Method for providing a nanocellulose involving modifying cellulose fibers

A method for providing a microfibrillated cellulose (MFC) gel involving modifying cellulose fibers wherein the method comprises the following steps:

• i) treating cellulose fibers for at least 5 minutes with an aqueous electrolyte-containing solution of an amphoteric or anionic carboxymethyl cellulose or a derivative thereof, whereby the temperature during the treatment is 50° C. to 120° C., and at least one of the following conditions apply:
• A) the pH of the aqueous solution during the treatment lies in the interval of approximately 1.5-4.5;
• or
• B) the pH of the aqueous solution during the treatment is higher than approximately 11;
• or
• C) the concentration of the electrolyte in the aqueous solution lies in the interval of approximately 0.0001-0.5 M if the electrolyte has monovalent cations, or in the range of approximately 0.0001-0.1 M if the electrolyte has divalent cations,
• ii) adjusting the pH of said cellulose fibers treated in step i) if the pH is not in a range from about 5 to about 13 after step i) by using a basic or an acidic liquid into a pH range of from about 5 to about 13, wherein the cellulose fibers have attached 5 to 250 milligrams the amphoteric or anionic carboxymethyl cellulose or derivative thereof per gram dry cellulose fibers, and
• iii) treating said cellulose fibers having a pH in a range from about 5 to about 13 in a mechanical comminution device, thus providing said MFC gel.