Experimental investigations of binary mixtures

The number of monomers in a two-dimensional thermal blob is smaller than in the three-dimensional thermal blob. 

The chains in a monodisperse two-dimensional melt are roughly the size of a thermal blob and are therefore barely ideal. The number of the other chains in a pervaded area of a given chain is the product of this area Nb and the two-dimensional number density of chains 1 jNb and is of the order of unity (Pss 1). Thus, chains do not significantly interpenetrate each other in two dimensions. This is the expected result whenever the fractal dimension of the object and the dimension of space are the same. 

This fluctuation corresponds to a transfer of A monomers from the rest of the blend into the small volume with a concurrent transfer of the same number of B monomers out of the small volume (an effective exchange of A and B monomers)  

The free energy of mixing in this small volume Aiv powers of this fluctuation 60  

The term linear in 60 can be rewritten in terms of the number of monomers exchanged  

---