Nanoparticle based ultra-thin membranes have been shown to have remarkable mechanical properties while also possessing novel electrical, optical or magnetic properties, which could be controlled by tailoring properties at the level of individual nanoparticles. Since in most cases the ultra-thin membranes are coupled to some substrates, the role of membrane-substrate interactions, apart from nanoparticle-nanoparticle interactions become very crucial in understanding their mechanical and thermal stability, as well as their plethora of applications. However, systematic studies in this direction have been conspicuously absent. Here we report thermal stability and the corresponding microscopic dynamics of polymer supported ultra-thin membranes comprising of self-assembled, ordered grains of polymer grafted nanoparticles having tunable mechanical properties. The initially ordered membranes show distinct pathways for temperature induced disordering depending on membrane flexibility as well as on interfacial entropic and enthalpic interactions with the underlying polymer thin film. We also observe contrasting temperature dependence of microscopic dynamics of these membranes depending on whether the graft polymer-substrate polymer interactions are predominantly entropic or enthalpic in nature. Our results suggest that apart from their varied applications, the soft nanoparticle-polymer hybrid membranes are a playground for rich physics involving subtle entropic and enthalpic effects along with the nanoparticles softness, which eventually determine their thermo-mechanical stability.

中文翻译：

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软纳米颗粒膜的热稳定性和动力学：熵，焓和膜可压缩性的作用。

已经显示出基于纳米颗粒的超薄膜具有显着的机械性能，同时还具有新颖的电，光或磁性能，可以通过在单个纳米颗粒的水平上调整性能来控制这些性能。由于在大多数情况下，超薄膜都与某些基质偶联，因此，除了了解纳米颗粒与纳米颗粒之间的相互作用外，膜-基质相互作用的作用对于理解其机械和热稳定性以及它们的众多应用也变得至关重要。但是，在这一方向上的系统研究却很缺乏。在这里，我们报道了由自组装的聚合物支撑的超薄膜的热稳定性和相应的微观动力学，具有可调机械性能的聚合物接枝纳米颗粒的有序晶粒。最初排列的膜根据膜的柔韧性以及与下层聚合物薄膜的界面熵和焓相互作用显示出温度引起的紊乱的独特途径。我们还观察到这些膜的微观动力学的温度依赖性不同，这取决于接枝聚合物-底物聚合物相互作用的性质是主要是熵还是焓。我们的结果表明，除了它们的各种应用之外，这种柔软的纳米粒子-聚合物杂化膜还是一个丰富的运动场，涉及微妙的熵和焓效应以及纳米粒子的柔软性，最终决定了它们的热机械稳定性。最初排列的膜根据膜的柔韧性以及与下层聚合物薄膜的界面熵和焓相互作用显示出温度引起的紊乱的独特途径。我们还观察到这些膜的微观动力学的温度依赖性不同，这取决于接枝聚合物-底物聚合物相互作用的性质是主要是熵还是焓。我们的结果表明，除了它们的各种应用之外，这种柔软的纳米粒子-聚合物杂化膜还是一个丰富的运动场，涉及微妙的熵和焓效应以及纳米粒子的柔软性，最终决定了它们的热机械稳定性。最初排列的膜根据膜的柔韧性以及与下层聚合物薄膜的界面熵和焓相互作用显示出温度引起的紊乱的独特途径。我们还观察到这些膜的微观动力学的温度依赖性不同，这取决于接枝聚合物-底物聚合物相互作用的性质是主要是熵还是焓。我们的结果表明，除了它们的各种应用之外，这种柔软的纳米粒子-聚合物杂化膜还是一个丰富的运动场，涉及微妙的熵和焓效应以及纳米粒子的柔软性，最终决定了它们的热机械稳定性。