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1. Different configurations of transferred atmospheric pressure plasma jet and their application to polymer treatment

Author

Nascimento, Fellype do, Kostov, Konstantin Georgiev, Quade, Antje, and Canesqui, Mara Adriana

Subjects
Physics - Plasma Physics
Abstract

The employment of atmospheric pressure plasma jets (APPJs) in a large sort of applications is limited by the adversities related to the size of the treated area and the difficulty to reach the target. The use of devices that employ long tubes in their structure has contributed significantly to overcome these challenges. In this work, a comparison between two different plasma systems employing the jet transfer technique is presented. The main difference between the two devices is how the long plastic tube was assembled. The first one uses a copper wire placed inside a long plastic tube. The other device has a metallic mesh installed in a concentric arrangement between two coaxial plastic tubes. As a result, the two APPJ systems exhibit different properties, with the wire assembly being more powerful, also presenting higher values for the electrical current and rotational temperature when compared to the mesh mounting. X-ray photoelectron spectroscopy (XPS) demonstrates that both configurations were capable of inserting O-containing functional groups on the polypropylene (PP) surface. However, the transferred plasma jet with wire assembly was able to add more functional groups on the PP surface. The results from XPS analysis were corroborated with water contact angle measurements (WCA), being that lower WCA values were obtained when the PP surface presented higher amounts of O-containing groups. Surface morphology evaluation showed that the plasma treatment tends to slightly increase the surface roughness of the PP samples with both wire and mesh configurations. Furthermore, the findings in this work suggest that the APPJ with wire configuration is more appropriate for material treatments, while the transferred jet with mesh arrangement tends to present lower electrical current values which makes it more suitable for biological applications., Comment: 21 pages, 17 figures,3 tables

Published
2022
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5. Proposing an Affordable Plasma Device for Polymer Surface Modification and Microbial Inactivation.

Author

Chiappim, William, Kodaira, Felipe Vicente de Paula, Castro, Gisele Fátima Soares de, Silva, Diego Morais da, Tavares, Thayna Fernandes, Almeida, Ana Carla de Paula Leite, Leal, Bruno Henrique Silva, Quade, Antje, Koga-Ito, Cristiane Yumi, and Kostov, Konstantin Georgiev

Subjects
COLD atmospheric plasmas, PLASMA devices, MICROBIAL inactivation, STAPHYLOCOCCUS aureus, POWER resources
Abstract

This study proposes an affordable plasma device that utilizes a parallel-plate dielectric barrier discharge geometry with a metallic mesh electrode, featuring a straightforward 3D-printed design. Powered by a high-voltage supply adapted from a cosmetic plasma device, it operates on atmospheric air, eliminating the need for gas flux. Surface modification of polyethylene treated with this device was characterized and showed that the elemental composition after 15 min of plasma treatment decreased the amount of C to ~80 at% due to the insertion of O (~15 at%). Tested against Candida albicans and Staphylococcus aureus, the device achieved a reduction of over 99% in microbial load with exposure times ranging from 1 to 10 min. Simultaneously, the Vero cell viability remained consistently high, namely between 91% and 96% across exposure times. These results highlight this device's potential for the surface modification of materials and various infection-related applications, boasting affordability and facilitating effective antimicrobial interventions. [ABSTRACT FROM AUTHOR]

Published
2024
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6. Energetic characterization during plasma electrolytic polishing of cemented tungsten carbide.

Author

An, Sehoon, Hansen, Luka, Wolff, Thorben, Foest, Rüdiger, Fröhlich, Maik, Quade, Antje, Stankov, Marjan, and Kersten, Holger

Subjects
ELECTROLYTIC polishing, TUNGSTEN carbide, X-ray photoelectron spectroscopy
Abstract

Electrical and thermal measurements were conducted during the plasma electrolytic polishing (PEP) of cemented tungsten carbide (WC-Co) materials to characterize energetic aspects of the process in relation to the temporal development of the gaseous layer near the workpiece. The power transferred to the workpiece is determined using a calorimetric probe and employing the time derivative of the temperature curve. It shows distinct heating phases due to the generation of the gaseous layer. At the beginning of the process, a typical power of 367 ± 17 W is transferred to the workpiece of a surface area of 14 cm2. At longer process times, a stabilized gaseous layer limits the power transferred to the workpiece to 183 ± 3 W. In an attempt to describe the heat transferred to the electrolyte, the electrolyte temperature was measured using a thermocouple situated 15 mm away from the workpiece. The local electrolyte temperature increases from 70 to 81 °C for an immersion depth of 20 mm. Moreover, the spatiotemporal development of the electrolyte temperature was obtained by 2D-hydrodynamic modeling using COMSOL Multiphysics®. The modeling results for the local temporal temperature development are in excellent agreement with the experimental values when the turbulent model is applied up to t = 65 s. Afterward, the laminar model leads to a better agreement. Furthermore, line scan x-ray photoelectron spectroscopy revealed that aliphatic carbon was preferentially removed. Only a slight compositional gradient in the vertical direction after the PEP process was observed. [ABSTRACT FROM AUTHOR]

Published
2023
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8. Self-supported Pt–CoO networks combining high specific activity with high surface area for oxygen reduction

Author

Sievers, Gustav W., Jensen, Anders W., Quinson, Jonathan, Zana, Alessandro, Bizzotto, Francesco, Oezaslan, Mehtap, Dworzak, Alexandra, Kirkensgaard, Jacob J. K., Smitshuysen, Thomas E. L., Kadkhodazadeh, Shima, Juelsholt, Mikkel, Jensen, Kirsten M. Ø., Anklam, Kirsten, Wan, Hao, Schäfer, Jan, Čépe, Klára, Escudero-Escribano, María, Rossmeisl, Jan, Quade, Antje, Brüser, Volker, and Arenz, Matthias

Published
2021
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10. Using a dual plasma process to produce cobalt--polypyrrole catalysts for the oxygen reduction reaction in fuel cells -- part II: analysing the chemical structure of the films

Author

Walter, Christian, Kummer, Kurt, Vyalikh, Denis, Brüser, Volker, Quade, Antje, and Weltmann, Klaus-Dieter

Subjects
Condensed Matter - Materials Science, Physics - Chemical Physics, Physics - Plasma Physics
Abstract

The chemical structure of cobalt--polypyrrole -- produced by a dual plasma process -- is analysed by means of X-ray photoelectron spectroscopy (XPS), near edge X-ray absorption spectroscopy (NEXAFS), X-ray diffraction (XRD), energy-dispersive X-Ray spectroscopy (EDX) and extended x-ray absorption spectroscopy (EXAFS).It is shown that only nanoparticles of a size of 3\,nm with the low temperature crystal structure of cobalt are present within the compound. Besides that, cobalt--nitrogen and carbon--oxygen structures are observed. Furthermore, more and more cobalt--nitrogen structures are produced when increasing the magnetron power. Linking the information on the chemical structure to the results about the catalytic activity of the films -- which are presented in part I of this contribution -- it is concluded that the cobalt--nitrogen structures are the probable catalytically active sites. The cobalt--nitrogen bond length is calculated as 2.09\,\AA\ and the carbon--nitrogen bond length as 1.38\,\AA.

Published
2012
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11. Using a dual plasma process to produce cobalt--polypyrrole catalysts for the oxygen reduction reaction in fuel cells -- part I: characterisation of the catalytic activity and surface structure

Author

Walter, Christian, Kummer, Kurt, Vyalikh, Denis, Brüser, Volker, Quade, Antje, and Weltmann, Klaus-Dieter

Subjects
Physics - Chemical Physics, Condensed Matter - Materials Science, Physics - Plasma Physics
Abstract

A new dual plasma coating process to produce platinum-free catalysts for the oxygen reduction reaction in a fuel cell is introduced. The catalysts thus produced were analysed with various methods. Electrochemical characterisation was carried out by cyclic voltammetry, rotating ring- and rotating ring-disk electrode. The surface porosity of the different catalysts thus obtained was characterised with the nitrogen gas adsorption technique and scanning electron microscopy was used to determine the growth mechanisms of the films. It is shown that catalytically active compounds can be produced with this dual plasma process. Furthermore, the catalytic activity can be varied significantly by changing the plasma process parameters. The amount of H$_2$O$_2$ produced was calculated and shows that a 2 electron mechanism is predominant. The plasma coating mechanism does not significantly change the surface BET area and pore size distribution of the carbon support used. Furthermore, scanning electron microscopy pictures of the produced films are presented and show the preference of columnar growth mechanisms. By using different carbons as the support it is shown that there is a strong dependence of the catalytic activity that is probably related to the chemical properties of the carbon.

Published
2012
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15. Self-Activation of Inorganic-Organic Hybrids Derived through Continuous Synthesis of Polyoxomolybdate and para-Phenylenediamine Enables Very High Lithium-Ion Storage Capacity

Author

Mohamed, Mana Abdirahman, Arnold, Stefanie, Janka, Oliver, Quade, Antje, Presser, Volker, and Kickelbick, Guido

Subjects
lithium-ion batteries, polyoxometalates, inorganic-organic hybrid materials, continuous synthesis, electrodes
Abstract

Inorganic-organic hybrid materials with redox-active components were prepared by an aqueous precipitation reaction of ammonium heptamolybdate (AHM) with para-phenylenediamine (PPD). A scalable and low-energy continuous wet chemical synthesis process, known as the microjet process, was used to prepare particles with large surface area in the submicrometer range with high purity and reproducibility on a large scale. Two different crystalline hybrid products were formed depending on the ratio of molybdate to organic ligand and pH. A ratio of para-phenylenediamine to ammonium heptamolybdate from 1 : 1 to 5 : 1 resulted in the compound [C6H10N2]2[Mo8O26] ⋅ 6 H2O, while higher PPD ratios from 9 : 1 to 30 : 1 yielded a composition of [C6H9N2]4[NH4]2[Mo7O24] ⋅ 3 H2O. The electrochemical behavior of the two products was tested in a battery cell environment. Only the second of the two hybrid materials showed an exceptionally high capacity of 1084 mAh g−1 at 100 mA g−1 after 150 cycles. The maximum capacity was reached after an induction phase, which can be explained by a combination of a conversion reaction with lithium to Li2MoO4 and an additional in situ polymerization of PPD. The final hybrid material is a promising material for lithium-ion battery (LIB) applications.

Published
2023
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17. Gas diffusion electrode activity measurements of iridium-based self-supported catalysts produced by alternated physical vapour deposition

Author

Jiménez, Pablo Collantes, Sievers, Gustav, Quade, Antje, Brüser, Volker, Pittkowski, Rebecca Katharina, Arenz, Matthias, Jiménez, Pablo Collantes, Sievers, Gustav, Quade, Antje, Brüser, Volker, Pittkowski, Rebecca Katharina, and Arenz, Matthias

Abstract

The scarce supply of Ir used to catalyze the sluggish oxygen evolution reaction in acidic water electrolysis calls for unconventional approaches to design more active catalysts with minimal resource usage for their commercial scaling. Industrial-ready production methods and laboratory scale tests that can reflect the catalyst behaviour realistically need to be included in this process. In this work, we benchmarked three series of self-supported Ir–Co catalysts with low Ir loading produced by physical vapour deposition under relevant current densities in a gas diffusion electrode setup. It was seen that after selective acid leaching of the Co, a nanoporous structure with a high electrochemically active surface area and a mixed oxide and metallic character was formed. Depending on the initial Co:Ir deposition ratio over ten times higher oxygen evolution mass activities could be reached as compared to a commercial, unsupported IrOx nanoparticle catalyst used as a benchmark in the same setup configuration. The presented integrative catalyst design and testing strategy will help to facilitate bridging the gap between research and application for the early introduction of next-generation catalysts for water splitting.

Published
2023

18. Continuous wet chemical synthesis of Mo(C,N,O)x as anode materials for Li-ion batteries.

Author

Abdirahman Mohamed, Mana, Arnold, Stefanie, Janka, Oliver, Quade, Antje, Schmauch, Jörg, Presser, Volker, and Kickelbick, Guido

Abstract

Molybdenum carbides, oxides, and mixed anionic carbide–nitride–oxides Mo(C,N,O)x are potential anode materials for lithium-ion batteries. Here we present the preparation of hybrid inorganic–organic precursors by a precipitation reaction of ammonium heptamolybdate ((NH4)6Mo7O24) with para-phenylenediamine in a continuous wet chemical process known as a microjet reactor. The mixing ratio of the two components has a crucial influence on the chemical composition of the obtained material. Pyrolysis of the precipitated precursor compounds preserved the size and morphology of the micro- to nanometer-sized starting materials. Changes in pyrolysis conditions such as temperature and time resulted in variations of the final compositions of the products, which consisted of mixtures of Mo(C,N,O)x, MoO2, Mo2C, Mo2N, and Mo. We optimized the reaction conditions to obtain carbide-rich phases. When evaluated as an anode material for application in lithium-ion battery half-cells, one of the optimized materials shows a remarkably high capacity of 933 mA h g−1 after 500 cycles. The maximum capacity is reached after an activation process caused by various conversion reactions with lithium. [ABSTRACT FROM AUTHOR]

Published
2023
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26. X-ray Ptychographic Imaging and Spectroscopic Studies of Plasma-Treated Plastic Films

Author

Ravandeh, Mehdi, primary, Mehrjoo, Masoud, additional, Kharitonov, Konstantin, additional, Schäfer, Jan, additional, Quade, Antje, additional, Honnorat, Bruno, additional, Ruiz-Lopez, Mabel, additional, Keitel, Barbara, additional, Kreis, Svea, additional, Pan, Rui, additional, Gang, Seung-gi, additional, Wende, Kristian, additional, and Plönjes, Elke, additional

Published
2022
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33. Different configurations of transferred atmospheric pressure plasma jet and their application to polymer treatment.

Author

do Nascimento, Fellype, Quade, Antje, Canesqui, Mara Adriana, and Kostov, Konstantin Georgiev

Subjects
*PLASMA jets, *ATMOSPHERIC pressure plasmas, *X-ray photoelectron spectroscopy, *CONTACT angle, *COPPER wire
Abstract

The employment of atmospheric pressure plasma jets (APPJs) in a large sort of applications is limited by the adversities related to the size of the treated area and the difficulty to reach the target. The use of devices that employ long tubes in their structure has contributed significantly to overcome these challenges. In this work, two different plasma systems employing the jet transfer technique are compared. The main difference between the two devices is how the long plastic tube was assembled. The first one uses a copper wire placed inside a long plastic tube. The other device has a metallic mesh installed in a concentric arrangement between two coaxial plastic tubes. As a result, the two APPJ systems exhibit different properties, with the wire assembly being more powerful, also presenting higher values for the electrical current and rotational temperature when compared to the mesh mounting. X‐ray photoelectron spectroscopy (XPS) demonstrates that both configurations were capable of inserting O‐containing functional groups on the polypropylene (PP) surface. However, the transferred plasma jet with wire assembly was able to add more functional groups on the PP surface. The results from XPS analysis were corroborated with water contact angle measurements (WCA), being that lower WCA values were obtained when the PP surface presented higher amounts of O‐containing groups. Furthermore, the results suggest that the APPJ with wire configuration is more appropriate for material treatments, while the transferred jet with mesh arrangement tends to present lower electrical current values, being more suitable for biological applications. [ABSTRACT FROM AUTHOR]

Published
2023
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39. HelixJet: An innovative plasma source for next-generation additive manufacturing (3D printing)

Author

Sch��fer, Jan, Quade, Antje, Abrams, Kerry J., Sigeneger, Florian, Becker, Markus M., Majewski, Candice, and Rodenburg, Cornelia

Subjects
polyamide, electron microscopy, plasma printing, additive manufacturing, thermography
Abstract

A novel plasma source (HelixJet) for use in additive manufacturing (AM)/3D printing is proposed. The HelixJet is a capacitively coupled radio frequency plasma with a double-helix electrode configuration that generates a surprisingly stable and homogeneous glow plasma at low flow rates of argon and its mixtures at atmospheric pressure. The HelixJet was tested on three polyamide powders usually used to produce parts by laser sintering, a powder-based AM process, to form local deposits. The chemical composition of such plasma-printed samples is compared with thermally produced and laser-sintered samples with respect to differences in morphology that result from the different thermal cycles on several length scales. Plasma prints exhibit unique features attributable to the nonequilibrium chemistry and to the high-speed heat exchange.

Published
2020
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44. Self-supported Pt–CoO networks combining high specific activity with high surface area for oxygen reduction

Author

Sievers, Gustav W., primary, Jensen, Anders W., additional, Quinson, Jonathan, additional, Zana, Alessandro, additional, Bizzotto, Francesco, additional, Oezaslan, Mehtap, additional, Dworzak, Alexandra, additional, Kirkensgaard, Jacob J. K., additional, Smitshuysen, Thomas E. L., additional, Kadkhodazadeh, Shima, additional, Juelsholt, Mikkel, additional, Jensen, Kirsten M. Ø., additional, Anklam, Kirsten, additional, Wan, Hao, additional, Schäfer, Jan, additional, Čépe, Klára, additional, Escudero-Escribano, María, additional, Rossmeisl, Jan, additional, Quade, Antje, additional, Brüser, Volker, additional, and Arenz, Matthias, additional

Published
2020
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47. Cover Picture: Plasma Process. Polym. 1/2020

Author

Schäfer, Jan, primary, Quade, Antje, additional, Abrams, Kerry J., additional, Sigeneger, Florian, additional, Becker, Markus M., additional, Majewski, Candice, additional, and Rodenburg, Cornelia, additional

Published
2020
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48. Ionic liquid-based synthesis of MXene

Author

Husmann, Samantha, primary, Budak, Öznil, additional, Shim, Hwirim, additional, Liang, Kun, additional, Aslan, Mesut, additional, Kruth, Angela, additional, Quade, Antje, additional, Naguib, Michael, additional, and Presser, Volker, additional

Published
2020
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