Near-infrared responsive shape memory hydrogels with programmable and complex shape-morphing

摘要

In this work,semi-crystalline nanocomposite hydrogels(i.e.,PAAmA_(11)A/GO gels)were synthesized by micellar copolymerization of acrylamide and N-acryloyl-11-aminoundecanoic acid(A_(11)A)in the presence of a large amount of sodium dodecyl sulfonate(SDS)micelles and GO nanosheets.The resulting hydrogels(SMHs)not only demonstrated high strength and high toughness,but also exhibited good shape memory property.Because of near-infrared(NIR)light absorbability of GO nanosheets,shape recovery and shape of PAAmA_(11)A/GO gels could be tuned by NIR irradiation.Moreover,bilayer hydrogels and trilayer hydrogels were also fabricated by the integration of shape-memorized PAAmA_(11)A/GO gel and elastic hydrophobic associated hydrogel(E-gel).Based on the NIR-responsive shape memory property and layered structure,shape deformation of bilayer hydrogels and trilayer hydrogels was rather different from the single PAAmA_(11)A/GO gel.Each kind of gel structure exhibited diverse and complex shapes via programmable NIR irradiation.More importantly,the shape morphing of NIR-SMHs-based hydrogels could mimic the hand and flower and be used as actuators.