Effect of Cholesterol and Other Additives on Viscosity, Self-Diffusion Coefficient, and Intramolecular Movements of Oleic Acid

Iwahashi, Makio; Umehara, Atsushi; Wakisaka, Kenichiro; Kasahara, Yuji; Minami, Hiroyuki; Matsuzawa, Hideyo; Shinzawa, Hideyuki; Ozaki, Yukihiro; Suzuki, Masao

doi:10.1021/jp0619538

Cited by 22 publications

(10 citation statements)

References 31 publications

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“…The value of D B , the bulk diffusion coefficient of Span 80 in Marcol 52 oil, is not known. Since the Span 80 molecule is not much larger than the alkanes in the oil, we may use as a rough estimate the self-diffusion coefficient of the tail of the Span 80 molecule, namely oleic acid, which gives D B ≈ 10 −10 m 2 /s (Iwahashi et al, 2007); of the same order of magnitude as e.g. the diffusion coefficient of C 12 E 6 surfactant in water (Lin et al, 2003).…”

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confidence: 99%

Influence of surfactants on the electrohydrodynamic stretching of water drops in oil

Ervik

Penne

Hellesø

et al. 2018

International Journal of Multiphase Flow

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In this paper we present experimental and numerical studies of the electrohydrodynamic stretching of a sub-millimetre-sized salt water drop, immersed in oil with added non-ionic surfactant, and subjected to a suddenly applied electric field of magnitude approaching 1 kV/mm. By varying the drop size, electric field strength and surfactant concentration we cover the whole range of electric capillary numbers (Ca E ) from 0 up to the limit of drop disintegration. The results are compared with the analytical result by G.I. Taylor (Proc. R. Soc. A 280, 383 (1964)) which predicts the asymptotic deformation as a function of Ca E . We find that the addition of surfactant damps the transient oscillations and that the drops may be stretched slightly beyond the stability limit found by Taylor. We proceed to study the damping of the oscillations, and show that increasing the surfactant concentration has a dual effect of first increasing the damping at low concentrations, and then increasing the asymptotic deformation at higher concentrations. We explain this by comparing the Marangoni forces and the interfacial tension as the drops deform. Finally, we have observed in the experiments a significant hysteresis effect when drops in oil with large concentration of surfactant are subjected to repeated deformations with increasing electric field strengths. This effect is not attributable to the flow nor the interfacial surfactant transport.

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Influence of surfactants on the electrohydrodynamic stretching of water drops in oil

Ervik

Penne

Hellesø

et al. 2018

International Journal of Multiphase Flow

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“…These characteristic APS peaks are also observed in both OA‐modified APS [Figure (b)] and silane‐modified APS [Figure (c)]. The broad stretching vibration peak at 1650–1750 cm −1 is assigned to the carboxyl group of OA [Figure (b)] . The absorption peaks of asymmetry stretching vibration of CH at 2971, 2927 cm −1 , which exist in the spectra of Figure (c), are attributed to KH‐570 [Figure (d)].…”

Section: Resultsmentioning

confidence: 90%

A facile strategy to improve the encapsulation efficiency of polymer microcapsules containing water‐soluble salt cores

Zuo

Zhang

Yuan

et al. 2017

J of Applied Polymer Sci

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To increase the encapsulation efficiency of microcapsules composed of water‐soluble salt cores and hydrophobic material shells, we herein reported a facile and versatile strategy to improve the hydrophobicity of water‐soluble salts [i.e., ammonium persulfate (APS)] by surface modification of APS using oleic acid or silane coupling agent, respectively. The results confirmed that the hydrophobicity of the two modified APS had been successfully improved compared with that of non‐modified APS. Moreover, the two modified APS could be effectively encapsulated into hydrophobic polystyrene and the encapsulation efficiency of the resulting microcapsules goes up significantly. This study was expected to drive progress in the preparation technology of microcapsules which comprise water‐soluble salts as cores and hydrophobic polymer materials as shells in many industrial application fields. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45294.

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“…OA is a long-chain carboxylic acid that is an important component of biological substances, and has already been well characterized by using NIR and mid-IR spectroscopy. 24–31 The association and dissociation of OA in the liquid state has been particularly well studied. 24–27,30,31 Iwahashi et al 24 investigated the temperature dependence of the NIR band at 6919 cm −1 and found that the dissociation of dimers occurred even in the pure liquid state.…”

Section: Introductionmentioning

confidence: 99%

“…24–31 The association and dissociation of OA in the liquid state has been particularly well studied. 24–27,30,31 Iwahashi et al 24 investigated the temperature dependence of the NIR band at 6919 cm −1 and found that the dissociation of dimers occurred even in the pure liquid state. Shinzawa and Noda 30 recorded time-dependent mid-IR spectra of a binary mixture of OA and carbon tetrachloride by using the ATR method, and documented the dynamic behavior of OA molecules undergoing self-assembly into smectic liquid crystals in detail via 2D-COS in conjunction with an eigenvector manipulating transformation technique.…”

Section: Introductionmentioning

confidence: 99%

Two-Dimensional Heterospectral Correlation Analysis of Water and Liquid Oleic Acid Using an Online Near-Infrared/Mid-Infrared Dual-Region Spectrometer

et al. 2013

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Two-dimensional (2D) near-infrared (NIR) and mid-infrared (mid-IR) heterospectral correlation analyses were used to characterize temperature-dependent spectral variations of water and liquid oleic acid (OA), utilizing a dataset obtained with an online NIR/mid-IR dual-region spectrometer. The spectrometer facilitated sequential acquisition of both NIR (10 000-4000 cm(-1)) and mid-IR (5000-1200 cm(-1)) spectra, which compose the spectral dataset required for 2D NIR/mid-IR heterospectral correlation analysis. Both NIR and mid-IR spectra were obtained under the same conditions by using the same sample compartment, more quickly and easily than is possible when using existing spectrometers. Successful 2D NIR/mid-IR correlation analysis was performed with the data collected with this instrument to characterize the temperature dependence of the molecular structures of water and pure liquid OA. Temperature-induced NIR/mid-IR spectral changes for water and OA were analyzed in detail, and band assignments in the NIR and mid-IR regions were elucidated by 2D NIR/mid-IR heterospectral correlation analysis. The results of this study indicate that liquid water consists of two major species, strongly hydrogen-bonded species and weakly hydrogen-bonded species, as well as one minor species. Additionally, OA was found to form an intermolecularly hydrogen-bonded species in which a single hydrogen bond of the dimer was broken; a mid-IR band at 1724 cm(-1) was assigned to this species. Moreover, 2D NIR/mid-IR heterospectral correlation analysis revealed that NIR bands at 4690 and 4644 cm(-1) also arose from intermolecularly hydrogen-bonded species. These results demonstrate that 2D NIR/mid-IR heterospectral correlation analysis is useful not only for NIR band assignments, but also for molecular structure studies. The spectrometer we developed makes this analysis even more accessible.

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Effect of Cholesterol and Other Additives on Viscosity, Self-Diffusion Coefficient, and Intramolecular Movements of Oleic Acid

Cited by 22 publications

References 31 publications

Influence of surfactants on the electrohydrodynamic stretching of water drops in oil

Influence of surfactants on the electrohydrodynamic stretching of water drops in oil

A facile strategy to improve the encapsulation efficiency of polymer microcapsules containing water‐soluble salt cores

Two-Dimensional Heterospectral Correlation Analysis of Water and Liquid Oleic Acid Using an Online Near-Infrared/Mid-Infrared Dual-Region Spectrometer

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