A competitive sensing system based on cyclobis(paraquat-p-phenylene) and a new β-cyclodextrin-tetrathiafulvalene derivative

We report the synthesis of 4,5-di(ethylthio)-4′-[6-deoxy-β-cyclodextrin-6-yl-aminocarbonyl]-tetrathiafulvalene (β-CD-DET-TTF) and its inclusion abilities towards cyclobis(paraquat-p-phenylene) (CBPQT4+ ) and 1-naphthol. The structure of the synthesised compound has been established by mass spectrometry and 1H NMR spectra combined with a theoretical MM3 and AM1 study. The sensor affords a charge transfer (CT) complex with the CBPQT4+ and is able to include 1-naphthol in the cyclodextrin cavity. The complexes were characterised experimentally by UV–vis spectroscopy and simulated by a MM3 docking procedure. The sensing ability of the β-CD-DET-TTF/CBPQT4+ complex towards 1-naphthol has been investigated by a competitive spectral method. The synthesis and characterisation of a new water soluble β-CD-DET-TTF derivative able to formed a CT complex with the CBPQT4+ acceptor is reported. The water soluble CT complex β-CD-DET-TTF/CBPQT4+ could be used as an efficient sensor towards aromatic guests prone to give inclusion complexes with the CBPQT4+ ring

Properties of Galvanized and Galvannealed Advanced High Strength Hot Rolled Steels

The objectives of the project were (i) to develop the coating process information to achieve good quality coatings on 3 advanced high strength hot rolled steels while retaining target mechanical properties, (ii) to obtain precise knowledge of the behavior of these steels in the various forming operations and (iii) to establish accurate user property data in the coated conditions. Three steel substrates (HSLA, DP, TRIP) with compositions providing yield strengths in the range of 400-620 MPa were selected. Only HSLA steel was found to be suitable for galnaizing and galvannealing in the hot rolled condition

Solvants eutectiques profonds - Vers des procédés plus durables

Deep eutectic solvents are a new class of solvents that appeared in the early 2000s. They are prepared by mixing two or more compounds and in general present a low environmental impact. In this article, we present the evolution of the still controversial definition of a deep eutectic solvent. Furthermore, the properties of these solvents are discussed and several potential applications are presented. Notably, their applications in electrochemical processes, in extraction and purification, as well as in reaction media or for the solubilization of gases or volatile organic compounds are considered. Their advantages as well as their limitations are examined.Les solvants eutectiques profonds sont une nouvelle classe de solvants apparue au début des années 2000. Ils sont obtenus par le mélange de deux ou de plusieurs composés et présentent en général un faible impact environnemental. Dans cet article, l’évolution de la définition d’un solvant eutectique profond est présentée, celle-ci n’étant toujours pas arrêtée précisément. Les propriétés de ces solvants sont exposées et leurs applications potentielles dans des procédés d’électrochimie, l’extraction et la purification, comme milieux réactionnels ou encore pour la solubilisation de gaz ou de composés organiques volatils, sont abordées. Leurs atouts mais également leurs faiblesses sont discutés

«Remédiation des COV par les cyclodextrines: de l’absorption à l’oxydation catalytique»

National audienc

Advanced methods of identification of sea-breeze and low-level jet events from near ground measurements with specific implication for energy production by offshore wind farms.

International audienc

Heterogeneous photo-Fenton oxidation with natural clays for phenol and tyrosol remediation

Due to their excellent properties, clays have been widely used in several applications, particularly in catalysis. In this paper, three clays were used as heterogeneous photo-Fenton catalysts for phenol and tyrosol oxidations. Particular attention was given to the effect of the main operating conditions on the process performance. A total conversion was obtained for both organic pollutants with studied catalysts in 20 minutes reaction. For phenol, a total organic carbon (TOC) conversion of 93% was obtained using sieved and calcined smectite clay. The TOC conversion was 60% for tyrosol with the same catalyst. Clays were characterized by chemical analysis, BET, XRD, TPR and SEM

Characterization of Cyclodextrin Cross-linked Polymers Used in Environmental Applications by Solid-state NMR Spectroscopy: a Historical Review

Cross-linked cyclodextrin polymers are attracting increasing interest not only from the scientific community but also from industry. These commercial polymers, discovered in the late 1960s, have applications in many fields, from pharmaceuticals to food processing, chromatography, cosmetics, membrane materials, and the environment. More recently, this class of functional polymers have been proposed as biosorbents to treat wastewater contaminated by conventional pollutants, such as metals, polycyclic aromatic hydrocarbons, phenols, and dyes, or emerging pollutants such as hormones, antibiotics, alkylphenols, and fluorine derivatives. However, although many results have been published, many questions remain not only on the chemical structure of the macromolecular networks of these polymers but also on the biosorption mechanisms involved in their use as biosorbents to treat pollutants. Solid-state NMR spectroscopy can help to answer these questions. This chapter aims to summarize and discuss the role of solid-state NMR spectroscopy in characterizing the structure of cross-linked cyclodextrin polymers and the interactions involved in biosorption using the state of the art and our own research results obtained over 25 years

Heterogeneous advanced photo-fenton oxidation of phenolic aqueous solutions over iron-containing SBA-15 catalyst

Iron-containing SBA15 catalysts have been prepared following different synthesisroutes, direct synthesis by adjusting pH at 3 and 6 and with post synthesis procedure. Activity and stability of these materials were assessed on the photo-Fenton degradation of phenolic aqueous solutions by H2O2 using near UV irradiation (254 nm) at room temperature and initial neutral pH. Their catalytic performance was mentioned in terms of phenol and total organic carbon (TOC) conversions. Several complementary techniques, including XRD, Nitrogen sorption isotherms, UV visible, were used to evaluate the final structural and textural properties of calcined Fe-SBA15 materials. These materials show a high activity and stability of iron species

Antibacterial activity of free or encapsulated selected phenylpropanoids against Escherichia coli and Staphylococcus epidermidis

International audienceAims Antibacterial activities of phenylpropenes (PPs) (eugenol, isoeugenol, estragole and trans-anethole) and hydroxycinnamic acids (HCAs) (p-coumaric, caffeic and ferulic acids) were assessed against Escherichia coli and Staphylococcus epidermidis. Effect of cyclodextrin and liposome encapsulation on the PPs activity was also evaluated. Methods and Results All PPs inhibited the bacterial growth in the hundred micromolar range, while HCAs did not, as determined by broth macrodilution. Anethole and estragole showed a higher efficiency than eugenol and isoeugenol, and E. coli was more susceptible than S. epidermidis. Hydroxypropyl-β-cyclodextrin/PP complexes and anethole-loaded Lipoid S100-liposomes were prepared by freeze-drying and ethanol injection respectively. Both formulations were substantially less active than free PPs. For instance, E. coli growth inhibition was about 14% for all HP-β-CD/PP complexes evaluated at MIC50 values of free PPs (P < 0·05), and about 12% for liposomal anethole evaluated at minimal bactericidal concentration value of free anethole (P < 0·05). Conclusions Hydrophobicity appears to be crucial for PPs antibacterial activity. Encapsulation in cyclodextrin and liposome seems to retain the PPs preventing their interaction with bacteria. Significance and Impact of the Study This study highlights the structural features of simple phenylpropanoids related to their antibacterial activity. The limitations of conventional encapsulation systems on the activity of PPs should be considered in future applications