Biphasic Formation of 2D Nanomembranes by Photopolymerization of Diacetylene Lipids as Revealed by Infrared Difference Spectroscopy.
Biphasic Formation of 2D Nanomembranes by Photopolymerization of Diacetylene Lipids as Revealed by Infrared Difference Spectroscopy.
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DOI：
10.1021/acs.langmuir.9b00660
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发表时间：
2019-06
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影响因子：
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通讯作者：
Dominic Gilzer;Roland Hillmann;Lukas Goett-Zink;Jessica L. Klocke;Martina Viefhues;D. Anselmetti;T. Kottke
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作者：
Dominic Gilzer;Roland Hillmann;Lukas Goett-Zink;Jessica L. Klocke;Martina Viefhues;D. Anselmetti;T. Kottke
2D纳米膜通过为两个隔室之间的受控和快速运输提供基础，是有前途的过滤或分离材料。在界面处通过含二乙炔的脂质的UV光的聚合产生独立的2D纳米膜。在这里，我们分析了原位纳米膜形成的1，2-双（10，1,2-tricosadiynoyl）-sn-甘油-3-磷酸胆碱（DiynePC）和1-棕榈酰-2-（10，1,2-tricosadiynoyl）-sn-甘油-3-磷酸乙醇胺（PTPE）锗使用光诱导红外差光谱与衰减全反射，以获得洞察动力学和聚合过程的机制。我们的解释是支持原子力显微镜和密度泛函理论。形成的聚合物网络的C=O伸展作为红外探针的频率的变化证明。然而，光谱和动力学分析显示，在单分子膜的两相过程。在这两个阶段中，观察到CH 2伸展信号的损失，这与二乙炔聚合的链增长的公认机制不一致。这些信号在第二阶段占主导地位，并被分配到终止反应与分子内连续反应的一些贡献。这一发现现在提供了一个光谱测量的身份和完整性的纳米膜补充显微镜分析。我们推断，有限的二维流动性的固体支持促进分子内终止导致更小的域。
2D Nanomembranes are promising materials for filtration or separation by providing the basis for controlled and rapid transport between two compartments. The polymerization by UV light of diacetylene-containing lipids at an interface produces freestanding 2D nanomembranes. Here, we analyzed in situ the nanomembrane formation of 1,2-bis(10,12-tricosadiynoyl)- sn-glycero-3-phosphocholine (DiynePC) and 1-palmitoyl-2-(10,12-tricosadiynoyl)- sn-glycero-3-phosphoethanolamine (PTPE) on germanium using light-induced infrared difference spectroscopy with attenuated total reflection to obtain insights into kinetics and mechanism of the polymerization process. Our interpretation is supported by atomic force microscopy and density functional theory. Formation of the polymer network is evidenced by changes in frequency of C=O stretches acting as infrared probes. However, spectral and kinetic analysis revealed a biphasic process in the monolayer. In both phases, losses in signal of CH2 stretches are observed which are not in agreement with the accepted mechanism of chain propagation for diacetylene polymerization. These signals are dominant in the second phase and are assigned to termination reactions with some contributions from intramolecular consecutive reactions. This finding now provides a spectroscopic measure for the identity and integrity of the nanomembrane complementary to microscopic analysis. We deduce that limited 2D mobility on the solid support promotes intramolecular termination leading to smaller domains.