Plasma treatments etching effect

Flat porous poly(vinylidene fluoride) hydrophobic membranes were used for the removal and the recovery of CO2 from the emission sources (Lin et al. 2009b). Methane plasma treatment enhanced the hydrophobicity of this polymer—the elemental F/C ratio at the surface increased and was almost twice as big as the starting value. The water contact angle increased from 132° for virgin polyvinylidene fluoride (PVDF) to 155° after plasma treatment. Some effects of etching were observed, especially for longer plasma treatment time. 

Solid metal electrodes are usually polished mechanically and are sometimes etched with nitric acid or aqua regia. Purification of platinum group metal electrodes is effectively achieved also by means of high-frequency plasma treatment. However, electrochemical preparation of the electrode immediately prior to the measurement is generally most effective. The simplest procedure is to polarize the electrode with a series of cyclic voltammetric pulses in the potential range from the formation of the oxide layer (or from the evolution of molecular oxygen) to the potential of hydrogen evolution (Fig. 5.18F). 

It was observed elsewhere that plasma treatment of polymer macromolecules results in their cleavage, ablation, alterations of chemical structure and thus affects surface properties e.g. solubility [75]. The effects of the treatment in Ar plasma on the surface properties of PE were examined in [72]. The parameters of the plasma discharge (240 s, 8.3 W power) were chosen, on the basis of our previous experiments [70-74,78], to guarantee the most pronounced changes of polymer surface. Mean thickness of the ablated PE layer was calculated from the weight difference measured by gravimetry. By Ar plasma (8.3 W, 240 s) 30 8 nm thick surface layer is ablated and thickness of the surface layer removed from plasma-modified PE by 24 hour water etching is 21 5 nm [78]. 

Step 3 The PS particles are removed by an O2 plasma treatment (2 min at 250 W, and SOOmTorr). In Chemical Properties we present XPS results, which describe the effect of O2 plasma treatment regarding removal of the PS particles by O2 plasma and oxidation of Pt. It should be noted that it is not possible to dissolve the PS particles in acetone after the Ar+ etching process, which is believed to be due to ion-induced crosslinking of the polymer chains during ion etching (111), making them resistant to normal solvents for PS. The radial distribution function, g r), from the initial colloidal adsorption step is preserved throughout the nanofabrication procedure. 

Yasuda et al. [198-200] studied the effect of plasma treatment on different fibers and fabrics. They used four nonpolymerizing gases helium, air, nitrogen, and tetra-fluoromethane. It was found that in some cases the etching of the fiber was accompanied by the implantation of the specific atoms into its surface. The model studies performed with nylon 6 have shown that plasma treatment, similar to plasma polymerization, may be carried out in the power-deficient range as well as in the gas-deficient range. 

Pretreated (enzymatic and enzymatic-I-hydrogen peroxide) knitted wool fabrics were treated with argon and atmospheric air plasma to improve adsorption capacity (Demir et al., 2010). After plasma treatment, a chitosan solution was appUed for antimicrobial effect. The treated fabrics were evaluated in terms of washing stabiUty as well as antimicrobial activity. The surface morphology was characterized by SEM images and Fourier transform infrared (FilR) analysis. The results indicate that the atmospheric plasma treatment had an etching effect and increased the fiinctionahty of wool surface. Atmospheric plasma treatment also enhanced the adhesion of chitosan to the surface and improved the antimicrobial activity. 

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