Summary of real chains

Real chains have interactions between monomers. If the attraction —between monomers just balances the effect of the hard-core repulsion, the  

Such a situation with zero net excluded volume is called the -condition, corresponding to a particular i9-temperature for a given solvent. 

If the attraction between monomers is weaker than the hard-core repulsion, the excluded volume is positive and the chain swells. This corresponds to a good solvent at a temperature above the -temperature, and the coil size is larger than the ideal size  

The chain conformation is a self-avoiding walk of thermal blobs, whose size decreases as temperature is raised. 

In an athermal solvent, the monomer-solvent energetic interaction is identical to the monomer-monomer interaction. This makes the net interaction between monomers zero, leaving only the hard core repulsion between monomers. The excluded volume is independent of temperature (v Ks b ), and the chain is a self-avoiding walk of monomers  

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