The time lag in surface diffusion evaluated for the BET and BSB isotherms

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F21%3A00349654" target="_blank" >RIV/68407700:21110/21:00349654 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1063/5.0047728" target="_blank" >http://dx.doi.org/10.1063/5.0047728</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1063/5.0047728" target="_blank" >10.1063/5.0047728</a>

Jazyk výsledku

angličtina

Název v původním jazyce

The time lag in surface diffusion evaluated for the BET and BSB isotherms

Popis výsledku v původním jazyce

One of the experimental methods to determine the coefficient of surface diffusion of species migrating in a porous material uses the measurement of the time lag. It represents the time required for the species to spend their life within the material when permeating through it. Describing the mass transport by a suitable transport model, the time lag can be expressed in terms of integrals whose evaluation depends on the adsorption isotherm of the studied species in the material. For porous building materials, the BET (Brunauer–Emmett–Teller) and BSB (Brunauer–Skalny–Bodor) model isotherms are usually very good approximations to the measured isotherms at low and medium concentrations. In this paper we derive a formula for the time lag for both these model isotherms. The formula can be readily applied in the analysis of experimental data, whereas the general expression involving integrals is much less straightforward to employ, being usually evaluated numerically for fixed values of parameters. The sensitivity of the time lag formula to the surface diffusivity is illustrated for an example of a porous brick with a water adsorption isotherm known from previous experiments.

Název v anglickém jazyce

The time lag in surface diffusion evaluated for the BET and BSB isotherms

Popis výsledku anglicky

One of the experimental methods to determine the coefficient of surface diffusion of species migrating in a porous material uses the measurement of the time lag. It represents the time required for the species to spend their life within the material when permeating through it. Describing the mass transport by a suitable transport model, the time lag can be expressed in terms of integrals whose evaluation depends on the adsorption isotherm of the studied species in the material. For porous building materials, the BET (Brunauer–Emmett–Teller) and BSB (Brunauer–Skalny–Bodor) model isotherms are usually very good approximations to the measured isotherms at low and medium concentrations. In this paper we derive a formula for the time lag for both these model isotherms. The formula can be readily applied in the analysis of experimental data, whereas the general expression involving integrals is much less straightforward to employ, being usually evaluated numerically for fixed values of parameters. The sensitivity of the time lag formula to the surface diffusivity is illustrated for an example of a porous brick with a water adsorption isotherm known from previous experiments.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

20505 - Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics; filled composites)

Projekt

<a href="/cs/project/FV40007" target="_blank" >FV40007: Inovace technologie výroby lehčeného cihelného střepu pro tenkostěnné cihelné bloky</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

AIP Conference Proceedings 2343

ISBN

9780735440883

ISSN

0094-243X

e-ISSN

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Počet stran výsledku

4

Strana od-do

—

Název nakladatele

American Institute of Physics

Místo vydání

Melville, New York

Místo konání akce

Heraklion

Datum konání akce

29. 4. 2020

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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