A multifunctional hydrogel based on heterostructured hybrids of single-walled carbon nanotubes and clay nanoplatelets

The development of multifunction integrated hydrogels starting from inexpensive and natural precursors using environmentally friendly processes is an increasing trend in soft matter chemistry. Under this rubric, a novel hydrogel featured with almost complete inorganic components is presented. To prepare such a soft hydrated material, heterostructured hybrids (SCHybrids) electrostatically assembled from oppositely charged amine-functionalized single-walled carbon nanotubes and montmorillonite clay nanoplatelets are used as building blocks, and a well-established physical process (i.e. mechanical grinding followed by centrifugation) is adopted for gelation. The SCHybrid hydrogel thus obtained possesses multifunctional properties including high mechanical resistance, good electrical conductivity, and very low cytotoxicity. By introducing a small quantity of poly(vinyl alcohol) as binder, the composite hydrogel further develops an anti-disassembling ability, which is absent from most of physically crosslinked gels. Evaluation of biocompatibility performed using mouse fibroblast L-929 cells demonstrates that the composite hydrogel can serve as a biologically active substrate for cell culture. This work thus represents a meaningful attempt to develop multifunctional hydrogels based on the existing low-cost precursors by elaborately designing the structures of basic building blocks rather than ab initio synthesis of a new class of gelators.