scholarly journals Unusual Behavior of the Bipolar Molecule 25-Hydroxycholesterol at the Air/Water Interface—Langmuir Monolayer Approach Complemented with Theoretical Calculations

2020 ◽  
Vol 124 (6) ◽  
pp. 1104-1114 ◽  
Author(s):  
Anita Wnętrzak ◽  
Anna Chachaj-Brekiesz ◽  
Jan Kobierski ◽  
Katarzyna Karwowska ◽  
Aneta D. Petelska ◽  
...  
2019 ◽  
Vol 816 ◽  
pp. 312-317
Author(s):  
Alexandra O. Grigoreva ◽  
E.Y. Polozov ◽  
S.D. Zaitsev

Copolymerization of 2,2,3,3,4,4,5,5-octafluoropentyl acrylate (OFPA) and acrylic acid (AA), OFPA and tert-butyl acrylate (t-BA) in presence ofdibenzylcarbonotrithioate (BTC) and polymeric RAFT-agents was studied, reactivity ratios were calculated. It was shown that type of RAFT-agent can influence on chain microstructure of obtained polymers. Aggregation behavior of obtained amphiphilic copolymers with different microstructures at the air/water interface was characterized by the Langmuir monolayer technique. The effect of the microstructureand subphase pH on the isotherm curves were shown.


Langmuir ◽  
2017 ◽  
Vol 33 (30) ◽  
pp. 7548-7555 ◽  
Author(s):  
Wei Liu ◽  
Shanghao Li ◽  
Zhuguang Wang ◽  
Elsa C. Y. Yan ◽  
Roger M. Leblanc

2021 ◽  
Author(s):  
Balaji Sopanrao Dhopte ◽  
V. N. Lad

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.


2006 ◽  
Vol 05 (06) ◽  
pp. 787-793
Author(s):  
YOUNG SOO KANG ◽  
MI HYANG JEONG ◽  
SOO JA SHIN ◽  
YOUNG HWAN KIM ◽  
CHANG WOO KIM

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.


2013 ◽  
Vol 548 ◽  
pp. 509-516 ◽  
Author(s):  
Marina Nieto-Suárez ◽  
Nuria M. Blanco-Vila ◽  
Nuria Vila-Romeu

RSC Advances ◽  
2017 ◽  
Vol 7 (20) ◽  
pp. 11813-11820 ◽  
Author(s):  
Jonghyun Kim ◽  
Jin Chul Kim ◽  
Minh Dinh Phan ◽  
Heesoo Kim ◽  
Kwanwoo Shin ◽  
...  

Amphiphilic zwitterionic brush random copolymers bearing sulfobetaine groups at the bristle ends underwent segregation at the air–water interface, always forming only the Langmuir monolayer structure rather than any other structures.


Sign in / Sign up

Export Citation Format

Share Document