Phase behavior and preparation of mesoporous silica in aqueous mixtures of fluorinated surfactant and hydrophobic fluorinated polymer

• Published in: Journal of colloid and interface science 2006-07, Vol.299 (1), p.297-304
• Main Authors: Sharma, Suraj Chandra, Kunieda, Hironobu, Esquena, Jordi, Rodríguez Abreu, Carlos
• Format: Article
• Language: English
• Subjects: Chemistry; Colloidal state and disperse state; Exact sciences and technology; Fluorinated surfactant; General and physical chemistry; Liquid crystals; Mesoporous silica; Phase behavior; Polymeric oil; Porous materials; Rheology
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2006.01.040

The phase behavior and formation of self-assemblies in the ternary water/fluorinated surfactant (C 8F 17EO 10)/hydrophobic fluorinated polymer (C 3F 6O) n COOH system and the application of those assemblies in the preparation of mesostructured silica have been investigated by means of phase study, small angle X-ray scattering, and rheology. Hexagonal (H 1), bicontinuous cubic (V 1) with Ia3d symmetry, and polymer rich lamellar ( L α ′ ) are observed in the ternary diagram. C 8F 17EO 10 molecules are dissolved in polymer rich aggregates, whereas (C 3F 6O) n COOH molecules are practically insoluble in the surfactant lamellar phase due to packing restrictions. Hence, two types of lamellar phases exist: one with surfactant rich ( L α ) and the other with polymer rich ( L α ′ ) in the water/C 8F 17EO 10/(C 3F 6O) n COOH system. As suggested by rheological measurements, worm-like micelles are present in C 8F 17EO 10 aqueous solutions but a rod-sphere transition takes place by solubilization of (C 3F 6O) n COOH. C 8F 17EO 10 acts as a structure directing agent for the preparation of hexagonal mesoporous silica by the precipitation method. The addition of (C 3F 6O) n COOH induces the formation of larger but disordered pores.