A Study on Langmuir Monolayers of Methacrylate Homo- and Copolymers Derivatized with Disperse Red Dyes

1997 ◽  
Vol 488 ◽  
Author(s):  
Anantharaman Dhanabalan ◽  
Débora Balogh ◽  
Carlos José Leopoldo Constantino ◽  
Antonio Riul ◽  
Osvaldo N. Oliveira ◽  
...  
Keyword(s):  
Surface Pressure ◽  
Critical Role ◽  
Langmuir Monolayers ◽  
Water Interface ◽  
Chlorine Substitution ◽  
Air Water Interface ◽  
Mole Percentage ◽  
Disperse Red 1 ◽  
Red Dye

AbstractWe report on the organization of different disperse red dye derivatized methacrylate homo- and copolymers as Langmuir monolayers at the air-water interface. The monolayers were investigated using surface pressure and surface potential isotherms. Methacrylic homopolymers containing disperse red-1 (HPDR1) and disperse red-13 (HPDR13) and methacrylic copolymers with different mole percentages of the dye and hydroxyethyl spacer groups were synthesized and characterized. A comparison of the monolayer characteristics of HPDR1 and HPDR13 revealed the influence of the chlorine substitution in the aromatic ring of the dye. Studies with copolymers indicated a clear transition in the monolayer behavior with the change of mole percentage of the dye incorporated in the polymer. While copolymers with low dye content (up to about 5 mole%) presented an expanded monolayer, the copolymers containing higher dye content (12% and above) formed a condensed monolayer similar to that of the homopolymer. These results indicated the critical role of the dye component in the polymer chain in forming the monolayer at the air-water interface.

Critical role of nanocomposites at air–water interface: From aqueous foams to foam-based lightweight functional materials

2021 ◽  
Vol 416 ◽  
pp. 129121
Author(s):  
Kai Yu ◽  
Bin Li ◽  
Huagui Zhang ◽  
Zhentao Wang ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Critical Role ◽  
Functional Materials ◽  
Water Interface ◽  
Aqueous Foams ◽  
Air Water Interface

scholarly journals Hysteresis of Isotherms of Mixed Monolayers of N-Octadecyl-N′-phenylthiourea and Stearic Acid at Air/Water Interface

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Siji Sudheesh ◽  
Jamil Ahmad ◽  
Girija S. Singh
Keyword(s):  
Stearic Acid ◽  
Surface Pressure ◽  
Surface Film ◽  
Langmuir Monolayers ◽  
The Other ◽  
Water Interface ◽  
Octadecanoic Acid ◽  
Air Water Interface ◽  
Pressure Area ◽  
Limiting Surface

Surface pressure area isotherms of Langmuir monolayers formed by spreading mixed solutions of varying concentrations of N-octadecyl-N′-phenylthiourea (OPT) and octadecanoic acid or stearic acid (SA) over air-water interface are described. Examination of the hysteresis behavior and an analysis of the limiting area per molecule of the isotherms show that when the spread solution has an excess of OPT, the limiting surface area is consistent with a monolayer composed of equimolar amounts of the two components. This indicates that any excess thiourea, which on its own does not form a stable monolayer, is squeezed out and is not part of the monolayer. On the other hand, when the spreading mixture has an excess of SA over OPT, the isotherm indicates that the entire originally spread material is incorporated into the surface film. In this case, the values of area/molecule indicate that the monolayer is composed of SA : OPT complex with a ratio of 1 : 1 together with the excess SA remaining in the monolayer.

Specific ion adsorption at the air/water interface: The role of hydrophobic solvation

2009 ◽  
Vol 479 (4-6) ◽  
pp. 173-183 ◽  
Author(s):  
Dominik Horinek ◽  
Alexander Herz ◽  
Lubos Vrbka ◽  
Felix Sedlmeier ◽  
Shavkat I. Mamatkulov ◽  
...  
Keyword(s):  
Ion Adsorption ◽  
Water Interface ◽  
Air Water Interface ◽  
Specific Ion Adsorption ◽  
Hydrophobic Solvation

scholarly journals Cholesterol provides nonsacrificial protection of membrane lipids from chemical damage at air–water interface

2018 ◽  
Vol 115 (13) ◽  
pp. 3255-3260 ◽  
Author(s):  
Xinxing Zhang ◽  
Kevin M. Barraza ◽  
J. L. Beauchamp
Keyword(s):  
Lipid Membranes ◽  
Membrane Lipids ◽  
Oh Radicals ◽  
Significant Finding ◽  
Water Interface ◽  
Unsaturated Lipids ◽  
Air Water Interface ◽  
Liquid Ordered ◽  
Ester Linkage

The role of cholesterol in bilayer and monolayer lipid membranes has been of great interest. On the biophysical front, cholesterol significantly increases the order of the lipid packing, lowers the membrane permeability, and maintains membrane fluidity by forming liquid-ordered–phase lipid rafts. However, direct observation of any influence on membrane chemistry related to these cholesterol-induced physical properties has been absent. Here we report that the addition of 30 mol % cholesterol to 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) or 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1′-rac-glycerol) (POPG) monolayers at the air–water interface greatly reduces the oxidation and ester linkage cleavage chemistries initiated by potent chemicals such as OH radicals and HCl vapor, respectively. These results shed light on the indispensable chemoprotective function of cholesterol in lipid membranes. Another significant finding is that OH oxidation of unsaturated lipids generates Criegee intermediate, which is an important radical involved in many atmospheric processes.

Sign in / Sign up

Export Citation Format

Share Document