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1.
S.-J. Ding V. Zaporojtchenko J. Kruse J. Zekonyte F. Faupel 《Applied Physics A: Materials Science & Processing》2003,76(5):851-856
The interfacial bonding and mixing between evaporated aluminum and a vapor deposited Teflon AF (abbreviated to AF) film have
been investigated with X-ray photoelectron spectroscopy. Graphite carbon (C–C), and aluminum carbide (Al–C), oxide (Al–O–C)
and fluoride (Al–F) are formed when aluminum atoms are deposited on to the AF film. With increasing deposition of aluminum,
the concentrations of these newly formed components increase gradually. Moreover, in situ annealing results in remarkable
increases in the C–C, Al–C, Al–O–C and Al–F configurations and a decrease in metallic aluminum. No significant diffusion of
aluminum into the AF film was observed during the annealing. The Al compounds form a layer at the Al/AF interface that acts
as an adhesion promoter and diffusion barrier.
Received: 21 October 2002 / Accepted: 22 October 2002 / Published online: 15 January 2003
RID="*"
ID="*"Corresponding author. Fax: +49-431/880-6229, E-mail: sjding@yahoo.com 相似文献
2.
M. MüllerY. Gonzalez-Garcia C. PakulaV. Zaporojtchenko T. StrunskusF. Faupel R. HergesD. Zargarani O.M. Magnussen 《Applied Surface Science》2011,257(17):7719-7726
Thin films in the range 40-80 nm of a blend of PMMA with an azobenzene derivative have been studied directly during UV and blue light irradiation by atomic force microscopy (AFM), revealing highly reversible changes in the surface roughness and the film adhesion. UV light induces an ≈80% increase in surface roughness, whereas illumination by blue light completely reverses these changes. Based on the observed surface topography and transition kinetics a reversible mass flow mechanisms is suggested, where the polarity changes upon switching trigger a wetting-dewetting transition in a surface segregation layer of the chromophore. Similar AFM measurements of the pull-off force indicate a decrease upon UV and an increase after blue light illumination with a complex kinetic behavior: a rapid initial change, attributed to the change in the cis isomer fraction of the azobenzene derivative, and a more gradual change, indicative of slow structural reorganization. 相似文献
3.
Jung U Kuhn S Cornelissen U Tuczek F Strunskus T Zaporojtchenko V Kubitschke J Herges R Magnussen O 《Langmuir : the ACS journal of surfaces and colloids》2011,27(10):5899-5908
Adlayers of different azobenzene-functionalized derivatives of the triazatriangulenium (TATA) platform on Au(111) surfaces were studied by scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), gap-mode surface-enhanced Raman spectroscopy (gap-mode SERS), and cyclic voltammetry (CV). The chemical composition of the adlayers is in good agreement with the molecular structure, i.e., different chemical groups attached to the azobenzene functionality were identified. Furthermore, the presence of the azobenzene moieties in the adlayers was verified by the vibration spectra and electrochemical data. These results indicate that the molecules remain intact upon adsorption with the freestanding functional groups oriented perpendicularly to the TATA platform and thus also to the substrate surface. 相似文献
4.
M. Quitzau M. Wolter V. Zaporojtchenko H. Kersten F. Faupel 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,58(3):305-310
Hexamethyldisiloxane (HMDSO) films were deposited on polyethylene (PE, (C2H4)n) powder by hollow cathode glow
discharge. The reactive species in different HMDSO/Ar plasmas were studied by optical emission spectroscopy (OES). Increasing
the HMDSO fraction in the gas mixture additional compounds like CHx, OH, SiC and SiO can be identified. After deposition the
formed silicon and carbon containing groups (C–O, C=O, SiC and SiO) on the PE powder surface have been analyzed by X-ray
photoemission spectroscopy (XPS). Changes in wettability depending on the HMDSO fraction were investigated by contact angle
measurements (CAM). The free surface energy of the PE powder decreases with increasing HMDSO fraction in the process gas and
encapsulation of the powder particles occurs. An aging effect of the plasma treated PE surface was observed depending on the
process
gas composition. The higher the HMDSO fraction the less is the aging effect of the plasma treated PE surface. 相似文献
5.
Zaporojtchenko Vladimir Pakula Christina Basuki Sri Wahyuni Strunskus Thomas Zargarani Dordaneh Herges Rainer Faupel Franz 《Applied Physics A: Materials Science & Processing》2011,102(2):421-427
Fully reversible light-induced switching of the capacitance with changes larger than 50% has been achieved by using photo-active
thin polymer films. The films consist of PMMA polymer blended with high concentrations of branched azobenzene ether dye molecules.
Polymer thin sheet capacitors can be easily produced by spin coating and drop casting in various thicknesses ranging from
100 nm to 8 μm, respectively. Reversible capacitance switching is induced by illumination with UV and visible light, respectively.
The capacitance change is correlated to the trans to cis isomerization of the azobenzene ether molecules and the alignment of the molecular dipoles in the film. Switching times depend
on chromophore concentration, film thickness and light intensity used. The influence of wavelength of the light, of the temperature
as well as of an electrical field applied during illumination on the capacitance change is addressed. 相似文献
6.
7.
M. Iwamoto K. Kuroda V. Zaporojtchenko S. Hayashi F. Faupel 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,24(1-3):365-367
Recently, production methods of metal nanoparticles have
been investigated extensively, not only for a research use in
laboratory, but also for an industrial use. However, it is
difficult to obtain metal nanoparticles in high amounts and
concentrations with simple methods. In this study, a gold
nanoparticle-polymer composite was prepared with a simple
procedure using a gold salt and a melted polymer. The composite,
which is in a wax state at room temperature, was highly soluble
in water and lower alcohols, moreover the composite was melted
at about 50
°C. 相似文献
8.
Stephan Harms Klaus Rätzke Christina Pakula Vladimir Zaporojtchenko Thomas Strunskus Werner Egger Peter Sperr Franz Faupel 《Journal of Polymer Science.Polymer Physics》2011,49(6):404-408
Polymers including chromophores, which can be switched by light, have been studied extensively during the last years due to a host of potential applications which arise from the marked changes in physical properties on switching. Even though there is clear evidence that the free volume has a significant influence on the isomerization kinetics, the question of free volume changes on switching was only addressed recently. Using a pulsed low‐energy positron beam the ortho‐positronium lifetime τ3 was taken as a very sensitive free volume probe, and no change in free volume was detected on isomerization in an azobenzene‐polymethylmethacrylate (PMMA) copolymer containing about 8 wt % of the azobenzene moiety. Here, we report for the first time on free volume changes in an azobenzene‐PMMA blend with an azobenzene moiety concentration as high as 40 wt %. Using the same pulsed low‐energy positron beam, small but significant changes of τ3 were observed between the structurally relaxed dark and the UV‐illuminated states suggesting a decrease in free volume of the order of 10%. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011 相似文献
9.
Noble metals that are deposited on a polymer surface exhibit surface diffusion and diffusion into the bulk. At the same time the metal atoms tend to form clusters because their cohesive energy is about two orders of magnitude higher than the cohesive energy of polymers. To selfconsistently simulate these coupled processes, we present in this paper a Kinetic Monte Carlo approach. Using a simple model with diffusion coefficients taken as input parameters allows us to perform a systematic study of the behavior of a large ensemble of metal atoms on a polymer surface eventually leading to polymer nanocomposites. Special emphasis is placed on the cluster growth, cluster size distribution and the penetration of clusters into the substrate. We also study the influence of surface defects and analyze how the properties of the resulting material can be controlled by variation of the deposition rate (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
10.
XPS peak shape analysis is used as a novel and nondestructive method to study Au nano-cluster growth mechanism on polystyrene (PS) as a function of deposition as well as diffusion and distribution of the nano-clusters in PS as a function of subsequent annealing at temperatures in the range from room temperature to above the glass transition temperature of PS. The Au nano-cluster size and density are determined for four different amounts of Au deposition. It is shown that this nondestructive method can give all mentioned information on such a metalized polymer without the need for any other complimentary and time consuming technique such as AFM, TEM and the destructive technique XTEM. Thus this method is suitable to monitor and control the degree of intermixing of metal nano-clusters and polymers which is of high technological interest. 相似文献