High Shear in Situ Exfoliation of 2D Gallium Oxide Sheets from Centrifugally Derived Thin Films of Liquid Gallium

Herein, we have explored the use of a microfluidics platform for the exfoliation and oxidation of liquid gallium into ultrathin sheets of gallium oxide under continuous flow condition. The novel method developed here takes advantage of the high mass transfer in liquids and has the potential for creating high yielding thin sheets of oxidised gallium with insulating properties as well as acts as an active catalyst in hydrogen evolution reactions. This highlights the potential utility of the sheets as an alternative to the expensive and scarce noble metal based electrocatalysts

High Shear in Situ Exfoliation of 2D Gallium Oxide Sheets from Centrifugally Derived Thin Films of Liquid Gallium

Herein, we have explored the use of a microfluidics platform for the exfoliation and oxidation of liquid gallium into ultrathin sheets of gallium oxide under continuous flow condition. The novel method developed here takes advantage of the high mass transfer in liquids and has the potential for creating high yielding thin sheets of oxidised gallium with insulating properties as well as acts as an active catalyst in hydrogen evolution reactions. This highlights the potential utility of the sheets as an alternative to the expensive and scarce noble metal based electrocatalysts

Two-step continuous-flow synthesis of α-terpineol

α-Terpineol is a monoterpene naturally present in essential oils, of high value on the market as it is a compound widely used as a flavoring, aromatic substance in the cosmetics and food industry. This study aims to produce α-terpineol by two different synthetic strategies, using both batch and continuous flow systems, focusing on the optimization of the process, improving the reaction conversion and selectivity. The first strategy adopted was a one-stage hydration reaction of α-pinene by an aqueous solution of chloroacetic acid (molar ratio 1:1 between pinene and the acid) in continuous flow conditions. This reaction was carried out at 80 ºC with a residence time of 15 min, obtaining good values of conversion (72 %) and selectivity (76 %), and productivity of 0.67 Kg.day-1. The second strategy accomplished was a two-step cascade reaction with limonene as starting material, where the first step is a chemo specific double bond addition using trifluoroacetic acid, and the second step is the basic hydrolysis of the ester promoted by a solution of sodium hydroxide (2.25 M) in methanol (1:1). This reaction was adapted to a continuous flow condition, where all steps happen in a residence time of 40 min, at 25 ºC, with no quenching between steps required, giving a conversion of 97 % and selectivity of 81 %, with productivity of 0.12 Kg.day-1.

The Impact of Pulsatile Flow on Suspension Force for Hydrodynamically Levitated Blood Pump

Hydrodynamically levitated rotary blood pumps (RBPs) with noncontact bearing are effective to enhance the blood compatibility. The spiral groove bearing (SGB) is one of the key components which offer the suspension force to the RBP. Current studies focus on the suspension performance of the SGB under continuous flow condition. However, the RBP shows pulsatile characteristics in the actual clinical application, which may affect the suspension performance of the SGB. In this paper, the impact of pulsatile flow upon the suspension force from the SGB is studied. A model of the SGB with a groove formed of wedge-shaped spirals is built. Then, the CFD calculation of the hydrodynamic force offered by designed SGB under simulated pulsatile flow is introduced to obtain the pulsatile performance of the suspension force. The proposed method was validated by experiments measuring the hydrodynamic force with different bearing gaps. The results show that the suspension force of the SGB under pulsate flow is the same as under steady flow with equivalent effective pressure. This paper provides a method for suspension performance test of the SGB.

A paper-based microbial fuel cell operating under continuous flow condition

Microbial fuel cells have gained popularity as a viable, environmentally friendly alternative for the production of energy. However, the challenges in miniaturizing the system for application in smaller devices as well as the short duration of operation have limited the application of these devices. Here, the capillary motion was employed to design a self-pumped paper-based microbial fuel cell operating under continuous flow condition. A proof-of-concept experiment ran approximately 5 days with no outside power or human interference required for the duration of operation. Shewanella oneidensis MR-1 was used to create a maximum current of 52.25 µA in a 52.5 µL paper-based microfluidic device. SEM images of the anode following the experiment showed biofilm formation on the carbon cloth electrode. The results showed a power density of approximately 25 W/m3 and proved unique capabilities of the paper-based microbial fuel cells to produce energy for an extended period of time.

Synthesis of V2O5 Nanoflakes on PET Fiber as Visible-Light-Driven Photocatalysts for Degradation of RhB Dye

The visible-light-driven semiconductor photocatalysts are the current research focus techniques used to decompose organic pollutants/compounds. The photodegradation efficiency of organic compounds by photocatalyst is expected to be better compared to UV-light-driven semiconductor photocatalysts technique since the major components of our solar energy are visible light (~44%). However, as most of the previous research work has been carried out using semiconductor photocatalysts in the form of powder, extra steps and costs are needed to remove this powder from the slurry to prevent secondary pollution. In this research work, we will explain our fabrication technique of V2O5 nanoflakes by growing radially on PET fibers. By utilizing the flexibility and high surface area of polymeric fibers as novel substrate for the growth of V2O5 nanoflakes, the Rhodamine B (RhB) could be degraded under visible light irradiation. The photodegradation of RhB solution by V2O5 nanoflakes followed the 1st order kinetic with a constant rate of 0.0065 min−1. The success of this research work indicates that V2O5 nanoflakes grown on PET fibre could be possibly used as organic waste water purifier under continuous flow condition. A photodegradation mechanism of V2O5 nanostructures to degrade RhB dye is proposed based on the energy diagram.