Phase behavior of the lecithin/water/isooctane and lecithin/water/decane systems

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Standard

Phase behavior of the lecithin/water/isooctane and lecithin/water/decane systems. / Angelico, R; Ceglie, A; Colafemmina, G; Delfine, F; Olsson, Ulf; Palazzo, G.

I: Langmuir, Vol. 20, Nr. 3, 2004, s. 619-631.

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Harvard

Angelico, R, Ceglie, A, Colafemmina, G, Delfine, F, Olsson, U & Palazzo, G 2004, 'Phase behavior of the lecithin/water/isooctane and lecithin/water/decane systems', Langmuir, vol. 20, nr. 3, s. 619-631. https://doi.org/10.1021/la035603d

APA

Angelico, R., Ceglie, A., Colafemmina, G., Delfine, F., Olsson, U., & Palazzo, G. (2004). Phase behavior of the lecithin/water/isooctane and lecithin/water/decane systems. Langmuir, 20(3), 619-631. https://doi.org/10.1021/la035603d

CBE

MLA

Vancouver

Author

Angelico, R ; Ceglie, A ; Colafemmina, G ; Delfine, F ; Olsson, Ulf ; Palazzo, G. / Phase behavior of the lecithin/water/isooctane and lecithin/water/decane systems. I: Langmuir. 2004 ; Vol. 20, Nr. 3. s. 619-631.

RIS

TY - JOUR

T1 - Phase behavior of the lecithin/water/isooctane and lecithin/water/decane systems

AU - Angelico, R

AU - Ceglie, A

AU - Colafemmina, G

AU - Delfine, F

AU - Olsson, Ulf

AU - Palazzo, G

PY - 2004

Y1 - 2004

N2 - The isothermal pseudo-ternary-phase diagram was determined at 25 degreesC for systems composed of lecithin, water, and, as oil, either isooctane or decane. This was accomplished by a combination of polarizing microscopy, small-angle X-ray scattering, and NMR techniques. The lecithin-rich region of the phase diagram is dominated by a lamellar liquid-crystalline phase (L-alpha). For lecithin contents less than 60% and low hydration (mole ratio water/lecithin = W-0 < 5.5), the system forms a viscous gel of branched cylindrical reverse micelles. With increase in the water content, the system phase separates into two phases, which is either gel in equilibrium with essentially pure isooctane (for lecithin < 25%) or a gel in equilibrium with L-alpha, (for lecithin > 25%). These two-phase regions are very thin with respect to water dilution. For 8 < W-0 < 54 very stable water-in-oil emulsions form. It is only after ripening for more than I year that the large region occupied by the emulsion reveals a complex pattern of stable phases. Moving along water dilution lines, one finds (i) the coexistence of gel, isooctane and L-alpha,(ii) equilibrium between reverse micelles and spherulites, and, finally, (iii) disconnected reverse micelles that fail to solubilize water for W-0 > 54. This results in a Winsor II phase equilibrium at low lecithin content, while for lecithin > 20% the neat water is in equilibrium with a reverse hexagonal phase and an isotropic liquid-crystalline phase. The use of the decane as oil does not change the main features of the phase behavior.

AB - The isothermal pseudo-ternary-phase diagram was determined at 25 degreesC for systems composed of lecithin, water, and, as oil, either isooctane or decane. This was accomplished by a combination of polarizing microscopy, small-angle X-ray scattering, and NMR techniques. The lecithin-rich region of the phase diagram is dominated by a lamellar liquid-crystalline phase (L-alpha). For lecithin contents less than 60% and low hydration (mole ratio water/lecithin = W-0 < 5.5), the system forms a viscous gel of branched cylindrical reverse micelles. With increase in the water content, the system phase separates into two phases, which is either gel in equilibrium with essentially pure isooctane (for lecithin < 25%) or a gel in equilibrium with L-alpha, (for lecithin > 25%). These two-phase regions are very thin with respect to water dilution. For 8 < W-0 < 54 very stable water-in-oil emulsions form. It is only after ripening for more than I year that the large region occupied by the emulsion reveals a complex pattern of stable phases. Moving along water dilution lines, one finds (i) the coexistence of gel, isooctane and L-alpha,(ii) equilibrium between reverse micelles and spherulites, and, finally, (iii) disconnected reverse micelles that fail to solubilize water for W-0 > 54. This results in a Winsor II phase equilibrium at low lecithin content, while for lecithin > 20% the neat water is in equilibrium with a reverse hexagonal phase and an isotropic liquid-crystalline phase. The use of the decane as oil does not change the main features of the phase behavior.

U2 - 10.1021/la035603d

DO - 10.1021/la035603d

M3 - Article

VL - 20

SP - 619

EP - 631

JO - Langmuir

JF - Langmuir

SN - 0743-7463

IS - 3

ER -