Poly(N,N-dimethylacrylamide)-clay nanocomposite hydrogels with patterned mechanical properties

Poly(N,N-dimethylacrylamide)-clay nanocomposite gels (NC gels) with patterned network-chain density were prepared by photoinitiated radical polymerization with photomasks. The exposed region of the obtained gels showed a higher swelling ratio and lower elastic modulus than the masked region, although these regions had the same weight composition. A stripe-patterned gel prepared using a photomask with many slits of several hundred micrometers wide exhibited mechanical anisotropy: the elastic modulus in the direction parallel to the slits was higher than that in the perpendicular direction.