Sorption-induced deformation of microporous solids studied by in-situ dilatometry

• Microporous materials such as zeolites and amorphous carbons show a characteristic signature in terms of deformation as a result of micropore filling. Here we present analysis of synthetic microporous carbons with different annealing temperatures and consequently different average micropore sizes by gas adsorption combined with in-situ dilatometry. Measurements performed with N2 (77 K), Ar (77 K), CO2 (273 K) and H2O (298 K) all reveal the same general trends with respect to sorption-induced deformation, i.e. contraction of the samples at low micropore filling followed by a phase of monotonic expansion up to complete micropore filling. However, the extent and ranges in relative pressure related to contraction and expansion, respectively, are found to clearly differ for the specific combination of micropore size and analysis gas. Our results indicate that adsorption of different gases and vapors in slit shaped micropores with pore width below 0.9 nm yield a net expansion of the sample while adsorption in micropores with pore width above 0.9 nm results in contraction and expansion of similar extent. © 2013 American Society of Civil Engineers.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

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