摘要 |
A separation method utilizing the ability of temperature-sensitive cross-linked polymer gels to selectively extract solvent from a solution of a macromolecular material. A feed solution containing macromolecules is added to a small amount of gel. The gel swells to absorb the low molecular weight solvent, but it cannot absorb the macromolecules. The raffinate, which is now a concentrated macromolecular solution, is drawn off. To regenerate, the filtered gel is warmed, so that its volume decreases sharply. This suddenly decreased volume occurs because the gel is near a critical point. The solvent is removed from the shrunken gel. The temperature of the gel is then lowered; more feed solution is added; and the cycle is begun again.
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