The invention discloses a method for preparing
nanocellulose at low
energy consumption. The method comprises the steps of soaking natural
cellulose into a
sodium hydroxide solution, and soaking at the temperature of 5-40 DEG C for 1-30 minutes to obtain a
mixed solution; weighing
sodium hydroxide and
ethanol, and mixing
sodium hydroxide and
ethanol, then, adding the mixture into the
mixed solution, heating the reactant to 50-78 DEG C while slowly stirring, then, adding
sodium chloroacetate, reacting for 2.5-4 hours, then, filtering, and washing with
distilled water until the solution is neutral to prepare treated
cellulose; then, mixing the solution and water to prepare a
cellulose mixed solution with the
mass percentage of 0.5-1.4%; next, shearing under the mechanical action; and finally, filtering or carrying out
centrifugal separation to prepare the
nanocellulose. By using the method disclosed by the invention, the preparation time of the
nanocellulose can be shortened to 3-4 hours, the yield is high, the consumption of a reaction
reagent is low, the consumption of
sodium chloroacetate is low, and the caused environment
pollution is low; and the method is low in
energy consumption, stable in process, good in
repeatability, mild in condition, simple and convenient to operate and suitable for large-scale popularization.