Department of Macromolecular Science and Engineering, Graduate School of Science & Technology, Kyoto Institute of Technology Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.
Ultrasonics. 2011 Feb;51(2):215-22. doi: 10.1016/j.ultras.2010.08.005. Epub 2010 Aug 21.
Ultrasound spectroscopy is a powerful tool to investigate the viscoelastic properties of materials. The longitudinal elastic moduli M' and M(″), or the adiabatic compressibility κ(S) can be evaluated from ultrasound velocity v and attenuation coefficient α via the relation M'=ρv(2) and M(″)=2ραv(3)/ω, where ρ is the density and ω is the angular frequency. So far, the density was independently measured by other equipments or its variation during the chemical reaction has been ignored in the previous literatures. Here we propose a multiple echo method to simultaneously evaluate α, v, ρ, from a single acquisition, enabling us to monitor the polymerization process of acrylamide, where the three parameters vary independently during the reaction. This allows us to analyze the time evolution of the acoustic parameters for polymeric or gelling systems with the better understanding.
超声光谱是研究材料粘弹性性质的有力工具。纵向弹性模量 M'和 M(″)，或绝热压缩率 κ(S)，可以通过超声速度 v 和衰减系数 α 通过关系式 M'=ρv(2)和 M(″)=2ραv(3)/ω来计算，其中 ρ 是密度，ω 是角频率。到目前为止，密度是通过其他设备独立测量的，或者在以前的文献中忽略了其在化学反应过程中的变化。在这里，我们提出了一种多回波方法，可以从单次采集同时评估 α、v、ρ，从而能够监测丙烯酰胺的聚合过程，其中在反应过程中三个参数独立变化。这使我们能够更好地理解分析聚合或胶凝体系的声学参数的时间演化。
