Sphere anisotropic growth

In addition to the standard model systems described above, more exotic particles have been prepared with certain unusual properties, of which we will mention a few. For instance, using seeded growth techniques, particles have been developed with a silica shell which sttrrotmds a core of a different composition, such as particles with magnetic [12], fluorescent [13] or gold cores [14]. Another example is that of spheres of polytetrafluoroethylene (PTFE), which are optically anisotropic because the core is crystalline [15]. 

Table A.3.1. Instantaneous nucleation and anisotropic slow growth on spheres with inward development...

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