National Repository of Grey Literature 5 records found  Search took 0.00 seconds. 
Comparative study on functionalization of NCD films with amine groups
Artemenko, Anna ; Kozak, Halyna ; Stuchlík, Jiří ; Biederman, H. ; Kromka, Alexander
Two plasma-based processes for functionalization of oxygen or hydrogen terminated NCD surfaces with amino groups were compared. The first process was based on deposition of thin (8 nm) amine containing plasma polymer by RF magnetron sputtering of Nylon target in Ar/N-2 working gas mixture. RF plasma treatment in NH3 for 10 minutes was used in the second process. The properties of NCD films before and after amination were characterized by scanning electron microscopy (SEM), wettability measurements, spectral ellipsometry, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and current-voltage (I-V) measurements. The presence of nitrogen (and thus amino groups) on the surface was confirmed by XPS measurements in both cases. The obtained results indicated that NCD surface functionalization from amine containing plasma polymer by RF magnetron sputtering is an alternative technological solution for successful functionalization of diamond surfaces for biosensor applications.
XPS analysis of plasma polymers and nanocomposite films without breaking vacuum
Artemenko, Anna ; Biederman, Hynek (advisor) ; Čech, Vladimír (referee) ; Novák, Stanislav (referee)
Title: XPS analysis of plasma polymers and nanocomposite films without breaking vacuum Author: Anna Artemenko Institute: Charles University in Prague, Department of Macromolecular Physics Supervisor of the doctoral thesis: Prof. RNDr. Hynek Biederman, DrSc., Charles University in Prague, Department of Macromolecular Physics. Abstract: Plasma polymers and metal/ plasma polymer nanocomposites have been widely used for various biomedical proposes. Naturally, surface properties of the coatings such as high wettability, stability on the open air and in aqueous media, resistance towards different sterilization processes and cells adhesion are required for bioapplications. This thesis is mainly dedicated to the investigation of chemical composition of deposited coatings using XPS analysis. Nylon-like plasma polymer, PEO-like coatings, fluorocarbon plasma polymer (PTFE) films and Au/PEO-like, Ag/C:H, Al/C:H nanocomposites were chosen as the subject material. In addition, results of XPS measurements were used for the computer simulation for calculation of filling factor of metal/ plasma polymer nanocomposites. These results were in a good agreement with experimental data. Keywords: plasma polymer, nanocomposite, XPS analysis, bioapplication, simulation.
Growth of Escherichia coli on nanocrystalline diamond
Jurková, Blanka ; Kozak, Halyna ; Artemenko, Anna ; Ukraintsev, Egor ; Beranová, J. ; Konopásek, I. ; Kromka, Alexander
In this contribution, we compared the attachment of gram-negative model bacterium Escherichia coli to\nuncoated glass and glass coated by hydrogenated and oxidized NCD films. For attachment experiments,\ncontinuous cultivation in commercially available CDC Bioreactor was used. Antibacterial tests indicated\nhigher attachment of gram-negative model bacterium Escherichia coli to NCD surface compared to uncoated\nglass. We assign this effect to higher roughness of NCD surface compared to glass. Bacterial cells preferred\nthe hydrophobic surface of hydrogenated NCD surface to hydrophilic oxidized NCD for their attachment.
In situ XPS characterization of diamond films after AR.sup.+./sup. cluster ion beam sputtering
Artemenko, Anna ; Babchenko, Oleg ; Kozak, Halyna ; Ukraintsev, Egor ; Ižák, Tibor ; Romanyuk, Olexandr ; Potocký, Štěpán ; Kromka, Alexander
In this work, in situ XPS analysis of chemical composition of H- and O-terminated nano- and microcrystalline diamond (NCD and MCD) films before and after their sputtering by the Ar+ cluster ion beam was investigated. Scanning electron microscopy confirmed sputtering of all diamond surfaces with a rate about 0.5 nm/min. Raman spectroscopy and XPS revealed surface graphitization of diamond surface induced by sputtering. Moreover, XPS data showed the presence of about 0.7 % of Ar atoms on the investigated diamond surface after 66 min of sputtering. Also, oxygen residuals were still presented on the H-NCD surface after 66 min of sputtering. In contrast, no oxygen was found on the H-MCD surface just after 2 min of sputtering. Surface composition is discussed in respect to the diamond films growth parameters and surface structure.
Comparativ study on functionalization of NCD films with amine groups
Artemenko, Anna ; Kozak, Halyna ; Stuchlík, Jiří ; Biederman, H. ; Kromka, Alexander
Nanocrystalline diamond (NCD) films are considered as highly attractive material for biosensing due to its unique semiconducting properties. This can be achieved by modification of NCD films surface on molecular level. Typically chemical immobilization of biomoleculs requires the presence of active functional groups on the diamond surface. This was achieved by attachment of -NH2 functional groups on the surface of H- or O-terminated NCD surface via two plasma-based processes. The first process, deposition of thin amine containing polymer by RF magnetron sputtering of Nylon target in Ar/N2 gas mixture. The second process employs RF plasma treatment in NH3 for 10 minutes. Chemical derivatization (CD) XPS analysis revealed that polymeric coating exhibits a higher amount of amino groups than the diamond surface treated in NH3 RF plasma. Results of I-V measurements showed that surface conductivity of H-terminated NCD films was preserved only after the RF sputtering.

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