Procédé de polymérisation en solution : passage du batch au continu

National audienc

Simple and Straightforward Synthesis of Porous Ionosilica for Efficient Chromate Adsorption

International audienceWe report a very simple synthesis strategy for the formation of moderately porous ionosilica materials containing ammonium groups. We synthesized an ionosilica xerogel and an ionosilica aerogel, either via conventional or super-critical work-up. The synthesis scheme of both precursor and ionosilica materials could easily be up-scaled to a 100 g scale. All syntheses and work-up procedures are sustainable as no additional agent and very low quantities of solvents were used, and no additional purifications steps were necessary. Although both materials show excellent anion exchange properties for chromate adsorption, noticeable differences were found regarding the thermodynamics of the exchange process. We attribute these differences to different surface chemistries of the materials, induced by the different work-up procedures. Due to the easy availability of high quantities of material, ionosilicas can be implemented as functional ion exchange materials in larger scale processes, thus opening new fields of applications

Application of Raman Spectroscopy to Characterization of Residence Time Distribution and Online Monitoring of a Pilot-Scale Tubular Reactor for Acrylic Acid Solution Polymerization

International audienceA pilot-scale tubular reactor containing static mixers is equipped with several Raman probes in order to perform online monitoring of radical copolymerization of acrylic acid in aqueous solution. This setup allows determination of residence time distribution while polymerization reaction occurs, using sodium nitrate as a tracer. These results prove that the use of convenient static mixers allows obtaining a nearly perfect plug-flow reactor in all explored conditions (reactive and nonreactive medium, between 0.001 and 1 Pa s viscosity). Furthermore, the dynamics of the pilot-scale reactor is characterized. Experimental transient and steady-state values are compared to predictions based both on residence time distribution and model of polymerization kinetics. The applicability of Raman spectroscopy to online monitoring of pilot-scale reactors is demonstrated

Intensification of a copolymerization process: viscosity measurement and access to conversion

International audienc

Genetic Variants of GPER/GPR30, a Novel Estrogen-Related G Protein Receptor, Are Associated with Human Seminoma

Testicular germ cell tumors (TGCTs) are the most common solid cancers in young men, with an increasing incidence over several years. However, their pathogenesis remains a matter of debate. Some epidemiological data suggest the involvement of both environmental and genetic factors. We reported two distinct effects of estrogens and/or xeno-estrogens on in vitro human seminoma-derived cells proliferation: (1) an antiproliferative effect via a classical estrogen receptor beta-dependent pathway, and (2) a promotive effect via a non-classical membrane G-protein-coupled receptor, GPR30/GPER, which is only overexpressed in seminomas, the most common TGCT. In order to explain this overexpression, we investigated the possible association of polymorphisms in the GPER gene by using allele-specific tetra-primer polymerase chain reaction performed on tissue samples from 150 paraffin-embedded TGCT specimens (131 seminomas, 19 non seminomas). Compared to control population, loss of homozygous ancestral genotype GG in two polymorphisms located in the promoter region of GPER (rs3808350 and rs3808351) was more frequent in seminomas but not in non-seminomas (respectively, OR = 1.960 (1.172–3.277) and 7.000 (2.747–17.840); p < 0.01). These polymorphisms may explain GPER overexpression and represent a genetic factor of susceptibility supporting the contribution of environmental GPER ligands in testicular carcinogenesis