Surface Wipe Techniques

Washing or wiping the skin can remove chemical deposits, and chemical concentrations can be measured (Durham and Wolfe, 1962 Davis, 1980). Wash techniques are generally used only to assess hand exposure, while wiping techniques can, in theory, be applied to other skin surfaces. 

Solvent washing of concrete surfaces is a wipe technique... 

The elements which are observed are silicon and oxygen with some carbon present on the surface and only a slight amount of the matrix stainless steel. The SIMS spectra were taken simultaneously with the ISS data and show primarily silicon and cluster peaks of silicon and oxygen together with a small amount of the matrix material. Even when the surface of the 304 stainless steel was wiped after rinsing the appeared visably clean some smut remained behind as detected by both positive SIMS and ISS. The smut was completely removed by dipping the work in hot caustic soda solution or in chromic acid solution conventionally used in the industry. The analysis of the smutted surface and the desmutted surface by a variety of techniques is shown in Table V. Each of the techniques has its strong points. In AES, for instance, both sulfur and chlorine are readily detected in... 

The simplest method for fabricating PMEs from preformed polymers is based on adsorption from solution by dipping the electrode in a polymer solution. The reproducibility of this method is questionable however because of the need to shake or wipe excess solution from the surface before the solvent evaporates. More reproducible films can be prepared by dropping a measured aliquot of a polymer solution onto the electrode surface, followed by the slow evaporation, preferably in a solvent-saturated chamber, of the solvent. For thin polymer films, the technique of spin coating can produce more homogeneous and reproducible layers. This technique involves the drop coating and solvent evaporation of the polymer solution on a rapidly rotating electrode. 

Eor fine particles, a stub is cleaned by rubbing it on a clean piece of paper. A thin layer of carbon suspension is then wiped across the surface of the stub with one smooth movement. When the carbon dries and is almost totally matt, the specimen is deposited on to the surface. The excess is shaken off, leaving the material adhering to the stub (Figure 13). If one practices with sugar, the technique has failed if the sugar adheres but has turned black. 

External antistats. External, or topical, antistats are applied to the surface of the finished plastic part through techniques such as spraying, wiping, or dipping. Since they are not subjected to the temperatures and stresses of plastic compounding, a broad range of chemistries is possible. The most common external antistatic additives are quaternary ammonium salts, or quats, applied from a water or alcohol solution. 

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