title: Slow relaxation process in the main transition of phosphatidylcholines studied with heat capacity spectroscopy. I. Multilamellar vesicles.
abstract: Extremely slow relaxation processes have been examined near the main transition of multilamellar vesicle samples of dimyristoylphosphatidylcholine (DMPC) and dipalmitoylphosphatidylcholine (DPPC) with a heat capacity spectroscopic technique. The dynamic heat capacity showed a significant frequency dependence in the studied frequency region of 0.5 mHz to 50 mHz. The relaxation observed here has been analyzed with the Cole-Cole equation. The mean relaxation times were 120 s in DMPC, and 260 s in DPPC. The relaxation showed a polydispersive character. The parameter beta was around 0.5 in both DMPC and DPPC.
authors.affiliation: Department of Physics, Faculty of Science, Tokyo Institute of Technology, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Yao
authors.forename: H
authors.initials: H
authors.lastname: Nagano
authors.forename: Y
authors.initials: Y
authors.lastname: Kawase
authors.forename: K
authors.initials: K
authors.lastname: Ema
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry*; D006358:Hot Temperature; D008081:Liposomes; D013057:Spectrum Analysis / Q000379:methods
chemical_list: D008081:Liposomes; D015060:1,2-Dipalmitoylphosphatidylcholine; D004134:Dimyristoylphosphatidylcholine