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Silver nanolayers sputtered on polytetrafluoroethylene and their changes induced by post‐deposition annealing at 100–300 °C are studied. Changes in surface morphology and roughness are examined by atomic force microscopy and by measurement of electrical sheet resistance by two‐point technique. Chemical composition was determined by X‐ray photoelectron spectroscopy (XPS) and electrokinetic analysis in dependence on the gold layer thickness. The annealing at 300 °C leads to significant rearrangement of the silver layer, and the transition threshold increases to 35 nm. The presence of oxidized structures on silver‐coated samples is observed in XPS spectra and by electrokinetic analysis, too. Annealing of pristine and silver‐coated poly(tetrafluoroethylene) at 300 °C results in significant change of the sample surface morphology and chemistry. There is observed formation of isolated silver islands on the surface, which could be connected with silver melting. Later, the silver agglomeration takes place. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Monika Benkocká Regina Herma Simona Lupínková Petr Slepička Václav Švorčík Zdeňka Kolská 《Surface and interface analysis : SIA》2022,54(7):698-709
Octenidine dihydrochloride (OCT) has a wide spectrum of antibacterial, antifungal and virucidal activity. OCT is also newly used in tissue engineering. The aim of this work was to create a new nanocomposite consisting of OCT-grafted polymer with (i) antibacterial effect and/or (ii) surface for better cell adhesion and proliferation. The polymer foils were chemically activated with Piranha solution and subsequently grafted with OCT. Changes in surface properties before and after modifications were detected by electrokinetic analysis, goniometry, atomic force microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy. The final nanocomposite polymer/OCT exhibits antibacterial activity against Staphylococcus epidermidis (S. epidermidis). The new nanocomposite material has also been shown to support the growth of B14 cell culture on the substrate and to form cell multilayers, which could lead to the formation of spheroids. This behaviour strongly depends on the concentration of OCT grafted onto the polymer surfaces. This new nanocomposite could be used in medicine, for bioapplications, environmental protection. 相似文献
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V. ?vor?ík O. Kvítek O. Lyutakov J. Siegel Z. Kolská 《Applied Physics A: Materials Science & Processing》2011,102(3):747-751
Abstract The effects of annealing on gold structures sputtered onto glass substrate were studied using AFM, UV-Vis methods
and electrical measurements. The colour of the as-deposited films changes from blue to green with increasing deposition time.
After 1 hour annealing at 300°C the structures acquire red colour regardless of the film thickness. The annealing results
in dramatic changes of surface morphology and roughness and creation of relatively large “spherolytic and hummock-like” structures
in the gold layer. For deposited structures a non-zero optical band gap EgoptE_{\mathrm{g}}^{\mathrm{opt}} was determined from UV-Vis spectra using Tauc’s model and it indicates a semi-conducting character of the structures. The
annealing leads to an increase of the band gap. Electrical resistance of the deposited unannealed structures decreases dramatically
for deposition times above 50 s. For annealed structures the resistance fall comes until after 250 s deposition time. 相似文献
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V. Švorčík A. Chaloupka P. Řezanka P. Slepička Z. Kolská N. Kasálková T. Hubáček J. Siegel 《Radiation Physics and Chemistry》2010,79(3):315-317
Polyethylene (PE) surface was treated with Ar plasma. Activated surface was grafted from methanol solution of 1,2-ethanedithiol. Then the sample was immersed into freshly prepared colloid solution of Au-nanoparticles. Finally Au layer was sputtered on the samples. Properties of the modified PE were studied using various methods: AFM, EPR, RBS and nanoindentation. It was shown that the plasma treatment results in degradation of polymer chain (AFM) and creation of free radicals by EPR. After grafting with dithiol, the concentration of free radicals declines. The presence of Au and S in the surface layer after the coating with Au-nanoparticles was proved by RBS. Plasma treatment changes PE surface morphology and increases surface roughness, too. Another significant change in surface morphology and roughness was observed after deposition of Au-nanoparticles. Nanoindentation measurements show that the grafting with Au-nanoparticles increases adhesion of subsequently sputtered Au layer. 相似文献
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A. Řezníčková A. Chaloupka J. Heitz Z. Kolská V. Švorčík 《Surface and interface analysis : SIA》2012,44(3):296-300
Selected polymers (polyethylene‐PE, polypropylene‐PP, polytetrafluoroethylene‐PTFE, polystyrene‐PS and polyethylenterephthalate‐PET) were irradiated with the linearly polarized light of a pulsed 157 nm F2 laser. The irradiation results in degradation of polymers and ablation of polymer surfaces. Contact angle, measured by goniometry, was studied as a function of the number of laser pulses. The volume of the ablated polymer layer was determined by gravimetry. Changes in surface morphology and roughness were observed using atomic force microscopy. Surface chemistry of the samples was investigated by electrokinetic analysis and by XPS. While PET and PE exhibit small ablation, the ablation of PS and PTFE is more significant, and the most pronounced ablation is observed on PP. Contact angle of all polymers, with the only exception of PP, is a decreasing function of the number of laser pulses up to 2000 pulses. Laser irradiation leads to a refinement of the polymer surface morphology and a decrease of their surface roughness. Electrokinetic analysis and PS show changes in the surface chemistry of polymers after the laser treatment. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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