一、引言 和常规球状离子交换剂相比,壳-核型交换剂能显著提高离子的传质速度,因而近20年来得到了广泛的应用。例如,在高效色谱分离中薄壳型交换剂作为固定相便是其成功的一例。不过,与传质速度得到提高相联系的是交换容量的必将降低。对分析分离而言,后一影响可以不计,但对制备分离及常量物料富集,则希望传质速度和交换容量同时兼顾,因此需适当选择这 I. Introduction Compared with the conventional spherical ion exchangers, the shell-core exchangers can significantly increase the mass transfer rate of ions, and have been widely used in recent 20 years. For example, the use of thin shell exchangers as stationary phases in high performance chromatographic separations is a successful example. However, in connection with the increase of mass transfer rate, the exchange capacity will surely decrease. For the sake of analytical separation, the latter effect can be neglected. However, for separation of preparation and enrichment of constant materials, the mass transfer rate and exchange capacity should be taken into consideration at the same time, so this