Non-equilibrium dynamics of glass-forming liquid mixtures
- Instituto de Física “Manuel Sandoval Vallarta,” Universidad Autónoma de San Luis Potosí, Álvaro Obregón 64, 78000 San Luis Potosí, SLP (Mexico)
The non-equilibrium self-consistent generalized Langevin equation theory of irreversible processes in glass-forming liquids [P. Ramírez-González and M. Medina-Noyola, Phys. Rev. E 82, 061503 (2010)] is extended here to multi-component systems. The resulting theory describes the statistical properties of the instantaneous local particle concentration profiles n{sub α}(r, t) of species α in terms of the coupled time-evolution equations for the mean value n{sup ¯}{sub α}(r,t) and for the covariance σ{sub αβ}(r,r{sup ′};t)≡δn{sub α}(r,t)δn{sub β}(r{sup ′},t){sup ¯} of the fluctuations δn{sub α}(r,t)=n{sub α}(r,t)−n{sup ¯}{sub α}(r,t). As in the monocomponent case, these two coarse-grained equations involve a local mobility function b{sub α}(r, t) for each species, written in terms of the memory function of the two-time correlation function C{sub αβ}(r,r{sup ′};t,t{sup ′})≡δn{sub α}(r,t)δn{sub β}(r{sup ′},t{sup ′}){sup ¯}. If the system is constrained to remain spatially uniform and subjected to a non-equilibrium preparation protocol described by a given temperature and composition change program T(t) and n{sup ¯}{sub α}(t), these equations predict the irreversible structural relaxation of the partial static structure factors S{sub αβ}(k; t) and of the (collective and self) intermediate scattering functions F{sub αβ}(k, τ; t) and F{sub αβ}{sup S}(k,τ;t). We illustrate the applicability of the resulting theory with two examples involving simple model mixtures subjected to an instantaneous temperature quench: an electroneutral binary mixture of equally sized and oppositely charged hard-spheres, and a binary mixture of soft-spheres of moderate size-asymmetry.
- OSTI ID:
- 22420070
- Journal Information:
- Journal of Chemical Physics, Vol. 140, Issue 23; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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