Preparation of porous materials with controlled pore size and porosity

Well-defined porous ceramics with controllable pore size and porosity were fabricated via a hetero-coagulation of template/ceramic particle colloidal processing. Monodispersed polymer spheres were used as template and ceramic nanoparticles as inorganic building blocks to create porous structures. The preparation of well-dispersed suspensions of polymers and ceramics is essential for the fabrication of uniformly porous materials. Core–shell composites of polymer/ceramic could be obtained by mixing the oppositely charged two suspensions via electrostatic attraction following by filtration and calcination to produce macroporous ceramic materials. SEM images and pore size distribution results revealed that various materials, such as Al2O3, TiO2 and ZrO2, with ordered and uniform macropores have been obtained by this simple procedure. The pore size could be controlled readily by varying the polymer size and the porosity could be manipulated by modifying the volume ratio of polymer/ceramic particles.