Daikin Industries, a heating, ventilating and air conditioning, or HVAC company, completed the acquisition of OCSiAl, a developer of graphene nanotubes designed to improve the properties of a multitude of materials. Financial terms were not disclosed. Graphene nanotubes, or as they are also called, single wall carbon nanotubes, are one-atom-thick graphene sheets rolled into tubes. This unique material, which enables the creation of products with new sets of properties, was historically observed and described for the first time by Japanese scientists.