Adhesion plasma treatment

D. J. Balazs, Surface Modification and Characterization of Endotracheal Tube Surfaces to Reduce Pseudomonas Aeruginosa Adhesion Plasma treatment, Plasma Polymerization and Chemical Methods (PhD Thesis EPFL no. 2748, 2003). 

Flame, hot air, electrical discharge, and plasma treatments change the surface of the polymer both physically and chemically. The plasma treating process has been found to be very successful on most low-energy surface plastics. Table 7.12 shows that plasma treatment results in improved plastic joint strength with common epoxy adhesive. Plasma treatment requires vacuum and special batch processing equipment. 

Wertheimer, M.R., Martinu, L., Klemberg-Sapieha, J.E., and Czeremuszkin, G., Plasma treatment of polymers to improve adhesion. In Mittal, K.L. and Pizzi, A. (Eds.), Adhesion Promotion Techniques — Technological Applications. Dekker, New York, 1999, pp. 139-174. 

Surface treatment of the composite can have a significant effect on adhesion. Surface treatment enhances one or more of the mechanisms described previously. Wu et al. [15] studied the effects of surface treatment on adhesive bonding for AS-4/APC-2 laminates. They found that the greatest bond strength was achieved from acid etching and plasma etching the composite surface. Table 1 summarizes the various surface treatments that were evaluated. 

In a previous section, the effect of plasma on PVA surface for pervaporation processes was also mentioned. In fact, plasma treatment is a surface-modification method to control the hydrophilicity-hydrophobicity balance of polymer materials in order to optimize their properties in various domains, such as adhesion, biocompatibility and membrane-separation techniques. Non-porous PVA membranes were prepared by the cast-evaporating method and covered with an allyl alcohol or acrylic acid plasma-polymerized layer the effect of plasma treatment on the increase of PVA membrane surface hydrophobicity was checked [37].The allyl alcohol plasma layer was weakly crosslinked, in contrast to the acrylic acid layer. The best results for the dehydration of ethanol were obtained using allyl alcohol treatment. The selectivity of treated membrane (H20 wt% in the pervaporate in the range 83-92 and a water selectivity, aH2o, of 250 at 25 °C) is higher than that of the non-treated one (aH2o = 19) as well as that of the acrylic acid treated membrane (aH2o = 22). 

Control of fiber friction is essential to the processing of fibers, and it is sometimes desirable to modify fiber surfaces for particular end-uses. Most fiber friction modifications are accomplished by coating the fibers with lubricants or finishes. In most cases, these are temporary treatments that are removed in final processing steps before sale of the finished good. In some cases, a more permanent treatment is desired, and chemical reactions are performed to attach different species to the fiber surface, e.g. siliconized slick finishes or rubber adhesion promoters. Polyester s lack of chemical bonding sites can be modified by surface treatments that generate free radicals, such as with corrosive chemicals (e.g. acrylic acid) or by ionic bombardment with plasma treatments. The broken molecular bonds produce more polar sites, thus providing increased surface wettability and reactivity. 

Some nonconductors, such as the polymers polycarbonates and polystyrenes, must be subjected to a surface treatment prior to activation to ensure good adhesion of palladium nuclei. Surface treatment can include the use of chemical etchants for plastics or reactive gas plasma treatments (66). 

Plasma treatment exposed to oxygen plasma al 150 mA, 26.6 Pa for 2 min. Coupling agent treatment coupled with silicone adhesive TSE322 at I50°C for 1 h. 

Ladizesky and Ward (1983, 1989), Ward and Ladizesky (1986) and Ward (1993) reported that plasma treatment of polyethylene fibers in an atmosphere of oxygen is the most effective among the many techniques studied. There are four major mechanisms responsible for improved fiber-matrix interface adhesion ... 

Bascom, W.D., Chen, W.J, (1991). Effect of plasma treatment on the adhesion of carbon fibers to thermoplastic polymers. J. Adhesion 34, 99-119. 

Biro, D.A., Pleizeier, G, and Deslandes, Y. (1993b). Application of the microbond technique. IV. Improved fiber matrix adhesion by RF plasma treatment of organic fibers. J. Appl. Polym. Sci. 47. 883-894. 

Gao. S. and Zeng, Y. (1993a). Surface modification of ultrahigh molecular weight polyethylene fibers by plasma treatment. I. Improving surface adhesion. J. Appi. Polym. Sci. 47, 2065-2071. 

Inagaki, N., Tasaka, S. and Kawai, H. (1992). Surface modification of Kevlar 49 fiber by a combination of plasma treatment and coupling agent treatment for silicon rubber composite. J. Adhesion Sci. Technol. 6, 279-291. 

Plasma treatment is useful to activate the surface of a certain material. The treatment enhances the adhesion property. Basically, surface activation effects the introduction of chemical functionalities on the polymer surface in order to increase its surface energy. 

The adhesion between phases and the dispersion state seem to play a very important role. To improve wetting behavior, dispersion, and adhesion by grafting reactions, a plasma treatment (02/N2/NH3) of the TP powders can be performed in a fluidized bed (Lennon et al., 2000a). 

Cao L, Sukavaneshvar S, Ratner BD, Horbett TA. Glow discharge plasma treatment of polyethylene tubing with tetraglyme results in ultralow fibrinogen adsorption and greatly reduced platelet adhesion. Journal of Biomedical Materials Research A 2006,79,788-803. 

Cell adhesion on a nonfunctional scaffold is mediated dominantly by nonspecific, entropically favored adsorption of a layer of cell adhesion proteins, excreted by the cell itself [61]. In order to obtain and retain the native function of these proteins, attempts are being made to tune the hydrophilicity or hydrophobicity of the scaffold surfaces [62], Different methods of surface activation are commonly applied, e.g., blending, copolymerization, plasma treatment, etching, radiation, chemical surface modification, coatings, and combinations of those. 

Adhesion of fluorosilicone compounds requires surface treatment. For particularly difficult surfaces plasma treatment is necessary. Flowever, for most common applications, satisfactory bonding is achieved by using a specialized primer.80... 

Fig. 8.4. Adhesion in the polar portion of the surface energy as a result of plasma treatment by BOPP [7].

Yoon TH, McGrath JE (1992) Enhanced adhesive performance of thermoplastic po-ly(imide siloxane) segmented copolymer with peek-graphite composites by gas plasma treatment. High Perform Polym 4(4) 203... 

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