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固态膜经过五十年代初期的阴、阳离子交换膜,六十年代初期的一、二价阴、阳离子交换膜,以及六十年代末期反渗透、超滤醋酸纤维膜三个发展阶段后,现在已形成了一门膜科学。固态膜由于受其固体本性的限制,特别是在选择性和通量上难以分离物理化学性质很相似的物质。而另一方面,人们又观察到生物在物质输送、浓缩、分离方面的能力是相当令人惊叹的。例如,海带能从海水中富集碘,比海水中碘浓度提高千倍以上;石毛(藻类)能浓缩铀,浓缩率高达750;大肠杆菌体内外钾离子浓度差达3000倍。诸如此类的例子不胜枚举。生物的这种特殊选择和浓缩作用是通过细胞膜来实现的。
After three stages of development of the anion exchange membrane and cation exchange membrane in the early fifties, the primary and secondary anion and cation exchange membranes in the early 1960s and the reverse osmosis and ultrafiltration acetate fiber membranes in the late sixties, Formed a membrane science. Due to the solid nature of the solid film, it is difficult to separate substances of very similar physicochemical properties, especially in terms of selectivity and flux. On the other hand, it is observed that the ability of living things to transport, concentrate, and separate matter is quite impressive. For example, kelp can concentrate iodine from seawater more than a thousand times more than iodine in seawater; stone wool (algae) can enrich uranium with a concentration rate of up to 750; and the concentration of potassium ions in and out of E. coli is up to 3000 times higher. There are numerous examples of this. This special selection and concentration of living things is done through the cell membrane.