Mechanism behind the Controlled Generation of Liquid Metal Nanoparticles by Mechanical Agitation.

The size-controlled synthesis of liquid metal nanoparticles is necessary in a variety of applications. Sonication is a common method for breaking down bulk liquid metals into small particles, yet the influence of critical factors such as liquid metal composition has remained elusive. Our study employs high-speed imaging to unravel the mechanism of liquid metal particle formation during mechanical agitation. Gallium-based liquid metals, with and without secondary metals of bismuth, indium, and tin, are analyzed to observe the effect of cavitation and surface eruption during sonication and particle release. The impact of the secondary metal inclusion is investigated on liquid metals' surface tension, solution turbidity, and size distribution of the generated particles. Our work evidences that there is an inverse relationship between the surface tension and the ability of liquid metals to be broken down by sonication. We show that even for 0.22 at. % of bismuth in gallium, the surface tension is significantly decreased from 558 to 417 mN/m (measured in Milli-Q water), resulting in an enhanced particle generation rate: 3.6 times increase in turbidity and ∼43% reduction in the size of particles for bismuth in gallium liquid alloy compared to liquid gallium for the same sonication duration. The effect of particles' size on the photocatalysis of the annealed particles is also presented to show the applicability of the process in a proof-of-concept demonstration. This work contributes to a broader understanding of the synthesis of nanoparticles, with controlled size and characteristics, via mechanical agitation of liquid metals for diverse applications.

Polyphenol-Mediated Liquid Metal Composite Architecture for Solar Thermoelectric Generation.

The development of advanced solar energy technologies, which efficiently convert solar energy to heat and then to electricity, remains a significant challenge in the pursuit of clean energy production. Here, this challenge is addressed by designing a photothermal absorber composed of liquid gallium particles and a natural polyphenol-based coordination ink. The design of this composite takes advantage of the tuneable light absorption properties of the polyphenol inks and can also be applied onto flexible substrates. While the ink utilizes two types of coordination complexes to absorb light at different wavelengths, the liquid gallium particles with high thermal and electrical properties provide enhanced thermoelectric effect. As such, the photothermal composite exhibits a broad-spectrum light absorption and highly efficient solar-to-heat conversion. A thermoelectric generator coated with the photothermal composite exhibits an impressive voltage output of ≈185.3 mV when exposed to 1 Sun illumination, without requiring any optical concentration, which sets a new record for a power density at 345.5 µW cm-2 . This work showcases the synergistic combination of natural compound-based light-absorbing coordination complexes with liquid metals to achieve a strong photothermal effect and their integration into thermoelectric devices with powerful light harvesting capabilities.

General Practitioners' Views on the Acceptability and Applicability of Using Quality Indicators as an Intervention to Reduce Unnecessary Prescription of Antibiotics in Four South American Countries.

As part of the quality improvement program “Health Alliance for Prudent Prescribing, Yield And Use of anti-microbial Drugs In the Treatment of respiratory tract infections” (HAPPY AUDIT) South America, we planned to implement an intervention based on the use of quality indicators as a means to influence General Practitioners’ (GPs) prescribing decision. Knowledge on the acceptability and applicability of an intervention is crucial to decide whether the intervention is suitable and will achieve the expected outcomes. This study explores GPs’ views about the acceptability and applicability of using quality indicators as an intervention to influence their prescribing decision in patients with suspected Respiratory Tract Infections (RTIs) across four countries in South-America. In March 2015, GPs that were participating in HAPPY AUDIT South America were invited to participate in focus groups. A discussion guide covering the domains acceptability and applicability was used. Data was analyzed through systematic text condensation with an inductive approach. 171 GPs were invited and 48% participated. Acceptability ranged from totally acceptable to slightly acceptable. This spectrum of GPs views on acceptability was influenced by themes concerning applicability. In conclusion, there is a positive attitude towards the use of quality indicators. Nonetheless, applicability challenges have to be taken into consideration and solved if we are to achieve a large effect with the implementation of this intervention.