Effects of Surface Pressure on the Properties of Langmuir Monolayers and Interfacial Water at the Air–Water Interface

Langmuir ◽  
2015 ◽  
Vol 31 (7) ◽  
pp. 2147-2156 ◽  
Author(s):  
Wei Lin ◽  
Anthony J. Clark ◽  
Francesco Paesani
Keyword(s):  
Surface Pressure ◽  
Langmuir Monolayers ◽  
Interfacial Water ◽  
Water Interface ◽  
Air Water Interface

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.

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.

scholarly journals Experimentally probing the libration of interfacial water: the rotational potential of water is stiffer at the air/water interface than in bulk liquid

2016 ◽  
Vol 18 (27) ◽  
pp. 18424-18430 ◽  
Author(s):  
Yujin Tong ◽  
Tobias Kampfrath ◽  
R. Kramer Campen
Keyword(s):  
Liquid Water ◽  
Bulk Liquid ◽  
Interfacial Water ◽  
Water Interface ◽  
Sum Frequency ◽  
Sum Frequency Spectroscopy ◽  
Air Water Interface ◽  
Vibrational Sum Frequency Spectroscopy

Vibrational sum frequency spectroscopy measurements reveal that the libration frequency of interfacial water is significantly higher than bulk liquid water, suggesting that water's rotational potential stiffens on moving from the bulk liquid to the air/water interface.

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