SYNTHESIS OF AMPHIPHILIE TEMPO DERIVATIVE AND CHARACTERIZATION OF LANGMUIR MONOLAYERS OF AMPHIPHILIC ALKYL-TEMPOs AT THE AIR/WATER INTERFACE

2006 ◽  
Vol 05 (06) ◽  
pp. 787-793
Author(s):  
YOUNG SOO KANG ◽  
MI HYANG JEONG ◽  
SOO JA SHIN ◽  
YOUNG HWAN KIM ◽  
CHANG WOO KIM
Keyword(s):  
Alkyl Chain ◽  
Langmuir Monolayers ◽  
Langmuir Monolayer ◽  
Water Interface ◽  
Brewster Angle Microscopy ◽  
Collapse Pressure ◽  
Air Water Interface ◽  
Pressure Area ◽  
Hydrophobic Tail

The amphiphilic TEMPO molecules consist of two dissimilar parts. One part is hydrophilic (head) and the rest part is hydrophobic (tail). The derivatives of 4-alkaneamino-2, 2, 6, 6-tetramethyl-1-piperidinyloxy radical ( C n-amino-TEMPO, n = 14, 16, 18, 20, 22) was synthesized with 4-amino-TEMPO and carboxylic acid. The C n-amino-TEMPOs equilibrated at the air/water interface form Langmuir monolayer by classical Langmuir monolayer techniques. The stable monolayers of C 14-22-amino-TEMPOs were characterized by pressure–area isotherms. The features of collapse pressure of C 14-22-amino-TEMPOs were confirmed on alkyl chain length. Limiting area points and take-off area points from surface pressure-MMA isotherms were subjected to the influence of subphase. The monolayer of C 22-amino-TEMPO which has longer alkyl chain was characterized by Brewster Angle Microscopy. So we can confirm phase transition by BAM images as monolayer is expanding at the room temperature.

Characterization of Surface-Active Biofilm Protein BslA in Self-Assembling Langmuir Monolayer at the Air–Water Interface

Langmuir ◽  
2017 ◽  
Vol 33 (30) ◽  
pp. 7548-7555 ◽  
Author(s):  
Wei Liu ◽  
Shanghao Li ◽  
Zhuguang Wang ◽  
Elsa C. Y. Yan ◽  
Roger M. Leblanc
Keyword(s):  
Langmuir Monolayer ◽  
Water Interface ◽  
Self Assembling ◽  
Air Water Interface ◽  
Surface Active

scholarly journals Characterization of Monoolein Langmuir Monolayers Spread at The Salt Solution/Air Interface

2021 ◽  
Author(s):  
Balaji Sopanrao Dhopte ◽  
V. N. Lad
Keyword(s):  
Physicochemical Properties ◽  
Molecular Layer ◽  
Langmuir Monolayers ◽  
Langmuir Monolayer ◽  
Compression Isotherm ◽  
Water Interface ◽  
Air Interface ◽  
Special Groups ◽  
Air Water Interface ◽  
The Difference

Abstract The Langmuir monolayer is commonly described at interfaces for an insoluble homogenous single molecular layer. Langmuir monolayers have demonstrated various issues regarding soft matters and complex fluids by forming ideal uniform two-dimensional structures over the air-water interface. This monolayer has advantages for evaluating physicochemical properties at interfaces and, for the insoluble molecules, can be applied simultaneously to the different interaction occurrences at interfaces. For this experiment, monoolein lipid was used as a spreading solvent to create a Langmuir monolayer, and five different types of salt sub-phases were applied for the physicochemical properties’ interaction studies. On the air-water interface, the surface properties of monoolein lipids were investigated for interfacial phase behaviors, using the Wilhelmy plate pressure sensor technique compression isotherm (π-A). Data and analysis were also contributed to the correspondent, precise verification of physical state behavior with the surface pressure measurements on the interfaces through the compressibility modulus and the elasticity modulus parameters on the surface. In the experiments, the interfacial activity of the monoolein lipids was found to be stable on the aqueous sub-phase, while the area per molecule over the interface did not have much impact as a sub-phase with a change in salts. The repeatability and reproducibility of tests were affirmed by the difference in the Langmuir monolayer’s particular phase transition orientation behavior and the stability of colloidal lipid dispersion. However, Langmuir monolayer formation contributes to several special groups being restructured and is found to be a more remarkable natural process for their attractive organic dynamic structural properties over the interface, but the interfacial molecular dynamics have proven to be difficult to calculate.

scholarly journals Synthesis and monolayer film of a series of new twin-tailed gemini cationic surfactants at the air/water interface

2008 ◽  
Vol 6 (3) ◽  
pp. 477-481 ◽  
Author(s):  
Zhi Chen ◽  
Yujun Feng ◽  
Dongliang Zhou ◽  
Puxin Zhu ◽  
Dacheng Wu
Keyword(s):  
Surface Pressure ◽  
Gemini Surfactants ◽  
Limited Area ◽  
Initial Surface ◽  
Water Interface ◽  
Spacer Length ◽  
Collapse Pressure ◽  
Initial Area ◽  
Air Water Interface ◽  
Pressure Area

AbstractA series of new dimeric surfactants, twin-tailed gemini surfactants, 2(12)-s-2(12), were successfully prepared and characterized, and their monolayer films investigated by the measurement of surface pressure-area (π-A) and surface pressure-time (π-t) isotherms at the air/water interface by a Langmuir film balance. Compared to their monomeric counterparts, their collapse pressure (γcollapse) is smaller, whilst all the molecular area parameters are larger. The limited area (Alimited) and the initial area (Ainitial) of these twin-tailed gemini surfactants change with increasing spacer length s, and the surface pressure decreases with increasing time. It was also found that the higher the initial surface pressure, the larger the attenuation.

scholarly journals Characterization of Monoolein Langmuir Monolayers Spread at The Salt Solution/Air Interface

2021 ◽  
Author(s):  
Balaji Sopanrao Dhopte ◽  
V. N. Lad
Keyword(s):  
Physicochemical Properties ◽  
Molecular Layer ◽  
Langmuir Monolayers ◽  
Langmuir Monolayer ◽  
Compression Isotherm ◽  
Water Interface ◽  
Air Interface ◽  
Special Groups ◽  
Air Water Interface ◽  
The Difference

Abstract The Langmuir monolayer is commonly described at interfaces for an insoluble homogenous single molecular layer. Langmuir monolayers have demonstrated various issues regarding soft matters and complex fluids by forming ideal uniform two-dimensional structures over the air-water interface. This monolayer has advantages for evaluating physicochemical properties at interfaces and, for the insoluble molecules, can be applied simultaneously to the different interaction occurrences at interfaces. For this experiment, monoolein lipid was used as a spreading solvent to create a Langmuir monolayer, and five different types of salt sub-phases were applied for the physicochemical properties’ interaction studies. On the air-water interface, the surface properties of monoolein lipids were investigated for interfacial phase behaviors, using the Wilhelmy plate pressure sensor technique compression isotherm (π-A). Data and analysis were also contributed to the correspondent, precise verification of physical state behavior with the surface pressure measurements on the interfaces through the compressibility modulus and the elasticity modulus parameters on the surface. In the experiments, the interfacial activity of the monoolein lipids was found to be stable on the aqueous sub-phase, while the area per molecule over the interface did not have much impact as a sub-phase with a change in salts. The repeatability and reproducibility of tests were affirmed by the difference in the Langmuir monolayer’s particular phase transition orientation behavior and the stability of colloidal lipid dispersion. However, Langmuir monolayer formation contributes to several special groups being restructured and is found to be a more remarkable natural process for their attractive organic dynamic structural properties over the interface, but the interfacial molecular dynamics have proven to be difficult to calculate.

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.

Langmuir monolayer of hypocrellins and their amino substituted derivatives at the air/water interface: Brewster angle microscopy study

2001 ◽  
Vol 388 (1-2) ◽  
pp. 120-125
Author(s):  
Chunhong Tian ◽  
Xiaoli Wang ◽  
Tao Wu ◽  
Jianquan Shen ◽  
Manhua Zhang ◽  
...  
Keyword(s):  
Microscopy Study ◽  
Langmuir Monolayer ◽  
Brewster Angle ◽  
Water Interface ◽  
Brewster Angle Microscopy ◽  
Air Water Interface

scholarly journals Structure of DPPC Monolayers at the Air/Buffer Interface: A Neutron Reflectometry and Ellipsometry Study

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 507
Author(s):  
Javier Carrascosa-Tejedor ◽  
Andreas Santamaria ◽  
Daniel Pereira ◽  
Armando Maestro
Keyword(s):  
Structural Information ◽  
Langmuir Monolayers ◽  
Neutron Reflectometry ◽  
Model Systems ◽  
Angle Of Incidence ◽  
Water Interface ◽  
Brewster Angle Microscopy ◽  
Degree Of Hydration ◽  
Novel Approach ◽  
Air Water Interface

Langmuir monolayers of 1,2-dipalmitoyl-sn-glycerol-3-phosphocholine, known as DPPC, at the air/water interface are extensively used as model systems of biomembranes and pulmonary surfactant. The properties of these monolayers have been mainly investigated by surface pressure–area isotherms coupled with different complementary techniques such as Brewster angle microscopy, for example. Several attempts using neutron reflectometry (NR) or ellipsometry have also appeared in the literature. Here, we report structural information obtained by using NR and ellipsometry on DPPC monolayers in the liquid condensed phase. On one side, NR can resolve the thickness of the aliphatic tails and the degree of hydration of the polar headgroups. On the other side, ellipsometry gives information on the refractive index and, therefore, on the physical state of the monolayer. The thickness and surface excess obtained by multiple-angle-of-incidence ellipsometry (MAIE) is compared with the results from NR measurements yielding a good agreement. Besides, a novel approach is reported to calculate the optical anisotropy of the DPPC monolayer that depends on the orientation of the aliphatic chains. The results from both NR and ellipsometry are also discussed in the context of the existing results for DPPC monolayers at the air/water interface. The differences observed are rationalized by the presence of buffer molecules interacting with phospholipids.

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