Many transport mechanism models have been proposed such as the space-charge model, the electrostatic and steric-hindrance model, Donnan steric pore model and dielectric exclusion etc.

• >仪器和设备都已用于膜的结构表征，但仍有一些参数 表征非常困难，制定规范化的测试标准和探索新的表征方法都有重要的意义。