Development of Testing Method of Performance of Membrane Filters for Dilute Liguidborne Particles

本工作旨在开发和提出各种亚微米直径稀液相颗粒膜过滤器的性能测试方法。用光散射型颗粒计数器测量了不同结构的膜过滤器的颗粒比。本工作得到的主要结论有：1.截留作用作用于直径小于膜过滤器孔径的颗粒的过滤。在去离子水系统中，过滤器之间的孔隙率差异会影响其收集体周围的静电双层的形状。对于纤维状膜过滤器，由于滤液中的离子浓度较高，压缩了捕集体周围的静电双层，导致颗粒透过率下降。这些认识表明，有必要引入一个新的指标来考虑纤维直径、填料密度和过滤器厚度等物理性质，而不是泡点法评定的孔径大小，以预测其对直径小于孔径的颗粒的收集效率。

The present work is aimed at developing and proposing the testing methods on performance of various membrane filters for dilute liquidborne particles with diameter of submirometer. Particle panetrations of membrane filters with various structures were measured with light-scattering type particle counters. Major conclusion obtained by this work are ;1. Interception effect acts on the filtration of particles with diamter smaller than the pore size of membrane filters.2. Since the difference of porosity among filters can have influence on the shape of electrostatic double layr around their collection body in deionized water system.3. For fiber-like membrane filters, particle penetration are subject to decrease because high ion concentration of filtration liquid compresses the electrostatic double layr around their collection body.These understandings suggest that it is necessary to introduce a new index accounting for physical properties such as fiber diameter, packing density and filter thickness instead of pore size rated by the bubble point method in order to predict their collection efficiency for particles with diameter smaller than the pore size.