Processes and Techniques for Droplet Generation

In this chapter, various processes and techniques for droplet generation are described in detail, along with their applications and associated materials systems. 

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This section describes the atomization processes and techniques for droplet generation of normal liquids. A comparison of the features of various atomization techniques is summarized in Table... 

With the development of the TSP interface for LC-MS (Ch. 4.7), Vestal et al. [4, 16-18] also introduced a new ioiuzation technique. While the analyte ionization in their first experiments was initiated by electrons from a filament, they subsequently demonstrated that collision of the vapour-droplet beam from the TSP nebulizer with a nickel-plated copper plate leads to soft ioiuzation of analytes. Next, the collision was found not to be a vital step in the process [18]. The presence of a volatile buffer or acid in the mobile phase appeared more important in TSP, i.e., in charging the droplets generated by TSP, and in generation of preformed ions in solution. The ionization phenomena were explained in terms of the ion evaporation (lEV) model [4]. 

The fields of applications of droplet stream generators are predominantly research and development [43—48]. They are typically used for investigations of transport phenomena with liquid drops, where the good control of the drop size provides a means to adjust initial or boundary conditions of the process. Examples are evaporation of droplets and their transport in gas flows. In the development of new sizing techniques for liquid droplets, the availability of a calibration or validation standard is essential. Drop stream generators were important experimental means for verifying... 

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