Methods for dissolving carbon materials such as, for example, graphite, graphite oxide, oxidized graphene nanoribbons and reduced graphene nanoribbons in a solvent containing at least one superacid are described herein. Both isotropic and liquid crystalline solutions can be produced, depending on the concentration of the carbon material The superacid solutions can be formed into articles such as, for example, fibers and films, mixed with other materials such as, for example, polymers, or used for functionalization of the carbon material. The superacid results in exfoliation of the carbon material to produce individual particles of the carbon material. In some embodiments, graphite or graphite oxide is dissolved in a solvent containing at least one superacid to form graphene or graphene oxide, which can be subsequently isolated. In some embodiments, liquid crystalline solutions of oxidized graphene nanoribbons in water are also described.