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The transport properties of hybrid membranes based on polyvinylchloride (PVC) was studied for the separation of Toluene Á n -Heptane mixtures by pervaporation (PV). Aromatic-alkane mixtures are difficult to fractionate by conventional processes and PV has already been shown as a promising technology in this case. PVC was chosen as starting material in this study because it gathers two key advantages: firstly, it is a technical polymer which is readily available, conversely to speciality polymers often developed for membrane application; secondly, PVC is a polar polymer endowed with a good affinity for aromatic solvents. Thus mixed matrix PVC membranes were studied to determine if it was possible to obtain interesting separation properties from this simple and cheap polymer. We report the results obtained with several types of clay used as fillers to get hybrid PVC membranes. Hence, PVC based mixed matrix membranes were prepared with Maghnite H, Maghnite H', Wyoming, Kaolin and Nanocor clay particles. It was found that the PVC transport properties could be drastically modified both by the amount and by the type of clay incorporated. According to the fillers incorporated in the polymer matrix, it was shown that the transport properties could be easily tuned either as barrier materials or as Toluene selective membranes with strongly enhanced flux compared to initial PVC membranes.

The permeation properties of PVC can be strongly modified by incorporation of fillers, leading either to the reinforcement of its barriers properties (i.e. with Wyoming or Kaolin) or to much higher mass transfer properties (i.e. with Maghnite or Nanocor). In this last case, the exact mechanism of the registered PV properties has not yet been fully elucidated, either with Maghnite or with Nanocor, but it is seems that both the specific surface and the particle size play a key role. Finally these results show that modified PVC membranes exhibit rather good performances for Toluene Á n -Heptane separation which is well known to be difficult to achieve.