Good solvent
= Good solvent
A <good solvent> favors contact with <polymer> segments strongly enough that the effective <excluded volume> is positive. A long dilute flexible chain swells relative to an <ideal chain>; the three-dimensional size exponent is approximately $0.588$, often replaced by $3/5$ in a scaling estimate. This designation depends on the polymer, solvent and <temperature>, rather than on the solvent alone.