Wedge-type pore

The type B hysteresis curve is associated with slit-shaped pores or the space between parallel plates. Type C hysteresis is produced by a mixture of tapered or wedge-shaped pores with open ends. Type D curves are also produced by tapered or wedge-shaped pores but with narrow necks at one or both open ends. Type E hysteresis results from McBain s bottleneck pores. In pores of this shape, emptying of the wide portion will be delayed during desorption until the narrow neck can evaporate. Therefore, the desorption curve exhibits a small slope at high relative pressures and a large slope where the wide part of the pore empties. 

Type C. Adsorption branch zooms in the middle p/po zone, while desorption branch grows slowly. It is a typical lag ring formed from uneven distributed pores. Cone-shaped or double cone-shaped capillary pores, and wedge pores are closed at sides and opening at both ends belong to this type. The C-ring is very rare. 

Type A. Both adsorption and desorption branches are steep at intermediate relative pressures. This type of isotherm is designated Type HI by x lUPAC [8]. These include tubular capillaries open at both ends tubular capillaries with slightly wider parts tubular capillaries of two main dimensions wide ink bottle jrares provided f/t < w < 2r tubular capillaries with one narrow part wedge shaped capillaries. lUPAC state that Type HI can te associated with agglomerates or compacts of uniform spheres in fairly regular array and hence to a narrow distribution of pore sizes. 

Type C. The adsorption branch is steep, at intermediate pressures the desorption branch is sloping. These are typical of a heterogeneous distribution of pores of some of the following shapes tapered or double tapered capillaries and wedge formed capillaries with closed sides and open ends. 

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