Measurement of the optical parameters of the Virgo interferometer

The Virgo interferometer, aimed at detecting gravitational waves, is now in a commissioning phase. Measurements of its optical properties are needed for the understanding of the instrument. We present the techniques developed for the measurement of the optical parameters of Virgo. These parameters are compared with the Virgo specifications.     

Synthesis of pH-sensitive micelles from linseed oil using atom transfer radical polymerisation (ATRP)

This paper reports the synthesis of an amphiphilic copolymer from linseed oils and its successive auto-association in water into pH-sensitive micelles. An original ATRP lipoinitiator is first designed from linseed oil in two steps. tert-butyl acrylate (tBA) polymerization is consequently initiated from this original initiator and amphiphilic copolymers are obtained after subsequent acidolysis of the PtBA block into poly(acrylic acid) (PAA). The ability of a lipid-b-PAA copolymer to auto-associate in water is finally investigated through different techniques (Fluorescence, Surface Tension, QELS). This copolymer forms well-defined micelles in acidic media with a low critical micellar concentration (cmc) of 7.6 mg L^?1 and dissociates when the pH is raised above 7.     

Poly(butylene succinate)/layered double hydroxide bionanocomposites: Relationships between chemical structure of LDH anion,delamination strategy,and final properties

A series of poly(butylene succinate) (PBS) containing organo‐modified layered double hydroxide (LDH) are prepared by melt compounding and by in situ polymerization of succinic ester and 1,4‐butanediol. Various LDHs intercalated with renewable organic anions are used. More specifically, lauryl sulfate, stearate, succinate, adipate, sebacate, citrate, and ricinoleate ions are used as LDHs organo‐modifiers. The thermal, rheological, and dynamic mechanical properties of the samples are investigated. The results reveal a general mechanical reinforcement imparted by the clays. Significant changes are observed for the in situ polymerized nanocomposites, especially for LDH stearate which improves the properties of PBS nanostructure, whereas very few differences are observed for the other samples. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1931–1940, 2013     

Low degree of functionalization of Single-Walled Carbon Nanotubes probed by highly sensitive characterization techniques

Single-Walled Carbon Nanotubes (SWCNTs) were functionalized using a one-step radical addition procedure leading to a desired low functionalization degree. Based on well chosen techniques, the characterization of the functionalized samples allows having a good feedback on the functionalization process. We were able to determine the functionalization level and the nature of the bonds between the SWCNT surface and the functional groups. By means of a TGA–mass spectrometry coupling technique, the mechanisms of detachment upon heating were used to determine the nature of the grafted functional groups. In addition to the expected groups, unexpected groups were covalently grafted on the sample surface. Based on inert gas adsorption properties, we show that the functional groups are unambiguously grafted on the SWCNT sidewalls.     

Importance of sample intraparticle diffusivity in investigations of the mass transfer mechanism in liquid chromatography

The effective diffusivity of a nonretained (thiourea) and of a strongly retained (phenol) compounds were measured with the peak parking method in two different columns (both 150 × 4.6 mm) packed with two types of porous particles having different mesopore sizes [5 μm Jupiter‐C₁₈, 320 Å and Luna(2)‐C₁₈, 100 Å]. The eluent was a methanol–water mixture (10/90 v/v) and the temperature 294 K. The effective diffusivity data acquired were used to determine the intraparticle diffusivity, D_p, based on two different diffusion models. The first one assumes that the diffusion fluxes across the particles and in the interparticle volume are additive (parallel diffusion model). The second model was rigorously derived on the basis of the effective medium theory of diffusion (diffusion model) in a binary composite medium (particles + interparticle volume). In both models, it was assumed that the rate of equilibrium between the liquid and the solid phases was infinitely faster than the rate of axial diffusion along the column at zero flow rate. Both models provide physically meaningful intraparticle diffusivity coefficients that take into account the average mesopore size of the particles, their specific surface area, and the retention factor of the analyte. Although the actual effective intraparticle diffusivity remains unknown, these result confirm that the mass transfer resistance due to diffusion through the porous particles has almost negligible effects in reversed phase liquid chromatography due to the importance of surface diffusion. Combining the results of the peak parking method with the h data measured at high linear velocities allows the unambiguous measurement of the film mass transfer and the surface diffusion coefficients. © 2010 American Institute of Chemical Engineers AIChE J, 2011     

Characterization of screen printed carbon counter electrodes for Co(II)/(III) mediated photoelectrochemical cells

A screen printed carbon electrode associated with Tris(4,4′-di-tert-butyl-2,2′-bipyridine)Cobalt(II) as redox mediator was investigated as possible alternative to the volatile and corrosive iodide/triodide system in dye sensitized solar cells (DSSCs). We report here a first study on the screen printing technology for the manufacturing of an advanced and stable carbon cathode for dye sensitized solar cell. The electrode surface was characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) while the electrochemical response towards the cobalt complex was evaluated by using cyclic voltammetry. Photocurrent-voltage characteristics of DSSCs based on the new cathode/Cobalt complex system were 30% lower than those recorded with Pt/iodide.     

Ternary blends for polymer bulk heterojunction solar cells

The objective of this mini‐review is to outline current major ternary blends used in the active layer of polymer bulk heterojunction photovoltaic solar cells and to give an insight into the direction of the field. The use of a third‐component material in polymer ? fullerene blends is described in two sections. On the one hand, the first family of solid state additives enables us to enlarge photon collection by expanding the action spectra of the solar cells. The second section deals with materials used to engineer bulk heterojunction morphology at the nanoscale. The different approaches explored for many of the ternary blend systems suggest the great potential of such mixtures to significantly improve the optoelectronic properties of solar cells on a long‐term basis. © 2013 Society of Chemical Industry     

Synthesis of polymer–silica hybrid polyHIPEs by double in situ polymerization of concentrated water in oil emulsion

Highly porous monoliths from polymerized high internal phase emulsions (polyHIPEs) are proposed for a number of applications including liquid absorbents, biocatalysis, tissue engineering, bioseparation etc. To overcome some limitations of fully organic polyHIPEs hybrid organic–inorganic templated porous polymers are particular attractive. Here we present a straightforward protocol towards hybrid polyHIPEs by combining fast photo polymerization of the organic HIPE with in-situ polycondensation of tetraethylorthosilicate (TEOS). While under acidic conditions TEOS polymerization leads to a more bicontinous structure, true double-layered morphologies were obtained under basic conditions as evident from SEM imaging, mercury intrusion porosimetry and nitrogen physisorption measurements. Moreover, chemical amine functionalization of the silica network surface of the hybrid polyHIPEs was demonstrated using a silane coupling agent and subsequent visualization by reaction with fluorescein isothiocyanate (FITC).     

Biomarkers of inflammation,metabolism, and oxidative stress in blood,liver, and milk reveal a better immunometabolic status in peripartal cows supplemented with Smartamine M or MetaSmart

The peripartal dairy cow experiences a state of reduced liver function coupled with increased inflammation and oxidative stress. This study evaluated the effect of supplementing basal diets with rumen-protected Met in the form of MetaSmart (MS) or Smartamine M (SM) (both from Adisseo Inc., Antony, France) during the peripartal period on blood and hepatic biomarkers of liver function, inflammation, and oxidative stress. Thirty-seven multiparous Holstein cows were fed the same basal diet from −50 to −21 d relative to expected calving [1.24 Mcal/kg of dry matter (DM); no Met supplementation]. From −21 d to calving, the cows received diets (1.54 Mcal/kg of DM) with no added Met (control, CON; n = 13), CON plus MS (n = 11), or CON plus SM (n = 13). From calving through 30 d in milk (DIM), the cows received the same postpartal diet (1.75 Mcal/kg of DM; CON), or CON plus MS or CON plus SM. Liver and blood samples were harvested at various time points from −21 to 21 d relative to calving. Preplanned contrasts of CON versus SM + MS during prepartum (−21 and −10 d before calving) and postpartum (7, 14, and 21 d after calving) responses were evaluated. Cows fed MS or SM compared with CON had lower overall concentrations of plasma ceruloplasmin and serum amyloid A (SAA). Compared with CON, Met-supplemented cows had greater overall plasma oxygen radical absorbance capacity. Liver concentrations of glutathione and carnitine also were greater overall with Met supplementation. Milk choline and liver phosphatidylcholine were lower overall in cows fed Met compared with controls. Liver tissue choline concentrations did not differ. Data indicate that supplemental Met enhanced de novo glutathione and carnitine synthesis in liver and, thus, increased antioxidant and β-oxidation capacity. The greater decrease of IL-6 after calving coupled with lower ceruloplasmin and SAA in Met-supplemented cows indicated a reduction in proinflammatory signaling within liver. The lower hepatic phosphatidylcholine in Met-supplemented cows might have been associated with greater assembly or export of very low density lipoproteins. Overall, biomarker analyses in blood and tissue indicate that the beneficial effect of feeding SM and MS on postpartal cow performance is due in part to a better immunometabolic status.