A composite membrane (TS-1/PDMS) was used as a catalytic interphase contactor in the two-phase reaction of n-hexane oxyfunctionalization by hydrogen peroxide. An experimental study allowed to establish the effects of the main membrane parameters (thickness, loading, chemical modifications...) on the performances of the membrane reactor. A simple mathematical model of the catalytic phase contactor was derived and shown to represent quantitatively the observed experimental trends. (C) 2000 Elsevier Science B.V. All rights reserved.