Fiber plasma-treated

Fig. 7. Schematic of a self-contained plasma processing unit designed to continuously plasma-treat and impregnate with resin, reinforcing fibers for enhanced composite strength. The unit can also be used to plasma-treat wires to be coated or treated for improved adhesion. Throughput speeds of over...

Carbon fibers, 4 735 24 624 26 729-749 applications of, 26 745 cellulose-based, 26 735-736 crystallite dimensions in, 26 737-739 gas-phase grown, 26 736-737 PAN-based, 26 730-733 pitch-based, 26 733-735 plasma-treated, 26 744 processing of, 26 730-737 properties of, 26 739-743 prospects for, 26 746-747 quality control and specifications for, 26 745-746... 

Fig. 5.2,. Scunning cicciron micropholographs of (a) untreated and (b) plasma treated (120 s) Tekmilon UHMWPE fibers. After Tissington et al. (1991). Reproduced by permission of Chapman Hall.

Hild, D.N. and Schwart2, P. (1992a). Plasma treated ultrahigh strength polyethylene fibers, part I. Characterization by elctron spectroscopy for chemical analysis. J. Adhesion Sci. Technol. 6, 879 896. 

Wang, Q., Ait-kadi, A. and Kaliaguine, S. (1992a). Catalytic grafting a new technique for polymer/fiber composites. II. Plasma treated UHMPE fibers/polyelhylene composites. J. Appl. Polym. Sci. 45, 1023-1033. 

Carbon Is Electron Line Parameters Spectra From Plasma Treated Wool Fiber... 

Li et al. have reported results from tensile and pull-out tests on plasma-treated polyethylene fiber eonerete eomposites (/= 12.7mm, if=38pm, Ff = 2%) [32]. Among the three treatments (NH3, CO2, and Ar) investigated, NH3 plasma treatment provided the best improvement in bond strength (up to 35% over untreated fiber eomposites). 

Figure 30.28 Fatigue life of plasma-treated carbon fiber reinforced PMMA bone cement at 23 MPa maximum applied stresses under flexural loading untreated untreated carbon fiber with untreated X-ray opaque powder all others are with HMDSO/O2 treated X-ray opaque powder untreated refers to untreated carbon fiber.

From these comparisons it is clear that every quantum improvement in the fatigue cycles can be attributed to the plasma surface modifications of fillers. Among the improvement of fatigue properties by the plasma treatments on the carbon fibers, as shown in Figure 30.28, the oxygen plasma posttreatment showed a better effect that was already seen in the plasma treatment on the X-ray opaque powder. There were reports that the oxygen plasma-treated surface showed a better adhesion to PMMA than the argon plasma-treated surface [46 9]. 

Carbon fibers treated with HMDSO/O2 plasma showed the highest DPPH consumption per unit surface (2 x 10 mol/cm ) among plasma treatments employed, and also showed a significant reduction of the time needed to reach the maximal temperature (1070 s compared to 1170 s for untreated fibers). These are the similar trends found with plasma-treated X-ray-opaque powders. All of these trends strongly indicate that the plasma-treated fillers acting as the additional initiator of MMA polymerization, i.e., PMMA polymers are covalently bonded to the LCVD-coated fillers. 

Surface Energetics of Plasma-Treated Carbon Fiber... 

Plasma-induced hydrophobization of cottonfabric in conjunction with increased specific surface area leads to an interesting and practically important effect. Water droplets are able to effectively remove dirt particles from the surface of the cotton fabric. This phenomenon is illustrated in Fig. 9-29 for the case of HMDSO-plasma-treated cotton fabric (Hocker, 2002) and is usually referred to as the Lotus effect. Thus, the highly hydrophobic plasma-treated surface of cotton with specific plasma-modified surface topography is extremely dust- and dirt-repellant in contact with water. As an important consequence, the plasma-treated surface also becomes repellant to bacteria and fungi. The effect is relevant not only to cotton fiber but to some other materials as well. 

Besides plasma treated metal electrodes, carbon libers also adhere well to these PM A based EAPs. PMA based EAPs with embedded carbon fibers, arranged in long linear patterns or in grid patterns, respond very well to electricity, with marked contraction at 50 V with over 50% contraction by weight loss in a minute or less. Small cylindrical EAPs with embedded carbon fibers (Fig. 4.16) contracted and expanded when the polarity was reversed, albeit slowly, at voltages even as low as 1 V. 

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