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Atmospheric-pressure air and nitrogen plasmas generated by surface dielectric barrier discharges have been used to incorporate new functionalities at the surface of polypropylene nonwoven fabric. The main goals were to activate the polymer surfaces for subsequent immobilization of chitosan from water solution without using any crosslinking and wetting agents. The samples were analyzed by diffuse reflectance infrared Fourier transform spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy. The nitrogen plasma treatment resulted in relatively high oxygen incorporation, about 9 atomic % mainly in aliphatic C=O type bonds and about 4 at.% of nitrogen incorporation in amine and other nitrogen functionalities. Chitosan was immobilized on the fabric fibers surfaces very homogeneously in amount of 2 - 5 g m-2. The chitosan coated samples exhibited a good laundering durability and strong antimicrobial activity against Bacillus subtilis and Escherichia coli. [ABSTRACT FROM AUTHOR]

The plasma treatment of polypropylene fibres used as concrete admixtures for improving its mechanical properties is the focus of this research paper. A plasma treatment was conducted in a low-temperature plasma environment at atmospheric pressure in a DCSBD (Diffuse Coplanar Surface Barrier Discharge). The degree of hydrophilicity caused by the plasma treatment was determined by measuring the rate of penetration of water into the porous media, commonly referred to as the Washburn method. The influence of the addition of PP (polypropylene) fibres to the concrete matrix was investigated using a three point bending test which determined the flexural strength of concrete samples. Our experiments demostrate that plasma improves both the wettability of PP fibres and its adhesion to the concrete matrix. The tests of flexural strength show, that even a short plasma treatment (5 s) can have a significant impact on the mechanical properties of fibre-reinforced concrete composite. [ABSTRACT FROM AUTHOR]

In this research a new process of plasma oxidation of crystalline silicon at room temperature is studied. The plasma oxidation was carried out using Diffuse Coplanar Surface Barrier Discharge (DCSBD) operating in ambient air and oxygen at atmospheric pressure. The influence of exposition time, plasma parameters and crystallographic orientation of silicon on oxidized layers and their dielectric properties were investigated. Thickness, structure and morphology of these layers were studied by ellipsometry, infrared absorption spectroscopy and scanning electron microscopy. During the treatment time, from 1 to 30 minutes, oxidized layers were obtained with thickness from 1 to 10 nm. Their roughness depends on the crystallographic orientation of silicon surface and exposure time. Electrical parameters of the prepared layers indicate the presence of an intermediate layer between silicon substrate and the oxidized layer. [ABSTRACT FROM AUTHOR]

The surface of a polyamide-12 (PA-12) foil was modified in order to improve the adhesive properties by two types of atmospheric pressure plasma sources. The samples were characterized using contact angle measurement, adhesive properties measurement and X-ray photoelectron spectroscopy (XPS). The ageing of the plasma modification was also studied. A significant increase in wettability was observed at different treatment times. The same effect was also seen in the adhesive properties - the adhesion was increased almost 12 times for 10 s DCSBD treatment in comparison to untreated PA-12. XPS analysis confirmed chemical changes due to the plasma modification of the PA-12. It was concluded that both plasma sources improve the adhesive properties of PA-12, with DCSBD obtaining better results. [ABSTRACT FROM AUTHOR]

Diffuse Coplanar Surface Barrier Discharge (DCSBD) is a novel type of atmospheric-pressure plasma source developed for high-speed large-area surface plasma treatments. The statistical behavior of microdischarges of DCSBD generated in artificial air atmosphere was studied using time-correlated optical and electrical measurements. Changes in behavior of microdischarges are shown for various electrode gap widths and input voltage amplitudes. They are discussed in the light of correlation of the number of microdischarges and the number of unique microdischarges' paths per discharge event. The 'memory effect' was observed in the behavior of microdischarges and it manifests itself in a significant number of microdischarges reusing the path of microdischarges from previous half-period. Surprisingly this phenomenon was observed even for microdischarges of the same half-period of the discharge, where mechanisms other than charge deposition have to be involved. The phenomenon of discharge paths reuse is most pronounced for wide electrode [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) is suitable for applications in packaging and biomedicine due to its biodegradability. To improve PLA surface adhesion a plasma-chemical treatment using nonthermal plasma generated in ambient air via diffuse coplanar surface barrier discharge (DCSBD) was used. The optimal treatment time and power were investigated. Interaction between active plasma species and the polymer surface, and the resulting surface changes were studied by contact angle measurement, surface energy determination, FTIR, and XPS. The most hydrophilic surface was obtained after only 3-4 s treatment. Treatment up to 10 s did not damage the polymer but longer treatments (30 and 60 s) caused partial degradation. The plasma broke C-C/C-H bonds and formed more C-O, O-C=O and C-O-C bonds. During storage surface oxygen decreased and a negligible amount of nitrogen was adsorbed. The oxygen-containing functional groups probably sank into the PLA volume after treatment. [ABSTRACT FROM AUTHOR]

An air diffuse coplanar surface barrier discharge is used to activate the surface of polytetrafluoroethylene (PTFE) samples, which are subsequently coated with polyvinylpyrrolidone (PVP) and tannic acid (TAN) single, bi- and multilayers, respectively, using the dip-coating method. The surfaces are characterized by X-ray Photoelectron Spectroscopy (XPS), Attenuated Total Reflection - Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Atomic Force Microscopy (AFM). The XPS measurements show that with plasma treatment the F/C atomic ratio in the PTFE surface decreases, due to the diminution of the concentration of CF2 moieties, and also oxygen incorporation through formation of new C-O, C=O and O=C-O bonds can be observed. In the case of coated samples, the new bonds indicated by XPS show the bonding between the organic layer and the surface, and thus the stability of layers, while the gradual decrease of the concentration of F atoms with the number of deposited layers proves the creation of PVP/TAN bi- and multi-layers. According to the ATR-FTIR spectra, in the case of PVP/TAN multilayer hydrogen bonding develops between the PVP and TAN, which assures the stability of the multilayer. The AFM lateral friction measurements show that the macromolecular layers homogeneously coat the plasma treated PTFE surface. [ABSTRACT FROM AUTHOR]

The applications of gas plasma and plasma modified materials in the emerging fields of medicine such as dentistry, drug delivery, and tissue engineering are reviewed. Plasma sterilization of both living and nonliving objects is safe, fast and efficient; for example plasma sterilization of medical equipment quickly removes microorganisms with no damage to the tiny delicate parts of the equipment and in dentistry it offers a non-toxic, painless bacterial inactivation of tissues from a dental cavity. Devices that generate plasma inside the root canal of a tooth give better killing efficiency against bacteria without causing any harm to the surrounding tissues. Plasma modified materials fulfill the requirements for bioactivity in medicine; for example, the inclusion of antimicrobial agents (metal nano particles, antimicrobial peptides, enzymes, etc.) in plasma modified materials (polymeric, metallic, etc.) alters them to produce superior antibacterial biomedical devices with a longer active life. Thin polymer films or coating on surfaces with different plasma processes improves the adherence, controlled loading and release of drug molecules. Surface functionalization by plasma treatment stimulates cell adhesion, cell growth and the spread of tissue development. Plasma applications are already contributing significantly to the changing face of medicine and future trends are discussed in this paper. [ABSTRACT FROM AUTHOR]

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Measurements have been made of the initial stage of breakdown in a short negative point-to-plane gap in nitrogen at pressures of 50–750 Torr and at various overvoltages. The transient glow discharge regime was found to be preceded by a peaked current signal of conspicuous similarity to the Trichel pulse rise and its initial decay in an electronegative gas. [ABSTRACT FROM AUTHOR]

This paper reflects on the future of low‐temperature plasma science in relation to the manufacturing and novel uses of glass. The text summarizes the current state of the art on the major topics discussed, such as glass processing, optics and photonics, healthcare issues, building and fenestration applications. It also identifies several challenges that are driven by applications, and which are compatible with roadmaps for their respective industries. The frontiers of plasma science are discussed, for example, in relation to the use of plasmas as an active optical element in fast‐response adaptive optics systems, optical metamaterials, and the development of next‐generation nanolithography. Future demand for the successful implementation of plasma‐based technologies in the glass, optics, and photonic industries will depend on further progress in plasma science. Hence, some needs and recommendations concerning both fundamental and applied plasma research are summarized. Non‐thermal plasmas and plasma‐assisted technologies applicable to the development of novel uses for glass in very different fields such as optics and photonics, the building industry and healthcare are reviewed. Several challenges within plasma science, such as the development of plasma sources; and the characterization of plasmas; and plasma‐assisted processes are discussed, together with well‐established future roadmaps for their corresponding industries. [ABSTRACT FROM AUTHOR]

The application of gas discharge plasmas has assumed an important place in many manufacturing processes. Plasma methods contribute significantly to the economic prosperity of industrialized societies. However, plasma is mainly an enabling method and therefore its role remains often hidden. Hence the success of plasma technologies is described for different examples and commercial areas. From these examples and emerging applications, the potential of plasma technologies is discussed. Economic trends are anticipated together with research needs. The community of plasma scientists strongly believes that more exciting advances will continue to foster innovations and discoveries in the first decades of the 21st century, if research and education will be properly funded and sustained by public bodies and industrial investors. Plasma treatments and processes contribute in many areas to technological advances. Plasma methods are crucial for manufacturing processes in the aerospace and automotive industry, the treatment of optics, glass, plastics and textiles, and for the generation and distribution of electrical energy. In general, many of the latest developments and trends are based at least in part on the successful implementation of a plasma process. Plasma treatments have demonstrated unique benefits and potential for environmental remediation and protection technologies, for medical therapies, and towards agriculture. The range of applications is steadily growing, based on dedicated research and development by a committed research community. However, continuing progress requires the ongoing support and interest of the societies that benefit from the accomplishments. [ABSTRACT FROM AUTHOR]

We introduce the atmospheric pressure plasma treatment as a suitable procedure for in-line industrial application of rabbit fibres pre-treatment. Changes of rabbit fibre properties due to the plasma treatment were studied in order to develop new technology of plasma-based treatment before felting. Diffuse Coplanar Surface Barrier Discharge (DCSBD) in ambient air at atmospheric pressure was used for plasma treatment. Scanning electron microscopy was used for determination of the fibres morphology before and after plasma treatment. X-ray photoelectron spectroscopy and attenuated total reflectance-Fourier transform infrared spectroscopy were used for evaluation of reactive groups. The concentration of carbon decreased and conversely the concentration of nitrogen and oxygen increased after plasma treatment. Aging effect of plasma treated fibres was also investigated. Using Washburn method the significant increase of fibres wettability was observed after plasma treatment. New approach of pre-treatment of fibres before felting using plasma was developed. Plasma treatment of fibres at atmospheric pressure can replace the chemical method which consists of application of strong acids on fibres. [ABSTRACT FROM AUTHOR]

This paper reports on the use of spectroscopic ellipsometry to characterise the initial nucleation stage of the atomic layer deposition of the anatase phase of titanium dioxide on silicon substrates. Careful control and analysis of the ellipsometric measurements enables the determination of the evolution of crystallite diameter and surface density in the nucleation stage before a continuous film is formed. This growth behaviour is in line with atomic force microscopy measurements of the crystallite size. The crystallite diameter is a linear function of the number of ALD cycles with a slope of approximately 1.7 Å cycle −1 which is equivalent to a layer growth rate of 0.85 Å cycle −1 consistent with a ripening process which increases the crystallite size while reducing their density. The crystallite density decreases from ∼3 × 10 17 m −3 in the initial nucleation stages to ∼3 × 10 15 m −3 before the film becomes continuous. The effect of exposing the substrate to a diffuse coplanar surface barrier discharge in an air atmosphere before deposition was measured and only small differences were found: the plasma treated samples were slightly rougher in the initial stages and required a greater number of cycles to form a continuous film (∼80) compared to the untreated films (∼50). A thicker layer of native oxide was found after plasma treatment. [ABSTRACT FROM AUTHOR]

The atmospheric pressure ambient air and oxygen plasma treatment of flat aluminum sheets using the so-called Diffuse Coplanar Surface Barrier Discharge (DCSBD) were investigated. The main objective of this study is to show the possibility of using DCSBD plasma source to activate and clean aluminum surface. Surface free energy measurements, X-ray photoelectron spectroscopy (XPS), Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (SEM/EDX) and Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) were used for the characterization of the aluminum surface chemistry and changes induced by plasma treatment. Short plasma exposure times (several seconds) led to a significant increase in the surface free energy due to changes of its polar components. Various ageing effects, depending on the storage conditions were observed and discussed. Effects of air and oxygen plasmas on the removal of varying degrees of artificial hydrocarbon contamination of aluminum surfaces were investigated by the means of EDX, ATR-FTIR and XPS methods. A significant decrease in the carbon surface content after the plasma treatment indicates a strong plasma cleaning effect, which together with high energy efficiency of the DCSBD plasma source points to potential benefits of DCSBD application in processing of the flat aluminum surfaces. [ABSTRACT FROM AUTHOR]

A novel type of dielectric barrier discharge, the so called Diffuse Coplanar Surface Barrier Discharge (DCSBD), has been used for the treatment of glass surfaces prior to their bonding with a UV-curing acrylate adhesive. The DCSBD is a source of diffuse, atmospheric-pressure “cold” plasma with power densities reaching ~ 100 W/cm 3 even in strong electronegative gases (e.g. pure oxygen) without any admixture of helium or argon. The plasma is generated in a thin, ~ 0.5 mm thick layer suitable for the treatment of flat materials like glass or polymeric foils. The plasma treatment of glass results in an overall decrease in organic contamination of the surface and, possibly, in an increase in the surface density of –OH groups promoting reactions on the glass surface, both effects being beneficial for adhesive properties of the glass surface. Plasma treated adhesive joints have been subjected to mechanical testing according to the ISO 4587 standard. Results indicate more than 45% improvement in the plasma treated joints adhesive strength, when compared to the untreated reference joints. Moreover, the different cleaning protocols used indicate, that it will be possible to substitute distilled water instead of ethanol in the cleaning procedure, which is a rather expensive and hazardous chemical. [ABSTRACT FROM AUTHOR]

In this paper the effect of plasma treatment in dependence of the different crystallographic orientation of silicon surface, (1 0 0) plane and (1 1 1) plane is studied. Plasma treatment was realized in atmospheric pressure plasma generated by diffuse coplanar surface barrier discharge in ambient air. The changes of surface morphology, wettability and chemical structure were investigated by means of the AFM measurement, contact angle measurement and XPS, respectively. It was proved that plasma roughening of c-Si depends on the crystallographic orientation. The wettability of c-Si after plasma treatment was improved independently on the orientation however oxidation of Si surface was also observed. [ABSTRACT FROM AUTHOR]

Poly(2-oxazolines) (POx) are an attractive material of choice for biocompatible and bioactive coatings in medical applications. To prepare POx coatings, the plasma polymerization represents a fast and facile approach that is surface-independent. However, unfavorable factors of this method such as using the low-pressure regimes and noble gases, or poor control over the resulting surface chemistry limit its utilization. Here, we propose to overcome these drawbacks by using well-defined POx-based copolymers prepared by living cationic polymerization as a starting material. Chemically inert polytetrafluoroethylene (PTFE) is selected as a substrate due to its beneficial features for medical applications. The deposited POx layer is additionally post-treated by non-equilibrium plasma generated at atmospheric pressure. For this purpose, diffuse coplanar surface barrier discharge (DCSBD) is used as a source of "cold" homogeneous plasma, as it is operating at atmospheric pressure even in ambient air. Prepared POx coatings possess hydrophilic nature with an achieved water contact angle of 60°, which is noticeably lower in comparison to the initial value of 106° for raw PTFE. Moreover, the increased fibroblasts adhesion in comparison to raw PTFE is achieved, and the physical and biological properties of the POx-modified surfaces remain stable for 30 days.

Hybrid mesoporous titania/silica electron-generating and transporting layers were prepared using wet-coating with a dispersion consisting of prefabricated titania nanoparticles and a methyl-silica binder. Titania/methyl-silica wet layers were deposited by inkjet printing and further mineralized by low-temperature atmospheric-pressure air plasma using diffuse coplanar surface barrier discharge (DCSBD) to form a titania/silica hybrid nanocomposite coating. Morphological analysis performed by scanning electron microscopy revealed no damage to the titania nanoparticles and chemical analysis performed by X-ray photoelectron spectroscopy disclosed a rapid decrease in carbon and increase in oxygen, indicating the oxidation effect of the plasma. The coatings were further electrochemically investigated with linear sweep voltammetry and chronoamperometry. The magnitude of photocurrent and photocatalytic activity were found to increase significantly with the plasma exposure on the order of 10s of seconds. The results obtained demonstrate the potential of DCSBD ambient air plasma for fast and low-temperature mineralization of titania mesoporous coatings.