AbstractThe permeation characteristics of the isomers of such aromatics as dichlorobenzenes, nitrochlorobenzenes, xylenes, etc., through a Methocel HG membrane containing various amounts of Schardinger α‐cyclodextrin and β‐cyclodextrin additives were measured in liquid/liquid dialysis and pervaporation experiments. The results showed that the cyclodextrins are able to selectively mediate molecular transport through the Methocel HG membranes. In general, increased membrane selectivity and a decrease in permeation rates were observed. Permeation rates for some aromatic compounds were decreased several hundred times with only 25 amounts of additive cyclodextrins in the Methocel HG membranes. Concentration electrical potential and bi‐ionic electrical potential in membranes containing the Schardinger cyclodextrin have been measured and also show that the cyclodextrins are able to induce ion transport selectively through nonionic membranes. Dynamic mechanical properties of Methocel HG membranes containing cyclodextrins suggest these additives to be antiplasticizing agents. A mechanism for the modification of the intrinsic membrane permeation properties by cyclodextrin additive involving antiplasticizing action by the additives plus induced tortuous diffusion, where the latter is a result of specific interactions between the cyclodextrin additive and the permeating molecules, is p
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