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Przykaza K, Jurak M, Wiącek AE. Effect of naproxen on the model lipid membrane formed on the water-chitosan subphase. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184099. [PMID: 36493856 DOI: 10.1016/j.bbamem.2022.184099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 10/15/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022]
Abstract
Non steroidal anti-inflammatory drugs (NSAIDs) are those of the most common over the counter (OTC) medications widely used by millions of people every day. Unfortunately, despite their popularity those drugs can cause serious side effects in the digestive system (ulcers, bleeding, and pain). These inconveniences are caused by the changes in the structures of the outer phospholipid layers of gastric mucus and mucosa. As a result the H+ ions from the stomach acid can pass easily through these natural protective barriers and damage the epithelial cells which causes ulcers and bleeding. Chitosan as a polysaccharide known for its unique biocompatibility, drug delivery possibilities and wound healing effect has been chosen to examine if it can induce the reduction of undesirable effects of naproxen. This paper focuses on the interactions of the naproxen with a model biological membrane with and without the presence of chitosan. Applying the Langmuir technique coupled with the surface potential measurements and the Brewster angle microscope imaging allowed to characterize successfully examined systems in terms of the monolayer compressibility, thickness, stability, electric properties and morphology. The results proved that the presence of naproxen alters the mechanical and electrical properties of the model membrane depending on its surface pressure. Moreover, the addition of chitosan to the lipid-drug system causes significant changes in the properties of the layer, i.e. a reduction of its compressibility, thickness and morphology modification. Nevertheless, chitosan suppresses some changes induced by naproxen such as alteration of the apparent dipole moment and film stability.
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Affiliation(s)
- Kacper Przykaza
- Department of Interfacial Phenomena, Institute of Chemical Sciences, Faculty of Chemistry, University of Maria Curie-Skłodowska, Maria Curie-Skłodowska Sq. 3, 20031 Lublin, Poland; Department of Bioanalytics, Faculty of Biomedicine, Medical University of Lublin, Kazimierza Jaczewskiego St. 8b, 20-090 Lublin, Poland.
| | - Małgorzata Jurak
- Department of Interfacial Phenomena, Institute of Chemical Sciences, Faculty of Chemistry, University of Maria Curie-Skłodowska, Maria Curie-Skłodowska Sq. 3, 20031 Lublin, Poland
| | - Agnieszka Ewa Wiącek
- Department of Interfacial Phenomena, Institute of Chemical Sciences, Faculty of Chemistry, University of Maria Curie-Skłodowska, Maria Curie-Skłodowska Sq. 3, 20031 Lublin, Poland
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Kale SK, Cope AJ, Goggin DM, Samaniuk JR. A miniaturized radial Langmuir trough for simultaneous dilatational deformation and interfacial microscopy. J Colloid Interface Sci 2021; 582:1085-1098. [PMID: 32932179 DOI: 10.1016/j.jcis.2020.08.053] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 08/12/2020] [Accepted: 08/13/2020] [Indexed: 12/29/2022]
Abstract
INNOVATION Interfacial rheological properties of complex fluid-fluid interfaces are strongly influenced by the film microstructure. Experimental investigations for correlating interfacial morphology and rheology are notoriously challenging. A miniaturized radial Langmuir trough was developed to study complex fluid-fluid interfaces under purely dilatational deformations that operates in tandem with a conventional inverted microscope for simultaneous interfacial visualization. EXPERIMENTS Two materials were investigated at an air-water interface: poly(tert-butyl methacrylate) (PtBMA) and dipalmitoylphosphatidylcholine (DPPC). Surface pressure measurements made in the radial Langmuir trough were compared with a commercial rectangular Langmuir trough. Interfacial in situ visualization for each material was performed during the compression cycle in the radial trough. Challenges associated with the small size of the radial Langmuir trough, such as the influence of capillary deformation on the measured surface pressure, are also quantified. FINDINGS Measured surface pressures between the newly developed radial trough and the rectangular Langmuir trough compare well. Micrographs obtained in the radial Langmuir trough were used to obtain film properties such as Young's modulus. The new advance in colloid and interface science is the ability to capture structure-property relationships of planar interfaces using microscopy and purely dilatational deformation. This will advance the development of constitutive modeling of complex fluid-fluid interfaces.
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Affiliation(s)
- Shalaka K Kale
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO 80401, USA
| | - Andrew J Cope
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO 80401, USA
| | - David M Goggin
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO 80401, USA
| | - Joseph R Samaniuk
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO 80401, USA
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3
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Vollhardt D, Dobner B, Brezesinski G. Influence of linkage type (ether or ester) on the monolayer characteristics of single-chain glycerols at the air-water interface. Phys Chem Chem Phys 2020; 22:23207-23214. [PMID: 33029597 DOI: 10.1039/d0cp04153j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
O-1-Alkylglycerols are ubiquitous constituents in various biological materials but their biological significance is still largely unknown. So far, reports about the striking role of structural features on the interfacial properties of 1-O-alkylglycerol monolayers are quite rare. Therefore, in the present paper 1-O-alkylglycerol monolayers are comprehensively characterized on mesoscopic and molecular scales in the accessible ranges of temperature and surface pressure. Two Bragg peaks found for the condensed monolayer phase of the racemates at all pressures investigated indicate an orthorhombic structure with NN-tilted alkyl chains at lower pressures and NNN-tilted chains at higher pressures. In contrast to the continuous change of the tilt angle, as observed for many amphiphile monolayers, the tilt angle in 1-O-alkyl-rac-glycerol monolayers shows a jump-like transition from the L2 (NN tilt direction) to the Ov phase (NNN tilt direction) with the consequence of different slopes of 1/cos(t) vs. π in the two phases. This is the most striking difference to the behavior of the corresponding ester compound 1-stearoyl-rac-glycerol, having an oblique phase between the two orthorhombic phases L2 and Ov at low temperatures. The generic phase diagrams of the 1-O-alkyl-rac-glycerol and 1-acyl-rac-glycerol monolayers are essentially different. The influence of chirality on the monolayer structure is weak and becomes even weaker at high temperatures (rotator phases) and high lateral compression. The GIXD results of the enatiomeric pure compounds show the expected oblique lattice structure characterized by three Bragg peaks at almost all lateral pressures measured. The results of the GIXD studies are complemented by other monolayer characteristics such as π-A isotherms and mesoscopic domain topographies. The π-A isotherms of 1-O-alkyl-rac-glycerols are similar to those of the corresponding 1-acyl-rac-glycerols indicating that the change from the ester linkage to the ether linkage does not affect significantly the thermodynamic features. However, pronounced differences in the topological structure are observed. 1-O-hexadecyl-rac-glycerol monolayers form three-armed domains whereby each arm is subdivided into two segments with different molecular orientation. Also fascinating chiral discrimination effects are observable, demonstrated in the case of S-enantiomers by always clockwise curved spirals at the domain periphery. The 1 : 1 racemic mixtures exhibit both clockwise and counterclockwise curved spirals.
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Affiliation(s)
- D Vollhardt
- Max-Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany.
| | - B Dobner
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, D-06120 Halle, Germany
| | - G Brezesinski
- Institute for Applied Dermatopharmacy, Martin Luther University Halle-Wittenberg, Weinbergweg 23, D-06120 Halle, Germany
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Vollhardt D. Mesoscopic characterization of amphiphilic monoglycerol monolayers. Adv Colloid Interface Sci 2018; 258:36-46. [PMID: 30056937 DOI: 10.1016/j.cis.2018.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 07/19/2018] [Accepted: 07/19/2018] [Indexed: 10/28/2022]
Abstract
The introduction of the highly-sensitive imaging technique Brewster angle microscopy (BAM) has given rise to new knowledges about the mesoscopic topology and ordering of condensed phase domains formed in the two-phase coexistence region of Langmuir monolayers. Besides fatty acids, monoalkanoylglycerols are the most studied amphiphiles at the air-water interface. In this review, the mesoscopic characterization of amphiphilic monoglycerol monolayers is surveyed to demonstrate the striking effect of the position of the glycerol backbone at which the polar head group is substituted. Systematic mesoscopic studies of amphiphilic monoglycerol monolayers offer an outstanding possibility to highlight the dramatic effect of chemical structure variations at the position of the glycerol backbone and the substituted polar groups on the basis of the mesoscopic characterization. Small changes in the polarity by slight variation in the head group structure can dramatic affect shape and organization of the condensed phase domains. According to the importance of the 1-substituted monoglycerols, the effect of the chemical structure of the substituted polar group is highlighted with 4 selected examples. Further main topics discussed are chiral discrimination, kinetics of non-equilibrium structures, electrostatic interactions and a new geometric concept for explaining the topology of condensed phase domains.
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Effect of chirality on monoacylglycerol ester monolayer characteristics: 3-Monopalmitoyl- sn -glycerol. Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2016.08.065] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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6
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Vollhardt D, Brezesinski G. Effect of chirality on monoacylglycerol ester monolayer characteristics: 3-monostearoyl-sn-glycerol. Phys Chem Chem Phys 2017; 19:7009-7024. [DOI: 10.1039/c7cp00431a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effect of chirality on the thermodynamic behavior, morphological features, and 2D lattice structures of 3-monostearoyl-sn-glycerol monolayers is studied.
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Affiliation(s)
- D. Vollhardt
- Max-Planck Institute of Colloids and Interfaces
- D-14424 Potsdam/Golm
- Germany
| | - G. Brezesinski
- Max-Planck Institute of Colloids and Interfaces
- D-14424 Potsdam/Golm
- Germany
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Wieland DCF, Degen P, Zander T, Gayer S, Raj A, An J, Dėdinaitė A, Claesson P, Willumeit-Römer R. Structure of DPPC-hyaluronan interfacial layers - effects of molecular weight and ion composition. SOFT MATTER 2016; 12:729-740. [PMID: 26508354 DOI: 10.1039/c5sm01708d] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Hyaluronan and phospholipids play an important role in lubrication in articular joints and provide in combination with glycoproteins exceptionally low friction coefficients. We have investigated the structural organization of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) Langmuir layers at the solution-air interface at different length scales with respect to the adsorption of hyaluronan (HA). This allows us to assemble a comprehensive picture of the adsorption and the resulting structures, and how they are affected by the molecular weight of HA and the presence of calcium ions. Brewster angle microscopy and grazing incident diffraction were used to determine the lateral structure at the micro- and macro scale. The data reveals an influence of HA on both the macro and micro structure of the DPPC Langmuir layer, and that the strength of this effect increases with decreasing molecular weight of HA and in presence of calcium ions. Furthermore, from X-ray reflectivity measurements we conclude that HA adsorbs to the hydrophilic part of DPPC, but data also suggest that two types of interfacial structures are formed at the interface. We argue that hydrophobic forces and electrostatic interactions play important rules for the association between DPPC and HA. Surface pressure area isotherms were used to determine the influence of HA on the phase behavior of DPPC while electrophoretic mobility measurements were used to gain insight into the binding of calcium ions to DPPC vesicles and hyaluronan.
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Affiliation(s)
- D C Florian Wieland
- Helmholtz Zentrum Geesthacht, Institute for Materials Research, Max-Planck Straße 1, 21502 Geesthacht, Germany
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8
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Degen P, Wieland DCF, Strötges C. Mixed Layers of Nonionic Dendritic Amphiphiles and DPPC at the Water Surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:11851-11857. [PMID: 26447650 DOI: 10.1021/acs.langmuir.5b02702] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Nonionic dendritic amphiphiles that self-assemble into defined supramolecular aggregates are useful for the efficient solubilization of active agents, for example, in drug delivery. We investigated a new class of dendritic amphiphiles based on a hydrophilic polyol dendron head connected to a two-chain hydrophobic block. In analogy to phospholipids, these molecules form well-organized layers in bulk (vesicles) or at the water surface (Langmuir monolayer). The actual study focuses on the phase behavior and microscopic structure of mixed Langmuir layers of theses dendritic amphiphiles with the well-known phospholipid DPPC. The combination of surface pressure area isotherms with X-ray grazing incident diffraction and Brewster angle microscopy gives us information on the phase behavior of the mixed monolayers and the orientation of the amphiphiles inside the condensed domains with molecular resolution. We could prove that the dendritic generation and, by this, the headgroup size of the amphiphilic molecules have a significant influence on their interaction with DPPC at the air-water interface. Thus, our findings are important for the understanding of mixed lipid membranes in general as well as for the preparation of artificial membranes and vesicles with adjustable properties, e.g., their drug delivery potential.
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Affiliation(s)
- Patrick Degen
- Institut für Physikalische Chemie II, Technische Universität Dortmund , Otto-Hahn-Str. 6, 44227 Dortmund, Germany
| | - D C Florian Wieland
- Institut für Metallische Biomaterialien, Helmholtz Zentrum Geestacht , Max-Planck Straße 1, 21502 Geesthacht, Germany
| | - Christian Strötges
- Institut für Physikalische Chemie II, Technische Universität Dortmund , Otto-Hahn-Str. 6, 44227 Dortmund, Germany
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9
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Sandrino B, Tominaga TT, Nobre TM, Scorsin L, Wrobel EC, Fiorin BC, de Araujo MP, Caseli L, Oliveira ON, Wohnrath K. Correlation of [RuCl3(dppb)(VPy)] Cytotoxicity with its Effects on the Cell Membranes: An Investigation Using Langmuir Monolayers as Membrane Models. J Phys Chem B 2014; 118:10653-61. [DOI: 10.1021/jp505657x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- B. Sandrino
- Departamento
de Química, Universidade Estadual de Ponta Grossa, 84035-900, Ponta Grossa, PR, Brasil
| | - T. T. Tominaga
- Departamento
de Física, Universidade Estadual do Centro Oeste, 85040-080, Guarapuava, PR, Brasil
| | - T. M. Nobre
- Instituto
de Física de São Carlos, Universidade São Paulo, 13560-970, São Carlos, SP, Brasil
| | - L. Scorsin
- Departamento
de Química, Universidade Estadual de Ponta Grossa, 84035-900, Ponta Grossa, PR, Brasil
| | - E. C. Wrobel
- Departamento
de Química, Universidade Estadual de Ponta Grossa, 84035-900, Ponta Grossa, PR, Brasil
| | - B. C. Fiorin
- Departamento
de Química, Universidade Estadual de Ponta Grossa, 84035-900, Ponta Grossa, PR, Brasil
| | - M. P. de Araujo
- Departamento
de Química, Universidade Federal do Paraná, 81531-980, Curitiba, PR, Brasil
| | - L. Caseli
- Departamento
de Ciências Exatas e da Terra, Universidade Federal de São Paulo, 09972-270, Diadema, SP, Brasil
| | - O. N. Oliveira
- Instituto
de Física de São Carlos, Universidade São Paulo, 13560-970, São Carlos, SP, Brasil
| | - K. Wohnrath
- Departamento
de Química, Universidade Estadual de Ponta Grossa, 84035-900, Ponta Grossa, PR, Brasil
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10
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Eckert PK, Golz C, Degen P, Werner C, Rehage H, Strohmann C. Exploring the synthesis of a new group of chiral ammonium salts with specific configurations at the stereogenic nitrogen centers. Chemistry 2014; 20:3268-72. [PMID: 24615716 DOI: 10.1002/chem.201304433] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Indexed: 11/09/2022]
Abstract
A group of new chiral dications with a fixed, specific configuration at the stereogenic nitrogen center was created. Stereoselective synthesis and recrystallization give the diastereomerically and enantiomerically pure dications, including a chiral amphiphile with surface-active properties.
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Affiliation(s)
- Prisca K Eckert
- Anorganische Chemie, Technische Universität Dortmund (Germany), Fax: (+49) 231 755 3797
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11
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Palmer MR, Hagerman JM, Matano LM, DeWitt KM, Zhang Y. Thermodynamic analysis and fluorescence imaging of homochiral amino acid–amino acid interactions at the air/water interface. J Colloid Interface Sci 2013; 408:235-41. [DOI: 10.1016/j.jcis.2013.07.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 07/02/2013] [Accepted: 07/03/2013] [Indexed: 01/25/2023]
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12
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Pulido-Companys A, Albalat R, Garcia-Amorós J, Velasco D, Ignés-Mullol J. Supramolecular organization and heterochiral recognition in Langmuir monolayers of chiral azobenzene surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:9635-9642. [PMID: 23837787 DOI: 10.1021/la4006407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We study the self-assembly of novel azobenzene-based chiral surfactants at the air/water interface, and find that while the pure enantiomers lack the ability to organize in ordered mesophases, the racemic mixture spontaneously forms a hexatic phase at low lateral pressures, which we detect by means of Brewster angle microscopy. This work provides a unique example of heterochiral recognition in which the racemic monolayer is not only condensed with respect to the pure enantiomers, but causes an ordered mesophase to form. Although hexatic order vanishes at high surface pressures, long-range orientational order is regained for all compositions upon monolayer collapse, which proceeds through the formation of birefringent trilayers with a well-defined lateral microstructure, as revealed by atomic force microscopy.
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Affiliation(s)
- Alba Pulido-Companys
- Departament de Química Física, Institute of Nanoscience and Nanotechnology, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
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13
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Vysotsky YB, Fomina ES, Belyaeva EA, Vollhardt D, Fainerman VB, Miller R. Temperature effect on the monolayer formation of substituted alkanes at the air/water interface: a quantum chemical approach. J Phys Chem B 2012; 116:8996-9006. [PMID: 22731689 DOI: 10.1021/jp303617n] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An approach to calculation of the threshold temperature for spontaneous clusterization of substituted alkanes (amines, nitriles, alcohols, thioalcohols, saturated and unsaturated carboxylic acids, α-amino acids, carboxylic acid amides, and melamine derivatives) at the air/water interface with dependence on the alkyl chain length was developed. In the framework of this approach, four schemes for the description of the temperature dependencies of the thermodynamic parameters of clusterization of the concerned amphiphilic compounds were proposed. They use the data obtained previously in the framework of quantum chemical semiempirical PM3 method and differ from each other by the degree of their theoretical accuracy. It was shown that the threshold temperature for spontaneous clusterization of the regarded classes of substituted alkanes can be described using a fractionally linear function in dependence on the alkyl chain length. It was found that, in agreement with the presented experimental data, the effect of the alkyl chain elongation of the substituted alkanes by two methylene units correlates with the decrease of the subphase temperature (ΔT) by 10-20 K. The general shape of the obtained dependencies indicates that the difference in the ΔT values for the amphiphilic molecules decreases with increasing alkyl chain length. This implies that the contribution of the intermolecular CH···HC interactions between the alkyl chains of monolayer molecules should be a decisive factor.
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Affiliation(s)
- Yu B Vysotsky
- Donetsk National Technical University, 58 Artema Str., 83000 Donetsk, Ukraine
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14
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Roldán-Carmona C, Giner-Casares JJ, Pérez-Morales M, Martín-Romero MT, Camacho L. Revisiting the Brewster Angle Microscopy: the relevance of the polar headgroup. Adv Colloid Interface Sci 2012; 173:12-22. [PMID: 22397863 DOI: 10.1016/j.cis.2012.02.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 02/15/2012] [Accepted: 02/15/2012] [Indexed: 11/29/2022]
Abstract
The Brewster Angle Microscopy (BAM) is a powerful microscopy technique allowing the in situ visualization of the morphology of Langmuir monolayers at the air/water interface. The use of the BAM for attaining structural insights in the molecular arrangement of the Langmuir monolayers is widespread. In this review, we examine the reflection of a Langmuir monolayer under a rather different perspective than classical: the influence of the polar headgroup of the amphiphiles in the BAM images is taken into account. The relevance of the polar headgroup as the main cause of the BAM features has been the focus of a reduced number of BAM studies. An emerging experimental and theoretical framework from recent bibliography is discussed. Different theoretical scenarios are considered, concerning the size and absorption of radiation of the polar headgroup. Two qualitative examples showing physical phenomena regarding the reflectivity changes in a BAM experiments are discussed. The anisotropy in the BAM images as inner textures is of special interest. Quantitative structural information of the molecular arrangement of the monolayer is obtained by simulating the textures of the domains observed. The quantitative assessment of the detailed molecular arrangement of the polar headgroup by BAM is highly valuable, as this information can hardly be obtained from other experimental techniques. The procedure for extracting quantitative structural data from the experimental BAM pictures is revised in detail from the recent bibliography for further application of this model to different Langmuir monolayers.
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Affiliation(s)
- Cristina Roldán-Carmona
- Department of Physical Chemistry and Applied Thermodynamics, University of Córdoba, Campus de Rabanales, Edificio Marie Curie, Córdoba E-14014, Spain
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15
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Jiménez-Millán E, Giner-Casares JJ, Muñoz E, Martín-Romero MT, Camacho L. Self-assembly of Acridine Orange into H-aggregates at the air/water interface: tuning of orientation of headgroup. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:14888-14899. [PMID: 22029424 DOI: 10.1021/la2030236] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The surface active derivative of the organic dye Acridine Orange (N-10-dodecyl-acridine orange (DAO)) has been included in mixed Langmuir monolayers with stearic acid (SA). The maximum relative content on DAO for a stable mixed monolayer is a molar ratio of X(DAO) = 0.5. Brewster angle microscopy (BAM) reveals a high homogeneity at the micrometer level for the mixed monolayer in equimolar proportion (X(DAO) = 0.5), whereas the appearance of domains occurs for lower content of DAO, i.e., X(DAO) = 0.2 and 0.1. The aggregation of the DAO headgroup leads to well-defined H-aggregates at the air/water interface for those mixed monolayers with a low content of DAO. However, for the mixed monolayers enriched in DAO, e.g., X(DAO) = 0.5, the molecular crowding prevents the formation of defined supramolecular structures. Molecular organization and tilting of the DAO headgroup is quantitatively analyzed by in situ UV-visible reflection spectroscopy. The formation of H-aggregates of the DAO headgroup can be reversibly tuned with the applied surface pressure. A molecular mechanism for the conformational rearrangement of the DAO molecule is proposed using RM1 quantum semiempirical calculations.
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Affiliation(s)
- Eugenio Jiménez-Millán
- Department of Physical Chemistry and Applied Thermodynamics, University of Córdoba, Campus de Rabanales, Edificio Marie Curie, Córdoba, Spain E-14014
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16
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Jiménez-Millan E, Giner-Casares JJ, Martín-Romero MT, Brezesinski G, Camacho L. Chiral Textures inside 2D Achiral Domains. J Am Chem Soc 2011; 133:19028-31. [DOI: 10.1021/ja206037k] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Eugenio Jiménez-Millan
- Department of Physical Chemistry, University of Córdoba, Campus de Rabanales, E-14014 Córdoba, Spain
| | - Juan J. Giner-Casares
- Department of Physical Chemistry, University of Córdoba, Campus de Rabanales, E-14014 Córdoba, Spain
- Department of Interfaces, Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14476 Potsdam, Germany
| | - María T. Martín-Romero
- Department of Physical Chemistry, University of Córdoba, Campus de Rabanales, E-14014 Córdoba, Spain
| | - Gerald Brezesinski
- Department of Interfaces, Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14476 Potsdam, Germany
| | - Luis Camacho
- Department of Physical Chemistry, University of Córdoba, Campus de Rabanales, E-14014 Córdoba, Spain
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