End-functionalized polymer as a tool to determine the pore size and the interaction parameters in liquid chromatography

We present a general relation between the polymer excess in depletion (or adsorption) layers near a solid surface and the partition coefficient for distributing the polymer over a system of wide pores and a bulk solution. Using this relation, an analytical theory of liquid chromatography of polymers with and without specific end groups is constructed. This theory can be applied to size exclusion chromatography (SEC), critical chromatography (CC), and adsorption chromatography (AC). The dependence of the retention volume of non-, mono-, and difunctional polymers on molar mass, pore width, and two polymer-surface interaction parameters is analyzed. One such interaction parameter applies to the main-chain units of the polymer, the other to the end groups. Several procedures to obtain these interaction parameters from experimental data are described. It is shown that experiments with well-defined nonfunctional, monofunctional, and difunctional polymers enable the determination of the surface area of porous and nonporous materials.