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Wolfgang E S Unger - One of the best experts on this subject based on the ideXlab platform.
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surface analysis of plasma deposited polymer films 7 in situ characterization of plasma deposited allylamine films by tof ssims xps and nexafs spectroscopy
Plasma Processes and Polymers, 2006Co-Authors: Umut Oran, Sufal Swaraj, Andreas Lippitz, Wolfgang E S UngerAbstract:Plasma deposited allylamine films were studied by "in situ" ToF-SSIMS, XPS and NEXAFS Spectroscopy before exposure to ambient air. The influence of external plasma parameters such as duly cycle, plasma power, and Monomer Flow Rate on (i) unsamration, (ii) branching and cross-linking, (iii) nitrogen surface concentration and (iv) retention of amino groups was investigated. Harder plasma conditions, which can he obtained when high duty cycles, high plasma power, and low Monomer Flow Rates are employed, increase the unsauiRated, branched and crosslinked character of the plasma deposited films, while the surface concentration of N as well as the retention ol the Monomer's amino group decrease. As proven by NEXAFS findings and cross-checked by ToF-SSIMS results, the allylamine Monomer's primary amino groups are partially transformed into other nitrogen functionalities during its plasma polymerization. Amongst them imines and nitriles are the conversion products with the highest probabilities of formation. Another conversion channel is the formation of nitrogen species not participating in the film growth. '['his is the reason for an increased N loss in plasma deposited allylamine films as observed independently by XPS and ToF-SSIMS when the plasma parameters are changed from mild to hard. Summations of π*(C=N) and π*(C≡N) resonance intensities for NEXAFS N K-edge spectra measured with plasma deposited allylamine films vs. variation olduty cycle, or power.
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Surface Analysis of Plasma‐Deposited Polymer Films, 6
Plasma Processes and Polymers, 2005Co-Authors: Sufal Swaraj, Umut Oran, Andreas Lippitz, Jörg Friedrich, Wolfgang E S UngerAbstract:XPS and NEXAFS spectroscopy results were used for chemical characterization of pulsed plasma deposited allyl alcohol films before and after exposure to ambient air. The influence of the composite plasma parameter, effective plasma power (P) to Monomer Flow Rate (F) ratio on the spectroscopic results was investigated. From this data, information about the chemical character of the plasma polymerized films, such as retention of the hydroxyl groups in the deposited sample, the amount of long living radicals and branching and/or crosslinking was derived. A high degree of hydroxyl retention was observed, which, however, decreased along with the oxygen content of the film, as the P/F ratio increased. A trend in the extent of the oxygen loss according to the variation of the P/F ratio was deduced, which agrees with earlier ToF-SSIMS findings (Plasma Process. Polym. 2005, 2, 563).
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Surface Analysis of Plasma Deposited Polymer Films, 5
Plasma Processes and Polymers, 2005Co-Authors: Umut Oran, Sufal Swaraj, Jörg Friedrich, Wolfgang E S UngerAbstract:The effect of the composite plasma parameter P/ F, where P is the plasma power and F is the Monomer Flow Rate, on the chemical character of pulsed plasma deposited allyl alcohol films was investigated by ToF-SSIMS. Information on the unsatuRated character, the cross-linked and/or branched character of the plasma polymer films was derived in detail. The problem of the retention of OH groups in plasma deposited allyl alcohol films was elucidated in detail using SSIMS data. The lowest conversion Rate from the Monomer's hydroxyl groups to other oxygen functionalities in the plasma was concluded for the plasma polymer film produced at a P/F ratio of 0.05 W . sccm - 1 . It was found that the overall oxygen content of the films decreased vs. increasing P/F ratio. Because the freshly prepared films were investigated without air exposure, ageing on ambient air could be studied in detail. It was found that in the case of plasma deposited allyl alcohol films the ageing on air is probably based on two competing processes which are discussed in detail. Additionally, a review of literature data on the characterization of plasma deposited allyl alcohol films is given.
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Surface analysis of plasma-deposited polymer films by Time of Flight Static Secondary Ion Mass Spectrometry (ToF-SSIMS) before and after exposure to ambient air
Surface & Coatings Technology, 2005Co-Authors: Umut Oran, Sufal Swaraj, J.f. Friedrich, Wolfgang E S UngerAbstract:Abstract Pulsed plasma deposited styrene and ethylene films were studied by Time of Flight Static Secondary Ion Mass Spectrometry (ToF-SSIMS) before and after exposure to ambient air. The influence of the external plasma parameters on the secondary ion mass spectra of plasma deposited films was investigated. Approaches for the interpretation of SSIMS spectra of organic materials were reviewed and applied to the evaluation of SSIMS data of plasma deposited films. From these data, information on the chemical character of the plasma deposited films was derived. When the plasma polymers are exposed to air oxygen incorporation occurs. The oxygen uptake is high at the beginning and then it levels of. A relation that “higher the regularity of the film lower is the oxygen uptake” was found. Harder plasma conditions, which could be obtained by applying higher plasma power or lower Monomer Flow Rate, result in higher oxygen uptake and vice versa.
Umut Oran - One of the best experts on this subject based on the ideXlab platform.
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surface analysis of plasma deposited polymer films 7 in situ characterization of plasma deposited allylamine films by tof ssims xps and nexafs spectroscopy
Plasma Processes and Polymers, 2006Co-Authors: Umut Oran, Sufal Swaraj, Andreas Lippitz, Wolfgang E S UngerAbstract:Plasma deposited allylamine films were studied by "in situ" ToF-SSIMS, XPS and NEXAFS Spectroscopy before exposure to ambient air. The influence of external plasma parameters such as duly cycle, plasma power, and Monomer Flow Rate on (i) unsamration, (ii) branching and cross-linking, (iii) nitrogen surface concentration and (iv) retention of amino groups was investigated. Harder plasma conditions, which can he obtained when high duty cycles, high plasma power, and low Monomer Flow Rates are employed, increase the unsauiRated, branched and crosslinked character of the plasma deposited films, while the surface concentration of N as well as the retention ol the Monomer's amino group decrease. As proven by NEXAFS findings and cross-checked by ToF-SSIMS results, the allylamine Monomer's primary amino groups are partially transformed into other nitrogen functionalities during its plasma polymerization. Amongst them imines and nitriles are the conversion products with the highest probabilities of formation. Another conversion channel is the formation of nitrogen species not participating in the film growth. '['his is the reason for an increased N loss in plasma deposited allylamine films as observed independently by XPS and ToF-SSIMS when the plasma parameters are changed from mild to hard. Summations of π*(C=N) and π*(C≡N) resonance intensities for NEXAFS N K-edge spectra measured with plasma deposited allylamine films vs. variation olduty cycle, or power.
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Surface Analysis of Plasma‐Deposited Polymer Films, 6
Plasma Processes and Polymers, 2005Co-Authors: Sufal Swaraj, Umut Oran, Andreas Lippitz, Jörg Friedrich, Wolfgang E S UngerAbstract:XPS and NEXAFS spectroscopy results were used for chemical characterization of pulsed plasma deposited allyl alcohol films before and after exposure to ambient air. The influence of the composite plasma parameter, effective plasma power (P) to Monomer Flow Rate (F) ratio on the spectroscopic results was investigated. From this data, information about the chemical character of the plasma polymerized films, such as retention of the hydroxyl groups in the deposited sample, the amount of long living radicals and branching and/or crosslinking was derived. A high degree of hydroxyl retention was observed, which, however, decreased along with the oxygen content of the film, as the P/F ratio increased. A trend in the extent of the oxygen loss according to the variation of the P/F ratio was deduced, which agrees with earlier ToF-SSIMS findings (Plasma Process. Polym. 2005, 2, 563).
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Surface Analysis of Plasma Deposited Polymer Films, 5
Plasma Processes and Polymers, 2005Co-Authors: Umut Oran, Sufal Swaraj, Jörg Friedrich, Wolfgang E S UngerAbstract:The effect of the composite plasma parameter P/ F, where P is the plasma power and F is the Monomer Flow Rate, on the chemical character of pulsed plasma deposited allyl alcohol films was investigated by ToF-SSIMS. Information on the unsatuRated character, the cross-linked and/or branched character of the plasma polymer films was derived in detail. The problem of the retention of OH groups in plasma deposited allyl alcohol films was elucidated in detail using SSIMS data. The lowest conversion Rate from the Monomer's hydroxyl groups to other oxygen functionalities in the plasma was concluded for the plasma polymer film produced at a P/F ratio of 0.05 W . sccm - 1 . It was found that the overall oxygen content of the films decreased vs. increasing P/F ratio. Because the freshly prepared films were investigated without air exposure, ageing on ambient air could be studied in detail. It was found that in the case of plasma deposited allyl alcohol films the ageing on air is probably based on two competing processes which are discussed in detail. Additionally, a review of literature data on the characterization of plasma deposited allyl alcohol films is given.
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Surface analysis of plasma-deposited polymer films by Time of Flight Static Secondary Ion Mass Spectrometry (ToF-SSIMS) before and after exposure to ambient air
Surface & Coatings Technology, 2005Co-Authors: Umut Oran, Sufal Swaraj, J.f. Friedrich, Wolfgang E S UngerAbstract:Abstract Pulsed plasma deposited styrene and ethylene films were studied by Time of Flight Static Secondary Ion Mass Spectrometry (ToF-SSIMS) before and after exposure to ambient air. The influence of the external plasma parameters on the secondary ion mass spectra of plasma deposited films was investigated. Approaches for the interpretation of SSIMS spectra of organic materials were reviewed and applied to the evaluation of SSIMS data of plasma deposited films. From these data, information on the chemical character of the plasma deposited films was derived. When the plasma polymers are exposed to air oxygen incorporation occurs. The oxygen uptake is high at the beginning and then it levels of. A relation that “higher the regularity of the film lower is the oxygen uptake” was found. Harder plasma conditions, which could be obtained by applying higher plasma power or lower Monomer Flow Rate, result in higher oxygen uptake and vice versa.
Jean Durand - One of the best experts on this subject based on the ideXlab platform.
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Modelling of gas permeability for membranes prepared by PECVD
Journal of Membrane Science, 2005Co-Authors: A. Mourgues, Stéphanie Roualdes, José Sanchez, Jean DurandAbstract:Abstract Plasma polymerization is a very powerful technique for preparing very thin highly cross-linked polymeric films. As in the case of classical polymers, the gas permeation performances of plasma polymers are strongly related to their chemical composition and structural properties. These properties depend directly on the precursor nature and on the operating conditions of the polymerization process like temperature, Monomer Flow Rate, discharge power, frequency, etc. Previous results obtained by our group show that it is difficult to apply the classical Fick's correlations between the permeability, sorption and diffusion to this type of polymer. In addition, their structure, which is not very well known, is very cross-linked, high disordered and behaves like a complex material with two components: a rubber and an inorganic part. Indeed, these polymers cannot be represented as a regular repeat of Monomer units. A mathematical model inspired from the free volume concept and Bondi's contributions group has been proposed for the DEDMS, HMCTSO, HMDSO and OMTSO polymers. This model is based on mesoscopic parameters like the density of the polymer and factor T = number of (Si–C) bonds/number of (Si–O) bonds. The model has displayed good correlations factors for the studied polymers.
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Comparative performance of various plasma polysiloxane films for the pervaporative recovery of organics from aqueous streams
Journal of Membrane Science, 2003Co-Authors: Stéphanie Roualdes, Jean Durand, Robert W. FieldAbstract:Abstract Thin SiO x C y H z film membranes were deposited from two different organosilicon precursors, one cyclic and one linear, in a low-frequency plasma polymerisation process. The ability of the films for effective recovery of various organic contaminants from aqueous waste was tested using the process of pervaporation. Four sepaRate organic components, phenol, chloroform, pyridine and methylisobutylketone (MIBK), each representative of an industrially significant family of chemicals, were chosen for evaluation. Trends between the pervaporation performances of plasma polysiloxane membranes and the composite plasma parameter V / FM ( V : input voltage; F : Monomer Flow Rate; M : Monomer molecular weight) were found. Pervaporation measurements reveal that polysiloxane membranes synthesised by the plasma deposition process are sufficiently permeable for the mass transfer boundary layer above the membrane to be dominant. The permeability of plasma membranes formed from cyclic octamethylcyclotetrasiloxane were up to an order of magnitude more permeable than those formed from linear hexamethyldisiloxane. Future work should involve vapour permeation.
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Gas diffusion and sorption properties of polysiloxane membranes prepared by PECVD
Journal of Membrane Science, 2002Co-Authors: Stéphanie Roualdes, José Sanchez, Jean DurandAbstract:Abstract Thin a-SiO x C y H z film membranes were deposited from two different cyclic and linear organosilicon precursors in a low-frequency plasma polymerization process. The qualification of the films for effective gas permeation membranes was tested on the ester of cellulose substRates using N 2 , H 2 , CO 2 and CH 4 . The gas permeability and diffusion coefficients were determined by using the constant-volume pressure-increase method. The solubility coefficients ( S ) were obtained by using a gravimetric method with a quartz microbalance. Correlations between the composite plasma parameter ( V / FM ) ( V : input voltage, F : Monomer Flow Rate and M : Monomer molecular weight), which describes the energetic character of the plasma and the permeation performances of plasma polysiloxane membranes were established. Permeation measurements reveal that a wide range of gas transport properties can be obtained according to the applied plasma energy. The global mass transfer could be controlled by diffusion or sorption mechanism according to the relative influence of the different structural factors (chain packing density, chain flexibility and chemical composition) of plasma polysiloxane films directly related to deposition parameters.
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Hybrid plasma polymerized membranes from organosilicon precursors for gas separation
Journal De Physique Iv, 1999Co-Authors: Stéphanie Roualdes, Arie Van Der Lee, José Sanchez, Nadine Hovnanian, Jean DurandAbstract:Thin a-SiO x C y H z films were deposited from different cyclic and linear organosilicon precursors in a radio-frequency plasma polymerization process. The plasma deposition and the film properties were characterized with respect to the deposition Rate, the layers density and the chemical structure determined by FTIR and 29 Si NMR analysis. The qualification of the films for gas-selective membranes was tested on ester of cellulose substRates using N 2 , H 2 , O 2 , CO 2 and CH 4 . We are able to correlate both physico-chemical properties and permeation performances of the synthesized polymers with the composite parameter V/F.M (V: input voltage. F: Monomer Flow Rate. M: Monomer molecular weight) which describes the energetic character of the plasma. At low V/F.M ratios, the thin layers extremely preserve the Monomeric structure and get close to polydimethylsiloxane; this resemblance is all the more considerable that the precursor siloxane chain is longer, and particularly pronounced using cyclic Monomers. As V/F.M increases, the plasma polymers have a more inorganic structure and higher density: the materials tend towards a silica-like structure. Concurrently, the synthesized membranes exhibit solution-diffusion controlled or Knudsen-like separation factors depending on whether plasma conditions are soft (low V/F.M ratios) or drastic (high V/F.M ratios).
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Gas separation properties of organosilicon plasma polymerized membranes
AIChE Journal, 1999Co-Authors: Stéphanie Roualdes, Arie Van Der Lee, René Berjoan, José Sanchez, Jean DurandAbstract:Thin films were polymerized from different organosilicon compounds in a radio-frequency plasma deposition process. The properties of the layers were characterized with respect to the deposition Rate, the density, the refractive index, and the chemical structure determined by FTIR and XPS analysis. The qualification of the films for gas-selective membranes was tested on different porous substRates using N2, H2, O2, CO2, and CH4. Both structure and permeation performances of the synthesized films were correlated with the composite plasma parameter V/F·M (V: input voltage; F: Monomer Flow Rate; M: Monomer molecular weight). At low V/F·M ratio, the thin layers are mainly constituted of the [(CH3 )2–Si(–O)2] environment (Monomer and polydimethylsiloxane one). Increasing the V/F·M results in a more “inorganic” chemical structure, higher O/Si ratio, refractive index, and density, the materials tend toward a silicalike structure. Concurrently, the prepared membranes have solution–diffusion-controlled or Knudsen-like separation factors, depending on whether plasma conditions are soft or hard.
Sufal Swaraj - One of the best experts on this subject based on the ideXlab platform.
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surface analysis of plasma deposited polymer films 7 in situ characterization of plasma deposited allylamine films by tof ssims xps and nexafs spectroscopy
Plasma Processes and Polymers, 2006Co-Authors: Umut Oran, Sufal Swaraj, Andreas Lippitz, Wolfgang E S UngerAbstract:Plasma deposited allylamine films were studied by "in situ" ToF-SSIMS, XPS and NEXAFS Spectroscopy before exposure to ambient air. The influence of external plasma parameters such as duly cycle, plasma power, and Monomer Flow Rate on (i) unsamration, (ii) branching and cross-linking, (iii) nitrogen surface concentration and (iv) retention of amino groups was investigated. Harder plasma conditions, which can he obtained when high duty cycles, high plasma power, and low Monomer Flow Rates are employed, increase the unsauiRated, branched and crosslinked character of the plasma deposited films, while the surface concentration of N as well as the retention ol the Monomer's amino group decrease. As proven by NEXAFS findings and cross-checked by ToF-SSIMS results, the allylamine Monomer's primary amino groups are partially transformed into other nitrogen functionalities during its plasma polymerization. Amongst them imines and nitriles are the conversion products with the highest probabilities of formation. Another conversion channel is the formation of nitrogen species not participating in the film growth. '['his is the reason for an increased N loss in plasma deposited allylamine films as observed independently by XPS and ToF-SSIMS when the plasma parameters are changed from mild to hard. Summations of π*(C=N) and π*(C≡N) resonance intensities for NEXAFS N K-edge spectra measured with plasma deposited allylamine films vs. variation olduty cycle, or power.
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Surface Analysis of Plasma‐Deposited Polymer Films, 6
Plasma Processes and Polymers, 2005Co-Authors: Sufal Swaraj, Umut Oran, Andreas Lippitz, Jörg Friedrich, Wolfgang E S UngerAbstract:XPS and NEXAFS spectroscopy results were used for chemical characterization of pulsed plasma deposited allyl alcohol films before and after exposure to ambient air. The influence of the composite plasma parameter, effective plasma power (P) to Monomer Flow Rate (F) ratio on the spectroscopic results was investigated. From this data, information about the chemical character of the plasma polymerized films, such as retention of the hydroxyl groups in the deposited sample, the amount of long living radicals and branching and/or crosslinking was derived. A high degree of hydroxyl retention was observed, which, however, decreased along with the oxygen content of the film, as the P/F ratio increased. A trend in the extent of the oxygen loss according to the variation of the P/F ratio was deduced, which agrees with earlier ToF-SSIMS findings (Plasma Process. Polym. 2005, 2, 563).
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Surface Analysis of Plasma Deposited Polymer Films, 5
Plasma Processes and Polymers, 2005Co-Authors: Umut Oran, Sufal Swaraj, Jörg Friedrich, Wolfgang E S UngerAbstract:The effect of the composite plasma parameter P/ F, where P is the plasma power and F is the Monomer Flow Rate, on the chemical character of pulsed plasma deposited allyl alcohol films was investigated by ToF-SSIMS. Information on the unsatuRated character, the cross-linked and/or branched character of the plasma polymer films was derived in detail. The problem of the retention of OH groups in plasma deposited allyl alcohol films was elucidated in detail using SSIMS data. The lowest conversion Rate from the Monomer's hydroxyl groups to other oxygen functionalities in the plasma was concluded for the plasma polymer film produced at a P/F ratio of 0.05 W . sccm - 1 . It was found that the overall oxygen content of the films decreased vs. increasing P/F ratio. Because the freshly prepared films were investigated without air exposure, ageing on ambient air could be studied in detail. It was found that in the case of plasma deposited allyl alcohol films the ageing on air is probably based on two competing processes which are discussed in detail. Additionally, a review of literature data on the characterization of plasma deposited allyl alcohol films is given.
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Surface analysis of plasma-deposited polymer films by Time of Flight Static Secondary Ion Mass Spectrometry (ToF-SSIMS) before and after exposure to ambient air
Surface & Coatings Technology, 2005Co-Authors: Umut Oran, Sufal Swaraj, J.f. Friedrich, Wolfgang E S UngerAbstract:Abstract Pulsed plasma deposited styrene and ethylene films were studied by Time of Flight Static Secondary Ion Mass Spectrometry (ToF-SSIMS) before and after exposure to ambient air. The influence of the external plasma parameters on the secondary ion mass spectra of plasma deposited films was investigated. Approaches for the interpretation of SSIMS spectra of organic materials were reviewed and applied to the evaluation of SSIMS data of plasma deposited films. From these data, information on the chemical character of the plasma deposited films was derived. When the plasma polymers are exposed to air oxygen incorporation occurs. The oxygen uptake is high at the beginning and then it levels of. A relation that “higher the regularity of the film lower is the oxygen uptake” was found. Harder plasma conditions, which could be obtained by applying higher plasma power or lower Monomer Flow Rate, result in higher oxygen uptake and vice versa.
Mehmet Mutlu - One of the best experts on this subject based on the ideXlab platform.
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modification of food contacting surfaces by plasma polymerisation technique part i determination of hydrophilicity hydrophobicity and surface free energy by contact angle method
Journal of Food Engineering, 2006Co-Authors: Haci Ali Gulec, Kemal Sariogˇlu, Mehmet MutluAbstract:Abstract In this study, the surface characteristics of three major materials which are widely used in food industry, glass, polyethylene (PE) and stainless steel (SS 316), were studied. The hydrophilicity, hydrophobicity and surface free energy (SFE) of those surfaces were determined by contact angle measurements prior and after plasma polymerisation treatment. The modification of the surfaces was carried out at low pressure and low temperature plasma conditions by using different Monomers with functional properties. Phenol and 1,1,1,3,3,3-hexaflouroisopropylacrylate (HFIPA) were used to produce hydrophobic materials with low surface energy, and hydroxyethylmethacrylate (HEMA), ethylenediamine (EDA), polyethyleneglycolethylethermethacrylate (PEGEEMA) and polyethyleneglycolmethacrylate (PEGMA) were used to produce hydrophilic materials with higher surface energy. The effects of Monomer Flow Rate, exposure time and discharge power parameters were optimized by comparing surface characteristics before and after plasma polymerisation treatments. Contact angle measurements were performed by using the captive bubble technique, and the geometric mean equation was used to calculate the surface free energy values. Air and n-octane bubbles with different polarity were used to determine the changes on the surface energy including the dispersive and polar components. Polyethylene was the most hydrophobic material among the materials used in this study related to its air contact angle and γsw values. γsw value was found 38.91 mJ/m2 for polyethylene. Glass was determined as the most hydrophilic material (γsw: 1.11 mJ/m2) among the used surfaces, and its surface energy (γsv) was 58.95 mJ/m2. The contact angle and SFE values were affected by Monomer Flow Rate, exposure time and power parameters used for all modification processes. The equilibrium between etching and deposition processes can be controlled by these plasma parameters. Therefore, we tried to optimize plasma parameters according to the results from contact angle and surface energy data.
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performance of amperometric alcohol electrodes prepared by plasma polymerization technique
Analytica Chimica Acta, 2002Co-Authors: Dilek Cokeliler, Mehmet MutluAbstract:Abstract A single-layer alcohol electrode was prepared by plasma polymerization technique. Ethylenediamine was used to incorpoRate amino groups on tract-etched polycarbonate membranes in glow discharge reactor. In order to determine the plasma polymerization parameters (discharged power, Monomer Flow Rate, exposure time) on membrane permeability, hydrogen peroxide was used as tracer. The single-layer alcohol electrode that was produced by 0.6% (w/v) of alcohol oxidase (AOx) solution on the polycarbonate membrane, which was modified at 30 W, 20 ml/min Monomer Flow Rate and 15 min exposure time, was selected for optimum performance. Sensitivity, linearity and response time of that particular layer were 5.6 nA/mM, 2 mM and 50 s, respectively. The performance of the amperometric alcohol electrode was tested on commercial alcoholic beverages.