MICROBIOLOGICAL SURVEY ON JELLYFISH FOOD PRODUCTS: PRELIMINARY RESULTS

A microbiological survey was performed on ten brined jellyfish products, sampled in Italy from Chinese food markets. In general, the microbiological conditions were good and respected the standards contemplated in the regulations CE 2073/2005 e 1441/2007. The presence of inhibiting substances and the absence of aerobic mesophilic bacteria in two samples suggest a treatment to preserve the product

Multiscale Effect of Hierarchical Self-Assembled Nanostructures on Superhydrophobic Surface

In this work, we describe self-assembled surfaces with a peculiar multiscale organization, from the nanoscale to the microscale, exhibiting the Cassie–Baxter wetting regime with extremely low water adhesion: floating drops regime with roll-off angles < 5°. These surfaces comprise bundles of hierarchical, quasi-one-dimensional (1D) TiO2 nanostructures functionalized with a fluorinated molecule (PFNA). While the hierarchical nanostructures are the result of a gas-phase self-assembly process, their bundles are the result of the capillary forces acting between them when the PFNA solvent evaporates. Nanometric features are found to influence the hydrophobic behavior of the surface, which is enhanced by the micrometric structures up to the achievement of the superhydrophobic Cassie–Baxter state (contact angle (CA) ≫ 150°). Thanks to their high total and diffuse transmittance and their self-cleaning properties, these surfaces could be interesting for several applications such as smart windows and photovoltaics where light management and surface cleanliness play a crucial role. Moreover, the multiscale analysis performed in this work contributes to the understanding of the basic mechanisms behind extreme wetting behaviors

Synergistic effects of active sites’ nature and hydrophilicity on the oxygen reduction reaction activity of Pt-free catalysts

This work highlights the importance of the hydrophilicity of a catalyst’s active sites on an oxygen reduction reaction (ORR) through an electrochemical and physico-chemical study on catalysts based on nitrogen-modified carbon doped with different metals (Fe, Cu, and a mixture of them). BET, X-ray Powder Diffraction (XRPD), micro-Raman, X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), Scanning Transmission Electron Microscopy (STEM), and hydrophilicity measurements were performed. All synthesized catalysts are characterized not only by a porous structure, with the porosity distribution centered in the mesoporosity range, but also by the presence of carbon nanostructures. In iron-doped materials, these nanostructures are bamboo-like structures typical of nitrogen carbon nanotubes, which are better organized, in a larger amount, and longer than those in the copper-doped material. Electrochemical ORR results highlight that the presence of iron and nitrogen carbon nanotubes is beneficial to the electroactivity of these materials, but also that the hydrophilicity of the active site is an important parameter affecting electrocatalytic properties. The most active material contains a mixture of Fe and Cu

Synergistic Effects of Active Sites Nature and Hydrophilicity on Oxygen Reduction Reaction Activity of Pt-Free Catalysts

Oxygen reduction reaction (ORR) is a fundamental reaction in many electrochemical processes, but, being kinetically hindered, it requires efficient catalysts. Typically, they are based on Platinum Group Metals, that, though very efficient, present some drawbacks such as costs, availability and technological problems. Finding cheaper substitutes with similar or better electrocatalytic properties and stability is a challenge for the scientific community. Effective candidates are based on metal-nitrogen-carbon catalysts, in which metal is usually iron or cobalt. In this work we highlight the importance of the hydrophilicity of the catalyst active sites on oxygen reduction reaction through an electrochemical and physico-chemical study on catalysts based on nitrogen-modified carbon doped with different metals (Fe, Cu, and a mixture of them). BET, XRPD, micro-Raman, XPS, SEM, STEM and hydrophilicity measurements were performed. All synthesized catalysts are characterized not only by a porous structure, with porosity distribution centered in mesoporosity range, but also by the presence of carbon nanostructures. In iron-doped materials these nanostructures are bamboo-like structures typical of nitrogen carbon nanotubes, which are better organized, in larger amount and longer than those in the copper-doped material. Electrochemical ORR results show that the co-presence of iron and nitrogen carbon nanotubes is beneficial to the electroactivity of these materials, but also hydrophilicity of the active site is an important parameter affecting electrocatalytic properties. The most active material contains the mixture of Fe and Cu

Multiscale Effect of Hierarchical Self-Assembled Nanostructures on Superhydrophobic Surface

In this work, we describe self-assembled surfaces with a peculiar multiscale organization, from the nanoscale to the microscale, exhibiting the Cassie–Baxter wetting regime with extremely low water adhesion: floating drops regime with roll-off angles < 5°. These surfaces comprise bundles of hierarchical, quasi-one-dimensional (1D) TiO₂ nanostructures functionalized with a fluorinated molecule (PFNA). While the hierarchical nanostructures are the result of a gas-phase self-assembly process, their bundles are the result of the capillary forces acting between them when the PFNA solvent evaporates. Nanometric features are found to influence the hydrophobic behavior of the surface, which is enhanced by the micrometric structures up to the achievement of the superhydrophobic Cassie–Baxter state (contact angle (CA) ≫ 150°). Thanks to their high total and diffuse transmittance and their self-cleaning properties, these surfaces could be interesting for several applications such as smart windows and photovoltaics where light management and surface cleanliness play a crucial role. Moreover, the multiscale analysis performed in this work contributes to the understanding of the basic mechanisms behind extreme wetting behaviors