Polymersomes at the solid-liquid interface: Dynamic morphological transformation and lubrication.
Polymersomes at the solid-liquid interface: Dynamic morphological transformation and lubrication.
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DOI：
10.1016/j.jcis.2017.10.065
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发表时间：
2018-02
影响因子：
9.9
通讯作者：
Julia E. Bartenstein;Xiaoyan Liu;K. Lange;P. Claesson;W. Briscoe
中科院分区：
文献类型：
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作者：
Julia E. Bartenstein;Xiaoyan Liu;K. Lange;P. Claesson;W. Briscoe
聚合物囊泡是由某些分子结构的两亲性嵌段共聚物自组装而成的空心球体。虽然它们已被广泛研究用于生物医学应用，但报道其界面特性的研究相对较少。特别是，以前从未报道过聚合物囊泡的润滑。在这里，我们研究了由聚丁二烯-聚环氧乙烷（PBD-PEO；分子量 10,400 g mol−1）自组装的聚合物囊泡在亲水和疏水表面的界面性质。使用定量纳米力学特性映射原子力显微镜 (QNM AFM) 对它们在二氧化硅和云母表面的形态进行成像，并使用胶体探针 AFM (CP-AFM) 研究它们在两个表面之间的约束下介导的摩擦力和表面力。我们发现，聚合物囊泡保持完整，但一旦吸附到云母上，就会采用扁平构象，覆盖率相对较低。然而，在二氧化硅上，这些聚合物囊泡不稳定，破裂形成环形残留物或片状双层。在用 19 nm 聚苯乙烯 (PS) 薄膜疏水化的二氧化硅表面上，与亲水表面相比，聚合物囊泡形成了更稳定的层，具有更高的表面覆盖率，并且界面结构也随着时间的推移而演变。此外，在聚合物囊泡存在下，疏水化二氧化硅表面的摩擦大大减少，表明它们作为有效水性润滑剂的潜力。
Polymersomes are hollow spheres self-assembled from amphiphilic block copolymers of certain molecular architecture. Whilst they have been widely studied for biomedical applications, relatively few studies have reported their interfacial properties. In particular, lubrication by polymersomes has not been previously reported. Here, interfacial properties of polymersomes self-assembled from poly(butadiene)-poly(ethylene oxide) (PBD-PEO; molecular weight 10,400 g mol−1) have been studied at both hydrophilic and hydrophobic surfaces. Their morphology at silica and mica surfaces was imaged with quantitative nanomechanical property mapping atomic force microscopy (QNM AFM), and friction and surface forces they mediate under confinement between two surfaces were studied using colloidal probe AFM (CP-AFM). We find that the polymersomes remained intact but adopted flattened conformation once adsorbed to mica, with a relatively low coverage. However, on silica these polymersomes were unstable, rupturing to form donut shaped residues or patchy bilayers. On a silica surface hydrophobized with a 19 nm polystyrene (PS) film, the polymer vesicles formed a more stable layer with a higher surface coverage as compared to the hydrophilic surface, and the interfacial structure also evolved over time. Moreover, friction was greatly reduced on hydrophobized silica surfaces in the presence of polymersomes, suggesting their potential as effective aqueous lubricants.