Zonyl Fluorinated surfactant

The surface tensions of Zonyl fluorinated surfactants [48] are shown in Table 4.4. 

Table 4.4 Surface Tension of Zonyl Fluorinated Surfactants, Rf = F(CF2CF2)3- ...

The surface tension of Zonyl fluorinated surfactants, featuring the hydrophobe F(CF2CF2)3-gCH2CH2—, in acids and alkali is shown in Table 4.8. Anionic, cationic, nonionic, or amphoteric surfactants listed in Table 4.8 can lower the surface tension of 10% potassium hydroxide, 25% sulfuric acid, 37% hy-... 

Table 4.8 Surface Tension (mN/m) of Zonyl Fluorinated Surfactants at 25°C (77°F)...

Fig. 4.43 Surface tensions of three Zonyl fluorinated surfactants in water at 25°C. (From Ref. 48.)...

The structures and surface tensions of some Fluorad fluorinated surfactants, produced by electrochemical fluorination, are shown in Table 8.1. 3M has discontinued the production of Flourad fluorinated surfactants based on perfluo-rooctanesulfonic and perfluorooctanesulfonic acid (see Chapter 10). The structures and surface tensions of Zonyl fluorinated surfactants, produced by telomer-ization. are shown in Table 4.4. 

Fig. 4.28 Effect of surfactant concentration on the dynamic surface tension of aqueous solutions of an anionic fluorinated surfactant Zonyl FSA. (From Ref. 76. Reproduced by permission of Elsevier Science Publishers.)...

A mixture of Zonyl FSN, a nonionic fluorinated surfactant, and Tergitol NP-10, a nonionic hydrocarbon-type surfactant (nonylphenol with 10 oxyethylene units Union Carbide Corp.), exhibited surface tension synergism (Fig. 4.29). The dynamic surface tension of the 1 1 mixture is lower than the dynamic surface tension of the individual components. 

The adsorption of fluorinated surfactants on coal was investigated by Lai and Gray [52] by measuring the contact angles, the spreading coefficient, and the effect of the fluorinated surfactant on flotation. The fluorinated surfactants used were Zonyl FSN (nonionic), Zonyl FSC (cationic), Zonyl FSK (amphoteric), and Zonyl FSA (anionic). The contact angle of water on coal is about 38°-42°. The anionic fluorinated surfactant increased the contact angle to 80°-90°. The other fluorinated surfactants were less effective. The adsorption of the fluorinated surfac-... 

The adsorption of fluorinated surfactants at the electrode-solution boundary is of considerable practical interest for the application in electrochemical systems [60-64) (see Chapter 8). The electrochemical behavior of Zonyl FSN (nonionic), Zonyl FSD (cationic), Zonyl FSA (anionic), Fluorad FC-99 (anionic), and Fluorad FC-135 (cationic) at Hg and Pt electrodes has been investigated by using cyclic voltammetry and interfacial differential capacitance measurements. When the electrode is relatively hydrophobic, such as Hg, and the surface charge density is relatively low, the fluorinated surfactants, as well as hydrocarbon surfactants, are adsorbed with their hydrophobic segments oriented toward the electrode. The interaction of fluorinated surfactants with the Hg electrode is weaker and the adsorbed layer is less compact than those of hydrocarbon surfactants. When the electrode is more hydrophilic, such as Pt, or the surface charge density is high, the surfactants adsorb with their hydrophilic end group toward the electrode surface. 

The foaming properties of fluorinated surfactants vary widely (see Section 4.9). For example, amphoteric surfactants, Zonyl FSK and Zonyl FSC, are outstanding foaming agents. In contrast, the anionic fluorinated surfactant, Zonyl FSP, and the nonionic fluorinated surfactant, Zonyl FSN, are low foaming. In some systems, Zonyl FSP can function as an antifoam agent. 

Fluorinated surfactants are available as liquids, pastes, or solids. Some are diluted with water or an organic solvent some are sold in the 100% active ingredient form. If the system cannot tolerate water, an undiluted fluorinated surfactant or a surfactant formulated as an organic solution has to be used. Some nonionic fluorinated surfactants, (e.g., Fluorad FC-430, Zonyl FSN-100, and Zonyl FSO-100) are soluble in several nonaqueous solvents. Generally, the surfactant must be soluble to be effective. Hence, solubility of the surfactant may limit its use in some systems. 

Fluorinated surfactants are used in solvent-based adhesives (e.g., Zonyl FSN-100 and FSO-lOO) or in water-based adhesives (e.g., Zonyl FSA, FSP, and FSN). Fluorinated surfactants added to water-based adhesives facilitate wetting and penetration of the substrates being joined [1]. By improving leveling and spreading, fluorinated surfactants assure a complete contact between the joining surfaces and retard foaming. 

Ruorinated surfactants should be evaluated at 0.(X)1%, 0.01%, and 0.1% solids on weight of the formulated adhesive, as the effectiveness of fluorinated surfactants can vary significantly over this range. Anionic fluorinated surfactants (e.g., Zonyl FSA and FSP) should be evaluated in soft water. If hard water is used, a chelating agent should be added to reduce water hardness. 

Fluorinated surfactants (e.g., Zonyl FSN, Zonyl FSP, or Zonyl FSA) are used in cleaning formulations for removing calcium sulfate scale from reverse osmosis membranes [34]. 

In printed circuit manufacturing, a metal film, typically copper, is coated with a photoresist film and etched with gaseous NOo or aqueous nitric acid. A fluorinated surfactant (e.g.. Zonyl FSP) helps to remove copper from the circuit zone without underetching [130]. 

Fluorinated surfactants are useful in nitrogen flotation to recover uranium. The fluorinated surfactant improves separation of uranium contained in sodium carbonate and/or sodium bicarbonate solutions. In one example, Zonyl FSP yielded 95.5% recovery, as compared with 23.6% using sodium dodecyl sulfate [1]. 

Fluorinated surfactants usually differ widely in their foaming power (see Section 4.9). Cationic fluorinated surfactants and amphoteric fluorinated surfactants (e.g., Zonyl FSK) are foaming agents in aqueous media. On the other hand, nonionics (e.g., Zonyl FSN and Zonyl FSO) are low-foaming surfactants [1]. Endcapping reduces foaming. 

Anionic, cationic, and nonionic fluorinated surfactants are used in various metal treatment processes. Metal surfaces are treated to prevent corrosion, reduce mechanical wear, or enhance the aesthetic appearance. Fluorinated surfactants are used in the phosphating process for aluminum and in bright dips for copper and brass. Some fluorinated surfactants (e.g., the anionic surfactants Zonyl FSA and Zonyl FSP) are strongly adsorbed on metals and provide water and solvent repel-lency [1]. 

An amphoteric fluorinated surfactant, Du Font s Zonyl FSB, has been used as a calibration standard for high-resolution FAB-MS measurements [94],... 

Zonyl TBS is a moderate skin in itant. In contrast, the anionic fluorinated surfactant Zonyl FSA with a —CH2CH2COOLi group is neither a skin irritant nor an eye imtant and is not a skin sensitizer. However, it is a good practice to avoid skin or eye contact with commercial-grade fluorinated surfactants and flush the contaminated skin area with water, should a contact occur. 

Fig. 10.4 Organofluorine concentration in rat blood as a logarithmic function of fluorinated surfactant (Zonyl TBS) concentration in air inhaled during exposure 0, 2, and 6 weeks of postexposure time. (From Ref. 29. Reproduced by permission of Carl Hanser Verlag.)...

The elimination of fluorocompounds from the body is usually assumed to be a first-order kinetic process. The half-life of a fluorocompound in the blood or body is used to characterize retention [5,35,36]. However, the first-order elimination plot for Zonyl TBS exhibited curvature, suggesting a departure from uncomplicated kinetics (Fig. 10.6). The elimination of fluorinated surfactants from blood can be viewed as a first-order process with a postexposure time, t, dependent rate constant, /T, ... 

The elimination kinetics may be complicated by the heterogeneous composition of the fluorinated surfactant. Zonyl TBS is a mixture of fluorinated surfactants differing in their chain length and, conceivably, in their diffusion rate. The elimination kinetics of fluorinated surfactants from blood are also complicated by... 

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