@article{GrytsenkoKsianzouKolomzarovetal.2021, author = {Grytsenko, Kostyantyn and Ksianzou, Viachaslau and Kolomzarov, Yurii and Lytvyn, Peter and Dietzel, Birgit and Schrader, Sigurd}, title = {Fluoropolymer Film Formation by Electron Activated Vacuum Deposition}, series = {Surfaces}, volume = {4}, journal = {Surfaces}, number = {1}, publisher = {MDPI}, issn = {2571-9637}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-13786}, pages = {66 -- 80}, year = {2021}, abstract = {Polytetrafluoroethylene (PTFE), polyhexafluoropropylene (PHFP) and polychlorotrifluoroethylene (PCTFE) were heated to their decomposition temperature in a high vacuum. The emitted fragments passed an electron cloud, condensed on a substrate and formed fluoropolymer film. Growth rate of PTFE and PHFP films increased up to a factor five in the presence of the electron cloud. Mass spectrometry revealed changes in the mass spectra of fragments generated by thermal decomposition only and formed under electron activation. The observed changes were different for each fluoropolymer. Infrared spectroscopy (IRS) showed that the structure of the films was close to the structure of the bulk polymers. Atomic force microscopy (AFM) has revealed different morphologies of PTFE, PHFP and PCTFE films, suggesting a Volmer-Weber growth mechanism for PTFE and PHFP but a Frank-van der Merwe one for PCTFE. All films were smooth at nanoscale and transparent from ultraviolet to near-infrared region. Additional radio frequency (RF) plasma ignited in the emitted fragments at a low pressure increased mechanical characteristics of the films without losing their optical transparency and smoothness.}, language = {en} } @article{DimitrievGrytsenkoTolmachevetal.2014, author = {Dimitriev, O. P. and Grytsenko, Kostyantyn and Tolmachev, O. I. and Slominskii, Yu L. and Kudinova, M. A. and Schrader, Sigurd}, title = {Effect of Concentration on Isomerization of Rhodanine Derivatives of Merocyanine Dyes in Polar Solvents}, series = {Advances in Physical Chemistry}, volume = {2014}, journal = {Advances in Physical Chemistry}, issn = {1687-7993}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-5931}, pages = {9}, year = {2014}, abstract = {Rhodanine derivatives of merocyanine dyes with residues of 1,3,3-trimethyl-3H-indole and 3-ethylbenzothiazoline have been found to possess two molecular forms in diluted solutions of polar solvents such as dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidinone. The first molecular form was observed to prevail at low concentrations of the dyes, normally up to 10-5 M. The second one prevails at higher concentrations and is displayed through a new band in the electronic absorption spectrum, which is red-shifted with respect to the absorption band of the first form. No similar effect was found for these dyes by use of nonpolar solvents or upon alkyl-substitution of the molecules at nitrogen atom in the rhodanine moiety. We assign the above two forms to different molecular isomers and the analogous spectral changes were shown to take place by light or heat influence which correspond to a typical isomerization effect for the related merocyanine dyes. It is discussed that the isomer transformation is facilitated by the increased mobility of the proton bonded to the nitrogen atom of the rhodanine moiety in the polar environment and the increased amount of dye-dye collisions.}, language = {en} } @article{GrytsenkoLozovskiStrilchuketal.2012, author = {Grytsenko, Kostyantyn and Lozovski, Valeri and Strilchuk, Galyna and Schrader, Sigurd}, title = {Evaluation of the Mechanism of the Gold Cluster Growth during Heating of the Composite Gold-Polytetrafluoroethylene Thin Film}, series = {Nanomaterials}, volume = {2}, journal = {Nanomaterials}, number = {4}, issn = {2079-4991}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-6387}, pages = {366 -- 378}, year = {2012}, abstract = {Nanocomposite films consisting of gold inclusions in the polytetrafluoroethylene (PTFE) matrix were obtained by thermal vacuum deposition. Annealing of the obtained films with different temperatures was used to measure varying of film morphologies. The dependence of optical properties of the films on their morphology was studied. It was established that absorption and profile of the nanocomposite film obtained by thermal vacuum deposition can be changed with annealing owing to the fact that different annealing temperatures lead to different average particle sizes. A method to calculate the optical properties of nanocomposite thin films with inclusions of different sizes was proposed. Thus, comparison of experimental optical spectra with the spectra obtained during the simulation enables estimating average sizes of inclusions. The calculations give the possibility of understanding morphological changes in the structures.}, language = {en} } @article{SopinskyyGrytsenkoVillringeretal.2023, author = {Sopinskyy, Mykola and Grytsenko, Kostyantyn and Villringer, Claus and Kolomzarov, Yurii and Schrader, Sigurd}, title = {Determination of scattering and Urbach absorption contributions to the light extinction in PTFE films by using graphical representation technique and numerical solution of the inverse problem}, series = {Semiconductor Physics, Quantum Electronics \& Optoelectronics}, volume = {26}, journal = {Semiconductor Physics, Quantum Electronics \& Optoelectronics}, number = {3}, publisher = {National Academy of Sciences of Ukraine. Institute for Semiconductor Physics}, address = {Kyiv}, issn = {1605-6582}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-18035}, pages = {303 -- 314}, year = {2023}, abstract = {Ellipsometrically obtained spectral dependences of ordinary αxy and extra-ordinary αz extinction/attenuation coefficients within the spectral range λ = 300…980 nm of uniaxially anisotropic polytetrafluoroethylene (PTFE) films were analyzed. We considered the capabilities and specific features of the graphical representation technique for determining the contribution of Rayleigh scattering and Urbach absorption to light attenuation in the spectral range beyond fundamental absorption. It has been shown that the graphical approach enables to estimate these contributions qualitatively, semi-quantitatively or quantitatively, depending on the situation. The conclusions made using the analysis of graphical representation are confirmed by numerical solution of the inverse problem via simulation of the αxy (λ), αz (λ) experimental dependences within the framework of a best-fit procedure. Being based on both of these approaches, we have ascertained that, in the as-prepared PTFE films, the so-called anomalous light scattering (ALS) with the spectral dependence of scattering coefficient αs ≈ as λ-p (p > 4) takes place. Transformation of scattering from ALS to the Rayleigh one with p ≈ 4 due to annealing is accompanied by an increase of Urbach (subband) absorption. Both of these factors cause narrowing the dynamic range of extinction coefficient values. Both scattering and absorption coefficients are higher for the component of light polarized along the normal to the substrate as compared to the component polarized in parallel to it. The relationship between observed behavior of the scattering and absorption coefficients and the film structure has been discussed.}, language = {en} } @article{GrytsenkoKolomzarovLytvynetal.2023, author = {Grytsenko, Kostyantyn and Kolomzarov, Yurii and Lytvyn, Peter and Kondratenko, Olga and Sopinskyy, Mykola and Lebedyeva, Iryna and Niemczyk, Agata and Baranowska, Jolanta and Moszyński, Dariusz and Villringer, Claus and Schrader, Sigurd}, title = {Optical and Mechanical Properties of Thin PTFE Films, Deposited from a Gas Phase}, series = {Macromolecular Materials and Engineering}, volume = {308}, journal = {Macromolecular Materials and Engineering}, number = {6}, publisher = {Wiley}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-17587}, year = {2023}, abstract = {Thin polytetrafluoroethylene (PTFE) films are produced by deposition from a gas phase by two methods: electron-enhanced vacuum deposition (EVD) and EVD + low-temperature plasma (LTP). Structure, morphology, and composition of the films are studied by IR spectroscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. They are close to the structure of bulk PTFE. The roughness of the films' surface is changed with gas pressure and LTP power variations. Films are transparent from UV to near-infrared regions. Refractive and extinction indices and their anisotropy are measured by spectral ellipsometry. They are tuned by variations of deposition conditions. Hardness and Young modulus of the films are increased if EVD + low power LTP is used for film deposition. Use of EVD + LTP also increases thermal stability of the films. Contact angle of the films corresponds to the bulk PTFE. The PTFE molecules oriented are preferentially in perpendicular direction to the substrate surface.}, language = {en} } @article{YeshchenkoDmitrukGrytsenkoetal.2009, author = {Yeshchenko, Oleg A. and Dmitruk, Igor M. and Grytsenko, Kostyantyn and Prokopets, Vadym M. and Kotko, Andriy V. and Schrader, Sigurd}, title = {Influence of interparticle interaction on melting of gold nanoparticles in Au/polytetrafluoroethylene nanocomposites}, series = {Journal of Applied Physics}, volume = {105}, journal = {Journal of Applied Physics}, number = {9}, issn = {1089-7550}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-9759}, year = {2009}, abstract = {The temperature dependence of the surface plasmon resonance energy and width in 5 nm spherical gold nanoparticles embedded in a polymer polytetrafluoroethylene matrix has been studied using absorption spectroscopy. The jumplike features have been observed in these dependences indicating the melting of gold nanoparticles at temperatures considerably lower than the bulk melting point. The interaction between gold nanoparticles sufficiently affects the melting of nanoparticles. The increase in the filling factor of the particles leads to a decrease in the melting temperature of gold nanoparticles.}, language = {en} } @inproceedings{GrytsenkoSlominskiiTolmachevetal.2008, author = {Grytsenko, Kostyantyn and Slominskii, Yu L. and Tolmachev, O. I. and Resel, R. and Ksensov, S. and Schrader, Sigurd}, title = {Enigma of the second harmonic generation in oriented film of symmetric squaraine}, publisher = {Society of Photo-Optical Instrumentation Engineers (SPIE)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-15183}, pages = {324 -- 331}, year = {2008}, abstract = {Second harmonic generation (SHG) in the oriented film of symmetric squaraine (Sq) was studied. Oriented Sq film on aligned polytetrafluoroethylyne (PTFE) sublayer prepared by vacuum deposition with subsequent rubbing using a cloth has been obtained. However, the mechanisms of orientation and SHG are still not clear. Methyl and ethyl substituted hydroxyl-Sq (OHSq) compounds formed oriented films with dichroic ratio of 8 on PTFE layer but with dichroic ratio of 1,5 on Teflon AF. Second layer deposition of Me-OHSq on Et-OHSq or of Et-OHSq on Me-OHSq led to an increase of the film dichroic ratio. Only the film, where Me-OHSq was first layer, exhibits an increase of SHG signal after deposition of second layer. Small differences in bi-layered OHSq films structure was detected by X-Ray diffraction (XRD) spectra.}, language = {en} } @inproceedings{GrytsenkoDoroshenkoKolomzarovetal.2008, author = {Grytsenko, Kostyantyn and Doroshenko, T. and Kolomzarov, Yurii and Prokopets, Vadym M. and Fedoriak, O. and Zelinski, R. and Lytvyn, Oksana and Prescher, Dietrich and Grimm, Bernd and Ksianzou, Viachaslau and Schrader, Sigurd and Tolmachev, O. I. and Slominskii, Yu L. and Kurdiukov, V. and Smirnova, G.}, title = {Research on the growth of dye film in vacuum in situ}, publisher = {Society of Photo-Optical Instrumentation Engineers (SPIE)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-15206}, pages = {318 -- 323}, year = {2008}, abstract = {Organic film deposition in vacuum is fast developing scientific and industrial domain. We developed installation for deposition of organic films equipped with optical spectrometer for measurements in situ. We are developing new dyes aimed for application in waveguide sensor, nonlinear optics and studying film organisation during deposition. Fluorinated azo-dyes and azomethine dyes were synthesized at University of Applied Sciences Wildau and at the Institute of Organic Chemistry, Kyiv. Compounds were evaporated at a pressure of 10-3 Pa using resistive heated crucible. Glass and glass covered with polytetrafluoroethylene (PTFE) film are used as substrates. The films were studied with Polytec and StellarNet spectrometers and an atomic force microscope. Optical spectra of the dye films revealed, that some compounds were decomposed during evaporation. Several kinds of dyes were evaporated and deposited without decomposition. Some deposited films formed H-aggregates and other types of aggregates. AFM images of dye films showed that their morphology depends on the chemical structure of the compounds and on the nature of the substrate on which the film was grown.}, language = {en} } @article{GrytsenkoSchraderDetert2014, author = {Grytsenko, Kostyantyn and Schrader, Sigurd and Detert, Heiner}, title = {Ultra-stable dye-filled polytetrafluoroethylene thin films}, series = {Nanoscience \& Technology: Open Access}, volume = {1}, journal = {Nanoscience \& Technology: Open Access}, number = {2}, issn = {2374-8141}, doi = {10.15771/2374-8141_2014_1}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-5947}, pages = {5}, year = {2014}, abstract = {Polytetrafluoroethylene (PTFE) and polyparaphenylene sulphide (PPS) thin films filled with molecules of different dyes were obtained by co-deposition in vacuum. The PTFE matrix prevented aggregation of dye molecules more strongly, than PPS matrix. During heating PTFE matrix kept the dye molecules in not aggregated state up to dye decomposition temperature. Dyes of all types, buried in the PTFE matrix, exhibited high stability toward actions of external factors: light, temperature, acids.}, language = {en} } @article{KsianzouVillringerGrytsenkoetal.2025, author = {Ksianzou, Viachaslau and Villringer, Claus and Grytsenko, Kostyantyn and Pekur, Demyd and Lytvyn, Peter and Sopinskyy, Mykola and Lebedyeva, Iryna and Niemczyk, Agata and Baranowska, Jolanta}, title = {Structural and Optical Anomalies in Thin Films Grown in a Magnetic Field by Electron-Assisted Vacuum Deposition of PTFE}, series = {Macromolecular Materials and Engineering}, volume = {310}, journal = {Macromolecular Materials and Engineering}, number = {3}, publisher = {Wiley}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-19712}, year = {2025}, abstract = {Polytetrafluoroethylene (PTFE) films are deposited in parallel and perpendicular magnetic fields (MF) by electron-enhanced vacuum deposition (EVD) and EVD + low-temperature plasma (LTP) methods. The structure, morphology, and nanomechanical properties of the films are studied by infrared spectroscopy (IRS), atomic force microscopy (AFM), and spectroscopic ellipsometry. The structure of the thicker films is closer to that of bulk PTFE than that of thin films. The films' crystallinity and surface roughness are higher than those deposited without MF. The birefringence of the refractive index (n) of the films deposited in the MF is inverse to the anisotropy of the n of the films deposited without MF. The hardness of the films is close to that of bulk PTFE.}, language = {en} }