Pore connectivity and hysteresis in gas adsorption: A simple three-pore model

• Different shapes and sizes of hysteresis loop have been observed for a set of pore with different sequences of connectivity.
• The adsorption in one section of the pore is affected significantly by the state of the adjacent pores.
• The presence and the position of the closed ends affect significantly the shape and size of the hysteresis loop.
• Pore size distribution calculated using kernel of isotherms of independent open pores may be incorrect for connected pores.

We present a simulation study to investigate the significance of connectivity on the adsorption isotherm, for a collection of connected pores. By examining different sequences of connectivity in a set of three cylindrical sections of different sizes, we have been able to obtain adsorption isotherms with a variety of shapes and sizes of hysteresis loop; none of which can be reproduced by combining isotherms of the individual pores with two open ends. We conclude that there is a need to re-examine the choice of kernel in the determination of pore size distributions for systems with interconnected pore spaces.

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