Microcrystalline cellulose (MCC) and polyamide 66 (PA66) have been separately dissolved in solutions containing trifluoroacetic acid (TFA) as a common solvent, mixed after their dissolution and cast. After solvent evaporation, self-organized membranes have been formed with three dimensional (3D) porous, interconnected morphology, the porosity of which depends on the relative ratio of cellulose and PA66, and is lost when the initial MCC content exceeds 50% by weight. Thermal and chemical analysis and Xray diffraction results indicate that the addition of cellulose induces the amorphisation of PA66, while possible chemical interaction exists between the amorphous parts of PA66 and the cellulose. The various membranes produced with different 3D porosities have been characterized in terms of dielectric constant and salt permeability and their relation to cellulose-PA66 ratio has been determined. (C) 2017 Elsevier Ltd. All rights reserved.