Characterization of Nanocellulose Using Small-Angle Neutron, X-ray, and Dynamic Light Scattering Techniques

Abstract

Nanocellulose extracted from wood pulps using TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation and sulfuric acid hydrolysis methods was characterized by small-angle neutron scattering (SANS), small-angle X-ray scattering (SAXS), and dynamic light scattering (DLS) techniques. The dimensions of this nanocellulose (TEMPO-oxidized cellulose nanofiber (TOCN) and sulfuric acid hydrolyzed cellulose nanocrystal (SACN)) revealed by the different scattering methods were compared with those characterized by transmission electron microscopy (TEM). The SANS and SAXS data were analyzed using a parallelepiped-based form factor. The width and thickness of the nanocellulose cross section were ∼8 and ∼2 nm for TOCN and ∼20 and ∼3 nm for SACN, respectively, where the fitting results from SANS and SAXS profiles were consistent with each other. DLS was carried out under both the V mode with the polarizer and analyzer parallel to each other and the H mode having them perpendicular to each other. Using rotational and translational diffusion coefficients obtained under the H mode yielded a nanocellulose length qualitatively consistent with that observed by TEM, whereas the length derived by the translational diffusion coefficient under the V mode appeared to be overestimated.

Structural changes in sugarcane bagasse cellulose caused by enzymatic hydrolysis

“…A shoulder feature was found at around q = 1 nm −1 for cellulose both before and after treatment with cellulase. This could be explained by the presence of highly dispersed cellulose microfibrils with sharp interfaces with the solvent, as was found in previous studies [16,17]. The higher q-region of this shoulder feature (1.5-2.5 nm −1 ) was successfully fitted using the power law in the form I (q) ∝ q −D , where D = 4 for both samples, as shown in Fig.…”

Characterization of pulp derived nanocellulose hydrogels using AVAP® technology

“…Although the cellulose molecular backbone is common to all; surface morphology, size, chemical and physical properties can vary greatly depending upon the material source and extraction methods used (Mao et al, 2017). The objective of this study was to examine the physicochemical properties of NC fibrils, CNCs and a novel blend of these materials produced via the AVAP® technology.…”

Industrial Application of Nanocelluloses in Papermaking: A Review of Challenges, Technical Solutions, and Market Perspectives

“…Several authors have demonstrated the usefulness of scattering techniques to determine the dimensions of dispersed NC. Statistically averaged cross section dimensions of CNC and CNF can be determined by means of small-angle neutron scattering and small-angle X-ray scattering [133] by modeling them as rigid parallelepipeds with very high aspect ratio as the length of nanofibrils is much larger than their section. The use of dynamic light scattering (DLS) for dimensional characterization of NC presents several challenges: First, it requires dust-free sample preparation because microparticles of dust movement is much slower than that for nanocellulosic particles and they can saturate the detector resulting in a false measurement result.…”

“…The use of dynamic light scattering (DLS) for dimensional characterization of NC presents several challenges: First, it requires dust-free sample preparation because microparticles of dust movement is much slower than that for nanocellulosic particles and they can saturate the detector resulting in a false measurement result. Second, the length of NC particles usually reaches the submicron or even micron scale which makes both DLS measurement and data interpretation challenging [133]. Finally, DLS gives the hydrodynamic dimensions assuming that particles are spheres and the particle size is determined from that considering that the particle concentration is low enough to assure that diffusion takes place only by means of Brownian movement and the aggregation of particles is impaired; particle flexibility and surface charge can interfere the measurement too [134].…”