NOVELTY - The method comprises contacting a network of nanoscale fibers with an acid or an oxidant effective to oxidize a portion of the nanoscale fibers, contacting the network of nanoscale fibers with a conjugated polymer to graft the conjugated polymer to a portion of the oxidized nanoscale fibers, and cross-linking a portion of the conjugated polymer grafted to the portion of the nanoscale fibers by irradiating the network of nanoscale fibers with an effective amount of UV radiation or by contacting the network of nanoscale fibers with a chemical agent comprising reactive functional groups.    USE - The method is useful for functionalizing a network of nanoscale fibers such as aligned multi-walled carbon nanotubes and/or single-walled carbon nanotube, which is useful: for an article of manufacture (claimed); and to fabricate organic electronic devices, hybrid solar cells, super capacitors, transparent electrodes, chemical sensors, field emission displays, artificial muscles, high-surface-area electrodes and high-performance nanotube-reinforced composites.    ADVANTAGE - The method is capable of efficiently functionalizing the network of nanoscale fibers thus increasing the mechanical properties, electronic conductivity, doping stability and intrinsic conductivity of the nanoscale fibers in buckypapers.    DETAILED DESCRIPTION - The method comprises contacting a network of nanoscale fibers with an acid or an oxidant effective to oxidize a portion of the nanoscale fibers, contacting the network of nanoscale fibers with a conjugated polymer to graft the conjugated polymer to a portion of the oxidized nanoscale fibers, and cross-linking a portion of the conjugated polymer grafted to the portion of the nanoscale fibers by irradiating the network of nanoscale fibers with an effective amount of UV radiation or by contacting the network of nanoscale fibers with a chemical agent comprising reactive functional groups. The network of nanoscale fibers comprises a nanoscale fiber film. An INDEPENDENT CLAIM is included for an article of manufacture.    DESCRIPTION OF DRAWING(S) - The diagram shows a scanning electron microscopic view of a surface of a pristine multi-walled carbon nanotube buckypaper.