Poreformers

Poreformers, more commonly referred to as porogens, are additives incorporated into a material precursor with the intention of generating porosity in the final product. They are used in polymers, ceramics, composites, and porous membranes to tailor pore size, connectivity, and overall porosity.

The porosity is achieved through mechanisms such as leaching (sacrificial template), gas evolution during processing, or phase separation that yields a void network when the porogen is removed. After curing or synthesis, the porogen is extracted or burned out, leaving interconnected pores.

Common porogens include soluble salts and sugars (for example sodium chloride and sucrose), waxes or paraffin, starch, gelatin, and inorganic or organic blowing agents. In membrane and foam applications, porogens are chosen to generate specific pore sizes and interconnectivity, and may be designed to be removed by washing, dissolution, or thermal degradation.

Applications span tissue engineering scaffolds, filtration membranes, catalyst supports, battery electrodes, and thermal or acoustic insulation foams. The choice of porogen affects mechanical properties, pore size distribution, permeability, and biocompatibility of the final material.

Considerations include compatibility with the matrix, processing temperatures, removal efficiency of the porogen, potential residuals, and environmental or health impacts. Porogen selection is guided by desired porosity, application, and manufacturing constraints, balancing porosity with mechanical integrity and cost.