Monolayers and Multilayers of Uranyl Arachidate. 1. Study of the Interaction of Dissolved Uranyl Ions with Arachidic Acid Langmuir Monolayers

Penacorada, Florencio; Reiche, J.; Katholy, S.; Brehmer, L.; Rodríguez-Mendez, M. L.

doi:10.1021/la00010a065

Cited by 23 publications

(18 citation statements)

References 2 publications

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“…The isotherms recorded on a 200 × 10 −3 m calcium nitrate subphase show the same trend, but the collapse of the film already occurs at a surface pressure of 45 mN m −1 which is almost 20 mN m −1 lower compared to the lower concentrations. Several studies have shown that bivalent metal ions such as Ca 2+ have the ability to stabilize the amphiphile monolayer due to the interaction of the metal ions with two carboxylic groups . In this study, we do not observe this type of monolayer stabilization.…”

Section: Resultscontrasting

confidence: 79%

A Dendritic Amphiphile for Efficient Control of Biomimetic Calcium Phosphate Mineralization

Hentrich

Taabache

Brezesinski

et al. 2017

Macromolecular Bioscience

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The phase behavior of a dendritic amphiphile containing a Newkome-type dendron as the hydrophilic moiety and a cholesterol unit as the hydrophobic segment is investigated at the air-liquid interface. The amphiphile forms stable monomolecular films at the air-liquid interface on different subphases. Furthermore, the mineralization of calcium phosphate beneath the monolayer at different calcium and phosphate concentrations versus mineralization time shows that at low calcium and phosphate concentrations needles form, whereas flakes and spheres dominate at higher concentrations. Energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and electron diffraction confirm the formation of calcium phosphate. High-resolution transmission electron microscopy and electron diffraction confirm the predominant formation of octacalcium phosphate and hydroxyapatite. The data also indicate that the final products form via a complex multistep reaction, including an association step, where nano-needles aggregate into larger flake-like objects.

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Section: Resultscontrasting

confidence: 79%

A Dendritic Amphiphile for Efficient Control of Biomimetic Calcium Phosphate Mineralization

Hentrich

Taabache

Brezesinski

et al. 2017

Macromolecular Bioscience

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“…For simple fatty acids, this finding even allowed the shape of the surface potential curves to be quantitatively explained . In the case of YbPc 2 monolayers, the critical area can be related to the coming together of domains known to exist even at very large areas per molecule, which has been shown to occur for a number of compounds through Brewster angle microscopy . This explains the observed nonzero surface potentials for larger volumes of spreading solution.…”

Section: Resultsmentioning

confidence: 83%

Surface Pressure and Surface Potential Isotherms of Ytterbium Bisphthalocyanine Langmuir Monolayers

et al. 1999

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A systematic study is reported on the monolayer characteristics of ytterbium bisphthalocyanine (YbPc2) at the air−water interface, using surface pressure and surface potential isotherms. The influence of various experimental parameters was analyzed, including compression speed, spreading volume, position of the pressure sensor, and subphase temperature. The area per molecule decreased with increasing spreading volumes. Interestingly, the position of the Wilhelmy plate affected the pressure−area isotherms, which does not occur for traditional aliphatic compounds. No significant influence from the subphase temperature was detected. Upon varying the compression speed, the surface potential curve and the collapse pressure were affected, even though the area per molecule remained practically the same. When these monolayers with distinct dipole moments were transferred onto a gold-coated glass substrate, the resulting multilayer LB films exhibited the same surface potential, probably due to molecular rearrangement upon transfer.

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“…That the much larger amount of UAc needed to be introduced in the IEW subphase than in the Tris/NaCl subphase is probably due to the different pH value and ionic strength of the subphases, which affects both the solution chemistry of the UAc ions and the dissociation degree of the monolayer molecules (screening effect). UAc forms many different kinds of hydrolyzed species as a function of pH (Toth and Begun, 1981;Gorwyn and Barnes, 1990;Peñacorada et al, 1995). The different species were presented by Gorwyn and Barnes (1990), who studied the influence of UAc on phospholipid monolayers, using the following equilibria:…”

Section: Methodsmentioning

confidence: 99%

UV-Induced Reaction Kinetics of Dilinoleoylphosphatidylethanolamine Monolayers

Peltonen

1999

Biophysical Journal

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The UV-induced reactivity of dilinoleoylphosphatidylethanolamine (DLiPE) Langmuir and Langmuir-Blodgett films has been studied by in situ measurements of the changes in the mean molecular area, UV-vis and Fourier transform infrared spectroscopy, and atomic force microscopy (AFM). Optimum orientation and packing density of the DLiPE molecules in the monolayer were achieved by adding uranyl acetate to the subphase. A first-order reaction kinetic model was successfully fitted to the experimental reaction kinetics data obtained at a surface pressure of 30 mN/m. Topographical studies of LB films by AFM were performed on bilayer structures as a function of subphase composition and UV irradiation time. The orientational effect of the uranyl ions on the monolayer molecules was observed as an enhanced homogeneity of the freshly prepared monomeric LB films. However, the long-term stability of these films proved to be bad; clear reorganization and loss of a true monolayer structure were evidenced by the AFM images. This instability was inhibited for the UV-irradiated films, indicating that the UV irradiation gave rise to a cross-linked structure.

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Monolayers and Multilayers of Uranyl Arachidate. 1. Study of the Interaction of Dissolved Uranyl Ions with Arachidic Acid Langmuir Monolayers

Cited by 23 publications

References 2 publications

A Dendritic Amphiphile for Efficient Control of Biomimetic Calcium Phosphate Mineralization

A Dendritic Amphiphile for Efficient Control of Biomimetic Calcium Phosphate Mineralization

Surface Pressure and Surface Potential Isotherms of Ytterbium Bisphthalocyanine Langmuir Monolayers

UV-Induced Reaction Kinetics of Dilinoleoylphosphatidylethanolamine Monolayers

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