Phase separation between phospholipids and grafted polymer chains onto a fluctuating membrane

摘要

We re-examine here the theoretical study of the phase separation between phospholipids and grafted long polymer chains onto a fluid membrane. The polymer chains are assumed to be anchored to the membrane by one extremity (anchor). The anchors are big amphiphile lipid molecules. The anchors and phospholipids forming the bilayer phase separate under the variation of a suitable parameter (temper- ature, pressure, membrane environment, . . . ). To investigate the demixtion transition, we elaborate a new approach that takes into account the membrane undulations. We show that these undulations have the ten- dency to induce additional attractive forces between anchors, and consequently, the separation transition is accentuated and occurs at high temperature. Quantitatively, we show that the membrane undulations contribute with an extra positive segregation parameter