The nature of thermodynamically unfavourable interactions

Thermodynamically unfavourable interactions are ubiquitous in mixed biopolymer systems. As described in chapters 3 and 5, they arise mainly from excluded volume effects — the physical volume of one biopolymer molecule is inaccessible to other biopolymer molecules — and also from electrostatic repulsion between like-charged groups on different molecules (Ogston, 1970 Nagasawa and Takahashi, 1972 Tanford, 1961). 

We can compare experimentally measured values of the cross second virial coefficient (Ay ) with theoretical ones (Ay exc) based on the contri- 

---

Once an emulsion has been formed, its stability with respect to depletion flocculation is determined primarily by the nature of thermodynamically unfavourable interactions (Ay > 0) between the biopolymers which influences the osmotic pressure in the aqueous phase according to equation (3.9) (see also equation (3.19)). That is, the value of A, influences the depth of the minimum in the depletion potential, AGdep (see equation (3.41) and Figure 3.6). 

---