Effect of gelation technique on lipid digestibility of emulsion-loaded alginate microparticles: a systematic review and meta-analysis.

Alginate microparticles fabricated via calcium gelation or layer-by-layer assembly are commonly used for encapsulating emulsions. In this study, the impact of these two gelation methods on the lipid digestibility of emulsions was reviewed through a systematic screening of relevant studies. From the literature search (Scopus, PubMed, and Web of Science databases), 604 records were screened and 25 articles were included in the analysis. The fold change of free fatty acid release rate at the end of in vitro digestion process between alginate-encapsulated emulsion and emulsions not encapsulated by alginate was calculated for calcium gelation (weighted mean of response ratio 0.64, 95% CI 0.54-0.75) and layer-by-layer assembly (weighted mean of response ratio 0.89, 95% CI 0.81-0.98). Alginate-calcium hydrogels showed stronger inhibition of the extent of lipid digestion than alginate-coated multilayer emulsions. The structural and particle size differences between alginate microparticles acquired using different techniques may contribute to this phenomenon.

Synthesis of Highly Tunable Alloy Nanocatalyst through Heterogeneous Doping Method.

The combination of supported metal nanoparticles and functional host oxides catalyze many major industrial reactions. However, uniform dispersion and ideal chemical configuration of such nanoparticles, which determines the catalytic activity, are often difficult to achieve. In this study, a unique combination is proposed of heterogeneous doping and ex-solution for the fabrication of Pt-Ni alloy nanoparticles on CeO2 . By manipulating the reducing conditions, both the particle size and composition are precisely controlled, thereby achieving a highly dispersed and stable alloy nanocatalyst. The unique behavior of controlled alloy composition is elucidated through classical diffusion and precipitation kinetics with elemental analysis of the grain boundaries. Finally, Pt-Ni alloy nanocatalysts are successfully tuned showcasing a breakthrough performance compared to single element catalyst in reverse water gas shift reaction with superior stability and reproducibility.

Nanofiber Composites as Highly Active and Robust Anodes for Direct-Hydrocarbon Solid Oxide Fuel Cells.

Direct utilization of methane fuels in solid oxide fuel cells (SOFCs) is a key technology to realize the immediate inclusion of such high-efficiency fuel cells into the current electricity generation infrastructure. However, the broad commercialization of direct-methane fueled SOFCs is critically hindered by the inadequate electrode activity and their poor longevity, which primarily stems from the carbon build-up issues. To make the technology more competitive, a novel electrode structure that can dramatically improve the tolerance against coking is essential. Herein, we present highly active and robust core-shell nanofiber anodes, La0.75Sr0.25Cr0.5Mn0.5O3@Sm0.2Ce0.8O1.9 (LSCM@SDC), directly obtained with a single-nozzle electrospinning process through the use of two immiscible polymers. The intimate coverage of SDC on LSCM not only increases the active reaction sites but also promotes resistance toward carbon deposition and thermal aggregation. As such, the electrode polarization resistance obtained with LSCM@SDC NFs is among the lowest value ever reported with LSCM derivatives (∼0.11 Ω cm2 in wet H2 at 800 °C). The facile fabrication process of such complex heterostructures developed in this work is attractive for the design of not only SOFC electrodes but also other solid-state devices such as electrolysis cells, membrane reformers, and protonic cells.

Nutraceutical potential of polyphenol-rich Sargassum species grown off the Korean coast: a review.

Sargassum, a brown seaweed, has been used traditionally as food and medicine in Korea, China, and Japan. Sargassum spp. contain bioactive substances associated with health benefits, including anti-inflammatory and antioxidant effects. Thirty Sargassum spp. inhabit the Korean coast. However, their health benefits have yet to be systematically summarized. Therefore, the purpose of this article was to review the health benefits of these 30 Sargassum spp. grown off the Korean coast based on their health benefits, underlying mechanisms, and identified bioactive compounds. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01050-x.

Gas-Permeable Inorganic Shell Improves the Coking Stability and Electrochemical Reactivity of Pt toward Methane Oxidation.

Solid oxide fuel cells produce electricity directly by oxidizing methane, which is the most attractive natural gas fuel, and metal nanocatalysts are a promising means of overcoming the poor catalytic activity of conventional ceramic electrodes. However, the lack of thermal and chemical stability of nanocatalysts is a major bottleneck in the effort to ensure the lifetime of metal-decorated electrodes for methane oxidation. Here, for the first time, this issue is addressed by encapsulating metal nanoparticles with gas-permeable inorganic shells. Pt particles approximately 10 nm in size are dispersed on the surface of a porous La0.75Sr0.25Cr0.5Mn0.5O3 (LSCM) electrode via wet infiltration and are then coated with an ultrathin Al2O3 layer via atomic layer deposition. The Al2O3 overcoat, despite being an insulator, significantly enhances the immunity to carbon coking and provides high activity for the electrochemical oxidation of methane, thereby reducing the reaction impedance of the Pt-decorated electrode by more than 2 orders of magnitude and making the electrode activity of the Pt-decorated sample at 650 °C comparable with those reported at 800 °C for pristine LSCM electrodes. These observations provide a new perspective on strategies to lower the operation temperature, which has long been a challenge related to hydrocarbon-fueled solid oxide fuel cells.

In situ synthesis of supported metal nanocatalysts through heterogeneous doping.

Supported metal nanoparticles hold great promise for many fields, including catalysis and renewable energy. Here we report a novel methodology for the in situ growth of architecturally tailored, regenerative metal nanocatalysts that is applicable to a wide range of materials. The main idea underlying this strategy is to selectively diffuse catalytically active metals along the grain boundaries of host oxides and then to reduce the diffused metallic species to form nanoclusters. As a case study, we choose ceria and zirconia, the most recognized oxide supports, and spontaneously form various metal particles on their surface with controlled size and distribution. Metal atoms move back and forth between the interior (as cations) and the exterior (as clusters) of the host oxide lattice as the reductive and oxidative atmospheres repeat, even at temperatures below 700 °C. Furthermore, they exhibit excellent sintering/coking resistance and reactivity toward chemical/electrochemical reactions, demonstrating potential to be used in various applications.

Conductive Nature of Grain Boundaries in Nanocrystalline Stabilized Bi2O3 Thin-Film Electrolyte.

Stabilized Bi2O3 has gained a considerable amount of attention as a solid electrolyte material for low-temperature solid oxide fuel cells due to its superior oxygen-ion conductivity at the temperature of relevance (≤500 °C). Despite many research efforts to measure the transport properties of stabilized Bi2O3, the effects of grain boundaries on the electrical conductivity have rarely been reported and their results are even controversial. Here, we attempt quantitatively to assess the grain boundary contribution out of the total ionic conductivity at elevated temperatures (350-500 °C) by fabricating epitaxial and nano-polycrystalline thin films of yttrium-stabilized Bi2O3. Surprisingly, both epitaxial and polycrystalline films show nearly identical levels of ionic conductivity, as measured by alternating current impedance spectroscopy and this is the case despite the fact that the polyfilm possesses nanosized columnar grains and thus an extremely high density of the grain boundaries. The highly conductive nature of grain boundaries in stabilized Bi2O3 is discussed in terms of the clean and chemically uniform grain boundary without segregates, and the implications for device application are suggested.