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Active food packaging incorporated with natural plant extracts as food preservatives, which will totally replace chemical preservatives gradually, are of major interest. Sequentially to our and other scientists’ previous work, in this paper we present the results of a study on the development of a novel active food packaging film based on the incorporation of a natural-halloysite/carvacrol-extract nanohybrid with the commercially used low-density polyethylene. The corona-treatment procedure was employed to incorporate a natural preservative on to the optimum final film. Packaging films are formatted with and without incorporation of natural-halloysite/carvacrol-extract nanohybrid and are coated externally, directly or via corona-treatment, with carvacrol essential oil. Mechanical, physicochemical, and preservation tests indicated that the low-density polyethylene incorporated perfectly with a natural-halloysite/carvacrol-extract nanohybrid. The extra external coating of the film with pure carvacrol extract using the corona-treatment technique led to approximately 100% higher Young Modulus values, slightly decreased ultimate strength by 20%, and exhibited almost stable elongation at break properties. The water vapor and oxygen properties were increased by 45 and 43%, correspondingly, compared to those of pure low-density polyethylene film. Finally, the antioxidant activity of the corona-treated film increased by 28% compared to the untreated film coated with carvacrol because of the controlled release rate of the carvacrol.

Active food packaging incorporated with natural plant extracts as food preservatives, which will totally replace chemical preservatives gradually, are of major interest. Sequentially to our and other scientists' previous work, in this paper we present the results of a study on the development of a novel active food packaging film based on the incorporation of a natural-halloysite/carvacrol-extract nanohybrid with the commercially used low-density polyethylene. The corona-treatment procedure was employed to incorporate a natural preservative on to the optimum final film. Packaging films are formatted with and without incorporation of natural-halloysite/carvacrol-extract nanohybrid and are coated externally, directly or via corona-treatment, with carvacrol essential oil. Mechanical, physicochemical, and preservation tests indicated that the low-density polyethylene incorporated perfectly with a natural-halloysite/carvacrol-extract nanohybrid. The extra external coating of the film with pure carvacrol extract using the corona-treatment technique led to approximately 100% higher Young Modulus values, slightly decreased ultimate strength by 20%, and exhibited almost stable elongation at break properties. The water vapor and oxygen properties were increased by 45 and 43%, correspondingly, compared to those of pure low-density polyethylene film. Finally, the antioxidant activity of the corona-treated film increased by 28% compared to the untreated film coated with carvacrol because of the controlled release rate of the carvacrol. [ABSTRACT FROM AUTHOR]

Corona treatment (CT), a surface treatment widely used in the plastic industry, can be used to alter the properties of cassava starch. In the present work, CT was performed on dry granular starch (DS), water-suspended humid granular starch (HS), and gelatinized starch (GS). Different properties and structural characteristics of treated starches were studied. A lowering in pH was generally observed after CT and the rheological properties depended on the starch presentation. A reinforcement of DS and HS samples after CT was deduced from higher viscosity values in flow assays and viscoelastic moduli, but weak gels were obtained when CT was applied to GS. Changes in the A-type polymorphic structure, as well as a drop in relative crystallinity, were produced by CT for DS and HS. Additionally, changes in O-H and C-O-C FTIR bands were observed. Therefore, CT can be applied for starch modification, producing predominantly cross-linking in the DS and de-polymerization in the HS. Casting films made from the modified DS showed higher tensile strength and lower hydrophilicity, solubility, water absorption capacity, and water vapor permeability. Thus, the DS cross-linking induced by CT improved mechanical characteristics and hydrophobicity in edible films, which can be better used as packaging materials. [ABSTRACT FROM AUTHOR]

Polyelectrolyte multilayers (PEMs) deposited on porous composite polylactic acid/poly(ε-caprolactone) (PDLA/PEC) substrates were studied. The substrates were previously charged in a corona discharge. Time dependences of the normalized surface potential for positively and negatively charged electrets were investigated. The morphology of the obtained porous substrates was examined by means of scanning electron microscopy (SEM). The chitosan and the casein polyelectrolytes were deposited on the substrates using the layer-by-layer (LbL) technique. The drug loading efficiency and the release kinetics were determined spectrophotometrically. [ABSTRACT FROM AUTHOR]

Corona treatment (CT), a surface treatment widely used in the plastic industry, can be used to alter the properties of cassava starch. In the present work, CT was performed on dry granular starch (DS), water-suspended humid granular starch (HS), and gelatinized starch (GS). Different properties and structural characteristics of treated starches were studied. A lowering in pH was generally observed after CT and the rheological properties depended on the starch presentation. A reinforcement of DS and HS samples after CT was deduced from higher viscosity values in flow assays and viscoelastic moduli, but weak gels were obtained when CT was applied to GS. Changes in the A-type polymorphic structure, as well as a drop in relative crystallinity, were produced by CT for DS and HS. Additionally, changes in O-H and C-O-C FTIR bands were observed. Therefore, CT can be applied for starch modification, producing predominantly cross-linking in the DS and de-polymerization in the HS. Casting films made from the modified DS showed higher tensile strength and lower hydrophilicity, solubility, water absorption capacity, and water vapor permeability. Thus, the DS cross-linking induced by CT improved mechanical characteristics and hydrophobicity in edible films, which can be better used as packaging materials.

Copyright of Journal of Dalian University of Technology / Dalian Ligong Daxue Xuebao is the property of Journal of Dalian University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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. [ABSTRACT FROM AUTHOR]

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.

Diapause is an important biological characteristic for many insect species to adapt to adverse environmental conditions and maintain the continuity of the race. Compared with the traditional hydrochloric acid or/and cold storage treatment methods, the artificial corona incubation technology of silkworm (Bombyx mori) eggs has many advantages including, the absence of pollution, easy operation and safety. However, this technology has not yet been applied in sericulture. In this study, we developed a novel artificial corona instrument to successfully disrupt the diapause of newly laid and refrigerated eggs from various Chinese and Japanese lineage silkworm strains. Subsequently, we invented a very early corona treatment (VECT) strategy to prevent the diapause of newly laid silkworm eggs within 4 h of oviposition. The hatching rates of the larvae were more than 95% in all diapause silkworm strains, which was comparable to the effect of the traditional HCl treatment strategy. In addition, we developed a combination strategy of VECT and pre-blastoderm microinjection and successfully created transgenic silkworms in various diapause strains. The results of the current study can aid in improving the corona artificial incubation technology and promote its application in sericulture.

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Current study encompasses that the effect of corona treatment on the outer surface of transparent co‐extruded polyethylene films was at various levels by applying different wattages, in tandem with the blown film extrusion process. A maximum treatment of 42 dynes/cm was achieved at 4.5 KW of applied wattage. The heat seal joint strength of the films sealed at different combinations of treated/untreated surfaces was evaluated and an untreated/untreated surface combination was found to exhibit maximum strength (2.8 kgf/25 mm), while a treated/treated surface combination showed the minimum (1.41 kgf/25 mm) under identical conditions of sealing and testing. The peel adhesion to ascertain the treatment level on the treated surfaces was inspected by a standard Scotch tape method, and the results exhibited a linear relationship between the applied wattage and the pulling force of adhesion. The Fourier transform infrared spectroscopy (FTIR) spectra of the treated and untreated film samples in an attenuated total reflection (ATR) mode showed the peaks' characteristics mostly of polyolefin films. The morphologies of the treated surfaces displayed relatively rough surface compared to the untreated one. The barrier properties of the treated films in respect of water vapor and oxygen transmission rate do not undergo any appreciable change. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Gentle corona treatment conditions were applied to enhance the surface energy. • A rather low blending amount of additive could stabilize the film surface energy obviously. • Mechanism investigations were carried out for the co-treatment method. • Proper crystallization behavior and polar groups guarantee the stability of the surface energy. Abstract Corona and chemical treatment worked cooperatively for increasing and stabilizing the polyethylene film surface energy. Gentle and varied corona discharge treatment conditions were applied for each polyethylene film to reach 40 dynes/cm. A rather low blending amount of additive could stabilize the film surface energy obviously. Compared with neat PE film, of which the surface energy decreased to 36 dynes/cm at the 12th day, films blended with 1000 ppm A7-OH or PE-PEG 4k -PE showed stable surface energy (36–38 dynes/cm) over 150 days. The influence of industrial applied slipping agent was investigated as well. Morphological and chemical changes were studied by X-ray photoelectron spectroscopy (XPS) and Atomic Force Microscope (AFM). The surface energy was determined by the dyne pens. Mechanism investigation of hydrophilization and hydrophobic recovery processes showed that proper crystallization behavior and enough C O groups on the film surface guarantee satisfactory stability of the surface energy. [ABSTRACT FROM AUTHOR]

The main and new surface modification methods of activated carbon (AC) and their influence on application (adsorption capacity) were reviewed. Adsorption capacity is an important issue, contributing to hazardous substances environment management. According to literature, it is true that surface chemistry strongly affects adsorption capacity. Surface chemistry can be modified by several methods that lead to different activated carbon properties. Furthermore, adsorbate properties, and their relationships with surface structure, can impact adsorption properties. Surface modifications can be conducted by adding some atoms to the surface structure, making the surface more acidic or basic. Introduction of oxygen and ammonia atoms (chemical modification) are the main processes to make the surface more acidic and basic, respectively, although may bring chemical wastes to environment. Surface modification is done by chemical and physical modifications that lead activated carbons to present different properties. The main and new methods of chemical and physical modifications are compared and presented in this paper. Some new physical methods, like corona treatment, plasma discharge and microwave radiation, can be applied to cause surface modifications. Corona treatment can be a practical and new way to cause surface modification on an activated carbon surface. [ABSTRACT FROM AUTHOR]

A novel flexible pressure sensor, based on polydimethylsiloxane (PDMS) and eutectic gallium–indium (EGaIn) liquid metal, was developed for detecting various applied pressures. The sensor was fabricated with PDMS polymer-based electrode channels that are filled with EGaIn liquid metal. The liquid metal-based electrodes were designed to form four capacitors (C1, C2, C3, and C4). Conventional printed circuit board technology was used to manufacture the master mold to form the PDMS-based electrode channels. Corona discharge treatment was employed to bond the PDMS layers at room temperature, under atmospheric pressure. The capability of the fabricated pressure sensor was demonstrated by investigating the capacitive-based response of the device for varying applied pressures. Average capacitance changes ranging from 2.3% to 12.0%, 2.6% to 11.8%, 2.5% to 12.2%, and 2.7% to 13.1% when compared with the based capacitance of 14.1, 15.1, 13.8, and 13.3 pF were obtained for C1, C2, C3, and C4, respectively, for applied pressures ranging from 0.25 to 1.10 MPa. A linear relationship was obtained for the average capacitance change with a sensitivity of 0.11%/MPa and a correlation coefficient of 0.9975. The results obtained thus demonstrate the feasibility of employing liquid metal-based electrodes for the fabrication of flexible pressure sensing devices. [ABSTRACT FROM AUTHOR]

The aim of this investigation was to determine the role of negative direct current and alternating current (plasma) corona treatments in modification of bio-based dispersion barrier coatings and the response of replacing fossil-based binder with a thermoplastic bio-based binder (starch). The study emphasizes the importance of understanding and optimizing electric corona discharge in order to obtain high oxidation level without harming the substrate and causing unintentional treatment of the reverse side. The coatings were exposed to different corona treatment conditions using a novel developed sheet-fed laboratory-scale device. Corona-induced topographical, mechanical and surface chemical changes were observed from atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and contact angle and surface energy measurements. XPS results indicated further that partial starch decomposition occurred after plasma treatment. Coated surfaces became substantially smoother after both treatments suggesting that nanoparticle migration and re-orientation effects occurred. Additionally, reverse side effects and strike through were also discussed. [ABSTRACT FROM AUTHOR]

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 woodcement 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. [ABSTRACT FROM AUTHOR]

[Objectives] The aim was to investigate the effects of corona field and dielectric separation on the seed vigor of hybrid rice. [Methods] The seeds of 6 hybrid rice varieties were processed with corona field, dielectric separation and corona field + dielectric separation. [Results] When the field intensity was 200 km/m and the processing time was 4 min, the seed vigor was significantly increased. The seed vigor of Y Iiangyou 9918 (2014) increased the most, and the germination potential and the germination rate increased by 17 and 12 percentage points respectively compared to the control. Corona field reduced seed conductivity, and for seedlings, it decreased their MDA content, increased proline content, improved peroxidase activity, and enhanced root activity. When the rotating speed of the drum was 30 r/min, the dielectric separation voltage of 4 500 V could achieve good separation effect, and the vitality of seeds at different grades was significantly different. Under the optimized corona field combined with optimized voltage processing of dielectric separation, the seed vigor at all grades from the separation was significantly higher than that of the dielectric separation processing alone. The combined separation processing separated no seeds with germination rate of higher than 80% from the hybrid rice seeds with germination rate of lower than 60%, yet it could effectively separate the seeds with germination rate of higher than 80% from the hybrid rice seeds with germination rate of 65%--70%. After the combined processing, the germination rates of separated Grade I seeds of Wangliangyou 6 (2015), N Iiangyouhuazhan (2015), Wangliangyou 6 (2016) increased by 20, 15, 20 percentage points from the germination rates of the control, while the germination rates of N Iiangyouhuazhan (2016) and Y Iiangyou 9918 (2016), which had the germination rates of higher than 80%, increased by 3 and 9 percentage points from the control, suggesting insignificant separation effect. [Conclusions] This study provided a new technical approach for the processing of hybrid rice seeds. [ABSTRACT FROM AUTHOR]

Plant cellulose fiber polymer composites are readily applied in wide range of applications due to ecological and economical alternative to traditional materials. The considerable amount of residues and organic wastes from agricultural process are still employed as lower energy resource. Organic materials are generally disposed in composting, landfilling or anaerobic digestion. The utilization of these wastes in plant fiber composites shows significant alternative and environmental friendly in nature. The production of plant cellulose fiber composite with higher structural properties is optimized by interfacial bonding between polymer and reinforced fiber. The interface plays a vital role in regulating mechanical properties by distributing bonds and stress transferring, which is one of least understood element of composites. This paper presents the comprehensive review of fiber structures, different modification techniques to reduce the incompatibility between matrix and fiber, assessment of structure interface and bonding, clarifies the interfacial adhesion of cellulose fiber composites. [ABSTRACT FROM AUTHOR]

This research developed antibacterial food packaging sheets from biodegradable poly(lactic acid)/poly(butylene succinate) 90/10 wt% blend. The corona discharge energy via input current (in A) was set at three levels (4, 5, and 6 A) to investigate its influence on the coating content. Physical and chemical characteristics of treated surfaces were studied using scanning electron microscope, X-ray photoelectron spectroscopy, and contact angle measurement. A simple dip coating was carried out by immersing the sheets in chitosan solutions with four different concentrations (0.25, 0.50, 1.00, and 2.00% w/v). Chitosan content, antibacterial activity, and water vapour transmission rate were evaluated. Tensile tests were performed and results were statistically analyzed. We found that the sheets treated at 4 A corona discharge energy obtained the highest chitosan content while the sheets maintained elongation at break values similar to the untreated sheets. Chitosan coating had some water vapour permeation barrier and also mechanically reinforced the corona-treated sheets. Antibacterial activity tests against Staphylococcus aureus and Escherichia coli showed that chitosan coating inhibited the growth of both microorganisms as a function of chitosan coating content. [ABSTRACT FROM AUTHOR]

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 O 2 − ion generation indicating that UV-Ozone treatment is also applicable in high-throughput processing. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Retort pouch is one kind of flexible packaging which is made from plastic film or aluminum foil laminating together. Generally, retort pouches will use adhesive to combine each layer of film or foil together. If the lamination between each layer is not good enough, the delamination of each layer might occur. Therefore, the effects of corona treatment on surface of aluminum foil for retort pouch (PET/Al/CPP) were studied. This research was aimed to com- pare bond strength ability of Al/CPP layer, seal strength, and tensile strength of laminated film (PET/Al/CPP), both before and after sterilization. Moreover, it was aimed to compare the shelf life of laminated film (PET/Al/CPP) that held ketchup and tuna for a period of 7, 14, 21, and 30 days. There were five samples used in this experiment, the laminated film without corona treatment on Al surface and the laminated film with corona treatment on Al surface at 2, 2.5, 3, and 4 kW. The results showed that the laminated film with corona treatment (in all levels) on aluminum surface had higher bond strength, seal strength, and tensile strength than the laminated film without corona treatment on aluminum surface. The results of the shelf life of laminated film (PET/Al/CPP) that held ketchup and tuna paste for a period of 7, 14, 21, and 30 days showed that the bond strength ability of the film without corona treatment on aluminum decreased and the laminated film was delaminated on Al/CPP layer. In a way, the bond strength ability of laminated film with corona treatment (in all levels) on aluminum slightly decreased. It was also indicated that the level of voltage on corona treatment did not statistically affect bond strength ability of Al/CPP layer, and seal strength and tensile strength of laminated film (PET/Al/CPP). [ABSTRACT FROM AUTHOR]

This work makes a comparative study between the corona treatment and the traditional degumming process. For silk waste to be dyed, they must have good water absorption and mechanical strength. The results of the physical properties such as hydrophilicity and tensile strength are presented in relation to the two processes. The corona treatment promotes hydrophilicity and tensile strength compatible with the traditional degumming process, but with much less treatment time and no effluent generation. [ABSTRACT FROM AUTHOR]

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 transport resistances revealed that the cake resistance was the main resistance to transport and the fouling, cake and total filtration resistances for the corona-modified PES membranes were low in comparison to the neat PES membranes, which implies that the fouling tendency of the PES membranes modified by the corona air plasma was considerably reduced. [ABSTRACT FROM AUTHOR]

Different types of PLA films treated by corona are currently available in the market for coating or printing applications. However, data relative to its impact on PLA film properties are scarce and do not generally consider industrial scale production. The objective of this study was to assess the impact of corona treatment on the surface, structure and barrier properties of bi-oriented PLA films produced at industrial scale. Thus, a comparative study between corona treated (CT) and non-corona treated (NCT) PLA films was conducted. The surface of films was studied using Attenuated Total Reflectance Fourier Infrared Spectroscopy (ATR-FTIR), X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM) and goniometry measurements. The structure of films was analyzed with thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and uniaxial tensile analysis. The barrier properties of films to three gases (He, O 2 , CO 2 ) were also determined. This study unambiguously revealed that corona treatment led to modifications in both surface and bulk of PLA films. In particular, surface analysis displayed the well-known capability of corona treatment to chemically and physically modify the surface of PLA films at the nanometer scale by increasing polarity and roughness. The structural analysis displayed a slight increase in the crystallinity degree and slight modifications in mechanical properties of films. This probably originated from temperature increase associated to corona treatment, which favored physical changes ( e.g. relaxation, crystallization) of a part of the bi-orientated PLA chains, and therefore highlights the importance of such an industrial step on the film properties for packaging applications. As a result of these modifications, the barrier properties of films to three gases (He, O 2 , CO 2 ) are also slightly improved. [ABSTRACT FROM AUTHOR]

The uncoated side of dispersion-barrier-coated paperboards was exposed to positive and negative direct current corona treatments in order to confirm the occurrence of backside treatment and clarify its effects on the usability of the paperboard. The main component of the coating dispersions was hydroxypropylated potato starch and the effects of talc and styrene-butadiene latex additions on backside treatment were evaluated. Coatings with a high talc proportion showed excellent initial grease resistance, but corona-induced strikethroughs caused a drastic decrease in grease penetration time. The root-mean-square roughness measurements revealed moderate surface roughening at the backside, indicating thus backside treatment. The alterations in surface free energies and rapeseed oil contact angles confirmed the occurrence of backside treatment. The high polarization potential of latex played a key role in these observations. At the same time, the inertity of talc had a stabilizing effect but it did not prevent backside treatment completely. X-ray photoelectron spectroscopy results verified that backside treatment occurs also when the barrier-coated side of the substrate is treated with corona, indicating that a dispersion coating layer does not prevent this undesired phenomenon. Bearing in mind that expressing customized information or including personalized elements in food packages or disposable cups and plates is under great interest, it can be assumed the exposure of packaging materials to corona will become more common in the near future, and the need for optimizing bio-based packaging materials for such purposes is obvious. [ABSTRACT FROM AUTHOR]

Polypropylene films (PP) surface treated by corona discharge in air was analyzed to verify the changes on surface composition. The presence of oxidized polar groups on the film surface, mainly, C=O, C-O and COH, was confirmed by infrared spectroscopy (FTIR/ATR) and atomic force microscopy (AFM) revealed a dramatic change in the morphology and provided qualitative results of the chemical composition (new structures). Contact angle (q) of the PP films decreased after corona treatment indicating an increase in the wettability due to the polar groups formed. Extended treatment results of low molecular weight oxidized material into the surfaces and a smaller additional degree of modification in the wettability is obtained.

COVID-19, an extremely transmissible and pathogenic viral disease, triggered a global pandemic that claimed lives worldwide. To date, there is no clear and fully effective treatment for COVID-19 disease. Nevertheless, the urgency to discover treatments that can turn the tide has led to the development of a variety of preclinical drugs that are potential candidates for probative results. Although most of these supplementary drugs are constantly being tested in clinical trials against COVID-19, recognized organizations have aimed to outline the prospects in which their use could be considered. A narrative assessment of current articles on COVID-19 disease and its therapeutic regulation was performed. This review outlines the use of various potential treatments against SARS-CoV-2, categorized as fusion inhibitors, protease inhibitors, and RNA-dependent RNA polymerase inhibitors, which include antiviral drugs such as Umifenovir, Baricitinib, Camostatmesylate, Nafamostatmesylate, Kaletra, Paxlovide, Darunavir, Atazanavir, Remdesivir, Molnupiravir, Favipiravir, and Ribavirin. To understand the virology of SARS-CoV-2, potential therapeutic approaches for the treatment of COVID-19 disease, synthetic methods of potent drug candidates, and their mechanisms of action have been addressed in this review. It intends to help readers approach the accessible statistics on the helpful treatment strategies for COVID-19 disease and to serve as a valuable resource for future research in this area., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Objectives Poor interfacial adhesion between the fibers and resin matrix in the ultra high molecular weight polyethylene (UHMWPE) fiber reinforced composites (FRCs) is the main drawback of the composites. This study aims to evaluate the effect of corona and silane surface treatment of the fibers on the mechanical properties of the UHMWPE FRCs. Methods UHMWPE fibers were exposed to corona discharges for different periods of time (0 s, 5 s, 7 s). The surface characteristics of the UHMWPE fibers were investigated by attenuated total reflectance Fourier transformed infrared spectroscopy (ATR-FTIR), atomic force microscopy (AFM), scanning electron microscopy (SEM) and nanoindentation technique. The flexural strength and flexural modulus of the FRCs made of the treated fibers were determined on 2 mm × 2 mm × 25 mm specimens. The fracture toughness (the critical stress intensity factor, K IC ) of the composites was also evaluated using a three-point single edge notch beam (SENB) bending technique. Statistical analysis of the data was performed with ANOVA and the Tukey's post-hoc test. The fiber-resin interface and the fracture surface were investigated using SEM. Results The change in the surface mechanical properties and chemistry of the corona treated UHMWPE fibers were monitored. The fibers exposed to corona for 5 s showed higher surface nanohardness. In the FRCs, the specimens reinforced with 5 s corona treated silanized fibers showed higher mechanical properties (flexural modulus, flexural strength, and fracture toughness), SEM images revealed a better adhesion between the resin and fibers after 5 s fiber corona treatment and silanization. Significance Corona and silane treatment of UHMWPE fibers provide dental FRCs with improved mechanical properties. [ABSTRACT FROM AUTHOR]

Advancing and receding contact angle measurements on polymer surfaces can be performed using a number of different methods. Ballistic deposition is a new method for both rapidly and accurately measuring the receding contact angle of water. In the ballistic deposition method, a pulsed stream of 0.15-μL water droplets is impinged upon a surface. The water spreads across the surface and then coalesces into a single 1.8-μL drop. High-speed video imaging shows that, on most surfaces, the water retracts from previously wetted material, thereby forming receding contact angles that agree with the receding angles measured by the Wilhelmy plate technique. The ballistic deposition method measures the receding angle within one second after the water first contacts the surface. This rapid measurement enables the investigation of polymer surface properties that are not easily probed by other wettability measurement methods. For example, meaningful contact angles of water can be obtained on the water-soluble low-molecular-weight oxidized materials (LMWOM) formed by the corona and flame treatment of polypropylene (PP) films. Use of the ballistic deposition method allows for a characterization of the wetting properties and an estimation of the surface energy components of LMWOM itself. Both corona- and flame-generated LMWOM have significant contact angle hysteresis, almost all of which is accounted for by the non-dispersive (polar) component of the surface rather than by the dispersive component. Surface heterogeneity is thus associated primarily with the oxidized functionalities added to the PP by the corona and flame treatments. [ABSTRACT FROM AUTHOR]

This research aims to create the durable self-cleaning property on cotton fabric using nano titanium dioxide and corona treatment as a dry and environmentally friendly process. In this regard, cotton fabrics were investigated under corona treatment with intensities of 2 and 3 A for 1, 3, and 5 min of irradiation. The treated samples with 0.1, 0.5, 1, and 1.5 on weight of bath percent were cured by nano titanium dioxide to obtain the highest self-cleaning property. The treated cotton fabrics, which were stained with direct green 6, were exposed to 20 and 400 W of UV radiation and their self-cleaning property was examined, and the results were reported. In addition, using corona treatment helped to stabilize the nano titanium dioxide on the cotton fabric surface even after 50 washing cycles. Through SEM images, Thermo Gravimetric Analysis plots, and XRD patterns, the presence of nano titanium dioxide on the surface of the treated cotton samples after washing was verified. Also, the tensile strengths of TiO2-coated cotton fabrics were measured. [ABSTRACT FROM AUTHOR]