Non-local density functional theory (NLDFT) models are used to determine the porosity of a sample – pore size and pore size distribution – from measured gas adsorption isotherms. Here we provide simple, easy to understand answers to frequently asked questions relating to this topic, supplying the background understanding needed for effective application of this powerful mathematical tool.

Click Here to Learn More

 

 

 

 

 

 

DFT MODELS – The table below lists the NLDFT models currently available.  Those with asterisks (*) were included in the software shipped with Micromeritics’ 3Flex, ASAP series, TriStar 3030, Gemini 2390 and MicroActive.  The other models can be downloaded and incorporated with those already in your NLDFT model library.

The theoretical works upon which each model is based is referenced by a number corresponding to a publication listed in the DFT Model References page.

New models will be added to this list on a regular basis.  Please contact us if you have a suggestion for a new model.

 

                                                                                       

NLDFT  Model Table

 

 

Model # 225 N2@77, Carbon Cylinder Pores, SWNT, NLDFT 01/06/2011
Model # 226 N2@77, Carbon Cylinder Pores, MWNT, NLDFT  01/06/2011
Model # 227 [email protected], Carbon Cylinder Pores, SWNT, NLDFT 01/06/2011
Model # 228 [email protected], Carbon Cylinder Pores, MWNT, NLDFT 01/06/2011
Model # 229 [email protected], Zeolites H-Form, NLDFT 01/06/2011
Model # 230 [email protected], Zeolites Me-Form, NLDFT 01/06/2011
Model # 250 C[email protected] Slit Pores, 10 atm,NLDFT 04/09/2017
Model # 251 [email protected], H-Form, NLDFT 04/09/2017
Model # 252  [email protected], Me-Form, NLDFT 04/09/2017
Model # 255 HS-2D-NLDFT, Carbon, N2, 77 04/09/2017
Model # 410 HS-2D-NLDFT, Carbon, O2, 77 (Reference) 03/20/2019
Model # 420 HS-2D-NLDFT, Carbon, Ar, 87 (Reference) 03/20/2019
Model # 600 MOF1-Ar Cylindrical Mesopores, 2D-NLDFT (Reference) 03/20/2019
Model # 610 HS-2D-NLDFT, Cylindrical Oxide, Ar, 87 (Reference) 03/20/2019

 

 

Material Fluid, Temp Adsorbent Model Molecular  Theory and References Application
Carbon Ar, 77K Infinite Slit NLDFT

[2, 3]

PSD of carbon microporous and mesoporous materials with pores from 3.5 to 120 Å. Assumption: Infinit slit pore model. This model can be applied to adsorption data measured up to saturation/sublimation pressure (203 torr)
Carbon N2, 87K Infinite Slit NLDFT

[2, 3]

PSD of carbon microporous and mesoporous materials with pores from 3.5 to 1000 Å. Assumption: Infinit slit pore model. This model can be applied to adsorption data measured up to saturation (2130 torr)
Carbon Ar, 87K 2D – Disc, AR*=6 2D-NLDFT

23 ]

PSD*** of carbon microporous materials with pores from 3.5 to 250 Å. Assumption: 2D model of finite slit pores having a diameter-to-width aspect ratio of 6.
Carbon Ar, 87K 2D – Disc, AR*=12 2D-NLDFT

23 ]

PSD of carbon microporous materials with pores from 3.5 to 250 Å. Assumption: 2D model of finite slit pores having a diameter-to-width aspect ratio of 12.
Carbon Ar, 87K Infinite Slit NLDFT

3 ]

PSD of carbon microporous and mesoporous materials with pores from 3.5 to 1000 Å. Assumption: infinite slit pore model
Carbon N2, 77K 2D – Disc, AR*=6 2D-NLDFT

23 ]

PSD of carbon microporous materials with pores from 3.5 to 250 Å. Assumption: 2D model of finite slit pores having a diameter-to-width aspect ratio of 6.
Carbon N2, 77K 2D – Disc, AR*=12 2D-NLDFT

(123]

PSD of carbon microporous materials with pores from 3.5 to 250 Å. Assumption: 2D model of finite slit pores having a diameter-to-width aspect ratio of 12.
Carbon N2, 77K Infinite Slit NLDFT

[23]

PSD of carbon microporous and mesoporous materials with pores from 3.5 to 1000 Å. Assumption: infinite slit pore model
Carbon** N2, 77K Infinite Slit NLDFT

5, 6, 7, 8]

PSD of carbonaceous materials with pores from 3.5 to 3000 Å
Carbon** Ar, 87K Infinite Slit NLDFT

[5, 6, 7, 8 ]

PSD of carbonaceous materials with pores from 3.5 to 3000 Å
Carbon** CO2, 273K Infinite Slit NLDFT

[2, 3]

PSD of carbonaceous materials with pores from 3.5 to 10 Å
Zeolite** N2, 77K Cylinder NLDFT

[6, 8 ]

PSD of oxides and Na, Ca, K exchanged zeolites
Zeolite** N2, 77K Cylinder NLDFT

[2, 3, 9 ]

PSD of oxides and H and NH exchanged zeolites
Zeolite** Ar, 87K Cylinder NLDFT

[2, 3, 9 ]

PSD of oxides and H and NH exchanged zeolites
Pillard clay** N2, 77K Window NLDFT

10, 11, 12, 13 ]

PSD of pillared clays
All** N2, 77K Solid surface NLDFT

[6 ]

Surface energy distribution for materials containing no micropores or small mesopores.
All** Ar, 87K Solid surface NLDFT

[6 ]

Surface energy distribution for materials containing no micropores or small mesopores.

 

*   AR is the diameter-to-width aspect ratio

** Distributed with original DFT software

*** PSD = Pore Size Distribution