The first portion was neutralized by aqueous Na2CO3 solution, centrifuged at 9000 rpm for 20 min to separate CNFs from the suspension. The aqueous phase was decanted and CNFs was re-dispersed in water, re-centrifuged twice under the same parameters. CNFs produced from this portion were described as (H2SO4 neutralized CNFs). The second part was centrifuged to remove the excess amount of acid, then dialyzed against deionized water for four days using regenerated cellulose tubing (MWCO 50 kD) until the pH of solution became neutral. The produced CNFs from this portion was described as (H2SO4 dialyzed CNFs).