The routine analysis of polymer blends at the nanoscale is usually carried out using electron microscopy techniques such as scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which often require several sample preparation steps including staining with heavy metals and/or etching. Atomic force microscopy (AFM) is also commonly used, but provides no direct chemical information about the samples analyzed. AFM-IR, a recent technique which combines the AFM's nanoscale resolution with the chemical information provided by IR spectroscopy, is a valuable complement to the already established techniques. Resonance enhanced AFM-IR (contact mode) is the most commonly used measurement mode, due to its signal enhancement and relative ease of use. However, it has severe drawbacks when used in highly heterogenous samples with changing mechanical properties, such as polymer recyclates. In this work, we use the recently developed tapping mode AFM-IR to chemically image the distribution of rubber in a real-world commercially available polyethylene/polypropylene (PE/PP) recycled blend derived from municipal and household waste. Furthermore, the outstanding IR resolution of AFM-IR allowed for the detection of small PP droplets inside the PE phase. The presence of micro and nanoscale particles of other polymers in the blend was also established, and the polymers identified.

中文翻译：

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使用轻敲模式 AFM-IR 对消费后回收聚烯烃共混物进行纳米级化学表征

纳米级聚合物混合物的常规分析通常使用扫描电子显微镜 (SEM) 和透射电子显微镜 (TEM) 等电子显微镜技术进行，这通常需要几个样品制备步骤，包括用重金属染色和/或蚀刻。原子力显微镜 (AFM) 也很常用，但没有提供有关所分析样品的直接化学信息。AFM-IR 是一种将 AFM 的纳米级分辨率与红外光谱提供的化学信息相结合的最新技术，是对已经建立的技术的宝贵补充。共振增强型 AFM-IR（接触模式）是最常用的测量模式，因为它的信号增强和相对易用性。然而，当用于具有不断变化的机械性能的高度异质样品（例如聚合物回收物）时，它具有严重的缺点。在这项工作中，我们使用最近开发的轻敲模式 AFM-IR 对源自城市和生活垃圾的真实市售聚乙烯/聚丙烯 (PE/PP) 回收混合物中橡胶的分布进行化学成像。此外，AFM-IR 出色的红外分辨率允许检测 PE 相内的小 PP 液滴。还确定了共混物中其他聚合物的微米级和纳米级颗粒的存在，并确定了聚合物。我们使用最近开发的轻敲模式 AFM-IR 对来自城市和生活垃圾的真实市售聚乙烯/聚丙烯 (PE/PP) 回收混合物中橡胶的分布进行化学成像。此外，AFM-IR 出色的红外分辨率允许检测 PE 相内的小 PP 液滴。还确定了共混物中其他聚合物的微米级和纳米级颗粒的存在，并确定了聚合物。我们使用最近开发的轻敲模式 AFM-IR 对来自城市和生活垃圾的真实市售聚乙烯/聚丙烯 (PE/PP) 回收混合物中橡胶的分布进行化学成像。此外，AFM-IR 出色的红外分辨率允许检测 PE 相内的小 PP 液滴。还确定了共混物中其他聚合物的微米级和纳米级颗粒的存在，并确定了聚合物。