The Entropic Mechanism of Water Solvation by Polymers

Abstract

Mathematical analysis of isotherms of the equilibrium water absorption of polymers displays their consistency with the equation for the theory of volume-centred filling of micropores, regardless of the hydrophilicity of the polymers. The structure of a microporous adsorbent, absent in the initial state, is formed in consequence of the reorganization of chains of a molecular-chain sponge during absorption. Thus, some chain units combine to isolate water molecules as clusters, and another part is redistributed around the clusters as a fringe that stabilizes the system by increasing the configurational entropy.