Control of Pore Structure in Polymeric Monoliths Prepared from Colloidal Dispersions

Reliable control of pore size distribution in porous materials is a key feature for addressing specific applications. The reactive gelation process represents a robust and efficient method to obtain mechanically stable monoliths with tunable pore size distribution. Primary polymer nanoparticles are destabilized and aggregated in a controlled way, forming a percolating gel. Afterward, this structure is hardened by a postpolymerization, carried out through heating. Different parameters play a major role in determining the final morphology of the monolith. In this work, the effect of primary particle architecture (i.e., core-to-shell ratio) and initial solid content of the latex is investigated, using two different sizes of nanoparticles. Actually, the first parameter affects the pores in the small range (0.01-1 mu m) whereas the latter those in the larger one (1 mu m to several micrometers), independently of the primary particle size. As a result, monoliths with very well-defined pore size distributions are obtained.