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Offre de thèse_Structure - optical properties relationship of colored polymer / liquid-crystal composite materials for applications to smart windows

PhD Offer 2021 – CIFRE Saint-Gobain

Structure - optical properties relationship of colored polymer / liquid-crystal composite materials for applications to smart windows

 

Context. Liquid crystals (LCs) are viscoelastic soft materials known for their most famous use in displays (LCDs). LCs can also be processed into various composite films with new adjustable privacy, dimming and thermal insulation properties that improve visual and thermal comfort of inhabitants. For instance, Saint-Gobain owns SGG Priva-Lite®, a smart window made of micrometric LC droplets dispersed within a polymer matrix that switches from a hiding state to a transparent one when powered.

 

Research topic.

The laboratory Surface du Verre et Interfaces (SVI), a Saint-Gobain/CNRS joint research unit located in Aubervilliers, has recently developed a new promising approach for the realization of smart windows that is based on the organization and optical properties of topological defects within colored composite matrices comprised of LCs and polymer networks. Meanwhile, two academic teams at Laboratory Physique des Systèmes Complexes (PSC) in Amiens and Laboratory Physiques des Solides (LPS) in Orsay have been studying the physical properties of a new type of LC phase, called « twist-bend nematic » (NTB), which exhibit specific topological defects of potential interest for this kind of application as well.

The PhD work will then consist in a detailed study of the morphologies of polymer networks formed in different LC, including NTB phases decorated with various kinds of topological defects, and of their influence on the electro-optical properties of the composite materials. The tasks will involve formulation of various LC/polymer composites, and determination of their structural, textural, and electro-optical properties as a function of the materials’ chemical composition and polymerization conditions, and nature of topological defects. Experimental characterizations will include x-ray and light scattering, differential scanning calorimetry, polarized light and confocal Raman microscopies, and dielectric and electro-optic measurements of the composites submitted to an electric field.

 

Candidate profile

Experimentalist with a broad condensed-matter physico-chemistry background and a strong taste for team work. The PhD student will benefit from both academic and industrial environments as the work will be performed at PSC, LPS, and SVI, the latter laboratory being located within Saint-Gobain Research Paris, one of the largest transverse R&D centers of the group.

 

Applications including a CV and cover letter must be sent to:

Ms. Claire Meyer (PSC), Associate Professor at Univ. de Picardie Jules Verne: claire.meyer@u-picardie.fr;

Mr. Patrick Davidson (LPS), CNRS Research Director: patrick.davidson@universite-paris-saclay.fr ;

Mr. Frédéric Mondiot (SVI), Saint-Gobain Researcher: Frederic.Mondiot@saint-gobain.com.

Ms. Maria Malheiro Reymao: Maria.MalheiroReymao@saint-gobain.com