Dft Model References B - Micromeritics TRISTAR II PLUS Operator's Manual

B DFT Models
Kelvin Equation with Broekhoff-de Boer Thickness Curve
N2 - Broekhoff-de Boer Model
Geometry:
Substrate:
Category:
Method:
The kernel function is calculated using the Broekhoff-de Boer equation with standard parameters:
The nitrogen properties used in the Kelvin equation are:
Surface tension =
Molar density =
N2 - Broekhoff-de Boer Model
Geometry:
Substrate:
Category:
Method:
The calculation is similar to the above except that cylindrical geometry is assumed, and the film
thickness depends on pore size (see reference).
References:
DFT M R
ODEL EFERENCES
The papers listed below provide additional information on DFT models:
1. "Determination of Pore Size Distribution from Density Functional Theoretic Models of
Adsorption and Condensation within Porous Solids," J.P. Olivier and W.B. Conklin, Micro-
meritics Instrument Corp; presented at the International Symposium on the Effects of Sur-
face Heterogeneity in Adsorption and Catalysts on Solids, Kazimierz Dolny, Poland (July
1992).
B - 16
Cylinder
Average
Porosity
Nitrogen 77 K
8.88 dynes cm
-3
0.02887g cm
Cylinder
Average
Porosity
Nitrogen 77 K
Specifically, equations 20 and 21 in: J.C.P. Broekhoff and J.H. de Boer,
"The Surface Area in Intermediate Pores," Proceedings of the Inter-
national Symposium on Surface Area Determination, D.H. Everett, R.H.
Ottwill, eds., U.K. (1969).
-1
TriStar II Plus Operator Manual
303-42800-01 (Rev M ) — Sep 2023