A facile approach towards highly tough and stretchable Laponite-based nanocomposite hydrogels
Laponite sheets have been widely used for the preparation of tough nanocomposite hydrogels for enticing applications, however, their inferior dispersion in aqueous media resulting from the electrostatic interactions between the nanosheets remarkably limits further improvements on the mechanical performances of the nanocomposite hydrogels. Here we show a simple approach to dramatically accelerate the dispersion of Laponite sheets in water, and in turn further improve the mechanical performances of the resulting nanocomposite hydrogels. Upon addition of poly(acrylic acid) (PAA), the electrostatic interactions between Laponite sheets were effectively reduced due to the adsorption of PAA onto the positively charged edges of Laponite sheets, thereby accelerating the dispersion of Laponite sheets in water. On this basis, a series of polyacrylamide (PAAm) hydrogels with high content of Laponite sheets were prepared, showing excellent tensile strength, stretchability, and anti-fatigue property. This study would be beneficial to the preparation of Laponite-based nanocomposite hydrogels bearing excellent mechanical properties for new applications.