Vitreous carbon spheres

A typical process for the production of vitreous-carbon spheres is represented schematicctlly in Fig. 6.9.1 The precursor is a partially polymerized polymer such as furfuryl alcohol, catalyzed with p-toiuene sulfonic acid and mixed with acetone to obtain the proper viscosity for atomization.l l A pore former is added which can be an organic material with a high boiling point or sub-micron solid particles such as carbon black. Atomization occurs in the thermal reactor shown schematically in Fig. 6.10.1 The curing time is very brief because of the small size of the particles ( 45jum). 

Catalytic Support. Vitreous carbon spheres are being considered as catalyst supports for iron and other metals. The material may offer some important advantages over other forms of carbon, such as lower inorganic impurities (which may poison the catalyst) and a more uniform pore structure. The activation mechanism and the properties and characteristics of catalytic materials are reviewed in greater detail in Ch. 10, Sec. 4.0. 

Rgure 6.9. Processing flow-chart for vitreous carbon spheres.h l... 

Vitreous carbon can be produced in three basic types which have essentially the same microstructure, but different macrostructures solid (or monolithic), foam (or reticulated), and spheres (or particles). Each type is reviewed in the next three sections. 

---