Aqueous self-assembly of arginine and K8SiW11O39: fine-tuning the formation of a coacervate intended for sprayable anticorrosive coatings
Aqueous self-assembly of arginine and K8SiW11O39: fine-tuning the formation of a coacervate intended for sprayable anticorrosive coatings
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精氨酸和 K8SiW11O39 的水自组装：微调用于喷涂防腐涂料的凝聚层的形成
DOI：
10.1039/c9sm01511f
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Lixin Wu
中科院分区：
文献类型：
--
作者：
WEN LI;Xiaohuan Liu;Xiaoming Xie;Zhanglei Du;Bao Li;Lixin Wu
凝聚体通常被认为是由大分子如带相反电荷的聚电解质、蛋白质或肽的液-液相分离形成的。与传统的体系不同，我们在这里展示了一种全新的凝聚体，它是由精氨酸（Arg）和K8[α-SiW 11 O 39]（SiW 11）在水中自组装而成的。凝聚层Arg/SiW 11的形成通过组合技术确认，包括浊度、流变学、光学显微镜、扫描和透射电子显微镜。流变响应的评估表明，复合凝聚层表现出剪切稀化行为。采用X射线光电子能谱（XPS）、傅里叶变换红外光谱（FT-IR）、元素分析和热重分析等方法对凝聚层进行了表征。的凝聚的热力学参数进行监测，通过等温滴定量热法（ITC），它确定的凝聚层的形成，通过混合的Arg和SiW 11是由熵的组合驱动的，和热效应。所得凝聚层显示出典型的上临界溶解温度（UCST）现象，这是强烈依赖于物种的浓度。此外，我们表明，凝聚可以通过化学计量和pH值进行调整。因此，已经构建了使用浊度测量的Arg和SiW 11络合的相图。这样的相图是一个非常有用的工具，从一个特定的组合的精氨酸和SiW 11的凝聚体的制备。最后，探索了酸诱导凝聚层的凝胶化以制备用于保护铜板免受酸蒸气暴露的防腐蚀涂层。
Coacervates are commonly thought to be formed from the liquid–liquid phase separation of macromolecules, such as oppositely charged polyelectrolytes, proteins or peptides. Unlike conventional systems, we here show an entirely novel coacervate obtained from the self-assembly of arginine (Arg) and K8[α-SiW11O39] (SiW11) in water. The formation of the coacervate Arg/SiW11 is confirmed by combined techniques, including turbidity, rheology, optical microscopy, and scanning and transmission electron microscopy. Assessment of the rheological response reveals that the complex coacervate exhibits shear thinning behaviour. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectroscopy, elemental analysis and thermogravimetric analysis are used to characterize the coacervate. The thermodynamic parameters of the coacervation are monitored by isothermal titration calorimetry (ITC), which identifies that the formation of the coacervate by mixing of Arg and SiW11 is driven by a combination of entropic and enthalpic effects. The resultant coacervate shows a typical upper critical solution temperature (UCST) phenomenon, which is strongly dependent on the concentration of the species. Furthermore, we demonstrate that the coacervation could be tuned by stoichiometry and pH. A phase diagram for the complexation of Arg and SiW11 thus has been constructed using turbidity measurements. Such a phase diagram is a very useful tool for the preparation of coacervates from a specific combination of Arg and SiW11. Finally, the acid induced gelation of the coacervate has been explored to fabricate an anticorrosive coating to protect a copper plate from exposure to acid vapour.