Adsorption of vapors on model nonporous adsorbents with a physically modified surface

Berezkina, Yu. F.; Dubinin, M. M.; Sarakhov, A. I.

doi:10.1007/bf00912530

Cited by 7 publications

(5 citation statements)

References 2 publications

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“…The constant C of the BET equation, which is related to the characteristic adsorption energy in the first monolayer, was determined to be C C60 (N 2 ) = 60 and C C60/C70 (N 2 ) = 85 in the case of nitrogen and C C60 (Ar) = 30 and C C60/C70 (Ar) = 70 in the case of argon. This characterizes both bf samples as weaker than gcb ( C gcb (N 2 ) = 150, C gcb (Ar) = 320, estimated from experimental data 13 ). The C 60 and C 60 /C 70 monolayer capacities n m determined from the above fits were 0.010 and 0.117 mmol/g in the case of nitrogen and 0.0116 and 0.124 mmol/g in the case of argon.…”

Section: Resultsmentioning

confidence: 92%

Nitrogen and Argon Adsorption and SEM Characterization of C₆₀ and C₆₀/C₇₀ Fullerenes: Comparison with Graphite

et al. 1999

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The surface and pore structure properties of the C60 and C60/C70 fullerene powders were studied by means of scanning electron microscopy, helium pycnometry, and 77.4 K nitrogen and argon adsorption. The pore structure of fullerene powders is macroporous and consists mainly of the voids between the fullerene aggregates. In the major part of the adsorption monolayer, both nitrogen and argon interactions with fullerenes are weaker than with graphite, possibly because of the reduction of the gas molecule−mirror image effect in the case of fullerenes. In Henry's law limit, however, nitrogen and argon adsorption on fullerenes is quantitatively similar to that on graphite because of the adsorption potential enhancement in the spaces between the surface fullerene molecules. In the multilayer regime, nitrogen adsorption on both fullerenes becomes similar to that on graphite. Both fullerenes behave similarly with respect to the adsorption of the studied gases.

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Section: Resultsmentioning

confidence: 92%

Nitrogen and Argon Adsorption and SEM Characterization of C₆₀ and C₆₀/C₇₀ Fullerenes: Comparison with Graphite

et al. 1999

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“…Many other experimental adsorption studies of simple gas adsorption on GTCB have been reported, amongst which may be mentioned those of Isirikyan and Kiselev (1962);Sarakhov et al (1961Sarakhov et al ( , 1963; Berezkina et al (1969); Kruk et al (1999);and Gardner et al (2000) who have also reproduced experimental results by simulation and density functional calculations.…”

Section: Argon and Nitrogen On Graphitementioning

confidence: 96%

“…This demonstrates that argon and nitrogen adsorb predominantly on the basal plane, and that water adsorbs predominantly on the functional groups and/or strong sites such as defects grafted at the unsaturated locations at the edges of the graphene layers. Adsorption of argon on a carbon black graphitized at 3000 C pre-loaded with water whose amount is equivalent to 0% and 60% of the monolayer coverage of water (data taken from Berezkina et al, 1969) To substantiate this argument, we show in Figure 6 the Henry constant as a function of temperature for various adsobates on the basal plane (Figures 6a, b) and on a single carboxylic functional group (Figure 6c). At 87K for example, the theoretical Henry constant for argon on the basal plane is 1.2×10 4 nm (eq.…”

Section: Argon and Nitrogen On Graphitementioning

confidence: 99%

The interplay between molecular layering and clustering in adsorption of gases on graphitized thermal carbon black – Spill-over phenomenon and the important role of strong sites

Tan

Zeng

et al. 2015

Journal of Colloid and Interface Science

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We analyse in detail our experimental data, our simulation results and data from the literature, for the adsorption of argon, nitrogen, carbon dioxide, methanol, ammonia and water on graphitized carbon black (GTCB), and show that there are two mechanisms of adsorption at play, and that their interplay governs how different gases adsorb on the surface by either: (1) molecular layering on the basal plane or (2) clustering around very strong sites on the adsorbate whose affinity is much greater than that of the basal plane or the functional groups. Depending on the concentration of the very strong sites or the functional groups, the temperature and the relative strength of the three interactions, (a) fluid-strong sites (fine crevices and functional group) (F-SS), (b) fluid-basal plane (FB) and (c) fluid-fluid (FF), the uptake of adsorbate tends to be dominated by one mechanism. However, there are conditions (temperature and adsorbate) where two mechanisms can both govern the uptake. For simple gases, like argon, nitrogen and carbon dioxide, adsorption proceeds by molecular layering on the basal plane of graphene, but for water which represents an extreme case of a polar molecule, clustering around the strong sites or the functional groups at the edges of the graphene layers is the major mechanism of adsorption and there is little or no adsorption on the basal planes because the F-SS and FF interactions are far stronger than the FB interaction. For adsorptives with lower polarity, exemplified by methanol or ammonia, the adsorption mechanism switches from clustering to layering in the order: ammonia, methanol; and we suggest that the bridging between these two mechanisms is a molecular spill-over phenomenon, which has not been previously proposed in the literature in the context of physical adsorption.

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“…The differences in intrinsic porosities are reflected in distinct sorption characteristics of the unfilled and corresponding reinforced samples. It was reported that water absorbed in carbon filled materials follow the Dubinin-Serpinsky (D-S) mechanism [76].…”

Section: Adsorption Isothermsmentioning

confidence: 99%

MWCNTs Composites-Based on New Chemically Modified Polysulfone Matrix for Biomedical Applications

Nica¹,

Zaltariov²,

Pamfil³

et al. 2022

Nanomaterials

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Polyvinyl alcohol (PVA) is a non-toxic biosynthetic polymer. Due to the hydrophilic properties of the PVA, its utilization is an easy tool to modify the properties of materials inducing increased hydrophilicity, which can be noticed in the surface properties of the materials, such as wettability. Based on this motivation, we proposed to obtain high-performance composite materials by a facile synthetic method that involves the cross-linking process of polyvinyl alcohol (PVA) with and aldehyde-functionalized polysulfone(mPSF) precursor, prior to incorporation of modified MWCNTs with hydrophilic groups, thus ensuring a high compatibility between the polymeric and the filler components. Materials prepared in this way have been compared with those based on polyvinyl alcohol and same fillers (mMWCNTs) in order to establish the influence of the polymeric matrix on the composites properties. The amount of mMWCNTs varied in both polymeric matrices between 0.5 and 5 wt%. Fourier transformed infrared with attenuated total reflectance spectroscopy (FTIR-ATR) was employed to confirm the changes noted in the PVA, mPSF and their composites. Hemolysis degree was investigated in correlation with the material structural features. Homogenous distribution of mMWCNTs in all the composite materials has been confirmed by scanning electron microscopy. The hydrophilicity of both composite systems, estimated by the contact angle method, was influenced by the presence of the filler amount mMWCNTs in both matrices (PVA and mPSF). Our work demonstrates that mPSF/mMWCNTs and PVA/mMWCNTs composite could be used as water purification or blood-filtration materials.

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Adsorption of vapors on model nonporous adsorbents with a physically modified surface

Cited by 7 publications

References 2 publications

Nitrogen and Argon Adsorption and SEM Characterization of C₆₀ and C₆₀/C₇₀ Fullerenes: Comparison with Graphite

Nitrogen and Argon Adsorption and SEM Characterization of C₆₀ and C₆₀/C₇₀ Fullerenes: Comparison with Graphite

The interplay between molecular layering and clustering in adsorption of gases on graphitized thermal carbon black – Spill-over phenomenon and the important role of strong sites

MWCNTs Composites-Based on New Chemically Modified Polysulfone Matrix for Biomedical Applications

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Adsorption of vapors on model nonporous adsorbents with a physically modified surface

Cited by 7 publications

References 2 publications

Nitrogen and Argon Adsorption and SEM Characterization of C60 and C60/C70 Fullerenes: Comparison with Graphite

Nitrogen and Argon Adsorption and SEM Characterization of C60 and C60/C70 Fullerenes: Comparison with Graphite

The interplay between molecular layering and clustering in adsorption of gases on graphitized thermal carbon black – Spill-over phenomenon and the important role of strong sites

MWCNTs Composites-Based on New Chemically Modified Polysulfone Matrix for Biomedical Applications

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Product

Resources

About

Nitrogen and Argon Adsorption and SEM Characterization of C₆₀ and C₆₀/C₇₀ Fullerenes: Comparison with Graphite

Nitrogen and Argon Adsorption and SEM Characterization of C₆₀ and C₆₀/C₇₀ Fullerenes: Comparison with Graphite