Polysaccharide–fibrous clay bionanocomposites

• Bionanocomposites based on fibrous clay minerals with different polysaccharides.
• Bionanocomposites provided with good mechanical properties and water resistance.
• Biocompatible and biodegradable films for retention of heavy metal ions.

The present paper introduces results on the preparation, characterization and exploration of properties of bionanocomposites prepared by the assembly of polysaccharides to sepiolite and palygorskite. The effect of the incorporation of these fibrous clay minerals was analyzed in three types of polysaccharide matrices: neutral, such as starch, and provided with either negatively or positively charged groups, such as alginate or chitosan, respectively. The effect of the amount of clay mineral and of its interaction with each type of biopolymer was analyzed by diverse physicochemical techniques. The resulting bionanocomposites processed as films exhibit not only improved mechanical properties and water resistance, but also biocompatibility and biodegradability, as well as a significant reduction of water absorption, which could make them very attractive for uses in wide variety of applications from bioplastics to adsorbents. In this work it has been also tested the retention properties of these materials towards heavy metal ions in view to enlarge the scope of their applications in the field of environmental remediation.