Pore-nucleation phenomena

Abstract A simplified quintuple model for the description of freezing and thawing processes in gas and liquid saturated porous materials is investigated by using a continuum mechanical approach based on the Theory of Porous Media (TPM). The porous solid consists of two phases, namely a granular or structured porous matrix and an ice phase. The liquid phase is divided in bulk water in the macro pores and gel water in the micro pores. In contrast to the bulk water the gel water is substantially affected by the surface of the solid. This phenomenon is already apparent by the fact that this water is frozen by homogeneous nucleation. 

We have mapped the translocation process to a nucleation and growth phenomenon, characterized by a free energy barrier. The principal source of this free energy barrier is conformational entropy of the polymer. Additional contributions to the overall free energy landscape arise from solvent conditions, polymer-pore interactions, geometry of the pore, and the electrochemical potential gradient driving the whole process. 

---