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42 results on '"Solař, Pavel"'

7. Insoluble Network Skeleton and Soluble Components of Nylon 6,6-Sputtered Nanoparticles: Insights from Liquid-State and Solid-State NMR Analysis.

Author

Šťastná, Julie, Škorvánková, Kateřina, Kuzminova, Anna, Hanuš, Jan, Hanyková, Lenka, Krakovský, Ivan, and Solař, Pavel

Subjects
NUCLEAR magnetic resonance spectroscopy, GEL permeation chromatography, NUCLEAR magnetic resonance, X-ray photoelectron spectroscopy, SCANNING electron microscopy, HEAT treatment
Abstract

In this study, we performed a detailed analysis of -sputtered-nylon 6,6 plasma polymer nanoparticles (NPs). Following a previous study using standard techniques such as X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy, we employed unconventional approaches, specifically solid- and liquid-state high-resolution nuclear magnetic resonance (NMR) spectroscopy, supplemented by gel permeation chromatography (GPC). Scanning electron microscopy (SEM) was also used to examine changes in the size of the NPs after contact with solvents and after heating. Our investigations revealed suspected strong binding and networking of the NPs, and a soluble monomer/oligomer phase was identified and characterised. This fraction is removable using solvent or heat treatment without significantly affecting the size of the NPs. Additionally, we suggested the chemical structure of this soluble phase. Our findings support the proposed rubber-like character of plasma polymer NPs and explain their strong tendency to reflect from substrates upon high-speed impact. [ABSTRACT FROM AUTHOR]

Published
2024
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8. Challenges in the deposition of plasma polymer nanoparticles using gas aggregation source: Rebounding upon impact and how to land them on a substrate.

Author

Solař, Pavel, Škorvánková, Kateřina, Kuzminova, Anna, and Kylián, Ondřej

Subjects
*PLASMA deposition, *METAL nanoparticles, *NANOPARTICLES, *POLYMERS, *METALLIC oxides
Abstract

Plasma polymer nanoparticles (pp‐NPs) are relatively easy to produce by plasma‐based gas aggregation sources. However, as experimentally evidenced in this study for the case of C:H:N:O pp‐NPs, pp‐NPs are unlike metal/metal oxide nanoparticles prone to reflection from the substrate if they hit it with too high a speed. This may result in little or no deposition rate even though the nanoparticle beam is very intense. As is shown, the deposition of pp‐NPs can be promoted either by the adjustment of their speed before they reach the substrate or by a proper selection of a substrate. Concerning the latter, enhanced capturing of pp‐NPs was observed on structured or liquid substrates. [ABSTRACT FROM AUTHOR]

Published
2023
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14. Calorimetric investigations in a gas aggregation source.

Author

Gauter, Sven, Haase, Fabian, Solař, Pavel, Kylián, Ondřej, Kúš, Peter, Choukourov, Andrei, Biederman, Hynek, and Kersten, Holger

Subjects
FLUX (Energy), THERMAL probe surveys, MAGNETRON sputtering, ENERGY conversion, ARGON
Abstract

A gas aggregation source based on DC magnetron sputtering was investigated using a passive thermal probe and supplementary diagnostics (Langmuir probe and quartz crystal microbalance). Parameter variations of pressure, axial distance, and magnetron current have been performed for three different targets (pure Cu, pure W, composite Cu/W) in argon discharge. The measurements showed the energy flux to be significantly higher for the case of the pure tungsten and the composite target compared to the copper target, which is likely a result of the strongly increased amount of neutrals being reflected from the heavier targets. Furthermore, gas rarefaction by the sputtered atoms was found to be essential for the understanding of the observed energy flux and that the dominant contributors to the energy flux in the higher pressure regime are comparable to those observed in the conventional lower pressure regime. Selected deposited films have been investigated ex-situ by scanning electron microscopy, which allowed us to gain insight into the nanoparticle formation in relation to the observed energy conversion. [ABSTRACT FROM AUTHOR]

Published
2018
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15. Polyester urethane (PLA/PEG) polymer based films prepared by plasma assisted vapour thermal deposition

Author

Kučerová, Liliana, Kolářová Rašková, Zuzana, Kousal, Jaroslav, Krtouš, Zdeněk, Solař, Pavel, Sedlaříková, Jana, Lehocký, Marián, Kučerová, Liliana, Kolářová Rašková, Zuzana, Kousal, Jaroslav, Krtouš, Zdeněk, Solař, Pavel, Sedlaříková, Jana, and Lehocký, Marián

Abstract

Polyester urethane polymer was synthesized as linked biocompatible poly (lactide)/poly (ethylene oxide) polymers. The bulk polymer was subsequently used as precursor material for plasma assisted vapour thermal deposition of thin plasma polymer films under varying RF discharge power. The effect of plasma polymerization on the final physico-chemical characteristics was investigated. The chemical analysis of the films was performed using X-ray photoelectron spectroscopy and infrared spectroscopy. Structural analysis of plasma polymer thin film revealed the similar molecular structure as in case of precursor since PEU-characteristic bonds were preserved after the plasma polymerization. Surface properties analysed by a contact angle measurement revealed an increase of wettability in the samples prepared at higher RF power. At the same time a surface energy evaluated according to acid-base model decreased. The results indicate that plasma polymer films properties could be tuned depending on applied deposition conditions. © NANOCON 2019.All right reserved.

Published
2020

19. Nucleation and Growth of Magnetron‐Sputtered Ag Nanoparticles as Witnessed by Time‐Resolved Small Angle X‐Ray Scattering

Author

Shelemin, Artem, primary, Pleskunov, Pavel, additional, Kousal, Jaroslav, additional, Drewes, Jonas, additional, Hanuš, Jan, additional, Ali‐Ogly, Suren, additional, Nikitin, Daniil, additional, Solař, Pavel, additional, Kratochvíl, Jiří, additional, Vaidulych, Mykhailo, additional, Schwartzkopf, Matthias, additional, Kylián, Ondřej, additional, Polonskyi, Oleksandr, additional, Strunskus, Thomas, additional, Faupel, Franz, additional, Roth, Stephan V., additional, Biederman, Hynek, additional, and Choukourov, Andrei, additional

Published
2019
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21. Effect of magnetic field on the formation of Cu nanoparticles during magnetron sputtering in the gas aggregation cluster source

Author

Vaidulych, Mykhailo, primary, Hanuš, Jan, additional, Kousal, Jaroslav, additional, Kadlec, Stanislav, additional, Marek, Aleš, additional, Khalakhan, Ivan, additional, Shelemin, Artem, additional, Solař, Pavel, additional, Choukourov, Andrei, additional, Kylián, Ondřej, additional, and Biederman, Hynek, additional

Published
2019
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22. Magnetron Sputtering of Polymeric Targets: From Thin Films to Heterogeneous Metal/Plasma Polymer Nanoparticles

Author

Kylián, Ondřej, primary, Shelemin, Artem, additional, Solař, Pavel, additional, Pleskunov, Pavel, additional, Nikitin, Daniil, additional, Kuzminova, Anna, additional, Štefaníková, Radka, additional, Kúš, Peter, additional, Cieslar, Miroslav, additional, Hanuš, Jan, additional, Choukourov, Andrei, additional, and Biederman, Hynek, additional

Published
2019
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25. Plasma polymers with controlled degradation behaviour

Author

Kousal, Jaroslav, Kolářová Rašková, Zuzana, Sedlaříková, Jana, Stloukal, Petr, Solař, Pavel, Krtouš, Zdeněk, Choukourov, Andrei, Sedlařík, Vladimír, Lehocký, Marián, Kousal, Jaroslav, Kolářová Rašková, Zuzana, Sedlaříková, Jana, Stloukal, Petr, Solař, Pavel, Krtouš, Zdeněk, Choukourov, Andrei, Sedlařík, Vladimír, and Lehocký, Marián

Abstract

Classical “wet“chemistry methods can produce polymers with well-defined molecular structure, but many types of polymers are difficult to prepare with significant degree of crosslinking without residues of the crosslinking agent. On the other hand, plasma polymers usually have very high degree of crosslinking but nearly random molecular structure. Plasma assisted vapour thermal deposition combines both methods. Classical polymers are heated in a crucible at low pressure and the released oligomeric fragments of the polymer chain are repolymerized in a glow discharge into a thin film. The number of well-preserved monomeric units between the crosslinks can be tuned e.g. from units to tens. Poly-lactic acid (PLA) belongs to a special class of biodegradable polymeric materials. In this work, plasma assisted vapour thermal deposition was utilized to prepare PLA plasma polymers. Molar weights and chemical composition of the “precursor” polymer and of the thin films have been characterized. As the measure of degradability, behaviour of the polymers during hydrolysis has been studied using spectroscopic ellipsometry and liquid chromatography. Possibility to prepare plasma polymer films with controlled degradability was demonstrated. © 2018 TANGER Ltd. All Rights Reserved.

Published
2018

26. Nucleation and Growth of Magnetron‐Sputtered Ag Nanoparticles as Witnessed by Time‐Resolved Small Angle X‐Ray Scattering.

Author

Shelemin, Artem, Pleskunov, Pavel, Kousal, Jaroslav, Drewes, Jonas, Hanuš, Jan, Ali‐Ogly, Suren, Nikitin, Daniil, Solař, Pavel, Kratochvíl, Jiří, Vaidulych, Mykhailo, Schwartzkopf, Matthias, Kylián, Ondřej, Polonskyi, Oleksandr, Strunskus, Thomas, Faupel, Franz, Roth, Stephan V., Biederman, Hynek, and Choukourov, Andrei

Subjects
SMALL-angle scattering, X-ray scattering, SMALL-angle X-ray scattering, DISCONTINUOUS precipitation, TOROIDAL plasma, MAGNETRON sputtering, NANOPARTICLES
Abstract

Kinetic aspects of the synthesis of Ag nanoparticles (NPs) by magnetron sputtering are studied by in situ and time‐resolved small angle X‐ray scattering (SAXS). Part of the NPs are found to become confined within a capture zone at 1–10 mm from the surface of the target and circumscribed by the plasma ring. Three regimes of the NP growth are identified: 1) early growth at which the average NP diameter rapidly increases to 90 nm; 2) cycling instabilities at which the SAXS signal periodically fluctuates either due to expelling of large NPs from the capture zone or due to the axial rotation of the NP cloud; and 3) steady‐state synthesis at which stable synthesis of the NPs is achieved. The NP confinement within the capture zone is driven by the balance of forces, the electrostatic force being dominant. On reaching the critical size, large NPs acquire an excessive charge and become expelled from the capture zone via the electrostatic interactions. As a result, significant NP deposits are formed on the inner walls of the aggregation chamber as well as in the central area of the target. [ABSTRACT FROM AUTHOR]

Published
2020
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27. Magnetron-sputtered copper nanoparticles: lost in gas aggregation and found by in situ X-ray scattering

Author

Kousal, Jaroslav, primary, Shelemin, Artem, additional, Schwartzkopf, Matthias, additional, Polonskyi, Oleksandr, additional, Hanuš, Jan, additional, Solař, Pavel, additional, Vaidulych, Mykhailo, additional, Nikitin, Daniil, additional, Pleskunov, Pavel, additional, Krtouš, Zdeněk, additional, Strunskus, Thomas, additional, Faupel, Franz, additional, Roth, Stephan V., additional, Biederman, Hynek, additional, and Choukourov, Andrei, additional

Published
2018
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28. Advances and challenges in the field of plasma polymer nanoparticles

Author

Choukourov, Andrei, primary, Pleskunov, Pavel, additional, Nikitin, Daniil, additional, Titov, Valerii, additional, Shelemin, Artem, additional, Vaidulych, Mykhailo, additional, Kuzminova, Anna, additional, Solař, Pavel, additional, Hanuš, Jan, additional, Kousal, Jaroslav, additional, Kylián, Ondřej, additional, Slavínská, Danka, additional, and Biederman, Hynek, additional

Published
2017
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32. Preparation of nanostructured and nanocomposite thin films with plasma polymer matrix

Author

Solař, Pavel, Biederman, Hynek, Novák, Rudolf, and Tichý, Milan

Subjects
plazmový polymer, kompozitní tenká vrstva, depozice pod úhlem, plasma polymer, Nanoparticles, composite thin film, Glancing Angle Deposition, Nanočástice
Abstract

Title: Preparation of nanostructured and nanocomposite thin films with plasma polymer matrix Author: Pavel Solař Department: Department of Macromolecular Physics, MFF, UK Supervisor of the doctoral thesis Prof. RNDr. Hynek Biederman, DrSc., Department of Macromolecular Physics, Faculty of Mathematics and Physics, Charles University in Prague Abstract: This thesis is devoted to study of nanostructured thin films implementing metal and plasma polymer particles and columns. Process of formation of particles from various materials has been studied. The particles size, shape and chemical composition has been characterized relative to the deposition conditions. Transport of metal and plasma polymer particles inside the particle source and from the particle source to substrate has been investigated. The particles were used in composite films especially to produce films with controlled roughness e.g. for investigation of influence of roughness on adhesion of cells. Preparation of columnar films by Glancing Angle Deposition has been studied and the particles have been used as seeds for the columnar growth. Keywords: Nanoparticles, Glancing Angle Deposition, plasma polymer, composite thin film

Published
2014

33. Nanostructured films based on plasma polymers

Author

Solař, Pavel, Shukurov, Andrey, and Vyskočil, Jiří

Subjects
low pressure magnetron, nízkotlaký magnetron, nanostructured thin films, šikmá depozice, nanostrukturované tenké vrstvy, tilted deposition
Abstract

In this thesis we have studied growth and properties of thin films prepared by tilted deposition using sputtering. The construction of low pressure magnetron is presented. The influence of deposition conditions on formation of columnar structure using scanning electron microscope was studied. Formation of columnar structures of metals, composites metal-plasma polymer and plasma polymer is described. The influence of deposition conditions on surface roughness obtained by AFM is discussed. Chemical structure of composite and plasma polymer films has been determined using XPS and infrared spectroscopy.

Published
2012

35. Back Cover: Plasma Process. Polym. 5∕2015

Author

Solař, Pavel, primary, Kylián, Ondřej, additional, Petr, Martin, additional, Hanuš, Jan, additional, Choukourov, Andrei, additional, Slavínská, Danka, additional, and Biederman, Hynek, additional

Published
2015
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39. Morphology of Titanium Nanocluster Films Prepared by Gas Aggregation Cluster Source

Author

Drábik, Martin, primary, Choukourov, Andrei, additional, Artemenko, Anna, additional, Kousal, Jaroslav, additional, Polonskyi, Oleksandr, additional, Solař, Pavel, additional, Kylián, Ondřej, additional, Matoušek, Jindřich, additional, Pešička, Josef, additional, Matolínová, Iva, additional, Slavínská, Danka, additional, and Biederman, Hynek, additional

Published
2011
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41. Influence of non-equilibrium plasma on seeds

Author

Červenková, Veronika, Kylián, Ondřej, and Solař, Pavel

Subjects
nerovnovážné plazma|plazmové zemědělství, non-equilibrium plasma|plasma agriculture
Abstract

Agriculture was, is and will always be one of the most important economic sectors owing to its primary purpose: the global food security. Forming the base pillar of the so- ciety's system, it is the privilege of nations to make their products accessible to everyone, regardless of the environmental or economical conditions. The employment of the newest technologies in order to secure its regulation gave rise to a brand new field of science - plasma agriculture. Plasma agriculture examines the use of non-thermal plasma on natural sources with diverse objectives. Soil rehabilitation, microbial food decontamination or insecticide acti- vities are not the only examples. In this thesis we shall devote to the DBD air plasma application on the Pumpkin seeds (sort Small Sugar) in order to improve its germination. After verifying the selected plasma source impact on eight polymer foils the main focus was given to the seeds. It was found that the plasma treatment induces changes in the chemical composition and water droplet drying dynamics that in turn result in dramatic increase of surface wettability. These changes must not have been accompanied by the burning; otherwise the treatment led to a radical disruption of seeds' morphology and to failure of the essential - enhancement of the germination rate. 1

Published
2021

42. Study of velocities of nanoparticles produced by means gas aggregation source

Author

Škorvánková, Kateřina, Solař, Pavel, and Nikitin, Daniil

Subjects
nanoparticle velocity|gas aggregation source|magnetron sputtering|plasma, rychlost nanočástic|plynový agregační zdroj|magnetronové rozprašování|plazma
Abstract

A mechanical time-of-flight filter designed for measuring velocities of nanoparticles produced by gas aggregation source has been developed. The emphasis is placed on the resolution and accuracy maximization as well as on simplicity of use. It is shown that the experimentally measured data (influenced by the design of the filtr) may be converted to the real velocity distribution and a method of conversion is presented. Subsequently, the filter is used to measure velocities of nanoparticles produced under various experimental conditions and the dependence of the velocity on given conditions is shown. Furthermore, a sample for every experimental setup has been prepared for SEM analysis to determine size distribution of the nanoparticles. Finally, the size dependence of velocity is illustrated.

Published
2021

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