Surface Properties of Novel Surfactant, Dihexadecyl Gemini Phosphate, Monolayers on Water Surface by Dropping Method

Kobayashi, Yusuke; Amano, Takahiko; Taga, Keijiro; Yamämoto, Yasushi; Shervani, Zameer; Yamamoto, Masato

doi:10.4236/jbpc.2017.84004

Cited by 4 publications

(5 citation statements)

References 21 publications

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“…This is calculated by drawing a tangent to the Langmuir isotherm after the crystallization plateau and extrapolation to zero surface pressure. The value is almost equal to the space required for a phosphate group (~24 Å 2 ) [ 44 , 45 ], but significantly larger than the area of a methylene sequence in zig-zag conformation (19 Å 2 ) or in the rotator phase (21 Å 2 ) [ 46 ]. Since the CH 2 sequences are not sufficiently long for back folding, more likely is a Langmuir monolayer formation for PEs where every second phosphoester defect is located on the water surface, while the hydrophobic methylene sequences (20–28 CH 2 units) avoid water contact in the air.…”

Section: Resultsmentioning

confidence: 99%

Crystallization of Poly(ethylene)s with Regular Phosphoester Defects Studied at the Air–Water Interface

et al. 2020

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Poly(ethylene) (PE) is a commonly used semi-crystalline polymer which, due to the lack of polar groups in the repeating unit, is not able to form Langmuir or Langmuir–Blodgett (LB) films. This problem can be solved using PEs with hydrophilic groups arranged at regular distances within the polymer backbone. With acyclic diene metathesis (ADMET) polymerization, a tool for precise addition of polar groups after a certain interval of methylene sequence is available. In this study, we demonstrate the formation of Langmuir/LB films from two different PEs with regular phosphoester groups, acting as crystallization defects in the main chain. After spreading the polymers from chloroform solution on the water surface of a Langmuir trough and solvent evaporation, the surface pressure is recorded during compression under isothermal condition. These π‐A isotherms, surface pressure π vs. mean area per repeat unit A, show a plateau zone at surface pressures of ∼(6 to 8) mN/m, attributed to the formation of crystalline domains of the PEs as confirmed by Brewster angle and epifluorescence microscopy. PE with ethoxy phosphoester defects (Ethoxy-PPE) forms circular shape domains, whereas Methyl-PPE-co-decadiene with methyl phosphoester defects and two different methylene sequences between the defects exhibits a film-like morphology. The domains/films are examined by atomic force microscopy after transferring them to a solid support. The thickness of the domains/films is found in the range from (2.4 to 3.2) nm depending on the transfer pressure. A necessity of chain tilt in the crystalline domains is also confirmed. Grazing incidence X-ray scattering measurements in LB films show a single Bragg reflection at a scattering vector qxy position of 15.1 nm−1 known from crystalline PE samples.

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Section: Resultsmentioning

confidence: 99%

Crystallization of Poly(ethylene)s with Regular Phosphoester Defects Studied at the Air–Water Interface

et al. 2020

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“…Brewster angle microscopy (BAM) for visualizing and capturing the morphology of the GD and Al monolayers was carried out using a BAM microscope (EMM633K; Filgen Inc., Nagoya, Japan) equipped with USB-CAP-type (GV-USB2; I-O DATA DEVICE, Inc., Ishikawa, Japan) image analysis software [13][14][15][16][17][18]. BAM showed the monolayer image that was formed due to the difference in refractive indices between the monolayer and the pure water phase.…”

Section: Brewster Angle Microscopy (Bam)mentioning

confidence: 99%

Morphology Observation of Two-Dimensional Monolayers of Model Proteins on Water Surface as Revealed by Dropping Method

Asada,

Tanaka,

Nagano

et al. 2024

Bioengineering

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We have investigated the morphology of two-dimensional monolayers of gramicidin-D (GD) and alamethicin (Al) formed on the water surface by the dropping method (DM) using surface tension measurement (STm), Brewster angle microscopy (BAM), and atomic force microscopy (AFM). Dynamic light scattering (DLS) revealed that GD in alcoholic solutions formed a dimeric helical structure. According to the CD and NMR spectroscopies, GD molecules existed in dimer form in methanol and lipid membrane environments. The STm results and BAM images revealed that the GD dimer monolayer was in a liquid expanded (LE) state, whereas the Al monolayer was in a liquid condensed (LC) state. The limiting molecular area (A0) was 6.2 ± 0.5 nm2 for the GD-dimer and 3.6 ± 0.5 nm2 for the Al molecule. The AFM images also showed that the molecular long axes of both the GD-dimer and Al were horizontal to the water surface. The stability of each monolayer was confirmed by the time dependence of the surface pressure (π) observed using the STm method. The DM monolayer preparation method for GD-dimer and Al peptide molecules is a useful technique for revealing how the model biological membrane’s components assemble in two dimensions on the water surface.

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“…Brewster angle microscopy (BAM) for visualizing the morphology of pure DPPC and DMPC and several mixed monolayers were carried out using a commercial BAM microscope (EMM633K; Filgen Inc., Nagoya, Japan) attached with an USB-CAP type (GV-USB2; I-O DATA DEVICE, INC., Kanazawa, Japan) imaging analysis software [16], [17], [18], [19], [20]. BAM shows the monolayer image arises from the difference in refractive index between the monolayer and the water phase.…”

Section: Brewster Angle Microscopy (Bam)mentioning

confidence: 99%

“…The structure of alkyl chains of DPPC and DMPC molecules in two mixed monolayers consisting of mole fraction of DMPC: 0.2, 0.8 and mole fraction of DMPC(d): 0.2 were studied by infrared external reflection spectroscopy (IERS) [16], [18], [19], [21]. An FT-IR spectrometer (FT-IR-600Plus; JASCO Int.…”

Section: E Infrared External Reflection Spectroscopy (Iers)mentioning

confidence: 99%

“…However, the study of DPPC-DMPC lipid combination is a pending issue. Therefore, in this communication, we have investigated the monolayer properties of two-dimensional DPPC-DMPC mixed monolayer at various mole fractions formed by the dropping method [16], [17], [18], [19] using surface tension measurement (STm), Brewster angle microscopy (BAM), and infrared external reflection spectroscopy (IERS).…”

Section: Introductionmentioning

confidence: 99%

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Morphological Behavior of DPPC-DMPC Two-dimensional Mixed Monolayer on Water Surface by Dropping Method

Watanabe

Uchida

Akatsuka

et al. 2022

EJCHEM

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We have investigated the morphology of dipalmitoyl phosphatidyl choline (DPPC)-dimyristoyl PC (DMPC) mixed monolayer formed on the water surface by the dropping method using surface tension measurement (STm), Brewster angle microscopy (BAM), and infrared external reflection spectroscopy (IERS). The limiting molecular area (A0) obtained by STm showed that the negative deviation at < mole fraction (xDMPC)= 0.4 whereas the positive deviation at > xDMPC =0.6 when DMPC was added to the DPPC monolayer. BAM images also showed that the condensed rigid monolayer at xDMPC < 0.4 changed to the expandable monolayer at xDMPC > 0.5. Moreover, IER spectra showed that the alkyl chains of both DPPC and DMPC molecules are in trans conformation in mixed monolayer at xDMPC =0.2 whereas gauche conformation existed at xDMPC = 0.8. Above findings have justified the transition of flexible gauche conformation alkyl chains of DMPC molecule into rigid trans conformation by the addition of DPPC molecule at xDMPC < 0.4 whereas alkyl chains retained flexible gauche conformation in both DPPC and DMPC molecules at xDMPC > 0.6.

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Surface Properties of Novel Surfactant, Dihexadecyl Gemini Phosphate, Monolayers on Water Surface by Dropping Method

Cited by 4 publications

References 21 publications

Crystallization of Poly(ethylene)s with Regular Phosphoester Defects Studied at the Air–Water Interface

Crystallization of Poly(ethylene)s with Regular Phosphoester Defects Studied at the Air–Water Interface

Morphology Observation of Two-Dimensional Monolayers of Model Proteins on Water Surface as Revealed by Dropping Method

Morphological Behavior of DPPC-DMPC Two-dimensional Mixed Monolayer on Water Surface by Dropping Method

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