Atomic force microscopy, nitrogen adsorption-desorption, and measurements of intrinsic permeability are used to characterize ceramic membranes made using a newly developed alumoxane-based method conceived as an environmentally benign process. AFM, BET and permeability data indicate that the alumoxane synthesis pathway can be used to readily produce unsupported membranes with pore sizes in the range of 10-20 nm and with permeabilities comparable to those of anodized alumina membranes.