title: Investigation of mixed fluorinated and triblock copolymer liquid crystals: imprint for mesostructured bimodal silica.
abstract: Due to the difference in «mutual phobicity» between fluorocarbon and hydrocarbon chains, mixtures of fluorinated and hydrogenated surfactants are excellent candidates to design bimodal systems having two types of mesopores. In literature, only a few papers deal with these bimodal systems. Here hexagonal liquid crystal mixtures of the polyoxyethylene fluoroalkyl ether [R(F)8(EO)9] and the Pluronic [P123] have been used to template this kind of mesostructure through the liquid crystal mechanism, which is barely considered. After the detailed investigation of the R(F)8(EO)9/P123/water liquid crystal domain, materials have been synthesized and characterized by small angle X-ray scattering, transmission electron microscopy and nitrogen adsorption-desorption analysis. Our results show that this system provides two separate pore sizes in the materials over the mesoporous range. The ratio between the small mesopores and the large ones depends on the proportion between the porogens in the mixture. Nonetheless, we also outline that a minimum quantity of silica is required to recover the two hexagonal networks.
authors: Université de Lorraine/CNRS, SRSMC, UMR7565, F-54506 Vandoeuvre-lès-Nancy cedex, France.
authors: Karine
authors: K
authors: Assaker
authors: Université de Lorraine/CNRS, SRSMC, UMR7565, F-54506 Vandoeuvre-lès-Nancy cedex, France.
authors: Issam
authors: I
authors: Naboulsi
authors: Université de Lorraine/CNRS, SRSMC, UMR7565, F-54506 Vandoeuvre-lès-Nancy cedex, France.
authors: Marie-José
authors: MJ
authors: Stébé
authors: Université de Lorraine/CNRS, SRSMC, UMR7565, F-54506 Vandoeuvre-lès-Nancy cedex, France.
authors: Mélanie
authors: M
authors: Emo
authors: Université de Lorraine/CNRS, SRSMC, UMR7565, F-54506 Vandoeuvre-lès-Nancy cedex, France. Electronic address: Jean-Luc.Blin@univ-lorraine.fr.
authors: Jean-Luc
authors: JL
authors: Blin
mesh_terms: D000327:Adsorption; D004986:Ether / Q000737:chemistry; D054879:Halogenation; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry*; D050866:Liquid Crystals / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D054802:Molecular Imprinting; D011060:Poloxalene / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D016062:Porosity; D053838:Scattering, Small Angle; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D006845:Hydrocarbons, Fluorinated; D011108:Polymers; D013501:Surface-Active Agents; D004986:Ether; C464484:pluronic block copolymer P123; D011092:Polyethylene Glycols; D012822:Silicon Dioxide; D011060:Poloxalene
keywords: Bimodality; Liquid crystals; Mesoporous materials; Silica; Surfactant mixture