O -plasma treatment

Note A Fabrics activated by Ar-O plasma treatment (150 W) only. G Fabrics grafted wilii chitosan oligomer following plasma activation. 

Fig. 6 Wound healing assay of fibroblast cells (w/ and w/o plasma treatment), (a) images of scratch wound at 0, 12 and 22 hours APP treated (for 30 seconds) wound showed faster closure compared with untreated control, (b) the migration rate for APP treated wound and untreated control (at 12 and 22 hours after APP treatment) [23]...

Fig. 5.21. Surface amine concenlralion (O) of aramid fiber and ILSS ( ) of epoxy matrix composites as a function of ammonia plasma treatment time. After Brown et al. (1991).

Takeuchi K, Nakamura I, Matsumoto O, Sugihara S, Ando M, Ihara T. Preparation of visible-light-responsive titanium oxide photocatalysts by plasma treatment. Chem Lett 2000 1354-1355. 

Fig. 26. Y 3d (a), Ba3d5,2 (b) and O Is (c) emission spectra obtained at the surface of the inner grains of the YBaiCujOv before (------) and after (---) the CF4 + 25% 02 plasma treatment (reproduced with per-...

Scanning electron microscopy was used to detect changes in surface topography due to the plasma treatment. Preferential etching of the material will change the surface topography. The formation of volatile, low molecular weight species under the surface of the material can produce bubbles (O-... 

Figure 32.19 shows C/Si ratios formed from the XPS sputter depth profiles of the TMS plasma polymers with and without additional plasma treatment. As deposited, without a second plasma treatment, the closed system TMS plasma film has a surface that is carbon rich (with a C/Si ratio of about 4.7) and low oxygen content (with an O/Si ratio of about 0.7). From Figure 32.19a, it is observed that the as-deposited TMS plasma film shows a gradual structure change from the surface with more carbon (C/Si ratio of about 4.7) to lower carbon (C/Si ratio of about 1.7) in the bulk film. This also manifests itself as a higher C/Si ratio at the surface than the bulk value, which is unique to this film. 

Figure 32.21 Polarization resistance of TMS plasma coated Alcad 7075-T6 (Ace/O) aluminum substrates under IVD conditions (without anode assembly) with or without second plasma treatment 25 mtorr TMS + Ar (based on TMS/Ar ratios), DC 1000 V, 2 min for closed system TMS 1 seem TMS, 50 mtorr, DC 5 W, 1 min for flow system 2 seem oxygen or argon, 50 mtorr, 1 min for second plasma treatments.

In the case of CRS, approximately the same (Ar + H2) plasma treatment nearly completely removed oxides, and no O2 was found in the TMS film, as seen in Figure 33.9a. A small but clear O2 peak was found at the interface, but very small O2 was found in the film as depicted in Figure 33.9b, i.e., no feeding of O from oxides to depositing TMS film was observed beyond the transitional zone. 

The films deposited in various substrates after plasma treatment in the presence of perfluorinated olefins were subject to partial removal with extraction. Generally, after extraction, the fluorine to carbon ratio, determined through XPS analysis, decreased to 0.2 1 to 0.3 1 regardless of the applied power and residence time used during the fonnation of the film. In all cases a moderate but consistent amount of oxygen was detected in the fluorocarbon film. The oxygen to carbon ratio 0.12 1 to O.l t before extraction and 0.08 1 to 0.1 1 after extraction. 

Plasma (partially ionized gas) can be utilized to alter the surface characteristics of polymers by (1) exposing a surface of polymer to non-polymer-forming plasma (e.g., O, N, H2O, Ar, He, etc.) or by (2) depositing very thin layer of plasma polymer on a surface of polymer. Both processes can produce significant changes on the surface properties of polymers and can contribute to the improvement of wear resistance of polymers, since many changes which can be related to the wear resistance of polymers generally start to take place at the polymer surface. Fundamental aspects of plasma treatment of polymers and plasma polymerization are reviewed. 

Figure 9-35. Permeability of the lestosil polymer membrane with respect to He, H2, CO2, and CH4 as function of microwave plasma treatment time o, Hne A, Hhj , Hcch +, ncH< microwave pulse power2 kW pulsing period 2 ms pulse duration 100 fis gas pressure in the microwave discharge chamber2 Torr nitrogen/oxygen ratio in the plasma gas N2 02 = 4 1 flow rate of the plasma gas 40 cm /s.

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