Tailoring and Understanding the Mechanical Properties of Nanoparticle-Shelled Bubbles
Tailoring and Understanding the Mechanical Properties of Nanoparticle-Shelled Bubbles
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DOI：
10.1021/am502290h
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发表时间：
2014-07-23
影响因子：
9.5
通讯作者：
Lee, Daeyeon
中科院分区：
文献类型：
--
作者：
Brugarolas, Teresa;Gianola, Daniel S.;Lee, Daeyeon
产生具有高比强度和刚度的轻质材料的一种常见方法是将刚性中空微粒（也称为气泡或微球）并入聚合物基质中。这些复合材料的机械性能，也被称为复合泡沫塑料，在很大程度上取决于那些中空微粒。精确控制这些气泡的性质以制造适合特定应用的轻质材料至关重要。在本文中，我们提出了一种方法来定制的机械性能和响应的高度单分散的纳米粒子壳的气泡，使用热处理。我们表征的机械性能的个别组装气泡以及热处理的纳米压痕和定量原位压缩试验。组装气泡显示非弹性响应，而热处理气泡的行为弹性。我们还表明，气泡的刚度和强度显着增强，多达12和14倍的组装气泡，分别通过热处理。我们补充的实验结果与有限元分析（FEA），以了解壳厚度的不均匀性，以及对这些气泡的机械响应和断裂行为的非弹性的影响。我们证明，纳入聚合物复合材料的气泡的故障机制取决于气泡的结构。
One common approach to generate lightweight materials with high specific strength and stiffness is the incorporation of stiff hollow microparticles (also known as bubbles or microballoons) into a polymeric matrix. The mechanical properties of these composites, also known as syntactic foams, greatly depend on those of the hollow microparticles. It is critical to precisely control the properties of these bubbles to fabricate lightweight materials that are suitable for specific applications. In this paper, we present a method to tailor the mechanical properties and response of highly monodisperse nanoparticle-shelled bubbles using thermal treatment. We characterize the mechanical properties of individual as-assembled bubbles as well as those of thermally treated ones using nanoindentation and quantitative in situ compression tests. As-assembled bubbles display inelastic response, whereas thermally treated bubbles behave elastically. We also show that the stiffness and strength of bubbles are enhanced significantly, as much as 12 and 14 times that of the as-assembled bubbles, respectively, via thermal treatment. We complement the experimental results with finite element analysis (FEA) to understand the effect of shell thickness nonuniformity as well as the inelasticity on the mechanical response and fracture behavior of these bubbles. We demonstrate that the failure mechanism of bubbles incorporated into a polymer composite depends on the structure of the bubbles.