Establishment of Evaluation Method of Removal Characteristics of Nano-Meter Particles in Gas-Phase.

通过对气相纳米颗粒分离特性评价方法的开发和建立进行了实验研究，得到了以下结果。(1)实验研究了两种制备纳米粒子的方法：一种是基于钛、硅、铝等金属醇盐蒸气的热分解，另一种是基于SO_2/H_2O/N_2混合物的辐解。用差示迁移率分析仪（DNA）和法拉第杯静电计（FCE）测量了生成粒子的数量和尺寸分布。在这些方法中，可以稳定地产生平均直径为2nm左右的纳米尺寸颗粒。(2)为了利用电迁移率分析仪对纳米粒子进行分类，研制了一种新型的电迁移率分析仪（簇型微分迁移率分析仪），成功地对离子和分子簇进行了分类。(3)为了检测带电离子和团簇的浓度，研制了一种新型的法拉第杯静电计，可检测到10^ A以下的团簇带电量<-15>。(4)利用产生的团簇流过滤网或管道，实验评估了去除特性。对于小于约2nm的团簇，团簇粘附到壁上的概率变得小于1。这种回弹特性取决于颗粒和壁面材料。(5)将生成方法与检测方法相结合，可以对气相中纳米颗粒的去除特性进行评价。

From the experimental studies on the development and establishment of the evaluation method of the separation characteristics for nano-meter particles in gas-phase, the following results were obtained.(1) Two types of generation method of nanometer-size particles were developed experimentally : One is based on the thermal decomposition of metal alkoxide vapor such as titanium, silicon and aluminium, and the other on the radiolysis of SO_2/H_2O/N_2 mixture. The number and size distribution of generated particles were measured by the differential mobility analyzer (DNA) and the Faraday cup electrometer (FCE). In these methods, the nanometer size particles around 2nm in average diameter can be generated stably.(2) In order to classify the nanometer-sized particles by the electrical mobility analyzer, a new type of electrical mobility analyzer (Cluster Type Differential Mobility Analyzer) was developed, and the ion and molecular clusters can be classified successfully.(3) In order to detect the concentration of charged ions and clusters, a new type of Faraday cup electrometer was developed and the charged quantity of cluster was detected down to 10^<-15>A.(4) With the generated cluster flowing through the screen or pipe, the removal characteristics were evaluated experimentally. For the clusters smaller than about 2 nm, the sticking probability of clusters onto a wall became smaller than unity. This rebounding characteristics depended on particle and wall materials.(5) Combining the generation method and detection method enabled us to evaluate the removal characteristics of nanomter particles in gas-phase.