ABSTRACT
Colloidal particles are either found in nature or synthesized by humans for a great variety of purposes. Figures 2.1 through 2.5 show some examples of synthetic colloidal particles. In Figure 2.1a and b, examples of iron oxide particles synthesized to study colloid properties are shown; note the different geometries that are related to their crystalline structures and, to some extent, can be tuned through the synthetic procedure. Figure 2.2 shows typical spherical polymeric particles (Sevonkaev et al. 2010). These examples are of relatively large particles; Figure 2.3 shows thymine-functionalized gold nanoparticles of approximately 7 nm average diameter (Zhou et al. 2007). Figure 2.4 also shows gold nanoparticles, but with different sizes and shapes as a result of a different, biodirected synthesis procedure (Philip 2009). Finally, Figure 2.5 shows cobalt nanoparticles arranged in nanowires by covering with polystyrene and heating to further polymerize (Keng et al. 2009).
