Production of nanocellulose with different length from ginkgo seed shells and applications for oil in water Pickering emulsions.

The high-pressure homogenization (HPH) was used as a post-treatment after acid hydrolysis to alter the morphology and physical properties of ginkgo seed shells cellulose and the resulting nanocellulose were applied to stabilize O/W Pickering emulsions. The length of nanocellulose decreased from 1500 nm to 406 nm with the increasing of homogenization pressure from 10 to 70 MPa. The shorter nanocellulose exhibited higher hydrophobicity and was beneficial for reducing interfacial tension between oil and water. The suspension of longer nanocellulose exhibited a fluid gel behavior. The length of nanocellulose affected the surface coverage ratio of emulsions, which long nanocellulose leaded to a low coverage ratio and short nanocellulose caused a high coverage ratio. Emulsions containing oil phase ranging from 10 to 70% (v/v) could be prepared by only small amounts of nanocellulose treated by 50 MPa (C-50). In addition, the emulsions showed benign stability against a wide range of temperature, pH, and ionic strength environments. The results indicated C-50 not only has the similar amphipathic properties as the cellulose nanocrystals, but also has a relatively long size, showing the property of being as entangled with each other as cellulose nanofibers to form a network structure.