To deduce particle size information, the majority of particle sizing techniques assume that the particles are spheres. For industrial materials, particles are rarely spherical. Non-sphericity causes discrepancies in different measurement technologies so results vary from the real characteristics of the sample. Applications like crystallisation require .shape information in addition to the size of the particles. The majority of this thesis describes results that have demonstrated that particle shape has a strong influence on particle size distribution measured by different techniques. The effect of shape on measured particle size distribution was investigated by ultrasonic attenuation spectroscopy (VAS) compared with other widely used techniques such as laser diffraction spectroscopy (LDS), microscopic image analysis (MIA) and focused beam reflectance measurement (FBRM). A strategy was applied using different chemical systems to monitor the importance of shape to measured size distribution using different techniques; fragile and non-fragile, .sp-pericaC'crystalline and irregular materials were tested. The measurements were successfully applied to laboratory crystallisation processes of different organic and inorganic chemicals In-situ monitoring of particle size evolution during crystallisation using FBRM has aroused much interest. Therefore it was important to demonstrate the dependence of measured particle size on different operating conditions and more particularly on the hydrodynamic conditions, solvent, temperature and other physical and chemical , properties of the system. In-situ measurement of maximum supersaturation during batch crystallisation and dissolution processes of different chemical systems is presented, through which nucleation kinetics of the crystallisation was retrieved. This was clemonstrated for different organic and inorganic chemical systems using FBRM as a process analytical technique (PAT). Based on crystallisation behaviour and with process analytical techniques, notably FBRM to retrieve the nucleation kinetics, the growth kinetics of different chemical systems are presented based on seeded batch cooling crystallisation. Finally future developments within this area of research are presented.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:486872 |
| Date | January 2007 |
| Creators | Patchigolla, Kumar |
| Publisher | Heriot-Watt University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/10399/2088 |
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