2D Self-assembly of an amido-ended hyperbranched polyester induced by platinum ion coordination effect
作者:Daohong Zhang、Junna Li、Jing Wang、Sufang Chen、Jiliang Zhou、Tingcheng Li、Junheng Zhang、Aiqing Zhang、Chuanjun Liu
DOI:10.1039/c3ra42057d
日期:——
Compared with amphiphilic hyperbranched polymers (HBPs), the self-assembly of hydrophilic HBPs remains a challenging area. In this article, we report the self-assembly of an amido-ended, hydrophilic hyperbranched polyester (HTDA-2), by taking advantage of the induction effect of the platinum ion. Self-assembled HTDA-2-Pt polymers are composed of ordered 2D tree-like structures with a diameter of about 500 μm and a trunk-width of approx. 1–2 μm, as shown by transmission/reflection polarizing optical microscopy (TRPOM), scanning electron microscopy (SEM) and dynamic light scattering (DLS). Factors such as temperature, time, solvent, concentration and humidity which influence the morphology of the self-assemblies were investigated using XPS, XRD, SEM, and FT-IR techniques. It is proposed that the coordination between the platinum and oxygen atoms in the amido groups together with hydrogen bonding may induce individual aggregation of core chains and peripheral chains, resulting in micro-phase separation and formation of micelles. These micelles then aggregate and self-assemble into perfect tree-like structures on the surface of a glass substrate in a limited region. The dimension (Df) of about 1.59 for the fractal tree-like morphology suggests perfect fractal behavior of the self-assemblies. Another interesting finding is the appearance of crystal behavior of the tree-like self-assemblies as revealed by XRD analysis.
与两亲性超支化聚合物(HBP)相比,亲水性HBP的自组装仍然是一个具有挑战性的领域。在本文中,我们利用铂离子的诱导效应,报道了氨基端亲水性超支化聚酯(HTDA-2)的自组装。自组装的HTDA-2-Pt聚合物由有序的二维树状结构组成,直径约为500μm,树干宽度约为1-2μm,如透射/反射偏振光学显微镜(TRPOM)、扫描电子显微镜(SEM)和动态光散射(DLS)所示。使用XPS、XRD、SEM和FT-IR技术研究了影响自组装形态的因素,如温度、时间、溶剂、浓度和湿度。研究表明,氨基基团中铂和氧原子之间的配位以及氢键可能会诱导核心链和外围链的单独聚集,从而导致微相分离和胶束的形成。这些胶束随后聚集并自组装成玻璃基板表面有限区域内的完美树状结构。分形树状形态的尺寸(Df)约为1.59,表明自组装具有完美的分形行为。另一个有趣的发现是,XRD分析揭示了树状自组装的晶体行为。