New fullerene derivatives, tri-cyanohydrofullerene, HC60(CN)(3), and poly{4-[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]benzyl}fullerene,C-60(TEO)(n ), have been synthesized as additives for proton conducting membranes. The new compounds have been incorporated in Nation (R) to fabricate a composite by a newly developed solution cast method. The fullerene-Nafion (R) membranes exhibited an excellent handling with no extensive phase separation. C-60(TEO)(n) has also been found to be very effective in improving the dispersion of HC60(CN)(3) in the Nafion (R) matrix. The fullerene composite membranes have demonstrated enhanced proton conductivity under low relative humidity conditions compared to a recast Nafion(D membrane. The membrane characterization was performed through optical microscopy, SEM, and water uptake measurements. (c) 2006 Elsevier B.V. All rights reserved.