Search results for "Behenic acid"
showing 7 items of 7 documents
Monolayers of Amphiphilic Molecules
1992
There are good reasons why the organizers have placed this lecture at the beginning of a conference on the multip1e aspects of membranes. In many respects the monolayer may be considered half of a membrane and it obviously is the most simple and best-defined model system. Yet we will show that the system is more complex than many have anticipated. On the other hand, there are many general features which can be discussed without looking into chemical details.
Behenic Acid as a Structural Model for Fatty Acid Monolayers at the Air/Water Interface: An X-Ray Diffraction Study
1992
We present an X-ray diffraction study of behenic (docosanoic) acid films at the air/water interface. Analysis of the rod profiles parallel and perpendicular to the surface provides detailed information on the unit cells of five different phases.
Langmuir−Blodgett Films of a Mo-Blue Nanoring [Mo142O429H10(H2O)49(CH3CO2)5(CH3CH2CO2)]30- (Mo142) by the Semiamphiphilic Method
2007
Langmuir monolayers and LB films of the ring-shaped mixed-valence polyoxomolybdate [Mo142O429H10(H2O)49(CH3CO2)5(CH3CH2CO2)]30- (Mo142) dissolved in the aqueous subphase have been successfully fabricated by using the adsorption properties of a DODA monolayer. Infrared and ultraviolet−visible spectroscopy of the LB films indicates that Mo142 and DODA molecules are incorporated within these LB films. X-ray reflectivity experiments indicate that the LB films exhibit a well-defined lamellar structure formed by bilayers of DODA molecules alternating with monolayers of Mo142. Using behenic acid-modified hydrophobic quartz substrate is critical for the formation of the well-defined lamellar struct…
Structural Relationships between Floating and Deposited Monolayers of Docosanoic Acid
1991
Floating docosanoic acid (behenic acid) monolayers in the SmI and SmH phase were deposited with the Langmuir-Blodgett technique onto thin polymethylmethacrylate (PMMA) and Formvar substrates and investigated by electron diffraction. The molecular packing of the monolayers on the substrates vary from those on the water surface and are different for different substrates. On PMMA four phases (H, SmB, SmI, SmL) have been identified, depending on the deposition conditions. While SmB and SmI are known for docosanoic acid on the water surface, H and SmL have only been unequivocally observed in other substances or on other subphases. The monolayer structure on Formvar was identical under all deposi…
Ellipsometric studies of behenic acid at the air-water interface
1991
The rich phase behaviour of monolayers of behenic acid (=docosanoic acid) has been analyzed by null ellipsometry in isothermic and isobaric measurements. By using structural data known from x-ray measurements the anisotropy and refractive indices in the vicinity of the S-CS phase transition have been calculated with a minimum of model assumptions. The calculated values are: nsx=1.47. ncsx=1.48. nsz=1.54. ncsz=1.55. and anisotropy γ=nx/nz ≈0.95. It is also shown that ellipsometry is a very sensitive and convenient method of detecting phase transitions. Its value for quantifying the roughness of the monolayer in the close vicinity of phase transitions due to thickness and density fluctuations…
Langmuir-Blodgett Films of Magnetic Clusters
1999
Abstract The mixed-valence manganese clusters [Mn12O12(carboxylato)16] have been organized in a multilayer architecture. Indeed, well-defined Langmuir-Blodgett (LB) films of the acetate and the benzoate Mn12 clusters can be obtained using behenic acid as organic matrix. Here, we report the magnetic properties of these multilayers, which present a marked hysteresis at 2 K.
Langmuir–Blodgett films based on inorganic molecular complexes with magnetic or optical properties
2005
Langmuir and Langmuir–Blodgett (LB) films of a great variety of molecular metal complexes with interesting magnetic or optical properties have been prepared in the last few years. Some of the results obtained by our group and others are summarized in this article. (i) LB films of polyoxometalates (POM) were first prepared taking advantage of the adsorption properties of these cluster anions along a positively charged monolayer of an organic surfactant spread in water. A correct choice of the POM allowed the preparation of LB films with magnetic, electrochromic, or luminescent properties. Besides this semiamphiphilic method, two new methods to prepare LB films of POMs have been developed by …