Post-doctoral Researcher (Rhodia / CNRS)
 

Post-doctoral Researcher (Rhodia / CNRS)

"Local Dynamics in Polyamides, studied by Solid-State NMR" East Paris Institute of Chemistry and Materials Science (UMR 7182 CNRS / University of East Paris - Créteil), Thiais, France A 12 months postdoctoral position is opened in the framework of a collaboration between the CNRS/Rhodia joint Research Lab "Laboratoire Polymères et Matériaux Avancés" (LPMA, UMR 5268), Lyon, France, and the CNRS/University of East Paris - Créteil joint Research Lab "East Paris Institute of Chemistry and Materials Science" (ICMPE, UMR 7182), Thiais, France. The postdoctoral researcher will develop his/her research activities at ICMPE, Thiais, in the department "Complex Polymer Systems" and will be co-supervised by Cédric Lorthioir (ICMPE) and Paul Sotta (LPMA). Rhodia is a global specialty chemicals manufacturer with 5 multidisciplinary Research & Development Centers worldwide. Lyon is the main Rhodia R&D Center for Europe. CNRS is the main governmental research organization in France, involved in all scientific fields. Partially polar polymers are very sensitive to water. For example a dry semi-crystalline polymer like polyamide (PA) can absorb up to 12 wt% water in saturated humid atmosphere (Relative Humidity = RH 100). The water content drastically affects the glass transition temperature, which may be shifted from 80°C in the dry state down to -10°C in the humid state, and therefore the mechanical and other properties. The purpose of this work is to combine advanced Solid-State NMR approaches to investigate the molecular dynamics in polyamides. Selective Solid-State NMR experiments, performed as a function of temperature, will allow identifying the specific types of motions corresponding to the various relaxation processes observed in these materials, in the amorphous phase. The mobility and mobility gradients in the amorphous phase located in the vicinity of the crystallites will be characterized by selective excitation of the crystalline signal combined with 1H spin diffusion. Model polyamide materials with a variable, controlled crystallinity will be considered. The dynamics will be studied both in the dry state and in the presence of various amounts of water. These experiments will clarify the mechanisms by which water plasticizes polyamide. The position is to start any time. It is opened to an experimental physicist/physico-chemist, with a PhD thesis in the field of polymer physics or chemical physics. An experience in Solid-State NMR, if not mandatory, will be highly appreciated. Gross salary is about 2000 Euros/month. To apply, please send an application letter together with a detailed CV and contact details of two academic referees to either of the following contact persons: Paul Sotta Laboratoire Polymères et Matériaux Avancés CRTL 85, rue des Frères Perret 69192 Saint-Fons Cedex, France Tel: +33 (0)4 72 89 64 66 E-mail: paul.sotta-exterieur@eu.rhodia.com Cédric Lorthioir Institut de Chimie et des Matériaux Paris-Est Equipe ‘Systèmes Polymères Complexes‘ 2-8, rue Henri Dunant 94320 Thiais, France Tel: +33 (0)1 49 78 13 08 E-mail: lorthioir@icmpe.cnrs.fr

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