A new protocol for efficient and high yield preparation of cellulose nanofibrils

Nanocellulose has attracted considerable attention in virtue of the unique mechanical and optical properties. There were less cost-efficient methods for its mass production. In this paper, a facile high yield procedure for cellulose nanofibrils consisting of sulfuric acid treatment followed by alkali neutralization and homogenization was developed. The product was termed “acid-assisted cellulose nanofibrils” (AACNF). AACNF yield was 91.6% from dissolving pulp when 55 wt% sulfuric acid was applied at 45 °C for 40 min. The diameter was 10–20 nm, while the length varied from 40 to 800 nm. AACNF aqueous suspension showed good transparency at 600 nm having rheological properties similar to cellulose nanocrystals. The crystallinity of AACNF was 81.3% and displayed thermal properties that in comparison to traditional nanocellulose were very attractive because of neutralization. This study provided a facile high yield procedure for the production of nanocellulose with similar characteristics to traditional nanocellulose, which was significant to commercialization of nanocellulose.