Simulating the effect of the quadrupole moment on the adsorption of nitrogen in siliceous zeolites

Specific Surface Area of Nanopowders from Argon Adsorption at 77 and 87 K: Zeta Adsorption Isotherm Approach

“…Had the comparison been restricted to a BET range of 0 ≤ x V ≤ 0.35, it would have resulted in a different and an opposite interpretation. A good description of the amount adsorbed for these vapors on nonporous substrates is essential for understanding the interaction potentials and for better characterization of porous substrates, , like ordered mesoporous materials ,,− (OMM). Such a thermodynamic isotherm, which is valid in the entire equilibrium range, is also needed to compare the results of the adsorption analysis using molecular dynamics, − performing biological studies, and analyzing the microporosity of materials like activated carbon and hard carbon .…”

“…The argon atom and the nitrogen molecule are both nonpolar and polarizable, , but argon, unlike nitrogen, does not have quadrupole moments. − Both argon and nitrogen were widely used in comparative adsorption analysis to understand the role of surface functional groups on adsorption, but an unexpected difficulty arose when the specific surface areas, A s , of several nanopowders were indicated by the Brunauer–Emmett–Teller (BET) approach to have significantly different values depending on whether argon or nitrogen vapor was used to make the measurements. , The reasons for this disagreement in the values of A s were suggested by Sing and colleagues to result from the BET interpretation of the adsorption measurements. − Mikhail and Brunauer suggested a different cause: The difference resulted from the lateral interactions between the respective adsorbed Ar atoms or N 2 molecules …”

Adsorption of Light Gases in Covalent Organic Frameworks: Comparison of Classical Density Functional Theory and Grand Canonical Monte Carlo Simulations

“…Of course, the influence of the partial atomic charges on the adsorption behavior strongly depends on the magnitude of the charges of the adsorbent-framework, as reported for siliceous zeolites. 77 For here considered COF 2,3-DhaTph nitrogen adsorption isotherms with and without framework partial charges show only minor differences (see Figure S7 in the Supporting Information). Figure 4 shows adsorption isotherms of nitrogen, methane and n-butane in COF TpPa-1 at 298 K up to a pressure of 50 bar.…”

Influence of Layer Slipping on Adsorption of Light Gases in Covalent Organic Frameworks: A Combined Experimental and Computational Study

“…For carbon dioxide the influence at 288 K is larger, so that neglecting solid charges leads to an error up to 10 %. It has been shown by Hackett and Hammond 37 for sileceous zeolites that the influence of partial atomic charges on the adsorbed loading is strongly dependent on the framework geometry and the magnitude of adsorbate-framework charges. Comparison of several charge-assignment schemes for CO 2 -adsorption in MOFs also showed a significant effect in many cases.…”

“…For a detailed overview we refer to the literature. [36][37][38] The fact that most zeolites furnish unambiguous crystal structure information and are composed of a limited variety of elements (namely oxygen, aluminium, silicon and counterions) allowed to develop transferable force fields for adsorption and diffusion. [39][40][41][42][43] Fitting force field parameters to experimental isotherms in COFs or MOFs is precarious because of the various uncertainties and the fact that error cancellation might lead to non-transferable sets of parameters.…”