Evaluation of Fiber Length and Dispersibility of Mono-Dispersed Cellulose Nanofibers

Introduction

Cellulose is a polysaccharide consisting mainly of plant cell walls. Nanocellulose is produced by defibrating cellulose to the nanometer size. Nanocellulose with a diameter of 4 to 100 nm, length of approximately several μm, and high aspect ratio (100 min.) is called cellulose nanofiber (CNF), and is a focus of attention as an advanced new biomass material. In addition to light weight and high strength, CNF also offers outstanding functions such as a high gas barrier property, adsorption, and transparency. Moreover, because CNF is a plant fiber-derived material, the environmental impacts associated with production and disposal are small. Application to automotive, electronic, packaging and other materials is expected in the future. The lack of an established method for evaluating the basic physical properties of CNF is one current issue. As basic measurements, establishment of a method for measuring the fiber length and diameter of CNF is demanded, as they are thought to influence the mechanical strength of CNF composites. Application News No. S30 introduced a method for measuring the fiber length/diameter by using a scanning probe microscope (SPM). This research examined the use of a particle size analyzer and UVvisible spectrophotometer in addition to SPM. The particle size analyzer is used to evaluate a large quantity of fibers rapidly, for example, in quality control applications, and the UVvisible spectrophotometer is used to evaluate the correlation between fiber length and dispersibility with the aim of enhancing the dispersibility of CNF in the matrix. The following introduces evaluation of fiber length by using the Shimadzu single nano particle size analyzer IG-1000 Plus and scanning probe microscope SPM-9700HT^™, and evaluation of dispersibility by using the UV-visible spectrophotometer UV-2600.

January 22, 2021 GMT