Micromeritics Gemini VII 2390a, Operator'S Manual

Page: 314 / 426

Appendix C Gemini VII
C-20 239-42828-01 - Dec 2012
where:
D
A
= molecular diameter (Å) from the Horvath-Kawazoe Physical Properties
dialog
D
S
= diameter of sample atom (Å) from the Horvath-Kawazoe Physical dialog

L = pore width (nucleus to nucleus) (Å)
P = equilibrium pressure (mmHg)
Po = saturation pressure (mmHg)
IP = interaction parameter (10
-43
ergs-cm
4
) from the Horvath-Kawazoe Report
Options dialog
Cylinder Pore Geometry (Saito/Foley)
P
Po
-------
 
 
ln
3
4
---

K
RT
-------
IP
10
32
JA
4
/
J cm
4

d
0
4
---------------------------------------------------

1
k
1 +
------------ 1
d
0
r
p
-----
–
 
 
2
k
21
32
------

k
d
0
r
p
-----
 
 
10

k
d
0
r
p
-----
 
 
4
–
 
 
 

k
0 =



=
When you use the Saito-Foley
10
method, the following equation is solved for each value of P. The
value of L is determined when the solved-for relative pressure is within 0.1% of the collected absolute
pressure.
where
K = Avogadro’s number (6.023 x 10
23
)
R = gas constant (8.31441 x 10
7
ergs/mole K)
T = analysis bath temperature (K), from an entered or calculated
value on the Po and Temperature Options dialog
L = pore width (nucleus to nucleus) (Å)
P = equilibrium pressure (mmHg)
Po = saturation pressure (mmHg)
IP = interaction parameter (10
-43
ergs-cm
4
) from the Horvath-Kawazoe Report
Options dialog
d
0
=
where:
D
A
= molecular diameter (Å) from the Horvath-Kawazoe Physical Properties
dialog
D
S
= diameter of sample atom (Å) from the Horvath-Kawazoe Physical dialog

k
=

k
=
r
p
= radius of the cylindrical pore,
D
A
D
S
A
 
+
2
-----------------------------
4.5 –
k
–
k
--------------------
 
 
2

k
1 –
,

0
1.0 =
1.5 –
k
–
k
--------------------
 
 
2

k
1 –
,

0
1.0 =
L
2
---