Particle size distribution and zeta potential
The size of the bran particles was determined using a laser diffraction analyzer (Malvern Instruments Ltd., Mastersizer 2000—model APA2000, Worcestershire, England) equipped with a dispersion unit (Hydro 2000S, modelAWA2001) to improve the dispersibility of the sample; ethanol was used as solvent. Zeta potential and length size distribution of the cellulose nanofibers were measured with a light scattering analyzer for nanoparticles (Malvern Instruments Ltd., Zetasizer Nano Series—model Nano ZS, Worcestershire, England). All the experiments were performed in triplicate, and the results are presented as mean values.