Water Surface Covering of Fluorinated Amphiphilic Triblock Copolymers:  Surface Pressure−Area and X-ray Reflectivity Investigations

Langmuir ◽  
2007 ◽  
Vol 23 (13) ◽  
pp. 6975-6982 ◽  
Author(s):  
Karsten Busse ◽  
Chiranjeevi Peetla ◽  
Jörg Kressler
2002 ◽  
Vol 06 (12) ◽  
pp. 806-811 ◽  
Author(s):  
Benjamin M. D. O'Driscoll ◽  
Jeremy L. Ruggles ◽  
Garry J. Foran ◽  
Binhua Lin ◽  
Ian R. Gentle

Langmuir monolayer films of the tetracationic porphyrin tetrakis(octadecyl-4-pyridinium)porphyrinatozinc(II) bromide on various salt containing subphases were analyzed using surface pressure-area isotherms and X-ray reflectivity. The use of these complementary techniques showed that the porphyrin molecules undergo changes in conformation upon compression. Two main phases were identified, one in which the porphyrin moiety is parallel to the subphase and one in which the porphyrin moiety is tilted out of the plane. The addition of different salts into the subphase brought about changes in film behaviour, which are explained in terms of a lyotropic series.


1985 ◽  
Vol 63 (10) ◽  
pp. 2742-2746 ◽  
Author(s):  
Robert Aveyard ◽  
Neil Carr ◽  
Helen Slezok

Surface pressure–area isotherms have been obtained for mono- and dioxyethylene dodecyl ethers both spread at the air–water surface and adsorbed at the heptane–water interface and results are compared with those for straight chain alkanols. At the heptane–water interface it appears that the ethyleneoxy groups are disposed parallel to the interface in fairly dilute films. The dual hydrophilic/hydrophobic nature of isolated CH2CH2O groups is demonstrated by showing that they give a negative contribution to the standard free energy of adsorption from both water and heptane to the heptane–water interface.


2021 ◽  
Vol 5 (2) ◽  
pp. 31
Author(s):  
Yohko F. Yano ◽  
Toshiaki Ina ◽  
Tomoya Uruga

Biological membrane is composed of lipid molecules, because of its fluidity, it is possible to carry out physiological functions. Therefore, it is important to study the hydrodynamic properties of membranes toward understanding its function. Here, we observed the dynamical behavior of a lipid monolayer on the water surface under Marangoni flow. By using X-ray reflectometry, we obtained the tilt angle of the hydrocarbon chains of the lipid at different surface pressures. Comparing them with the dynamical surface pressure under Marangoni flow, it was found that the lipid molecules in rotational rather than translational motion. At low surface pressure, the molecular tilt angle is reduced by 20 degrees, even though the molecular area is reduced by at most 10%.


Langmuir ◽  
2002 ◽  
Vol 18 (10) ◽  
pp. 3875-3879 ◽  
Author(s):  
Keitaro Kago ◽  
Takahiro Seki ◽  
Randolf R. Schücke ◽  
Emiko Mouri ◽  
Hideki Matsuoka ◽  
...  

2005 ◽  
Vol 492-493 ◽  
pp. 115-122 ◽  
Author(s):  
Saburo Uchida ◽  
Vijay T. Chitnis ◽  
Hideo Furuhashi ◽  
Toshio Yoshikawa ◽  
Akinori Maeda ◽  
...  

In the 21st century, the optical computation is likely to be the basic technology for processing lots of information at high speed. The aim of the present research work is to develop optical logic gates or memory chips. For this purpose, we have examined the suitability of organic nonlinear optical dye material Vanadyl-phthalocyanine (VOPc). Large single crystals of this material have been fabricated by using Molecular Beam Epitaxy (MBE) technique. The epitaxial films were formed on the substrate under optimum operating conditions. However, the epitixial growth is observed only up to a limited thickness. Above this thickness, the films become non-epitaxial, which can be improved by annealing. The reformation of the epitaxial films has been confirmed. We have also reported the effects of the environment of high temperature on the multilayered tetra-tert-butyl-Vanadyl-phthalocyanine ((t-bu)4VOPc) films, formed by Langmuir-Blodgett (LB) method. The solvent used to dissolve ((t-bu)4VOPc) was 1,2-dichloroethane. The monolayer on the surface of the water was transferred to a glass substrate by the vertical dipping method. If the multilayered stack is too thick, the molecular arrangement of the film may get disturbed. The improvement in the molecular arrangement of the LB films was examined and confirmed by measuring it’s nonlinear optical susceptibility, using Maker Fringe Method. Monolayer formation on water surface depends on the surface pressure-area isotherm. If this monolayer formation is not perfect, multiplayer stacks cannot be formed. The molecular films were aligned almost perpendicular to the substrate, as estimated from the limiting molecular area of surface pressure-area isotherm. The molecular organization of the monolayer on the substrate and the molecular structure of the multilayered ((t-bu)4VOPc) films are discussed.


Nano Letters ◽  
2011 ◽  
Vol 11 (9) ◽  
pp. 3906-3911 ◽  
Author(s):  
Cheng Wang ◽  
Dong Hyun Lee ◽  
Alexander Hexemer ◽  
Myung Im Kim ◽  
Wei Zhao ◽  
...  

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