A Strong Bio-Inspired Layered PNIPAM-Clay Nanocomposite Hydrogel

摘要

The demand for robust hydrogels in pharmaceutical, biomedical, and industrial applications has motivated intense research efforts in these wet polymeric materials. Recent advances have resulted in different strategies for creating highly stretchable polymeric hydrogels, including sliding-ring gels (SR gels), nanocomposite gels (NC gels), double-network gels (DN gels), macromolecular microsphere composite gels, and tetra-poly(ethylene glycol) gels. Among them, NC gels have attracted significant interest because of the simplicity of synthesis, high transparency, impressive mechanical properties, large reversible deformation, and excellent swelling and stimuli sensitivities. The high mechanical properties of NC gels are desirable for practical application in many fields. However, it remains a great technical challenge to improve mechanical properties by enhancing the content of inorganic composition. Only a few percent of inorganic clay can be incorporated into NC gels (<12wt% at most), even though special mixing or modification of clay are adopted. Further incorporation of clay leads to opacity and lower mechanical properties than the expected theoretical values resulting from the insufficiency of the nanoplatelet dispersion at high viscosity.