Nonionic Fluorinated Surfactant Removal from Mesoporous Film Using sc-CO.

Surfactant templated silica thin films were self-assembled on solid substrates by dip-coating using a partially fluorinated surfactant R(EO) as the liquid crystal template. The aim was 2-fold: first we checked which composition in the phase diagram was corresponding to a 2D rectangular highly ordered crystalline phase and second we exposed the films to sc-CO to foster the removal of the surfactant. The films were characterized by in situ X-ray reflectivity (XRR) and grazing incidence small angle X-ray scattering (GISAXS) under CO pressure from 0 to 100 bar at 34 °C.

Investigation of mixed fluorinated and triblock copolymer liquid crystals: imprint for mesostructured bimodal silica.

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.

A sensitive spectrofluorimetric method for the quantification of melamine residue in milk powder using the Mannich reaction in aqueous solutions.

The objective of this study was to develop a spectrofluorimetric method for the quantitative determination of melamine. The method was based on the complexation of melamine with a mixture of formaldehyde and chemicals including a ketone group, as described by the Mannich reaction. The complex was determined by spectrofluorimetric measurement as it is characterized by specific spectroscopic properties that are related to the chromophore of the ketone compounds.

Remediation of 4-nonylphenol in aqueous solution by using free radicals generated by the oxidative reactions.

Introduction: This study relates to use of zerovalent iron to generate hydroxyl free radicals and undergo subsequent oxidation to destroy 4-nonylphenol (NP) by mild process in aqueous solution and activation of oxygen gas (O2) at room temperature. This technology is based on a novel oxidative mechanism mediated by zerovalent iron rather than commonly used reduction mechanism.

Materials And Methods: A laboratory scale device consisting of a 250 ml pyrex serum vials fixed to a Vortex agitator was used.