All-cellulose composite and nanocomposite made from partially dissolved micro- and nanofibers of canola straw

Abstract

All-cellulose composite (ACC) and nanocomposite (ACNC) were, respectively, made from microfiber and grinding-based nanofiber of canola straw by using a partial dissolution method with the solvent N,N-dimethylacetamide/lithium chloride (DMAc/LiCl). The dissolution times were 5, 10, 20, 30, 60 and 120 mins. The resultant composites were compared with neat micro-and nanofiber sheets. The average diameter of microfiber was 26 lm, which was downsized to 32 nm after grinding. The grinding process is a simple, cheap and fast downsizing method that could reduce fiber diameter by almost three orders of magnitude. The tensile strength of the nanofiber sheet was 11 times higher than that of the microfiber sheet. As dissolution time increased, the amount of non-crystalline matrix in the ACC and ACNC increased, and the apparent crystallinity decreased. The ACC had a tensile strength of 59 MPa when the dissolution time was 120 min, whereas the ACNC approached a maximum tensile strength of 164 MPa after a short dissolution time (10 min). Fiber pull-out was observed in the tensile-broken surfaces of the micro-and nanofiber sheets, and fibers tended to break when the dissolution time was long.

Dewatering of MNFC containing microfibrils and microparticles from soybean hulls: mechanical and transport properties of hybrid films

“…The microfluidization process have been reported to diminish or reduce the defect points of cellulose fibers including inhomogeneous structures of fiber wall, lumen, pits, etc. (Sehaqui et al 2011;Yousefi et al 2011). Furthermore, as fiber diameter decreases to nano-or micro-scales, the specific surface area, the number of hydrogen bonds and the fiber entanglement increase.…”

Effects of Ozone and Nanocellulose Treatments on the Strength and Optical Properties of Paper Made from Chemical Mechanical Pulp

“…The specific area of cellulose pulps increases as the particle size shrinks at the nanometer scale. This means that more hydroxyl groups become available at the nanofiber level and are able to create hydrogen bonds with adjacent fiber surfaces, finally creating a network of nano-and regular pulps (Yousefi et al 2011); this increases various paper strengths. Using nanocellulose at a 10% level, the tensile strength was increased by 14.1%, and the tear strength decreased by 15.7%.…”

“…As can be seen in the XRD figure, the peak of pure cellulose became relatively wider. The widening of peaks is rooted in the reduction of the crystallinity (Yousefi et al 2011). …”

Preparation of Cellulose Nanofibers Reinforced Polyether-b-Amide Nanocomposite

“…In particular, the difference in entanglement can be attributed to the difference between the aspect ratios of cellulose nanowhiskers and of cellulose nanofibers produced by grinding. Grinding is simpler, cheaper, and faster than acid hydrolysis, bacterial synthesis or electrospinning, and it is a one-step, high-yield process (Yousefi et al 2011).…”