Department of Chemical Engineering, University of Washington, Seattle, WA, USA.
Soft Matter. 2018 Jun 27;14(25):5283-5293. doi: 10.1039/c8sm01000e.
Ultrasonic devices are common tools in laboratory and industrial settings to produce cavitation events for cleaning, emulsification, cell lysis and other materials applications. Effects of sonication at the macroscopic scale can be visible while effects at the molecular and nano-scales are not easily probed and, therefore, not fully understood. We present a new small angle scattering sample environment designed specifically to study structural changes occurring in various types of dispersions at the nano-scale due to ultrasonic acoustic waves. The sample environment features two face-to-face high-intensity focused ultrasound transducers coaxially aligned and normal to the neutron/X-ray beam propagation direction. A third broadband transducer is fixed beneath the scattering volume to acoustically monitor for cavitation events. By correlating acoustic data to scattering data, measured structural changes can be correlated to changes in parameters such as frequency, acoustic pressure, or cavitation pressure threshold. Several example applications of colloidal systems effectively influenced by ultrasound fields are also presented to demonstrate the capabilities of the device and to motivate future work on in situ scattering analysis of ultrasound materials processing methods.
超声设备是实验室和工业环境中常用的工具，可用于产生空化现象，以实现清洁、乳化、细胞裂解和其他材料应用。在宏观尺度上，超声的效果是可见的，而在分子和纳米尺度上的效果则不容易探测到，因此也不完全理解。我们提出了一种新的小角散射样品环境，专门用于研究由于超声波而在各种类型的分散体中发生的纳米尺度的结构变化。该样品环境的特点是两个面对面的高功率聚焦超声换能器同轴对准，并垂直于中子/ X 射线束的传播方向。第三个宽带换能器固定在散射体积下方，用于声学监测空化事件。通过将声学数据与散射数据相关联，可以将测量到的结构变化与频率、声压或空化压力阈值等参数的变化相关联。还介绍了几个受超声场有效影响的胶体系统的应用实例，以展示该装置的功能，并为超声材料处理方法的原位散射分析的进一步研究提供动力。
