Analysis of micropores the MP method

In this method, micropores are considered to Fill by the growing together of the adsorbed films on opposing pore walls [84]. The thickness of the films is obtained from a t curve derived from measurements of adsorption on non-porous solids. 

The micropore isotherm looks very similar to the Type 1 Langmuir isotherm since adsorption is limited to the few layers that can adsorb within the pores and, when these are filled, there is very little external surface remaining [85]. 

One then proceeds in a similar manner to the second pore group with t between 0.3678 and 0.4369 ran. The analysis continues until there is no iiirther decrease in the Vc-t slope which means no further blocking of pores by multilayer adsoiption. The pore volume distribution curve is shown in Hgure 3.18. 

In Table 3.4, column 2 gives the volume adsorbed at relative pressures given in column 1 e thickness of the adsorbed layer (t) is derived from equation 3.29 the condensed volume from equation 3.34 the cumulative specific surface from the slope of the. va versus t curve, equation 3.32, Rgure 3.17 the pore volume from equation 3.61 and the hydraulic radius from equation 3.41. 

The MP method is based on the use of the appropriate t curve the choice is far more important in the micropore region than in the mesopore since, in this low pressure region, the heats of adsorption affect the fllm thickness strongly. Far more important than this, the t values constitute the total pore radius, whereas in the mesopore region they appear only as a correction term. 

---