Argon-plasma treatment

The immobilisation of unsaturated surfactant sodium 10-undecenoate [Cl 1( )] and the saturated surfactant sodium dodecanoate (C12) was carried out on PE surfaces [266] by means of an argon plasma treatment and characterised using XPS and SSIMS techniques. The typical SSIMS spectra for unmodified and modified PE films are shown in Fig. 21. The differences in the SSIMS spectra of PE and that of PE/C11( ) and PE/C11( )-Ar 5 are merely the spectra of the surfactant which can be attributed to the presence of a layer of Cll( ) on the PE sample. The SSIMS analysis showed that during... 

Radio Frequency Argon Plasma Treatment of Parylene C Films... 

Radio frequency argon plasma treatment of Parylene C surfaces is very attractive because two processes—Parylene deposition and plasma treatment—can be carried out in the same reactor, the Parylene reactor. It was found that radio frequency... 

Since it was observed that fluorine contamination was a possibility and had potentially detrimental effects as described in Chapter 10, the excellent primer adhesion achieved with Tfs/(Ar) and Tcs/(Ar), shown in Table 31.3, has significant importance in the practical application of the plasma technique without any of the potentially deleterious effects of fluorine-based systems. Argon plasma treatments on both flow system TMS (Tfs) and closed system TMS (Tcs) polymers were then investigated as an additional system modification that could provide strong adhesion without the incorporation of fluorine-containing monomers in the quest to produce chromate-free coatings systems. 

T/(Ar) TMS plasma polymerization succeeded by argon plasma treatment under the following conditions 1 seem argon, 50 mtorr, 10 W, 1 min... 

Fig. 2 Temperature-dependent swelling behaviour of PNIPAAm and poly(NiPAAm-co-DEG-MA) thin films immobilised by low-pressure argon plasma treatment (reproduced from (Nitschke et al. 2007a) with permission)...

Zhu X, Chian KS, Chan-Park MB, Lee ST. Effect of argon-plasma treatment on proliferation of human-skin-derived fibroblast on chitosan membrane in vitro. J Biomed Mater Res A 2005 73 264-274. 

Vidaurre et al. studied argon plasma-treated (at room temperature) asymmetric polysulfone (PSf) membranes (MWCO 10 000 Da, Danish Separation Systems AS) by AFM imaging [40]. Figure 4.19a and b shows the surface of the polysulfone membranes before and after 10 min of argon plasma treatment, respectively. Comparing the two figures, a remarkable reduction in pore sizes by the plasma treatment can be noticed. Moreover, the roughness parameter, R, decreased from 1.6 nm before the... 

Fig. 4.21. Nitrogen permeability through UF PSf membranes after argon plasma treatment at 5W. Reprinted from [40] with kind permission from Materials Research, Universidade Federal de Sao Carlos...

Other surface modification techniques include the use of free radical-, photochemical-, radiation- redox- and plasma-induced grafting. These are used to covalently attach some useful monomers onto the membrane surface [20]. Gas plasma treatment is also used to induce surface modification water permeabihty is improved by oxygen plasma treatment due to the introduction of hydrophihc carboxylate groups, whereas argon plasma treatment can enhance chlorine resistance by increasing the extent of cross-linking at the nitrogen sites. 

Air or argon plasma treatment has been widely used as a facile surface modification technique for many biomaterials since its surface hydrophilicity can be easily increased with this treatment. Yoon et al. (2009) investigated the preparation and... 

Cardiovascular rotary blood pump Ti substate 1) hydrojy lation 2) silanation 3) argon-plasma treatment and exposure to air 4) UV radiation-induced grafting of MFC 46... 

Hydrogel Coating ofPoly(ether sulfone). Due to the fact that PES has no functional groups which allow a wet chemical modification, plasma-induced hydroperoxide formation presents a suitable method to carry out the subsequent thermoinitiated graftpolymerization of HEMA (cf. Fig. 12). The iodometric determination of the hydroperoxide concentration at the surface shows that a saturation value is achieved after 4 min of argon plasma treatment and subsequent air exposure [113]. 

To achieve enhanced cell adhesion and proliferation in vitro which probably leads to a better integration of the prosthesis into the surrounding tissue the cell adhesion mediator fibronectin was coupled to the surface of silicone. Figure 40 shows the two principal steps of the appHed surface modification procedure. Argon plasma treatment and subsequent exposure to air of the silicone samples leads to the formation of hydroperoxide groups on its surface which are used to initiate polymerization of acrylic acid (AAc), methacrylic acid (MAAc) and gly-cidyl methacrylate (GMA) generating carboxylic and epoxy groups, respectively. 

Glycopolymers were recently grafted onto PET fibers by double plasma treatment in order to obtain a surface compatible with biological material. The first step is activation of the PET surface by argon plasma treatment leading to the formation of radicals by scission of the chemical bonds. Then, fibers are exposed to air in order to form (hydro)peroxides functions. The activated fibers are dipped in glycomonomers solutions and dried. A second plasma treatment is applied to polymerize the monomers adsorbed on fibers (43). 

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