Graphene oxide (GO) was chemically modified with 3-aminopropyltriethoxysilane (APTES) (f-GO) and incorporated into silanized polyurethanes of two different molecular weights and chemical compositions by sol–gel reactions, and the effects were studied in terms of mechanical, dynamic mechanical, and dual and triple shape-memory polymers (DSMP and TSMP, respectively) of the nanocomposite films. It was found that the f-GO nanoparticles act as multifunctional cross-links as well as reinforcing fillers and significantly augmented the glassy and rubbery state moduli, yield strength, break strength, glass transition temperature, and dual shape-memory properties. A cohesive bilayer of the two films (lower layer and upper layer) fabricated by the interpenetrating polymer network technique exhibited synergistic mechanical properties in the glassy and rubbery states along with two undisturbed glass transitions by which an intermediate plateau region and TSMP were demonstrated.

Fe-36Ni alloy nanopowder was prepared via electrical explosion of wire in DI water. The nanopowder was reduced in hydrogen at 500 degrees C for 30 min. Spark plasma sintering at 800 and 1000 degrees C for 10 min was used to obtain bulk samples from the hydrogen-reduced nanopowder. The sintered samples were annealed at 500 degrees C for 2 h. X-ray diffraction was used to analyze the phases of the nanopowder and sintered samples. The results showed that the sintered samples were formed in gamma-(Fe-Ni) solid solution. The particles sizes and morphologies of the as-synthesized and hydrogen-reduced nanoparticles were observed via transmission electron microscopy. The morphologies of the as-synthesized nanoparticles had spherical core-shell structures. Core was gamma-(Fe-Ni) and the shell was FeO. The nanoparticles of the as-synthesized and hydrogen reduced samples were found to be nearly spherical in shape, with average diameters of 32 and 70 nm, respectively. The hysteresis loops of the as-synthesized nanopowder, hydrogen reduced nanopowder, and sintered samples revealed ferromagnetic characteristics.