Free-standing lipid membranes are promising as artificial functional membrane systems for application in separation, filtration, and nanopore sensing. To improve the mechanical properties of lipid membranes, UV-polymerized lipids have been introduced. We investigated free-standing as well as substrate-supported monolayers of 1-palmitoyl-2-(10,12-tricosadiynoyl)-sn-glycero-3-phosphoethanolamine (PTPE) and 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine (DiynePC) and characterized them with respect to their structure, morphology, and stability. Using helium ion microscopy (HIM), we were able to visualize the integrity of the lipid 2D-nanomembranes spanning micrometer-sized voids under high-vacuum conditions. Atomic force microscopy (AFM) investigations under ambient conditions revealed formation of intact and robust pore-spanning 2D-nanomembranes up to 8 × 2 μm² in size. Analysis by attenuated total reflection–Fourier transform infrared spectroscopy (ATR-FTIR) verified a distinct reduction of signal at 2143 cm^–1 from diacetylene groups in the 2D-nanomembranes after UV-polymerization. Further high-resolution AFM investigations of unpolymerized lipid monolayers revealed a well-ordered two-dimensional network, when deposited on highly oriented pyrolytic graphite (HOPG). These structures were inhibited for polymerized adlayers. Structural models for the molecular arrangement of the adlayers are proposed and discussed.

中文翻译：

---

紫外光聚合的二乙炔脂质的稳健和自由站立的二维纳米膜的表征

独立的脂质膜有望作为人工功能膜系统用于分离，过滤和纳米孔传感。为了改善脂质膜的机械性能，已经引入了紫外线聚合脂质。我们研究了1-palmitoyl-2-（10,12-triosadiynoyl）-sn -glycero-3-phosphoethanolamine（PTPE）和1,2-bis（10,12-tricosadiynoyl）的独立以及受基材支持的单分子层-锡-甘油-3-磷酸胆碱（DiynePC），并对其结构，形态和稳定性进行了表征。使用氦离子显微镜（HIM），我们能够可视化在高真空条件下跨越微米级空隙的脂质2D纳米膜的完整性。在环境条件下原子力显微镜（AFM）调查显示形成完整的和健壮的孔隙跨越2D-纳米薄膜的高达8×2微米²的尺寸。衰减全反射分析-傅立叶变换红外光谱（ATR-FTIR）验证了2143 cm ^–1处信号的明显减少UV聚合后的2D纳米膜中的二乙炔基团 对未聚合脂质单层的进一步高分辨率AFM研究显示，当沉积在高度取向的热解石墨（HOPG）上时，二维网络有序排列。这些结构对聚合的吸附层均具有抑制作用。提出并讨论了吸附层分子排列的结构模型。