The effect of different drying methods on cellulosic nanofibers and resulting composites

In this study, the effect of different drying methods on cellulosic nanofibers and resulting composites investigated. Four methods were examined to dry nanofibrillated cellulose suspensions: air drying, oven drying, spray-drying and freeze drying. The particle size and morphology of the CNFs were determined via dynamic light scattering, scanning electron microscopy, and morphological analysis. Freeze drying formed ribbon-like structures of the CNFs with nano-scale thicknesses. Width and length were observed in tens to hundreds of microns. Spray-drying formed particles with a size distribution ranging from nanometer to several microns. Spray-drying is proposed as a technically suitable manufacturing process to dry CNF suspensions not only with dimension in nano range but also improving mechanical properties of poly (lactic acid) based composites.