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A W Neumann - One of the best experts on this subject based on the ideXlab platform.
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axisymmetric drop shape analysis as a film balance rate dependence of the collapse pressure and molecular area at close packing of 1 Octadecanol monolayers
Langmuir, 1996Co-Authors: Daniel Y Kwok, B Tadros, H Deol, Dieter Vollhardt, M A Cabrerizovilchez, R Miller, A W NeumannAbstract:The rate dependence of collapse pressure was studied systematically by axisymmetric drop shape analysis for an Octadecanol monolayer. Results suggest that collapse pressure is not uniquely dependen...
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axisymmetric drop shape analysis as a film balance rate dependence of the collapse pressure and molecular area at close packing of 1 Octadecanol monolayers
Langmuir, 1996Co-Authors: Daniel Y Kwok, B Tadros, H Deol, Dieter Vollhardt, M A Cabrerizovilchez, A W NeumannAbstract:The rate dependence of collapse pressure was studied systematically by axisymmetric drop shape analysis for an Octadecanol monolayer. Results suggest that collapse pressure is not uniquely dependent on the compression rate ; it depends on the amount of surfactant spread on the drop surface. It was also found that the shape of the surface pressure-area (π-A) isotherms changes with the rate of molecular area compression ; increasing the compression rate shifts the lower part of the isotherm to the right. It was also found that the values of the molecular area at collapse are more reproducible and consistent than the conventional extrapolation of the limiting molecular area ; the former was found to be 19.6 ± 0.1 A 2 /molecule, independent of both the amount of surfactant and motor speed, whereas the latter was found to be dependent on both the amount of surfactant and motor speed. All of these findings were explained by a morphological study of an Octadecanol monolayer using Brewster angle microscopy.
Maria Elisabete Darbello Zaniquelli - One of the best experts on this subject based on the ideXlab platform.
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Formation of thin luminescent Eu 3 þ -LB films by in situ coordination with 2,3,5,6-tetra(2 0 -pyridyl)pyrazine and 1-Octadecanol in pure and mixed Langmuir monolayers
2020Co-Authors: Fernanda P Fugisawa, Ana Paula Ramos, Osvaldo Antonio Serra, Sousa Filho, Maria Elisabete Darbello ZaniquelliAbstract:a b s t r a c t The in situ complexation between 2,3,5,6-tetra(2-pyridyl)pyrazine (tppz) molecules and europium ions at the air-liquid interface by means of mixed 1-Octadecanol Langmuir films is reported. These films were transferred to solid supports by means of the Langmuir-Blodgett (LB) technique. The EDS maps attested the homogeneity of the LB films as well as the presence of the europium ions. The mixed alcohol/tppz LB film contained a larger amount of europium ions as compared to the pure Octadecanol LB film. This work reports the production of a thin luminescent Eu 3 þ film containing europium ions using only alcohol molecules as ligands-an unexpected result, since it is well known that there is an occurrence of non-radiative deactivation of excited europium by hydroxyl groups. Europium ion multiple binding sites were detected from lifetime decay measurements of these films in the presence of tppz molecules
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formation of thin luminescent eu3 lb films by in situ coordination with 2 3 5 6 tetra 2 pyridyl pyrazine and 1 Octadecanol in pure and mixed langmuir monolayers
Journal of Luminescence, 2012Co-Authors: Fernanda P Fugisawa, Ana Paula Ramos, Paulo C De Sousa Filho, Osvaldo Antonio Serra, Maria Elisabete Darbello ZaniquelliAbstract:a b s t r a c t The in situ complexation between 2,3,5,6-tetra(2-pyridyl)pyrazine (tppz) molecules and europium ions at the air–liquid interface by means of mixed 1-Octadecanol Langmuir films is reported. These films were transferred to solid supports by means of the Langmuir–Blodgett (LB) technique. The EDS maps attested the homogeneity of the LB films as well as the presence of the europium ions. The mixed alcohol/tppz LB film contained a larger amount of europium ions as compared to the pure Octadecanol LB film. This work reports the production of a thin luminescent Eu 3 film containing europium ions using only alcohol molecules as ligands —an unexpected result, since it is well known that there is an occurrence of non-radiative deactivation of excited europium by hydroxyl groups. Europium ion multiple binding sites were detected from lifetime decay measurements of these films in the presence of tppz molecules.
Daniel Y Kwok - One of the best experts on this subject based on the ideXlab platform.
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axisymmetric drop shape analysis as a film balance rate dependence of the collapse pressure and molecular area at close packing of 1 Octadecanol monolayers
Langmuir, 1996Co-Authors: Daniel Y Kwok, B Tadros, H Deol, Dieter Vollhardt, M A Cabrerizovilchez, R Miller, A W NeumannAbstract:The rate dependence of collapse pressure was studied systematically by axisymmetric drop shape analysis for an Octadecanol monolayer. Results suggest that collapse pressure is not uniquely dependen...
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axisymmetric drop shape analysis as a film balance rate dependence of the collapse pressure and molecular area at close packing of 1 Octadecanol monolayers
Langmuir, 1996Co-Authors: Daniel Y Kwok, B Tadros, H Deol, Dieter Vollhardt, M A Cabrerizovilchez, A W NeumannAbstract:The rate dependence of collapse pressure was studied systematically by axisymmetric drop shape analysis for an Octadecanol monolayer. Results suggest that collapse pressure is not uniquely dependent on the compression rate ; it depends on the amount of surfactant spread on the drop surface. It was also found that the shape of the surface pressure-area (π-A) isotherms changes with the rate of molecular area compression ; increasing the compression rate shifts the lower part of the isotherm to the right. It was also found that the values of the molecular area at collapse are more reproducible and consistent than the conventional extrapolation of the limiting molecular area ; the former was found to be 19.6 ± 0.1 A 2 /molecule, independent of both the amount of surfactant and motor speed, whereas the latter was found to be dependent on both the amount of surfactant and motor speed. All of these findings were explained by a morphological study of an Octadecanol monolayer using Brewster angle microscopy.
Jérôme Pauly - One of the best experts on this subject based on the ideXlab platform.
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High Pressure Solid-Liquid Equilibrium of Fatty Alcohols Binary Systems from 1-Dodecanol, 1-Tetradecanol, 1-Hexadecanol, and 1-Octadecanol
Journal of Chemical & Engineering Data, 2015Co-Authors: Natália D.d. Carareto, Mariana C. Costa, Antonio J A Meirelles, Jérôme PaulyAbstract:The melting temperatures of four fatty alcohols, 1-dodecanol, 1-tetradecanol, 1-hexadecanol, and 1-Octadecanol, were measured at atmospheric pressure using a μDSC calorimeter and at higher pressures (up to 80 MPa) thanks to a dedicated microscope. The solid–liquid phase diagrams of six binary mixtures formed by these fatty alcohols, namely, 1-dodecanol + 1-tetradecanol, 1-dodecanol + 1-hexadecanol, 1-dodecanol + 1-Octadecanol, 1-tetradecanol + 1-hexadecanol, 1-tetradecanol + 1-Octadecanol, and 1-hexadecanol + 1-Octadecanol systems, were also measured using high pressure microscopy within the range of 0.1 MPa to 80 MPa. In addition, the phase diagrams of the 1-dodecanol + 1-tetradecanol, 1-tetradecanol + 1-hexadecanol, and 1-hexadecanol + 1-Octadecanol systems were also measured by DSC in order to compare the results obtained from the microscopy. On the basis of the experimental data, it could be concluded that the behavior of the phase diagrams is slightly affected by the pressure, even within very large ...
L Ventola - One of the best experts on this subject based on the ideXlab platform.
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polymorphism of n alkanols 1 heptadecanol 1 Octadecanol 1 nonadecanol and 1 eicosanol
Chemistry of Materials, 2002Co-Authors: L Ventola, M Ramirez, Teresa Calvet, And X Solans, M A Cuevasdiarte, Negrier P And, Denise Mondieig, J C Van Miltenburg And, H A J OonkAbstract:The polymorphism of 1-heptadecanol (C17H35OH), 1-Octadecanol (C18H37OH), 1-nonadecanol (C19H39OH), and 1-eicosanol (C20H41OH) has been studied by X-ray powder diffraction, differential scanning calorimetry (DSC), Raman scattering, and infrared spectroscopy (IR). At room-temperature two monoclinic forms, β and γ, are observed. For the n-alkanols with an even number of carbons the stable form is γ, whereas β is the stable form for the n-alkanols with an odd number of carbons. On heating, these phases transform to a monoclinic, rotator form R'IV at a few degrees below the melting point. A metastable β form is obtained by quenching from the melt for 1-Octadecanol and 1-eicosanol, which is isostructural with the β-phase of the odd alkanols. Cell parameters, temperatures, and enthalpies of the transitions are reported.
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heat capacities and derived thermodynamic functions of 1 Octadecanol 1 nonadecanol 1 eicosanol and 1 docosanol between 10 k and 370 k
Journal of Chemical & Engineering Data, 2001Co-Authors: Cees J Van Miltenburg, H A J Oonk, L VentolaAbstract:The molar heat capacities of the linear alcohols 1-Octadecanol (C18H38O), 1-nonadecanol (C19H40O), 1-eicosanol (C20H42O), and 1-docosonol (C22H46O) were measured from 10 K to 370 K. The derived absolute entropies were fitted as a function of the carbon number (n) in the linear chain. At 360 K the function is S°(360 K,n) = {117.52 + 38.328n} J·K-1·mol-1. A simple function was found for the heat capacity of the liquids. From the melting point to 370 K the liquid heat capacities can be represented within the measuring error with Cp,l(n,T) = {−450.41 + 36.4968n + 1.47317T} J·K-1·mol-1. The solid−solid phase transition in 1-Octadecanol was investigated in more detail, and the relative Gibbs energy curves of both solid phases and the liquid phase are presented.