueous Zn-ion batteries (ZIBs). To circumvent these obstacles, Zn2+ doping MnO 2 nanowire electrode material with rich oxygen vacancies is prepared by one-step hydrothermal method combined with plasma technology. The experimental results indicate that Zn2+ doping MnO 2 nanowire not only stabilizes the interlayer structure of MnO 2 , but also provide additional specific capacity as electrolyte ions. Meanwhile, plasma treatment technology induces the oxygen-deficient Zn-MnO 2 electrode optimizing the electronic structure to improve the electrochemical behavior of the cathode materials. Especially, the optimized Zn/Zn-MnO 2 batteries obtain outstanding specific capacity (546 mAh g−1 at 1 A g−1) and superior cycling durability (94% over 1000 continuous discharge/charge tests at 3 A g−1). Greatly, the H+ and Zn2+ reversible co-insertion/extraction energy storage system of Zn//Zn-MnO 2 -4 battery is further revealed by the various characterization analyses during the cycling test process. Further, from the perspective of reaction kinetics, plasma treatment also optimizes the diffusion control behavior of electrode materials. This research proposes a synergistic strategy of element doping and plasma technology, which has enhanced the electrochemical behaviors of MnO 2 cathode and shed light on the design of the high-performance manganese oxide-based cathodes for ZIBs. [ABSTRACT FROM AUTHOR]

Fundamental and applied research on plasma‐treated liquids for biomedical applications was boosted in the last few years, dictated by their advantages with respect to direct treatments. However, often, the lack of consistent analysis at a molecular level of these liquids, and of the processes used to produce them, have raised doubts of their usefulness in the clinic. The aim of this article is to critically discuss some basic aspects related to the use of plasma‐treated liquids in medicine, with a focus on their chemical composition. We analyze the main liquids used in the field, how they are affected by non‐thermal plasmas, and the possibility to replicate them without plasma treatment. [ABSTRACT FROM AUTHOR]

The parameters affecting the hydrophilicity and its aging effect on the polymer surface treated with atmospheric pressure plasma were investigated. A series of experimental procedures were performed according to various parameter combinations using the DoE method. The main factors having the most impact were found by quantifying the effect of each process parameter in plasma treatment. In addition, based on the results, multiple regression analysis was conducted to optimize the parameters of the experiment under conditions that maximize the hydrophilicity of the polymer surface. Finally, process capability analysis showed the superiority of optimized conditions statistically, physically, and chemically. A series of experiments and analytical procedures were characterized with the Minitab 20 program, X-ray photoelectron spectroscopy (XPS), and atomic force microscope (AFM). [ABSTRACT FROM AUTHOR]

Polystyrene (PS)/Gold (Au) is used for a wide range of applications, including composite nanofibers, catalysis, organic memory devices, and biosensing. In this work, PS films were deposited on silicon substrates via a spin coating technique followed by treatment with argon (Ar) plasma admixed with ammonia (NH3), oxygen (O2), or tetrafluoroethane (C2H2F4). X-Ray photoelectron spectroscopy (XPS) analysis revealed modified surface chemistry for Ar/O2, Ar/NH3, or Ar/C2H2F4 plasma treatment through the incorporation of oxygen, nitrogen, or fluorine groups, respectively. Size-controlled magnetron sputter deposition of Au nanoparticles (NP) onto these plasma-treated PS films was investigated via XPS and AFM techniques. The interaction of the Au NPs, as probed from the XPS and AFM measurements, is discussed by referring to changes in surface chemistry and morphology of the PS after plasma treatment. The results demonstrate the effect of surface chemistry on the interaction of Au NPs with polymer support having different surface functionalities. The XPS results show that significant oxygen surface incorporation resulted from oxygen-containing species in the plasma itself. The surface concentration of O increased from 0.4% for the pristine PS to 4.5 at%, 35.4 at%, and 45.6 at% for the Ar/C2H4F4, Ar/NH3, and Ar/O2, respectively. The water contact angle (WCA) values were noticed to decrease from 98° for the untreated PS to 95°, 37°, and 15° for Ar/C2H2F4, Ar/NH3, and Ar/O2 plasma-modified PS samples, respectively. AFM results demonstrate that surface treatment was also accompanied by surface morphology change. Small Au islands are well dispersed and cover the surface, thus forming a homogeneous, isotropic structure. The reported results are important for exploiting Au NPs use in catalysis and sensing applications.

Abstract Background In implant prosthetic dentistry, the adhesive connection of individualized ceramic crowns and prefabricated titanium bases leads to several benefits. However, the durability of the bonding could be a weak point and especially depends on sufficient surface pretreatment. Cold atmospheric-pressure plasma (CAP) is a pretreatment method that should improve the surface properties without physical damage. Thus, the purpose of this study was to investigate the influence of CAP treatment on pull-off tensile load in two-piece abutment crowns. Methods Eighty zirconia crowns and titanium bases were divided into eight groups (n = 10) according to their surface pretreatment prior to cementation with Panavia V5: no treatment (A); sandblasting (B); 10-MDP primer (C); sandblasting and primer (D); CAP (AP); sandblasting and CAP (BP); CAP and primer (CP); sandblasting, CAP and primer (DP). The specimens were thermocycled (5°/55°, 5000 cycles), and then the pull-off tensile load (TL) was measured. Statistical analyses were performed using three-way ANOVA with Tukey post-hoc and Fisher’s exact tests. Results The results showed that the TL was highest in group D (p