Density scaling in viscous systems near the glass transition

作者：Grzybowski A^*; Grzybowska K; Paluch M; Swiety A; Koperwas K

来源：Physical Review E, 2011, 83(4): 041505.

DOI：10.1103/PhysRevE.83.041505

In this paper, a general equation of state (EOS) valid for fluids in the vicinity of the glass transition is derived on the basis of its isothermal precursor. This EOS is able to predict the density scaling of both isobaric and isothermal PVT data and it explicitly involves the scaling exponent gamma(EOS), which is most likely straightforwardly related to the exponent of the inverse power law of some effective potential valid for viscous systems. This EOS and the density scaling are very successfully tested for representatives of several material classes (van der Waals liquids, polymer melts, ionic liquids, and even strongly hydrogen-bonded systems). Additionally, if the thermodynamic scaling of primary relaxation times can be achieved with the scaling exponent gamma for a given material, then the value gamma(EOS) found from fitting its PVT data to the EOS enables us to evaluate the value gamma, which is always considerably smaller than gamma(EOS).

• 出版日期2011-4-26