Shear-Dependent Structures of Flocculated Micro/Nanofibrillated Cellulose (MNFC) in Aqueous Suspensions

In recent years, alternatives have been sought for the reuse of lignocellulosic waste generated by agricultural and other industries because it is biodegradable and renewable. Lignocellulosic waste can be used for a wide variety of applications, depending on their composition and physical properties. In this chapter, we focus on the different treatments that are used for the extraction of natural cellulose fibers (chemical, physical, biological methods) for more sophisticated applications such as reinforcement in biocomposites. Due to the different morphologies that the cellulose can present, depending from sources, it is possible to obtain cellulose nanocrystals (CNCs), micro- nanofibrillated cellulose (MFC/NFC), and bacterial nanocellulose (BNC) with different applications in the industry. Among the different cellulose nanomaterials highlighted characteristics, we can find improved barrier properties for sound and moisture, the fact that they are environmentally friendly, increased tensile strength and decreased weight. These materials have the ability to replace metallic components, petroleum products, and nonrenewable materials. Potential applications of cellulose nanomaterials are present in the automotive, construction, aerospace industries, etc. Also, this chapter exhibits global market predictions of these new materials or products. In summary, lignocellulosic residues are a rich source of cellulose that can be extracted to obtain products with high value-added and eco-friendly characteristics.

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Correlations between rheological behavior and intrinsic properties of nanofibrillated cellulose from wood and soybean hulls with varying lignin content

BioResources ◽

10.15376/biores.16.3.4831-4845 ◽

2021 ◽

Vol 16 (3) ◽

pp. 4831-4845

Author(s):

Maria C. Iglesias ◽

Fatima Hamade ◽

Burak Aksoy ◽

Zhihua Jiang ◽

Virginia A. Davis ◽

...

Keyword(s):

Chemical Composition ◽

Charge Density ◽

Rheological Behavior ◽

Colloidal Stability ◽

Nanofibrillated Cellulose ◽

Raw Material ◽

Chemical Compositions ◽

Intrinsic Properties ◽

Soybean Hulls ◽

Aqueous Suspensions

Effects of raw material and chemical composition were considered relative to the intrinsic properties and the rheological behavior of nanofibrillated cellulose aqueous suspensions (CNFs). Atomic force microscopy, Fourier-transform infrared spectroscopy, surface chemistry analysis, thermal gravimetrical analysis, and zeta-potential were used to study the morphology, chemical composition, charge density, as well as thermal and colloidal stability of the different CNFs. Regarding the rheological properties of the samples, steady-state and oscillation studies of the CNF aqueous suspensions obtained from wood and soybean hulls were performed. An interesting correlation was found between the rheological behavior of CNF suspensions and their intrinsic properties. Soybean CNF presented lower viscosities than wood samples, which could be related to their morphology and charge density. Additionally, unbleached soybean CNF (sb-LCNF) showed yield stress compared with the other samples, which could be attributed to the presence of pectin. Furthermore, the different chemical compositions between the samples affected their thermal properties, as well as on their crystallinity.

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