The invention is directed, in part, to stable compositions of suspended carbon nanotubes, methods of making them, and uses thereof. The invention provides methods of producing high and low concentrations of highly dispersed carbon nanotubes suspended in a liquid. The carbon nanotube suspensions are of use in generating products with improved strength, weight, strength to weight ratio, electrical and thermal versatility, radiation shielding, capacitance, dielectric properties, selective ion flow, catalytic activity and biological applications. The invention provides for industrial processing of materials comprising carbon nanotubes such as, but not limited to, fibers, films, synthetic membranes, coatings, drug delivery systems, and molecular circuitry components.