Cellulose nanofibrils improve the properties of all-cellulose composites by the nano-reinforcement mechanism and nanofibril-induced crystallization. Issue 42 (14th October 2015)

• Record Type: Journal Article
• Authors: Yang, Quanling; Saito, Tsuguyuki; Berglund, Lars A.; Isogai, Akira
• Is Part Of: Nanoscale. Volume 7:Issue 42(2015)
• Page Start: 17957
• Page End: 17963
• Publication Date: 2015-10-14
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c5nr05511c
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Transparent all-cellulose composites prepared from cellulose nanofibrils and regenerated cellulose exhibit high mechanical strength, stiffness, thermal stability, and oxygen barrier properties with only 1% cellulose nanofibril content, resulting from the nano-reinforcement mechanism and nanofibril-induced crystallization of cellulose molecules in the matrix. Abstract : All-cellulose nanocomposite films containing crystalline TEMPO-oxidized cellulose nanofibrils (TOCNs) of 0–1 wt% were fabricated by mixing aqueous TOCN dispersions with alkali/urea/cellulose (AUC) solutions at room temperature. The mixtures were cast on glass plates, soaked in an acid solution, and the regenerated gel-like films were washed with water and then dried. The TOCN did not form agglomerates in the composites, and had the structure of TOCN–COOH, forming hydrogen bonds with the hydroxyl groups of the regenerated cellulose molecules. X-ray diffraction analysis revealed that the matrix cellulose molecules increased the cellulose II crystal size upon incorporation of TOCN. As a result, the TOCN/AUC composite films had high Young's modulus, tensile strength, thermal stability and oxygen-barrier properties. The TOCN/AUC composite films are promising all-cellulose nanocomposites for versatile applications as new bio-based materials.