Progress on Materials Reinforcement using Mechanically Defibrillated Cellulose Nanofibers

Abstract

Cellulose nanofibers (CNFs) are highly crystalline, fibrous materials with a high aspect ratio of long cellulose molecules linked together with strong hydrogen bonds. These long cellulose molecules are incorporated into hemicellulose and lignin, the cell walls of higher plants. The modulus of elasticity of CNF remains constant between 200 °C and +200 °C. However, the linear coefficient of thermal expansion of cellulose fibers was 0.17 ppm/K, which is comparable to that of quartz glass. Further, CNFs have a thermal conductivity in the same order of magnitude as glass. Therefore, they are promising next-generation fiber owing to the excellent mechanical and thermal properties, sustainability, and biodegradability of CNF. Most studies on using CNFs to increase strength have focused on polymer matrix composites, particularly biodegradable polymers. However, it is difficult to increase the strength of materials using CNFs due to the agglomeration of CNFs. Compared to other composite materials, the uniform dispersion of nanosized CNFs is crucial. This article reports that CNFs may behave not as reinforcing fibers but as cross-linking agents to strengthen the polymer when the amount of CNFs is very small in polymer matrix composites, and the addition of CNFs is also effective in strengthening silk yarn and Ti. The mechanical properties of the ceramic green bodies can be increased using CNFs as an auxiliary agent in ceramic slurry. Moreover, the fabrication of composite materials using CNFs is essential for expanding the CNFs applications.

Application of Metal Sputtering Treatment to Cellulose Materials Used as Co-Deposited Material for Electrolytic Nickel Composite Plating

“…CNF composited polymers have shown better mechanical performance compared to the base polymer, making them suitable for various industries 15) such as automotive 16) , packaging 17) , medical implant 18) , electronics [19][20][21] , building material 22) , and paper 23) . On the other hand, there are very few reports on composite materials with cellulose added to metal-based matrices, with only a few examples being the addition of CNF to sintered metal materials by Kurita et al 24) and Osada et al 25) Therefore, we have proposed and studied the fabrication of metal-based CNF composite films by a electrolytic composite plating method 26,27) . Further improvement of wear resistance due to the intervention of CNF is expected by compositing CNF into nickel (Ni) plated film which is widely used industrially for its superior corrosion, wear, and heat resistance.…”

An Evaluation of the Wear Resistance of Electroplated Nickel Coatings Composited with 2,2,6,6-Tetramethylpiperidine 1-oxyl-Oxidized Cellulose Nanofibers

“…However, very few studies have reported on composite materials with cellulose added to metal-based matrices. Recently, in 2022, Kurita et al reported a titanium (Ti) sintered material with the addition of cellulose nanofibers [ 18 ]. The material was strengthened by the formation of titanium carbide from carbonized cellulose nanofibers during the sintering process, and the Ti–cellulose nanofiber composite material with 3.25 mass% cellulose nanofibers achieved a tensile strength of over 700 MPa, twice that of pure titanium [ 18 ].…”

“…Recently, in 2022, Kurita et al reported a titanium (Ti) sintered material with the addition of cellulose nanofibers [ 18 ]. The material was strengthened by the formation of titanium carbide from carbonized cellulose nanofibers during the sintering process, and the Ti–cellulose nanofiber composite material with 3.25 mass% cellulose nanofibers achieved a tensile strength of over 700 MPa, twice that of pure titanium [ 18 ]. In 2023, Osada et al applied cellulose nanofibers as an additive to binder in metal powder injection molding of stainless steel, and they reported the effects of suppressing deformation during sintering and reducing the oxygen content of sintered material [ 19 ].…”