Hydrophobic treatments effect

H. Nakajima, T. Konomi, and T. Kitahara. Direct water balance analysis on a polymer electrolyte fuel cell (PEFC) Effects of hydrophobic treatment and microporous layer addition to the gas diffusion layer of a PEFC on its performance during a simulated start-up operation. Journal of Power Sources 171 (2007) 457-463. 

After eight years of exposure, an extensive examination was started in 1994 to evaluate the effectivity and durability of the water repellent treatments [4]. Macroscopic tests as water uptake measurements were carried out to determine the remaining effect of the protective organosilicon layer. Due to the fact that surface information from hydrophobic treatment of mineral surfaces is supplied by surface sensitive measuring techniques, TOF-SIMS and additional DRJFT-studies on treated and exposed material were performed. 

The most important result of the plasma treatment of polymers, which are produced on an industrial scale, is the change in their wettability and adhesion characteristics. As was discussed earlier, plasma treatment can make polymers more lydrophilic as well as more hydrophobic. Both effects are widely used for practical applications. The change of wettability is usually characterized experimentally by the contact angle 9, which is formed on the solid surface along the linear solid-hquid borderline of air (see Fig. 9-25). An increase of... 

In general, it can be concluded that hydrophobic treatment of concrete is an effective and low-cost preventative measure against corrosion that may be caused by chloride ingress. The beneficial effect is mainly a strong reduction of chloride ingress, both in semi-permanent contact and in wetting/drying situations. The effective life in fully exposed atmospheric conditions is at least five years and more, probably much more, when protected from UV radiation by a layer of asphalt... 

Hydrophobic treatment of the contiguous bodies, i.e., treatment to increase the angles 31 and 34, in accordance with Eq. (IV.43) should lower the capillary pressure. This circumstance in turn, in accord with Eqs. (IV.32)-(IV.34), will lower the capillary forces. An increase in the angle 34 (hydrophobization of the substrate) will have a greater effect on the capillary forces than can be obtained by increasing the contact angle 6 1 (hydrophobization of the particles). 

Hydrophobic treatment (HT) and micro-porous layer (MPL) in addition to gas diffusion layer (GDL) effect on water balance... 

Pauthe M., Quinson J.F., Hdach H., Woignier T., Phalippou J., Scherer G.W. Autoclave treatment effect on silica alcogel texture. J. Non-Cryst. Solids, 1991 130 1-7 Pauthe M., Despetis F., Phalippou J. Hydrophobic silica CO2 aerogels. J. Non-Cryst. Solids. 1993 155 110-114... 

Nylon-11. Nylon-11 [25035-04-5] made by the polycondensation of 11-aminoundecanoic acid [2432-99-7] was first prepared by Carothers in 1935 but was first produced commercially in 1955 in France under the trade name Kilsan (167) Kilsan is a registered trademark of Elf Atochem Company. The polymer is prepared in a continuous process using phosphoric or hypophosphoric acid as a catalyst under inert atmosphere at ambient pressure. The total extractable content is low (0.5%) compared to nylon-6 (168). The polymer is hydrophobic, with a low melt point (T = 190° C), and has excellent electrical insulating properties. The effect of formic acid on the swelling behavior of nylon-11 has been studied (169), and such a treatment is claimed to produce a hard elastic fiber (170). 

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