Simple adsorption isotherm
data_aif
_exptl_operator 'Jack'
_exptl_date 2024-03-12T00:00:00
_exptl_instrument 'Example Instrument'
_exptl_adsorptive 'Ar'
_exptl_temperature 87.0
_adsnt_sample_mass 0.1000
_adsnt_sample_id 'Example 1'
_adsnt_material_id 'example adsorbent'
_units_temperature 'K'
_units_pressure 'kPa'
_units_mass 'g'
_units_loading 'ml(STP) g-1'
loop_
_adsorp_pressure
_adsorp_p0
_adsorp_amount
0.00012621 101.3 0.00010258
0.00036169 101.3 0.1277
0.00051271 101.3 0.25735
...
98.643 101.3 411.91
100.63 101.3 415.18
Isotherm with hysteresis
data_aif
_exptl_operator 'Jack'
_exptl_date 2024-03-12T00:00:00
_exptl_instrument 'Example Instrument'
_exptl_adsorptive 'C2H2'
_exptl_temperature 298.0
_exptl_p0 15000
_adsnt_sample_mass 0.1025
_adsnt_sample_id 'Example 2'
_adsnt_material_id 'example adsorbent'
_units_temperature 'K'
_units_pressure 'mbar'
_units_mass 'g'
_units_loading 'cm³/g STP'
loop_
_adsorp_pressure
_adsorp_amount
1.0559467781424523 0.19411186353264537
2.1112168209085462 0.386342683156203
3.174155286300659 0.5774744895994802
...
898.9952867578124 35.96266113007714
998.8878110449218 37.472033085979824
loop_
_desorp_pressure
_desorp_amount
956.9138768876953 36.95464461103444
917.1307624174805 36.40734251067766
880.99 35.86967548657904
...
3.84981786702919 1.600418554355085
1.897280711136818 1.2070126216255774
Python interface with pyGAPS
The AIF can interface directly with other python libraries for analysis such as pyGAPS.
import pygaps.characterisation as pgc
import pygaps.parsing as pgp
isotherm = pgp.isotherm_from_aif('example1.aif')
results = pgc.area_BET(isotherm, verbose=True)BET area: a = 1273 m2/g
The BET constant is: C = 612.3
Minimum pressure point is 0.00612 and maximum is 0.0578
Statistical monolayer at: n = 0.0153 mol/g
The slope of the BET fit: s = 65.2
The intercept of the BET fit: i = 0.107
More examples
More examples can be found at https://mof-international.org/fair-practice-publishing-adsorption-data/