In this paper, a new membrane separation process is presented. This process is based on a multiple chamber cell that allows the separation of oil from water by placing two membranes of different hydrophobicity in contact with the emulsion. Further chemical modifications of the membranes have been performed in order to vary their hydrophobicity in the perspective of optimizing the fractionation process via specific interactions between membrane and emulsion components. For this purpose, methylcellulose was modified with 1,2-epoxydodecane and incorporated in the membrane elaboration process. The modification of membrane surface chemical structure was demonstrated by ATR-FTIR and XPS experiments. Preliminary filtration tests are presented as well as future perspectives to optimize the membrane modification procedure. (C) 2007 Elsevier B.V. All rights reserved.