Formation of Nanolayer on Surface of EPD Coatings Based on Poly-Ether-Ether-Ketone

Poly-ether-ether-ketone (PEEK) is a high performance polymer with many intrinsic properties. When it is used in the form of coating, an improvement of some of its functional properties was achieved by forming a surface nanolayer. In this chapter, it will be described how it was possible to obtain this result. Firstly, three kinds of PEEK composite coatings were deposited by electrophoretic deposition, adding alumina particles, polytetrafluoroethylene (PTFE) and lignin to PEEK. Then, the composite coatings were thermal treated in a furnace. Therefore, surface nanostructure and chemical composition of these PEEK composite coatings were modified with respect to bulk coatings, due to interaction between PEEK chain and secondary phase, emphasised by the thermal treatment conditions. Experimental evidence of the formation of surface nanolayer was provided by SEM, TEM, GIXRD, ATR-FTIR and XPS characterisations. Functional characterisations demonstrated that wear resistance—in the presence of alumina particles—hydrophobicity—in the presence of PTFE—and corrosion resistance—in the presence of Lignin—were increased with respect to pure PEEK

Numerical Study of Anaerobic Digestion System for Olive Pomace and Mill Wastewater

Abstract This work aims to develop an anaerobic digestion system, which allows recovering energy from olive wastes, solving the problem of their disposal. To reach this result, polyphenols, which are contained in olives inhibiting the digestion process, have to be abated. For this reason a new anaerobic digestion system able to treat the high concentration of polyphenols has been studied. Particularly, this system, composed by a storage of olive pomace, a mixing/washing unit, a pomace/water separation unit (decanter), an ultrafiltration unit and an anaerobic digester, has been numerically investigated to evaluate the anaerobic digestion key variables as a function of the hydraulic retention time (HRT), as well as the production of biogas for different values of the biomass yield factor. The results revealed that by abating polyphenols, the methane potential of the system under investigation rises from 7.5 molCH 4 /kgTSS to 11.7 molCH 4 /kgTSS, with an increment of about 56%, for HRT equal to 30 days

A novel group of polyhydroxycholanic acid derivatives from the deep water starfish Styracaster caroli

Three novel polyhydroxysteroid constituents have been isolated from the starfish #Stracaster caroli$ collected at a depht of 2000 m off New Caledonia. These, designated carolisterols A - C (1 - 3), are characterized by a polyhydroxycholanic acid moiety, in which the 24-carboxylic acid function is found as an amide derivative ofD-cysteinolic acid. (Résumé d'auteur

Photoreduction of Carbon Dioxide to Formic Acid in Aqueous Suspension: A Comparison between Phthalocyanine/TiO2 and Porphyrin/TiO2 Catalysed Processes

Composite materials prepared by loading polycrystalline TiO2 powders with lipophilic highly branched Cu(II)- and metal-free phthalocyanines or porphyrins, which have been used in the past as photocatalysts for photodegradative processes, have been successfully tested for the efficient photoreduction of carbon dioxide in aqueous suspension affording significant amounts of formic acid. The results indicated that the presence of the sensitizers is beneficial for the photoactivity, confirming the important role of Cu(II) co-ordinated in the middle of the macrocycles. A comparison between Cu(II) phthalocyanines and Cu(II) porphyrins indicated that the Cu(II)- phthalocyanine sensitizer was more efficient in the photoreduction of CO2 to formic acid, probably due to its favorable reduction potential