CRITICAL SWELLING OF PHOSPHOLIPID-BILAYERS

We reexamine a critical phenomenon of phospholipids in lamellar phases . The question is, Is the anomalous divergence in the repeat spacing n ear the main transition the result of a divergence of the water layer or of the lipid bilayer? X-ray diffraction of DLPC lamellae was measur ed in partially dehydrated conditions. Its critical behavior is much m ore pronounced than the previously studied DMPC. The bilayer thickness was calculated from dehydrated conditions and then extrapolated to fu ll hydration. The results show that the anomalous divergence is primar ily due to the water layer expansion.