Corrected thermodynamic description of adsorption via formalism of the theory of volume filling of micropores

Terzyk, Artur P.; Gauden, Piotr A.; Rychlicki, Gerhard

doi:10.1016/j.jcis.2005.12.007

Cited by 7 publications

(6 citation statements)

References 45 publications

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“…Nitrogen adsorption-desorption isotherms measured for all four carbon samples are compared in figure 2. For D55/2 we observe type I of the adsorption-desorption isotherm (this carbon is strictly microporous), according to the BET classification, whereas for the PICA HP it is of the type IV (this is micro-mesoporous carbon [19,20]). For carbon nanotubes type IV is also observed, typical for mesoporous materials.…”

Section: Resultsmentioning

confidence: 90%

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Carbon materials as new nanovehicles in hot-melt drug deposition

Bielicka¹,

Wiśniewski²,

Terzyk³

et al. 2013

J. Phys.: Condens. Matter

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The application of commercially available carbon materials (nanotubes and porous carbons) for the preparation of drug delivery systems is studied. We used two types of carbon nanotubes (CNT) and two activated carbons as potential materials in so-called hot-melt drug deposition (HMDD). The materials were first studied using Raman spectroscopy. Paracetamol was chosen as a model drug. The performed thermal analysis, kinetics, and adsorption-desorption studies revealed that nanoaggregates are formed between carbon nanotubes. In contrast, in pores of activated carbon we do not observe this process and the drug adsorption phenomenon mechanism is simply the filling of small pores. The formation of nanoaggregates was confirmed by the results of GCMC (grand canonical Monte Carlo) simulations and the study of the surface area on nitrogen adsorption-desorption isotherms. The application of carbon nanotubes in HMDD offers the possibility of controlling the rate of drug delivery. Performed MTT tests of nanotubes and drug-loaded nanotubes show that the observed decrease in cell viability number is caused by the influence of the cytostatic properties of nanotubes-they inhibit the proliferation of cells. The carbon nanotubes studied in this paper are essentially nontoxic.

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Section: Resultsmentioning

confidence: 90%

“…Two commercially available, high-purity, closed carbon nanotubes provided by two producers [14,18] and two commercially available carbon materials also from two sources [19,20] were investigated. The tubes labelled as A-0 were single-walled carbon nanotubes (from Nanostructured and Amorphous Materials, Nanoamor, Houston, TX, USA).…”

Section: Methodsmentioning

confidence: 99%

Carbon materials as new nanovehicles in hot-melt drug deposition

Bielicka¹,

Wiśniewski²,

Terzyk³

et al. 2013

J. Phys.: Condens. Matter

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“…1, shows that the values from DA theory are lower than the calorimetric heats. Various authors have proposed modifications to (1) (Terzyk 2006). In the present work we tested to add to the right side of (1), which already includes a term for the heat of condensation (L), the heat of fusion.…”

Section: Resultsmentioning

confidence: 99%

“…The values of E and n in this work were obtained by fitting the DA equation to the experimental data (adsorption isotherms). The characteristic energy (E) being a parameter related to the adsorption energy, has been compared with the heats of adsorption measured by calorimetry (Stoeckli et al 1994;Gauden et al 2004;Terzyk et al 2006). As shown elsewhere (Dubinin 1979;Stoeckli et al 1994;Terzyk et al 2006) the isosteric heat of adsorption (q st ) can be related to parameters from the DA equation by:…”

Section: Introductionmentioning

confidence: 99%

Heats of adsorption from the Dubinin-Astakhov model applied to the characterization of pillared interlayered clays (PILCs)

Pires

Pinto

Guil³

2010

Adsorption

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Heats of adsorption of organic molecules are a useful tool for the characterization of porosity and surface chemistry of microporous materials. This work describes the possibility of using heats of adsorption of organic molecules, estimated from a methodology derived from the Dubinin-Astakhov equation, for the characterization of Pillared Interlayered Clays. The estimated heats were compared with data determined directly by adsorption microcalorimetry. It is shown that the chemical nature of the organic probe molecule strongly conditions the obtained results. The best agreement between calculated and experimental values, amongst the probe molecules studied, was found for toluene.

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“…To explore the specific behavior of the molecules in micropores, the adsorption characteristics of N 2 , Ar, and CO 2 in different microporous materials were analyzed, and the DA equation was used to characterize and calculate the adsorption potential distribution, pore size distribution, and micropore filling rate of the microporous materials [29][30][31]. The TVFM theory was applied to modify the description of adsorption thermodynamics [32], the main occurrence of methane in coals was explored [33,34], and the TVFM theory was extended to the study of ultra-microporous adsorption. The characteristic capacity of ultra-microporous adsorption could be enhanced, indicating that this effect is due to the large potential field overlap relative to the pore wall and the reduction in the surface adsorption film in terms of the volume of the filled micropores [35].…”

Section: Introductionmentioning

confidence: 99%

Critical pore size for micropore filling in coal samples with different rank coals

et al. 2022

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The objectives of this study were to explore the occurrence and migration of coalbed methane in coals of different ranks and reveal the microscopic reservoir space and the mechanism of coalbed methane. To meet these objectives, this study selected six coal samples of different coal ranks for low-pressure N2 adsorption experiments, explored the critical pore filling characteristics of packed N2 molecules in the coals, and analyzed the low-pressure N2 adsorption/desorption experimental isotherms using the DFT method and DA equation based on the micropore filling theory. Finally, the critical filling pressure and pore size range for micropore filling were determined, and the analysis results were verified by combining the Langmuir, DA, and BET equations. The results showed that, from low to high coal rank, the N2 adsorption/desorption isotherms of the coal samples transition from type Ⅱ to type Ⅰ. The proportion of N2 molecules in low-rank coals in the form of micropore filling and monolayer adsorption was higher than that in high-rank coals. The critical pressure and critical pore size for micropore filling exhibited U-shaped correlations with the coal rank. Low-rank coals (lignite and long flame coal) were gradually filled in the relative pressure range P/P0 ≈ 1E-4–0.03, and medium- and high-rank coals (gas coal, 1/3 coking coal, lean coal, and anthracite) were filled in the relative pressure range P/P0 ≈ 1E-4–0.01; the corresponding critical pore size ranges were 1.7–2.19 and 1.61–2.00 nm, respectively.

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Corrected thermodynamic description of adsorption via formalism of the theory of volume filling of micropores

Cited by 7 publications

References 45 publications

Carbon materials as new nanovehicles in hot-melt drug deposition

Carbon materials as new nanovehicles in hot-melt drug deposition

Heats of adsorption from the Dubinin-Astakhov model applied to the characterization of pillared interlayered clays (PILCs)

Critical pore size for micropore filling in coal samples with different rank coals

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