Dispersing agents, analysis

An experimental problem is to obtain adequate dispersion of the particles before sedimentation analysis. For powders that are difficult to disperse the addition of dispersing agents is necessary, together with mtrasonic probing. It is essential to examine a saiTmle of the dispersion under a microscope to ensure that the sample is fully dispersed. 

Effective dispersion of the particles is an essential prerequisite for all methods of sedimentation analysis. It is often necessary not only to stir the suspension vigorously prior to analysis, but to introduce the powder already mixed with a dispersing agent. A further agent to prevent flocculation may be needed, and it may be necessary to adjust the pH of the suspension to a suitable value determined by experiment... 

In the area of process monitoring TLC has been used for the study of the thermal decomposition of zinc di-isopropyl dithiophosphate (antiwear additive in lubricating oils) [458]. TLC analysis has been reported as a quality control tool for analysis of dispersing agents (alkylsalicylates, thioalkylphenolates), AOs (dithiophosphates, dialkyldithiophosphates) and their intermediates in lubricating oil (UV detection,... 

Use Production of aluminum, manufacture of abrasives, refractories, ceramics, electrical insulators, catalyst and catalyst supports, paper, spark plugs, crucibles and laboratory wares, adsorbent for gases and water vapors (see alumina, activated), chromatographic analysis, fluxes, lightbulbs, artificial gems, heat-resistant fibers, food additive (dispersing agent). 

More recent reviews on this particular topic suggest that MSPD has attracted many researchers in environmental, clinical, and food analysis. Different bulk materials have been used as matrix dispersing agents the most popular is C18- and C8-bonded silica. 

Bernhardt C (1988) Preparation of suspensions for particle-size analysis—methodical recommendations, liquids and dispersing agents. Adv Colloid Inter Sci 29 79-139... 

Type of CNT Dispersing agent Solvent Optimum CNT concentration (mg mi" ) Procedure Redox probes/EQ analysis performed Applications References... 

The surface of FW200 carbon black exhibited an electron acceptor (acidic) characteristics. On the other hand, the N550 showed electron donor (basic) character which was reflected by the zeta potential analysis. The addition of dispersing agents changed the character of filler s surface as shown in Figure 3. 

On the plantations, the Hevea trees are tapped , i.e., the bark is cut and the latex which flows is collected in small cups. The latex is a stable dispersion of rubber in water, proteinous material being the dispersing agent a typical analysis might be as follows ... 

Even though the combined effect of noise and ototoxic substances was not proved, this effect should be considered. According to Santos (2013), the effect is synergic. That s way some prevention measures are recommended namely, the replacement of a solvent by another which does not have ototoxic substances in its composition. The quantification of the occupational exposure to chemical agents and the analysis of the possibility of dispersion agents by the adjacent sections should also be analysed. 

Certain hydrodynamical problems, as well as mass-transfer problems in the presence of surface-active agents, have been investigated theoretically under steady-state conditions (L3, L4, L10, R9). However, if we take into account the fact that in gas-liquid dispersions, the nonstationary term must appear in the equation of mass- or heat-transfer, it becomes apparent that an exact analysis is possible if a mixing-contacting mechanism is adopted instead of a theoretical streamline flow around a single bubble sphere. 

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