Surface cleaning processes

These same N(ls) peaks have also been seen on F-contaminated Si02 surfaces, albeit at different relative concentrations (which may have to do with different surface cleaning processes [10]) [15]. 

An interesting approach was adopted by Annabi-Bergaya et al. (1979), who determined methanol and isopropanol desorption isotherms on a series of charge-deficient Ca-montmorillonites (prepared from Na- and Li-saturated montmorillonite). Each desorption isotherm was determined after a surface cleaning process with the particular alcohol in order to prevent the irreversible collapse of the interlamellar space. The adsorbent was exposed to the alcohol vapour atp/p° = 0.9 and the stepwise mass... 

Code used in parentheses is indicates the surface cleaning process code used without parentheses is indicates coating process, Plasma duration in minute was used as noted in table unless otherwise specified with a superscript on the code. 

The cleaning process proceeds by one of three primary mechanisms solubilization, emulsification, and roll-up [229]. In solubilization the oily phase partitions into surfactant micelles that desorb from the solid surface and diffuse into the bulk. As mentioned above, there is a body of theoretical work on solubilization [146, 147] and numerous experimental studies by a variety of spectroscopic techniques [143-145,230]. Emulsification involves the formation and removal of an emulsion at the oil-water interface the removal step may involve hydrodynamic as well as surface chemical forces. Emulsion formation is covered in Chapter XIV. In roll-up the surfactant reduces the contact angle of the liquid soil or the surface free energy of a solid particle aiding its detachment and subsequent removal by hydrodynamic forces. Adam and Stevenson s beautiful photographs illustrate roll-up of lanoline on wood fibers [231]. In order to achieve roll-up, one requires the surface free energies for soil detachment illustrated in Fig. XIII-14 to obey... 

In dipping generally, but particularly with the anode process, it is desirable to use tanks that circulate the coagulant and latex compound, particularly the latter. Use of circulation keeps the Hquid surface clean and free from lumps, scum, or bubbles. Mechanical circulation can cause mbber particle instabihty, however, and eventually coagulate the compound. Therefore, tanks should be designed to minimize friction or shear action, and the compound stabilized to maintain mechanical stabiUty. 

For a surface treatment process to be practical, not only does it have to produce a clean, stable surface suitable for chemical or physical bonding to the... 

Aqueous solutions of acids as used in metal cleaning processes such as pickling for the removal of rust or rolling scale during the production and fabrication of metals, or in the post-service cleaning of metal surfaces. 

The typical results of poor control over an acid cleaning process are irregular pitting and a very rough and jagged appearance on the various boiler surfaces that may resemble Swiss cheese. ... 

Additionally, the surfactant properties of filmers reduce the potential for stagnant, heat-transfer-resisting films, which typically develop in a filmwise condensation process, by promoting the formation of condensate drops (dropwise condensation process) that reach critical mass and fall away to leave a bare metal surface (see Figure 11.2). This function, together with the well-known scouring effect on unwanted deposits keeps internal surfaces clean and thus improves heat-transfer efficiencies (often by 5-10%). 

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