Swelling-Induced Quaternized Anthrone-Containing Poly(aryl ether ketone) Membranes with Low Area Resistance and High Ion Selectivity for Vanadium Flow Batteries.

A vanadium flow battery (VFB) is one of the most promising electrochemical energy storage technologies. However, membranes for VFBs still suffer from high cost or low conductivity and poor stability. Here, we report new quaternized anthrone-containing poly(aryl ether ketone) (QAnPEK) membranes for VFBs. QAnPEK membranes with moderate ion exchange capacity (1.26 mmol g-1) were swelling-induced in H3PO4 (50 wt %) to form wider ion transport pathways that significantly enhanced membrane conductivity (e.g., 0.49 Ω cm2 for the QAnPEK-virgin membrane and 0.12 Ω cm2 for the swelling-induced QAnPEK-90 membrane). The bulky rigid anthrone-containing backbone provided high swelling resistance and enabled QAnPEK membranes to have high ion selectivity. As a result, QAnPEK membranes displayed low area resistance, high ion selectivity, and robust mechanical strength. The QAnPEK-90 membrane yielded excellent energy efficiencies (92.4% at 80 mA cm-2, 85.1% at 200 mA cm-2, and 80.3% at 280 mA cm-2). Moreover, QAnPEK membranes exhibited outstanding in situ and ex situ stability, for example, the VFB with the QAnPEK-40 membrane demonstrated highly stable battery performance for 3000 cycles at 160 mA cm-2. QAnPEK membranes are attractive candidates for VFB application.

Robust Adamantane-Based Membranes with Enhanced Conductivity for Vanadium Flow Battery Application.

Membranes with high conductivity, high selectivity, and high stability are urgently needed for high-power-density vanadium flow batteries (VFBs). Enhancing membrane conductivity presents many challenges, often resulting in sacrificing membrane selectivity and mechanical strength. To overcome this, new robust adamantane-based membranes with enhanced conductivity are constructed for VFB. Low-content basic piperazine (IEC = 0.78 mmol g-1) and hydrophilic hydroxyl groups are introduced into highly rigid, hydrophobic adamantane containing poly(aryl ether ketone) backbone (PAPEK) and then selectively swelled to induce microphase separation and form ion transport pathways. The highly rigid and hydrophobic PAPEK exhibits high swelling resistance and provides the membranes with slight swelling, high selectivity, and high mechanical strength. The selective swelling temperature has a significant influence on the areal resistance of the resulting membrane, e.g., the PAPEK-130 membrane, when selectively swelled at 130 °C, has low areal resistance (0.22 Ω∙cm2), which is approximately two-fifths that of the PAEKK-60 membrane (treated at 60 °C, 0.57 Ω∙cm2). Consequently, the resulting PAPEK membranes exhibit low swelling, high selectivity, and low areal resistance, with the VFB constructed with a PAPEK-90 membrane exhibiting excellent energy efficiency (91.7%, at 80 mA∙cm-2, and 80.0% at 240 mA∙cm-2) and stable cycling performance for 2000 cycles.

Disinfection efficiency of positive pressure respiratory protective hood using fumigation sterilization cabinet.

Concerns have been raised about both the disinfection and the reusability of respiratory protective equipment following a disinfection process. Currently, there is little data available on the effects of disinfection and decontamination on positive pressure respiratory protective hoods (PPRPH). In this study, we evaluated the effect of vaporized hydrogen peroxide (VHP) on the disinfection of PPRPH to determine applicability of this method for disinfection of protective equipment, especially protective equipment with an electric supply system. A hydrogen peroxide-based fumigation sterilization cabinet was developed particularly for disinfection of protective equipment, and the disinfection experiments were conducted using four PPRPHs hung in the fumigation chamber. The pathogenic microorganism Geobacillus stearothermophilus ATCC 7953 was used as a biological indicator in this study and the relationship between air flow (the amount of VHP) and disinfection was investigated. Both function and the material physical properties of the PPRPH were assessed following the disinfection procedure. No surviving Geobacillus stearothermophilus ATCC 7953, both inside and outside of these disinfected PPRPHs, could be observed after a 60 min treatment with an air flow of 10.5-12.3 m3/h. Both function and material physical properties of these PPRPHs met the working requirements after disinfection. This study indicates that air flow in the fumigation chamber directly influences the concentration of VHP. The protective equipment fumigation sterilization cabinet developed in this paper achieves the complete sterilization of the PPRPHs when the air flow is at 10.5-12.3 m3/h, and provides a potential solution for the disinfection of various kind of protective equipment.

Development of a negative pressure hood for isolation and transportation of individual patient with respiratory infectious disease.

The frequent and sudden occurrence of both known and unknown infectious diseases can cause global social panic. If the source of infection can be effectively controlled in the early stages of an outbreak, the spread of infectious diseases can be prevented. In view of this situation, this study developed for infectious or suspected infectious patients a negative pressure isolation hood which effectively achieves direct individual isolation during the early stages of disease outbreak, and facilitates long-distance transport. The hood body is made of flexible transparent polyvinyl chloride (PVC) material, and the combination of the hood material is airtight. The unique inflatable column support structure and the design of the inflatable neck sleeve effectively ensure both stiffness and air tightness of the hood body. The electrical exhaust system maintains a stable negative pressure environment inside the hood, and polluted air inside the hood can be purified by a high efficiency filter. Test results showed that the internal noise of the hood was 68 ± 1 dB (A), the air exhaust volume of the electric exhaust system was not <200 L/min, and the filtration efficiency of the filter to 0.3 µm particles was >99.99%, indicating that the hood achieved effective isolation protection for patients with respiration infectious diseases.

Two-dimensional nickel hydroxide/sulfides nanosheet as an efficient cocatalyst for photocatalytic H2 evolution over CdS nanospheres.

The intriguing features of two-dimensional (2D) materials such as better charge carrier separation and abundant surface reaction sites endow them with potential applications as cocatalysts in photocatalysis. In this paper, a ternary 2D nickel hydroxide/sulfides nanosheet composed of Ni(OH)2, Ni3S2 and NixS6 was loaded on CdS nanospheres by a simple chemical deposition route. The composition of nickel hydroxide/sulfides was determined clearly through an overall analysis using X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. Mott-Schottky, electrochemical impedance, steady-state and time-resolved photoluminescence spectroscopy were used to investigate the charge transfer process in CdS and Ni(OH)2/Ni3S2/NixS6-CdS. The results confirm that a synergistic effect of Ni(OH)2/Ni3S2/NixS6 on CdS has occurred under light irradiation, where the Ni(OH)2 and nickel sulfides act as hole storage and surface reaction sites, respectively, to promote the charge transfer on CdS. The improved charge transfer and separation efficiency as well as the increased surface reaction sites in Ni(OH)2/Ni3S2/NixS6-CdS finally result in a dramatically improved photocatalytic performance. The photocatalytic H2 evolution rate of Ni(OH)2/Ni3S2/NixS6-CdS is ca. 46 times higher than that of CdS, and the photocatalytic stability of CdS is also improved substantially under visible light irradiation.

Efficient Fenton Oxidation of Congo Red Dye by Magnetic MgFe2O4 Nanorods.

We reported a highly active magnetic MgFe2O4 nanorods catalyst by annealing Mg(OH)2 deposited α-FeOOH nanorods. The catalyst was fully characterized by X-ray diffraction (XRD), High Resolution Transmission Electron Microscopy (HRTEM), and Vibrating Sample Magnetometer (VSM), and the results showed that the magnetic MgFe2O4 nanorods were a diameter of 50 nm. The as-prepared MgFe2O4 nanorods were used to catalyze Fenton oxidation of Congo red (CR) solution, and the degradation rate of CR reached 95% after 2 h. The catalytic activity remained high after five cycles. The magnetic MgFe2O4 nanorods could be easily separated from organic solvent. The effects of parameters such as temperature, dosage of catalyst, and H2O2 were also analyzed. This opens new perspectives for the synthesis of one-dimensional magnetic catalyst based on a template method and effective treatment of aqueous hazardous dye.