Continuous hydrothermal synthesis of inorganic nanoparticles
In Chapter 1, the special properties of nanoparticles are discussed, followed by different methods of nanoparticle synthesis, particularly the hydrothermal flow synthesis. Finally, factors thought to affect particle size are identified, and the aims of the Thesis are stated. In Chapter 2, hydrothermal flow reactors used by different research groups are discussed. Modelling of the reactor mixing point leads to a new nozzle design, to improve mixing and avoid blockages, which is incorporated into the Nottingham reactor. In Chapter 3, it is explained how initial problems of reactor blocking are solved, and that formation of CuO is seen to be affected by reaction temperature and which precursor is used. Chapter 4 details how Ru02 and anatase Ti02 are made separately, and unsuccessful attempts are made to produce rutile Ti02 and a single-phase mixed-metal (Ru-Ti) oxide compound. Chapter 5 describes how an efficient method of separating CexZr1-x02 particles from suspension was found. This allowed the identification of a dependence of particle size upon reaction temperature. In Chapter 6, the effect of increasing temperature upon formation of α-Fe203 particles was investigated, and found to give larger particles and greater yields. Particles with different size distributions were then used as catalyst for the growth of carbon nanofibres, leading to the formation of different nanofibre structures. Chapter 7 reports how successful preliminary experiments were made to form Ag and CdS nanoparticles using the hydrothermal flow method. Finally, in Chapter 8, the achievements of this Thesis are summarised and ideas are put forward for future work.