Phase Behaviour and the Chain Overlap in Good Solvents

1 Phase Behaviour and the Chain Overlap in Good Solvents 

In this section alone, in order to avoid confusion the intrinsic viscosity [rf] represents that of a particle and is dimensionless and the intrinsic viscosity [rj] represents that of a polymer and has units of gem-3. From these expressions we know that as we increase the volume fraction above each of these values, the product demarcates the structural transition. For particles there are many situations where it is relatively easy to determine the volume fraction, but for polymers the situation is more complex and it is most convenient to use a mass concentration. We can rewrite this relationship in terms of the mass of added particles in gem-3  

Here M is the mass of a mole of colloids, representing their molecular weight, and a is their radius. Now let us turn our attention to a polymer coil. The viscosity-concentration dependence of dilute polymers can be 

This simple hard sphere comparison illustrates the relationship 

So if we increase the molecular weight of the polymer then the number of links increases in direct proportion or 

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