Multicomponent bionanocomposites based on clay nanoarchitectures for electrochemical devices

Abstract

Based on the unique ability of defibrillated sepiolite (SEP) to form stable and homogeneous colloidal dispersions of diverse types of nanoparticles in aqueous media under ultrasonication, multicomponent conductive nanoarchitectured materials integrating halloysite nanotubes (HNTs), graphene nanoplatelets (GNPs) and chitosan (CHI) have been developed. The resulting nanohybrid suspensions could be easily formed into films or foams, where each individual component plays a critical role in the biocomposite: HNTs act as nanocontainers for bioactive species, GNPs provide electrical conductivity (enhanced by doping with MWCNTs) and, the CHI polymer matrix introduces mechanical and membrane properties that are of key significance for the development of electrochemical devices. The resulting characteristics allow for a possible application of these active elements as integrated multicomponent materials for advanced electrochemical devices such as biosensors and enzymatic biofuel cells. This strategy can be regarded as an “a la carte” menu, where the selection of the nanocomponents exhibiting different properties will determine a functional set of predetermined utility with SEP maintaining stable colloidal dispersions of different nanoparticles and polymers in water.

Functional biohybrid materials based on halloysite, sepiolite and cellulose nanofibers for health applications

“…57 In this way, we have recently reported a protocol to produce multicomponent conductive bionanocomposite materials where the use of sepiolite is fundamental to achieve the stabilization of HNT dispersions in which the other components can be homogeneously incorporated. 58 In this context, the main objective of this work is to develop an alternative strategy for the preparation of a new type of multicomponent hybrid nanopaper constituted by cellulose nanofibers, sepiolite, and halloysite. Our purpose is to investigate the possibility to exploit the most important features of each component and to overcome their individual limitations in order to design a material with different chemical surfaces.…”

Improving Colloidal Stability of Sepiolite Suspensions: Effect of the Mechanical Disperser and Chemical Dispersant

“…For instance, when a sepiolite suspension in water was previously submitted to ultrasonication, under adjusted conditions, the specific surface area was found to increase from 322 to 487 m 2 •g −1 , which improved its adsorption capacity of methylene blue dye [7]. Ultrasonication has also been used as a method to generate homogeneous and stable dispersions with other materials in water for the preparation of hybrid and composite structures [8,9]. It was claimed that high energy ultrasonication can also promote the formation of thixotropic gels with highly dispersed fibrous clays, although with shorter fibers [3].…”

Nanoarchitectonics: bottom-up creation of functional materials and systems

“…Some terrific examples of the application of the nanoarchitectonics concept for engineering applications and the physical sciences include a report by Ruiz-Hitzky et al, where they summarize how photoactive clays incorporating TiO 2 and ZnO nanoparticles exhibit distinct and useful properties [35]. Other examples include a self-assembled MoS 2 -based composite that was developed for energy conversion and storage purposes [36], a silver-nanoparticle/cellulose-nanofiber composite that was applied for surface-enhanced Raman spectroscopy [37], bionanocomposites with clay nanoarchitectures for electrochemical devices [38], a biomimetic nanofluidic diode with polymeric carbon nitride nanotubes [39], and a unique Janus-micromotor applied as a luminescence sensor for sensitive TNT detection [40].…”