Due to an extremely low permittivity, silicone based dielectric elastomer actuator (DEA) needs to be triggered by a very high voltage, thus endures the risks of electrical breakdown and creep rupture. To address this problem, polydimethylsiloxane (PDMS) encapsulated carbon black (PCB) particles are filled in a vinylsilane-rich silicone (VRS) to obtain a hybrid PCB/VRS film with enhanced mechanical and insulation properties. The detected Young's modulus and dielectric permittivity of the hybrid film containing 5.82 vol% PCB increase by 613 and 244% compared to the pure film, respectively. PDMS' encapsulation effectively prevents the adjacent PCB particles forming conductive networks, thus the resultant PCB/VRS composite presents an enhanced breakdown strength of 63.31 V/mu m and an attenuated dielectric loss of 0.078, which benefit DEA working. Triggered by a relatively low electrical field of 7.14 V/mu m, the hybrid DEA exhibits better out-of-plane actuations compared to the pure DEA: 1.91-fold in flection amplitude, 2.79-fold in areal strain, and 4.35-fold in force output.

Ionic polymer metal composite (IPMC) always takes big risks of electrode cracking and peeling, which lead to energy wasting, waterloss, and uneven electric field distribution, thus hamper its commercial applications. To address this issue, we propose a facile and effective technique to repair the electrode fatigue by coating polyvinylpyrrolidone (PVP) encapsulated Ag nanoparticles (PVP@AgNPs) on the long-term used IPMC surface. To improve the electrochemical stability, the silver nanoparticles (Ag NPs) with a diameter of ∼34 nm are encapsulated by a 1.3 nm thick PVP film, thus forming a shell–core structure to resist corrosion from the electrolyte solution. Physiochemical investigations reveal that, PVP@AgNPs closely attach to the interior and exterior surfaces of the original Pt nanograin electrode, thus refreshing its electronic conductivity; the repaired IPMC actuator exhibits better electromechanical properties compared to its precursor actuator: 7.62 folds in displacement output, 9.38 folds in force output, and 9.73 folds in stable working time.

以有机锡为催化剂、异佛尔酮二异氰酸酯(IPDI)为偶联剂,将端羟基-聚二甲基硅氧烷(HO-PDMS)接枝到氧化石墨烯(GO)的表面,制备了硅烷化氧化石墨烯(SGO).红外光谱、拉曼光谱和X射线光电子能谱结果证明了HO-PDMS的成功接枝.通过扫描电子显微镜观测到SGO均匀分散在硅橡胶(PDMS)基体中,由此得介电常数和力学性能提升的SGO/PDMS复合膜.当添加10 phr SGO后,复合膜的相对介电常数达到3.076,较纯PDMS膜增加了40.7％.在复合膜两侧涂覆柔性PDMS/炭黑电极,制备了SGO/PDMS膜介电弹性体电致动器(DEP).该致动器在4.71 V/μm(2 Hz)的低压电场下发生面外弯曲振动,中心偏转位移达到0.654 mm,折合膜形变率为5.42％,在文献已报道的同类产品中处于较高水平.

A 3D porous graphene composite film containing Ni/NiO hybrid nanoparticles (Ni/NiO NPs) is prepared by combining electrophoresis deposition and thermal H(2)annealing techniques. The Ni/NiO NPs with a mean diameter of 45 nm are uniformly embedded on both the exterior and interior surfaces of reduced graphene, forming a 3D porous reduced graphene oxide composite film (Ni/NiO rGO). The insertion of Ni/NiO NPs into rGO greatly improves the electric conductivity and charge storage capability of the resultant Ni/NiO rGO film. By directly using it as freestanding electrodes, the fabricated lithium-ion battery and supercapacitor respectively exhibited high capacities of 758 mAh g(-1)@ 0.2 A g(-1)and 430.8 F g(-1)@0.5 A g(-1), an increase of 82.3-fold and 20.2-fold compared to the pure rGO electrode-based counterparts under the same condition.

A unique electrode architecture consisting of Ni3Se2 nanosheet-on-Ni3Se2-nanoforests grown on nickel foam was obtained by a simple one-step solvothermal method, which subsequently used as a free-standing electrode for supercapacitor. The Ni3Se2 exhibited a high capacity of up to 600 μAh cm−2 at 3 mA cm−2, excellent rate capability and cycling stability at high cycling rates. Impressively, the optimized hybrid supercapacitor containing Ni3Se2 cathode still released 94.4% of initial capacity for 505 μAh cm−2 after 6000 cycles at 20 mA cm−2. The results suggest that the Ni3Se2 nanoforests developed electrode has great potential for practical applications in hybrid supercapacitors.

This study provides a facile and effective strategy to fabricate sulfonic SiO2 nanocolloid (HSO3-SiO2) doped perfluorosulfonic acid (PFSA) films with enhanced water uptake and inner channel for high-performance and cost-effective ionic exchange polymer metal composite (IPMC) actuators. A commercial precursor of mercaptopropyl trimethoxysilane was hydrolyzed to form thiol functionalized SiO2 nanocolloids (SH-SiO2, ∼25 nm in diameter), which were further oxidized into sulfonic SiO2 nanocolloids (HSO3-SiO2, ∼14 nm in diameter). Both SiO2 nanocolloids were used as additives to dope PFSA film for fabricating IPMC-used matrix films. Due to difference of compatibility, the SH-SiO2 nanocolloids take phase separation in the cocrystallization course, and aggregate into huge, regular spherical particles with a mean diameter of ∼690 μm; while the HSO3-SiO2 nanocolloids are completely compatible with PFSA, forming a very homogeneous hybrid matrix film. Related physiochemical investigations by analytical tools revealed that, the resultant HSO3-SiO2 hybrid film shows better IPMC-related properties compared to the SH-SiO2 hybrid film: 1.59 folds in water uptake, and 2.37 folds in ion exchanging capacity, thus contains an increased number of cations and possesses larger and better interconnected inner channels for IPMC bending. Consequently, the HSO3-SiO2 hybrid IPMC actuator exhibits remarkably higher levels of actuation behaviours such as higher force output, higher displacement output, and longer stable working time, which could be used as a valuable artificial muscle for flexible actuators or displacement/vibration sensors at low cost.