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For high-quality black & white printing realized with an electrophotography printing machine, it is necessary to prepare the printing substrate. For optimal adhesion of the black liquid electrophotography ink to the printing substrate, it is necessary to apply additional treatment to meet ideal substrate surface tension by means of corona treatment and/or coating with fluid for regulating the surface tension (primer). This paper examines the influence of the corona power and the thickness of used fluid for the regulation of surface tension on the achromatic digital reproduction quality. Within the electrophotography printing process, this implies determining the differences in the colour gamut volume, the structure of characteristic screening elements, the amplitude-modulated screening, and the increase in the number of colour separations. The results show that the optimal colour tone values, colour gamut, and dot gain, high quality of digital prints will be realized without the use of the fluid for the regulation of surface tension and without activation of the corona power. That confirms that the FOGRA values for industrial standards can be used for quality electrophotography printing.

© 2022 Authors.With the increasing importance of flexible packaging in recent years, the trend of packaging printing in the printing industry has increased. The most widely used printing systems in flexible packaging printing are flexo and rotogravure printing. Although rotogravure printing is as high quality and fast as flexo printing, it has made flexo printing more preferable because the printing preparation processes take longer and are more costly. Flexo printing is a high printing system, and it is a printing system that is widely used especially in corrugated cardboard and flexible packaging printing. In flexo printing, the main factors affecting quality are the material to be printed and its physical properties. In flexo printing, the main factors affecting quality are the material to be printed and its physical properties. In particular, the surface structure of plastic film and metallized packaging substrates with low surface energy is expected to be ink-retaining. Because the surfaces of synthetic plastic films and metallized foils have a smooth and slippery structure, preventing printing inks from sticking. Because the binder in the structure of the ink does not have a rough surface to penetrate. In order for plastic films to be printed, their surfaces must have certain properties. For this, surface improvement process called corona is applied to these material surfaces. With this process, the film material surfaces are made micro-rough and the ink adheres to the surface better and is more resistant to external factors. It should be borne in mind that the surface of a film material that has undergone a corona treatment may deteriorate over time unless it is printed on. Because the effectiveness of the corona treatment is time-limited and the surface energy inevitably decreases after a while. They are also affected by environmental conditions such as temperature and humidity. In this study, to show the importance of corona surface coating, test prints were made with flexo printing on corona treated film materials whose corona became insufficient due to time. In the examination of the microscopic images of the test prints, it was observed that the ink adhered very well and was resistant to external factors on the surfaces where the corona treatment was adequately applied. On the other hand, it was determined that the ink color intensity decreased and the print quality deteriorated in the material with insufficient corona after the corona period. As a result, in printing systems, the surface energies of the plastic films must be approximately 10 mN/m higher than the surface tension of the ink during the printing process, in order to maintain good printing quality and unchanged throughout the printing, and for this, the surface energies of the plastic films must be increased by corona surface treatment. demonstrated on test prints and microscopic images of prints.

In this work, poly(lactic acid) (PLA)/gelatin/PLA multilayer films supplemented with cellulose nanocrystals and antioxidant extract from almond shell (AS) by-products were developed by solvent casting technique for active food packaging. The almond shell antioxidant extract (ASE) was obtained by microwave-assisted extraction, while cellulose nanocrystals (CNCs) were extracted from AS by a sequential process of alkalization, acetylation and acid hydrolysis. Four formulations were obtained by adding 0 (control), 6 wt.% of ASE (FG/ASE), 4.5 wt.% of CNCs (FG/CNC) and 6 wt.% + 4.5 wt.% of ASE + CNCs, respectively, (FG/ASE + CNC) into fish gelatin (FG). PLA/FG/PLA multilayer films were prepared by stacking two outer PLA layers into a middle FG film. A surface modification of PLA by air atmospheric plasma treatment was optimized before multilayer development to improve PLA adhesion. Complete characterization of the multilayers underlined the FG/ASE + CNC formulation as a promising active reinforced packaging system for food preservation, with low values of transparency, lightness and whiteness index. A good adhesion and homogeneity of the multilayer system was obtained by SEM, and they also demonstrated low oxygen permeability (40.87 ± 5.20 cm3 mm m−2 day) and solubility (39.19 ± 0.16%) values, while mechanical properties were comparable with commercial plastic films. The developed multilayer films were applied to Hass avocado preservation. The initial degradation temperature (Tini), DSC parameters and in vitro antioxidant capacity of the films were in accordance with the low peroxide and anisidine values obtained from avocado pulp after packaging for 14 days at 4 °C. The developed PLA/FG/PLA films supplemented with 6 wt.% ASE+ 4.5 wt.% CNCs may be potential bioactive packaging systems for fat food preservation. This research was funded by Conselleria de Educación (Spain), APOSTD/2016/093 Postdoctoral Research Training Grant.

Functional surfaces have great significance for improving the performance of bio-devices. The selection of appropriate ways to functionalise the surfaces of the polymers used for bio-devices are in great demand. In particular, cyclic olefin copolymer (COC) and cyclic olefin polymers (COP) are emerging substrates for bio-devices and possess superior chemical resistance than other polymeric substrates such as polycarbonate (PC). These polymer substrates often require surface modification to provide the functionality required. Here, we present a means to functionalise the surfaces of these polymers by a corona discharge treatment method. The water contact angle (WCA) of as received PC, COC and COP was found to be around 80°, 96° and 93°, respectively. The WCA of PC, COC and COP is reduced by 40%, 46% and 44%, respectively when treated with corona dose of 95 W min/m2. The WCA of PC, COC and COP was further reduced by increasing the corona dosage. The reduction of WCA is found mainly due to the incorporation of oxygen-related functionalities (such as carboxylic, carbonyl or aldehyde groups) as confirmed by high-resolution X-ray photoelectron spectroscopy (XPS) and Time-of-flight secondary mass spectrometry (ToF-SIMS). The oxygen to carbon (O/C) ratio is clearly increased after the corona treatment confirming the depletion of carbon on the functional surfaces. The functionality of surfaces obtained by corona treatment could be useful in the development of new bio-devices.

Pyroelectric energy harvesting is one of the more recent and promising solid-state approaches for directly converting time-dependent temperature fluctuations into electric energy. Conventional printing technologies can offer many advantages for the production of pyroelectric thin-film-based devices, such as low cost, low temperature, the use of flexible substrates and shaping at the same time as deposition. Nevertheless, some issues related to low printed thickness and film-forming microstructure control need to be addressed. In this exploratory study, the possibility of exploiting the highly attractive gravure printing process for the potential industrial manufacture of flexible polyvinylidene fluoride (PVDF) thin-film pyroelectric devices was investigated. By the use of corona pre-treatment of the printing substrate and low-temperature polar solvent evaporation, multilayer gravure-printed PVDF pyroelectric devices were successfully manufactured for the first time, achieving a maximum generated current of 0.1 nA at 2.5 K/s from a device with an active area of 1 cm2. Considering the very low thermal inertia and performance scaling by the area expected for pyroelectric thin-film-based devices, combined with the upscaling potential of roll-to-roll gravure printing, our results provide new opportunities for on-demand, low-cost pyroelectric device manufacture and their integration in hybrid harvesters.

Die Kassenärztlichen Vereinigungen haben dazu aufgerufen, Corona-Ambulanzen aufzubauen. Dort sollen gezielt Patienten mit einer möglichen Corona-Infektion behandelt werden. Im Folgenden wird der Aufbau einer Corona-Ambulanz beschrieben und ein Ausblick gegeben, wie die weitere Entwicklung der ambulanten Behandlung in der Corona-Krise aussehen könnte.

Ethanol separation factor and total flux for a fabricated composite polydimethylsiloxane/polyethersulfone polyvinylpyrrolidone (PDMS/PES.PVP) membrane in the pervaporation process were obtained at 6.25 and 440 g/m2 h, respectively. In order to improve the separation of ethanol as a renewable resource from water, the composite PDMS surface was modified by corona treatment, and the treated surface was coated by multi-walled carbon nanotubes (MWCNTs). Implementation of corona treatment for surface modification leads to enhancement in the ethanol separation factor using a MWCNT surface-coated membrane. Based on the obtained data, for a corona time of 6 min and corona input power of 360 W, the ethanol separation factor was improved from 6.25 to 9.3 and also a total flux of 280 g/m2 h was obtained. Therefore, application of the novel fabricated PDMS/PES.PVP composite membrane with surface modification by corona treatment and MWCNT coating in the pervaporation process at the desired condition has significantly improved the ethanol separation factor (48.8%).

Much research has been carried out to improve the wettability and to overcome the low adhesion of tire rubber for use in developing new building materials, such as wood-cement panels. Corona surface treatment (air plasma) of rubber particles was used in this study with various application times to improve adhesion and the interface between the particles and the cementitious matrix. Another aspect evaluated in this study was the partial replacement of wood particles by tire rubber waste in wood-cement panels. The particulate rubber residue was subjected to various corona application times to determine the most suitable treatment; the samples showed the most desirable qualities after 20 min of air plasma treatment. Then, panels were produced using Pinus oocarpa particles associated with various contents of tire rubber after corona treatment. Overall, after 20 min of air plasma treatment, the wettability and adhesion properties of tire rubber waste improved. The use of 5% rubber to replace pine wood in wood-cement panels led to a substantial improvement in the physical-mechanical properties evaluated, making its production feasible and promoting the reuse of a material harmful to the environment.

Silicone rubber is widely used as the housing material of composite insulator for outdoor high-voltage insulation. However, corona-induced aging in silicone rubber contributes to the ingress of water or moisture, which finally leads to fracture of a composite insulator. To investigate water transportation in silicone rubber helps to shed light upon the insulator fracture mechanism. In this work, water transportation behaviors in silicone rubber treated by different applied voltages of corona discharge were systematically studied using electrochemical impedance spectroscopy (EIS). Low voltages (3, 4 kV) of corona treatments result in growing value of $$f_{\theta \mathrm{min}}$$ in Bode phase angle, indicative of severer degree of surface delamination. After 5 kV of corona treatment, water can finally diffuse through the silicone rubber, and then induces double-layer capacitance ( $$C_{\mathrm{dl}}$$ ) and the charge transfer resistance ( $$R_{\mathrm{ct}}$$ ) in EIS spectra. For high-voltage ( $$\ge 6\ \hbox {kV}$$ ) corona-exposed samples, great number of surface cracks are observed, and then Warburg impedance appears in EIS spectra on initial period of immersion, suggesting a direct water transportation process. The polar groups generated in silicone rubber during corona exposure also facilitate this water diffusion process. Calculated water diffusion coefficients show a sharp increase between 5 and 6 kV, which serves as an indicator for percolation of cracks or defects in bulk of silicone rubber.

The influence of the structure and physico-chemical properties of chitosan/casein multilayer films on their potential use for drug delivery systems was investigated. The multilayer films were prepared using layer-by-layer self-assembly, whereby chitosan and casein were deposited onto poly(lactic acid) substrates pretreated with either a positive or a negative corona. The corona discharge system consisted of a corona electrode, a grounded plate and a grid. The deposition was studied by ATR FT-IR, AFM, and surface energy measurements. ATR FT-IR spectra proved the formation of polyelectrolyte chitosan — casein complexes. The increasing content of chitosan and casein with increasing number of bilayers was further confirmed by XPS analysis. The surface topography was examined by AFM and the average roughness was evaluated. A comparative analysis of the experimental results was performed and the most appropriate substrate corona treatment for the irreversible binding of the chitosan/casein polyelectrolytes was determined.

To achieve industrially viable fabrication process for perovskite-based solar cells, every process step must be optimized for maximum throughput. We present a study of substituting laboratory-type UV-Ozone surface treatment with a high-throughput Corona treatment in a scalable perovskite solar cell fabrication process. It is observed that water contact angle measurements provide insufficient information to determine the necessary dose of Corona or UV-Ozone treatment, but the surface carbon signal measured by x-ray photoelectron spectroscopy accurately identifies when surface contamination has been completely removed. Furthermore, we observe highly accelerated de-contamination of ZnO surfaces by UV-Ozone treatment. The effect can be explained by photocatalytic O2− ion generation indicating that UV-Ozone treatment is also applicable in high-throughput processing.

Polymers/metal laminates are often used to improve physical and mechanical properties, especially those required in building applications. A flat aluminum composite panel (ACP) consisted mainly of two thin metal sheets usually made of aluminum (Al) and a non-metal core, such as polyethylene (PE). The lack of adhesion associated with the low wettability of PE is a serious problem. An eco-friendly, dry, non-destructive corona treatment technique can be applied to solve this problem. In this work, the use of a corona treatment to enhance the adhesion properties of linear low-density polyethylene (LLDPE) was studied. The changes in surface and adhesion properties were thoroughly analyzed using various analytical techniques and methods to obtain the optimal parameters for corona discharge using contact angle measurements, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). AFM force adhesion measurements were used to analyze the effect of the corona treatment on the adhesion enhancement of LLDPE, and the peel tests confirmed a significant increase in peel resistance in the LLDPE/Al laminate. A synergy effect from using the corona treatment in combination with an ethylene acrylic acid dispersion primer was observed. - 2017 Elsevier B.V. This publication was made possible by an Award JSREP 07-022-3-010 from the Qatar National Research Fund (a member of The Qatar Foundation). The statements made herein are solely the responsibility of the authors. Scopus

In plywood manufacturing, the surface characteristics of veneers play a critical role in achieving appropriate bonding performance. An inactivated wood surface caused by oxidation or migration of wood extractives has been shown to lead to an insufficient bonding quality. In this study, inactivated birch and spruce veneer surfaces were activated with corona and chemical NaOH treatments. The effects of the treatments were determined by contact angle measurements and bond quality tests conducted with Automated Bonding Evaluation System (ABES). In addition, the mechanical properties of the plywood produced from the treated veneers were evaluated. The results showed that the corona treatment remarkably increased the wettability of the veneer surface and bond quality of both the spruce and birch veneers evaluated by ABES. The corona treatment also improved the mechanical properties of the birch plywood, but the spruce plywood properties were not affected as much. Soaking veneers in NaOH improved the wettability, but the bond strength was lower than that of the references.

A porous filter comprised of polypropylene (PP)/polyamide 6 (PA6) micro-/nano-fibers has been produced from a novel melt-based plastics co-extrusion and exfoliation process technology for the separation of microscale water droplets from diesel fuel. The filter media have a mean pore size of 11 µm, a porosity greater than 85%, a surface area of more than 12x the value for an electrospun medium, tough mechanical properties, and a contact angle of 124°, all of which make the co-extruded filter a superior fuel filter. An improvement in water-separation from diesel fuel feed stream from 62–85% water-removal was achieved by the co-extruded and exfoliated PP/PA6 fibrous media in comparison to a commercial fuel filter under identical test conditions and pressure drop. The fuel/water separation mechanism was identified as a capture-coalescence-release process. It has been found that the highest performance fuel filter required small pore sizes and large surface area for droplet capture, due to the hydrophobic nature of materials required for successful droplet release, and a high porosity for minimizing flow resistance. In addition to the proof of concept water separation demonstration, studies into (a) the effect of increasing the barrier substrates thickness and (b) surface corona treatment to alter the hydrophilicity of media surfaces on the filtration efficiency co-extruded, exfoliated filters are reported.

In this study, we present solution-based processes for producing copper (Cu) meshes which can be utilized as transparent conductive electrodes (TCEs) for flexible film heaters. The surface modification of polyethylene terephthalate (PET) substrates was done via corona treatment at atmospheric pressure and room temperature. The Cu layer was deposited on the corona-treated PET substrate via electroless plating and then patterned via lithography to have mesh dimensions of a 200 μm line-to-line spacing and a 6 μm line width. Also, graphene was coated on the Cu mesh via electrophoretic deposition (EPD). The chemical and physical changes in the PET surfaces were characterized according to the corona treatment conditions. The measurements of contact angles and surface energies of the corona-treated PET substrates indicated that the PET surfaces changed from hydrophobic to hydrophilic after corona treatment, leading to the improvement in the adhesion between the PET substrates and the Cu meshes. The flexibility of the Cu meshes was inspected by performing bending and twisting tests and by directly measuring the adhesion strength between the Cu layers and the PET substrates through scratch tests. The effects of graphene coating on the characteristics of the Cu meshes were examined in terms of their surface morphologies, electrical sheet resistances, transmittances and reflectances in the visible-light wavelength range, and color differences. Finally, the film heaters produced by employing the graphene-coated Cu meshes yielded a temperature rise over 85 °C with a response time shorter than 20 s.

Lignocellulosic materials have a complex polymeric structure, so, to obtain a high yield of glucose by hydrolysis reactions is necessary a pretreatment of the material. In this work, the effect of pretreatment corona (electric discharge) on different properties in three lignocellulosic materials (microcrystalline cellulose, cellulose pulp and bagasse) was evaluated. corona treatment was applied in three different exposure times (2, 6 and 10 minutes). Crystallinity, obtained by X-ray diffraction, showed a significant increase in samples of bagasse after pretreatment. No changes in acidity of materials was observed. Cationic and anionic tests indicate that the surface of bagasse is negatively charged after pretreatment. Amount of methylene blue adsorbed in the materials decreased with increasing of exposure time. Acid hydrolysis of materials with and without pretreatment were evaluated in amount of total reducing sugars (%TRS). A small decrease in %TRS occurred after pretreatment corona mainly in bagasse samples. HPLC analysis of hydrolysis products of pretreated bagasse showed higher yields in glucose, a raw material of interest for second generation ethanol.

RESUMO A indústria de polímeros tem passado por muitos avanços na última década, dentre eles, podem-se citar as inovações em processamento e no uso de aditivos, o que permite que eles sejam utilizados em diversas aplicações, especialmente quando expostos ao ambiente externo. Porém, para algumas aplicações específicas, o polímero precisa ser submetido a tratamentos de superfície, com o objetivo de aumentar a rugosidade superficial. Por este motivo, muito ainda precisa ser estudado no que diz respeito aos aditivos utilizados no processamento de polímeros quando ele é submetido a processos de transformação, podendo-se citar o tratamento corona. Desta forma, este trabalho tem o objetivo de avaliar as modificações estruturais causadas em aditivos estabilizantes presentes em filmes poliméricos quando são submetidos a tratamento corona. Três diferentes absorvedores de UV foram avaliados: benzofenona, benzotriazol e triazina. Os filmes foram processados por spin coating e submetidos à radiação ultravioleta, com o objetivo de simular a exposição externa do polímero e a tratamento corona. Analisando os resultados obtidos, pode-se perceber que o único aditivo que resistiu às condições de tratamento foi o benzotriazol, mantendo a absorção da radiação ultravioleta, mesmo após o tratamento corona e protegendo o polímero da degradação UV. Os outros aditivos sofreram processos degradativos, causadas pelo tratamento corona, e a absorção da radiação ultravioleta, apresentada previamente, deixa de existir. ABSTRACT The polymer industry has undergone many advances in the last decade, among them, innovations in the processing and in the use of additives, which enable the use of polymers in several areas, especially, when exposed to external environment. However, for some specific applications, the polymer must be submitted to surface treatments in order to increase its superficial roughness. Then, much remains to be studied regarding the behavior of these additives when exposed to transformation processes in which the polymers are normally subjected, as for example, the corona treatment. Thus, this study aims to evaluate the structural modifications in stabilizing additives present in polymeric films, when subjected to corona treatment. Three different UV absorbers additives were evaluated: benzophenone, benzotriazole and triazine. The films were processed by spin coating and subjected to ultraviolet radiation, in order to simulate the external exposition of the polymer, and corona treatment. Analyzing the results obtained, it was realized that the only additive that resisted to thetreatment conditions was benzotriazole, maintaining the absorption of ultraviolet radiation even after corona treatment and protecting the polymer from UV degradation. The other additives suffered degradation processes, caused by corona treatment, and the absorption of ultraviolet radiation presented earlier, ceases to exist.

Surface modification may lead activated carbon (AC) to take on different properties. This study aimed to promote surface modification of activated carbons using corona treatment (electrical discharge). In this study, powdered commercial activated carbon was used. Activated carbons were subjected to corona treatment at different exposure times (2, 5, 8 and 10 min) at 4.5 cm height from the source. To observe differences promoted by treatment, activated carbons were analyzed by acidity, surface functional groups, Fourier Transform Infrared Spectroscopy (FTIR), elemental analysis (CHN), proximate analysis and thermogravimetry. Corona treatment impacted surface chemistry of activated carbons. There was a trend of increasing surface acidity according to exposure time. There were changes in functional groups, increasing carboxyl acid and decreasing lactone and phenol groups. FTIR analysis showed peaks in the bands at 3500, 1650 and 1300 cm-1. Increase of oxygen content and decrease of carbon content were also found. Immediate analysis followed similar tendency for volatile and fixed carbon content. There were also differences in thermogravimetry analysis. Treated activated carbons were different compared to virgin activated carbon. This difference was performed by surface oxidation. Thus, this study showed that corona treatment caused surface modifications and might impact adsorption process.

Low surface energy and poor adhesion are well-known characteristics of polypropylene (PP). Surface treatments such as plasma, corona, and laser are usually applied to overcome these limitations. However, current studies highlight the incorporation of hydrophilic or amphiphilic polymers into hydrophobic low-surface-energy polymers as an alternative for increasing surface energy and thus improving adhesion. Lignin could be a promising amphiphilic polymer for use in increasing surface energy. In this work, PP/kraft lignin composites were obtained by incorporating up to 5 wt% of kraft lignin (KL) into a PP matrix. Corona treatment was applied to pristine PP and composites surfaces. Contact angle measurements and peeling tests were carried out to investigate the effects of KL incorporation and corona treatment on the surface energy and the mechanical strength of adhesion. Differential scanning calorimetry (DSC) was used to evaluate the PP’s crystallinity index and recrystallization temperature and to dismiss their effects on the surface energy changes. Scanning electron microscopy (SEM) was applied to investigate the lignin dispersion. The results show that KL incorporation has potential as a method to improve the surface energy of PP, improve its poor adhesion, and enhance the effects of corona treatment.

In this research, Carbon black particles were applied on the woven fabric by the knife coating technique and pretreatment using plasma corona discharge to build-up conductive cotton-polyester (CVC 50%) fabric electromagnetic shielding material. This paper describes the making of anti-radiation weaving fabric using plasma technology. The anti-radiation patch was developed by first modifying the textile fabric's surface using atmospheric pressure plasma technology using tip-cylinder electrode configuration. The plasma corona discharge was generated using high voltage electricity with asymmetrical electrodes (tip and cylinder). The treated weaving fabric using plasma was then coated with carbon black ink. This research indicates that an anti-radiation weaving fabric was successfully shielded electromagnetic radiation from an electronic device.

In this study, the surface of polyethersulfone (PES) microfiltration membranes was modified by corona discharge plasma in order to improve the antifouling properties and separation performance of the membranes. For this purpose, the PES microfiltration membranes were fabricated by the vapor-induced phase inversion coupled with the nonsolvent-induced phase inversion technique. The effect of the corona power and exposure time on the surface properties and separation performance of the membranes for microfiltration of skim milk was studied. The analysis of the filtration transport resistances was also performed to evaluate the antifouling performance of the corona-modified membranes. The results indicated that the exposure time and applied power of the corona treatment had effects on the membrane surface modification as the surface hydrophilicity, wettability, and morphology of the membranes were significantly changed depending on the corona modification conditions. Moreover, the analysis of the tran...