Separations with protein liquid crystals



A lyotropic protein liquid crystal was studied experimentally to evaluate its potential as a selective liquid membrane. Concentrated solutions of fibrinogen had nematic like properties under shear and exhibited graded selectivities toward solutes of widely differing sizes when subjected to a two-dimensional velocity field. The magnitude of the selectivity differences was found to depend on the shear orientated direction of the liquid crystal layer. The selectivity seems to be both a solubility phenomena and a relative diffusion phenomena. These anisotropic layers may have potential as controlled variable selectivity membranes.