Programing polyurethane with rational surface-modified graphene platelets for shape memory actuators and dielectric elastomer generators. (15th June 2020)

• Record Type: Journal Article
• Authors: Panahi-Sarmad, Mahyar; Abrisham, Mahbod; Noroozi, Mina; Goodarzi, Vahabodin; Arjmand, Mohammad; Sadri, Mahdi; Dehghan, Parham; Amirkiai, Arian; Khonakdar, Hossein Ali
• Is Part Of: European polymer journal. Volume 133(2020)
• Publication Date: 2020-06-15
• Subjects: Dielectric elastomer generator -- Shape memory -- Polymer nanocomposite-microstructure -- Graphene-oxide & reduced graphene-oxide -- Noncovalent functionalization; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; Polymerization; Polymers; Periodicals; Electronic journals; 547.705
• DOI: 10.1016/j.eurpolymj.2020.109745
• Languages: English
• ISSNs: 0014-3057

Abstract

Graphical abstract: Highlights: Three kinds of graphene-filler with divers surface chemistry were fabricated: graphene oxide (GO), reduced graphene oxide (rGO) and functionalized graphene oxide (XGO). The surface chemistry and thermodynamic affinity of fillers play a vital role in the microstructure-property of PU nanocomposites. The effect of microstructure of PU nanocomposites in mechanical and electrical properties, as well as dielectric generation and shape memory behaviour, was systematically studied. PU nanocomposites containing functionalized filler (XGO) exhibited the highest potential applications for dielectric elastomer generators. PU nanocomposites comprising functionalized (XGO) and hybrid (GO:rGO) fillers compare in initial criteria to design the best system for shape memory and generation performance. Abstract: The filler network in smart nanocomposites is capable of dictating the strain actuation and electric generation behaviour in shape-memory and dielectric-elastomer systems, respectively. Noteworthy, the dissipation parameters, such as loss modulus and dielectric loss, are the critical criteria for designing an ideal smart polymeric composite. For manipulating dissipation parameters, we developed three types of nanofiller, including (I) simple graphene-oxide (GO), (II) reduced graphene-oxide (rGO), and (III) noncovalent-factionalized graphene with (polyamine-anchored)-perylene-bisimide (XGO). After fabrication of poly-urethane (PU) nanocomposites at various filler loading, the robust correlation between microstructure, electrical and mechanical, including static and dynamic (linear and nonlinear viscoelasticity), properties of nanocomposites has been deduced. These smart polymeric nanocomposites demonstrate the capability of shape-memory actuating as well as harvesting the electric energy from mechanical work. First and foremost, the harvested-energy-density of PU was meaningfully improved when blended with XGO. A composite-film containing 5 wt% XGO with the harvested energy density of 2.97 mJ/cm 3 was achieved, which is about 6.7 times superior to that of pristine PU. Furthermore, the shape-memory recovery ratio of functionalized 2 wt%-nanocomposite significantly improved from 86.2% for pure PU to 93.4% for the XGO sample. The observations in this work strongly suggest compositing is an auspicious-way to provide proper shape-memory actuator and better dielectric-elastomer candidates for forthcoming practical generators.