Blin JL, Lesieur P, Stébé MJ. Nonionic fluorinated surfactant: investigation of phase diagram and preparation of ordered mesoporous materials.
LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004;
20:491-498. [PMID:
15743095 DOI:
10.1021/la035834k]
[Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The behavior of fluorinated surfactant F(CF2)8C2H4(OC2H4)9OH in water solution was investigated, and the preparation ofmesoporous molecular sieves was achieved. A direct micellar phase (L1) and a hexagonal (H1) liquid crystal were found. Small-angle X-ray scattering measurements proved that the hydrophobic chains are completely extended and that the cross sectional area remains constant in H1. At 80 degrees C, materials with a hexagonal array of their channel are prepared via a cooperative templating type mechanism in a wide range of surfactant concentrations (5-20 wt %). Decreasing the hydrothermal temperature leads to the formation ofwormhole-like structure. In this case the channel arrangement is no longer governed by the surfactant behavior but by the silica condensation and polymerization. An increase of the mean pore diameter with heating temperature is noted. This result is associated with changes of aggregation number with temperature. A comparison of the characteristics of the materials obtained with both hydrogenated and fluorinated surfactants is also made.
Collapse