Fibrous Clays-based Bionanocomposites

Abstract

This lecture will introduce the latest progresses in the preparation of bionanocomposites based on fibrous clays such as sepiolite and palygorskite, assembled to biopolymers of different nature (polysaccharides, proteins and nucleic acids). Both clays are natural microfibrous silicates whose particular structural, morphological and textural features have opened the way for the preparation of a wide variety of advanced nanostructured bio-hybrid materials1including bionanocomposites of interest as structural and functional materials2. Sepiolite, and in minor extent palygorskite, included into diverse biopolymer matrices conferred interesting properties to the resulting nanocomposites offering a wide range of potential applications such as insulating fire-resistant foams, bioplastics with improving barrier properties, new nanostructured materials of interest as drug delivery systems (DDS), and others3. Adsorption of heavy metal ions and other pollutants from waste water by these bionanocomposites show their significance in environmental remediation4. DNA non-viral transfectioncan be reached with sepiolite-DNA bionanocomposites. Finally, biopolymer modified sepiolite can be efficiently used as support of viruses with application as adjuvant of vaccines. Interestingly, the bionanocomposites can be conformed as microparticulated materials (powders), beads, films and foams5showing in some cases a significant enhancement of the mechanical properties in the final materials with respect to the pristine components, which could be related to the nano-structured arrangement and the interfacial interactions between the fibrous inorganic filler and the polymeric counterpart.