Multifunctional Bionanocomposite Foams with a Chitosan Matrix Reinforced by Nanofibrillated Cellulose

Abstract

Multifunctional bionanocomposite foams with 3D interconnected networks showing advantageous mechanical properties, thermal insulation, underwater oleophobicity, and biocompatibility, were made from a chitosan matrix reinforced with nanofibrillated cellulose (NFC). The density of the NFC–chitosan nanocomposite foams can be controlled by varying the NFC/chitosan weight ratio and solid content of the suspension in the fabrication process. The mechanical properties and thermal stability of the nanocomposite foams were significantly improved by increasing the ratio of NFC, and effective thermal insulating performance was exhibited for temperature extremes at 0 °C and 70 °C. Moreover, the NFC–chitosan nanocomposite foams showed a highly efficient oil/water separation capacity even at a severe temperature of 90 °C. In addition, the nanocomposite foams possessed good biocompatibility toward L929 mouse fibroblasts. Therefore, the bionanocomposite foams are available for a number of applications, including as disposable and high‐performance filtration media for water purification, packaging, and biological scaffolds.

Monodisperse Highly Ordered and Polydisperse Biobased Solid Foams

“…1 and 11 MPa [BAS01]. Wang et al [Wan16] showed that adding cellulose nanofibres (CNF) to a chitosan-based solution one obtains improved mechanical properties of the resulting solid foams. We thus followed a similar route to improve the mechanical strength of the monodisperse chitosan foams.…”

“…Conveniently, chitosan and CNF can be both dispersed in aqueous solutions, which facilitates the interpenetration of the chitosan chains and the CNF. As shown inFigure 2.28, Wang et al[Wan16] developed a templating method towards chitosan-CNF nanocomposite foams by freezing and freeze-drying a mixed dispersion of chitosan and CNF. This method is known as ice templating, and the pores result from the sublimation of ice crystals[Col09].…”

“…The pore morphology and anisotropy of the material can be fine-tuned by modifying the freezing conditions of the liquid mixture[Sva10,Mar16]. The addition of CNF to chitosan yields materials with better mechanical properties and thermal stability[Wan16].…”

“…The mixture is subsequently frozen to yield a solid in which chitosan and CNF are expelled out of the ice crystals. The ice crystals sublimate during freeze-drying to yield a porous chitosan-CNF nanocomposite[Wan16].Chitosan foams reinforced with CNF are not the only chitosan-CNF nanocomposites that one can produce. Fernandes et al[Fer10,Fer11] generated transparent CNF-filled chitosan films by casting mixed chitosan-CNF suspensions.…”

Fabrication and 3D Patterning of Bio‐Composite Consisting of Carboxymethylated Cellulose Nanofibers and Cobalt Ferrite Nanoparticles

“…During the past decade, efforts have been made for the development of renewable materials due to the surge to alleviate environment related concerns. Bio‐composites in this regard offer interesting properties and are relevant for a wide range of applications from flexible energy storage devices and optoelectronics to sensors, actuators, packaging and medical devices . In this regard, cellulose nanofibers (CNF) is emerging as next generation reinforcement bio‐polymer for fabrication of multifunctional bio‐composites .…”