The pore structure of macroreticular ion exchange resins

Abstract

AbstractA series of new cation and anion exchange resins differing entirely from conventional homogeneous (microreticular) gels and having a rigid macroporous structure similar to those of conventional adsorbents are characterized. These ion exchangers have been designated as macroreticular ion exchange resins. A detailed analysis is made of the pore structure of the resins including pore size distribution, surface area, and electron micrographs. From these data a model of the physical structure is presented. The relationship between the physical structure and utility of these ion exchange resins is developed for various areas of application, including catalysis, adsorption from nonpolar solvents, and the adsorption of large molecules such as peptides and proteins. The effect of hydration upon the pore structure of several of the macroreticular ion exchange resins is critically evaluated also. During the course of hydration, the gel portion hydrates first and this is followed by the filling of the macroreticular pores. From these data one is able to ascertain the pore structure not only in the anhydrous state but also in aqueous media.