Binary transition metal oxides, such as NiCo2O4 (NCO) electrode have been demonstrated to be promising candidates for high-performance supercapacitors. However, their low electrical conductivity and poor stability made the electrochemical performance of most current NCO electrodes yet below the expectation. Herein, a novel electrode (NCC) consisting of binary transition metal (Ni–Co) nanoparticles embedded N-doped porous carbon matrix on graphite papers (GPs) has been developed with a high specific capacitance of 933.5 F/g at 1 mA/cm2 which is substantially 10 times than that of the NCO electrode (99.3 F/g) and much higher than those of most reported NCO based electrode. Moreover, this NCC electrode has an ultrahigh rate capability of 725.5 F/g at 10 mA/cm2 with excellent electrochemical durability (no capacitance decreases after 10,000 cycles). These results indicate a promising potential application of Ni–Co metal composite embedded carbon matrix for using as an effective electrode material in supercapacitors.

The large strain extrusion-machining process has been used to refine the microstructure in a Titanium alloy (Ti–6Al–4V). The unconstrained cutting or machining of Ti–6Al–4V entails the formation of shear localized chips at nearly all cutting speeds, thereby hindering the use of extrusion-machining to produce fine-grained materials. The present effort attempts to suppress shear localization by the suitable modification of texture in Ti–6Al–4V through the cold-rolling process prior to extrusion-machining. Ti–6Al–4V plates were cold rolled to 30, 40, 45, and 47% thickness reductions. These textured plates were extrusion machined using a suitably designed fixture leading to fine-grained continuous foils with increased hardness. Microscopy has revealed that the suppression of shear localization in the foils produced from plates which are cold rolled to more than 40% of thickness reduction is triggered by texture formation. For thickness reductions slightly lower than 40% (e.g., 30%), suppression can be achieved only by a combination of texture and extrusion.

In this article, we report the synthesis of highly packed graphene oxide-based electrodes (1.25 g/cm3) with a three-dimensional multiscale porous structure (denoted as MPGP) through the ZnO nanodisk (100–500 nm) template and subsequent H2O2 treatment. Consequently, MPGP with a macropore diameter of 100 nm and a mesopore diameter of 2–3 nm was fabricated as the electrode for supercapacitors (SCs). Significantly, the MPGP achieves a high-volumetric capacitance of 327 F/cm3 (262 F/g) at a current density of 1 A/g and retains 240 F/cm3 (192 F/g) at a current density of 16 A/g in 3 M KOH solution. More importantly, it was also capable of delivering a high-volumetric energy density as well as power density in a SC device. Our work shows that the capability of preparing highly packed graphene-based electrodes with high-volumetric as well as specific capacitance is critical for the application of SCs.

A hierarchical porous carbon with bimodal pore size distribution was synthesized using pyrolysis and controlled activation of polymer gel derived from furfuryl alcohol and phloroglucinol using a soft templating approach. Symmetric capacitors made using the synthesized carbon electrodes in neat 1-butyl 3-methylimidazolium tetrafluoroborate showed a specific capacitance of 141 F/g at 1 A/g when cycled between 0 and 3.8 V at room temperature. The capacitor also showed 90% capacitance retention over 5000 cycles. Equivalent circuit modeling of impedance spectra was done to monitor changes and provide microstructural details during cycling and temperature studies. Cyclic voltammetry showed the presence of specific adsorption of the electrolyte ions on the carbon electrode and this was in good agreement with strong dependence of specific capacitance on temperature. Such strong interaction along with the nature of electrical double layer formed in the hierarchical porous carbon results in widening the voltage stability window of the capacitor.

Porous carbon nanomaterials with significant capacitive performance were successfully prepared through a simple two-step process of thermal-polymerization and carbonization without an additional template. As a result, the as-prepared porous carbon nanomaterials of sample-A and sample-B exhibited an amorphous phase with low graphitization. And sample-A showed a moderate specific surface area of 476.39 m2/g, larger than that of sample-B (280.94 m2/g). The relatively high mass specific capacitance of 205.1 F/g at a scan rate of 5 mV/s and 211 F/g at a current density of 4 A/g was obtained by sample-A, which are higher than those of sample-B (82.6 F/g at 5 mV/s and 78.6 F/g at 4 A/g). Sample-A also showed excellent conductivity and superior cyclic stability with 94.19% capacitance retention after 5000 cycles, which are also higher than those of sample-B. This work proposed a cost-effective, green, and promising strategy for the large-scale preparation of porous carbon nanomaterial electrodes.

In this work, we report on the adhesion of HCT116 (human colon carcinoma cells) cultured on nanofibrillar polymethylmethacrylate (PMMA) and SU-8 micropillars substrates. Both surfaces enabled a good cell proliferation and promoted the formation of adherent interconnections with the fabricated nano- and microstructures. The three-dimensional immunofluorescence confocal characterization of the cells on nanotextured PMMA highlighted the expression of well-spread F-actin cytoskeletal networks as well as the presence of focal adhesions. This study provides thus interesting perspectives for further investigations on the force/adhesion mechanisms related to cancer cell growth and proliferation.

In this paper, corrosion behaviors of Mg–10Gd–5Y–2Zn–0.5Zr (wt%) alloy (GWZ1052K) in different aging stages are investigated using immersion tests and electrochemical measurements in 3.5 wt% NaCl aqueous solution. The corrosion resistance is found to increase from the solution-anneal to peak-aged condition, which is attributed to microstructure evolutions of β′ precipitates and nearly unchanged long period stacking ordered (LPSO) structures. The broken network LPSO structures no more act as corrosion barriers, thus inversely worsening the galvanic corrosion. β′ precipitates uniformly surround the LPSO lamellas, those partly enhancing corrosion resistance. The potentiodynamic polarization curves also show the best corrosion resistance in the peak-aged stage, suggesting the similar tendency of corrosion behaviors. And the results of electrochemical impedance spectrum are consistent with the morphology of the corrosion surface. Further equivalent circuit is established to investigate the corrosion mechanism.

The effect of Si on Fe-rich intermetallic formation and the mechanical properties of the heat-treated squeeze cast Al–5.0Cu–0.6Mn–0.7Fe alloy was investigated. Our results show that increasing the Si content promotes the formation of Al15(FeMn)3(SiCu)2 (α-Fe) and varies the morphology of T (Al20Cu3Mn2), where the size decreases and the amount increases. The major reason is that Si promotes heterogeneous nucleation of the intermetallics leading to finer precipitates. Si addition significantly enhances the ultimate tensile strength and yield strength of the alloys. The strengthening effect is mainly owing to the dispersoid strengthening by increasing the volume fraction of the T phase and less harmful α-Fe with a compact structure, which makes it more difficult for the cracks to initiate and propagate during tensile test. The squeeze cast Al–5.0Cu–0.6Mn–0.7Fe alloy with 1.1% Si shows significantly improved mechanical properties than the alloy without Si addition, which has a tensile strength of 386 MPa, yield strength of 280 MPa, and elongation of 8.6%.

Heteroatom-doped carbon materials have attracted immense interest as advanced supercapacitor electrode materials due to their unique properties. A carbon cloth-supported, nitrogen-doped carbon “spider web” network full of macropores and mesopores is developed via the pyrolysis of polyaniline nanofibers in ammonia atmosphere. The presence of mesopores and macropores can provide ion-buffering reservoirs to shorten the ion diffusion distance to the interior part of the carbon network. Carbonization in ammonia introduced N heteroatoms through gas phase chemical reactions between ammonia and the oxygen functionalities on the carbon surface. The enhanced ion-accessible surface area and improved charge transfer rate can be achieved. The N-doped carbon “spider web” exhibited a high specific capacitance of 266 F/g at a scan rate of 2 mV/s. Even when the scan rate was increased to 500 mV/s, 61% of its capacitance could still be retained, evidencing its excellent rate performance. The demonstrated strategy is anticipated to be generally effective for preparing heteroatom-doped carbon electrodes with other polymers.