Fuel cell and electrolyzer using plastic waste directly as fuel.

The effective utilization of plastic waste, including its use as an energy or chemical resource, has attracted much attention. Nevertheless, energy recovery from plastics via incineration generates air pollutants and toxic compounds, while chemical conversion requires significant energy inputs, especially in the case of gasification. Herein, we report the electrochemical conversion of plastics into electricity or hydrogen without the use of special procedures. When a mixture of plastic solid combined with an acidic solution was fed into an electrochemical cell, the solid was found to dissolve in the solution at 100 °C or higher, followed by the release of protons from the anode to the cathode according to a multi-electron oxidation reaction. This oxidation reaction required an anode that was sufficiently porous so as to allow transport of the reactants. Taking the sponge sample as an example, the dissolved polyurethane had a molecular weight of 2000 or higher, the transport of which was facilitated using a carbon support with a pore diameter of approximately 10 nm. In addition, carbon black having an ordered porous structure exhibited better reagent transport compared to a disordered porous carbon black with similar pore diameters. As a consequence, this cell continuously provided power densities on the order of mW cm-2 in the fuel cell mode and generated hydrogen at a low cell voltage of 0.55 V in the electrolyzer mode, using plastics as fuels at an operational temperature of 200 °C.

Humidity Driven Transition from Insulator to Ionic Conductor in Portland Cement.

This work aims to assess ionic conduction in anhydrous cement particles and hydrated cement pastes with aging periods of 5-25 days. When a cement sample was humidified (relative humidity = 100%) over the range of 50-100 °C, it exhibited bulk conductivities of 10-3-10-2 S cm-1, regardless of the hydration level, whereas the interfacial conductivities varied in the range of 10-7-10-3 S cm-1, depending on the structural defects or conduction pathways of the sample. Both the bulk and interfacial conductivities were increased to 0.01 S cm-1 or higher at 100 °C, although the sample required previous moistening with water mist. The major charge carrier in the sample was determined to be hydroxide ions, and the total ion transport number was approximately 1. Exposing the sample to a mixture of carbon dioxide and water vapor caused a decrease in the bulk and interfacial conductivities; however, the bulk conductivity was returned to the initial value by treatment with an acid.

Rechargeable Metal-Air Proton-Exchange Membrane Batteries for Renewable Energy Storage.

Rechargeable proton-exchange membrane batteries that employ organic chemical hydrides as hydrogen-storage media have the potential to serve as next-generation power sources; however, significant challenges remain regarding the improvement of the reversible hydrogen-storage capacity. Here, we address this challenge through the use of metal-ion redox couples as energy carriers for battery operation. Carbon, with a suitable degree of crystallinity and surface oxygenation, was used as an effective anode material for the metal redox reactions. A Sn0.9In0.1P2O7-based electrolyte membrane allowed no crossover of vanadium ions through the membrane. The V4+/V3+, V3+/V2+, and Sn4+/Sn2+ redox reactions took place at a more positive potential than that for hydrogen reduction, so that undesired hydrogen production could be avoided. The resulting electrical capacity reached 306 and 258 mAh g-1 for VOSO4 and SnSO4, respectively, and remained at 76 and 91 % of their respective initial values after 50 cycles.

Kinetically driven switching and memory phenomena at the interface between a proton-conductive electrolyte and a titanium electrode.

Numerous studies have examined the switching properties of semi- or ion-conductors and isolators; however, most of these have focused on the ohmic resistance characteristics. Here, we report a new type of polarity-dependent switching phenomenon obtained for electrical devices with the configuration: metal working electrode│Si0.97Al0.03H0.03P2O7-polytetrafluoroethylene composite electrolyte│Pt/C counter electrode. The counter electrode is reversibly active for the water vapor oxidation and evolution reactions. The composite electrolyte exhibits high withstanding voltage capability in the bias voltage range of ±7 V. When titanium was employed as the working electrode, the anodic polarization resistance was approximately two orders of magnitude greater than the cathodic polarization resistance. The ohmic resistance of the device was almost unchanged, regardless of the bias voltage polarity. Moreover, kinetically induced high-resistance/low-resistance states could be cyclically switched through positive/negative bias voltage pulses, and these states were also confirmed to be memorized at open circuit.

High-temperature supercapacitor with a proton-conducting metal pyrophosphate electrolyte.

Expanding the range of supercapacitor operation to temperatures above 100 °C is important because this would enable capacitors to operate under the severe conditions required for next-generation energy storage devices. In this study, we address this challenge by the fabrication of a solid-state supercapacitor with a proton-conducting Sn(0.95)Al(0.05)H(0.05)P(2)O(7) (SAPO)-polytetrafluoroethylene (PTFE) composite electrolyte and a highly condensed H3PO4 electrode ionomer. At a temperature of 200 °C, the SAPO-PTFE electrolyte exhibits a high proton conductivity of 0.02 S cm(-1) and a wide withstanding voltage range of ± 2 V. The H3PO4 ionomer also has good wettability with micropore-rich activated carbon, which realizes a capacitance of 210 F g(-1) at 200 °C. The resulting supercapacitor exhibits an energy density of 32 Wh kg(-1) at 3 A g(-1) and stable cyclability after 7000 cycles from room temperature to 150 °C.

Randomised controlled trial evaluating the efficacy of wrap therapy for wound healing acceleration in patients with NPUAP stage II and III pressure ulcer.

Objectives To evaluate if 'wrap therapy' using food wraps, which is widely used in Japanese clinical sites, is not inferior when compared to guideline adhesion treatments. Design Multicentre, prospective, randomised, open, blinded endpoint clinical trial. Setting 15 hospitals in Japan. Patients 66 older patients with new National Pressure Ulcer Advisory Panel stage II or III pressure ulcers. Interventions Of these 66 patients, 31 were divided into the conventional treatment guidelines group and 35 into the wrap therapy group. Main outcome measures The primary end point was the period until the pressure ulcers were cured. The secondary end point was a comparison of the speed of change in the Pressure Ulcer Scale for Healing score. Results 64 of the 66 patients were analysed. The estimated mean period until healing was 57.5 days (95% CI 45.2 to 69.8) in the control group as opposed to 59.8 days (95% CI 49.7 to 69.9) in the wrap therapy group. By the extent of pressure ulcer infiltration, the mean period until healing was 16.0 days (95% CI 8.1 to 23.9) in the control group as opposed to 18.8 days (95% CI 10.3 to 27.2) in the wrap therapy group with National Pressure Ulcer Advisory Panel stage II ulcers, and 71.8 days (95% CI 61.4 to 82.3) as opposed to 63.2 days (95% CI 53.0 to 73.4), respectively, with stage III ulcers. There is no statistical significance in difference in Pressure Ulcer Scale for Healing scores. Conclusions It might be possible to consider wrap therapy as an alternative choice in primary care settings as a simple and inexpensive dressing care. Clinical Trial registration UMIN Clinical Trials Registry UMIN000002658. Summary protocol is available on https://upload.umin.ac.jp/cgi-bin/ctr/ctr.cgi?function=brows&action=brows&type=detail&recptno=R000003235&admin=0&language=J.