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Oxygen Plasma (oxygen + plasma)

Distribution by Scientific Domains
Polymers and Materials Science72%
Physics and Astronomy18%
Distribution within Polymers and Materials Science
General & Introductory Materials Science62%
Polymer Science & Technology General25%

Terms modified by Oxygen Plasma

  • oxygen plasma etching
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  • oxygen plasma treatment
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    Selected Abstracts

    Comparison of Two Methods of Interpretation of LangmuirProbe Data for an Inductively Coupled Oxygen Plasma

    CONTRIBUTIONS TO PLASMA PHYSICS, Issue 5-6 2006
    T. H. Chung
    Abstract The Langmuir probe technique has some drawback in applying to electronegative plasma since it is difficult to interpret the probe I , V data. The positive ion flux to the probe is modified due to the presence of negative ions. In this study, an inductively coupled oxygen RF plasma is employed to perform the Langmuir probe measurement of the electronegative discharge. Plasma parameters are obtained from Langmuir probe measurement using two different methods which are based on electron energy distribution function (EEDF) integrals, and the method based on the fluid model for the modified ion flux, respectively. The EEDF is measured by a double differentiation of the I , V characteristics according to the Druyvesteyn formula. The electron densities estimated based on the two methods are compared. The EEDF integral method gives little higher values than the modified ion flux method. It is observed that at low pressure the EEDF is close to a Maxwellian. Generally, as the pressure increases, the distributions switch to bi-Maxwellian and to Druyvesteyn, and suggest some depletion of electrons with larger energies. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Stable Non-Covalent Large Area Patterning of Inert Teflon-AF Surface: A New Approach to Multiscale Cell Guidance,

    ADVANCED ENGINEERING MATERIALS, Issue 6 2010
    Francesco Valle
    Micro- and nano-patterning of cell adhesion proteins is demonstrated to direct the growth of neural cells, viz. human neuroblastoma SHSY5Y, at precise positions on a strongly antifouling substrate of technolological interest. We adopt a soft-lithographic approach with oxygen plasma modified PDMS stamps to pattern human laminin on Teflon-AF films. These patterns are based on the interplay of capillary forces within the stamp and non-covalent intermolecular and surface interactions. Remarkably, they remain stable for several days upon cell culture conditions. The fabrication of substrates with adjacent antifouling and adhesion-promoting regions allows us to reach absolute spatial control in the positioning of neuroblastoma cells on the Teflon-AF films. This patterning approach of a technologically-relevant substrate can be of interest in tissue engineering and biosensing. [source]

    Anode Interfacial Tuning via Electron-Blocking/Hole-Transport Layers and Indium Tin Oxide Surface Treatment in Bulk-Heterojunction Organic Photovoltaic Cells

    ADVANCED FUNCTIONAL MATERIALS, Issue 4 2010
    Alexander W. Hains
    Abstract The effects of anode/active layer interface modification in bulk-heterojunction organic photovoltaic (OPV) cells is investigated using poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and/or a hole-transporting/electron-blocking blend of 4,4,-bis[(p -trichlorosilylpropylphenyl)-phenylamino]biphenyl (TPDSi2) and poly[9,9-dioctylfluorene- co - N -[4-(3-methylpropyl)]-diphenylamine] (TFB) as interfacial layers (IFLs). Current,voltage data in the dark and AM1.5G light show that the TPDSi2:TFB IFL yields MDMO-PPV:PCBM OPVs with substantially increased open-circuit voltage (Voc), power conversion efficiency, and thermal stability versus devices having no IFL or PEDOT:PSS. Using PEDOT:PSS and TPDSi2:TFB together in the same cell greatly reduces dark current and produces the highest Voc (0.91,V) by combining the electron-blocking effects of both layers. ITO anode pre-treatment was investigated by X-ray photoelectron spectroscopy to understand why oxygen plasma, UV ozone, and solvent cleaning markedly affect cell response in combination with each IFL. O2 plasma and UV ozone treatment most effectively clean the ITO surface and are found most effective in preparing the surface for PEDOT:PSS deposition; UV ozone produces optimum solar cells with the TPDSi2:TFB IFL. Solvent cleaning leaves significant residual carbon contamination on the ITO and is best followed by O2 plasma or UV ozone treatment. [source]

    Siloxane Copolymers for Nanoimprint Lithography,

    ADVANCED FUNCTIONAL MATERIALS, Issue 1 2007
    P. Choi
    Abstract Presented here is the novel use of thermoplastic siloxane copolymers as nanoimprint lithography (NIL) resists for 60,nm features. Two of the most critical steps of NIL are mold release and pattern transfer through dry etching. These require that the NIL resist have low surface energy and excellent dry-etching resistance. Homopolymers traditionally used in NIL, such as polystyrene (PS) or poly(methyl methacrylate) (PMMA), generally cannot satisfy all these requirements as they exhibit polymer fracture and delamination during mold release and have poor etch resistance. A number of siloxane copolymers have been investigated for use as NIL resists, including poly(dimethylsiloxane)- block -polystyrene (PDMS- b -PS), poly(dimethylsiloxane)- graft -poly(methyl acrylate)- co -poly(isobornyl acrylate) (PDMS- g -PMA- co -PIA), and PDMS- g -PMMA. The presence of PDMS imparts the materials with many properties that are favorable for NIL, including low surface energy for easy mold release and high silicon content for chemical-etch resistance,in particular, extremely low etch rates (comparable to PDMS) in oxygen plasma, to which organic polymers are quite susceptible. These properties give improved NIL results. [source]

    Phase Separation of Polyfluorene-Based Blend Films and Its Influence on Device Operations,

    ADVANCED MATERIALS, Issue 11 2006
    Y. Xia
    Vertical phase separations have been found in blend films (TFB:F8BT) of polymer light-emitting diodes, giving rise to better device performances. A TFB wetting layer is present over most of the bottom interface with the substrate, as evidenced by the fluorescent microscopy images after top layers are etched away by oxygen plasma (see figure). [source]

    Superficial modification in recycled PET by plasma etching for food packaging

    JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010
    S. A. Cruz
    Abstract An oxygen plasma treatment has been used to improve the adhesion of amorphous hydrogenated carbon (a-C:H) films onto surfaces of recycled poly(ethylene terephthalate) (PET). Modifications produced by the oxygen plasma on the PET surface in chemical bonds and morphology were investigated by X-ray photoelectron spectroscopy and atomic force microscopy, respectively. Contact angle measurements were used to study the changes in the surface wettability. Adhesion of the a-C:H film onto the PET surface was investigated by the tape test method. It was observed that the improvement in film adhesion is in good correlation with the increase in surface roughness, due to plasma etching, and with the appearance of oxygen-related functional groups at the surface. The results of this study indicate that a-C:H-coated recycled PET can be used in food packaging. The a-C:H film could be used as a functional barrier to reduce or prevent migration of contaminants from the polymer to the package content. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

    Microwave Plasma Synthesis of Nanostructured ,-Al2O3 Powders

    JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 9 2003
    L. Fu
    Nanostructured Al2O3 powders have been synthesized by combustion of aluminum powder in a microwave oxygen plasma, and characterized by X-ray diffraction and electron microscopy. The main phase is ,-Al2O3, with a small amount of ,-Al2O3. The particles are truncated octahedral in shape, with mean particle sizes of 21,24 nm. The effect of reaction chamber pressure on the phase composition and the particle size was studied. The ,-alumina content increases and the mean particle size decreases with decreasing pressure. No ,-Al2O3 appears in the final particles. Electron microscopy studies find that a particle may contain more than one phase. [source]

    Long-term adsorption of fetal bovine serum on H/O-terminated diamond studied in situ by atomic force microscopy

    PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 11-12 2009
    E. Ukraintsev
    Abstract We investigate adhesion of fetal bovine serum (FBS) on diamond surfaces which have alternating H/O-terminated surface patterns of 30,µm width prepared by hydrogen and oxygen plasma. The samples are immersed into 15% FBS in McCoy's 5A supporting medium and characterized by in situ atomic force microscopy (AFM) during 6 days of adsorption. Within the first day, 2,4,nm primary layer is formed on both H-/O-terminated surfaces. After 6 days, we observe 17,±,5,nm FBS layer on O-terminated surface and 35,±,5,nm layer on H-terminated surface. Adhesion of the primary and secondary layer is weaker on H-terminated surface. We present a model of FBS protein layers on H-/O-terminated diamond and we discuss implications for a preferential cell growth on O-terminated diamond. We also show that the preferential cell growth is not affected by the long-term FBS pre-adsorption. [source]

    Front Cover: Plasma Process.

    PLASMA PROCESSES AND POLYMERS, Issue 4-5 2006
    Polym.
    Front Cover: Organosilicon plasma polymer thin films undergo modifications as they are exposed to an oxygen plasma. Under well chosen oxygen plasma conditions, they can even be converted into SiO2 -like films as shown by FTIR transmission spectra and X-ray reflectometry measurements. Further details can be found in the Full Paper by A. Granier*, G. Borvon, A. Bousquet, A. Goullet, C. Leteinturier, and A. van der Lee on page 365. [source]

    Generation of paramagnetic hybrid inorganic/organic thin films

    APPLIED ORGANOMETALLIC CHEMISTRY, Issue 7 2010
    Abhinav Bhushan
    Abstract There is a growing interest in developing advanced materials for thin film applications in biology, electronics, photonics and engineering. We report the development of hybrid inorganic/organic thin films containing nickel, iron and cobalt paramagnetic materials. By etching the resist in oxygen plasma after processing, most of the organic component of the resist was removed. The elemental chemical composition of the films was confirmed by energy dispersive X-ray spectroscopy. This process can potentially lead to patterning paramagnetic thin films containing paramagnetic materials by following standard photolithography protocols, obviating the need for a wet or vacuum metal deposition. Copyright © 2010 John Wiley & Sons, Ltd. [source]

    Synthesis of Al2O3,SiO2 Films by Ar/O2 Plasma-Enhanced CVD from Alkoxide Precursors,

    CHEMICAL VAPOR DEPOSITION, Issue 5 2006
    Y. Li
    Amorphous Al2O3, SiO2, and Al2O3,SiO2 composite films have been produced at 800,°C from alkoxide solution precursors by liquid-injection oxygen plasma enhanced CVD. The films' structures and morphologies are affected by the feed rate of the liquid precursor and their compositions can be controlled by adjusting the Si/Al ratios in the starting source. Steel substrates coated with the above films gained excellent protection when they were exposed to high temperature atmosphere containing KCl vapor. [source]