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This study investigates the low-temperature hydrogen plasma treatment approach for the improvement of hydrogen generation through waste aluminum (Al) reactions with water and electricity generation via proton-exchange membrane fuel cell (PEM FC). Waste Al scraps were subjected to ball milling and treated using two different low-temperature plasma regimes: Diode and magnetron-initiated plasma treatment. Hydrolysis experiments were conducted using powders with different treatments, varying molarities, and reaction temperatures to assess hydrogen generation, reaction kinetics, and activation energy. The results indicate that magnetron-initiated plasma treatment significantly enhances the hydrolysis reaction kinetics compared to untreated powders or those treated with diode-generated plasma. Analysis of chemical bonds revealed that magnetron-initiated hydrogen plasma treatment takes advantage by promoting a dual procedure: Surface cleaning and Al nanocluster deposition on top of Al powders. Moreover, it was modeled that such H2 plasma could penetrate up to 150 Å depth. Meanwhile, electricity generation tests demonstrate that only 0.2 g of treated Al powder can generate approximately 1 V for over 300 s under a constant 2.5 Ω load and 1.5 V for 2700 s with a spinning fan.

The osteoblastic differentiation of bone marrow stromal cells (bMSCs), critical to the osseointegration of titanium implants, is enhanced on titanium surfaces with biomimetic topography, and this is further enhanced when the surfaces are hydrophilic. This is a result of changing the surface free energy to change protein adsorption, improving cell attachment and differentiation, and improving bone-to-implant contact in patients. In this study, we examined different methods of plasma treatment, a well-accepted method of increasing hydrophilicity, and evaluated changes in surface properties as well as the response of bMSCs in vitro. Commercially pure Ti and titanium–aluminum–vanadium (Ti6Al4V) disks were sand-blasted and acid-etched to impart microscale and nanoscale roughness, followed by treatment with various post-processing surface modification methods, including ultraviolet light (UV), dielectric barrier discharge (DBD)-generated plasma, and plasma treatment under an argon or oxygen atmosphere. Surface wettability was based on a sessile water drop measurement of contact angle; the elemental composition was analyzed using XPS, and changes in topography were characterized using scanning electron microscopy (SEM) and confocal imaging. The cell response was evaluated using bMSCs; outcome measures included the production of osteogenic markers, paracrine signaling factors, and immunomodulatory cytokines. All plasma treatments were effective in inducing superhydrophilic surfaces. Small but significant increases in surface roughness were observed following UV, DBD and argon plasma treatment. No other modifications to surface topography were noted. However, the relative composition of Ti, O, and C varied with the treatment method. The cell response to these hydrophilic surfaces depended on the plasma treatment method used. DBD plasma treatment significantly enhanced the osteogenic response of the bMSCs. In contrast, the bMSC response to argon plasma-treated surfaces was varied, with an increase in OPG production but a decrease in OCN production. These results indicate that post-packaging methods that increased hydrophilicity as measured by contact angle did not change the surface free energy in the same way, and accordingly, cells responded differently. Wettability and surface chemistry alone are not enough to declare whether an implant has an improved osteogenic effect and do not fully explain how surface free energy affects cell response.

Non-thermal plasma (NTP) has proven to be a green method in the agricultural field for the stimulation of germination, growth, and production of nutraceutical compounds in some cases. However, the process is far from being fully understood and depends on the targeted plant species and the NTP used. In this work, we focus on the production of alfalfa sprouts from NTP-treated seeds under different voltage conditions. A flexible electrode configuration was used to produce the NTP, which can also be placed on packages for in-package treatments. The surface of the seeds was analyzed, indicating that the microstructure was strongly affected by NTP treatment. Biometric measurements evidenced the possibility of stimulating the sprout growth in some conditions by up to 50% compared to the sprouts obtained from untreated seeds. Biochemical traits for the sprouts obtained in different processing conditions were also studied, such as the concentrations of chlorophyll pigments, flavonoids and polyphenols, and antioxidant activity. Most NTP treatments led to inhibitory effects, proving the strong dependence between NTP treatment and targeted plant species.

This study involved the creation of highly porous PLA scaffolds through the porogen/leaching method, utilizing polyethylene glycol as a porogen with a 75% mass ratio. The outcome achieved a highly interconnected porous structure with a thickness of 25 μm. To activate the scaffold’s surface and improve its hydrophilicity, radiofrequency (RF) air plasma treatment was employed. Subsequently, furcellaran subjected to sulfation or carboxymethylation was deposited onto the RF plasma treated surfaces with the intention of improving bioactivity. Surface roughness and water wettability experienced enhancement following the surface modification. The incorporation of sulfate/carboxymethyl group (DS = 0.8; 0.3, respectively) is confirmed by elemental analysis and FT-IR. Successful functionalization of PLA scaffolds was validated by SEM and XPS analysis, showing changes in topography and increases in characteristic elements (N, S, Na) for sulfated (SF) and carboxymethylated (CMF). Cytocompatibility was evaluated by using mouse embryonic fibroblast cells (NIH/3T3).

This study used Bayesian Regulated Neural Networks (BRNN) with 10-fold cross-validation to accurately forecast fading effects of plasma treatment on cotton fabrics for a given set of parameters. By training six independent BRNN models, a reduction in model complexity and an enhancement in generalizability to unknown datasets were achieved. The input comprises plasma treatment parameters and color measurements of the cotton fabric before fading, while the output comprises color measurements after fading. The plasma treatment parameters included color depth, air (oxygen) concentration, water content and treatment time. Color measurements included CIE L*a*b*C*h and K/S values. Furthermore, 162 datasets derived from two-color mixed-dye cotton fabrics were utilized for training and testing. The outcomes revealed superior prediction performance of the BRNN compared to the Levenberg-Marquardt Neural Networks, with R2 values approaching 1 and 82.35% to 94.12% of the sample predictions lying within the acceptable color difference range. Through global sensitivity analysis, the impact of treatment parameters on fading effects was quantified, providing a scientific basis for parameter adjustment. This study not only elucidated the mechanism of plasma treatment-induced fading but also offers effective prediction tools for the intelligent and digital development of the fashion clothing fading domain.

Banana fibers are cost-effective, abundantly available and environmentally sustainable, but they often have some drawbacks, such as hydrophilicity and performance variations. The experimental approach is intended to be used in this work to examine the effects of cold glow discharge argon plasma modification on the surface of banana fibers. The emphasis is on examining the mechanisms that underlie the morphological and chemical changes observed in banana fibers, as well as identifying the mechanisms that enhance the fiber–matrix interface and, as a consequence, the mechanical properties of the laminates. Significant improvements were observed for epoxy matrix laminates reinforced with banana fibers when the surface of the banana fibers was modified by plasma of argon gas (Ar) gas with varying power densities of 80,120 W for 30 min, which changed the surface chemical characteristics. The FTIR and XRD investigations revealed that plasma treatment imparted active functional groups onto the surface of the banana fiber, establishing chemical interactions with the epoxy resin. As a result, banana fibers and modified BFREC composites can be used to manufacture interior panels, headliners, seatbacks, dashboards, automobile industry, and industrial applications in order to nurture self-sustaining biodegradable natural resources. [ABSTRACT FROM AUTHOR]

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

Graphene and its related materials are increasingly applied in fiber‐reinforced polymers to tailor their material properties for high performance composites. Yet, the use of graphene derivatives that underwent a plasma functionalization process is not well understood. This study uses 1.50 wt.% of unfunctionalized (rGO) or plasma‐treated reduced graphene oxide with amine‐functionalities (frGO) in an epoxy matrix to prepare unidirectional pre‐impregnated carbon fibers. The material characteristics of the graphene‐modified carbon fiber‐reinforced polymers (g‐CFRP) are compared to the neat carbon fiber‐reinforced polymer (CFRP). Both g‐CFRP configurations exhibit a higher void content than the neat CFRP. No significant difference between the CFRP and the g‐CFRPs is observed with respect to the Young's modulus, glass transition temperature, storage modulus, specific heat capacity, thermal conductivity at room temperature, and in‐plane electrical conductivity. Yet, a reduction in ultimate tensile strength of up to −13% is noted. In addition, the apparent interlaminar shear strength and transverse electrical conductivity are increased by up to +12% for the rGO‐CFRP and +52% for the frGO‐CFRP. This knowledge will support the selection of additives for fiber‐reinforced polymers for, for example, lightning strike protection in aircrafts, sensory materials, electromagnetic interference shielding or heat transfer elements. [ABSTRACT FROM AUTHOR]

Surface hydrophilicity improvement of titanium (Ti) is of great significance for the applications of the important biomaterial. In this study, efficient hydrophilicity on the Ti surface is improved by an air plasma jet generated by a micro-hollow cathode discharge (MHCD) geometry. Elementary discharge aspects of the plasma jet and surface characteristics of the Ti surface are investigated by varying dissipated power (P d). The results show that the plasma jet can operate in a pulsed mode or a continuous mode, depending on P d. The plume length increases with P d and air flow rate increasing. By optical emission spectroscopy, plasma parameters as a function of P d are investigated. After plasma treatment, water contact angel (WCA) of the Ti sample decreases to a minimum value of 15° with P d increasing. In addition, the surface topography, roughness, and content of chemical composition are investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), and x-ray photoelectron spectroscopy (XPS) with P d increasing. The results show that Ti–O bond and O–H group on the Ti surface are beneficial to the improvement of the hydrophilicity of Ti surface. [ABSTRACT FROM AUTHOR]

The extracellular matrix (ECM) serves as a complex scaffold with diverse physical dimensions and surface properties influencing NPC cell migration. Polydimethylsiloxane (PDMS), a widely used biocompatible material, is hydrophobic and undesirable for cell seeding. Thus, the establishment of a biomimetic model with varied topographies and surface properties is essential for effective NPC43 cell separation from NP460 cells. This study explored how ECM surface properties influence NP460 and NPC43 cell behaviors via plasma treatments and chemical modifications to alter the platform surface. In addition to the conventional oxygen/nitrogen (O2/N2) plasma treatment, O2 and argon plasma treatments were utilized to modify the platform surface, which increased the hydrophilicity of the PDMS platforms, resulting in enhanced cell adhesion. (3-aminopropyl)triethoxysilane and fibronectin (FN) were used to coat the PDMS platforms uniformly and selectively. The chemical coatings significantly affected cell motility and spreading, as cells exhibited faster migration, elongated cell shapes, and larger spreading areas on FN-coated surfaces. Furthermore, narrower top layer trenches with 5 µm width and a lower concentration of 10 µg/mL FN were coated selectively on the platforms to limit NP460 cell movements and enhance NPC43 cell separation efficiency. A significantly high separation efficiency of 99.4% was achieved on the two-layer scaffold platform with 20/5 µm wide ridge/trench (R/T) as the top layer and 40/10 µm wide R/T as the bottom layer, coupling with 10 µg/mL FN selectively coated on the sidewalls of the top and bottom layers. This work demonstrated an innovative application of selective FN coating to direct cell behavior, offering a new perspective to probe into the subtleties of NPC cell separation efficiency. Moreover, this cost-effective and compact microsystem sets a new benchmark for separating cancer cells. [ABSTRACT FROM AUTHOR]

Polydimethylsiloxane (PDMS) surface has been exposed to negative glow discharge plasma of a low‐pressure discharge in pure argon for a duration varying from 10 s to 2 min. Shallow atomic force microscopy indentation experiments were performed to investigate the effect of plasma treatment on PDMS surface stiffness and adhesion energy to the silicon nitride indenter surface. The results showed an important increase in Young's modulus and a slight increase of work of adhesion. X‐ray photoelectron spectroscopy investigation of plasma‐treated PDMS surface showed a decrease of atomic content of carbon accompanied by an increase of oxygen content and suggests that the stiffening of PDMS surface can be attributed to generation of new cross‐linking Si–O–Si and Si–CH2–CH2–Si bonds between PDMS molecules. [ABSTRACT FROM AUTHOR]

The pretilt angles of LC molecules can be controlled by tetrafluoromethane (CF4) plasma treatment. For conventional polyimide layers, the homogeneous alignment turns homeotropic owing to the invasion of fluoride atoms, which leads to the wettability transition from being hydrophilic to hydrophobic. The different treatment times generate variable pretilt angles such that the values of pretilt angles can be changed from 7.21ο to 79.53ο, and the polar anchoring energy can be tuned continuously. This technique can provide a reversible alignment layer that can be controlled by applying different plasmas of CF4 and O2. Moreover, a hybrid-aligned LC cell with patterned displays based on different pretilt angles, was proposed herein. [ABSTRACT FROM AUTHOR]

Stretchable transparent electrode (STE) plays a key role in numerous emerging applications as an indispensable component for future stretchable devices. The embedded STE, as a promising candidate, possesses balanced performances and facile preparation procedures. However, it still suffers from the defects of conductive materials caused by the transferring, which results in the irreversible failure of devices. In this work, a patternable silver nanowire (AgNW) STE was fabricated by a plasma-enhanced cryo-transferring (PEC-transferring) process. Owing to the plasma-induced sintering, the AgNW network obtained remarkable improvement in robustness, which ensured the intact network after transferring and thus led to superior tensile electrical properties of the STE. Furthermore, serpentine patterns were utilized to optimize the tensile electrical properties of the STE, which achieved a figure of merit of 292.8 and 150% resistance changing under 50% strain. As a practical application, a 4 × 3 array of the mutual-capacitive type stretchable touch sensors was demonstrated for future touch sensors in stretchable devices. The PEC-transferring process opened a new avenue for patternable embedded STEs and exhibited its high potential in wearable electronics and the Internet of Thing devices. [ABSTRACT FROM AUTHOR]

The preparation of adsorbate‐free graphene with well‐defined layer numbers is a current challenge in materials and surface science and required to fabricate graphene‐based nanodevices, such as used in nanoelectromechanical systems. One strategy to tailor the layer number is oxygen‐plasma treatment of few‐layer graphene/graphite flakes. However, when graphitic materials are stored in air under ambient conditions, it is almost inevitable that adsorbates deposit on their surfaces. When precisely removing individual graphene layers from graphitic flakes by oxygen‐plasma treatment, the amount and type of adsorbates strongly affect the required plasma‐treatment process and duration. To examine the removal/etching mechanism involved in removing such layers, few‐layer graphene/graphite flakes, with areas of different layer numbers, are stored in ambient air and stepwise exposed to oxygen plasma in a shielded configuration. The flakes are then successively analyzed by multifrequency atomic force microscopy together with Raman spectroscopy, focusing on etching rate, and adsorbate and defect evolution. Combined in‐plane and out‐of‐plane tip–adsorbate–substrate interaction analysis facilitates discrimination of different types of adsorbates (water, polycyclic aromatic hydrocarbons, and linear alkanes) and their formation with time. The results demonstrate the potential regarding the development of an efficient method for cleaning of graphitic surfaces and ablation of individual graphene layers. [ABSTRACT FROM AUTHOR]

Nondegradable polyolefin plastics, which account for >60 % of total plastic waste, trigger severe global concerns and thus demand effective management technologies. However, owing to the chemical inertness of non‐polar C−C backbones in the polyolefin structure, efficient upcycling of polyolefin plastics under ambient conditions remains a great challenge. This study introduces an integrated plasma–photocatalytic technology, coupling plasma treatment with solar‐driven reforming under mild conditions, for the efficient upcycling of polyolefin plastics into value‐added hydrogen and gaseous fuels. The first plasma step grafts oxygenated groups, such as −OH, O−C=O, and C=O, onto the polyolefin chains, which leads to the formation of a polar and hydrophilic polymer that facilitates the subsequent reforming in the photocatalytic step. Therefore, high hydrogen production activity with a benchmark efficiency of >100 μmol g−1 h−1 was achieved. Moreover, the integrated process also demonstrates high versatility in upcycling different polyolefin plastics including polyethylene, polypropylene and polyvinyl chloride. The findings provide a new avenue for plastic upcycling in an efficient and sustainable way. [ABSTRACT FROM AUTHOR]

Prevention of mechanical and thermal damage to the composite parts is crucial during the debonding process of adhesive joints. This work highlights the impact of thermally expanded particles (TEPs) on bulk adhesive properties and the lap shear strength of adhesively bonded GFRP joints. FTIR studies revealed insignificant chemical changes occurring among the epoxy and its blend with TEPs. The addition of TEPs has slightly influenced the glass transition temperature (Tg) of adhesive. TMA showed that TEPs lose permanent expansion above maximum expansion temperature due to burst and/or diffuse of gas through the thin shell. DIC analysis of materials revealed that CTE mismatch grows with the addition of TEPs in x and y directions. Increases in TEP content up to 15 wt.% also raised the maximum dimension change in the epoxy adhesive. DMA and TGA studies indicated no major change in storage modulus and weight loss when GFRP was heated up to 170°C. The contact angle of GFRP decreased substantially after plasma surface treatment. Plasma surface treatment provided higher bond strength at room temperature than sandblasting surface treatment and prevented fiber-tearing. Despite the incorporation of TEPs, the enhanced debonding effectiveness at 145°C was marginal (less than 5%) for the epoxy adhesive used in the study. The incorporation of TEPs generated the residual stresses inside the adhesive as confirmed by measuring the residual strength of SLJ samples, especially 10 wt.% TEPs-epoxy joints exhibited more than 20% strength drop. [ABSTRACT FROM AUTHOR]

In this work, we study the effects of treating nanostructured SnO2–SiO2 films derived by a sol-gel method with nitrogen and oxygen plasma. The structural and chemical properties of the films are closely investigated. To quantify surface site activity in the films following treatment, we employed a photocatalytic UV degradation test with brilliant green. Using X-ray photoelectron spectroscopy, it was found that treatment with oxygen plasma led to a high deviation in the stoichiometry of the SnO2 surface and even the appearance of a tin monoxide phase. These samples also exhibited a maximum photocatalytic activity. In contrast, treatment with nitrogen plasma did not lead to any noticeable changes in the material. However, increasing the power of the plasma source from 250 W to 500 W led to the appearance of an SnO fraction on the surface and a reduction in the photocatalytic activity. In general, all the types of plasma treatment tested led to amorphization in the SnO2–SiO2 samples. [ABSTRACT FROM AUTHOR]

We report silicon nanowire (SiNW) growth with a novel Cu-In bimetallic catalyst using a plasma-enhanced chemical vapor deposition (PECVD) method. We study the structure of the catalyst nanoparticles (NPs) throughout a two-step process that includes a hydrogen plasma pre-treatment at 200 °C and the SiNW growth itself in a hydrogen-silane plasma at 420 °C. We show that the H2-plasma induces a coalescence of the Cu-rich cores of as-deposited thermally evaporated NPs that does not occur when the same annealing is applied without plasma. The SiNW growth process at 420 °C induces a phase transformation of the catalyst cores to Cu7In3; while a hydrogen plasma treatment at 420 °C without silane can lead to the formation of the Cu11In9 phase. In situ transmission electron microscopy experiments show that the SiNWs synthesis with Cu-In bimetallic catalyst NPs follows an essentially vapor-solid–solid process. By adjusting the catalyst composition, we manage to obtain small-diameter SiNWs—below 10 nm—among which we observe the metastable hexagonal diamond phase of Si, which is predicted to have a direct bandgap. [ABSTRACT FROM AUTHOR]

The effect of the properties of granulated materials (ZnO catalyst, sea salt NaCl) and plant seeds during their treatment in a dielectric barrier discharge (DBD) plasma on the combustion mode and discharge power was investigated. The discharge spatial structure was investigated using optical emission spectroscopy. Electron, vibrational, and rotational temperatures of plasma averaged over the cross section of the discharge gap were determined by analyzing the intensity distribution in rotationally unresolved spectral bands (2+) N2 and (1–) N2+. A transition from the DBD filamentary mode to a combination of filamentary and surface discharges was observed when the materials being treated were present and was accompanied by increases in the power dissipated in the discharge and the vibrational temperature in the near-electrode region in the vicinity of the material. [ABSTRACT FROM AUTHOR]

Plasmonic gold (Au) and Au-based nanocatalysts have received significant attention over the past few decades due to their unique visible light (VL) photocatalytic features for a wide variety of chemical reactions in the fields of environmental protection. However, improving their VL photocatalytic activity via a rational design is prevalently regarded as a grand challenge. Herein we boosted the VL photocatalysis of the TiO2-supported Au-Cu nanocatalyst by applying O2 plasma to treat this bimetallic plasmonic nanocatalyst. We found that O2 plasma treatment led to a strong interaction between the Au and Cu species compared with conventional calcination treatment. This interaction controlled the size of plasmonic metallic nanoparticles and also contributed to the construction of AuCu-TiO2 interfacial sites by forming AuCu alloy nanoparticles, which, thus, enabled the plasmonic Au-Cu nanocatalyst to reduce the Schottky barrier height and create numbers of highly active interfacial sites. The catalyst's characterizations and density functional theory (DFT) calculations demonstrated that boosted VL photocatalytic activity over O2 plasma treated Au-Cu/TiO2 nanocatalyst arose from the favorable transfer of hot electrons and a low barrier for the reaction between CO and O with the construction of large numbers of AuCu-TiO2 interfacial sites. This work provides an efficient approach for the rational design and development of highly active plasmonic Au and Au-based nanocatalysts and deepens our understanding of their role in VL photocatalytic reactions. [ABSTRACT FROM AUTHOR]

The 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. [ABSTRACT FROM AUTHOR]

Rosin has a great influence on the bonding of Pinus massoniana wood, and surface modification is an important way to solve this problem. In this study, Pinus massoniana wood was treated by plasma, and the effects of plasma treatment on the bonding performance and surface characteristics were investigated. The results showed the following: (1) After plasma treatment, the contact angle of Pinus massoniana wood was significantly reduced and the surface energy was significantly increased from 28.42 × 10−7 to 74.75 × 10−7 J·cm−2, and the surface wettability was also greatly improved. (2) Plasma high-energy particles experience simultaneous physical and chemical effects on the surface of Pinus massoniana wood. The former formed a micro-etched roughness on the wood surface and led to the increase in surface dispersion force, while the latter increased the aggregation and activity of polar groups on the wood surface and the degradation of some wood components and rosin, resulting in the increase in surface polar force and the enhancement of wettability. (3) After plasma treatment, the reactivity of wood was enhanced, and the cross-linking degree with adhesive and the heat release were increased. The bonding strength of Pinus massoniana wood could be improved: dry bonding from 5.08 to 5.38 MPa, boiling-water bonding strength from 4.12 to 4.53 MPa, cold-water bonding strength from 3.84 to 4.51 MPa, and the bonding stability and reliability of glued specimens were also improved. [ABSTRACT FROM AUTHOR]

Al2O3 is one of the most effective dielectric surface passivation layers for silicon solar cells, but recent studies indicate that there is still room for improvement. Instead of a single layer, multilayers of only a few nanometers thickness offer the possibility to tailor material properties on a nanometer scale. In this study, the effect of various plasma treatments performed at different stages during the ALD deposition of Al2O3/SiO2 multilayers on the silicon surface passivation quality is evaluated. Significant improvements in surface passivation quality for some plasma treatments are observed, particularly for single Al2O3/SiO2 bilayers treated with a H2 plasma after SiO2 deposition. This treatment resulted in a surface recombination parameter J0 as low as 0.35 fA cm−2 on (100) surfaces of 10 Ω cm n‐type silicon, more than a factor of 5 lower than that of Al2O3 single layers without plasma treatment. Capacitance‐voltage measurements indicate that the improved surface passivation of the plasma‐treated samples results from an enhanced chemical interface passivation rather than an improved field effect. In addition, a superior temperature stability of the surface passivation quality is found for various plasma‐treated multilayers. [ABSTRACT FROM AUTHOR]

The potential advantage of plasma treated polyethylene (PEP) in mechanical properties was studied in this research. Recycled carbon fiber (CF) was the filler used for this hand layup technique. During fabrication, 4–14 wt% CF was incorporated into PEP and the results showed the impact of both filler and plasma treatment in enhancing the mechanical strength of polymer composites. Tensile results improved from 17.51 to 22.51 MPa in the polyethylene (PE) matrix. Scanning electron microscope (SEM) results showed untreated PE composites with fiber and matrix breakages as also voids reducing the compatibility of the PE/CF phases. The maximum flexural property of 25.5 MPa was observed in 10 wt% CF/PE treated with plasma. This combination was tried with different fabrication conditions in a temperature range of 180–220°C and time duration of 20–30 min. It was clearly seen that CF/PE combinations at a temperature of 180°C and time duration of 20 min had maximum tensile and flexural strength. The optimization using Taguchi method proved the significance of CF content in enhancing the mechanical properties. It also observed better tensile strength, flexural strength properties with 10 wt% CF, 180°C temperature, 20 min time from the results. Surface images of this condition showed more dispersed CF in the PE than other combinations due to optimum temperature and time duration during fabrication. [ABSTRACT FROM AUTHOR]

Natural fiber as an intriguing option for reinforcing polymeric matrices has sparked a rising interest in creating sustainable and environmentally friendly lightweight structures. Banana fiber is a derivation of the processing of the banana plant's pseudostem (Musasepientum). Agave sisalana is a rosette-forming succulent plant cultivated largely for the fibers derived from its leaves. Sisal fibers were low in compactness, widely available and ecologically benign despite issues including hydrophilicity and performance swings. The impacts of various plasma powers (80W and 120W) for 30 min on mechanical as well as surface characteristics of unidirectional banana and sisal fibers surface treated with cold glow discharge nitrogen plasma were explored in this research. As compared to an untreated banana-sisal fiber-reinforced epoxy laminate the banana-sisal fiber-reinforced epoxy composite (BSFREC) had nearly 69.91 percent higher interlaminar shear strength, 110.01 percent higher flexural strength, 36.95 percent higher larger elongation and 79.92 percent higher tensile strength characterizations. FTIR spectroscopy and XRD were used to compare the morphological aspects of cold glow discharge nitrogen plasma-treated banana/sisal fibers and pretreated banana/sisal fibers demonstrating an improvement in fiber surface structure and boosting their adhesion to matrices. After being surface-treated banana and sisal fibers might be used in industrial applications making them a highly appealing but viable resource that helps society achieve its goal of cultivating self-sustaining yet biodegradable natural resources. [ABSTRACT FROM AUTHOR]

Herein, we propose a transparent high-performance extended-gate ion-sensitive field-effect transistor (EG-ISFET) using an electrospun indium-tin-oxide (ITO) nanofiber sensing membrane with a high specific surface area. Electrospinning is a simple and effective technique for forming nanofibers. Nevertheless, one-step calcination, such as conventional thermal annealing or microwave annealing, cannot sufficiently eliminate the inherent defects of nanofibers. In this study, we efficiently removed residual polymers and internal impurities from nanofibers via a two-step calcination process involving combustion and microwave annealing. Moreover, Ar plasma treatment was performed to improve the electrical characteristics of ITO nanofibers. Conformally coated thin-film sensing membranes were prepared as a comparative group and subjected to the same calcination conditions to verify the effect of the nanofiber sensing membrane. The characteristics of the ITO nanofiber and ITO thin-film sensing membranes were evaluated using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), optical transmittance, and conductivity. Moreover, the sensor operation of the EG-ISFETs is evaluated in terms of sensitivity and non-ideal behaviors. The optimized process improves the sensor characteristics and sensing membrane quality. Therefore, the ITO nanofiber sensing membrane improves the sensitivity and stability of the EG-ISFET, suggesting its applicability as a high-performance biochemical sensor. [ABSTRACT FROM AUTHOR]

The relevance of the study is caused by the increasing consumption of petroleum products and increasing amount of oil waste, which contains asphaltenes, the heaviest components of oil. Asphaltenes are poorly biodegradable. In many countries landfill is traditionally the method of oily waste disposal, but this method of disposal is undesirable as it requires the use of new land and may ultimately be harmful to the environment. The need has therefore arisen to find a new way of disposing oil waste, with the possibility of obtaining valuable products from it that can be used in various industrial and economic activities, which will ultimately increase the depth of oil processing. The main aim of the research is to synthesize carbon graphite-like nanomaterials by plasma recycling of asphaltenes to produce a potentially useful gas mixture containing hydrogen and methane. Objects: high molecular weight fraction of asphaltenes isolated by hot acetone extraction from natural asphaltite. Methods: plasma recycling, X-ray phase analysis, scanning and transmission electron microscopy, Raman spectroscopy. Results. This paper presents the results of experimental studies on plasma recycling of asphaltenes (the main components of heavy and residual oils, most oil wastes) combined with obtaining carbon graphite-like micro- and nanostructures. In the course of plasma processing, carbon material with graphite structure is formed. Based on the data of transmission electron microscopy, three main nanoscale morphological types are identified in the synthesis products: carbon nanotubes, polyhedral graphite and onion-like structures. In this way, the work contributes to the development of decarbonization technologies in the life cycle of hydrocarbon wastes and technologies for the production of carbon nanomaterials.

Objectives: Mask usage has increased over the last few years due to the COVID-19 pandemic, resulting in a mask shortage. Furthermore, their prolonged use causes skin problems related to bacterial overgrowth. To overcome these problems, atmospheric pressure cold plasma was studied as an alternative technology for mask disinfection. Methods: Different microorganisms (Pseudomonas aeruginosa, Escherichia coli, Staphylococcus spp.), different gases (nitrogen, argon, and air), plasma power (90-300 W), and treatment times (45 seconds to 5 minutes) were tested. Results: The best atmospheric pressure cold plasma treatment was the one generated by nitrogen gas at 300 W and 1.5 minutes. Testing of breathing and filtering performance and microscopic and visual analysis after one and five plasma treatment cycles, highlighted that these treatments did not affect the morphology or functional capacity of the masks. Conclusion: Considering the above, we strongly believe that atmospheric pressure cold plasma could be an inexpensive, eco-friendly, and sustainable mask disinfection technology enabling their reusability and solving mask shortage.

Nucleation is a basic issue in film science and technology, and it plays a vital role in the field of functional devices characterized in ultra-thin and continuous thin films. In this paper, Au clusters were deposited on three different substrates (BOPP, Si (100) and carton support film) by means of magnetron sputtering with or without air plasma pretreatment. The results show that plasma treatment conducted on BOPP substrate decreased the water contact angle significantly, indicating an enhanced surface energy of BOPP substrate. The introduction of polar groups (C–O/C–N, C=O/N–C=O and O–C=O) as well as a modified topology were responsible for the improvement of hydrophilicity. Au nanoparticles prepared on untreated substrates exhibited a non-uniform topology independent of substrate type. After plasma treatment, Au nucleation densities were increased greatly, and the nucleus sizes were much smaller. Based on the thermodynamics theory of heterogeneous nucleation, by means of plasma treatment, the substrate surface energy was enhanced and the film-substrate interfacial energy was decreased simultaneously, and both of them contributed to the higher nucleation density and smaller cluster size.

Cationic surfactants are widely used in the colloidal synthesis of noble metal nanoparticles in general, and of Pd nanoparticles in particular, to stabilize them toward aggregate formation in solution and to promote shape-specific particle growth. Despite the benefits at the synthesis stage, these surfactants can be problematic once the nanoparticles are to be applied as they may both geometrically block and electronically alter surface sites that are important for surface chemical reactions. This is particularly relevant in applications like bio- and chemosensors where analyte-nanoparticle surface interactions constitute the actual sensing event. Here, H2 sensors based on Pd and its alloys are no exception since the dissociation of H2 on the particle surface is the first step toward hydride formation and thus hydrogen detection, and it has been demonstrated that the presence of surfactant molecules detrimentally affects the hydrogen sorption rate. Here, we therefore develop a scheme to remove cationic surfactants from Pd nanoparticle surfaces by means of subsequent O2 and H2 plasma treatment, whose effectiveness we verify by X-ray photoelectron spectroscopy. Furthermore, we find that the plasma treatment both alters the surface structure of the Pd nanoparticles at the atomic level and leads to surface contamination by so-called H2 plasma swift chemical sputtering of Al, Si and F species present in the plasma chamber, which in combination significantly reduce hydrogen sorption rates and increase apparent activation energies, as revealed by plasmonic hydrogen sorption kinetic measurements. Finally, we show that both these effects can be reversed by mild thermal annealing and that after the complete plasma cleaning–thermal annealing sequence hydrogen sorption rates essentially identical to the ones of neat Pd particles never exposed to cationic surfactants can be achieved. This advertises tailored plasma cleaning and mild heat treatments as an effective recipe for the removal of surfactant molecules from nanoparticle surfaces. [ABSTRACT FROM AUTHOR]

Obtaining a robust fiber/matrix interface is crucial for enhancing the mechanical performance of fiber-reinforced composites. This study addresses the issue by presenting a novel physical–chemical modification method to improve the interfacial property of an ultra-high molecular weight polyethylene (UHMWPE) fiber and epoxy resin. The UHMWPE fiber was successfully grafted with polypyrrole (PPy) for the first time after a plasma treatment in an atmosphere of mixed oxygen and nitrogen. The results demonstrated that the maximum value of the interfacial shear strength (IFSS) of the UHMWPE fiber/epoxy reached 15.75 MPa, which was significantly enhanced by 357% compared to the pristine UHMWPE fiber. Meanwhile, the tensile strength of the UHMWPE fiber was only slightly reduced by 7.3%, which was furtherly verified by the Weibull distribution analysis. The surface morphology and structure of the PPy in-situ grown UHMWPE fibers were studied using SEM, FTIR, and contact angle measurement. The results showed that the enhancement of the interfacial performance was attributed to the increased fiber surface roughness and in-situ grown groups, which improved the surface wettability between the UHMWPE fibers and epoxy resins. [ABSTRACT FROM AUTHOR]

This study focuses on modifying the surface of an AA 5052-H32 aluminum alloy using plasma treatment. Discharge power, exposure time, and working gas were adjusted as process parameters to improve the adhesion between the aluminum alloy and glass fiber-reinforced thermoplastic (GFRTP) polycarbonate composite. The surface composition and morphology of the aluminum alloy sheet were analyzed by X-ray photoelectron spectroscopy and scanning electron microscopy, and surface roughness and wettability were evaluated using a surface roughness-measuring instrument and contact angle goniometry, respectively. The bonding performance of GFRTP/aluminum alloy was also assessed. The surface of the aluminum alloy was subjected to chemical treatment prior to plasma treatment. The results revealed that nitrogen plasma treatment led to a substantial increase (25%) in bonding strength due to the synergistic effect of rough surface mechanical bonding and chemical bonding through functional groups between the aluminum alloy and GFRTP. However, the improvement in surface wettability by plasma treatment is time dependent and may gradually diminish over time due to the re-adsorption of hydrocarbon contamination from the surrounding air. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to enhance the dyeability of polyester fabrics with turmeric natural dyes through plasma and alkaline treatments. The aim is to achieve better color strength in dyed samples without significant changes in their other properties. This is done while the weight loss is kept in a range with no considerable effect on those properties. Design/methodology/approach: The surface of a poly(ethylene terephthalate) fabric was modified using oxygen plasma at a low temperature. The alkaline hydrolysis of that polyester fabric was also done through treating it with an aqueous sodium hydroxide (NaOH) solution. The untreated and treated polyester fabrics were studied for the changes of their physical characteristics such as weight loss, wetting behavior, strength loss, bending length, flexural rigidity and K/S and wash fastness. The samples were treated with plasma and sodium hydroxide and dyed with a turmeric natural dye. Findings: In comparison to the untreated sample, the plasma-treated, alkaline-treated and plasma treatment followed by alkaline hydrolysis polyester experienced 9.3%, 68.6% and 102.3% increase in its color depth as it was dyed with a turmeric natural dye, respectively. The plasma treatment was followed by alkaline hydrolysis. The improvement in the color depth could be attributed to the surface modification. Originality/value: In this paper, investigations were conducted of the separate effects of plasma treatment and alkaline hydrolysis as well as their synergistic effect on the dyeing of the polyester fabric with a natural dye obtained from turmeric. [ABSTRACT FROM AUTHOR]

Silicone rubber molds were treated with air plasma and used to prepare polyvinyl alcohol/polyvinylpyrrolidone water-soluble microneedles. The effects of plasma treatment on mold wettability, coating adhesion, micro-needle yield and mechanical properties were discussed. The results showed that plasma treatment could generate polar hydrophilic groups on the surface of the mold, improve the wettability of the mold, the adhesion of polyvinyl alcohol/polyvinylpyrrolidone coating, and elevate the yield rate of micro-needles and the overall mechanical properties. With the prolongation of plasma treatment time, the wettability of the mold, the yield rate of microneedles and the mechanical properties increased increased and then decreased. When the silicone rubber mold was treated with air plasma for 6-8 minutes, water-soluble microneedles with a complete structure, good mechanical property and easy demolding ability could be prepared. [ABSTRACT FROM AUTHOR]

Low-density polyethylene (LDPE) and polydimethylsiloxane (silicone or PDMS) were exposed to low-pressure air, oxygen (O2), and carbon tetrafluoride (CF4) plasma to modify their surfaces. Plasma power and irradiation time were varied to determine the optimal yield for the water contact angle (θ). For both polymers, the CF4 plasma treatment resulted in the fluorination of the surfaces corroborated by FT-IR and XPS analysis, while small changes in the corresponding θ could be observed. For the O2 and air plasma treatment, the θ values of LDPE were reduced from 100° to around 60°. The changes in surface free energies (SFE) were compared for pre- and post-plasma gas treatment for both polymers and their stability under different aging conditions e.g., air, vacuum, and in water were investigated. The SFE of silicone was increased with the O2 plasma treatment from 10 to 75 mN/m and remained stable in water. Whereas the SFE of LDPE was indifferent to all storing conditions and stable up to 168 h. Also, while the SFE for the CF4 plasma-treated silicone remained almost unchanged, for the LDPE it was decreased to 15 from 35 mN/m. The wettability studies under different conditions e.g., different pH, NaCl, and BSA concentrations affirmed that they can be potentially used for biomedical applications. Finally, the multiple successive gas plasma treatment of LDPE and silicone were done up to 6 times to attain the θ values in the desired range e.g., about 120° to 30° for LDPE and 120° to 13° for silicone. [ABSTRACT FROM AUTHOR]

Low-molar ratio UF resin was used in bonding veneers of five wood species. Significantly different bonding strengths were observed among the used wood species. Much higher bonding strengths were found for cherry, sapele mahogany and black walnut, which would be attributed to their natural roughness that allows formation of more mechanical interlockings. After 60s Gliding Arc Discharge (GAD) plasma treatment of wood surface, the wet bonding performance was significantly improved for most of the wood species. The SEM images of wood surface indicated that the roughening, micrometer-scale peeling or etching effects of GAD plasma treatment would be related to the improved bonding performance. XPS characterizations showed that plasma treatment resulted in remarkable increase of O/C ratio for all wood species. Detailed analysis of C1s spectra revealed that drastic oxidation induced by plasma generated high content of oxygen-containing groups, while degradation led to exposure of more oxygen-containing components like cellulose and hemicellulose. In contrast to untreated surface, stronger interactions can be formed between highly polar wood surface and UF resin. GAD plasma appeared to be an efficient tool in both physical and chemical modifications of wood surface. [ABSTRACT FROM AUTHOR]

The effect of argon (Ar) and oxygen (O2) gases as well as the treatment times on the properties of modified bamboo fibers using dielectric barrier discharge (DBD) plasma at generated power of 180 W were investigated. The plasma treatment of bamboo fibers with inert gases leads to the generation of ions and radicals on the fiber surface. Fourier transform-infrared spectroscopy (FTIR) confirmed that the functional groups of lignin and hemicellulose were reduced owing to the removal of the amorphous portion of the fibers by plasma etching. X-ray diffraction analysis (XRD) results in an increased crystallinity percentage. X-ray photoelectron spectroscopy (XPS) results showed the oxygen/carbon (O/C) atomic concentration ratio increased with increasing treatment time. The fiber weight loss percentage increased with increased treatment time. Scanning electron microscopy (SEM) images showed that partial etching of the fiber surface led to a higher surface roughness and area and that the Ar + O2 gas plasma treatment provided more surface etching than the Ar gas treatment because of the oxidation reaction of the O2 plasma. The mechanical properties of fiber-reinforced epoxy (FRE) matrix composites revealed that the F(tr)RE-Ar (30) samples showed a high tensile strength, whereas the mechanical properties of the F(tr)RE-Ar + O2 sample decreased with increased treatment time. [ABSTRACT FROM AUTHOR]

Featured Application: The practical application of plasma-treated egg whites in the production of liver pâtés is to introduce nitrite ions to the product. Nitrite is an important ingredient in the production of meat products because it improves color, taste, and safety by inhibiting lipid oxidation, for example. The use of plasma-activated egg whites in the production of liver pâtés could be of industrial importance, as it has the potential to reduce the ingredient list, production time, and cost, and thus could make liver pâtés more competitive in the market. The use of nonthermal air plasma is rapidly becoming a novel technology as an alternative source of nitrites in the meat industry. As egg white is a versatile and cost-effective ingredient commonly used to improve the texture of meat products, the effect of its addition after plasma treatment (PTEW) on the yield, pH, residual nitrite, nitrosyl hemochrome, TBARS, color, texture parameters, and aroma profile of pork liver pâtés was studied. The nitrite ion content of plasma-activated egg whites was adjusted to the positive controls containing 60 ppm (PC1) and 120 ppm (PC2) sodium nitrite by modifying the duration of their plasma treatment (PTEW1 and PTEW2, respectively). A group without the addition of nitrites was also manufactured (NC). Each treatment (NC, PC1, PC2, PTEW1, PTEW2) was analyzed on days 1, 3, 5, and 7 of storage at 4 °C. The results showed that liver pâtés containing plasma-treated egg whites had a similar nitrite and nitrosyl hemochrome content compared to samples containing the same amount of nitrite ions derived from sodium nitrite (p ≥ 0.05). In addition, 40 ppm nitrite ions, regardless of the source, was sufficient to achieve the desired reddish-pink color of the product over the entire storage period. Both nitrites from sodium nitrite and plasma-treated egg whites also significantly reduced lipid oxidation compared to the NC group (between 10% and 23% reduction on the last day), but had no significant effect on yield, pH, and texture parameters of the products. Based on the principal component analysis (PCA), the aroma profile of pâtés differed significantly between the groups with and without nitrites, with the largest differences observed on the first day (approx. 88%). Importantly, PTEW1 and PTEW2 aroma after production was similar to group PC2. The results of our study suggest that plasma-activated egg whites can be used as a potential source of nitrite in liver pâté production without adversely affecting the technological properties and shelf life of the final product. [ABSTRACT FROM AUTHOR]

The cooling performance of nanoparticle (NP)-doped radiative cooling materials depends on the dispersion of the NPs in the polymer matrix. However, it is a technical challenge to suppress agglomeration of NPs due to their high surface energy, resulting in poor dispersion of the NPs in the polymer matrix. In order to optimize the dispersion of zinc oxide (ZnO) NPs in low-density polyethylene (LDPE), NPs were treated with atmospheric pressure plasmas for 30, 60 and 90 s. The ZnO NPs were dispersed in LDPE using a xylene solution method. The dispersion of the NPs was progressively improved as the plasma-treatment time increased, likely due to the roughened and perhaps also activated NP surfaces by the plasma treatment. This made the transmittances of the films decrease in the solar-radiation band and absorptivity increased monotonically in the high-energy band as the plasma-treatment time increased, while in the mid-infrared band, the films maintained a similar high transmittance to the untreated sample. The differential scanning colorimetry analysis revealed that the crystallinities of the plasma-treated NP-doped samples were similar to those of the untreated sample. The cooling-performance tests showed that the maximum temperature reductions of the films with NP plasma-treated for 0 s, 30 s, 60 s and 90 s were 6.82, 7.90, 9.34 and 10.34 °C, respectively, corresponded to the intrinsic temperature reductions of 7.27, 8.23, 10.54, and 11.40 °C, respectively, when calculated using Cui's Model. The results of the current study show that a simple one-step atmospheric pressure plasma treatment to the ZnO NPs can indeed improve dispersion of the NPs in LDPE and lead to the greatly improved passive-cooling performance of the film. [ABSTRACT FROM AUTHOR]

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 < 0.0001). Some combinations of different treatments led to effects that were greater than the sum of the individual effects. These effects were modified by interactions. Only in combination with primer, CAP treatment had a small but positive significant effect (group CP vs. C and CP vs. AP, p < 0.0001) which however did not come close to the strong interaction effect that resulted from the combination of sandblasting and primer. Conclusion: Within the limitations of this study, CAP treatment cannot be recommended in this specific field of indication due to its unreliable influence on TL in combination with other pretreatment methods. [ABSTRACT FROM AUTHOR]

The paper presents research results of Y–Al–O system-based coatings synthesized by cathodic-arc deposition simultaneously from two electric-arc evaporators with single-component Y and Al cathodes. Three different modes of annealing are used. After the deposition process, the coatings are annealed in a vacuum furnace at 800 and at 1200°C to identify the effect from the annealing temperature on the phase composition. The formation of the YAlO3 phase occurs in all annealing modes. More complex Y3Al5O12 and Y4Al2O9 oxides appear with increasing process temperature. According to the X-ray diffraction analysis, the process temperature and deposition mode affect the phase composition of the coating, which acquires the amorphous structure. The coating structure is studied on a scanning electron microscope. After 1200°C annealing, the coating sublayer diffusion occurs in the base material. [ABSTRACT FROM AUTHOR]

The paper presents X-ray diffraction data analysis of the phase composition of heat-resistant coatings based on Ti−Al−C and Y−Al−O systems. These coatings are deposited onto molybdenum substrates using cathodic-arc deposition using two single-component titanium and aluminum cathodes in a mixture of acetylene and argon gases. It is found that the deposited coatings have the amorphous structure. After annealing, the formation of the Ti2AlC MAX phase and Ti−Al intermetallic compounds occurs in the Ti−Al−C system, whereas in the Y−Al−O system, the formation of Y2O3, YAlO3, Y4Al2O9 oxides is observed. [ABSTRACT FROM AUTHOR]

Experimental observations have shown that peptides are chemically modified under plasma treatment, which impacts the function and lifetime of a protein. This paper investigates the interactions of reactive oxygen species (ROS) produced in atmospheric plasmas and peptides. Results show that the reactions typically start with the H abstraction from the side chain of amino acids. As the reactions continue, the introduction of O atoms is the most common reaction, and the formation of double C = C bonds, detachment of carboxyl groups, and cleavage of the ring are also observed. Moreover, the degree of oxidative modification of the peptides increases with increasing doses of ROS. This study reveals the formation and breaking of chemical bonds and the generation of new reactive groups in the structure of peptides under plasma treatment, which enables us to understand the mechanisms of plasma medicine deeply. [ABSTRACT FROM AUTHOR]

Mo2C is a promising non‐precious hydrogen evolution reaction (HER) electrocatalyst. However, regulating the strong hydrogen adsorption characteristics of Mo2C and finding suitable support electrodes are essential processes before Mo2C can replace Pt to realize a sustainable hydrogen economy. Herein, the facile synthesis of heterostructured Mo2N–Mo2C nanoparticles on N‐doped carbonized wood (Mo2N–Mo2C/N‐CW) as a self‐supported electrode through carbonization and NH3 plasma treatment is demonstrated. The synergistic effects of heterostructured Mo2N–Mo2C and N‐CW with aligned microchannels provide enhanced catalytic activity, fast charge transfer kinetics, additional active site exposure, and rapid transport of the electrolyte and H2 bubbles, which improves the HER performance. Consequently, the Mo2N–Mo2C/N‐CW electrode exhibits superior HER performance with low overpotentials of only 79 and 311 mV to reach 10 and 500 mA cm−2 in an acidic solution, respectively. It also exhibits long‐term stability for 20 h in the high‐current‐density region (110 mA cm−2). The density functional theory (DFT) calculations at various sites reveal that the heterointerface of Mo2N and Mo2C promoted the catalytic activity by optimizing the adsorption/desorption of hydrogen.

The effect of atmospheric and low-pressure plasma modification on polypropylene (PP) microfibers was examined. Mechanical changes on the microfiber surfaces were observed using scanning electron microscopy (SEM). Next, wettability was measured using the packed-cell method. The fibers were applied into a cement matrix containing micro-milled recycled concrete. Test specimens were made and then the dynamic modulus of elasticity was continuously measured. After 28 days were made in the test specimens central notches to a depth of 14 mm. Finally, bending tests were performed. From the results, the fracture energy of the composite material was calculated. It was proven that low-pressure plasma modification as well as atmospheric plasma modification increases the wettability of PP fibers with water. Furthermore, it was found that samples containing plasma-modified microfibers have a higher fracture energy compared to the same samples with fibers without plasma modification. Conversely, plasma modification had no effect on the dynamic modulus of elasticity.

Abstract The preparation of adsorbate‐free graphene with well‐defined layer numbers is a current challenge in materials and surface science and required to fabricate graphene‐based nanodevices, such as used in nanoelectromechanical systems. One strategy to tailor the layer number is oxygen‐plasma treatment of few‐layer graphene/graphite flakes. However, when graphitic materials are stored in air under ambient conditions, it is almost inevitable that adsorbates deposit on their surfaces. When precisely removing individual graphene layers from graphitic flakes by oxygen‐plasma treatment, the amount and type of adsorbates strongly affect the required plasma‐treatment process and duration. To examine the removal/etching mechanism involved in removing such layers, few‐layer graphene/graphite flakes, with areas of different layer numbers, are stored in ambient air and stepwise exposed to oxygen plasma in a shielded configuration. The flakes are then successively analyzed by multifrequency atomic force microscopy together with Raman spectroscopy, focusing on etching rate, and adsorbate and defect evolution. Combined in‐plane and out‐of‐plane tip–adsorbate–substrate interaction analysis facilitates discrimination of different types of adsorbates (water, polycyclic aromatic hydrocarbons, and linear alkanes) and their formation with time. The results demonstrate the potential regarding the development of an efficient method for cleaning of graphitic surfaces and ablation of individual graphene layers.

Biodegradable Mulch Films (BMFs) offer a sustainable alternative to traditional non-degradable (Polyethylene) PE mulch films. However, their slow rate of biodegradation can lead to plastics accumulation in soil. In this study, a commercially available BMF based on poly (butylene adipate co-terephthalate) (PBAT) and poly (lactic acid) (PLA) is examined. Here the effects of gliding arc plasma treatment on the bulk and surface properties, as well as its degradation behavior in soil and compost is studied. An increase in surface oxygen containing species and hydrophilicity was observed following plasma treatment. Only a small hydrophobic recovery was noted over 30 days. No changes in the bulk polymer molecular weight or thermal properties following treatment were noted. However, a decrease in mechanical strength was observed following gliding arc plasma treatment. The onset of film fragmentation in both soil and compost occurred earlier for a plasma treated film and we attribute this to an improvement in the initial adhesion of bacteria on the surface.