Model calculation of the pore-size and porosity dependences of bulk moduli in nanoporous materials

The bulk moduli of nanoporous materials are studied theoretically on the basis of an interatomic potential. We consider model nanoporous materials in which nanometer-sized cubic-shaped pores are periodically arranged in the fcc lattice. The pore-size and porosity dependences of bulk modulus are calculated exactly for the model nanoporous materials. It is shown that the bulk moduli of model nanoporous materials decrease moderately with increasing porosity. If nanoporous materials of the same porosity are compared, the bulk modulus increases and becomes constant with increasing pore-size. It is suggested from the calculation results that nanoporous materials without defects have higher bulk moduli than materials having micrometer-sized pores.