Bioinspired Environmentally Friendly Amorphous CaCO3?BasedTransparent Composites Comprising Cellulose Nanofibers

摘要

Amorphous calcium carbonate (ACC) stabilizedby acidic macromolecules is a useful material for the developmentof environmentally friendly composites. In this study, wesynthesized transparent and mechanically tough ACC-basedcomposite materials by the incorporation of water-dispersiblecellulose derivatives, namely, carboxymethyl cellulose (CMC) andsurface-modified crystalline cellulose nanofibers (CNFs). Asolution mixing method used in the present work proved to bea powerful and efficient method for the production ofmechanically tough and environmentally friendly materials.Molecular-scale interactions between carboxyl groups and Ca2+ions induce homogeneous dispersion of CNFs in the composites,and this gives composite films with high transparency and highmechanical properties. The composite films of CMC, CNFs, andACC at the mixture ratios of 40,40,and 20wt%, showed high mechanical properties of 15.8±0.93 GPa for the Young’smodulus and 268±20 MPa for the tensile strength. These designed materials that are based on ACC may open up newopportunities in many fields in applications that require the use of environmentally friendly, biodegradable, mechanically tough,and transparent composite materials.