[en] BODIPYs absorb in the visible region which is complementary to that of porphyrins and therefore can be suggested as promising antenna groups to improve the light-harvesting potential of porphyrins. A boron-dipyrromethene dye was combined at the 3-position with a Zn-porphyrin to afford a conjugate. The fluorescence of the conjugate was found to originate from the BODIPY moiety independently of the excitation wavelength due to an unique set of energy transfer rates between the BODIPY and Zn-porphyrin moieties. The fluorescence intensity was shown to be tunable over a wide range using the solvent properties. This feature makes the studied BODIPY-porphyrin conjugate a promising compound for the design of new photochromic devices.

[en] This study, originating mainly from a literature survey, gives the principal chemical and physical features of the tributyl-phosphate (TBP) agent diluted at 30 volumes per cent in dodecane. The mixture is a very commonly used extractant in nuclear fuel processing. In this paper, the main following points are reported: -) the components (TBP and diluents) -) the TBP-diluents systems (non-loaded), -) the TBP-diluents-water systems, -) TBP-diluents-water-nitric acid systems, and -) industrial solvents. (author)

No abstract available

No abstract available

[en] Full text of publication follows. To improve the recycling of nuclear fuel (as well as the reducing of the volume and the toxicity of ultimate waste), different actinide separations have been considered. Specific families of molecules were selected considering several criteria; among them the performance in terms of chemical affinity and selectivity towards the actinide target was important. The design and/or the optimization of new ligands could be improved with a deep understanding of actinides distribution and of the selectivity. N, N-dialkyl-amides RR'N-C(O)-R'' belong to a classical family of extractants which have been proposed some years ago to selectively separate uranium(VI) and plutonium(IV). The influence of the alkyl groups R, R' and R'' on the extraction and physico-chemical properties has already been discussed. But the relation between a macroscopic behavior of a solvent extraction system and the molecular contributions is difficult to obtain with high solute concentrations. In order to increase the knowledge in this field, a large number of investigations have been applied on the same extraction systems (3 reference dialkyl-amides): -) Thermodynamic data (free energy Δ_extG⁰, enthalpy Δ_extH⁰ and entropy Δ_extS⁰) were acquired by the classical Van't Hoff method and by direct calorimetry to provide the enthalpies of extraction and also specific heats; -) Dedicated methods like electro-spray ionization mass spectrometry analysis and X-ray diffraction on single crystals provide information about the stoichiometry of the extracted species; -) Spectroscopic investigations with UV-visible absorption, Fourier transform infrared and XAS experiments combined with theoretical calculations probed the actinide coordination in the inner sphere. The results obtained will be discussed to identify the origin of the different affinities between ligands and the difference of selectivity between cations. (authors)

[en] Solvent removal in many areas of scientific research, whether concentration of samples or complete drying has been considered as a major challenge during the solvent extraction processes. Personal solvent evaporator (PSE) is one of the advanced technologies system that have been developed for the solvent removal in various sample chemistries. This system consists of centrifugal vacuum concentrators and freeze driers capable of removing water and organic solvents. The techniques used in this system combines great performance, ease of use and compatibility with all commonly used solvents. This paper gives a brief overview of personal solvent evaporator for different solvent group and its application in scientific research such as natural product, analytical chemistry, medicinal chemistry and post purification sample handling. (author)

[en] The conceptual model for WIPP dissolved concentrations is a description of the complex natural and artificial chemical conditions expected to influence dissolved actinide concentrations in the repository. By a set of physical and chemical assumptions regarding chemical kinetics, sorption substrates, and waste-brine interactions, the system was simplified to be amenable to mathematical description. The analysis indicated that an equilibrium thermodynamic model for describing actinide solubilities in brines would be tractable and scientifically supportable. This paper summarizes the conceptualization and modeling approach and the computational results as used in the WIPP application for certification of compliance with relevant regulations for nuclear waste repositories. The WIPP site contains complex natural brines ranging from sea water to 10x more concentrated than sea water. Data bases for predicting solubility of Am(III) (as well as Pu(III) and Nd(III)), Th(IV), and Np(V) in these brines under potential repository conditions have been developed, focusing on chemical interactions with Na, K, Mg, Cl, SO₄, and CO₃ ions, and the organic acid anions acetate, citrate, EDTA, and oxalate. The laboratory and modeling effort augmented the Harvie et al. parameterization of the Pitzer activity coefficient model so that it could be applied to the actinides and oxidation states important to the WIPP system

[en] According to its merits about high curing speed and low emission of volatile organic compounds, UV curable inorganic-organic coating technology has been developed as an alternative for toxic and carcinogenic chromate-based treatments for years. It is consistently observed that ultra-thin films offer excellent corrosion protection as well as paint adhesion to metals. Based on the tetra-ethylorthosilicate(TEOS) and methacryloxypropyl trimethoxysilane(MPTMS), inorganic sol was synthesized and formed hybrid networks with UV curable acrylic monomer, 6-hexanediol diacrylate(HDDA), trimethylolpropane triacrylate(TMPTA), pentaer-ythritol triacrylate(PETA). Several methods were used to test their properties such as salt spray test, potentiodynamic measurement, tape peel test, etc. It was shown that anti-corrosive property and stability of storage were affected by the molecular ratios of inorganic and organic compounds. It was not only the stability of storage, but had a excellent anti-corrosive, paint adhesive, and anti-solvent properties in a final molar ratios of 0.6/0.04/0.86/0.005 (TEOS/MPTMS/Acetone/HNO3) and 0.08/0.106/0.081/0.02 (TMPTA/HDDA/PETA/photo initiator)

[en] The CEA has undertaken the development of the DIAMEX process as the first step in the strategy aiming at recovering minor actinides which could then be transmuted or separately conditioned. The scientific feasibility of this process was demonstrated during counter current hot tests operated in 1993. Then experimental works were conducted, on one hand to optimise the extractant formula, on the other hand to improve the flowsheet. Reference extractant and flowsheet were then chosen, respectively in 1995 and 1996. The next step, still in progress, is the demonstration of the DIAMEX technical feasibility (in 2002); this means that the flowsheet should include solvent regeneration treatments. In this aim, degradation studies were performed to quantify main degradation products, and identify those which could be disturbing in the process. This paper deals with experimental studies performed with intend to propose a regeneration treatment, included in the flowsheet, so that the solvent could be recycled. It comprises: - Quantification of the main degradation products issued from radiolysis or hydrolysis, which are methyl octyl amine (MOA) and carboxylic acids; - Effects of these products on extracting and hydrodynamics performances of the process; - Study of methods able to remove mainly disturbing degradation products. Acidic scrubbing, which are performed in the scrubbing and stripping sections of the DIAMEX process, should allow the quantitative removal of methyl octyl amine. Then basic scrubbings, which were more especially studied, should eliminate at least 80% of carboxylic acids, and part of the cations remaining in the solvent. (authors)

[en] Luminescence study of europium(III) ion was carried out in a phosphonium based bi-functionalised ionic liquid (FIL). The ionic liquid used in the study was trihexyltetradecylphosphonium bis(2,4,4- trimethylpentyl)phosphinate (Cyphos 104) while the diluent used was 1,4-diisopropylbenzene (DIPB). The aim of the paper is to understand the complexation of europium(III) in such type of ionic liquid system by luminescence spectroscopy study. The luminescence behaviour of europium(III) was ascertained as a function of various extraction parameters