Bakshi Mandeep Singh, Singh Jasmeet, Kaur Gurinder
Department of Chemistry, Guru Nanak Dev University, Amritsar 143005, Punjab, India.
Chem Phys Lipids. 2005 Dec;138(1-2):81-92. doi: 10.1016/j.chemphyslip.2005.08.005. Epub 2005 Sep 21.
Surface tension (gamma) and time resolved fluorescence quenching (TRFQ) measurements have been performed on the binary mixtures of monomeric as well as dimeric alkylammonium bromides with l-alpha-dimyristoylphosphatidycholine (DMPC) and L-alpha-dipalmitoylphosphatidycholine (DPPC). The critical micelle concentration (cmc) has been evaluated from the gamma measurements. The gamma plots show two breaks in the gamma versus [total surfactant] curves in most of the cases. The first break (C1) has been attributed to the mixed vesicle formation process. The break down of the vesicles leads to the mixed micellization between the surfactant and phospholipid monomers at the second break (C2). The amount of surfactant used in the vesicle breakdown process (DeltaC) increases linearly with the increase in the amount of phospholipid and depends significantly on the hydrophobicities of the cationic components. The surface area per molecule (a) evaluated from the gamma plots indicates compact monolayer formation in the case of monomeric surfactants with lower hydrophobicities and reverse is observed for dimeric surfactants. The pyrene life time (tau) of the solubilized pyrene in the hydrophobic environment of mixed micelles, fully supports the conclusion that derived from a.
已对单体及二聚烷基溴化铵与l-α-二肉豆蔻酰磷脂酰胆碱（DMPC）和L-α-二棕榈酰磷脂酰胆碱（DPPC）的二元混合物进行了表面张力（γ）和时间分辨荧光猝灭（TRFQ）测量。通过γ测量评估了临界胶束浓度（cmc）。在大多数情况下，γ图显示γ与[总表面活性剂]曲线有两个断点。第一个断点（C1）归因于混合囊泡形成过程。囊泡的破裂导致在第二个断点（C2）处表面活性剂和磷脂单体之间形成混合胶束。囊泡破裂过程中使用的表面活性剂数量（ΔC）随磷脂数量的增加呈线性增加，并且显著取决于阳离子成分的疏水性。从γ图评估的每分子表面积（a）表明，疏水性较低的单体表面活性剂形成紧密单分子层，而二聚表面活性剂则观察到相反情况。溶解在混合胶束疏水环境中的芘的芘寿命（τ）完全支持从a得出的结论。
