Aggregation of semifluorinated alkanes in cyclic organic solvents: A SAXS study

Abstract

Semifluorinated alkanes (SFA) are diblock molecules able to self-assemble in various organic media due to their fluorophilic/fluorophobic interactions. Such mixtures accordingly represent a model system for the further elaboration of soft-templated inorganic materials in totally anhydrous media. The aggregation behavior of four SFA species has been studied in two different organic and cyclic solvents in function of temperature by small angle X-ray scattering (SAXS). As long as the SFA-solvent mixtures remain in the liquid state, SAXS patterns reveal an aggregation behavior dependent on temperature and concentration, and on the internal structure of the SFA. We identify the relevant parameters governing the aggregation of these molecules based on the simulation of SAXS data versus temperature.

Highly crystalline silicon carbide of controlled mesoporosity

“…This so-called "soft-templating" approach has thus been used to produce nanoporous SiC, involving molecular or polymeric templating agents, which can be e.g. semifluorinated alkanes [11,12] in the first case, or block copolymers [13][14][15][16][17][18][19][20] in the second case. Concerning approaches involving block-copolymers, it has been reported the synthesis of nanostructured SiC with a grain size of approximately 30 nm by self-assembly of polyvinylsilazane-block-polystyrene (PVSZ-b-PS) block copolymers and SiC precursor followed by pyrolysis at 800 °C to form nanoporous SiC [16].…”