2. PREPARATION OF CELLULOSE BEADS
The preparation of spherical cellulose beads was described for
the first time in 1951.17 The materials, then named cellulose
pellets, were simply prepared by hand-dropping a viscose
2.1. Shaping into Spherical Particles
Despite the fact that various starting polysaccharides, solvents,
and regeneration methods can be applied for the preparation of
cellulose beads, all procedures have in common the fact that the
shaping of the beads from a polysaccharide solution is either
achieved by dropping (Figure 2a−d) or dispersion techniques
(Figure 2e). This separation is reasonable since it is not only
based on technological aspects but likewise a rough macroscopic
separation into cellulose beads with a size above
(dropping techniques) or below (dispersion) 250−500 μm.