In Situ Measurement of Submicron Particles During Synthesis from Gaseous Precursors

表征颗粒尺寸分布、浓度， 气溶胶反应器内的温度对于 正确理解和控制过程。 一期 研究已经证明了一种新的傅里叶变换红外 （FT-IR）发射/透射（E/T）技术来解决 解决了上述问题。 TiO 颗粒在小于1000/cm的波数下强烈吸收， 因此，测量的消光与 粒子质量。 相比之下，大于1000/cm的消光比是 由于散射，并且是粒子的强函数， 粒度分布 利用米氏理论，人们可以 消光光谱估计几何平均直径 在其实际价值的10%以内。 除了粒子质量 E/T FT-IR还可以同时测量颗粒大小 温度以及气体浓度和温度。 第二阶段项目将开发一种在线测量仪器， 亚微米级颗粒的原位分析。 本研究 将（1）改进FT-IR和程序， 优化传输和排放数据的采集， (2)改进和扩展了有关测量的理论 透射光谱与粒径的关系，（3）评价 仪器和分析软件，通过比较红外光谱 与其他颗粒尺寸测量技术的去卷积，以及（4） 在商用TiO 2上现场测试仪器和软件 生产设施。 该提案结合了 三个关键组织：（1）先进燃料研究提供 傅立叶变换红外光谱技术的广泛知识;（2）Hemant教授 Pendse（缅因州大学）是反卷积方面的专家 从衰减光谱的粒度分布;和 (3)Sotiris Pratsinis教授（辛辛那提大学）将 评估FT-IR结果，并将其与常规方法进行比较 颗粒大小测定技术。 上述仪器将进行尺寸测量， 气溶胶以及测量颗粒质量、颗粒 温度、气体组成和气体温度。 的 仪器将坚固耐用、用户友好、便携， 相对便宜。 这种应用程序 仪器包括催化剂载体的合成， 可烧结陶瓷、金属颗粒、光学材料，以及 电子材料。

Characterizing the particle size distribution, concentration, and temperature within an aerosol reactor is essential to the proper understanding and control of the process. Phase I research has demonstrated a novel Fourier transform infrared (FT-IR) emission/transmission (E/T) techniques to address the above problems for the synthesis of TiO particles. TiO particles strongly absorb at wavenumbers less than 1000/cm, and thus the measured extinction is directly proportional to the particle mass. In contrast, extinction above 1000/cm is due to scattering and is a strong function of the particle size distribution. Using Mie theory, one can deconvolute extinction spectra to estimate the geometric mean diameter within 10% of its actual value. In addition to particle mass and size, E/T FT-IR can also simultaneously measure particle temperature as well as gas concentrations and temperature. This Phase II project will develop an instrument for on-line in- situ analysis of submicron sized particles. This research will (1) develop improvements to the FT-IR and procedures to optimize the acquisition of transmission and emission data, (2) improve and extend the theory relating measured transmission spectra to particle size, (3) evaluate the instrument and analysis software by comparing the IR deconvolution to other particle sizing techniques, and (4) field test the instrument and software on a commercial TiO2 production facility. This proposal combines the expertise of three key organizations: (1) Advanced Fuel Research provides its extensive knowledge of FT-IR technology; (2) Prof. Hemant Pendse (University of Maine) is an expert in the deconvolution of particle size distributions from attenuation spectra; and (3) Prof. Sotiris Pratsinis (University of Cincinnati) will evaluate the FT-IR results and compare them to conventional particle sizing techniques. The above instrument will perform size measurements of aerosols as well as measuring particle mass, particle temperature, gas composition, and gas temperature. The instrument will be rugged, user friendly, portable, and relatively inexpensive. The applications for such an instrument include the synthesis of catalyst supports, sinterable ceramics, metal particles, optical materials, and electronic materials.