Abstract
Binary mixtures of the poly(oxyethylene) surfactant C12EO2 and water have been investigated using optical microscopy and time-resolved X-ray diffraction during temperature scans. At concentrations in the range from 48 to 70 wt % of surfactant a thermal sequence from lamellar Lα to cubic Ia3d to cubic Pn3m to L2 was found upon heating. The geometrical parameters of the phases such as thickness of the hydrocarbon core of the lamellar phase and length and diameter of the rods forming the cubic structures were calculated for such conditions. In the lamellar Lα phase the surface area per molecule and the thickness of the hydrocarbon core showed little sensitivity to concentration. The thickness of the ethoxy groups was estimated to 1 nm. At high concentrations and temperatures near the cloud point, equilibrium conditions are difficult to reach, leading to the formation of cubic phases with apparently the same structure but different thermal behavior. One is insensitive to temperature changes while the other shrinks upon heating. The transition between the Ia3d and Pn3m cubic phases has the characteristics of a Bonnet transformation.
Keywords
Lamellar structureMaterials sciencePulmonary surfactantPhase (matter)RodHydrocarbonDiffractionCrystallographyLiquid crystalCore (optical fiber)Analytical Chemistry (journal)ThermodynamicsChemistryOpticsComposite materialChromatographyOrganic chemistry
Related Publications
Surfactant Control of Phases in the Synthesis of Mesoporous Silica-Based Materials
The low-temperature formation of liquid-crystal-like arrays made up of molecular complexes formed between molecular inorganic species and amphiphilic organic molecules is a conv...
Thermal Stability of Lithium Nickel Oxide Derivatives. Part II: Li<i><sub>x</sub></i>Ni<sub>0.70</sub>Co<sub>0.15</sub>Al<sub>0.15</sub>O<sub>2</sub> and Li<i><sub>x</sub></i>Ni<sub>0.90</sub>Mn<sub>0.10</sub>O<sub>2</sub> (<i>x</i> = 0.50 and 0.30). Comparison with Li<i><sub>x</sub></i>Ni<sub>1.02</sub>O<sub>2</sub> and Li<i><sub>x</sub></i>Ni<sub>0.89</sub>Al<sub>0.16</sub>O<sub>2</sub>
he thermal degradation mechanism of LixNi0.70Co0.15Al0.15O2 and LixNi0.90Mn0.10O2 (x = 0.50 and 0.30) was studied by thermal gravimetric analysis coupled with mass spectrometry....
Cooperative Formation of Inorganic-Organic Interfaces in the Synthesis of Silicate Mesostructures
A model is presented to explain the formation and morphologies of surfactant-silicate mesostructures. Three processes are identified: multidentate binding of silicate oligomers ...
Inversion Symmetry Breaking by Oxygen Octahedral Rotations in the Ruddlesden-Popper<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>Na</mml:mi><mml:mi>R</mml:mi><mml:msub><mml:mrow><mml:mi>TiO</mml:mi></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>Family
Rotations of oxygen octahedra are ubiquitous, but they cannot break inversion symmetry in simple perovskites. However, in a layered oxide structure, this is possible, as we demo...
Nonionic Triblock and Star Diblock Copolymer and Oligomeric Surfactant Syntheses of Highly Ordered, Hydrothermally Stable, Mesoporous Silica Structures
A family of highly ordered mesoporous (20−300 Å) silica structures have been synthesized by the use of commercially available nonionic alkyl poly(ethylene oxide) (PEO) oligomeri...
Publication Info
- Year
- 1997
- Type
- article
- Volume
- 101
- Issue
- 5
- Pages
- 732-739
- Citations
- 50
- Access
- Closed
External Links
Social Impact
Altmetric
PlumX Metrics
Social media, news, blog, policy document mentions
Citation Metrics
50
OpenAlex
Cite This
Sérgio S. Funari,
Gert Rapp
(1997).
X-ray Studies on the C<sub>12</sub>EO<sub>2</sub>/Water System.
The Journal of Physical Chemistry B
, 101
(5)
, 732-739.
https://doi.org/10.1021/jp9629250
Identifiers
- DOI
- 10.1021/jp9629250