纳米TiO2生产及应用现场浓度检.pdfVIP

中国颗粒学会第七届学术年会暨海峡两岸颗粒技术研讨会 th 2010 年 8 月 7 Annual Conference of Chinese Society of Particuology cum Symposium on Particle Technology across Taiwan Straits 超声衰减谱法表征纳米颗粒的粒度分布 呼剑，苏明旭，蔡小舒 (上海理工大学颗粒与两相流测量技术研究所，上海 200093) 摘 要：实验中采用带有石英玻璃阻抗块的高频宽带超声换能器实现了非浸入式测量（Non Destructive Evaluation, NDE ）。为了快速测量纳米颗粒的粒度分布，反演过程中采用了声衰减简 化模型叠加 BLBL 理论模型并结合最优正则化算法，将实测声衰减谱进行反演计算获得了纳米 银悬浊液的粒度分布，并证实了在 50MHz 频率下的理论测量下限可以达到 5nm 。通过提高超声 波频率、增加频带宽度以及提高悬浊液中超声波幅值信号的稳定性等技术手段，实现了纳米级颗 粒粒度分布的准确测量。与 CPS 离心沉降纳米颗粒测量仪、TEM 图像等结果相比较表明超声衰 减谱法测量纳米颗粒的结果是可信的。 关键词: 纳米颗粒；粒度分布；高频超声；超声衰减谱 中图分类号：TB383,TB52 文献标识码：A 文章编号： Measuring of Nanoparticle Size Distribution Based on Broad High-frequency Ultrasonic Attenuation Spectrum Hu Jian, Su Mingxu, Cai Xiaoshu (Institute of Particle Two-phase Flow Measurement, University of Shanghai for Science and Technology, Shanghai, China) Abstract: For the implementation of non destructive evaluation (NDE), a broad high-frequency ultrasonic transducer with a piece of buffer block is utilized in the experiment. In order to measure the size distribution of nanometer particles quickly, the particle size distribution of NanoAg is inversed through the combining among the ultrasonic attenuation simplified model, BLBL theoretical model and the Optimum Regularization Technique (ORT). Three technical approaches including the increasing of frequency, the widening of frequency broad, and the improving of ultrasonic stability are used to achieve the exact ul