This is a combined effort of researchers from Australia India and Japan. The paper is available at this link. They looked at the way graphene oxide nanoplates (GO) interacted with water vapour. They observed that GO imparts a very high water uptake capacity up to 0.58 gram of water per gram of GO (g g-1) This is significantly higher than silica gel a conventional desiccant material.
More interestingly, the adsorption and desorption kinetics of GO is five times higher than silica gel. The observed extraordinary adsorption/desorption rate can be attributed to the high capillary pressure in GO laminates as well as micrometre-sized tunnel like wrinkles located at the surface.
So well over a third of the weight of graphene oxide powder could be moisture and the amount will depend on the humidity of the storage areas between the manufacturing site and the point of use. The moisture content will be an important quality control parameter for buying GO. It will also be an important technical service factor to consider when customers use GO powders as an additive because variations in the moisture content could affect the physical properties and addition amount. This could also introduce variability into the customer’s final product.