Interfacial properties of cellulose nanoparticles with different lengths from ginkgo seed shells

Abstract

Cellulose microparticles from ginkgo seed shells were treated by high-pressure homogenization (HPH) processing ranging from 10 to 70 MPa to produce cellulose nanoparticles with different lengths. The aim of this study was to evaluate the interfacial behavior of those resulting nanoparticles using the interfacial tension and interfacial shear rheology. The results showed that although all cellulose nanoparticles lowered the interfacial tension, the interfacial behavior of nanoparticles with different lengths are different. The cellulose particles obtained from 10 MPa treatment (H-10) showed limited adsorption due to their long size and electrostatic repulsion. The strong entangled network structure was observed from cellulose nanoparticles obtained from 30 to 50 MPa treatment (H-30 and H-50). This entangled network structure probably caused faster interfacial saturation and contributed to the formation of the interfacial film with fibril entanglements. The cellulose nanoparticles obtained from 70 MPa treatment (H-70) were relatively easier to adsorb at the oil/water interface to reduce the interfacial tension and form a discontinuous monolayer due to their short size and higher hydrophobicity. Adsorbed nanoparticles layers were visualized by atomic force microscopy at planar Langmuir films, revealing the structure of formed interfacial layers is related to particle length. Emulsions stabilized by H-10 exhibited the bad storage stability because H-10 could not effectively adsorb at the interface to form a complete interfacial film. Emulsions stabilized by H-30, 50, and 70 showed the benign storage stability due to the formation of the strong interfacial film and network structure in emulsions. This study improved understanding about interfacial properties of cellulose nanoparticles with different lengths.