Complex coacervation in the narrower sense

All the properties of this partial miscibility indicate that charge effects play no part in the process and that the main requisite for the occurrence of coacervation is a water deficit in the total system (see summary, left hand column). This example is furthermore especially interestit because another type of coacervation is also possible in mixtures of gelatin and gum arabic, the so-called complex coacervation (in the narrower sense). 

Fig. 36. Reversal of charge, beginning and end of the coacervation or flocculation range as a function of the colloid concentration Ca. a in the complex coacervation in the narrow sense, (see p. 338, 2). b in the coacervation of gum arabic with hexol nitrate (see also p. 388). c in the coacervation or flocculation of gum arabic or an other acidoid with lower valent cations. (see p. 392).

Although the theory of complex coacervation in the narrower sense (p. 370 2o) was originally developed on the basis of the assumption that sols are in principle two phase systems, good reasons were present for assuming that a theory which is based on the representation of the biocolloid sols as true solutions would contain a greater element of truth. 

This latter representation had been based on the fact that it is not only possible to replace one of the two colloids by a suitably chosen micro ion ( crystalloid ion) of the same sign of charge while retaining the typical properties of complex coacervation in the narrower sense ( 3) but also and especially, on the fact that we have... 

Thus when one accepts point of view 1. for the variants colloid cation -h micro anion and colloid anion + micro cation there is, on account of the very great similarity, no reason for doubting that it also holds for the variant colloid cation + colloid anion (i. e. for the complex coacervation in the narrower sense). 

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