Measurement of sorption and diffusion in nonporous membranes by transient permeation experiments

Measuring the transient diffusion of vapor mixtures through dense membranes

“…This phenomenon can be explained either by an inadequate model of equilibrium vapor sorption, which does not accurately fit the data on sorption of alcohols in PDMS below activities of approximately 0.5 (see Fig. 4), or by inadequacy of the Long's model for this 2 Maplesoft, Waterloo Maple, Canada. particular system.…”

“…The initial and boundary conditions for the permeation experiments are of the form (x, 0) = 0, (0, ) = (a in ( )), (l, ) = (a out ( )), (2) where a in ( ) and a out ( ) are the time-dependent activities of the diffusing compound in the feed mixture and in the permeate. If the permeation flux becomes negligible compared with the feed supply and with the removal of the permeate, a in ( ) approaches the step function [14] and a out ( ) approaches the zero function.…”

“…In particular, the mass spectrometer [1][2][3] and the infrared spectrometer [4,5] have been discussed as promising devices for measuring the transient diffusion of mixtures. Several authors used mass spectrometers (MS) for time-resolved single target-compound analysis [6,2,7,8]. Hasegawa et al [9] described a pervaporation unit capable of real-time analysis of a multicomponent low-pressure permeate by direct sampling in a mass spectrometer.…”

Glycopolymer-filled microporous polypropylene membranes for pervaporation dehydration

“…On the other hand, sorption properties have often been taken as a measurement of the affinity interactions between the membrane materials and the solvent molecules [34,35]. In this work, water, isopropanol, and their mixture were selected for the sorption experiments.…”

The correlation between solvent treatment and the microstructure of PAN-b-PEG copolymer membranes

“…17 Our previous work has reported the solubility and diffusion behavior of typical gasoline components through PEG membranes by sorption experiments. 18 The detailed study of the solution of gasoline molecules on the PEG membrane has provided information that is helpful in optimizing membrane performance, but sorption experiments performed with immersion tests could not meet the accuracy of the variation of the weight change, especially for polymers with good solvent-resistance properties.…”