Fluid phase lipid areas and bilayer thicknesses of commonly used phosphatidylcholines as a function of temperature

► Fluid bilayers composed of phosphatidylcholines are studied at several temperatures. ► Structural parameters are determined by neutron and X-ray scattering analysis. ► Thermal behavior of bilayer interactions is dominated by trans-gauche isomerization. ► Van der Waals interactions dictate chain length dependence in saturated lipids. ► Lipid chain dynamics depend strongly on double bond position.