The interaction between solid surfaces was evaluated by scanning probe microscopy using a colloidal probe. The dispersant
provided a repulsive force between the solid surfaces at less than 30 nm. On the other hand, the binder provided a bridging
force between the solid surfaces for retraction at less than 500 nm. Because of the complicated nature of the forces acting between
the surfaces, the separation distance between ceramic particles (SDP) was calculated. Moreover, the relation between the
agglomeration/dispersion of Al2
O3
particles and the calculated SDP were discussed. As an extension of these results, Al2
O3
pastes
were prepared for tape casting from a viewpoint of the SDP. The tape casting of nanoparticles, which is generally difficult, was
successful. On the basis of these fundamental studies applied to environmental functional materials, porous ceramics having
oriented pores were prepared by an extrusion method. The obtained porous ceramics demonstrate high capillary action and are
used for the relaxation of an urban heat island. Porous ceramics having nano-sized pores were prepared by a slip casting method.
The porous filter has CO2 gas separation ability by using surface diffusion.