Low-energy method for preparing underivatized nanocellulose

Low-energy method for preparing a material nanocellulose underivatized comprising (a) treating a cellulosic material with a swelling agent for swelling cellulosic material, (b) subjecting said inflated to an effective process of mechanical shredding cellulosic material, such as high shear forces, high pressure homogenization, microfluidization, forces high friction, and combinations thereof, and (c) isolating material nanocellulose, wherein the blowing agent is a blowing agent that breaks only the intercrystalline regions and wherein the cellulosic material is characterized by a swelling index between 1.5 and 3 in said swelling agent, and also that the swelling agent is an aqueous solution of morpholine, piperidine or mixtures thereof comprising the 70 to 99% (by volume) of morpholine, piperidine or mixtures thereof, respectively.