Structural properties of polymer-brush-grafted gold nanoparticles at the oil-water interface: insights from coarse-grained simulations
Structural properties of polymer-brush-grafted gold nanoparticles at the oil-water interface: insights from coarse-grained simulations
复制标题
油水界面聚合物刷接枝金纳米粒子的结构特性：来自粗粒度模拟的见解
DOI：
10.1039/c5sm02721g
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发表时间：
2016
期刊：
影响因子：
3.4
通讯作者：
Zhou Jian
中科院分区：
文献类型：
--
作者：
Quan Xuebo;Peng ChunWang;Dong Jiaqi;Zhou Jian
在这项工作中，两亲性聚合物刷接枝金纳米粒子（AuNPs）在油-水界面的结构特性进行了研究，通过粗粒模拟。讨论了聚合物刷的接枝结构（二嵌段、混合和Janus刷接枝的AuNP）和亲水性的影响。模拟结果表明，功能化的金纳米粒子呈现出丰富的形貌，包括典型的核-壳结构、Janus型、拟鱼型等，在水或油-水溶剂环境中。结果表明，疏水性/弱亲水性聚合物刷接枝纳米金具有较好的相转移性能，尤其是以疏水性链为外嵌段、弱亲水性链为内嵌段的纳米金。这种金纳米粒子可以穿过界面区，完全进入油相。对于疏水性/强亲水性聚合物刷接枝的金纳米粒子，它们被捕获在界面区域，而不是移动到任何相。相转移的机制归因于外部嵌段的柔性和可移动性。此外，我们还通过PMF分析研究了脱附能。结果表明，Janus刷接枝的AuNPs显示出最高的界面稳定性和活性，这可以通过增加接枝聚合物刷的亲水性来进一步增强。本工作将促进聚合物刷接枝纳米粒子在相转移催化、Pickering乳液催化等方面的工业应用。
In this work, the structural properties of amphiphilic polymer-brush-grafted gold nanoparticles (AuNPs) at the oil–water interface were investigated by coarse-grained simulations. The effects of grafting architecture (diblock, mixed and Janus brush-grafted AuNPs) and hydrophilicity of polymer brushes are discussed. Simulation results indicate that functionalized AuNPs present abundant morphologies including typical core–shell, Janus-type, jellyfish-like, etc., in a water or oil–water solvent environment. It is found that hydrophobic/weak hydrophilic polymer-brush-grafted AuNPs have better phase transfer performance, especially for AuNPs modified with hydrophobic chains as outer blocks and weak hydrophilic chains as inner blocks. This kind of AuNP can cross the interface region and move into the oil phase completely. For hydrophobic/strong hydrophilic polymer-brush-grafted AuNPs, they are trapped in the interface region instead of moving into any phase. The mechanism of phase transfer is ascribed to the flexibility and mobility of outer blocks. Besides, we study the desorption energy by PMF analysis. The results demonstrate that Janus brush-grafted AuNPs show the highest interfacial stability and activity, which can be further strengthened by increasing the hydrophilicity of grafted polymer brushes. This work will promote the industrial applications of polymer-brush-grafted NPs such as phase transfer catalysis and Pickering emulsion catalysis.