Surface pressure-area curves compression isotherm of sericin Langmuir monolayer

2007 ◽  
Vol 39 (5) ◽  
pp. 375-376 ◽  
Author(s):  
Yang Jianbin ◽  
Zhu Puxing ◽  
Wu Dacheng
Keyword(s):  
Surface Pressure ◽  
Langmuir Monolayer ◽  
Compression Isotherm ◽  
Pressure Area

Conformational changes in monolayers of a cationic amphiphilic porphyrin on saline subphases

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
Keyword(s):  
Conformational Changes ◽  
Surface Pressure ◽  
Langmuir Monolayer ◽  
Monolayer Films ◽  
X Ray ◽  
Pressure Area ◽  
Lyotropic Series ◽  
Complementary Techniques ◽  
Porphyrin Moiety

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.

Molecular Organization of Nonlinear Organic Films Laminated by Langmuir-Blodgett Method

2005 ◽  
Vol 492-493 ◽  
pp. 115-122 ◽  
Author(s):  
Saburo Uchida ◽  
Vijay T. Chitnis ◽  
Hideo Furuhashi ◽  
Toshio Yoshikawa ◽  
Akinori Maeda ◽  
...  
Keyword(s):  
Surface Pressure ◽  
Nonlinear Optical ◽  
Epitaxial Films ◽  
Operating Conditions ◽  
Molecular Organization ◽  
Optimum Operating ◽  
Monolayer Formation ◽  
Langmuir Blodgett ◽  
Molecular Arrangement ◽  
Pressure Area

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.

scholarly journals INTERACTION OF NANOSTRUCTURED LIPID CARRIERS WITH HUMAN MEIBUM

2019 ◽  
pp. 35-42
Author(s):  
Pattravee Niamprem ◽  
Thomas J. Milla ◽  
Burkhardt S. Schuett ◽  
S. P. Srinivas ◽  
Waree Tiyaboonchai
Keyword(s):  
Particle Size ◽  
Surface Pressure ◽  
Tear Film ◽  
Nanostructured Lipid Carriers ◽  
Langmuir Trough ◽  
Surface Activities ◽  
Lipid Films ◽  
Pressure Area ◽  
Surface Active ◽  
High Pressure Homogenizer

Objective: This study aimed to determine the possibility of nanostructured lipid carriers (NLCs) as a bionic tear film by determining the surface activities of the developed NLCs and their interaction with human meibomian lipid films. Methods: NLCs with different types of solid lipids and surfactants were prepared by a high-pressure homogenizer. The particle size was determined by dynamic light scattering. The surface activities of the NLCs and NLCs mixed with meibomian lipids were measured using a Langmuir trough and the resulting surface pressure area (Π-A) profiles were compared. These lipid films were further analyzed using fluorescence microscopy and scanning electron microscopy (SEM). Results: The particle size of prepared NLCs varied from 38–280 nm based on types of solid lipid and surfactant. All NLCs were highly surface active as indicated by their maximum surface pressure (Πmax). The Π-A profiles of meibum seeded with NLCs showed higher surface pressure than meibum alone and the shape of profiles were dominated by the meibomian lipids. These findings were in agreement with fluorescence and SEM micrographs, which revealed that the NLCs could adsorb and integrate to the meibomian lipid films as well as diffuse from the subphase to the lipid films. Conclusion: NLCs are surface active and can integrate with meibomian lipid films formed stable films. The type of interaction can be tailored by altering the solid lipids used in the formulation of the NLCs which could provide the means to develop efficient formulations for targeting dry eye disease related to a non-functional tear film lipid layer.

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