The effect of amphiphilic counterions on the gel-fluid phase transition of the lipid bilayer

The phase diagram of high-pressure hydrogen is of great interest for fundamental research, planetary physics, and energy applications. A first-order phase transition in the fluid phase between a molecular insulating fluid and a monoatomic metallic fluid has been predicted. The existence and precise location of the transition line is relevant for planetary models. Recent experiments reported contrasting results about the location of the transition. Theoretical results based on density functional theory are also very scattered. We report highly accurate coupled electron–ion Monte Carlo calculations of this transition, finding results that lie between the two experimental predictions, close to that measured in diamond anvil cell experiments but at 25–30 GPa higher pressure. The transition along an isotherm is signaled by a discontinuity in the specific volume, a sudden dissociation of the molecules, a jump in electrical conductivity, and loss of electron localization.

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Pressure dependence of the lipid bilayer phase transition

Biochemistry ◽

10.1021/bi00714a012 ◽

1974 ◽

Vol 13 (17) ◽

pp. 3494-3496 ◽

Cited By ~ 59

Author(s):

K. R. Srinivasan ◽

Robert L. Kay ◽

J. F. Nagle

Keyword(s):

Phase Transition ◽

Lipid Bilayer ◽

Pressure Dependence

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The solid-fluid phase transition: contribution of small watermelons

Journal of Physics C Solid State Physics ◽

10.1088/0022-3719/7/20/009 ◽

1974 ◽

Vol 7 (20) ◽

pp. 3723-3736 ◽

Cited By ~ 6

Author(s):

C A Croxton

Keyword(s):

Phase Transition ◽

Fluid Phase

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Impurity-Modulated Interface Formation in Lipid Bilayer Membranes Near the Chain-Melting Phase Transition

Phase Transitions in Soft Condensed Matter - NATO ASI Series ◽

10.1007/978-1-4613-0551-4_26 ◽

1989 ◽

pp. 283-288

Author(s):

John Hjort Ipsen ◽

Ole G. Mouritsen ◽

Leonor Cruzeiro-Hansson

Keyword(s):

Phase Transition ◽

Lipid Bilayer ◽

Lipid Bilayer Membranes ◽

Interface Formation ◽

Bilayer Membranes

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Variation of thermal conductivity of DPPC lipid bilayer membranes around the phase transition temperature

Journal of The Royal Society Interface ◽

10.1098/rsif.2017.0127 ◽

2017 ◽

Vol 14 (130) ◽

pp. 20170127 ◽

Cited By ~ 11

Author(s):

Sina Youssefian ◽

Nima Rahbar ◽

Christopher R. Lambert ◽

Steven Van Dessel

Keyword(s):

Phase Transition ◽

Thermal Conductivity ◽

Thermal Properties ◽

Transition Temperature ◽

Lipid Bilayer ◽

Lipid Bilayers ◽

Phase Transition Temperature ◽

Temperature Gradients ◽

Phase Behaviour ◽

Gel Phase

Given their amphiphilic nature and chemical structure, phospholipids exhibit a strong thermotropic and lyotropic phase behaviour in an aqueous environment. Around the phase transition temperature, phospholipids transform from a gel-like state to a fluid crystalline structure. In this transition, many key characteristics of the lipid bilayers such as structure and thermal properties alter. In this study, we employed atomistic simulation techniques to study the structure and underlying mechanisms of heat transfer in dipalmitoylphosphatidylcholine (DPPC) lipid bilayers around the fluid–gel phase transformation. To investigate this phenomenon, we performed non-equilibrium molecular dynamics simulations for a range of different temperature gradients. The results show that the thermal properties of the DPPC bilayer are highly dependent on the temperature gradient. Higher temperature gradients cause an increase in the thermal conductivity of the DPPC lipid bilayer. We also found that the thermal conductivity of DPPC is lowest at the transition temperature whereby one lipid leaflet is in the gel phase and the other is in the liquid crystalline phase. This is essentially related to a growth in thermal resistance between the two leaflets of lipid at the transition temperature. These results provide significant new insights into developing new thermal insulation for engineering applications.

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